Past, present and future targets for immunotherapy in ovarian cancer

Overexpression FARSB Reveals Poor Prognosis in Breast Cancer and is Correlated with Immunity

BACKGROUND

FARSB is a β-regulatory subunit of phenylalanine tRNA synthetase. It is reported that FARSB was involved in cancer progression. However, the molecular function of FARSB in breast cancer was unclear. This study aimed to investigate the prognostic significance of FARSB expression and its relationship with immunity in breast cancer.

METHODS

Several databases, including TCGA, HPA, and UALCAN database, were applied to study FARSB mRNA and protein expression and its association with aggressiveness in breast cancer. We used immunohistochemical staining (IHC) to study FARSB expression in breast cancer and normal tissues. Chi square test was explored to study the correlation between FARSB expression and clinical features in breast cancer. Kaplan-Meier analysis and Cox regression were utilized to discuss the prognosis of breast cancer. Spearman analysis was applied to analyze the association between FARSB expression and immunity. We studied the correlation of FARSB with common breast cancer chemotherapeutic drugs. We conducted GO, KEGG, and GSEA enrichment analysis to study the molecular function of FARSB in breast cancer.

RESULTS

The TCGA database suggested that FARSB was increased in several cancers, including breast cancer. HPA and UALCAN databases suggested that FARSB protein expression was higher in breast cancer than normal tissues. IHC analysis also confirmed the higher expression of FARSB in breast cancer. FARSB expression had correlation with ER status and PR status. In TCGA database, FARSB expression was related to ER status, PR status, and PAM50. Overexpression FARSB had adverse prognosis, and Cox regression considered FARSB as a prognostic marker. Immunological analysis demonstrated that FARSB was linked with immune cell infiltration and immune checkpoints. High FARSB expression had low TIDE score. In addition, FARSB was linked to drugs, such as 5-fluorouracil, doxorubicin, gemcitabine, and paclitaxel. GSEA analysis suggested that FARSB was involved in the pathways, including cell cycle, aminoacyl TRNA biosynthesis, DNA replication, spliceosome, and mismatch repair.

CONCLUSION

FARSB was highly expression at mRNA and protein level in breast cancer. Overexpression of FARSB had a poor prognosis in breast cancer. FARSB expression was associated with immunity and acted as a new target for cancer immunological therapy.

Comprehensive systems biology analysis reveals splicing factor contributions to cutaneous melanoma progression

Cutaneous melanoma (CM) is an aggressive skin cancer with high metastatic potential and poor prognosis. Splicing factors, which regulate pre-mRNA alternative splicing (AS) events, have been suggested as potential therapeutic targets in CM. The objective of this study was to identify candidate splicing factors involved in CM through a systems biology approach and to elucidate their roles in CM progression. 390 AS events associated with patient survival were identified using bivariate Cox regression and receiver operating characteristic (ROC) analyses. 121 splicing factors significantly associated with patient prognosis were screened by univariate Cox regression analysis. A bipartite association network between AS events and splicing factors was constructed using Spearman correlation analysis. Based on the network topology, five candidate splice factors were identified. Among them, U2SURP, a poorly characterized serine/arginine-rich protein family member, was selected for further analysis in CM. Results indicated that U2SURP gene expression was significantly negatively correlated with the Immune Infiltration Score, the infiltration levels of dendritic cells, gamma-delta T cells, natural killer (NK) cells, and cytotoxic cells, as well as the expression of the immune checkpoint gene PD-1, suggesting that U2SURP may serve as a potential target for CM immunotherapy. Experimental validation showed that U2SURP mRNA and protein were overexpressed in CM cells, and silencing of U2SURP using siRNA significantly reduced CM cell survival, proliferation and migration. Furthermore, single-cell functional analysis showed that U2SURP gene expression was positively correlated with CM cell proliferation and differentiation. This study systematically identified candidate splicing factors involved in CM and provided new insights into the role of U2SURP in CM progression. These findings contribute to a deeper understanding of the pathogenesis of CM and establish new approaches for identifying splicing-related cancer therapeutic targets.

A pan-cancer analysis of homeobox family: expression characteristics and latent significance in prognosis and immune microenvironment

Background

The Homeobox (HOX) gene family are conserved transcription factors that are essential for embryonic development, oncogenesis, and cancer suppression in biological beings. Abnormally expressed HOX genes in cancers are directly associated with prognosis.

Methods

Public databases such as TCGA and the R language were used to perform pan-cancer analyses of the HOX family in terms of expression, prognosis, and immune microenvironment. The HOX score was defined, and potential target compounds in cancers were predicted by Connective Map. Immunohistochemistry was employed to validate protein expression levels. Gene knockdowns were used to verify the effects of HOXB7 and HOXC6 on the proliferation and migration of lung adenocarcinoma (LUAD) cells.

