Dasatinib (BMS-35482) has synergistic activity with paclitaxel and carboplatin in ovarian cancer cells

Purpose

To explore the activity of dasatinib alone and in combination with paclitaxel and carboplatin in ovarian cancer cells and to determine if dasatinib activity can be predicted based on evaluation of the SRC pathway.

Experimental design

Microarray analysis was performed for IGROV1, OVCAR3, A2780 and SKOV3 ovarian cancer cells and the status of the genomic SRC signature pathway was determined. Cells were treated with carboplatin, paclitaxel and dasatinib individually and in combination. Pre- and post-treatment phospho-SRC (pSRC) and SRC protein expression was determined. Dose-response curves were constructed, and drug interaction was assessed by the Combination Index (CI) method.

Results

SRC protein expression levels reflected the SRC pathway genomic signature in the cell lines with the lowest (SKOV3) and highest (IGROV1) pathway expression, but not in those with intermediate expression (OVCAR3, A2780). Dasatinib treatment caused loss of pSRC in all cell lines, with 50% growth inhibition for IGROV1 at 70 nM, OVCAR3 at 34 nM, A2780 at 4.1 μM and SKOV3 at 530 nM. Dasatinib combined with cytotoxics yielded a synergistic effect (CI = 0.46 to 0.79) in all cell lines except SKOV3.

Conclusion

Dasatinib in combination with standard chemotherapeutic agents appears to interact in a synergistic manner in some ovarian cancer cell lines. Further research is needed to evaluate tumor cell characteristics which predict response to dasatinib.     

Patient reported late effects of gynecological cancer treatment

Objective

There are a large number of gynecological cancer survivors in the United States living with long term sequelae of their treatment. Patient reported outcomes are essential in capturing patients' experiences in order to address survivorship issues; however, patient reported toxicities are not often collected or reported.

Methods

A web-based survivorship care plan tool was used to collect patient reported toxicity data for 390 women who had undergone treatment for gynecological cancer. Demographic, diagnosis, treatment modality and toxicity data were reviewed.

Results

Median age of diagnosis was 49 years, and 88% (n = 334) of the women were Caucasian and had attended at least some college. Only 10% (n = 38) had previously been offered a survivorship care plan or survivorship information. Almost half of the patients had ovarian cancer (46%, n = 180), 23% had cervical cancer (n = 92) and 28% had uterine cancer (n = 109). Late effects most commonly reported for all gynecological malignancy survivors using this tool were cognitive changes, sexual side effects, changes in bowel patterns, peripheral neuropathy and skin changes.

Conclusion

Women with gynecological cancers experience a plethora of late effects; however, very few of them have access to a survivorship plan to cope with these issues. Patient reported side effects, especially sexual dysfunction, occur more commonly than previously reported. Patient-focused tools to evaluate these side effects and access to survivorship plans are needed for comprehensive care of gynecologic cancer survivors.     

MUC16 (CA125) regulates epithelial ovarian cancer cell growth, tumorigenesis and metastasis

Objectives

MUC16 (CA125) protein is a high molecular weight mucin overexpressed in the majority of epithelial ovarian cancers (EOC) but not in the epithelium of normal ovaries suggesting that it might play a role in EOC pathogenesis. Here, we explored the phenotypic consequences of MUC16 knockdown and expression of its C-terminal domain with the aim of establishing a role for MUC16 in tumorigenesis.

Methods

MUC16 was down-regulated by stably expressing an anti-MUC16 endoplasmic reticulum-targeted single-chain antibody which prevented MUC16 cell surface localization in NIH:OVCAR3 cells. In addition, we generated epitope tagged, N-terminal region-deleted MUC16 constructs with (MUC16TMU) and without (MUC16CTD) cytoplasmic tail deletions and stably expressed them in SKOV3 cells.

