First-line chemotherapy in epithelial ovarian cancer. Clin Obstet Gynecol. 2012;55:96-113. [PMID: 22343232 DOI: 10.1097/grf.0b013e31824b45da]

Inhibiting the growth of ovarian cancer cells in vitro and in vivo by a small molecular inhibitor targeting La-RNA interactions

OBJECTIVE

To identify small molecules blocking La-RNA interactions by using structural dynamics, molecular biology, and in vivo efficacy experiments.

METHODS

A docking virtual assay on the Chemdiv database was used to screen La binders, and their affinity were measured by surface plasmon resonance (SPR). A novel fluorescence polarization (FP) assay referring to the binding of La protein and 3'UUUOH was established to identify the inhibitors. Their activity on ovarian cancer cell proliferation, apoptosis and cell cycle were evaluated using Cell Counting Kit 8 (CCK8) and flow cytometry assay, respectively. Their in vivo efficacy against ovarian cancer growth were evaluated in a cell line-derived xenograft (CDX) model of A2780 cells.

RESULTS

From a total of 20 compounds with high potential binding activity with La protein, two small molecule compounds 4424-1120 and 8017-5932 with relatively stronger inhibition ability on La-RNA interactions were identified. These two compounds shared the same active centers with hydroxyimidazole and hydroxybenzene to interact with La protein through residues ARG57, GLN20 and GLN136. The in vitro assays showed that 4424-1120 and 8017-5932 effectively cause G0/G1 cell cycle arrest, inhibit cell proliferation, reduce cell invasion and promote apoptosis in ovarian cancer cells. In a CDX model on BALB/C Nude mice, we found that the growth rate of the tumor was inhibited by 4424-1120.

CONCLUSION

Our results demonstrated compound 4424-1120 shows good antitumor activity and safety in vitro and in vivo, and it provides a new idea for the discovery of antitumor lead compounds from small drug-like molecules.

Salt-Inducible Kinase 2-Triggered Release of Its Inhibitor from Hydrogel to Suppress Ovarian Cancer Metastasis

Salt-inducible kinase 2 (SIK2) is a promising target for ovarian cancer therapy due to its critical role in tumorigenesis and progression. Currently available SIK2 inhibitors have shown remarkable therapeutic effects on ovarian cancers in preclinical studies. However, direct administration of the SIK2 inhibitors may bring significant off-target effect, limiting their clinical applications. In this work, by rational design of a hydrogelator Nap-Phe-Phe-Glu-Glu-Leu-Tyr-Arg-Thr-Gln-Ser-Ser-Ser-Asn-Leu-OH (Nap-S) to coassemble a SIK2 inhibitor HG-9-91-01 (HG), a SIK2-responsive supramolecular hydrogel (Gel Nap-S+HG) for local administration and SIK2-responsive release of HG is reported to efficiently suppress ovarian cancer metastasis. Under the activation of SIK2 overexpressed in ovarian cancers, Nap-S in the hydrogel is phosphorylated to yield hydrophilic Nap-Phe-Phe-Glu-Glu-Leu-Tyr-Arg-Thr-Gln-Ser(H2 PO3 )-Ser-Ser-Asn-Leu (Nap-Sp), triggering the disassembly of the hydrogel and a responsive release of the inhibitor. Cell experiments indicate that sustained release of HG from Gel Nap-S+HG induce a prominent therapeutic effect on cancer cells by inhibiting SIK2 and phosphorylation of their downstream signaling molecules. Animal experiments demonstrate that, compared with those tumor model mice treated with free HG, Gel Nap-S+HG-treatment mice show an enhanced inhibition on ovarian tumor growth and metastasis. It is anticipated that the Gel Nap-S+HG can be applied for ovarian cancer therapy in clinic in the near future.

TEM1-targeting PEGylated PLGA shikonin nanoformulation for immunomodulation and eradication of ovarian cancer

Introduction: Tumor endothelial marker 1 (TEM1) is expressed by tumor vascular endothelial cells in various cancers. Methods: Here, we developed poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) PEGylated with polyethylene glycol (PEG) and functionalized with anti-TEM1 antibody fragment (78Fc) and loaded them with necroptosis-inducing agent shikonin (SHK) (78Fc-PLGA-SHK NPs). Results: The nanoformulation showed a smooth spherical shape (~120 nm; the ζ potential of -30 mV) with high drug entrapment and bioconjugation efficiencies (~92% and ~90%, respectively) and a sustained-release profile in serum. Having significant toxicity in vitro (e.g., MS1 and TC1 cells), the nanoformulation dramatically increased the cytotoxicity in the TC1 murine lung carcinoma subcutaneous and intravenous/metastatic models as aggressive tumor models. The injection of the 78Fc-PLGA-SHK NPs to the MS1-xenograft mice resulted in significantly higher accumulation and effects in the TEM1-positive tumor targets, while they were excreted via urine track without retaining in the liver/spleen. In the TC1 subcutaneous model, C57/BL6 mice treated with the 78Fc-PLGA-SHK NPs revealed a significant therapeutic effect. The mice, which were tumor-free after receiving the nanoformulation, were re-challenged with the TC1 cells to investigate the immune response. These animals became tumor-free a week after the injection of TC1 cells. Conclusion: Based on these findings, we propose the 78Fc-PLGA-SHK NPs as a highly effective immunostimulating nanomedicine against the TEM1-expressing cells for targeted therapy of solid tumors including ovarian cancer.

Inhibition of VEGFA Increases the Sensitivity of Ovarian Cancer Cells to Chemotherapy by Suppressing VEGFA-Mediated Autophagy

Background

Ovarian cancer (OvCa) is the leading cause of death of gynecological malignancies worldwide. Vascular endothelial growth factor A (VEGFA), the most potent angiogenic factor, is responsible for tumor growth and angiogenesis, but its role in OvCa chemotherapy resistance remains unclear.

Methods

RT-PCR and Western blot were used to detect VEGFA expression in tumor cells and normal ovarian surface epithelial cells. Gene Ontology (GO) enrichment analysis was used to analyze GO terms correlated with VEGFA. In in vitro experiments, we knockdown VEGFA in tumor cells and detected the tumor cell viability and apoptosis after chemotherapy drug treatment by MTT assay and flow cytometry. Western blot was used to detect autophagy and apoptosis related proteins.

Results

We proved that VEGFA was highly expressed in tumor cells comparted with normal ovarian surface epithelial cells, and enriched GO analysis of VEGFA showed that VEGFA was involved in anti-apoptotic process. Further in vitro experiments confirmed that expression of VEGFA was correlated with chemotherapy resistance and this effect was mediated by autophagy. Meanwhile tumor cells treated with chemotherapy drugs also promoted the expression of VEGFA. Knockdown VEGFA inhibited autophagy of tumor cells and thus potents the killing efficiency in DDP resistant tumor cells and this effect could be reversed by the addition of recombinant VEGFA.

Conclusion

Taken together, our study demonstrates that VEGFA is involved in anti-apoptosis of tumor cells to chemotherapy, killing partly through autophagy, indicating that VEGFA may serve as a potential target to improve chemotherapy treatment.

Urinary symptoms in women receiving carboplatin/paclitaxel for treatment of gynecologic cancers

OBJECTIVES

Urinary incontinence is estimated to affect up to 34% of women with gynecologic cancers. Chemotherapeutic effects on urinary symptoms have been scarcely studied. The aim of our study was to examine the impact of carboplatin/paclitaxel chemotherapy on urinary symptoms.

METHODS

This was a prospective cohort study of all women undergoing adjuvant chemotherapy with carboplatin/paclitaxel after their primary debulking surgery for ovarian, fallopian tube, peritoneal, or endometrial cancers performed at a tertiary medical center by board certified gynecologic oncologists. We used validated questionnaires (incontinence impact questionnaire (IIQ-7), medical, epidemiologic, and social aspects of aging (MESA), urogenital distress inventory (UDI-6), the Sandvik severity index, and functional assessment of cancer therapy/GynecologicOncology Group-neurotoxicity (FACT/GOG-Ntx)) to assess the effects of carboplatin/paclitaxel therapy on the incidence and severity of urinary incontinence at three time points during the participants' chemotherapy regimen: start of chemotherapy (pretreatment), during the fifth chemotherapy cycle (mid-cycle), and during the 6-12 week post-chemotherapy visit (post-treatment).

