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Amyotrophic Lateral Sclerosis:
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Neurofibromatosis:
Ovarian Cancer:
Peer Reviewed Medical:
Prostate Cancer:
Amyotrophic Lateral Sclerosis
Development of Lead Agents for ALS Treatment in Preclinical Model Systems Based on Differential Gene Expression of IGF-II
Posted February 26, 2010
Ole Isacson, M.D., McLean Hospital, Harvard Medical School
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that can be sporadic (the most common form ~ 90% of cases) and familial (hereditary form ~10% of cases). The neurodegeneration affects only somatic motor neurons (MNs) and not autonomic MNs. Studies in ALS mouse models have indicated that the initiation of neurodegeneration might be due to intrinsic factors associated with motor neurons, whereas astrocytes and microglia can also play an important role in the progression of neurodegeneration. Motor neuron subpopulations are prone to relatively differential vulnerability to neurodegeneration with similar pathology and pattern in both forms of ALS, whether sporadic or familial.
Dr. Ole Isacson has taken a novel approach to targeting ALS drug development by examining differential gene expression in subpopulations of motor neurons. He has previously applied this approach successfully in determining neuroprotection biomarkers in Parkinson's disease. His preliminary data from a rat model of ALS highlighted by cranial nerves oculomotor/trochlear (CN 3/4) complex, hypoglossal nerve (CN 12), and lateral motor column (LMC) MNs in symptomatic SOD1G93A rats versus wild-type rats indicated a slight decline of CN 12 MNs and a larger decline in LMC MNs in symptomatic SOD1G93A rats, while CN3/4 MNs seemed to be unaffected. Dr. Isacson then studied global gene and protein expression of CN3/4, CN12, and LMC of the cervical spinal cord in the normal rat. Analysis of in vitro functional assays demonstrated neuroprotective properties of insulin-like growth factor II (IGF-II) when used as a pretreatment for CN 3/4 MNs. IGF-II protected MNs from glutamate toxicity in a validated in vitro bioassay.
Building on these findings, Dr. Isacson, who received an ALSRP FY07 Therapeutic Development Award, has been developing a screening method for identifying compounds that can upregulate expression of IGF-II and that may have neuroprotective properties. High-throughput screening and polymerase chain reactions (PCR) are used to screen drug-like compounds from selected compound libraries (150,000 compounds) featuring many different drug categories. An initial screen of 1,040 generally FDA-approved drugs using quantitative PCR from MN cultures demonstrated 10% of these drugs have a twofold to sixfold upregulation of IGF-II. Notable drug candidates were found in anti-inflammatory, analgesic, and sex hormone-related drug categories. The high-hit compounds were further evaluated and selected by enhancement of IGF-II-related pathway phenotypes and by an in vitro glutamate toxicity assay, a validated bioassay for vulnerability to excitotoxic neuronal degeneration or MN death common in ALS.
Preliminary analysis of pharmacological and toxicological profiles of the selected candidate drugs are in progress both in vitro and in vivo. Additionally, selected candidate drugs with previously known brain permeability are being examined in both normal and pre-symptomatic SOD1G93A rats and mice for disease progression, behavioral and histopathological analysis. A larger screen of drug compounds with structural analysis and pharmacological and toxicological profiles in animal models will follow. The result of the large study will be an optimized candidate drug with high translational potential to be used as a first-line drug for ALS treatment.
Selected Recent Publications:
Chung CY, Koprich JB, Hallett PJ, and Isacson O. 2009. Functional enhancement and protection of dopaminergic terminals by RAB3B overexpression. Proc Natl Acad Sci U S A. 106(52):22474-22479. [Epub 2009 Dec 10.]
Isacson O. 2009. Cell therapy ahead for Parkinson's disease. Science 326(5956):1060.
Pruszak J, Just L, Isacson O, and Nikkhah G. 2009. Isolation and culture of ventral mesencephalic precursor cells and dopaminergic neurons from rodent brains. Curr Protoc Stem Cell Biol Chapter 2:Unit 2D.5.
Hedlund E and Isacson O. 2008. ALS model glia can mediate toxicity to motor neurons derived from human embryonic stem cells. Cell Stem Cell 3(6):575-576. Review.
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Breast Cancer
A Novel TGFb Mouse Model of Breast Cancer Metastasis
Posted March 18, 2010
Manav Korpal and Yibin Kang, Ph.D, Princeton University, Princeton, New Jersey
More than 90 percent of breast cancer-related deaths are due to metastasis, a process that is dependent on interactions between tumor cells and the stroma of tissue at the metastasis site. To understand the signaling process that underlies breast cancer metastasis, Manav Korpal, recipient of a Fiscal Year 2007 Breast Cancer Research Program Predoctoral Traineeship Award, is focusing on the role of transforming growth factor beta (TGFb) and the Smad pathway. His training with mentor Dr. Yibin Kang, a Fiscal Year 2005 BCRP Era of Hope Scholar Awardee, is fostering his development for a career as a breast cancer researcher, which is the ultimate goal of the Predoctoral Traineeship award mechanism.
Using a novel mouse model in which metastasis and TGFb signaling can be temporally and spatially monitored using non-invasive bioluminescence imaging technology, Mr. Korpal and Dr. Kang are examining TGFb signaling in vivo in breast tumors with tropisms to bone, lung, and brain. The mouse model has enabled them to demonstrate the time-dependent efficacy of anti-TGFb therapeutics on inhibiting the establishment of bone metastases. In addition, they were able to confirm the bone as a paracrine source of pathological TGFb. This mouse model can also be used as an in vivo method to speed preclinical drug development through the evaluation of novel classes of TGFb antagonists that are effective against breast cancer metastasis.
Early disruption of TGFb signaling reduces establishment of bone metastases. a, A schematic illustration of the dual luciferase and Smad-inducible systems. The strength of the TGFb pathway in tumor cells can be controlled by genetic manipulation of Smad4 expression, by direct pharmacological inhibitors of TGFb receptor I kinases or through the use of indirect pharmacological inhibitors that reduce the bioavailability of TGFb in the tumor microenvironment. FLUC, under the control of multiple SBEs, is expressed at low basal levels in the absence of TGFb signaling (TGFb off, top panel; upper right mouse image) relative to the TGFb on condition (bottom panel; lower right mouse image). RLUC is expressed constitutively under the control of the CMV promoter, providing a measure for tumor burden (upper and lower left mouse images). b, Five representative mice from each group are shown in their supine position. Mice from the Dox (–3 d), Dox (d 7) and Dox (d 14) groups have reduced tumor burden in bone relative to untreated and Dox (d 21) mice suggesting that early treatment is more effective than late treatment. c, Gradient of p-Smad2 staining suggests that bone serves as a paracrine source of bioactive TGFb. .