Results

Although MUC16 knockdown did not affect the cell growth rate, knockdown cells reached a stationary growth phase after 4 days whereas control cells continued to grow for up to 7 days. Colony formation assays in soft agar demonstrated that MUC16 knockdown cells had > 8-fold reduction in their ability to form colonies. Importantly, MUC16 knockdown completely prevents the formation of subcutaneous tumors in nude mice. Conversely, we show that ectopic expression of the MUC16CTD enhances SKOV3 tumor cell growth, colony formation in soft agar and enhances tumor growth and metastases in SCID mice. In addition, MUC16CTD expression increases cell motility, invasiveness, and metastatic property. Deletion of the cytoplasmic tail from the MUC16CTD completely abolished its ability to enhance tumor cell growth, cell motility and invasiveness. Furthermore, the increased invasive properties of MUC16CTD-expressing cells correlated with decreased expression of E-cadherin and increased expression of N-cadherin and vimentin.

Conclusion

These findings provide the first evidence for a critical role of MUC16 in tumor cell growth, tumorigenesis and metastases.     

A novel genome-based approach correlates TMPRSS3 overexpression in ovarian cancer with DNA hypomethylation

Objective

In an attempt to analyze more profoundly aberrant DNA hypomethylation in epithelial ovarian cancer (EOC), we applied a novel genome-based approach which includes expression profiling following pharmacologic stimulation of DNA methylation with the methyl donor S-adenosyl-l-methionine (SAM).

Methods

Four different EOC cell lines (OVCAR3, SKOV3, TOV21 and TOV112) were treated with SAM, and gene expression profiling was performed in SAM-treated and control EOC cells. Genes, downregulated upon SAM treatment were considered as potentially hypomethylated in EOC. DNA hypomethylation was independently validated in ovarian tumor and control tissues by bisulfite sequencing PCR (BSP).

Results

Among the genes identified, one of particular interest was the type II serine protease TMPRSS3 gene variants A and D (TMPRSS3-A/D), previously recognized as overexpressed in EOC and representing potential EOC therapeutic targets. Consecutive BSP analysis demonstrated that the common putative promoter region of the TMPRSS3-A/D gene variants was significantly hypomethylated in high-grade serous EOC tumors, compared to low-malignant potential ovarian tumors and normal ovarian tissue.

Conclusions

Our data imply that TMPRSS3-A/D overexpression in EOC is probably due to hypomethylation of their control region thus indicating that TMPRSS3-A/D variants could also represent novel molecular targets for epigenetic therapy of late stages of the disease. Our results also suggest that the frequently observed upregulation of different members of the type II serine proteases gene family in advanced cancer could be due to aberrant DNA hypomethylation. Furthermore, our study introduces a promising discovery approach that could be used for the identification of hypomethylated genes in different experimental cell models.     

Trends in therapy and survival of advanced stage epithelial ovarian cancer patients in the Netherlands

Objective

The aim of this study was to describe trends in survival and therapy in advanced stage epithelial ovarian cancer (EOC) in the Netherlands and to determine if changes in therapy affected survival.

Methods

All EOC patients diagnosed in the Netherlands during 1989-2009 were selected from the Netherlands Cancer Registry. Differences in treatment over time were tested by the Cochran-Armitage trend test. Multivariable relative survival analyses were performed to test whether changes in treatment are associated with survival.

Results

23,399 EOC patients were diagnosed, of whom 15,892 (67.9%) in advanced stage (stage ≥ 2b). In advanced stage patients, the proportion receiving (neo-)adjuvant chemotherapy and optimal debulking (residuals < 1 cm) increased over time in all age groups. In elderly patients (≥ 75 years) a stable proportion (approximately 28%) did not receive any treatment. Five-year relative survival in advanced stage patients increased from 18% in 1989-1993 to 28% in 2004-2009. In the multivariable model survival improved over time (relative excess risk (RER) of 2004-2009 was 0.71, 95% CI 0.67-0.75 compared to 1989-1993). This RER attenuated to 0.85 (95% CI 0.80-0.90) and 0.91 (95% CI 0.83-0.99) with inclusion of treatment variables in the model (surgery with chemotherapy or optimal surgery with chemotherapy, respectively). This suggests that the improvement was mainly, although not entirely, caused by changes in treatment.