Results

HOX genes play different roles in different cancers. Many HOX genes, especially HOXB7 and HOXC6, have higher expression and lower overall survival in specific cancers and are predicted as risk factors. The high expression of most HOX genes is mainly related to immune subtypes C1-C4 and C6. Potential anti-tumor compounds for down-regulating HOX gene expression were identified, such as HDAC inhibitors and tubulin inhibitors. LUAD Cell migration and proliferation were inhibited when HOXB7 or HOXC6 was knocked down.

Conclusions

Many HOX genes may act as both oncogenes and tumor suppressor genes, necessitating precision medicine based on specific cancers. The HOX gene family plays a crucial role in the development of certain cancers, and their expression patterns are closely related to cancer prognosis and the tumor microenvironment (TME), which may affect cancer prognosis and response to immunotherapy. Compounds that are negatively correlated with the expression levels of the HOX family in various cancers, such as HDAC inhibitors, are potential anti-cancer drugs. HOXB7 and HOXC6 may serve as potential targets for cancer treatment and the development of targeted compounds in the future.

PARP Inhibitors Differentially Regulate Immune Responses in Distinct Genetic Backgrounds of High-Grade Serous Tubo-Ovarian Carcinoma

SIGNIFICANCE

This work highlights how different PARPis, especially talazoparib, modulate immune-related gene expression in ovarian cancer cells, independent of the cGAS-STING pathway. These findings may improve our understanding of how different PARPis affect the immune system in various genetic backgrounds.

Comprehensive Pan-Cancer Analysis and Functional Studies Reveal SLC2A6 as a Ferroptosis Modulator in Hepatocellular carcinoma

Soluble vector family member 6 (SLC2A6) has been implicated in the aggressiveness and poor prognosis of various cancers, yet its specific role in hepatocellular carcinoma (HCC) remains to be fully elucidated. This study utilized multiple databases to investigate the relationship between SLC2A6 expression and clinical stage, methylation status, drug sensitivity, immune infiltration, and immune checkpoint regulation. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted. Furthermore, in vitro and in vivo experiments were performed to assess the impact of SLC2A6 knockout on the proliferation, migration, invasion, and underlying mechanisms in hepatocellular carcinoma (LIHC) cells. SLC2A6 expression was significantly correlated with tumor prognosis, clinical stage, and methylation levels, and was found to influence immune cell infiltration and immune checkpoint gene expression. In LIHC, SLC2A6 was associated with key biological processes, including the cell cycle, P53 signaling, and ferroptosis. Knockdown of SLC2A6 markedly suppressed the proliferation, migration, and invasion of HCC cells, with this inhibition being closely tied to the ferroptosis pathway. SLC2A6 plays a pivotal role in the regulation of pan-cancer processes, particularly in tumor prognosis and immune-related mechanisms. In LIHC, it emerges as a potential prognostic biomarker and therapeutic target for the regulation of ferroptosis, offering new insights for targeted cancer therapies.

Pan-Cancer Analysis Reveals the Potential of PLOD1 as a Prognostic and Immune Biomarker for Human Cancer

Background/Objectives: Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) is known as an enhancer of collagen fiber deposition and cross-linking stability. However, there is limited information on its function in tumors. In this study, we aimed to elucidate the function and potential mechanism of action of PLOD1 across cancers. Methods: We assessed the pan-cancer expression, mutation, methylation and prognostic value of PLOD1 through multiple online databases. In addition, we performed correlation analyses of its immunological features, as well as functional assessment analyses of PLOD1. Finally, we assessed the effect of PLOD1 knockdown on bladder tumor cells using in vitro experiments. Results: Our findings suggest that PLOD1 is aberrantly expressed in multiple cancer types, accompanied by a poor prognosis. Epigenetic alterations in PLOD1 are highly heterogeneous across a wide range of tumors, and aberrant methylation and copy number variants correlate with a poor prognosis. In the tumor microenvironment, PLOD1 expression correlated positively with the infiltration level of various immunosuppressive cells (e.g., monocytes, macrophages and tumor-associated fibroblasts) and negatively with immune-killing cells (e.g., CD8+ T cells, B cells and CD4+ T cells). In addition, PLOD1 expression was associated with immune checkpoints and immunomodulatory genes. Finally, in vitro experiments demonstrated that knockdown of PLOD1 reduced the proliferation, migration and antiapoptotic abilities of T24 cells. Conclusions: The results of this study demonstrate that PLOD1 is a potential oncogene and prognostic biomarker in pan-cancer; tumor tissues with high PLOD1 expression reveal a relatively immunosuppressive tumor microenvironment.

Engineered CAR-T cells targeting the non-functional P2X purinoceptor 7 (P2X7) receptor as a novel treatment for ovarian cancer

Objectives

Recent studies have identified expression of the non-functional P2X7 (nfP2X7) receptor on various malignant cells including ovarian cancer, but not on normal cells, which makes it a promising tumour-associated antigen candidate for chimeric antigen receptor (CAR)-T-cell immunotherapies. In this study, we assessed the cytotoxic effects of nfP2X7-CAR-T cells on ovarian cancer using in vitro and in vivo models.