Publications:
Korpal M, Yan J, Lu X, et al. 2009. Imaging transforming growth factor-beta signaling dynamics and therapeutic response in breast cancer bone metastasis. Nat Med 15:960-967.
Links:
Public and Technical Abstracts: A Mouse Model for in Vivo Detection and Disruption of TGF-Beta Signaling in Breast Cancer Metastasis
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Microenvironmental Regulation of Mammary Carcinogenesis
Posted March 10, 2010
Lisa Coussens, Ph.D., University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center
The human immune system serves a role in the prevention of cancer by identifying and
destroying tumor cells; however, there is also evidence that the immune system may
stimulate cancer growth and disease progression. Studies have shown that individuals
suffering from chronic inflammation—wherein leukocytes, also called white blood cells,
migrate incessantly into tissue—have an enhanced risk for cancer and that patients with
malignant tissues containing leukocyte infiltrates tend to have a poor clinical prognosis
compared to those without these infiltrates.
Dr. Lisa Coussens, a Fiscal Year 2006 Era of Hope Scholar awardee, is working to
unravel the molecular mechanisms behind leukocyte infiltration into cancerous tissue
and the subsequent leukocyte-mediated regulation of breast cancer progression. As
part of her studies, Dr. Coussens is examining normal and malignant mammary tissues
from both mice and humans to determine the types of immune cells present and to
identify immune system factors that may mediate cancer. She has found that the
infiltration of CD68+ macrophages, CD4+ and CD8+ T cells, and CD20+ B cells in
human breast tumors parallels with advanced cancer progression and that immune
expression signatures composed of macrophages and T cells could potentially be
predictive for overall patient survival.
Dr. Coussens’ in vivo studies have shown that infiltrating T cells promote metastasis to
the lung in mice and provide evidence that the secretion of interleukin-4 (IL-4) by T cells
enables cancer cells to migrate from the primary tumor site. Furthermore, she observed
that a breast cancer model of mice deficient in leukocyte cysteine protease (cathepsin
C) show a diminished number of lung metastases. Dr. Coussens is working to discern
how T cells and cathepsin C promote lung metastasis and is examining the potential of
cathepsin C expression as a predictive measure of metastasis.
If Dr. Coussens’ work to delineate the molecular mechanisms behind leukocytemediated
regulation of tumor cells is successful, she may potentially reveal molecules
or pathways that could be therapeutic targets and may be used in the treatment of both
primary tumors and metastatic disease.
Publications:
DeNardo DG, Barreto JB, Andreu P, Vasquez L, Tawfik D, Kolhatkar N, and
Coussens LM. 2009. CD4+ T cells regulate pulmonary metastasis of mammary
carcinomas by enhancing protumor properties of macrophages. Cancer Cell.
Links:
Public and Technical Abstracts: Microenvironmental Regulation of Mammary Carcinogenesis
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Priming Breast Tumors for Better Chemotherapeutic Response
Posted February 8, 2010
Ralph Reisfeld, Ph.D., The Scripps Research Institute California
Dr. Ralph Reisfeld received a Fiscal Year 2005 Breast Cancer Research Program Idea Award to investigate a new treatment option for breast cancer. Dr. Reisfeld hypothesized that the eradication of fibroblasts in the tumor stroma by a DNA vaccine that specifically targets the fibroblast activation protein (FAP) could increase uptake and sensitivity to chemotherapeutic agents. Dr. Reisfeld developed an oral vaccine that induces CD8+ T-cell-mediated immune responses against FAP. This vaccine suppressed tumor growth and experimental metastases in mice. When paired with doxorubicin or paclitaxel, the vaccine is more effective than single therapy with these therapeutic agents. Mice that received doxorubicin and vaccine treatment showed a decrease in metastatic infiltration in lung tissue. Dr. Reisfeld also discovered that the combination therapy resulted in increased apoptosis, or cell death, in tumors from these mice but had no detrimental effect on normal tissue. Furthermore, he found several proteins whose expression was reduced after treatment with vaccine and doxorubicin, for example, collagen type I expression, PDGF-C, VEGF-C, and VEGF-A, all known inducers of angiogenesis and lymphangiogenesis. Another beneficial effect of this combination therapy was the reduction of tumor interstitial fluid pressure, which correlates with increased tumor size. This combination therapy, specifically targeting fibroblasts, could bridge the gap between traditional chemotherapies and combinatory strategies for treating metastatic breast tumors.
Publications:
Liao D, Luo Y, Markowitz D, Xiang R, and Reisfeld RA. 2009. Cancer associated fibroblasts promote tumor growth and metastasis by modulating the tumor immune microenvironment in a 4T1 murine breast cancer model. PLoS One 4 (11):e7965.
Links:
Public and Technical Abstracts: Immunotherapy Targeting Tumor Stromal Fibroblasts Improves Chemotherapy of Breast Cancer
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Development and Evaluation of a Novel Radiation Therapy Technique for the Treatment of Vertebrae with Metastatic Lesions
Posted January 14, 2010
Joyce Keyak, Ph.D., University of California, Irvine
Breast cancer cells demonstrate strong predilection for metastasis to bone, especially the spine. Metastases to the spine of cancer patients can result in excruciating pain, vertebral collapse, and neurologic complications. One treatment option for patients with spinal metastases is vertebroplasty, a minimally invasive procedure in which a needle is inserted into the spine to extract the tumor tissue and replace it with bone cement. The cement then hardens to stabilize and restore the bone, often providing immediate pain relief. Usually, this surgical treatment is followed by multiple external beam radiation treatments to kill residual tumor tissue in the bone. Because irradiation of spinal metastases also exposes the spinal cord and nerves to radiation, the dose of radiation that can be delivered to the residual tumor is often limited.