RESULTS

We identified 62 women with ovarian, fallopian, peritoneal, and endometrial cancer who received carboplatin/paclitaxel therapy between May 2009 and December 2012 who met all of the inclusion criteria. Analysis of median IIQ-7 scores, across all time points, showed a statistically significant difference (0.0 (0.0 to 4.8), 0.0 (0.0 to 7.1), 0.0 (0.0 to 0.0), p=0.002, respectively). Examining pairwise differences between two treatment points, IIQ-7 pretreatment versus mid-treatment and pretreatment versus post-treatment, did not achieve significance (0.0 (0.0 to 2.4), p=0.13 and 0.0 (0.0 to 0.0), p>0.999, respectively), but the decrease in IIQ-7 mid-treatment versus post-treatment was statistically significant (0.0 (-2.4 to 0.0), p=0.003). Generalized estimating equation model analysis also showed significant changes in both median MESA for urge urinary incontinence (MESA-UUI) and median MESA for stress urinary incontinence (MESA-SUI) across all time points (p=0.003 and p=0.009, respectively). MESA-UUI and MESA-SUI pretreatment versus mid-treatment analysis achieved significance (2.0 (0.0 to 4.0), p=0.003 and 0.0 (0.0 to 2.0), p=0.01, respectively), demonstrating an increase in the incidence of stress urinary incontinence and urge urinary incontinence. There was a statistically significant association between the changes in FACT and UDI-6 scores from pretreatment versus mid-treatment, with a correlation coefficient of 0.37 (95% CI 0.08 to 0.61, p=0.005).

CONCLUSION

The study achieved its primary aim in demonstrating an impact of carboplatin/paclitaxel therapy on urinary incontinence severity and suggests if may be a factor leading to new onset or worsening urinary incontinence. As quality of life can be significantly impacted by these chemotherapeutic changes, further investigation is warranted to determine if the effects on urinary incontinence and neuropathy are transient or permanent.

Synergistic enhancement of efficacy of platinum drugs with verteporfin in ovarian cancer cells

Background

Epithelial ovarian cancers (EOCs) comprises the majority of malignant ovarian neoplasms. Combination treatment with chemotherapeutic agents seems to be a promising strategy in ovarian cancer (OVCA) patients in order to overcome drug resistance. In this in vitro study, we investigated the therapeutic efficacy of verteporfin (VP) alone and in combination with cisplatin (CDDP), carboplatin (CP) and paclitaxel (Taxol). The main objectives of this study are to determine the nature of interactions between VP and CDDP/CP/Taxol and to understand the mechanism of action of VP in OVCA cells.

Methods

The efficacy of VP on cell proliferation, cytotoxicity, invasion and clonogenic capacity was assayed in CDDP-sensitive (COV504, OV-90) and CDDP-resistant (A2780Cis) cell lines. The cytotoxic effects of drugs either alone or in combination were evaluated using MTT assay and Cell Viability Blue assay. The effects of drugs on the metabolic functions were studied using matrigel invasion assay and clonogenic assay. Immunoblot analysis was carried out to investigate changes in YAP and cell cycle genes. Changes in the cytokines due to drug treatments were analyzed using a cytokine array.

Results

Treatment with VP inhibited cell proliferation, invasion and increased cytotoxicity of OVCA cells. We observed that VP chemosensitized CDDP-resistant cells, even at lower doses. When added either in constant or non-constant ratios, VP produced synergistic effects in combination with CDDP/CP/Taxol. A cytokine array identified upregulation of cytokines in OVCA cells that were inhibited by VP treatment.

Conclusions

Either in cisplatin-resistant cell lines or cisplatin-sensitive cell lines, VP proves to be more efficient in inhibiting cell proliferation and inducing cytotoxicity. Our results suggest that novel combinations of VP with CDDP or CP or Taxol might be an attractive therapeutic strategy to enhance OVCA chemosensitivity. The fact that lower doses of VP are effective in chemosensitizing the CDDP-resistant cells, might ultimately lead to the development of an innovative combination therapy for the treatment of OVCA patients.

Comparing Paclitaxel-Carboplatin with Paclitaxel-Cisplatin as the Front-Line Chemotherapy for Patients with FIGO IIIC Serous-Type Tubo-Ovarian Cancer

The use of weekly chemotherapy for the treatment of patients with advanced-stage serous-type epithelial Tubo-ovarian cancer (ETOC), and primary peritoneal serous carcinoma (PPSC) is acceptable as the front-line postoperative chemotherapy after primary cytoreductive surgery (PCS). The main component of dose-dense chemotherapy is weekly paclitaxel (80 mg/m²), but it would be interesting to know what is the difference between combination of triweekly cisplatin (20 mg/m²) or triweekly carboplatin (carboplatin area under the curve 5-7 mg/mL per min [AUC 5-7]) in the dose-dense paclitaxel regimen. Therefore, we compared the outcomes of women with Gynecology and Obstetrics (FIGO) stage IIIC ETOC and PPSC treated with PCS and a subsequent combination of dose-dense weekly paclitaxel and triweekly cisplatin (paclitaxel–cisplatin) or triweekly carboplatin using AUC 5 (paclitaxel–carboplatin). Between January 2010 and December 2016, 40 women with International Federation of Gynecology and Obstetrics (FIGO) stage IIIC EOC, FTC, or PPSC were enrolled, including 18 treated with paclitaxel–cisplatin and the remaining 22 treated with paclitaxel–carboplatin. There were no statistically significant differences in disease characteristics of patients between two groups. Outcomes in paclitaxel–cisplatin group seemed to be little better than those in paclitaxel–carboplatin (median progression-free survival [PFS] 30 versus 25 months as well as median overall survival [OS] 58.5 versus 55.0 months); however, neither reached a statistically significant difference. In terms of adverse events (AEs), patients in paclitaxel–carboplatin group had more AEs, with a higher risk of neutropenia and grade 3/4 neutropenia, and the need for a longer period to complete the front-line chemotherapy, and the latter was associated with worse outcome for patients. We found that a period between the first-time chemotherapy to the last dose (6 cycles) of chemotherapy >21 weeks was associated with a worse prognosis in patients compared to that ≤21 weeks, with hazard ratio (HR) of 81.24 for PFS and 9.57 for OS. As predicted, suboptimal debulking surgery (>1 cm) also contributed to a worse outcome than optimal debulking surgery (≤1 cm) with HR of 14.38 for PFS and 11.83 for OS. Based on the aforementioned findings, both regimens were feasible and effective, but maximal efforts should be made to achieve optimal debulking surgery and following the on-schedule administration of dose-dense weekly paclitaxel plus triweekly platinum compounds. Randomized trials validating the findings are warranted.

Chemotherapy Resistance in Advanced Ovarian Cancer Patients

Ovarian cancer is the seventh most common gynaecologic malignancy seen in women. Majority of the patients with ovarian cancer are diagnosed at the advanced stage making prognosis poor. The standard management of advanced ovarian cancer includes tumour debulking surgery followed by chemotherapy. Various types of chemotherapeutic regimens have been used to treat advanced ovarian cancer, but the most promising and the currently used standard first-line treatment is carboplatin and paclitaxel. Despite improved clinical response and survival to this combination of chemotherapy, numerous patients either undergo relapse or succumb to the disease as a result of chemotherapy resistance. To understand this phenomenon at a cellular level, various macromolecules such as DNA, messenger RNA and proteins have been developed as biomarkers for chemotherapy response. This review comprehensively summarizes the problem that pertains to chemotherapy resistance in advanced ovarian cancer and provides a good overview of the various biomarkers that have been developed in this field.

Downregulation of BAG3 attenuates cisplatin resistance by inhibiting autophagy in human epithelial ovarian cancer cells

Epithelial ovarian cancer (EOC) is one of the most common malignant gynecological tumors. Interval cytoreductive surgery and cisplatin-based chemotherapy are the standard treatments. However, acquired resistance to cisplatin presents a major challenge for improving the overall survival and prognosis of patients. Recent evidence indicates that cytoprotective functions of autophagy in cancer cells is a potential mechanism for chemoresistance. The present study aimed to investigate the mechanisms responsible for cisplatin resistance in EOC cell lines. The results revealed that cisplatin activated autophagy, measured by an increase in the expression of LC3-II by western blot analysis, protecting ovarian cancer cells from cisplatin toxicity. The present study also identified Bcl-2-associated athanogene 3 (BAG3) as a novel autophagy regulator that serves a role in cisplatin resistance. Treatment with cisplatin was observed to enhance BAG3 expression in parental and cisplatin-resistant ovarian cancer cell lines, and the downregulation of BAG3 blocked cisplatin-induced autophagy, thereby increasing cisplatin sensitivity in the EOC cell lines. In conclusion, BAG3 attenuates cisplatin resistance by inhibiting autophagy, suggesting that downregulation of BAG3 may be a useful therapeutic strategy to overcome cisplatin resistance by preventing cytoprotective autophagy in EOC.