Methods

We evaluated the effects of nfP2X7-CAR-T cells on ovarian cancer cell lines (SKOV-3, OVCAR3, OVCAR5), normal peritoneal cells (LP-9) and primary serous ovarian cancer cells derived from patient ascites in vitro using monolayer and 3D spheroid assays. We also evaluated the effects of nfP2X7-CAR-T cells on patient-derived tissue explants, which recapitulate an intact tumour microenvironment. In addition, we investigated the effect of nfP2X7-CAR-T cells in vivo using the OVCAR-3 xenograft model in NOD-scid IL2Rγnull (NSG) mice.

Results

Our study found that nfP2X7-CAR-T cells were cytotoxic and significantly inhibited survival of OVCAR3, OVCAR5 and primary serous ovarian cancer cells compared with un-transduced CD3+ T cells in vitro. However, no significant effects of nfP2X7-CAR-T cells were observed for SKOV3 or normal peritoneal cells (LP-9) cells with low P2X7 receptor expression. Treatment with nfP2X7-CAR-T cells increased apoptosis compared with un-transduced T cells in patient-derived explants and correlated with CD3 positivity. Treatment with nfP2X7-CAR-T cells significantly reduced OVCAR3 tumour burden in mice compared with un-transduced CD3 cells for 7-8 weeks.

Conclusion

This study demonstrates that nfP2X7-CAR-T cells have great potential to be developed as a novel immunotherapy for ovarian cancer.

Recurrent ovarian cancer in Africa: Rate and associated factors at a gynecologic oncology treatment center in Ethiopia-A cross-sectional study

OBJECTIVE

To determine the recurrence rate of epithelial ovarian cancer (EOC) and associated factors in an Ethiopian tertiary setting.

METHODS

A cross-sectional study was conducted on recurrent ovarian cancer at St. Paul's College Millennium Medical College (Ethiopia). Data were collected through chart review using a structured questionnaire. SPSS version 26 was used to analyze the data. Descriptive analysis, bivariate, and multivariate regression analysis were performed as appropriate. Percentages, frequencies, odds ratio with 95% confidence interval (CI) were used to present the results' significance.

RESULTS

A total of 202 patients with EOC were reviewed. The recurrence rate of ovarian cancer (OC) among these patients was 86.1% (a total of 173 patients developed recurrent disease). The commonest site of recurrence was the pelvis (89.1%, 180/202) and the majority of patients with recurrence were platinum sensitive, accounting for 63.8% (129/202) of cases. Age ≥40 years (adjusted odds ratio [AOR], 23.3, CI: 4.3-31.5), macroscopic residual disease (AOR, 5.2, CI: 1.96-17.68), and FIGO Stage III/IV (AOR, 22.11, CI: 8.3-39.13) were associated with recurrence.

CONCLUSION

The recurrence rate of OC in this study was higher than previous reports. Advanced age at first presentation, extent of residual disease after surgery, and FIGO Stage III and IV disease were associated with disease recurrence.

Survival outcomes following interval versus primary debulking surgery in advanced epithelial ovarian cancer: A retrospective cohort study in Lagos, Southwest Nigeria

Background

There is conflicting evidence regarding the survival benefit of interval debulking surgery (IDS) compared to conventional treatment with primary debulking surgery (PDS) in women with advanced epithelial ovarian cancer (EOC).

Objectives

We compared the survivals following PDS followed by adjuvant chemotherapy (ACT) versus IDS after neoadjuvant chemotherapy (NACT) in women with advanced EOC at the gynaecological oncology unit of a tertiary referral centre in Lagos, Southwest Nigeria.

Methods

The data of 126 women with advanced EOC who had standard treatment with either PDS and ACT or NACT and IDS between January 2008 and December 2017 were analyzed. Kaplan-Meier estimates of progression-free (PFS) and overall survival (OS) time stratified by the types of upfront debulking surgery were calculated and compared by employing the log-rank test statistics. Cox proportional hazard models were then used to estimate hazard ratios of the association between the type of surgical debulking and survivals while adjusting for all necessary covariates.

Results

We recorded no statistically significant differences in PFS (adjusted hazard ratio=1.28, 95% confidence interval 0.82-2.01, P=0.282) and OS (adjusted hazard ratio=1.23, 95% confidence interval 0.68-2.25, P=0.491) between IDS and PDS among women with advanced EOC.

Conclusions

There is a need for a larger prospective multicenter study to further compare the impact of upfront surgical debulking types on the survival of women with advanced EOC in our setting. In the meantime, giving interval debulking surgery after a few courses of neoadjuvant chemotherapy should be an acceptable standard of care for women with advanced EOC.