Dr. Joyce Keyak, a Fiscal Year 2006 Synergistic Idea Award recipient, is working on combining radiation treatment with vertebroplasty to deliver more effective, therapeutic doses of radiation to patients afflicted with spinal metastases and to eliminate the need for numerous post-surgical clinical visits to receive radiation treatment. Working with cadaveric human spines, Dr. Keyak is studying the fabrication of radioactive bone cement, which would be injected following removal of cancerous tissue from the spine as a way to administer radiation therapy. Following identification of appropriate radioactive compounds for mixing with bone cement, Dr. Keyak performed studies that showed that the bone near the injected radioactive cement receives a high radiation dose and that the dose decreases rapidly with distance, so that the spinal cord will receive little, if any, radiation. Moving forward, Dr. Keyak plans to design and develop surgical instruments that can be used clinically for this procedure, to continue work on the development of quantitative treatment guidelines, and to apply to the FDA for approval to begin clinical trials. If successful, this work could have an important impact on the treatment of debilitating spinal metastases and improve the quality of life for patients receiving treatment for metastatic disease of the spine.
Part of a model for calculating radiation dose to a vertebra. Radioactive cement is shown as a dark blue circle; the bone is surrounded by a tissue equivalent (shown in red), and the other colors indicate various densities of bone (blue is the most dense and red is the least dense). (Graphic by Tadashi Kaneko, Ph.D., Keyak Laboratory, University of California, Irvine)
Links:
Public and Technical Abstracts: Development and Evaluation of a Novel Radiation Therapy Technique for the Treatment of Vertebrae with Metastatic Lesions
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Neurofibromatosis
Characterizing KEN: A Novel NF2/Merlin Protein Complex Modulating Growth Control
Posted May 3, 2010
Duojia Pan, Ph.D., Johns Hopkins University School of Medicine and Howard Hughes Medical Institute, Baltimore, Maryland
A critical aspect of Neurofibromatosis Type 2 (NF2) research is the identification of downstream effector pathways regulated by the NF2/Merlin tumor suppressor protein. Previous investigations by Dr. Duojia Pan of Johns Hopkins University have identified Kibra, a novel tumor suppressor gene in Drosophila. Dr. Pan has also shown that Kibra, NF2/Merlin, and the related FERM domain protein Expanded (Ex) form a protein complex. The resulting Kibra, Ex, NF2/Merlin (KEN) complex regulates the Hippo pathway, a conserved signaling pathway involved in tissue homeostasis. Hippo signaling is modulated by several tumor suppressors, ultimately resulting in the phosphorylation and inactivation of the oncoprotein Yki (Drosophila)/YAP (mammals). Thus, the functional link between the KEN complex and the Hippo pathway may provide a potential mechanism by which NF2/Merlin functions as a tumor suppressor. With funding from a Fiscal Year 2009 Neurofibromatosis Research Program Investigator-Initiated Research Award, Dr. Pan proposes to further elucidate the molecular mechanism by which the NF2/Merlin tumor suppressor functions together with Ex and Kibra in the context of the Hippo signaling pathway, using Drosophila and mammalian cells as experimental models. This research could offer insight into how NF2/Merlin functions as a tumor suppressor protein, therefore leading, potentially, to better prevention and treatment of NF2.
Link:
Public and Technical Abstracts: Functional Characterization of a Novel NF2/Merlin Protein Complex in Growth Control
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Identification of a New Target and Treatment Compound for NF1-Associated Cancer
Posted March 25, 2010
David H. Gutmann, M.D., Ph.D., Neurofibromatosis Center, Washington University School of Medicine, St. Louis, Missouri
Tumors in the inherited cancer syndrome, neurofibromatosis type 1 (NF1) are characterized by the loss of function of the NF1 gene product, neurofibromin. Neurofibromin functions primarily as a negative regulator of the Ras proto-oncogene with further evidence identifying the mammalian target of rapamycin (mTOR) as being a critical downstream effector of neurofibromin/Ras-induced cell proliferation and tumorigenesis. Previous studies from Dr. David Gutmann's laboratory at the Washington University School of Medicine have identified that Rac1 activation is required for mTOR-dependent growth control.
As there are currently very few Rac1 specific inhibitors for preclinical/clinical study, Dr. Gutmann, with support from a fiscal year 2005 Investigator-Initiated Research Award through the Neurofibromatosis Research Program, explored an alternative approach to identifying new, potent anti-cancer compounds suitable for the treatment of NF1-associated brain tumors. Using an unbiased high-throughput chemical library screen of NF1-deficient malignant peripheral nerve sheath tumor (MPNST) cells, a novel compound, Cucurbitacin-I, was been selected for its cell growth inhibitory and pro-apoptotic effect. Since Cucurbitacin-I is known to inhibit signal transducer and activator of transcription-3 (STAT3) function in other cell types, Dr. Gutmann examined whether STAT3 could play a role in the growth of NF1-associated tumors and Nf1-deficient primary brain cells. Dr. Gutmann identified that neurofibromin negatively regulated STAT3 activity in vitro and in vivo, leading to STAT3 hyperactivation in NF1-deficient cells. Based on their findings, a model for neurofibromin cell growth regulation involving the mTOR/Rac1/STAT3 signaling pathway and the role of STAT3 in controlling transcription, apoptosis, and proliferation were also established. Excitingly, Cucurbitacin-I, via STAT3 inhibition, decreased NF1-deficient MPNST cell and tumor growth in vivo. These novel discoveries may ultimately lead to improved therapeutic approaches for the management of NF1-associated brain tumors.
Publication:
Banerjee S, Byrd JN, Gianino SM, Harpstrite SE, Rodriguez FJ, Tuskan RG, Reilly KM, Piwnica-Worms DR, Gutmann DH. 2010. The neurofibromatosis type 1 tumor suppressor controls cell growth by regulating signal transducer and activator of transcription-3 activity in vitro and in vivo. Cancer Res 70(4):1356-1366.
