Ovarian cancer patients are generally diagnosed at stage III/IV, when ascites is common. The volume of ascites positively correlates with the extent of metastasis and negatively with prognosis. Membrane GRP78, a stress-inducible endoplasmic reticulum chaperone which also appears on the plasma membrane (memGRP78) of aggressive cancers, plays a crucial role in the maintenance of embryonic stem cells. Our present study demonstrates that tumor cells isolated from ascites generated by epithelial ovarian cancer (ID8 cells) bearing mice have increased memGRP78 expression compared to ID8 cells in normal culture. We hypothesize that these ascites associated memGRP78+ cells are cancer stem-like cells (CSC) and memGRP78 is functionally important in CSCs. Supporting this hypothesis, we show that memGRP78+ cells isolated from ascites have increased sphere forming and tumor initiating abilities compared to memGRP78- cells. When the tumor microenvironment is recapitulated by adding ascites fluid to cell culture, ID8 cells express more memGRP78 and increased self-renewing ability compared to those cultured in medium alone. Moreover, compared to their counterparts cultured in normal medium, ID8 cells cultured in ascites, or isolated from ascites, show an increased expression of stem cell markers Sca-1, Snail and SOX9. Importantly, antibodies directed against the carboxy (COOH)-terminal domain of GRP78 significantly reduce the self-renewing ability of murine and human ovarian cancer cells pre-incubated with ascites, associated with a decreased phosphorylation of Akt and GSK3, and reduced level of the transcriptional factor Snail. Based on this data, we suggest that memGRP78 is a logical therapeutic target for late stage ovarian cancer.
Syngeneic Murine Ovarian Cancer Model Reveals That Ascites Enriches for Ovarian Cancer Stem-Like Cells Expressing Membrane GRP78.
Disease
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Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.
Sex, Specimen part, Cell line, Treatment
View SamplesEpithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 39 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis.
Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.
Sex, Specimen part, Cell line, Treatment
View SamplesEpithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 39 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis.
Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.
Sex, Specimen part, Treatment
View SamplesA phase I trial of a SRC kinase Inhibitor, dasatinib, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer. Background: We conducted a phase I study of dasatinib, an oral SRC tyrosine kinase inhibitor, in combination with paclitaxel and carboplatin in advanced and recurrent epithelial ovarian cancer (EOC). Methods: The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included toxicity, response rate (RR), pharmacokinetics and pharmacodynamics. Based on the 3+3 design, cohorts of 3-6 pts received paclitaxel 175 mg/m2 and carboplatin AUC 6 every three weeks with escalating doses of dasatinib (100, 120, 150 mg daily), followed by an 8 patient expansion cohort. Results: Twenty patients were enrolled between 06/07 and 12/09. The median age was 61 yrs (42-82) with a median of 2 prior regimens (0-6), and 71% had platinum-sensitive disease. There were 3-6 pts in each cohort, and 8 in the expansion cohort. Pharmacokinetics were observed over the first 2 cycles of therapy. One DLT was observed in the 100 mg dasatinib cohort (grade 3 myalgia. Other toxicities in all cycles included neutropenia (95% grade 3-4), thrombocytopenia (35% grade 3-4), and fatigue (10% grade 3). The RR was 45% (complete responses, 3/18(17%); partial responses, 5/18(28%)) and 56% (10/18) had stable disease. The PFS6-month actuarial estimate was 86%. The median PFS and OS were 7.8 and 16.2 months, respectively. Conclusions: Due to the high incidence of myelosuppression with subsequent cycles the recommended phase II dose is 150 mg daily of dasatinib in combination with paclitaxel and carboplatin. The combination was safe with evidence of clinical activity in advanced EOC.
A phase I trial of dasatinib, an SRC-family kinase inhibitor, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer.
Subject
View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
View SamplesGene expression analysis on growing breast cancer cell lines.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
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