Conclusion

Treatment in advanced stage EOC patients in the Netherlands improved over the last two decades; more patients received (neo)adjuvant chemotherapy and underwent optimal debulking surgery. Changes in treatment led to partial improvement of survival in EOC patients.     

Changes in tumor blood flow as measured by Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) may predict activity of single agent bevacizumab in recurrent epithelial ovarian (EOC) and primary peritoneal cancer (PPC) patients: an exploratory analysis of a Gynecologic Oncology Group Phase II study

Objective

To explore feasibility of measuring tumor blood flow as marker for antiangiogenic activity using DCE-MRI (Dynamic Contrast-Enhanced Magnetic Resonance Imaging) in women with recurrent EOC/PPC treated with bevacizumab.

Methods

In a phase II study, 62 patients with recurrent/persistent EOC/PPC were treated with bevacizumab (15 mg/kg IV q21days) until disease progression. DCE-MRI was performed pre-cycle 1 and 4 of bevacizumab. Images were analyzed retrospectively by a single experienced blinded radiologist. Tumor and muscle contrast enhancement was measured by region of interest signal intensity within the same DCE-MRI images. Flow rates were obtained with concentration of dye as a function of time. Relative blood flow (RBF) was calculated as a ratio of average blood flow into tumor to muscle tissue. Associations between RBF and characteristics/outcomes were explored.

Results

Sixty-two patients were eligible for study. Unfortunately, only 14 (23%) patients had imaging data available for analysis at baseline and 13 of those same patients (21%) had imaging data available for analysis pre-cycle 4. The RBF distribution was similar from pre-cycle 1 to 4. RBF remained stable for the majority of the cases (median change -0.21). Baseline RBF was not significantly associated with being progression-free at 6 months, microvessel density, 17 month overall survival, tumor response, or platinum sensitivity. However, increases in blood flow rates were associated with likelihood to be progression-free at 6 months.

Conclusion

Functional imaging of tumor blood flow is a potential research endpoint that may be explored further. Consideration should be given to timing of endpoint and standardizing the technique.     

Myxoma virus-mediated oncolysis of ascites-derived human ovarian cancer cells and spheroids is impacted by differential AKT activity

Objective

We propose that metastatic epithelial ovarian cancer (EOC) is a potential therapeutic target for the oncolytic agent, Myxoma virus (MYXV).

Methods

Primary EOC cells were isolated from patient ascites and cultured as adherent cells or in suspension using Ultra Low-Attachment dishes. MYXV expressing green fluorescent protein was used to infect cells and spheroids. Infection was monitored by fluorescence microscopy, viral titering and immunoblotting for M-T7 and M130 virus protein expression, and cell viability by alamarBlue assay. Akti-1/2 (5 μM) and rapamycin (20 nM) were used to assay the role of PI3K-AKT signaling in mediating MYXV infection.

Results

Ascites-derived EOC cells grown in adherent culture are effectively killed by MYXV infection. EOC cells grown in suspension to form three-dimensional EOC spheroids readily permit MYXV entry into cells, yet are protected from the cytopathic effects of late MYXV infection. Upon reattachment (to model secondary metastasis), EOC spheroids are re-sensitized to MYXV-mediated oncolysis. The critical determinant that facilitates efficient MYXV infection is the presence of an activated PI3K-AKT signaling pathway. Treatment with the specific AKT inhibitor Akti-1/2 reduces infection of monolayer EOC cells and spheroids. Direct infection of freshly-collected ascites demonstrated that 54.5% of patient samples were sensitive to MYXV-mediated oncolytic cell killing. We also demonstrate that factor(s) present in ascites may negatively impact MYXV infection and oncolysis of EOC cells, which may be due to a down-regulation in endogenous AKT activity.

Conclusions

Differential activity of AKT serves as the mechanistic basis for regulating MYXV-mediated oncolysis of EOC spheroids during key steps of the metastatic program. In addition, we provide the first evidence that MYXV oncolytic therapy may be efficacious for a significant proportion of ovarian cancer patients with metastatic disease.     