Link:
Public and Technical Abstracts: Identification and Preclinical Evaluation of New Therapies for NF1 Brain Tumors
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Ovarian Cancer
Use of Novel Technologies to Identify and Investigate Molecular Markers for Ovarian Cancer Screening and Prevention - Paving the Way for the Pacific Ovarian Cancer Research Consortium
Posted April 21, 2010
Nicole Urban, Sc.D., Fred Hutchinson Cancer Research Center, Seattle, Washington
Dr. Nicole Urban, one of the first grant recipients from the Department of Defense (DOD) Ovarian Cancer Research Program (OCRP) has worked extensively in the field of ovarian cancer early detection biomarker discovery and validation. Her goal since 1994 has been to identify a screening strategy to reduce mortality from ovarian cancer through early detection. Her current program in translational ovarian cancer research was built on work funded in 1998 by the OCRP, "Use of Novel Technologies to Identify and Investigate Molecular Markers for Ovarian Cancer Screening and Prevention." Working with Beth Karlan, M.D. at Cedars-Sinai and Leroy Hood, Ph.D., M.D. at the University of Washington, she identified novel ovarian cancer biomarkers including HE4, Mesothelin (MSLN), and SLPI using comparative hybridization methods (1), leading to funding in 1999 from the National Cancer Institute (NCI) for the Pacific Ovarian Cancer Research Consortium (POCRC) Specialized Program of Research Excellence (SPORE) in ovarian cancer. The DOD and NCI funding allowed her to develop resources for translational ovarian cancer research including collection, management, and allocation of tissue and blood samples from women with ovarian cancer, women with benign ovarian conditions, and women with healthy ovaries. The DOD grant provided the foundation for what is now a mature specimen repository that has accelerated the progress of scientists at many academic institutions and industry. Dr. Urban has provided specimens to 133 scientists from academic institutions and 9 industry collaborators, including over 60 from outside institutions. She received the SPORE program Leadership Award in 2005 in recognition of her collaborative approach, and her SPORE grant has been competitively renewed twice.
Building on the work funded by the DOD grant, Dr. Urban developed assays to measure both HE4 (2-4) and MSLN (4-6) in serum. HE4 is an epididymal gene that is consistently overexpressed in ovarian malignancy but not in normal or benign ovarian tissue. Mesothelin is a 40-kDa glycoprotein present on the surface of many different malignancies including the majority of mesotheliomas and ovarian cancers. Using a standard set of blood samples from her repository, Dr. Urban evaluated the diagnostic performance of these (2, 6) and other markers (7-10) and their contribution to a diagnostic marker panel (11). She searched extensively for additional markers that would contribute to a diagnostic panel, identifying MMP7 for which an assay was commercially available (11). The original plate-based HE4 and MSLN assays have been licensed to Fujirebio Diagnostics Inc. (FDI), a diagnostics company that has recently received U.S. Food and Drug Administration approval for HE4 as a recurrence monitoring marker. FDI markets MSLN (as MesoMark) in Australia as a diagnostic marker for mesothelioma. Using specimen-efficient bead-based assays, Dr. Urban has evaluated top markers in preclinical samples to learn which markers give early signal. Working with Garnet Anderson, Ph.D., she used serum samples from the CARET repository, measuring CA125, HE4, MSLN, B7H4, Spondin2, and DCR3 in preclinical specimens from 34 cases and 70 matched controls. A composite marker calculated as the maximum of CA125, HE4, and MSLN begins to separate cases from controls over four years prior to diagnosis (12). Dr. Urban is also leading an inter-institutional effort to introduce the best of the novel markers into a screening protocol. She is conducting the Novel Markers Trial, a prospective randomized Phase I screening trial in high-risk women, in collaboration with Beth Karlan, M.D. (Cedars-Sinai), Jonathan Berek, M.D. (Stanford), Melanie Palomares, M.D. (City of Hope), and Pam Paley, M.D. (Swedish Medical Center).
References:
Schummer M, Ng W, Bumgarner R, et al. 1999. Comparative hybridization of an array of 21,500 ovarian cDNAs for the discovery of genes overexpressed in ovarian carcinomas. Genetics 238(2):375-385.
Hellström I, Raycraft J, Hayden-Ledbetter M, et al. 2003. The HE4 (WFDC2) protein is a biomarker for ovarian carcinoma. Cancer Research 63(13):3695-3700.
Scholler N, Crawford M, Sato A, et al. 2006. Bead-based ELISA for validation of ovarian cancer early detection markers. Clinical Cancer Research 12(7):2117-2124.
Scholler N, Lowe KA, Bergan LA, et al. 2008. Use of yeast-secreted in vivo biotinylated recombinant antibodies (biobodies) in bead-based ELISA. Clinical Cancer Research 14(9):2647-2655.
Scholler N, Fu N, Yang Y, et al. 1999. Soluble member(s) of the mesothelin/megakaryocyte potentiating factor family are detectable in sera from patients with ovarian carcinoma. Proceedings of the National Academy of Science U S A 96(20):11531-11536.
McIntosh M, Drescher C, Karlan B, et al. 2004. Combining CA 125 and SMR serum markers for diagnosis and early detection of ovarian carcinoma. Gynecology Oncology 95(1):9-15.
Goodell V, Salazar LG, Urban N, et al. 2006. Antibody immunity to the p53 oncogenic protein is a prognostic indicator in ovarian cancer. Journal of Clinical Oncology 24(5):762-768 [10.1200/JCO.2005.03.2813].
McIntosh MW, Liu Y, Drescher C, et al. 2007. Validation and characterization of human kallikrein 11 as a serum marker for diagnosis of ovarian carcinoma. Clinical Cancer Research 13(15 Pt 1):4422-4428.
Simon I, Liu Y, Krall KL, et al. 2007. Evaluation of the novel serum markers B7-H4, Spondin 2, and DcR3 for diagnosis and early detection of ovarian cancer. Gynecology Oncology 106(1):112-118.
Thorpe JD, Duan X, Forrest R, et al. 2007. Effects of blood collection conditions on ovarian cancer serum markers. PLoS ONE 2(12):e1281.
Palmer C, Duan X, Hawley S, et al. 2008. Systematic evaluation of candidate blood markers for detecting ovarian cancer. PLoS ONE 3(7):e2633.
Anderson GL, McIntosh MW, Wu L, et al. 2010. Assessing lead time of selected ovarian cancer biomarkers: A nested case-control study. Journal of the National Cancer Institute 102:26-38.