Joint exposure to smoking, excessive weight, and physical inactivity and survival of ovarian cancer patients, evidence from the Ovarian Cancer Association Consortium

PURPOSE

Previous epidemiologic studies have shown that smoking, obesity, and physical inactivity are associated with poor survival following a diagnosis of ovarian cancer. Yet, the combined relationship of these unfavorable lifestyle factors on ovarian cancer survival has not been sufficiently investigated.

METHODS

Using data pooled from 13 studies, we examined the associations between combined exposures to smoking, overweight/obesity weight, and physical inactivity and overall survival (OS) as well as progression-free survival (PFS) among women diagnosed with invasive epithelial ovarian carcinoma (n = 7,022). Using age- and stage-adjusted Cox proportional hazards regression models, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with joint exposure to these factors.

RESULTS

Combined exposure to current smoking, overweight/obesity, and physical inactivity prior to diagnosis was associated with a significantly increased risk of mortality compared to women who never smoked, had normal body mass index (BMI), and were physically active (HR = 1.37; 95% CI 1.10-1.70). The association for a joint exposure to these factors exceeded that of each exposure individually. In fact, exposure to both current smoking and overweight/obesity, and current smoking and physical inactivity was also associated with increased risk of death (HR = 1.28; 95% CI 1.08-1.52, and HR = 1.26; 95% CI 1.04-1.54, respectively). The associations were of a similar magnitude when former smoking was assessed in combination with the other exposures and when excessive weight was limited to obesity only. No significant associations were observed between joint exposure to any of these factors and PFS.

CONCLUSIONS

Joint exposure to smoking, excessive weight, and physical inactivity may negatively impact survival of ovarian cancer patients. These results suggest the importance of examining the combined effect of lifestyle factors on ovarian cancer patients' survival.

MicroRNA let‑7d‑5p rescues ovarian cancer cell apoptosis and restores chemosensitivity by regulating the p53 signaling pathway via HMGA1

Ovarian cancer (OC) is the gynecological malignancy type with the highest mortality rate in females. The regulatory effect of microRNAs (miRs) on their target genes serves a key role in tumor development. Therefore, in the present study, whether miR let‑7d‑5p targeting high mobility group A1 (HMGA1) regulated biological characteristics and chemosensitivity of OC cells by mediating the p53 signaling pathway was investigated. The let‑7d‑5p level was detected in OC tissues and adjacent normal tissues, followed by detection in OC cell lines SKOV3, A2780, OVCAR‑3 and CaOV3, and human normal ovarian epithelial cell line (IOSE‑80), in order to select the OC cell line for the following experiments. Subsequently, OC cells were treated with the let‑7d‑5p mimic, siHMGA1 and Tenovin‑1. The targeting association between let‑7d‑5p and HMGA1 was then examined, and the OC cell viability, migration, cycle and apoptosis were evaluated. Subsequently, the chemosensitivity of OC cells to cisplatin was verified. Finally, expression levels of let‑7d‑5p, HMGA1, p21, B‑cell lymphoma‑2 (Bcl‑2)‑associated X (Bax), p27, p53 wild‑type (p53wt), p53 mutated (p53mut), proliferating cell nuclear antigen (PCNA), cyclin‑dependent kinase 2 (CDK2), matrix metallopeptidase (MMP)2, MMP9 and Bcl‑2 were determined. As demonstrated in the results, let‑7d‑5p expression was low in OC tissues and had an increased reduction in the OVCAR‑3 cell line. HMGA1 was confirmed as a target of let‑7d‑5p, and its expression was also silenced by let‑7d‑5p. let‑7d‑5p repressed OC cell viability, migration, cell cycle progression and apoptosis, while it promoted the chemosensitivity of OC cells to cisplatin by targeting HMGA1. The expression of let‑7d‑5p, p21, Bax, p27 and p53wt was increased, while that of HMGA1, p53mut, PCNA, CDK2, MMP2, MMP9 and Bcl‑2 was reduced following cell transfection. The results in the present study provided evidence that let‑7d‑5p may suppress proliferation, and facilitate apoptosis and cisplatin chemosensitivity of OC cells by silencing HMGA1 via the p53 signaling pathway.

Tumor evolution and chemoresistance in ovarian cancer

Development of novel strategies to overcome chemoresistance is central goal in ovarian cancer research. Natural history of the cancer development and progression is being reconstructed by genomic datasets to understand the evolutionary pattern and direction. Recent studies suggest that intra-tumor heterogeneity (ITH) is the main cause of treatment failure by chemoresistance in many types of cancers including ovarian cancer. ITH increases the fitness of tumor to adapt to incompatible microenvironment. Understanding ITH in relation to the evolutionary pattern may result in the development of the innovative approach based on individual variability in the genetic, environment, and life style. Thus, we can reach the new big stage conquering the cancer. In this review, we will discuss the recent advances in understanding ovarian cancer biology through the use of next generation sequencing (NGS) and highlight areas of recent progress to improve precision medicine in ovarian cancer.

Perioperative epidural use and survival outcomes in patients undergoing primary debulking surgery for advanced ovarian cancer

OBJECTIVE

Epidurals are associated with improved outcomes in some solid tumors, presumably due to their effect on surgical stress response. There are limited data on the prognostic significance of epidural anesthesia in patients undergoing primary debulking surgery (PDS) for advanced ovarian cancer. We sought to assess the impact of epidural anesthesia on the survival outcomes of patients undergoing PDS for advanced ovarian cancer.

METHODS

In this retrospective study, consecutive patients with stage IIIB-IV epithelial ovarian, fallopian tube, or peritoneal carcinoma who underwent PDS at our institution from 01/2005-12/2013 were identified. Progression-free survival (PFS) and overall survival (OS) with regard to epidural use were analyzed.

RESULTS

Of 648 patients, 435 received an epidural and 213 did not. Patients in the former group were more likely to have higher stage disease (stage IV disease, 26% vs. 16%, respectively; P = .005), carcinomatosis (87% vs. 80%, respectively; P = .027), and bulky upper abdominal disease (66% vs. 58%, respectively; P = .046). Complete gross resection was achieved in 48% and 32%, respectively (P < .001). For the epidural vs. non-epidural groups, median PFS was 20.8 months and 13.9 months, respectively (P = .021); median OS was 62.4 months and 41.9 months, respectively (P < .001). After controlling for confounding factors, including residual disease, epidural use was independently associated with a decreased risk of progression (HR = 1.327; 95% CI, 1.066-1.653) and death (HR = 1.588; 95% CI, 1.224-2.06).

CONCLUSIONS

Perioperative epidural use was independently associated with improved PFS and OS in these patients. Epidural anesthesia at the time of PDS may be warranted in this setting.

Potential for Mitochondrial DNA Sequencing in the Differential Diagnosis of Gynaecological Malignancies

In the event of multiple synchronous gynecological lesions, a fundamental piece of information to determine patient management, prognosis, and therapeutic regimen choice is whether the simultaneous malignancies arise independently or as a result of metastatic dissemination. An example of synchronous primary tumors of the female genital tract most frequently described are ovarian and endometrial cancers. Surgical findings and histopathological examination aimed at resolving this conundrum may be aided by molecular analyses, although they are too often inconclusive. High mitochondrial DNA (mtDNA) variability and its propensity to accumulate mutations has been proposed by our group as a tool to define clonality. We showed mtDNA sequencing to be informative in synchronous primary ovarian and endometrial cancer, detecting tumor-specific mutations in both lesions, ruling out independence of the two neoplasms, and indicating clonality. Furthermore, we tested this method in another frequent simultaneously detected gynecological lesion type, borderline ovarian cancer and their peritoneal implants, which may be monoclonal extra-ovarian metastases or polyclonal independent masses. The purpose of this review is to provide an update on the potential use of mtDNA sequencing in distinguishing independent and metastatic lesions in gynecological cancers, and to compare the efficiency of molecular analyses currently in use with this novel method.

Tanshinone IIA effects on ovarian cancer cell line

OBJECTIVES

To explore the potential therapeutic effect of Tanshinone IIA against ovarian cancer in vitro and elucidate the underlying molecular mechanism.