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy as upfront therapy for advanced epithelial ovarian cancer: multi-institutional phase-II trial

Objective.

The primary end-point of this multi-institutional phase-II trial was to assess results in terms of overall survival after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in treatment-naive epithelial ovarian cancer (EOC) with advanced peritoneal involvement. Secondary end-points were treatment morbi-mortality and outcome effects of time to subsequent adjuvant systemic chemotherapy (TTC).

Methods.

Twenty-six women with stage III-IV EOC were prospectively enrolled in 4 Italian centers to undergo CRS and closed-abdomen HIPEC with cisplatin and doxorubicin. Then they received systemic chemotherapy with carboplatin (AUC 6) and paclitaxel (175 mg/m²) for 6 cycles.

Results.

Macroscopically complete cytoreduction was achieved in 15 patients; only minimal residual disease (≤ 2.5 mm) remained in 11. Major complications occurred in four patients and postoperative death in one. After a median follow-up of 25 months, 5-year overall survival was 60.7% and 5-year progression-free survival 15.2% (median 30 months). Excluding operative death, all the patients underwent systemic chemotherapy at a median of 46 days from combined treatment (range: 29-75). The median number of cycles per patient was 6 (range: 1-8). The time to chemotherapy did not affect the OS or PFS.

Conclusions.

In selected patients with advanced stage EOC, upfront CRS and HIPEC provided promising results in terms of outcome. Morbidity was comparable to aggressive cytoreduction without HIPEC. Postoperative recovery delayed the initiation of adjuvant systemic chemotherapy but not sufficiently to impact negatively on survival. These data warrant further evaluation in a randomized clinical trial.     

Prognosis of ovarian clear cell carcinoma compared to other histological subtypes: a meta-analysis

Objective

To compare the survival outcome between clear cell carcinoma (CCC) and other histological subtypes in epithelial ovarian carcinoma (EOC).

Methods

From January 1974 to February 2011, we identified a total of 31,800 (CCC; 2152, non-CCC; 29648) patients from 12 studies meeting the inclusion criteria.

Results

Heterogeneity tests demonstrated significant between-study variation (I² = 92.1%) with no significant difference in hazard ratio (HR) for death between CCC and non-CCC (HR; 1.16, 95% CI; 0.85-1.57, random-effects model). Comparing the HR based on stage I + II, and stage III + IV, between CCC and non-CCC, showed that CCC patients had a higher hazard rate for death than those with non-CCC of the ovary (stage I + II; HR; 1.17, 95% CI; 1.01-1.36, stage III + IV; HR; 1.65, 95% CI; 1.52-1.79). In a comparison of CCC and serous EOC, advanced stage (III and IV) CCC only showed a poorer hazard rate for death than serous EOC (HR; 1.71, 95% CI; 1.57-1.86).

Conclusion

This analysis suggests that ovarian CCC patients had poorer prognosis than those with other histological subtypes of EOC, especially in advanced EOC stages. Different treatment strategies may be needed for patients with ovarian CCC.     

Inhibition of cell growth and induction of apoptosis in ovarian carcinoma cell lines CaOV3 and SKOV3 by natural withanolide Withaferin A

Objective

Withaferin A, a natural withanolide, has shown anti-cancer properties in various cancers including breast cancer, but its effects in ovarian cancer remain unexplored. Notch 1 and Notch3 are critically involved in ovarian cancer progression. We decided to examine the effects of Withaferin A in ovarian carcinoma cell lines and its molecular mechanism of action including its regulation of Notch.

Methods

The effects of Withaferin A were examined in CaOV3 and SKOV3 ovarian carcinoma cell lines using MTS assay, clonogenic assay, annexin V/propidium iodide flow cytometry, and cell cycle analysis. Western analysis was conducted to examine the molecular mechanisms of action.