Link:
Public and Technical Abstracts: Use of Novel Technologies to Identify and Investigate Molecular Markers for Ovarian Cancer Screening and Prevention
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Molecular Epidemiology of Ovarian Cancer - Australian Ovarian Cancer Study
Posted April 15, 2010
Peter Bowtell, Ph.D., Peter MacCallum Cancer Centre, Melbourne, Australia
Dr. Peter Bowtell, from the Peter MacCallum Cancer Centre in Melbourne, Australia, was awarded a Fiscal Year 2000 Ovarian Cancer Research Program (OCRP) Program Project Award to study the molecular epidemiology of ovarian cancer. With funds from this award, he and his colleagues formed the Australian Ovarian Cancer Study (AOCS), a population-based cohort of over 2000 women with ovarian cancer, including over 1800 with invasive or borderline cancer. With a bank of over 1100 fresh-frozen tumors, hundreds of formalin-fixed, paraffin-embedded (FFPE) blocks, and very detailed clinical follow-up, AOCS has enabled over 60 projects since its inception, including international collaborative studies in the United States, United Kingdom, and Canada. AOCS has facilitated approximately 40 publications, including those of the founding investigators, most of which have been released in the past two years. Findings resulting from AOCS projects include the identification of:
- Differences in epidemiological risk factors between ovarian, fallopian and primary peritoneal cancer (International Journal of Cancer 2008)
- New ovarian cancer susceptibility loci (Nature Genetics 2009)
- Association between MDR1 genotype and progression-free survival in optimally debulked patients (Clinical Cancer Research 2008)
- Novel molecular subtypes of serous ovarian cancer associated with clinical outcome (Clinical Cancer Research 2008)
- Distinct mechanisms of primary treatment failure in serous ovarian cancer (Clinical Cancer Research 2009)
Since the initial OCRP award, AOCS has also been supported by Australian National Health and Medical Research Council (NHMRC), state-based Cancer Council, and Cancer Australia. AOCS was recently chosen by the NHMRC to contribute to the International Cancer Genome Consortium effort. In 2007, Dr. Peter Bowtell and Dr. Gillian Mitchell were awarded an OCRP Translational Research Partnership Award to examine the frequency of BRCA1 and BRCA2 mutations in the AOCS. Without award of the OCRP Program Project grant, this powerful enabling resource for ovarian cancer research would not have been created.
Clustering of expression data derived from serous and endometrioid tumors originating from the ovary, peritoneum, and fallopian tube. A, a series of 251 from 285 tumors were robustly clustered or classified into six k-means groups (C1-C6). Average linkage hierarchical clustering using a Pearson correlation metric was used to cluster genes based on relative expression across the 251 cancers. Per gene median normalization was used for visualization. B, differentially expressed genes identified by SAM analysis. Genes ordered to show relative position within the hierarchical cluster from A. Green, showing relative under expression; red, relative overexpression. C, differentially expressed genes identified by profiling LCM captured cells from tumor and stroma representing C1 tumor specimens. Genes are ordered based on relative position within the hierarchical cluster (A). Red, overexpressed in stroma; green, overexpressed in the tumor.
Publications:
Olsen CM, Nagle CM, Whiteman DC, et al. 2008. Body size and risk of epithelial ovarian and related cancers: A population-based case-control study. International Journal of Cancer 123:450-456.
Song H, Ramus SJ, Tyrer J, et al. 2009. A genome-wide association study identifies a new ovarian cancer susceptibility locus on 9p22.2. Nature Genetics 41:996-1000.
Johnatty SE, Beesley J, Paul J, et al. 2008. ABCB1 (MDR 1) polymorphisms and progression-free survival among women with ovarian cancer following paclitaxel/carboplatin chemotherapy. Clinical Cancer Research 14:5594-5601.
Tothill RW, Tinker AV, George J, et al. 2008. Novel molecular subtypes of serous and endometrioid ovarian cancer linked to clinical outcome. Clinical Cancer Research 14:5198-5208.
Etemadmoghadam D, deFazio A, Beroukhim R, et al. 2009. Integrated genome-wide DNA copy number and expression analysis identifies distinct mechanisms of primary chemoresistance in ovarian carcinomas. Clinical Cancer Research 15:1417-1427.
Link:
Public and Technical Abstracts: Molecular Epidemiology of Ovarian Cancer
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The Biological Basis for Chemoprevention of Ovarian Cancer - The International Ovarian Cancer Association Consortium
Posted April 6, 2010
Andrew Berchuck, M.D., Duke University, Durham, North Carolina
In 1997 Dr. Andrew Berchuck at Duke University, along with his colleagues, was awarded an Ovarian Cancer Research Program (OCRP) Program Project Award to investigate the biological basis for chemoprevention of ovarian cancer. In 2001, he received another Program Project Award to continue this research.
Although inherited BRCA1 and BRCA2 mutations are responsible for about 10% of ovarian cancer cases, these mutations are carried by less than 1% of the population. Other genetic factors likely exist that increase risk moderately, and by virtue of being more common, they may account for a significant fraction of cases. One of the aims of the Program Project was to perform an ovarian cancer genetic association study to identify common low penetrance risk alleles. Over 1,300 cases and an equal number of age- and race-matched control subjects were accrued to the North Carolina Ovarian Cancer Study.
Although Dr. Berchuck and his research group were thrilled by the enthusiasm with which their study was embraced locally, it became apparent that much larger studies would be needed. As the OCRP Program Project was ending in 2005, Dr. Berchuck and his colleague, Joellen Schildkraut, Ph.D., had the opportunity to help lead the formation of an international Ovarian Cancer Association Consortium (OCAC) that is now comprised of over 20 groups. The consortium meets biannually and is working together to identify and validate single nucleotide polymorphisms (SNPs) that affect disease risk through both candidate gene approaches and genome-wide association studies (GWAS). OCAC reported last year in Nature Genetics the results of the first ovarian cancer GWAS, which identified a SNP in the region of the BNC2 gene on chromosome 9 (Nature Genetics 2009, 41:996-1000.)
Dr. Berchuck and his colleagues envision a future in which reduction of ovarian cancer incidence and mortality will be accomplished by implementation of screening and prevention interventions in women at moderately increased risk. Such a focused approach may be more feasible than population-based approaches, given the relative rarity of ovarian cancer.
Publications:
Song H, Ramus SJ, Tyrer J, et al. 2009. A genome-wide association study identifies a new ovarian cancer susceptibility locus on 9p22.2. Nature Genetics 41:996-1000.