METHODS

The cell survival upon Tanshinone IIA treatment was determined by the clonogenic assay. Cell apoptosis was analysed by Annexin V/propidium iodide double staining. The cleaved caspase-3/poly ADP-ribose polymerase and apoptosis-related factors were quantified by Western blotting. The relative expression of microRNAs (miRs) was determined by real-time polymerase chain reaction.

KEY FINDINGS

Tanshinone IIA treatment induced significant apoptosis in TOV-21G cells. Tanshinone suppressed survivin expression while not affected Bax, Bcl-2 and Bcl-xL. We further predicted and experimentally confirmed overexpression of miR-205 in TOV-21G, which ectopic significantly inhibited survivin and promoted cell apoptosis. miR-205-specific antagonist completely abrogated the cell suppressive effect of Tanshinone IIA.

CONCLUSIONS

Our data suggested that Tanshinone IIA induced cell apoptosis in ovarian carcinoma TOV-21G cells via direct upregulation of miR-205. Our study highlighted the potential therapeutic application of Tanshinone IIA against ovarian malignancy.

Addition of intraperitoneal cisplatin and etoposide to first-line chemotherapy for advanced ovarian cancer: a randomised, phase 2 trial

BACKGROUND

We assessed the efficacy of adding intraperitoneal (IP) chemotherapy to standard first-line intravenous (IV) chemotherapy in epithelial ovarian cancer (EOC) patients.

METHODS

Patients with stage IIIC-IV EOC who underwent optimal debulking surgery were randomly assigned to four cycles of weekly IP chemotherapy with cisplatin (50 mg/m²) and etoposide (100 mg/m²) followed by six cycles of IV chemotherapy every 3 weeks (IP/IV arm), or were administered IV chemotherapy alone (IV arm). The primary endpoint for this study was the 12-month non-progression rate (NPR).

RESULTS

Between 4/2009 and 9/2015, 218 patients were randomised, of whom 215 initiated treatment. In the IP/IV arm, 90.6% of patients completed 4 cycles of IP chemotherapy. The 12-month NPRs were 81.9% and 64.2% in the IP/IV and IV groups, respectively (HR 0.48 (95% CI 0.27-0.82)). The median progression-free survival (PFS) was increased in the IP/IV arm compared with that in the IV arm (22.4 vs. 16.8 months; HR 0.66 (0.48-0.91)) and in a subgroup with no gross cytoreduction (31.1 vs. 16.8 months; HR 0.46 (0.26-0.82)). Similar findings were detected with regard to time to first subsequent anticancer therapy (TFST) (25.9 vs. 18.0 months; P = 0.009) and time to second subsequent anticancer therapy (TSST) (40.8 vs. 30.1 months; P = 0.042). Grade 3/4 leukopenia, anaemia and gastrointestinal events were more common in the IP/IV arm, but the treatment burden was considered acceptable.

CONCLUSIONS

IP chemotherapy prior to IV chemotherapy was associated with an increased 12-month NPR and a longer TSST than IV alone in patients with EOC, albeit with acceptable toxic effects. Long-term follow-up is warranted to identify the effects of IP therapy on overall survival.

Synthetic paclitaxel-octreotide conjugate reversing the resistance of A2780/Taxol to paclitaxel in xenografted tumor in nude mice

Peptide hormone-based targeted therapy to tumors has been studied extensively. Our previous study shows that somatostatin receptor expresses high level on drug-resistant human ovarian cancer. The paclitaxel-octreotide conjugate (POC) exhibits enhanced growth inhibition, as well as reduced toxicity, in paclitaxel-resistant human ovarian cancer cells. The aim of this study was to investigate the effect of targeted cytotoxicity and potential reversal mechanism of resistance in paclitaxel-resistant human ovarian cancer cells xenografted into nude mice. The SSTR2 shows higher expression levels in tumor tissue. Moreover, fluorescein-labeled POC displays favorable targeting in tumor cells. POC presents the perfect efficacy in inhibiting tumor growth and exerts lower or no toxic effects on normal tissues. Real-time PCR and Western Blotting has demonstrated that the mRNA and protein expressions of SSTR2 in POC group were significantly higher, while MDR1, α-tubulin, βIII-tubulin, VEGF and MMP-9 were significantly lower than in the other treatment groups and controls. Combined with the previous study in vitro, this study evaluates an effective approach on the treatment of paclitaxel-resistant ovarian cancer which expresses somatostatin receptor SSTR. Our investigation has also revealed the possible molecular mechanism of POC in treating the ovarian cancer, and therefore, provided a theoretical basis for the clinical application of this newly-invented compound.

Anthropometric characteristics and ovarian cancer risk and survival

PURPOSE

Multiple studies have examined the role of anthropometric characteristics in ovarian cancer risk and survival; however, their results have been conflicting. We investigated the associations between weight change, height and height change and risk and outcome of ovarian cancer using data from a large population-based case-control study.

METHODS

Data from 699 ovarian cancer cases and 1,802 controls who participated in the HOPE study were included. We used unconditional logistic regression adjusted for age, race, number of pregnancies, use of oral contraceptives, and family history of breast or ovarian cancer to examine the associations between self-reported height and weight and height change with ovarian cancer risk. Cox proportional hazards regression models adjusted for age and stage were used to examine the association between the exposure variables and overall and progression-free survival among ovarian cancer cases.

RESULTS

We observed an increased risk of ovarian cancer mortality and progression for gaining more than 20 pounds between ages 18-30, HR 1.36; 95% CI 1.05-1.76, and HR 1.31; 95% CI 1.04-1.66, respectively. Losing weight and gaining it back multiple times was inversely associated with both ovarian cancer risk, OR 0.78; 95% CI 0.63-0.97 for 1-4 times and OR 0.73; 95% CI 0.54-0.99 for 5-9 times, and mortality, HR 0.63; 95% CI 0.40-0.99 for 10-14 times. Finally, being taller during adolescence and adulthood was associated with increased risk of mortality. Taller stature and weight gain over lifetime were not related to ovarian cancer risk.

CONCLUSIONS

Our results suggest that height and weight and their change over time may influence ovarian cancer risk and survival. These findings suggest that biological mechanisms underlying these associations may be hormone driven and may play an important role in relation to ovarian carcinogenesis and tumor progression.

In vitro study on reversal of ovarian cancer cell resistance to cisplatin by naringin via the nuclear factor-κB signaling pathway

The aim of the present study was to investigate the mechanism of action by which naringin reverses the resistance of ovarian cancer cells to cisplatin. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and western blotting assays were used to detect the effects of different concentrations of naringin on the expressions of nuclear factor (NF)-κB and P-glycoprotein (P-gp) in the SKOV3/CDDP cell line. Small interfering RNA (siRNA) targeting NF-κB was designed and synthesized to silence NF-κB, and recombinant plasmid vectors overexpressing NF-κB were constructed to transfect cells. RT-qPCR and western blotting assays were subsequently performed to detect the effects of NF-κB on the expression of P-gp at the mRNA and protein levels. Naringin was added to the NF-κB-overexpressing SKOV3/CDDP cells and cultured for 48 h, followed by the detection of the expression of P-gp. RT-PCR and western blotting results demonstrated that the gene and protein expressions of NF-κB and P-gp were significantly decreased in a dose-dependent manner by naringin treatment (P<0.05). In cells overexpressing NF-κB, P-gp expression was significantly elevated (P<0.05), and the expression of P-gp was significantly decreased when NF-κB was silenced (P<0.05). Treatment with naringin was able to significantly ameliorate the NF-κB-induced overexpression of P-gp (P<0.05). These results indicate that naringin is able to inhibit the expression of NF-κB and P-gp in SKOV3/CDDP cells. Such an inhibitory effect may increase gradually with concentration, and is associated with blockade of the NF-κB signaling pathway. This pathway may represent one of the mechanisms of action by which Naringin reverses resistance to platinum-based agents in ovarian cancer cells.