Results

Withaferin A inhibited the growth and colony formation of CaOV3 and SKOV3 cells by inducing apoptosis and cell cycle arrest. These changes correlated with down-regulation of Notch1, Notch3, cdc25C, total and phosphorylated Akt, and bcl-2 proteins.

Conclusions

Withaferin A inhibits CaOV3 and SKOV3 ovarian carcinoma cell growth, at least in part by targeting Notch1 and Notch3.     

Expression of 67-kDa laminin receptor was associated with tumor progression and poor prognosis in epithelial ovarian cancer

Objective

67-kDa laminin receptor (67LR) has been identified as a prognostic biomarker for a variety of human cancers. We investigated the clinical significance of 67LR expression and its functional role in epithelial ovarian cancer (EOC).

Methods

67LR expression was evaluated by immunohistochemistry in 62 patients with EOC. We assessed the correlation of 67LR expression with clinical characteristics. In vitro experiment was performed for 67LR with inhibition using siRNA to evaluate its role in cell survival, apoptosis, and invasion in EOC cells.

Results

67LR was predominantly expressed on the cell membrane in the majority of EOC samples (45/62, 73%). 67LR expression was significantly correlated with advanced stage (P = 0.001). Patients with 67LR expression had shorter progression-free survival among all the patients (P = 0.010) and in particular among patients with advanced stages (P = 0.046). When 67LR expression was inhibited by siRNA in EOC cells (HeyA8 and A2780), there was a significant decrease of cell proliferation and invasion as well as increase of apoptosis.

Conclusion

These findings suggest that 67LR expression may play an important role in tumor progression into advanced stage with poor prognosis in EOC and down-regulation of 67LR on tumor cells may be a therapeutic target in those patients.     

Costunolide induces apoptosis in platinum-resistant human ovarian cancer cells by generating reactive oxygen species

Objective

The acquired resistance to platinum-based drugs has become an obstacle in the management of ovarian cancer. We investigated the apoptosis-inducing effect of costunolide, a natural sesquiterpene lactone, in platinum-resistant human ovarian cancer cells, along with the molecular mechanism of action.

Methods

Costunolide and cisplatin were examined in platinum-resistant human ovarian cancer cells. MTT assay for cell viability, PI staining for cell cycle profiling, and Annexin V assay for apoptosis analysis. ROS production and protein expression was assessed by H₂DCFDA staining and Western blotting, respectively. Combination effect was determined using the Combination Index (CI) method.

Results

It was found that costunolide is more potent than cisplatin in inhibiting cell growth in three platinum-resistant ovarian cancer cell lines (MPSC1^PT, A2780^PT, and SKOV3^PT). Costunolide induced apoptosis of platinum-resistant cells in a time- and dose-dependent manner and suppressed tumor growth in SKOV3^PT-bearing mouse model. In addition, costunolide triggered the activation of caspase-3, -8, and -9. Pretreatment with caspase inhibitors neutralized the pro-apoptotic activity of costunolide. We further demonstrated that costunolide induced a significant increase in intracellular reactive oxygen species (ROS). Additionally, the antioxidant N-acetyl-L-cysteine (NAC) significantly attenuated the costunolide-induced production of ROS, activation of caspases, down-regulation of Bcl-2, and apoptosis in platinum-resistant ovarian cancer cells. Moreover, costunolide synergized with cisplatin to induce cell death in platinum-resistant ovarian cancer cells.

Conclusions

Taken together, these data suggest that costunolide, alone or in combination with cisplatin, may be of therapeutic potential in platinum-resistant ovarian cancer.     

A phase I study of concurrent weekly topotecan and cisplatin chemotherapy with whole pelvic radiation therapy in locally advanced cervical cancer: a gynecologic oncology group study

Purpose

To determine the maximum tolerated dose (MTD) and acute dose-limiting toxicities (DLT) of intravenous topotecan administered with weekly cisplatin during pelvic radiation therapy in patients with locally advanced cervical cancer.