Link:
Public and Technical Abstracts: Biological Basis for Chemoprevention of Ovarian Cancer
Public and Technical Abstracts: Biological Basis for Chemoprevention of Ovarian Cancer
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Peer Reviewed Medical
Understanding the Role of PECAM-1 during Angiogenesis
Posted May 6, 2010
Horace DeLisser, M.D., University of Pennsylvania
Disparate processes ranging from wound healing to tumor growth rely on the formation of new blood vessels, a process known as angiogenesis. Impaired angiogenesis can lead to delayed wound healing, whereas excessive angiogenesis contributes to the growth and spread of tumors. Therefore, correct regulation of angiogenesis is critical, and a better understanding of angiogenesis is crucial for treating a variety of diseases and disorders. Platelet endothelial cell adhesion molecule?1 (PECAM-1) is a transmembrane glycoprotein expressed on endothelial cells that line the circulatory microvessels and that are the central cellular actors during angiogenesis. However, the precise role of PECAM-1 during angiogenesis is not fully understood. During in vivo angiogenesis, endothelial PECAM-1 interacts with proteins it recognizes (ligands); this initiates intracellular signaling cascades that facilitate endothelial cell (EC) motility, without which angiogenesis cannot occur. Dr. DeLisser, Principal Investigator (PI) on a fiscal year 2004 Investigator-Initiated Award through the Department of Defense Peer Reviewed Medical Research Program, believed that these PECAM-1-dependent ligand interactions trigger PECAM-1 activation and subsequent association with the signaling molecule SHP-2. This process, in turn, was theorized to facilitate the recruitment of SHP-2 to the membrane surface where SHP-2 mediates cellular activities that enhance EC motility. Dr. DeLisser has found that administration of an anti-PECAM-1 antibody or the loss of PECAM-1 inhibits EC migration and blood vessel formation in animal models of angiogenesis. This effect occurs without impacting cellular proliferation or survival. He therefore believes that, based on these ongoing studies and other results, therapy targeted at PECAM?1 is likely to be well?tolerated. However, given the important role of PECAM-1 in the recruitment of white blood cells into sites of infection or injury, the PI believes that only human clinical trials will serve to establish the ultimate safety of anti-PECAM-1 therapy.
Publications:
Cao G, Fehrenbach ML, Williams JT. 2009. Angiogenesis in platelet endothelial cell adhesion molecule-1-null mice. Am J Pathol 175(2):903-915.
Fehrenbach M, Cao G, Williams J, et al. 2009. Isolation of murine lung endothelial cells. Am J Physiol Lung Cell Mol Physiol 296:L1096-103.
DeLisser HM. 2007. Targeting PECAM-1 for anti-cancer therapy. Cancer Biol Ther 6:121-122.
Cao G, Savani RC, Fehrenbach M, et al. 2006. Involvement of endothelial CD44 during in vivo angiogenesis. Am J Pathol 169(5):325-336.
DeLisser HM, Helmke BP, Cao G, et al. 2006. Loss of PECAM-1 function impairs alveolarization. J Biol Chem 281(13):8724-8731.
DeLisser HM. 2006. Vascular cell-cell adhesion. In: Encyclopedia of Respiratory Medicine, Laurent GJ and Shapiro SD (Eds.). Elsevier Limited, Oxford, United Kingdom 29-36.
Delisser HM. 2006. The role of the extracellular matrix in angiogenesis. In: Bronchial Vascular Remodeling in Asthma and COPD, Lazaar A. (Ed.). Marcel Dekker, New York 105-125.
Tzima E, Irani-Tehrani M, Kiosses WE, et al. 2005. PECAM-1, VE-cadherin and VEGFR2 cooperate to initiate the endothelial cell-specific response to fluid shear stress. Nature 437:426-431.
Link:
Public and Technical Abstracts: PECAM-1 and Angiogenesis
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Measuring Cortical Interactions in the Autistic Brain
Posted March 9, 2010
Mark Tommerdahl, Ph.D., University of North Carolina at Chapel Hill
A number of neurological disorders including autism have been identified as, or are predicted to be, associated with abnormal connectivity between brain regions. Although the incidence of autism is on the rise, knowledge about the underlying mechanisms of this disorder is incomplete. Further, developing animal models in which to investigate the neurobiological deficits associated with autism is difficult as there are very few objective metrics of the performance of human subjects with autism that can guide animal model development. As such, Dr. Tommerdahl, who received a fiscal year 2006 Investigator-Initiated Research Award through the Department of Defense Peer Reviewed Medical Research Program, is focusing on generating novel measures that reflect differences in underlying cortical circuitry between control subjects and those with autism in order to obtain objective metrics that will facilitate the development of innovative animal models of autism. To accomplish this, Dr. Tommerdahl has designed and fabricated a portable two-point tactile diagnostic stimulator (TPS) that can be used for the assessment of cortical health in subjects with autism. The new device, known as the Cortical Metrics stimulator (CM-1), consists of two independently controlled stimulators, allowing stimuli to be delivered simultaneously to two distinct sites at different amplitudes, frequencies, and/or phases. In addition, the CM-1 automatically detects the skin surface, which provides a more efficient stimulus delivery.
To date, protocols for the operation of the CM-1, such as the two-alternative, forced-choice (2AFC) tracking procedure, have also been developed to facilitate investigations of spatial discrimination in human subjects. Assessment of the amplitude discriminative capacity of human subjects between two stimuli positioned at near-adjacent skin sites demonstrates that the performance of the amplitude discrimination task was significantly degraded when stimuli were delivered simultaneously and were near a subject's two-point limen (threshold). Subjects were, however, able to correctly discriminate between the amplitudes of the two stimuli when delivered sequentially at all inter-probe distances (including those within the two-point limen). In addition, studies focusing on the impact of local cortical-cortical connectivity on information processing in autism have been initiated. In these, the temporal order judgment (TOJ) and temporal discriminative threshold (TDT) were assessed in 10 adult autism subjects and 10 healthy control subjects in the absence and presence of synchronized conditioning vibrotactile stimuli. Data from this study indicate that delivery of simultaneous and synchronized vibrotactile stimuli to near-adjacent skin sites decreases a healthy subject's ability to determine temporal order, whereas autistic subjects do not demonstrate such a decreased capacity in TOJ in the presence of synchronized conditioning stimuli.
Publications:
Zhang Z, Francisco E, Holden JK, et al. 2009. The impact of non-noxious heat on tactile information processing. Brain Res (In press).
Francisco EM, Tannan V, Zhang Z, et al. 2008. Vibrotactile amplitude discrimination capacity parallels magnitude changes in somatosensory cortex and follows Weber's law. Exp Brain Res 191(1):49-56.
