Sachin M. Apte

MicroRNAs and their target messenger RNAs associated with endometrial carcinogenesis.

OBJECTIVE Recent advances in gene expression technology have provided insights into global messenger RNA (mRNA) expression changes associated with endometrial cancer development. However, the post-transcriptional events that may also have phenotypic consequences remain to be completely delineated. MicroRNAs (miRNAs) are small non-coding RNA transcripts, that influence cell function via modulation of post-transcriptional activity of multiple target mRNA genes. Although recent reports suggest that miRNAs may influence human cancer development, their role in endometrial carcinogenesis remains to be described. METHODS We measured expression of 335 unique human miRNAs in 61 fresh-frozen endometrial specimens, including 37 endometrial cancers, 20 normal endometrium, and 4 complex atypical hyperplasia samples. In parallel, expression of 22,000 mRNA genes was analyzed using the Affymetrix Human U133A GeneChips in 29 of the endometrial samples, including 20 endometrial carcinomas and 9 normal endometrial samples. Differentially expressed mRNAs, miRNAs, and predicted miRNA-mRNA targets were integrated and evaluated for representation of relevant functional biologic pathways. RESULTS Thirteen miRNAs (p<0.02) and 90 mRNAs (FDR; 0%) were identified to be associated with endometrial cancer development. Twenty-six of the 90 (29%) differentially expressed mRNAs are Sangar-database predicted mRNA targets of the 13 miRNAs. Pathway analysis demonstrates significant involvement of these 26 mRNA genes in processes including cell death, growth, proliferation, and carcinogenesis. CONCLUSION We have identified miRNAs and mRNAs associated with endometrial cancer development. Further, our strategy of integrating miRNA/mRNA data may also aid in the identification of important biologic pathways and additional unique genes that have importance in endometrial pathogenesis.

MicroRNAs and their target messenger RNAs associated with ovarian cancer response to chemotherapy

OBJECTIVE Few successful therapeutic options exist for patients with recurrent ovarian cancer (OVCA). This is due in part to an incomplete understanding of the molecular determinants of chemotherapy-response. Recently, it has been shown that microRNAs (miRNAs) influence messenger-RNA (mRNA) post-transcriptional control and can contribute to human carcinogenesis. The objective of the current study was to explore the role of miRNAs, and their predicted mRNA targets, in OVCA in-vitro response to chemotherapy. METHODS The expression of 335 unique miRNAs was measured in 16 OVCA cell lines. In parallel, the sensitivity of these cell lines to 6 commonly used chemotherapeutic agents (cisplatin, doxorubicin, topotecan, paclitaxel, docetaxel, and gemcitabine) was evaluated by in-vitro cell proliferation assay. MiRNAs associated with cell line drug response were identified by linear regression analysis, and their predicted mRNA targets subject to functional biologic pathway analyses. RESULTS Twenty-seven miRNAs were found to be associated with response to the one or more of the 6 salvage chemotherapies tested (p<0.05). Predicted targets of these miRNAs included 52 mRNAs, previously reported to be associated with chemo-responsiveness, and which are also involved in functional biologic pathways that influence cancer cell cytotoxicity, carcinogenesis, cell mitosis, p53 signaling, and tumor cell growth and invasion. CONCLUSION We have identified miRNAs and their predicted target mRNAs associated with ovarian cancer cell response to chemotherapeutic agents. Our strategy of integrating miRNA and mRNA data may aid in the characterization of important molecular pathways associated with OVCA chemo-response.

Targeting the platelet-derived growth factor receptor in antivascular therapy for human ovarian carcinoma.