Methods

Patients were treated at one of two dose levels receiving intravenous topotecan at 0.5 mg/m² and cisplatin at either 30 or 40 mg/m² given weekly for 6 weeks concurrently with pelvic radiation and intracavitary brachytherapy. The primary endpoint for the escalation study was acute dose-limiting toxicities occurring within 30 days of completing radiation therapy.

Results

Eleven patients were enrolled. Dose-limiting toxicity consisting of Grade 3 nausea and vomiting lasting > 24 h in one patient and grade 3 febrile neutropenia in another patient occurred at the first dose level of weekly topotecan 0.5 mg/m² and cisplatin 40 mg/m². This necessitated de-escalation to weekly cisplatin 30 mg/m² in combination with topotecan 0.5 mg/m² and pelvic radiation. This dose level was tolerable in 6 evaluable patients with only one DLT consisting of grade 4 thrombocytopenia, grade 3 abdominal pain and grade 3 elevated gamma glutamyl transpeptidase (GGT).

Conclusions

In women with locally advanced cervical cancer, intravenous topotecan 0.5 mg/m² and cisplatin 30 mg/m² given weekly for 6 weeks with concurrent pelvic radiation and intracavitary brachytherapy were tolerable. Further expansion of the feasibility cohort of this study was suspended based on the results of a phase 3 trial comparing the efficacy of platinum combinations in advanced and recurrent cervical cancer.     

A phase II study of a urokinase-derived peptide (A6) in the treatment of persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma: a Gynecologic Oncology Group study

Purpose

This multi-institutional phase II trial assessed the activity and tolerability of the anti-metastatic A6 peptide that binds CD44 in patients with persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma (EOC/FTC/PPC).

Patients and methods

Women with persistent or recurrent EOC/FTC/PPC were eligible for participation if they had measurable disease defined by RECIST criteria, good performance status, and good overall organ function. Patients must have received one prior platinum-based chemotherapeutic regimen and were allowed to have received one additional cytotoxic regimen for the management of recurrent or persistent disease. Women received a 150 mg twice daily subcutaneous dose of A6 and continued on treatment until disease progression or unacceptable toxicity. Primary measures of clinical efficacy were objective tumor response and progression-free survival (PFS) at 6 months. The association of CD44 in archival tissue specimens with clinical outcome was investigated.

Results

Thirty-one eligible patients were evaluated. No responses were observed. Two patients (6.5%) were progression free for at least 6 months. The median PFS was 2.0 months, and median overall survival has not yet been reached. One patient died of hemorrhage which was possibly study related. There were no grade 4 toxicities. The most common grade 3 toxicities were constitutional (2/31; 6.5%). Archival specimens were available for 27 patients, and 5 (18.5%) were CD44 positive by immunohistochemistry. CD44 expression was not associated with the 6-month PFS (p = 0.342).

Conclusion

A6 was well tolerated but had minimal activity in patients with persistent or recurrent EOC/FTC/PPC.     

FDG PET/CT in staging of advanced epithelial ovarian cancer: frequency of supradiaphragmatic lymph node metastasis challenges the traditional pattern of disease spread

Objective

Epithelial ovarian cancer (EOC) spreads intra-abdominally and to the retroperitoneal lymph nodes. A greater number of distant metastases are revealed by ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) compared to conventional imaging methods. We aimed to investigate the presence and anatomic distribution of supradiaphragmatic lymph node metastasis (LNM) detected with pretreatment FDG PET/CT.

Methods

Thirty women with advanced stage (IIC-IV) EOC were scanned with whole body contrast-enhanced FDG PET/CT prior to surgery/neoadjuvant chemotherapy. We performed PET/CT analysis qualitatively and quantitatively. Additionally, contrast-enhanced CT was analyzed blinded to PET/CT scan. Intra-abdominal dissemination was verified by surgery and histopathology. Metabolically active lymph nodes were biopsied when possible. The clinical characteristics of patients with and without supradiaphragmatic LNM were compared.