Tannan V, Holden JK, Zhang Z, et al. 2008. Perceptual metrics of individuals with autism provide evidence for disinhibition. Autism Res 1(4):223-230.
Tommerdahl M, Tannan V, Holden JK, et al. 2008. Absence of stimulus-driven synchronization effects on sensory perception in autism: Evidence for local underconnectivity? Behav Brain Funct 4:19.
Zhang Z, Tannan V, Holden J, et al. 2008. A quantitative method for determining spatial discriminative capacity. BioMed Eng Online 7:12.
Tommerdahl M, Tannan V, Zachek M, Holden JK, Favorov OV. 2007. Effects of stimulus-driven synchronization on sensory perception. Behav Brain Funct 3:61.
Link:
Public and Technical Abstracts: Cortical-Cortical Interactions and Sensory Information Processing in Autism
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Prostate Cancer
PCRP-Funded Researchers are Revealing the Link between Cholesterol-Lowering Drugs and the Potential Prevention of Advanced Prostate Cancer
Posted April 26, 2010
Lionel Bañez, M.D., Duke University, Durham, North Carolina
Statins, commonly used in the treatment of heart disease, are effective agents for lowering cholesterol levels in the blood. Recent studies suggest that statins may also reduce inflammation. This may be a major benefit, as inflammation is associated with advanced prostate cancer, and increasing evidence suggests that statin use may reduce the risk of advanced prostate cancer. Dr. Lionel Bañez, recipient of Fiscal Year 2006 (FY06) Health Disparity Training-Prostate Scholar Award and FY08 Health Disparity Research Award (Transitioning Investigator Category), considered the link between statins and reduced inflammation and hypothesized that statin use might slow or prevent the progression of prostate cancer to advanced disease by decreasing inflammation within prostate tumors.
To test this hypothesis, Dr. Bañez examined prostate cancer tissues from 236 radical prostatectomy patients, 37 (16%) of whom had used statins for a period of 1 year before surgery. The degree of inflammation in prostate cancer tissues was determined based on the number of inflammatory cells present in the tumors. He found that, in general, inflammatory cells were present in 82% of the prostate tumors and, among these, 36% of the tumors had high numbers of inflammatory cells. Comparison of prostate tumors from statin users and nonusers showed that the tumors from patients who had used statins had lower numbers of inflammatory cells. Dr. Bañez concluded that statin use was significantly associated with lower risk for prostate tumor inflammation, and the lower risk was even more pronounced in those patients who had used high doses of statins.
This is the first study to show an association between preoperative statin use and a reduction of intratumoral inflammation in prostate cancer patients. Although these findings require confirmation in larger clinical studies, the work suggests that statins reduce the risk of developing advanced prostate cancer by preventing inflammation in the tumor.
Publication:
Bañez LL, Klink JC, Jayachandran J, Lark AL, Gerber L, Hamilton RJ, Masko EM, Vollmer RT, Freedland SJ. 2010. Association between statins and prostate tumor inflammatory infiltrate in men undergoing radical prostatectomy. Cancer Epidemiol Biomarkers Prev 19(3),722–728.
Links:
Public and Technical Abstracts: Racial Differences in the Association between Statin Use and Prostate Cancer Progression Following Radical Prostatectomy
Public and Technical Abstracts: Racial Differences in Obesity-Related Hemodilution of Prostate Cancer Serum Markers
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Identifying a Key Culprit in Prostate Cancer Metastasis
Posted March 31, 2010
Karen Cichowski, Brigham and Women's Hospital, Boston, Massachusetts
The majority of the 27,000 deaths caused by prostate cancer each year result from the spread (metastasis) of prostate cancer cells to other parts of the body. There are currently no effective therapies for patients with metastatic prostate cancer. Although much is known about the genetic changes and the intracellular signaling pathways controlling prostate cancer cell growth, very little is known about these processes as they relate to prostate cancer metastasis. Dr. Karen Cichowski, a Fiscal Year 2007 PCRP Idea Development Awardee, demonstrated that DAB2IP (“disabled homolog 2 interacting protein”) is turned off by the process of epigenetic silencing in prostate tumors by a second gene, EZH2, which is upregulated in prostate cancer progression. Of crucial importance, she showed that the gene DAB2IP controls metastatic spread of prostate cancer by coordinately regulating two distinct cell signaling pathways.
To understand the function of DAB2IP in the development of prostate cancer metastasis, Dr. Cichowski used cell models of normal prostate (PrEC) and prostate cancer (PC-3) and found that, consistent with the data from prostate tissues, DAB2IP is expressed in normal cells but is silenced in prostate cancer cells. Normally, PC-3 cells produce metastatic tumors when injected into mice; however when Dr. Cichowski activated expression of the silenced DAB2IP gene in the PC-3 cells, the cells were no longer able to produce tumors in mice. To verify the results, a DAB2IP-specific short hairpin RNA (shRNA) was used to specifically turn off DAB2IP expression in PrEC cells, and when these cells were injected into mice, high-grade invasive and metastatic tumors formed. Similarly, introduction of EZH2 into normal PrEC cells resulted in the silencing of DAB2IP, and mice injected with these cells also developed invasive and metastatic prostate cancer. Dr. Cichowski also demonstrated that silencing of DAB2IP in normal PrEC cells activated both the Ras oncogene pathway and the NF-kB signaling pathway. She found that the Ras oncogene pathway induced uncontrolled cell proliferation, and the activated NF-kB signaling pathway was critical for metastatic spread of prostate cancer. EZH2, therefore, activates the Ras and NF-êB pathways by epigenetically suppressing DAB2IP, providing the molecular mechanism by which an epigenetic regulator activates these two major signaling pathways. Taken together with the data from human tissues, these results suggest a critical role for DAB2IP in suppressing prostate cancer tumor development and metastasis, and reveal EZH2 and DAB2IP as potential biomarkers for progression to metastasis and new therapeutic targets for reducing death and suffering due to prostate cancer.
DAB2IP loss induces prostate cancer metastasis by causing dramatic molecular changes at the invasive front of the tumor. This image shows a DAB2IP-deficient metastatic tumor in mice undergoing an “epithelial to mesenchymal”-like transition at the leading edge of the tumor. Green: the mesenchymalmarker vimentin. Red: the epithelial marker e-cadherin. Blue: DAPI staining of cell nuclei.