Comprehensive Pan-Cancer Analysis of KIF18A as a Marker for Prognosis and Immunity

KIF18A belongs to the Kinesin family, which participates in the occurrence and progression of tumors. However, few pan-cancer analyses have been performed on KIF18A to date. We used multiple public databases such as TIMER, The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and Human Protein Atlas (HPA) to explore KIF18A mRNA expression in 33 tumors. We performed immunohistochemistry on liver cancer and pancreatic cancer tissues and corresponding normal tissues to examine the expression of KIF18A protein. Univariate Cox regression and Kaplan-Meier survival analysis were applied to detect the effect of KIF18A on overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) of patients with these tumors. Subsequently, we explored KIF18A gene alterations in different tumor tissues using cBioPortal. The relationship between KIF18A and clinical characteristics, tumor microenvironment (TME), immune regulatory genes, immune checkpoints, tumor mutational burden (TMB), microsatellite instability (MSI), mismatch repairs (MMRs), DNA methylation, RNA methylation, and drug sensitivity was applied for further study using the R language. Gene Set Enrichment Analysis (GSEA) was utilized to explore the molecular mechanism of KIF18A. Bioinformatic analysis and immunohistochemical experiments confirmed that KIF18A was up-regulated in 27 tumors and was correlated with the T stage, N stage, pathological stage, histological grade, and Ki-67 index in many cancers. The overexpression of KIF18A had poor OS, DSS, and PFI in adrenocortical carcinoma (ACC), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), brain lower-grade glioma (LGG), liver cancer (LIHC), lung adenocarcinoma (LUAD), and pancreatic cancer (PAAD). Univariate and multivariate regression analysis confirmed KIF18A as an independent prognostic factor for LIHC and PAAD. The mutation frequency of KIF18A is the highest in endometrial cancer. KIF18A expression levels were positively associated with immunocyte infiltration, immune regulatory genes, immune checkpoints, TMB, MSI, MMRs, DNA methylation, RNA methylation, and drug sensitivity in certain cancers. In addition, we discovered that KIF18A participated in the cell cycle at the single-cell level and GSEA analysis for most cancers. These findings suggested that KIF18A could be regarded as a latent prognostic marker and a new target for cancer immunological therapy.

A mAb against surface-expressed FSHR engineered to engage adaptive immunity for ovarian cancer immunotherapy

Despite advances in ovarian cancer (OC) therapy, recurrent OC remains a poor-prognosis disease. Because of the close interaction between OC cells and the tumor microenvironment (TME), it is important to develop strategies that target tumor cells and engage components of the TME. A major obstacle in the development of OC therapies is the identification of targets with expression limited to tumor surface to avoid off-target interactions. The follicle-stimulating hormone receptor (FSHR) has selective expression on ovarian granulosa cells and is expressed on 50%-70% of serous OCs. We generated mAbs targeting the external domain of FSHR using in vivo-expressed FSHR vector. By high-throughput flow analysis, we identified multiple clones and downselected D2AP11, a potent FSHR surface-targeted mAb. D2AP11 identifies important OC cell lines derived from tumors with different mutations, including BRCA1/2, and lines resistant to a wide range of therapies. We used D2AP11 to develop a bispecific T cell engager. In vitro addition of PBMCs and T cells to D2AP11-TCE induced specific and potent killing of different genetic and immune escape OC lines, with EC50s in the ng/ml range, and attenuated tumor burden in OC-challenged mouse models. These studies demonstrate the potential utility of biologics targeting FSHR for OC and perhaps other FSHR-positive cancers.

Cisplatin increases immune activity of monocytes and cytotoxic T-cells in a murine model of epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is an immunologically active malignancy, but thus far immune therapy has had limited success in clinical trials. One barrier to implementation of efficacious immune therapies is a lack of knowledge of the effect of chemotherapy on the monocyte-derived component of the immune infiltrate within the tumor. We utilized the ID8 murine EOC model to investigate alterations within tumor ascites that occur following administration of platinum chemotherapy. Cisplatin treatment resulted in a significant increase in monocytes within the ascites of tumor bearing mice. We identified that CD11b+ cells from the ascites of mice that have been treated with cisplatin elicits an increase in IFN-ɣ expression from CD8+ T-cells compared to CD11b+ cells from a mouse treated with vehicle control (604.0 pg/mL v. 4328.0 pg/mL; p < .0001). Splenocytes derived from tumor bearing mice released increase levels of IFN-ɣ after treatment with cisplatin when incubated with dendritic cells (DCs) and tumor antigen (62.0 v. 92.1 pg/mL; p = .03). Cisplatin induced an increase in T-cell and monocyte/macrophage activation markers (CD62L and CD301). Levels of IL-10, IL-6, and VEGF in the cell free ascites of mice treated with cisplatin decreased (p > .05). These results indicate that treatment with cisplatin leads to an increase of anti-tumor activity within the ascites related to alterations in the ascites monocytes. Further investigation of these findings in humans is necessary to identify how these cells behave in different patient subgroups and if there is a role for monocyte directed therapy in conjunction with T-cell directed therapy and/or chemotherapy.