Purpose: We sought to determine whether blockade of platelet-derived growth factor receptor (PDGF-R) activation by oral administration of a PDGF-R tyrosine kinase inhibitor (STI571) alone or in combination with i.p. paclitaxel can inhibit the progression of tumors caused by human ovarian carcinoma cells growing in the peritoneal cavity of female nude mice. Experimental Design: In several different experiments, paclitaxel-sensitive and paclitaxel-resistant metastatic human ovarian carcinoma cells were injected into the peritoneal cavity of nude mice. Seven days later, groups (n = 10) of mice began receiving a control treatment, STI571 alone, paclitaxel alone, or a combination of STI571 and paclitaxel. The mice were necropsied after 45 days of treatment. Results: Treatment with combination therapy significantly reduced tumor weight (relative to control or single-agent therapy) in all three human ovarian cancer cell lines. Immunohistochemical analyses revealed that PDGF-R activation was blocked by STI571 administered alone or in combination with paclitaxel. Tumor-associated endothelial cells expressed both PDGF-R and phosphorylated PDGF-R. In mice receiving combination therapy, tumor-associated endothelial cells underwent apoptosis, leading to decreases in microvessel density and tumor cell proliferation relative to control and single-agent therapy. Conclusions: These results show that administration of a PDGF-R tyrosine kinase inhibitor in combination with paclitaxel impairs the progression of ovarian cancer in the peritoneal cavity of nude mice, in part, by blockade of PDGF, an endothelial cell survival factor, which results in the increased apoptosis of tumor-associated endothelial cells.

Fatigue, depression, sleep, and activity during chemotherapy: daily and intraday variation and relationships among symptom changes.

BackgroundPrevious research suggests that cancer patients frequently experience multiple symptoms during chemotherapy; however, relationships among symptom changes are largely unknown.PurposeThe aim of the current study was to examine daily and intraday changes and interrelationships among fatigue, depression, and objectively measured disruptions in sleep and activity during chemotherapy.MethodsParticipants were 78 women with gynecologic cancer. Fatigue, depression, sleep, and activity were assessed the week before and the week after the participants’ first three infusions.ResultsSignificant changes in fatigue, depression, sleep, and activity were observed over time. Before infusions, increases in fatigue were associated with increases in depression. After infusions, increases in fatigue were associated with increases in depression and minutes awake at night, as well as decreases in daytime activity and regularity of sleep/activity patterns (ps < .05).ConclusionsThis study is among the first to track daily and intraday changes in symptoms and interrelationships during chemotherapy. Results indicate that symptoms are interrelated and return to baseline levels after infusions.

Gedunin, a novel natural substance, inhibits ovarian cancer cell proliferation.

The discovery of more active therapeutic compounds is essential if the outcome for patients with advanced-stage epithelial ovarian cancer is to be improved. Gedunin, an extract of the neem tree, has been used as a natural remedy for centuries in Asia. Recently, gedunin has been shown to have potential in vitro antineoplastic properties; however, its effect on ovarian cancer cells is unknown. We evaluated the in vitro effect of gedunin on SKOV3, OVCAR4, and OVCAR8 ovarian cancer cell lines proliferation, alone and in the presence of cisplatin. Furthermore, we analyzed in vitro gedunin sensitivity data, integrated with genome-wide expression data from 54 cancer cell lines in an effort to identify genes and molecular pathways that underlie the mechanism of gedunin action. In vitro treatment of ovarian cancer cell lines with gedunin alone produced up to an 80% decrease in cell proliferation (P < 0.01) and, combining gedunin with cisplatin, demonstrated up to a 47% (P < 0.01) decrease in cell proliferation compared with cisplatin treatment alone. Bioinformatic analysis of integrated gedunin sensitivity and gene expression data identified 52 genes to be associated with gedunin sensitivity. These genes are involved in molecular functions related to cell cycle control, carcinogenesis, lipid metabolism, and molecular transportation. We conclude that gedunin has in vitro activity against ovarian cancer cells and, further, may enhance the antiproliferative effect of cisplatin. The molecular determinants of in vitro gedunin response are complex and may include modulation of cell survival and apoptosis pathways.