Results

In 20/30patients (67%) FDG PET/CT detected supradiaphragmatic LNM in one or more locations, whereas conventional CT found LNM in 10 patients (33%). Fourteen patients had parasternal, 14 cardiophrenic, 8 other mediastinal, 6 axillar, and 1 subclavian LNM. Microscopy of all four biopsied lymph nodes (three axillar and one subclavian) confirmed metastatic dissemination. The patients with supradiaphragmatic LNM had significantly more ascites (p < 0.01), higher CA 125 levels, and more frequent subdiaphragmal carcinomatosis (p < 0.03) compared to patients without supradiaphragmatic LNM in preoperative FDG PET/CT.

Conclusions

A significant number of patients with advanced EOC showed supradiaphragmatic LNM in pre-treatment PET/CT. Our findings suggest that the route of EOC cells from the peritoneal cavity to the lymphatic system permeates the diaphragm mainly to the cardiophrenic and continues to parasternal lymph nodes.     

Analyses of merlin/NF2 connection to FAK inhibitor responsiveness in serous ovarian cancer

Objective

Focal adhesion kinase (FAK) is overexpressed in serous ovarian cancer. Loss of merlin, a product of the neurofibromatosis 2 tumor suppressor gene, is being evaluated as a biomarker for FAK inhibitor sensitivity in mesothelioma. Connections between merlin and FAK in ovarian cancer remain undefined.

Methods

Nine human and two murine ovarian cancer cell lines were analyzed for growth in the presence of a small molecule FAK inhibitor (PF-271, also termed VS-6062) from 0.1 to 1 μM for 72 h. Merlin was evaluated by immunoblotting and immunostaining of a human ovarian tumor tissue array. Growth of cells was analyzed in an orthotopic tumor model and evaluated in vitro after stable shRNA-mediated merlin knockdown.

Results

Greater than 50% inhibition of OVCAR8, HEY, and ID8-IP ovarian carcinoma cell growth occurred with 0.1 μM PF-271 in anchorage-independent (p < 0.001) but not in adherent culture conditions. PF-271-mediated reduction in FAK Y397 phosphorylation occurred independently of growth inhibition. Suspended growth of OVCAR3, OVCAR10, IGROV1, IGROV1-IP, SKOV3, SKOV3-IP, A2780, and 5009-MOVCAR was not affected by 0.1 μM PF-271. Merlin expression did not correlate with serous ovarian tumor grade or stage. PF-271 (30 mg/kg, BID) did not inhibit 5009-MOVCAR tumor growth and merlin knockdown in SKOV3-IP and OVCAR10 cells did not alter suspended cell growth upon PF-271 addition.

Conclusions

Differential responsiveness to FAK inhibitor treatment was observed. Intrinsic low merlin protein level correlated with PF-271-mediated anchorage-independent growth inhibition, but reduction in merlin expression did not induce sensitivity to FAK inhibition. Merlin levels may be useful for patient stratification in FAK inhibitor trials.     

The impact of disease distribution on survival in patients with stage III epithelial ovarian cancer cytoreduced to microscopic residual: a Gynecologic Oncology Group study

Objective

To assess the survival impact of initial disease distribution on patients with stage III epithelial ovarian cancer (EOC) cytoreduced to microscopic residual.

Methods

We reviewed data from 417 stage III EOC patients cytoreduced to microscopic disease and given adjuvant intravenous platinum/paclitaxel on one of three randomized Gynecologic Oncology Group (GOG) trials. We subdivided patients into three groups based on preoperative disease burden: (1) minimal disease (MD) defined by pelvic tumor and retroperitoneal metastasis (2) abdominal peritoneal disease (APD) with disease limited to the pelvis, retroperitoneum, lower abdomen and omentum; and (3) upper abdominal disease (UAD) with disease affecting the diaphragm, spleen, liver or pancreas. We assessed the survival impact of potential prognostic factors, focusing on initial disease distribution using a proportional hazards model and estimated Kaplan-Meier survival curves.