Knockdown of BRCA2 enhances cisplatin and cisplatin-induced autophagy in ovarian cancer cells

Clinical implications of the BRCA2 expression level on treatments of ovarian cancer are controversial. Here, we demonstrated that platinum-resistant cancer had a higher percentage of high BRCA2 level (87.5% vs 43.6%, P = 0.001), and that patients with a low BRCA2 level in cancer tissues had longer progression-free survival (with a median time of 28.0 vs 12.0 months, P < 0.001) and platinum-free duration (with a median time of 19.0 vs 5.0 months, P < 0.001) compared with those with a high BRCA2 level. In human ovarian cancer cell lines CAOV-3 and ES-2, cisplatin induced an upregulation of the RAD51 protein, which was inhibited after silencing BRCA2; silencing BRCA2 enhanced the action of cisplatin in vitro and in vivo Knockdown of BRCA2 promoted cisplatin-induced autophagy. Interestingly, the autophagy blocker chloroquine enhanced cisplatin in BRCA2-silenced cells accompanied by an increase in apoptotic cells, which did not occur in BRCA2-intact cells; chloroquine enhanced the efficacy of cisplatin against BRCA2-silenced CAOV-3 tumors in vivo, with an increase in LC3-II level in tumor tissues. Sensitization of cisplatin was also observed in BRCA2-silenced CAOV-3 cells after inhibiting ATG7, confirming that chloroquine modulated the sensitivity via the autophagy pathway. These data suggest that a low BRCA2 level can predict better platinum sensitivity and prognosis, and that the modulation of autophagy can be a chemosensitizer for certain cancers.

Exosomal DNMT1 mediates cisplatin resistance in ovarian cancer

Ovarian cancer is the most common malignancy in women. Owing to late syndromic presentation and lack of efficient early detection, most cases are diagnosed at advanced stages. Surgery and platinum-based chemotherapy are still the standard care currently. However, resistance invoked often compromises the clinical value of the latter. Expression of DNA methyltransferase 1 (DNMT1) was analysed by gene array. Protein was determined by immunoblotting. Exosome was isolated with commercial kit. Cell proliferation was measured by CCK8 method. Annexin V-PI double staining was performed for apoptosis evaluation. Xenograft model was established and administrated with exosome. Tumour growth and overall survival were monitored. We demonstrated the upregulation of DNMT1 in both tumour and derived cell line. DNMT1 transcripts were highly enriched in exosomes from conditioned medium of ovarian cells. Co-incubation with exosomes stimulated endogenous expression and rendered host cell the resistance to cytotoxicity of cisplatin. In vivo administration of DNMT1-containing exosomes exacerbated xenograft progression and reduced overall survival significantly. Moreover, treatment with exosome inhibitor GW4869 almost completely restored sensitivity in resistant cells. Our data elucidated an unappreciated mechanism of exosomal DNMT1 in cisplatin resistance in ovarian cancer, also indicating the potential of the combination of exosome inhibitor with cisplatin in resistant patients.

Lipid‐enveloped PLGA as a hybrid carrier for sustained delivering camptothecin in ovarian cancer

Camptothecin (CPT) is plant alkaloid exhibiting in a wide range of solid tumours. However, CPT was instability at physiological pH conditions, the lactone moieties easily hydrolysed makes systemic toxicity risky. Moreover, the water insolubility of CPT was obstructed in clinical development. The aim of the study was to utilise nontoxic and biodegradable poly(D,L‐lactic‐co‐glycolic acid) (PLGA) incorporated lipid as a hybrid nanoparticle (lipid‐PLGA NPs) for delivery of CPT. Lipid‐PLGA NPs were produced by a nano‐precipitation technique. The optimal formulation was presented that particles of which were 43 nm in diameter, with a polydispersity index of 0.3 which indicated a smaller and well‐distributed pattern. Moreover, a high capacity of ∼95% entrapment efficiency was achieved. An in vitro release study showed that non‐formulated CPT with a lag time of ∼0 h, demonstrated an obvious burst effect; in contrast, sustained released and a lag time delay were clearly observed in lipid‐PLGA NPs. The cytotoxicity study confirmed that human ovarian cancer cells (ES‐2) were inhibited by lipid‐PLGA NPs. CPT was successful entrapped in lipid‐PLGA NPs which achieved smaller size and well distribution. Lipid‐PLGA NPs resolve the water insolubility and produced a sustained, slow‐release pattern of CPT and controlled the cytotoxicity toward ES‐2.

Use of a highly parallel microfluidic flow cell array to determine therapeutic drug dose response curves

A high-throughput, microfluidic flow cell array (MFCA) system has been modified to enable drug screening against small-volume cell-, and tissue cultures. The MFCA is composed of a 3D channel network that simultaneously flows fluids through forty-eight 830 μm by 500 μm flow cells, which physically divide and fluidically seal an existing culture into multiple compartments when docked onto the surface of a cell or tissue culture dish. The modified system provides temperature (37 °C) and CO₂/pH level controls, while continuously flowing solutions (media or other liquid such as drug suspensions) over the cells/tissues. These assays were enhanced and validated using inverted microscopy and fluorescent staining techniques which also allow real time viability and toxicity assessments. This work presents the results of this new generation in vitro drug testing assay performed using this modified MFCA system. This setup allows the testing of 48 drug combinations on 48 different cell-, tissue specimen at once under flow conditions. All 48 flow cells were utilized to test 5 different concentrations of cisplatin (CDDP). CDDP solutions in various concentrations were continually flowed over cultured human ovarian cancer cells for 48 h. Viability assessments were performed using red-orange calcein and SYTOX ® Green nucleic acid stains. Cells were imaged at the beginning and end of the experiment (48 h). In order to compare and validate MFCAs suitability as drug screening assay, MTT assays were performed on cells. We found that both, MTT and MFCA assays generated dose-response curves with similar profiles. Innovative advantages of the MFCA system include the ability of handling smaller amounts of solutions compared to conventional and current state of the art drug screening and cell viability/toxicity methods. It also provides the ability to continually deliver fresh solution to the cell samples, while eliminating wastes that are produced. Based on our here reported findings MFCA may have a strong potential of providing a more physiological model than current state of the art static MTT assays.

Silencing of BAG3 promotes the sensitivity of ovarian cancer cells to cisplatin via inhibition of autophagy

Ovarian cancer is the most lethal disease among all gynecological malignancies. Interval cytoreductive surgery and cisplatin‑based chemotherapy are the recommended therapeutic strategies. However, acquired resistance to cisplatin remains a big challenge for the overall survival and prognosis in ovarian cancer. Complicated molecular mechanisms are involved in the process. At present, increasing evidence indicates that autophagy plays an important role in the prosurvival and resistance against chemotherapy. In the present study, as a novel autophagy regulator, BCL2‑associated athanogene 3 (BAG3) was investigated to study its role in cisplatin sensitivity in epithelial ovarian cancer. However, whether BAG3 participates in cisplatin sensitivity by inducing autophagy and the underlying mechanism in ovarian cancer cells remain to be clarified. Through the use of quantitative real-time PCR, western blot analysis, CCK-8 and immunofluorescence assays our data revealed that cisplatin-induced autophagy protected ovarian cancer cells from the toxicity of the drug and that this process was regulated by BAG3. Silencing of BAG3 increased cisplatin-induced apoptosis. The results also revealed BAG3 as a potential therapeutic target which enhanced the efficacy of cisplatin in ovarian cancer.

Inhibition of paclitaxel resistance and apoptosis induction by cucurbitacin B in ovarian carcinoma cells

Ovarian cancer is the leading cause of mortality among all gynecological malignancies. Drug resistance is a cause of ovarian cancer recurrence and low rate of overall survival. There is a requirement for more effective treatment approaches. Cucurbitacin B (CuB) is an antineoplastic agent derived from traditional Chinese medicinal herbs. Its activity against paclitaxel-resistant human ovarian cancer cells has, however, not yet been established. The purpose of the present study was to investigate the effect and mechanism of CuB on human paclitaxel-resistant ovarian cancer A2780/Taxol cells. Cell viability was evaluated by a cell counting assay, while cell cycle arrest and apoptosis were assessed by microscopy and flow cytometry, and proteins associated with apoptotic pathways and drug resistance were evaluated by western blotting. The present results demonstrated that CuB exerts dose- and time-dependent cytotoxicity against the ovarian cancer A2780 cell line, with half-maximal inhibitory concentration (IC₅₀) values 0.48, 0.25 and 0.21 µM following 24, 48 and 72 h of incubation, respectively. Compared with its sensitive counterpart, A2780, paclitaxel-resistant A2780/Taxol cells had almost identical IC₅₀ values. Cell cycle analysis demonstrated that treatment with CuB may induce cell cycle arrest at the G₂/M phase of the cell cycle in the two cell lines. As revealed by Annexin V/propidium iodide-labeled flow cytometry and Hoechst 33258 staining, CuB-induced apoptosis was accompanied by activation of caspase-3 and downregulation of B-cell lymphoma-2. Western blotting demonstrated that CuB may enhance the expression of p53 and p21 in the two cell lines. CuB may also downregulate the expression of P-glycoprotein. These results indicate that CuB may exert a therapeutic effect on paclitaxel-resistant human ovarian cancer.