Prognostic implications of tumour-infiltrating lymphocytes for recurrence in epithelial ovarian cancer

The recurrence of patients with epithelial ovarian cancer (EOC) is largely attributed to tumour cells escaping from the surveillance of immune cells. However, to date there is a lack of studies that have systematically evaluated the associations between the infiltration fraction of immune cells and the recurrence risk of EOC. Based on the micro-ribonucleic acid (microRNA) expression profiles of 441 EOC patients, we constructed a microRNA-based panel with recurrence prediction potential using non-negative matrix factorization consensus clustering. Then, we evaluated the association between recurrence risk and infiltration proportions among 10 immune cell types by CIBERSORT and a multivariable Cox regression model. As a result, we identified a 72-microRNA-based panel that could stratify patients into high and low risk of recurrence. The infiltration of plasma cells and M1 macrophages was consistently significantly associated with the risk of recurrence in patients with EOC. Plasma cells were significantly associated with a decreased risk of relapse [hazard ratio (HR) = 0.58, p = 0.006), while M1 macrophages were associated with an increased risk of relapse (HR = 1.59, p = 0.003). Therefore, the 72-microRNA-based panel, M1 macrophages and plasma cells may hold potential to serve as recurrence predictors of EOC patients in clinical practice.

IL-10 Signaling in the Tumor Microenvironment of Ovarian Cancer

Unlike other malignancies, ovarian cancer (OC) creates a complex tumor microenvironment with distinctive peritoneal ascites consisting of a mixture of several immunosuppressive cells which impair the ability of the patient's immune system to fight the disease. The poor survival rates observed in advanced stage OC patients and the lack of effective conventional therapeutic options have been attributed in large part to the immature dendritic cells (DCs), IL-10 secreting regulatory T cells, tumor-associated macrophages, myeloid-derived suppressor cells, and cancer stem cells that secrete inhibitory cytokines. This review highlights the critical role played by the intraperitoneal presence of IL-10 in the generation of an immunosuppressive tumor microenvironment. Further, the effect of antibody neutralization of IL-10 on the efficacy of DC and chimeric antigen receptor T-cell vaccines will be discussed. Moreover, we will review the influence of IL-10 in the promotion of cancer stemness in concert with the NF-κB signaling pathway with regard to OC progression. Finally, understanding the role of IL-10 and its crosstalk with various cells in the ascitic fluid may contribute to the development of novel immunotherapeutic approaches with the potential to kill drug-resistant OC cells while minimizing toxic side effects.

Non-invasive biomarkers for monitoring the immunotherapeutic response to cancer

Immunotherapy is an efficient way to cure cancer by modulating the patient’s immune response. However, the immunotherapy response is heterogeneous and varies between individual patients and cancer subtypes, reinforcing the need for early benefit predictors. Evaluating the infiltration of immune cells in the tumor and changes in cell-intrinsic tumor characteristics provide potential response markers to treatment. However, this approach requires invasive sampling and may not be suitable for real-time monitoring of treatment response. The recent emergence of quantitative imaging biomarkers provides promising opportunities. In vivo imaging technologies that interrogate T cell responses, metabolic activities, and immune microenvironment could offer a powerful tool to monitor the cancer response to immunotherapy. Advances in imaging techniques to identify tumors' immunological characteristics can help stratify patients who are more likely to respond to immunotherapy. This review discusses the metabolic events that occur during T cell activation and differentiation, anti-cancer immunotherapy-induced T cell responses, focusing on non-invasive imaging techniques to monitor T cell metabolism in the search for novel biomarkers of response to cancer immunotherapy.

Nanomedicine-Combined Immunotherapy for Cancer

BACKGROUND

Immunotherapy for cancer includes Chimeric Antigen Receptor (CAR)-T cells, CAR-natural Killer (NK) cells, PD1, and the PD-L1 inhibitor. However, the proportion of patients who respond to cancer immunotherapy is not satisfactory. Concurrently, nanotechnology has experienced a revolution in cancer diagnosis and therapy. There are few clinically approved nanoparticles that can selectively bind and target cancer cells and incorporate molecules, although many therapeutic nanocarriers have been approved for clinical use. There are no systematic reviews outlining how nanomedicine and immunotherapy are used in combination to treat cancer.

OBJECTIVE

This review aims to illustrate how nanomedicine and immunotherapy can be used for cancer treatment to overcome the limitations of the low proportion of patients who respond to cancer immunotherapy and the rarity of nanomaterials in clinical use.

METHODS

A literature review of MEDLINE, PubMed / PubMed Central, and Google Scholar was performed. We performed a structured search of literature reviews on nanoparticle drug-delivery systems, which included photodynamic therapy, photothermal therapy, photoacoustic therapy, and immunotherapy for cancer. Moreover, we detailed the advantages and disadvantages of the various nanoparticles incorporated with molecules to discuss the challenges and solutions associated with cancer treatment.