Results

The study groups had similar clinicopathologic characteristics. Median overall survival (OS) was not reached in MD patients compared to 80 and 56 months in the APD and UAD groups (P < 0.05). The five-year survival percentages for MD, APD, and UAD were 67%, 63%, and 45%. In multivariate analysis, the UAD group had a significantly worse prognosis than MD and APD both individually and combined (Progression Free Survival (PFS) Hazards Ratio (HR) 1.44; P = 0.008 and OS HR 1.77; P = 0.0004 compared to MD + APD).

Conclusion

Stage III EOC patients with initial disease in the upper abdomen have a worse prognosis despite cytoreductive surgery to microscopic residual implying that factors beyond cytoreductive effort are important in predicting survival.     

Tyrosine kinase A receptor (trkA): a potential marker in epithelial ovarian cancer

Objectives

To evaluate the role of trkA receptor as a potential tumor marker in serous epithelial ovarian cancer and its relationship with the angiogenic factors expression as vascular endothelial growth factor (VEGF) and nerve growth factor (NGF). Additionally, to examine whether NGF and VEGF secreted by epithelial ovarian cancer (EOC) explants and from epithelial ovarian cancer cell line (A2780) are involved in the process of angiogenesis, such as cellular proliferation, migration and differentiation of the human endothelial cell line (EA.hy926).

Methods

The mRNA levels of VEGF, NGF and trkA receptors were measured using PCR in 60 ovarian samples. Cellular localization and semi-quantitative estimation of VEGF, NGF, total trkA and p-trkA was performed using IHC in epithelial cells. NGF, total trkA and p-trkA protein were also evaluated in endothelial cells from the same tissues. Human endothelial cell line EA.hy926 was cultured with conditioned media obtained from both EOC explants and from the A2780 cell line, with or without NGF stimulus.

Results

Significantly higher levels of NGF, total trkA and p-trkA protein expressions were observed in epithelial and endothelial cells in poorly differentiated EOC versus normal ovary. Interestingly, the p-trkA receptor expression level showed the most significant difference and its presence was only found in borderline tumor and EOC samples indicating the importance of trkA receptor in EOC as a potential tumor marker.A significant increase in proliferation, migration and differentiation of EA.hy926 cells was observed with NGF, and this effect was significantly reverted when NGF was immuno-blocked and when a trkA inhibitor was used, showing that NGF is an important angiogenic factor in EOC by activating its trkA receptor.

Conclusion

These results indicate that p-trkA may be considered as a new potential tumor marker in EOC, and that NGF may also act as a direct angiogenic factor in EOC.     

nm23 gene polymorphisms are associated with survival of patients with epithelial ovarian cancer but not with susceptibility to disease

Objective

nm23, a tumor metastasis suppressor gene, has been linked to protection against tumorigenesis and tumor metastasis. This study evaluated whether genetic variants in the nm23 gene were associated with susceptibility to epithelial ovarian cancer (EOC) or the clinical outcome of patients.

Methods

A case-control study was performed with 302 patients with epithelial ovarian cancer and 302 control women. According to the genotypes, the outcome in 213 EOC patients was compared. Progression-free survival (PFS) and overall survival (OS) were analyzed with Kaplan-Meier plots and Cox models adjusted for clinical factors.

Results

The case-control analysis showed that the rs16949649 and rs2302254 polymorphisms in the nm23 gene promoter were not associated with the risk of developing EOC. In contrast, survival analysis showed that the rs2302254 C/T polymorphism was related to the prognosis of EOC patients. Compared with patients carrying the C/C genotype, patients carrying the T/T genotype had a shorter median PFS and median OS by Kaplan-Meier plots and Cox models adjusted for clinical factors. For rs16949649 T/C polymorphisms, Kaplan-Meier analysis indicated that patients carrying the homozygous C/C genotype had shorter PFS and OS than those carrying the T allele (T/T + T/C genotype). The Cox proportional hazard model analysis suggested that this relationship was only retained in OS when adjusted for clinical factors.

Conclusion

Our studies suggest that rs16949649 and rs2302254 polymorphisms in the nm23 gene promoter may influence the prognosis of patients with epithelial ovarian cancer.