A phase II study of GM-CSF and rIFN-γ1b plus carboplatin for the treatment of recurrent, platinum-sensitive ovarian, fallopian tube and primary peritoneal cancer

OBJECTIVE To evaluate the efficacy and toxicity of carboplatin, granulocyte-macrophage colony-stimulating factor (GM-CSF) and recombinant interferon gamma 1b (rIFN-gamma1b) in women with recurrent, platinum-sensitive ovarian, fallopian tube and primary peritoneal cancer. METHODS In this phase II study, patients with recurrent, platinum-sensitive ovarian, fallopian tube or primary peritoneal cancer were treated with subcutaneous GM-CSF and rIFN-gamma1b before and after intravenous carboplatin until disease progression or unacceptable toxicity. All patients had measurable disease and a chemotherapy-free interval >6 months. Response was determined using RECIST criteria and CA 125 levels. RESULTS Between 2003 and 2007, 59 patients received a median of 6 cycles of therapy (range, 1 to 13 cycles). Median age at enrollment was 61 years (range, 35 to 79 years). Median time to progression prior to enrollment was 11 months (range, 6 to 58 months). Of 54 patients evaluable for response, 9 (17%) had a complete response, 21 (39%) had a partial response, and 24 (44%) had progressive disease. The overall response rate was 56% (95% CI: 41% to 69%). With a median follow-up of 6.4 months, median time to progression was 6 months. Myeloid derived cells and platelets increased on day 9 of each chemotherapy cycle. The most common adverse effects were bone marrow suppression, carboplatin hypersensitivity, and fatigue. Responders reported improved quality of life. CONCLUSION This pre and post-carboplatin cytokine regimen resulted in a reasonable response and a hematologic profile that could invite further evaluation of its components in the treatment of patients with ovarian cancer.

A phase II trial of docetaxel and bevacizumab in recurrent ovarian cancer within 12 months of prior platinum-based chemotherapy.

OBJECTIVES The efficacy and safety of bevacizumab and docetaxel were evaluated in women who developed recurrent epithelial ovarian, fallopian, or peritoneal cancer within 12 months of platinum-based therapy. METHODS Patients received docetaxel (40 mg/m(2)) on days 1 and 8 and bevacizumab (15 mg/kg) on day 1 of a 21-daycycle. Primary endpoint was 6-month progression-free survival (PFS). RESULTS Forty-one patients were evaluable for PFS and 38 for best response; 46% had platinum-free intervals (PFI) of <6 months and 54% between 6 and 12 months. The 6-month PFS was 43.9% (95% confidence interval (CI(95%))=28.6-58.2%). Median PFS (months) was 5.2 (CI(95%)=4.4-7.2) for all patients, 6.2 (CI(95%)=4.1-7.4) for patients with PFI <6 months, and 5.1 (CI(95%)=3.0-7.2) for those with PFI ≥ 6 months. Twenty-two patients showed overall response (CR+PR) (57.9%; CI(95%)=40.8-73.7%), and 32 showed clinical benefit (CR+PR+SD) (84.2%; CI(95%)=68.8-94.0%). For those with complete or partial responses, median duration of response was 4.8 months (0.7-14.5). Median overall survival was 12.4 months (CI(95%)=10.0-21.9). The most common grade 3/4 adverse events (AEs) were neutropenia (14.6% of patients), followed by leukopenia, fatigue, metabolic, and gastrointestinal, with 66% showing any grade 3/4 toxicity. Most common AEs of any grade were gastrointestinal (93%), fatigue (73%), and pain (73%). Four (10%) patients developed hypertension, 1 a gastrointestinal perforation, and another a colovesicular fistula. CONCLUSIONS Bevacizumab and docetaxel administered in patients with recurrent ovarian cancer is an active regimen without new unanticipated toxicities. This combination should be an option for further study or clinical use in recurrent ovarian cancer.

Evaluation of the porcine model to teach various ancillary procedures to gynecologic oncology fellows.

OBJECTIVE The purpose of this study was to subjectively evaluate the adequacy of the porcine model for training gynecologic oncology fellows. STUDY DESIGN Following a defined surgical curriculum, fellow-attending pairs operated on female hogs. A predetermined dataset was collected for each procedure. RESULTS Twenty pigs were operated on. The porcine model was determined to be a good model for laparoscopic lymphadenectomy (11), ureteroneocystostomy (7), repair of vascular injury (11), bowel anastamoses (21), distal pancreatectomy (5), nephrectomy (6), partial hepatectomy (5), diaphram stripping (5), and diaphragmatic resection (4). Two attendings and 1 fellow judged the porcine model to be fair (remaining 11 good) for ileocolonic urinary diversion, mainly due to significant differences in anatomy. Liver mobilization (5) and splenectomy (11) were determined to be fair or poor models by all participants due to the limited attachments in the pig. CONCLUSION The porcine model is adequate for teaching some ancillary gynecologic oncology surgical procedures and is inadequate for others.