CONCLUSION

This review identified the advantages and disadvantages associated with improving health care and outcomes. The findings of this review confirmed the importance of nanomedicinecombined immunotherapy for improving the efficacy of cancer treatment. It may become a new way to develop novel cancer therapeutics using nanomaterials to achieve synergistic anticancer immunity.

An Elucidative Review to Analytically Sieve the Viability of Nanomedicine Market

The advent of the twenty-first century marked a paradigm shift in the healthcare sector with coming of automated, sensitive, targeted medicines and technologies having diagnostic, prophylactic and therapeutic effects. Nanomedicines also attained wide acclamation in their initial years, but the transformation from being the proof of concept to successfully marketed products seems very daunting. Although the reason for this may be attributed to slow but incremental character of many present-day technologies, the review asserts that there are other significant facets that may purvey a thorough explanation of this scenario. The article elaborately discusses the hurdles hindering clinical translation of nanomedicines including scale-up challenges, in vitro in vivo cascade of toxicology assays, along with unrefined manufacturing guidelines, inadequate regulatory approvals, competitive conventional market, etc., leading to hesitant investments by pharmaceutical giants. The paper also explores the economic viability of nanobiotechnology sector through an empirical investigation of the revenue data of various pharmaceutical industries manufacturing nano-based drugs, which indicates minor commercial importance of these medicines. We also laid down a comprehensive set of recommendations to smoothen the translational pathway of nanomedicines from an idea to reality, efface the consumer distrust and push boundaries for development and launching of safe, efficient and commercially successful products. Graphical abstract.

Risk predictors of early recurrence in women with epithelial ovarian cancer in Lagos, Nigeria

Introduction

epithelial ovarian cancer (EOC) is the most lethal gynaecological cancer with a recurrence rate as high as 85% after an initial treatment. However, there are currently no reliable means of predicting the risk of recurrence after first-line treatment. This study investigated the risk factors that predict early recurrence of EOC after primary treatment among women in Lagos, Nigeria.

Methods

this was a retrospective cohort study involving the review of all histologically confirmed EOC patients managed at the Lagos University Teaching Hospital, Lagos, Nigeria over a 7-year period from January 2010 to December 2016. A study proforma was used to retrieve relevant information and descriptive statistics were computed for all data. The associations between variables were tested and multivariate analysis was done to adjust for all the possible characteristics that predict early EOC recurrence.

Results

the rate of recurrence of EOC was 76.4%. Suboptimal debulking surgery is the only independent predictor of early tumour recurrence.

Conclusion

women should be adequately counselled and encouraged to report their symptoms early to ensure optimal primary treatment. Strategic efforts should also be made to further improve subspecialty training programs and skills development in gynaecological oncology in Nigeria and sub-Saharan Africa.

Heterogeneity of immune microenvironment in ovarian cancer and its clinical significance: a retrospective study

Treatment of ovarian cancer (OC) remains the biggest challenge among gynecological malignancies. Immune checkpoint blockade therapy is promising in many cancers but shows low response rates in OC because of its heterogeneity. Although the biological and molecular heterogeneity of OC has been extensively investigated, heterogeneity of immune microenvironment remains elusive. We have collected the expression profiles of 3071 OC patients from 22 publicly available datasets. CIBERSORT was applied to infer the infiltration fraction of 22 immune cells among 2086 patients with CIBERSORT P < .05. We then explored the heterogeneity landscape of immune microenvironment in OC at three levels (immune infiltration, prognostic relevance of immune infiltration, immune checkpoint expression patterns). Multivariable Cox regression model was used to investigate the associations between survival risk and immune infiltration. Constructed immune risk score stratified patients with significantly different survival risk (HR: 1.47, 95% CI: 1.31–1.66, P < .0001). The immune infiltration landscape, prognostic relevance of immune cells, and expression patterns of 79 immune checkpoints exhibited remarkable clinicopathological heterogeneity. For instance, M1 macrophages were significantly associated with better outcomes among patients with high-grade, late-stage, type-II OC (HR: 0.77–0.83), and worse outcomes among patients with type-I OC (HR: 1.78); M2 macrophages were significantly associated with worse outcomes among patients with high-grade, type-II OC (HR: 1.14–1.17); Neutrophils were significantly associated with worse outcomes among patients with high-grade, late-stage, type-I OC (HR: 1.14–1.73). The heterogeneous landscape of immune microenvironment presented in this study provided new insights into prognostic prediction and tailored immunotherapy of OC.

Inhibitory effect on ovarian cancer ALDH+ stem-like cells by Disulfiram and Copper treatment through ALDH and ROS modulation

BACKGROUND

Disulfiram (DSF) is a drug used for treatment of alcoholism that has also displayed promising anti-cancer activity. It unfolds its effects by inhibiting the enzyme activity of aldehyde dehydrogenase (ALDH) isoforms.