Oleuropein represses the radiation resistance of ovarian cancer by inhibiting hypoxia and microRNA-299-targetted heparanase expression

Radiotherapy in ovarian cancer frequently invokes resistance; this severely compromises its therapeutic effect and results in poor clinical prognosis.

Emergent role of the fractalkine axis in dissemination of peritoneal metastasis from epithelial ovarian carcinoma

Epithelial ovarian carcinoma is the most common cause of death from gynecologic cancers largely due to advanced, relapsed, and chemotherapy-resistant peritoneal metastasis, which is refractory to the currently used treatment approaches. Mechanisms supporting advanced and relapsed peritoneal metastasis are largely unknown, precluding development of more effective targeted therapies. In this study we investigated the function of a potentially targetable fractalkine axis in the formation and the development of advanced and relapsed peritoneal metastasis and its impact on patients’ outcomes. Our mouse model studies support a role for the fractalkine receptor (CX₃CR1) in the initiation of peritoneal adhesion important for recolonization of relapsed peritoneal metastasis. We show that downregulation of CX₃CR1 results in reduction of metastatic burden at several peritoneal sites commonly colonized by advanced and relapsed metastatic ovarian carcinoma. We show that the chemokine fractalkine (CX₃CL1), an activating ligand of CX₃CR1, regulates organ-specific peritoneal colonization. High expression of CX₃CR1 correlates with significantly shorter survival, specifically in post-menopausal patients with advanced and terminal stages of the disease. Taken together, our studies support a key regulatory role for the fractalkine axis in advanced and relapsed peritoneal metastasis in epithelial ovarian carcinoma.

Dysregulation of Aromatase in Breast, Endometrial, and Ovarian Cancers: An Overview of Therapeutic Strategies

Aromatase is the rate-limiting enzyme in the biosynthesis of estrogens, which play crucial roles on a spectrum of developmental and physiological processes. The biological actions of estrogens are classically mediated by binding to two estrogen receptors (ERs), ERα and ERβ. Encoded by the cytochrome P450, family 19, subfamily A, polypeptide 1 (CYP19A1) gene, aromatase is expressed in a wide variety of tissues, as well as benign and malignant tumors, and is regulated in a pathway- and tissue-specific manner. Overexpression of aromatase, leading to elevated systemic levels of estrogen, is unequivocally linked to the pathogenesis and growth of a number malignancies, including breast, endometrium, and ovarian cancers. Aromatase inhibitors (AIs) are routinely used to treat estrogen-dependent breast cancers in postmenopausal women; however, their roles in endometrial and ovarian cancers remain obscure. While AI therapy is effective in hormone sensitive cancers, they diminish estrogen production throughout the body and, thus, generate undesirable side effects. Despite the effectiveness of AI therapy, resistance to endocrine therapy remains a major concern and is the leading cause of cancer death. Considerable advances, toward mitigating these issues, have evolved in conjunction with a number of histone deacetylase (HDAC) inhibitors for countering an assortment of diseases and cancers, including the aforesaid malignancies. HDACs are a family of enzymes that are frequently dysregulated in human tumors. This chapter will discuss the current understanding of aberrant regulation and expression of aromatase in breast, endometrial, and ovarian cancers, and potential therapeutic strategies for prevention and treatment of these life-threatening diseases.

Novel ABCG2 Antagonists Reverse Topotecan-Mediated Chemotherapeutic Resistance in Ovarian Carcinoma Xenografts

Chemotherapeutic resistance remains a challenge in the treatment of ovarian carcinoma, especially in recurrent disease. Despite the fact that most patients with newly diagnosed tumors attain complete remission following cytoreductive surgery and chemotherapy, ovarian carcinoma has a recurrence rate that exceeds 75%. The ATP-binding cassette family G member 2 (ABCG2) efflux protein has been described as one mechanism that confers multiple-drug resistance to solid tumors and contributes to topotecan resistance in ovarian carcinoma. In fact, one clinical trial demonstrated ABCG2 expression in all patients with primary or recurrent ovarian carcinoma. On the basis of our previous work, we hypothesized that three compounds (CID44640177, CID1434724, and CID46245505), which represent a new piperazine-substituted pyrazolo[1,5]pyrimidine substructure class of ABCG2-specific antagonists, would restore chemosensitivity to drug-resistant ovarian cancer in vitro and in vivo To address the treatment difficulties associated with chemotherapeutic resistance in ovarian cancer, we combined each compound (CID44640177, CID1434724, and CID46245505) with topotecan and administered the mixture to chemoresistant Igrov1/T8 ovarian cancer cells in vitro and Igrov1/T8 xenografts in CB-17 SCID mice. We found that only nanomolar concentrations of each ABCG2 inhibitor in combination with topotecan were required to restore chemosensitivity to Igrov1/T8 cells in vitro In vivo, substantial tumor reduction was achieved with each compound in 4 days, with CID1434724 causing the largest reduction in excess of 60%. No signs of secondary toxic effects were observed with the ABCG2 antagonists. These novel compounds should be viewed as promising drug candidates to reverse ABCG2-mediated chemoresistance. Mol Cancer Ther; 15(12); 2853-62. ©2016 AACR.

Downregulation of ATG14 by EGR1-MIR152 sensitizes ovarian cancer cells to cisplatin-induced apoptosis by inhibiting cyto-protective autophagy

Cisplatin is commonly used in ovarian cancer treatment by inducing apoptosis in cancer cells as a result of lethal DNA damage. However, the intrinsic and acquired resistance to cisplatin in cancer cells remains a big challenge for improving overall survival. The cyto-protective functions of autophagy in cancer cells have been suggested as a potential mechanism for chemoresistance. Here, we reported MIR152 as a new autophagy-regulating miRNA that plays a role in cisplatin-resistance. We showed that MIR152 expression was dramatically downregulated in the cisplatin-resistant cell lines A2780/CP70, SKOV3/DDP compared with their respective parental cells, and in ovarian cancer tissues associated with cisplatin-resistance. Overexpression of MIR152 sensitized cisplatin-resistant ovarian cancer cells by reducing cisplatin-induced autophagy, enhancing cisplatin-induced apoptosis and inhibition of cell proliferation. A mouse subcutaneous xenograft tumor model using A2780/CP70 cells with overexpressing MIR152 was established and displayed decreased tumor growth in response to cisplatin. We also identified that ATG14 is a functional target of MIR152 in regulating autophagy inhibition. Furthermore, we found that EGR1 (early growth response 1) regulated the MIR152 gene at the transcriptional level. Ectopic expression of EGR1 enhanced efficacy of chemotherapy in A2780/CP70 cells. More importantly, these findings were relevant to clinical cases. Both EGR1 and MIR152 expression levels were significantly lower in ovarian cancer tissues with high levels of ERCC1 (excision repair cross-complementation group 1), a marker for cisplatin-resistance. Collectively, these data provide insights into novel mechanisms for acquired cisplatin-resistance. Activation of EGR1 and MIR152 may be a useful therapeutic strategy to overcome cisplatin-resistance by preventing cyto-protective autophagy in ovarian cancer.

Novel high-grade serous epithelial ovarian cancer cell lines that reflect the molecular diversity of both the sporadic and hereditary disease

Few cell line models of epithelial ovarian cancer (EOC) have been developed for the high-grade serous (HGS) subtype, which is the most common and lethal form of gynaecological cancer. Here we describe the establishment of six new EOC cell lines spontaneously derived from HGS tumors (TOV2978G, TOV3041G and TOV3291G) or ascites (OV866(2), OV4453 and OV4485). Exome sequencing revealed somatic TP53 mutations in five of the cell lines. One cell line has a novel BRCA1 splice-site mutation, and another, a recurrent BRCA2 nonsense mutation, both of germline origin. The novel BRCA1 mutation induced abnormal splicing, mRNA instability, resulting in the absence of BRCA1 protein. None of the cell lines harbor mutations in KRAS or BRAF, which are characteristic of other EOC subtypes. SNP arrays showed that all of the cell lines exhibited structural chromosomal abnormalities, copy number alterations and regions of loss of heterozygosity, consistent with those described for HGS. Four cell lines were able to produce 3D-spheroids, two exhibited anchorage-independent growth, and three (including the BRCA1 and BRCA2 mutated cell lines) formed tumors in SCID mice. These novel HGS EOC cell lines and their detailed characterization provide new research tools for investigating the most common and lethal form of EOC.