A novel c-Met inhibitor, MK8033, synergizes with carboplatin plus paclitaxel to inhibit ovarian cancer cell growth.

Elevated serum levels of hepatocyte growth factor (HGF) and high tumor expression of c-Met are both indicators of poor overall survival from ovarian cancer (OVCA). In the present study, we evaluated the role of the HGF signaling pathway in OVCA cell line chemoresistance and OVCA patient overall survival as well as the influence of HGF/c-Met signaling inhibition on the sensitivity of OVCA cells to combinational carboplatin plus paclitaxel therapy. The prevalence of the HGF receptor, c-Met, was determined by immunohistochemistry in primary OVCA samples (n=79) and OVCA cell lines (n=41). The influence of the c-Met-specific inhibitor MK8033 on OVCA cell sensitivity to combinations of carboplatin plus paclitaxel was examined in a subset of OVCA cells (n=8) by CellTiter-Blue cell viability assays. Correlation tests were used to identify genes associated with response to MK8033 and carboplatin plus paclitaxel. Identified genes were evaluated for influence on overall survival from OVCA using principal component analysis (PCA) modeling in an independent clinical OVCA dataset (n=218). Immunohistochemistry analysis indicated that 83% of OVCA cells and 92% of primary OVCA expressed the HGF receptor, c-Met. MK8033 exhibited significant anti-proliferative effects against a panel of human OVCA cell lines. Combination index values determined by the Chou-Talalay isobologram equation indicated synergistic activity in combinations of MK8033 and carboplatin plus paclitaxel. Pearsons correlation identified a 47-gene signature to be associated with MK8033-carboplatin plus paclitaxel response. PCA modeling indicated an association of this 47-gene response signature with overall survival from OVCA (P=0.013). These data indicate that HGF/c-Met pathway signaling may influence OVCA chemosensitivity and overall patient survival. Furthermore, HGF/c-Met inhibition by MK8033 represents a promising new therapeutic avenue to increase OVCA sensitivity to carboplatin plus paclitaxel.

BCL2 antagonist of cell death kinases, phosphatases, and ovarian cancer sensitivity to cisplatin

Objective The BCL2 family proteins are critical mediators of cellular apoptosis and, as such, have been implicated as determinants of cancer cell chemo-sensitivity. Recently, it has been demonstrated that the phosphorylation status of the BCL2 antagonist of cell death (BAD) protein may influence ovarian cancer (OVCA) cell sensitivity to cisplatin. Here, we sought to evaluate how kinase and phosphatase components of the BAD apoptosis pathway influence OVCA chemo-sensitivity. Methods Protein levels of cyclin-dependent kinase 1 (CDK1) and protein phosphatase 2C (PP2C) were measured by immunofluorescence in a series of 64 primary advanced-stage serous OVCA patient samples. In parallel, levels of cAMP-dependent protein kinase (PKA), AKT, and PP2C were quantified by Western blot analysis in paired mother/daughter platinum-sensitive/resistant OVCA cell lines (A2008/C13, A2780S/A2780CP, Chi/ChiR). BAD pathway kinase CDK1 was depleted using siRNA transfection, and the influence on BAD phosphorylation and cisplatin-induced apoptosis was evaluated. Results OVCA patient samples that demonstrated complete responses to primary platinum-based therapy demonstrated 4-fold higher CDK1 (p<0.0001) and 2-fold lower PP2C (p=0.14) protein levels than samples that demonstrated incomplete responses. Protein levels of PP2C were lower in the platinum-resistant versus that shown in the platinum-sensitive OVCA cell line sub-clones. Levels of PKA were higher in all platinum-resistant than in platinum-sensitive OVCA cell line sub-clones. Selective siRNA depletion of CDK1 increased sensitivity to cisplatin-induced apoptosis (p<0.002). Conclusion BAD pathway kinases and phosphatases, including CDK1 and PP2C, are associated with OVCA sensitivity to platinum and may represent therapeutic opportunities to enhance cytotoxic efficacy.