METHODS

MTT assay, spheroid formation, clonogenicity assay, qRT-PCR, and ALDH enzyme activity analysis were performed using ovarian cancer cell lines IGROV1, SKOV3 and SKOV3IP1. Cell cycle analyses and measurement of intracellular reactive oxygen species (ROS) were carried out by flow cytometry. ALDH+ and ALDH- cells were isolated by FACS sorting.

RESULTS

ALDH activity was inhibited in ovarian cancer stem cells (the proportion of ALDH+ cells was reduced from 21.7% to 0.391%, 8.4% to 0%, 6.88% to 0.05% in cell lines IGROV1, SKOV3, and SKOV3IP1, respectively). DSF with or without the cofactor copper (Cu²⁺) exhibited cytotoxicity dose- and time-dependent and enhanced cisplatin-induced apoptosis. DSF + Cu²⁺ increased intracellular ROS levels triggering apoptosis of ovarian cancer stem cells (CSC). Significantly more colony and spheroid formation was observed in ALDH+ compared with ALDH- cells (P < 0.01). Moreover, ALDH+ cells were more resistant to cisplatin treatment compared with ALDH-cells (P < 0.05) and also exhibited a lower basal level of ROS. However, no significant difference in ROS accumulation nor in cellular viability was observed in ALDH + cells in comparison to ALDH- cells after pre-treatment with DSF (0.08 μM).

CONCLUSION

Our findings provide evidence that DSF might be employed as a novel adjuvant chemotherapeutic agent in combination with cisplatin for treatment of ovarian cancer.

CD90low MSCs modulate intratumoral immunity to confer antitumor activity in a mouse model of ovarian cancer

Both anti-tumoral and pro-tumoral effects of mesenchymal stem cells (MSCs) in preclinical treatment of ovarian cancer have been controversially demonstrated. In this study, we profiled the phenotypes of mouse compact bone-derived MSCs (CB-MSCs) and bone marrow-derived MSCs (BM-MSCs) and found that CB-MSCs expressed lower CD90 compared to BM-MSCs. We examined gene expression of immune regulating cytokines of CB-MSCs in 2D and 3D culture and under stimulation with TLR4 agonist LPS or immune activator VIC-008. Our data showed that when CB-MSCs were cultured in simulated in vivo 3D condition, CD90 expression was further decreased. Moreover, gene expressions of immune activating cytokines IL-12, IL-21, IFNγ and a pro-inflammatory cytokine CXCL10 in CB-MSCs were increased in 3D culture whereas gene expression of anti-inflammatory cytokines IL-10 and CCL5 were downregulated. Stimulation of CB-MSCs by LPS or VIC-008 presented similar profile of the cytokine gene expressions to that in 3D culture which might benefit the anti-tumor efficacy of CD90low MSCs. The anti-tumor effects of CD90low CB-MSCs alone or in combination with VIC-008 were evaluated in a syngeneic orthotopic mouse model of ovarian cancer. Treatment that combines CB-MSCs and VIC-008 significantly decreased tumor growth and prolonged mouse survival. This was associated with the increase of activated anti-tumoral CD4+ and CD8+ T cells and the decrease of Treg cells in the tumor microenvironment. Taken together, our study demonstrates the synergistic anti-tumoral efficacy by application of CB-MSCs combined with immune activator VIC-008 and provides new insight into CD90low MSCs as a new anti-tumor arsenal.

Nanopharmaceuticals and nanomedicines currently on the market: challenges and opportunities

There has been a revolution in nanotechnology and nanomedicine. Since 1980, there has been a remarkable increase in approved nano-based pharmaceutical products. These novel nano-based systems can either be therapeutic agents themselves, or else act as vehicles to carry different active pharmaceutical agents into specific parts of the body. Currently marketed nanostructures include nanocrystals, liposomes and lipid nanoparticles, PEGylated polymeric nanodrugs, other polymers, protein-based nanoparticles and metal-based nanoparticles. A range of issues must be addressed in the development of these nanostructures. Ethics, market size, possibility of market failure, costs and commercial development, are some topics which are on the table to be discussed. After passing all the ethical and biological assessments, and satisfying the investors as to future profitability, only a handful of these nanoformulations, successfully obtained marketing approval. We survey the range of nanomedicines that have received regulatory approval and are marketed. We discuss ethics, costs, commercial development and possible market failure. We estimate the global nanomedicine market size and future growth. Our goal is to summarize the different approved nanoformulations on the market, and briefly cover the challenges and future outlook.