Immunotherapy for ovarian cancer

OPINION STATEMENT

All work referenced herein relates to treatment of epithelial ovarian carcinomas, as their treatment differs from ovarian germ cell cancers and other rare ovarian cancers, the treatments of which are addressed elsewhere. Fallopian tube cancers and primary peritoneal adenocarcinomatosis are also generally treated as epithelial ovarian cancers. The standard of care initial treatment of advanced stage epithelial ovarian cancer is optimal debulking surgery as feasible plus chemotherapy with a platinum plus a taxane agent. If this front-line approach fails, as it too often the case, several FDA-approved agents are available for salvage therapy. However, because no second-line therapy for advanced-stage epithelial ovarian cancer is typically curative, we prefer referral to clinical trials as logistically feasible, even if it means referring patients outside our system. Immune therapy has a sound theoretical basis for treating carcinomas generally, and for treating ovarian cancer in particular. Advances in understanding the immunopathogenic basis of ovarian cancer, and the immunopathologic basis for prior failures of immunotherapy for it and other carcinomas promises to afford novel treatment approaches with potential for significant efficacy, and reduced toxicities compared with cytotoxic agents. Thus, referral to early phase immunotherapy trials for ovarian cancer patients that fail conventional treatment merits consideration.

Annexin A4 induces platinum resistance in a chloride-and calcium-dependent manner

Platinum resistance has long been a major issue in the treatment of various cancers. We previously reported that enhanced annexin A4 (ANXA4) expression, a Ca²⁺-regulated phospholipid-binding protein, induces chemoresistance to platinum-based drugs. In this study, we investigated the role of annexin repeats, a conserved structure of all the annexin family, responsible for platinum-resistance as well as the effect of knockdown of ANXA4. ANXA4 knockdown increased sensitivity to platinum-based drugs both in vitro and in vivo. To identify the domain responsible for chemoresistance, ANXA4 deletion mutants were constructed by deleting annexin repeats one by one from the C terminus. Platinum resistance was induced both in vitro and in vivo in cells expressing either full-length ANXA4 or the deletion mutants, containing at least one intact annexin repeat. However, cells expressing the mutant without any calcium-binding sites in the annexin repeated sequence, which is essential for ANXA4 translocation from the cytosol to plasma membrane, failed to acquire platinum resistance. After cisplatin treatment, the intracellular chloride ion concentration, whose channel is partly regulated by ANXA4, significantly increased in the platinum-resistant cells. These findings indicate that the calcium-binding site in the annexin repeat induces chemoresistance to the platinum-based drug by elevating the intracellular chloride concentration.

Rapamycin enhanced the antitumor efficacy of oxaliplatin in cisplatin-resistant ovarian cancer cells A2780cis both in vitro and in vivo

OBJECTIVE

This study aimed to investigate the efficacy of combination of rapamycin, an mammalian target of rapamycin (mTOR) inhibitor for treating rejection after organ transplantation, and oxaliplatin, a third-generation of platinum drug usually used to treat chemoresistant or progressive ovarian cancer, in cisplatin-resistant ovarian carcinoma cells A2780cis.

METHODS/MATERIALS

Expressions of mTOR and its target molecules p70S6K and 4E-BP1 were determined in cisplatin-sensitive and -resistant cells A2780 and A2780cis, respectively, using Western blotting. Proliferation of A2780cis exposure to oxaliplatin or oxaliplatin plus rapamycin was examined using MTT assay in vitro as well as a nude mice model in vivo. Cell apoptosis and proapoptosis proteins including caspase-8 and -3 and PARP were determined using flow cytometry and Western blotting.

RESULTS

We found that A2780cis cells had partial cross-resistance between cisplatin and oxaliplatin. The levels of phosphorylated mTOR (p-mTOR), p70S6K, and 4E-BP1 were significantly increased in A2780cis cells compared to A2780 cells, which might be implicated in cisplatin-induced chemoresistance. Rapamycin obviously enhanced the inhibitory effect of oxaliplatin on the growth of A2780cis both in vitro and in vivo. Rapamycin slightly induced cell apoptosis but significantly enhanced the effect of oxaliplatin in soliciting apoptosis of A2780cis cells, which might be ascribed to its ability in further increasing the levels of cleaved caspase-8 and -3 and PARP induced by oxaliplatin.

CONCLUSION

These results suggested that combination of oxaliplatin and rapamycin enhanced the antitumour efficacy of oxaliplatin in A2780cis cells and therefore might have a role in treating cisplatin-resistant ovarian carcinoma.

PG545 enhances anti-cancer activity of chemotherapy in ovarian models and increases surrogate biomarkers such as VEGF in preclinical and clinical plasma samples

BACKGROUND

Despite the utility of antiangiogenic drugs in ovarian cancer, efficacy remains limited due to resistance linked to alternate angiogenic pathways and metastasis. Therefore, we investigated PG545, an anti-angiogenic and anti-metastatic agent which is currently in Phase I clinical trials, using preclinical models of ovarian cancer.

METHODS

PG545's anti-cancer activity was investigated in vitro and in vivo as a single agent, and in combination with paclitaxel, cisplatin or carboplatin using various ovarian cancer cell lines and tumour models.

RESULTS

PG545, alone, or in combination with chemotherapeutics, inhibited proliferation of ovarian cancer cells, demonstrating synergy with paclitaxel in A2780 cells. PG545 inhibited growth factor-mediated cell migration and reduced HB-EGF-induced phosphorylation of ERK, AKT and EGFR in vitro and significantly reduced tumour burden which was enhanced when combined with paclitaxel in an A2780 model or carboplatin in a SKOV-3 model. Moreover, in the immunocompetent ID8 model, PG545 also significantly reduced ascites in vivo. In the A2780 maintenance model, PG545 initiated with, and following paclitaxel and cisplatin treatment, significantly improved overall survival. PG545 increased plasma VEGF levels (and other targets) in preclinical models and in a small cohort of advanced cancer patients which might represent a potential biomarker of response.

CONCLUSION

Our results support clinical testing of PG545, particularly in combination with paclitaxel, as a novel therapeutic strategy for ovarian cancer.

Frequent Loss of NISCH Promotes Tumor Proliferation and Invasion in Ovarian Cancer via Inhibiting the FAK Signal Pathway

NISCH encodes the imidazoline receptor Nischarin and is a known tumor suppressor in many human malignancies; however, its roles in ovarian cancer are still largely unknown. Here, we aim to investigate the biologic functions of NISCH in ovarian cancer. We found that NISCH was significantly downregulated, which correlated considerably with advanced tumor stage, poor differentiation, lymph node metastasis, and the serous/mucinous subtypes in a panel of ovarian cancer tissues. Moreover, NISCH gene silencing was mainly the product of promoter hypermethylation, which could be reversed by treatment with 5-aza-dC. In vitro, NISCH overexpression suppressed cell proliferation and colony formation by hindering cell-cycle progression, whereas the opposite was observed in NISCH knockdown counterparts. In vivo, abundant NISCH expression hindered the growth of HO8910 xenografts, whereas NISCH knockdown accelerated the growth of SKOV3 xenografts. In addition, NISCH significantly attenuated cell invasion by inhibiting the phosphorylation of FAK and ERK, which could be neutralized by PF-562271 (a FAK/Pyk2 inhibitor). Accordingly, NISCH knockdown xenografts exhibited increased peritoneal/pelvic metastases that were not present in counterparts treated with PF-562271. Furthermore, NISCH expression in primary ovarian cancer cells predicted a cellular resistance to PF-562271. In conclusion, we showed that NISCH was frequently silenced by promoter hypermethylation in human ovarian cancer. NISCH manipulated cellular proliferation and invasion by arresting cell cycle and inhibiting the FAK signal. Our findings revealed the biologic functions of NISCH in ovarian cancer, and might be useful for treating patients with aberrant expression of NISCH.