Publication:
Min J, Zaslavsky A, Fedele G, McLaughlin SK, Reczek EE, De Raedt T, Guney I,
Strochlic DE, Macconaill LE, Beroukhim R, Bronson RT, Ryeom S, Hahn WC, Loda M,
Cichowski K. 2010. An oncogene-tumor suppressor cascade drives metastatic prostate cancer by coordinately activating Ras and nuclear factor-B. Nature Medicine 16 (3):286-294.
Links:
Public and Technical Abstracts: Elucidating the Function of a New Tumor Suppressor in Prostate Cancer Progression
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Improving Biopsy Techniques in Recurrent Prostate Cancer
Posted March 4, 2010
Cynthia Ménard, M.D., University Health Network, Toronto, Ontario, Canada
For some men, radiation therapy as treatment for early stage prostate cancer is only partially effective, risking continued tumor growth and/or metastasis. Dr. Cynthia Ménard, a Fiscal Year 2005 Prostate Cancer Research Program New Investigator Awardee, investigated the combined use of Magnetic Resonance Imaging (MRI) and prostate needle biopsies to better identify and target any remaining cancerous tissue for salvage therapy. A special MRI table was designed to allow needle placement while the patient was lying on his back (rather than side or stomach) to improve prostate gland stability during the procedure. This table was tested in conjunction with integrated diagnostic and interventional MRI using stereotactic trans-perineal needle navigation for real-time imaging of needle placement. MRI-guided biopsies were performed on thirteen prostate cancer patients with suspected growing tumors who had previously received radiation therapy (median 5.8 years prior), and the procedure was well tolerated by these patients with minimal discomfort.
Using MRI measurements and biopsy results, Dr. Ménard created three-dimensional tumor maps of the prostate gland to correlate diagnostic MRI data with biopsy tissue histology for identification of recurring tumor sites. Ten patients were found to have recurrent disease, with the site of recurrence corresponding to suspicious imaging findings in all but two cases, demonstrating that MRI can spatially delineate local prostate cancer recurrence after radiation treatment. Precise focusing of additional treatment after radiotherapy to areas of recurrent tumor growth within the patient’s prostate gland may help prevent cancer spread, which in turn may translate into improved cure rates with fewer side effects for prostate cancer patients.
In additional ongoing clinical studies funded by this award, Dr. Ménard is using MRI to measure oxygen levels in growing tumors since it is widely accepted that tumors containing low oxygen levels tend to respond differently to therapy. By measuring oxygen in tumors and comparing the results to MRI, physicians may be able to choose and adapt salvage therapies according to the level of oxygen in the tumor in different parts of the prostate gland, further improving prostate cancer cure rates.
MRI-Guided Biopsy. (a) Dedicated interventional MRI table assembly providing pelvic access for stereotactic needle guidance during integrated diagnostic imaging and biopsy. (b) Navigation software (Aegis, Sentinelle Medical, Inc.) displaying needle target highlighted in green (see light green arrow pointing to green target area) onto suspicious dark tumor visible on ADC map. (c) Corresponding anatomic T2 weighted images. (d) Needle verification images documenting actual location of 3 biopsy needles (signal voids R and L) in reference to intended suspicious tumor target highlighted in green. Biopsy confirmed the presence of malignancy.
Links:
Public and Technical Abstracts: Integration of Diagnostic and Interventional MRI for the Study of Persistent Prostate Cancer after External Beam Radiotherapy
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Sunitinib Advances to a Phase III Clinical Trial in Men with Advanced Prostate Cancer
Posted January 27, 2010
M. Dror Michaelson, M.D., Ph.D., Massachusetts General Hospital, Boston, Massachusetts
A drug already in use for treatment of some types of cancer has now been shown to have potential for treating the lethal form of prostate cancer as well. Advanced metastatic castration-resistant prostate cancer (CRPC) develops in a subset of prostate cancer patients and causes an estimated 27,000 deaths per year in the United States. There is an urgent need to develop improved treatments for CRPC. Sunitinib (distributed as Sutent by Pfizer) is a drug that targets growth factor receptors such as those for vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). These receptors are expressed on the surface of endothelial and prostate cancer cells and, upon binding their respective growth factors, activate intracellular pathways controlling cell proliferation. Since inhibition of VEGF slows the growth of CRPC in vitro and in vivo, Dr. Michaelson conducted a Phase II clinical trial of sunitinib in two groups of men with CRPC. Thirty-four patients enrolled in the trial were treated for 12 weeks with sunitinib. Before starting treatment, all patients had rising prostate specific antigen (PSA) values or worsening bone scans; some patients had previously received docetaxel-based chemotherapy. Overall, 4 patients showed declines in PSA value, although this was transient for 2 of the patients, and 3 patients showed radiographic improvements.
Although the treatment was well-tolerated, data on PSA failed to show significant advantage. However, in clinical studies of advanced prostate cancer, increasing evidence suggests that PSA response may not be an adequate indicator of anti-tumor activity. Therefore Dr. Michaelson examined angiogenic biomarkers in patient serum and found significant declines in soluble VEGF receptor, leptin, and PDGF-alpha, which suggested anti-tumor activity, and a significant increase was observed in an anti-angiogenic marker, placental growth factor (P1GF). In addition, analysis of serum biochemical markers of bone formation and resorption showed that bone-specific alkaline phosphatase increased and N-telopeptide decreased after treatment, suggesting that treatment with sunitinib may have an effect on reducing bone resorption. Due to the anti-angiogenic activity of sunitinib in CRPC, an international Phase III clinical trial of sunitinib has been launched in men with docetaxel-resistant metastatic prostate cancer (at www.clinicaltrials.gov - reference number NCT00676650).
Prostate-specific antigen (PSA) and radiological responses in prostate cancer patients 12 weeks after beginning sunitinib treatment. Each bar represents the change in serum PSA from baseline (day 1) to week 12 in individual patients. The bars are color coded based on radiographic response: partial response (PR-dark blue), stable disease (SD-red), progressive disease (PD-light blue), and not accessible (NE-yellow).
Publication:
Michaelson MD, Regan MM, Oh WK, et al. 2009. Phase II study of sunitinib in men with advanced prostate cancer. Annals of Oncology 20: 913-920.
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