Three-dimensional collagen type I matrix up-regulates nuclear isoforms of the microtubule associated protein tau implicated in resistance to paclitaxel therapy in ovarian carcinoma

Epithelial ovarian carcinoma is the deadliest gynecologic malignancy. One reason underlying treatment failure is resistance to paclitaxel. Expression of the microtubule associated protein tau has recently been proposed as a predictor of response to paclitaxel in ovarian carcinoma patients. Expression of tau was probed using immunohistochemistry in 312 specimens of primary, and 40 specimens of metastatic, ovarian carcinoma. Serous epithelial ovarian carcinoma cell line models were used to determine the expression of tau by Western blot and immunofluorescence staining. Subcellular fractionation and Western blot were employed to examine nuclear and cytoplasmic localization of tau. Gene silencing and clonogenic assays were used to evaluate paclitaxel response. Tau was expressed in 44% of all tested cases. Among the primary serous epithelial ovarian carcinoma cases, 46% were tau-positive. Among the metastatic serous epithelial ovarian carcinomas, 63% were tau-positive. Cell culture experiments demonstrated that tau was expressed in multiple isoforms. Three-dimensional collagen I matrix culture conditions resulted in up-regulation of tau protein. Silencing of tau with specific siRNAs in a combination with three-dimensional culture conditions led to a significant decrease of the clonogenic ability of cells treated with paclitaxel. The data suggest that reduction of tau expression may sensitize ovarian carcinoma to the paclitaxel treatment.

Mitochondrial DNA genotyping efficiently reveals clonality of synchronous endometrial and ovarian cancers

Simultaneous independent primary tumors of the female genital tract occur in 1-2% of gynecological cancer patients, 50-70% of which are synchronous tumors of the endometrium and ovary. Recognition of synchrony upon multiple tumors is crucial for correct prognosis, therapeutic choice, and patient management. Current guidelines for determining synchrony, based on surgical and histopathological findings, are often ambiguous and may require further molecular analyses. However, because of the uniqueness of each tumor and of its intrinsic heterogeneity, these analyses may sometimes be inconclusive. A role for mitochondrial DNA genotyping was previously demonstrated in the diagnosis of synchronous endometrial and ovarian carcinoma. We have analyzed 11 sample pairs of simultaneously revealed endometrial and ovarian cancers and have thereby applied conventional histopathological criteria, current molecular analyses (microsatellite instability, β-catenin immunohistochemical staining/CTNNB1 mutation screening), and mitochondrial DNA sequencing to distinguish separate independent tumors from metastases, comparing the performance and the informative potential of such methods. We have demonstrated that in ambiguous interpretations where histopathological criteria and canonical molecular methods fail to be conclusive, mitochondrial DNA analysis may act as a needle of balance and allow to formulate a diagnosis in 45.5% of our cases. Additional advantages of mitochondrial DNA genotyping, besides the high level of information we demonstrated here, are the easy implementation and the need for small amounts of starting material. Our results show that mitochondrial DNA genotyping may provide a substantial contribution to indisputably recognize the metastatic nature of simultaneously detected endometrial and ovarian cancers and may change the final staging and clinical management of these patients.

Prognostic role of bowel involvement in optimally cytoreduced advanced ovarian cancer: a retrospective study

Background

Optimal debulking surgery is postulated to be useful in survival of ovarian cancer patients. Some studies highlighted the possible role of bowel surgery in this topic. We wanted to evaluate the role of bowel involvement in patients with advanced epithelial ovarian cancer who underwent optimal cytoreduction.

Methods

Between 1997 and 2004, 301 patients with advanced epithelial cancer underwent surgery at Department of Gynecological Oncology of Centro di Riferimento Oncologico (CRO) National Cancer Institute Aviano (PN) Italy. All underwent maximal surgical effort, including bowel and upper abdominal procedure, in order to achieve optimal debulking (R < 0.5 cm). PFS and OS were compared with residual disease, grading and surgical procedures.

Results

Optimal cytoreduction was achieved in 244 patients (81.0%); R0 in 209 women (69.4.%) and R < 0.5 in 35 (11.6%). Bowel resection was performed in 116 patients (38.5%): recto-sigmoidectomy alone (69.8%), upper bowel resection only (14.7%) and both recto-sigmoidectomy and other bowel resection (15.5%). Pelvic peritonectomy and upper abdomen procedures were carried out in 202 (67.1%) and 82 (27.2%) patients respectively. Among the 284 patients available for follow-up, PFS and OS were significantly better in patients with R < 0.5. Among the 229 patients with optimal debulking (R < 0.5), 137 patients (59.8%) developed recurrent disease or progression. In the 229 R < 0.5 group, bowel involvement was associated with decreased PFS and OS in G1-2 patients whereas in G3 patients OS, but not PFS, was adversely affected. In the 199 patients with R0, PFS and OS were significantly better (p < 0.01) for G1-2 patients without bowel involvement whereas only significant OS (p < 0.05) was observed in G3 patients without bowel involvement versus G3 patients with bowel involvement.

Conclusions

Optimal cytoreduction (R < 0.5 cm and R0) is the most important prognostic factor for advanced epithelial ovarian cancer. In the optimally cytoreduced (R < 0.5 and R0) patients, bowel involvement is associated with dismal prognosis for OS both in patients with G1-2 grading and in patients with G3 grading. Bowel involvement in G3 patients, carries instead the same risk of recurrence for PFS.

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.

Shikonin-loaded antibody-armed nanoparticles for targeted therapy of ovarian cancer

Conventional chemotherapy of ovarian cancer often fails because of initiation of drug resistance and/or side effects and trace of untouched remaining cancerous cells. This highlights an urgent need for advanced targeted therapies for effective remediation of the disease using a cytotoxic agent with immunomodulatory effects, such as shikonin (SHK). Based on preliminary experiments, we found SHK to be profoundly toxic in ovarian epithelial cancer cells (OVCAR-5 and ID8 cells) as well as in normal ovarian IOSE-398 cells, endothelial MS1 cells, and lymphocytes. To limit its cytotoxic impact solely to tumor cells within the tumor microenvironment (TME), we aimed to engineer SHK as polymeric nanoparticles (NPs) with targeting moiety toward tumor microvasculature. To this end, using single/double emulsion solvent evaporation/diffusion technique with sonication, we formulated biodegradable NPs of poly(lactic-co-glycolic acid) (PLGA) loaded with SHK. The surface of NPs was further decorated with solubilizing agent polyethylene glycol (PEG) and tumor endothelial marker 1 (TEM1)/endosialin-targeting antibody (Ab) through carbodiimide/N-hydroxysuccinimide chemistry. Having characterized the physicochemical and morphological properties of NPs, we studied their drug-release profiles using various kinetic models. The biological impact of NPs was also evaluated in tumor-associated endothelial MS1 cells, primary lymphocytes, and epithelial ovarian cancer OVCAR-5 cells. Based on particle size analysis and electron microscopy, the engineered NPs showed a smooth spherical shape with size range of 120 to 250 nm and zeta potential value of -30 to -40 mV. Drug entrapment efficiency was ~80%-90%, which was reduced to ~50%-60% upon surface decoration with PEG and Ab. The liberation of SHK from NPs showed a sustained-release profile that was best fitted with Wagner log-probability model. Fluorescence microscopy and flow cytometry analysis showed active interaction of Ab-armed NPs with TEM1-positive MS1 cells, but not with TEM1-negative MS1 cells. While exposure of the PEGylated NPs for 2 hours was not toxic to lymphocytes, long-term exposure of the Ab-armed and PEGylated NPs was significantly toxic to TEM1-positive MS1 cells and OVCAR-5 cells. Based on these findings, we propose SHK-loaded Ab-armed PEGylated PLGA NPs as a novel nanomedicine for targeted therapy of solid tumors.

Annexin A4 is a promising therapeutic target for the treatment of platinum-resistant cancers

INTRODUCTION

Platinum drugs are widely used for the treatment of testicular, bladder, ovarian, colorectal, lung and prostate cancers. With regard to ovarian cancer in particular, the prognosis is poor for tumours that are (or have become) platinum-resistant. Determining the mechanism underlying platinum resistance may aid in the identification of therapeutic targets for the treatment of platinum-resistant tumours.

AREAS COVERED

This review gives an overview of the characteristics and functions of Annexin (Anx) A4, the mechanism of Anx A4-induced platinum resistance, the association between platinum resistance and platinum transporters, recent reports that Anx A4 overexpression promotes the efflux of platinum drugs via platinum transporters and the association between other Anxs and chemoresistance. The reader will gain an understanding of recent studies on the mechanism of Anx A4-induced chemoresistance. Anx A4 represents a therapeutic target for the treatment of Anx A4-overexpressing platinum-resistant tumours.

EXPERT OPINION

Anx A4 is overexpressed in ovarian clear cell carcinoma (CCC), and enhanced Anx A4 expression induces platinum resistance. Recent studies showed that Anx A4 is also associated with platinum resistance in cancers other than ovarian CCC. Furthermore, other Anxs are reportedly associated with chemoresistance, suggesting a relationship between the Anx family and chemoresistance.