Natural killer cells inhibit metastasis of ovarian carcinoma cells and show therapeutic effects in a murine model of ovarian cancer

Ovarian cancer has the highest mortality rate and is the most common of all gynecologic malignancies. Novel treatments for ovarian cancer are urgently required to improve outcomes and the overall survival of patients. The present study investigated whether immunotherapy with natural killer (NK) cells affected the survival of mice with ovarian cancer. Results analysis identified adjunctive NK cells as a potential therapeutic method in ovarian cancer. Patient-derived ovarian cells were isolated, cultured and subsequently injected subcutaneously into immune deficient BALB/c-nude mice. Human NK cells were isolated from peripheral blood mononuclear cells and cultured for expansion in vitro. The present results demonstrated that ovarian cells in BALB/c-nude mice did not induce spontaneous ovarian cancer cell metastasis in the NK-treated group. In addition, NK cells activated immune cells in the immune system, which resulted in inhibition of ovarian tumor growth in vitro and in a murine xenograft model of ovarian cancer. The data also indicated that cytotoxic activity of NK cells prevented migration and invasion of ovarian cancer cells, which contributed to prevention of systemic metastasis and suggested that NK cells could be effective cells for therapy against ovarian cancer. Furthermore, NK cells induced apoptosis and increased the number of cluster of differentiation (CD)4⁺, CD8⁺ as well as cytotoxic T lymphocyte responses by intravenous injection in a murine xenograft model of ovarian cancer. These results suggested that NK cells inhibited the systemic metastasis for ovarian cancer cells. In conclusion, the present study suggested that NK cell immunotherapy inhibited systemic metastasis of ovarian cancer cells and improved the survival rate of mice. Sufficient supplementation of NK cells may serve as a promising immunotherapeutic strategy for ovarian cancer.

Targeting Tumor Metabolism: A New Challenge to Improve Immunotherapy

Currently, a marked number of clinical trials on cancer treatment have revealed the success of immunomodulatory therapies based on immune checkpoint inhibitors that activate tumor-specific T cells. However, the therapeutic efficacy of cancer immunotherapies is only restricted to a small fraction of patients. A deeper understanding of key mechanisms generating an immunosuppressive tumor microenvironment (TME) remains a major challenge for more effective antitumor immunity. There is a growing evidence that the TME supports inappropriate metabolic reprogramming that dampens T cell function, and therefore impacts the antitumor immune response and tumor progression. Notably, the immunosuppressive TME is characterized by a lack of crucial carbon sources critical for T cell function and increased inhibitory signals. Here, we summarize the basics of intrinsic and extrinsic metabolic remodeling and metabolic checkpoints underlying the competition between cancer and infiltrating immune cells for nutrients and metabolites. Intriguingly, the upregulation of tumor programmed death-L1 and cytotoxic T lymphocyte-associated antigen 4 alters the metabolic programme of T cells and drives their exhaustion. In this context, targeting both tumor and T cell metabolism can beneficially enhance or temper immunity in an inhospitable microenvironment and markedly improve the success of immunotherapies.

Expression of tumor antigens on primary ovarian cancer cells compared to established ovarian cancer cell lines

In order to select a suitable combination of cancer cell lines as an appropriate source of antigens for dendritic cell-based immunotherapy of ovarian cancer, we analyzed the expression level of 21 tumor associated antigens (BIRC5, CA125, CEA, DDX43, EPCAM, FOLR1, Her-2/neu, MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A6, MAGE-A10, MAGE-A12, MUC-1, NY-ESO-1, PRAME, p53, TPBG, TRT, WT1) in 4 established ovarian cancer cell lines and in primary tumor cells isolated from the high-grade serous epithelial ovarian cancer tissue. More than 90% of tumor samples expressed very high levels of CA125, FOLR1, EPCAM and MUC-1 and elevated levels of Her-2/neu, similarly to OVCAR-3 cell line. The combination of OV-90 and OVCAR-3 cell lines showed the highest overlap with patients' samples in the TAA expression profile.

Transcriptional profiling of NCI/ADR-RES cells unveils a complex network of signaling pathways and molecular mechanisms of drug resistance

Background

Ovarian cancer has the highest mortality rate among all the gynecological cancers. This is mostly due to the resistance of ovarian cancer to current chemotherapy regimens. Therefore, it is of crucial importance to identify the molecular mechanisms associated with chemoresistance.

Methods

NCI/ADR-RES is a multidrug-resistant cell line that is a model for the study of drug resistance in ovarian cancer. We carried out a microarray-derived transcriptional profiling analysis of NCI/ADR-RES to identify differentially expressed genes relative to its parental OVCAR-8.

Results

Gene-expression profiling has allowed the identification of genes and pathways that may be important for the development of drug resistance in ovarian cancer. The NCI/ADR-RES cell line has differential expression of genes involved in drug extrusion, inactivation, and efficacy, as well as genes involved in the architectural and functional reorganization of the extracellular matrix. These genes are controlled through different signaling pathways, including MAPK–Akt, Wnt, and Notch.

Conclusion

Our findings highlight the importance of using orthogonal therapies that target completely independent pathways to overcome mechanisms of resistance to both classical chemotherapeutic agents and molecularly targeted drugs.

MtHsp70-CLIC1-pulsed dendritic cells enhance the immune response against ovarian cancer

Approximately 80% of ovarian cancer (OC) is diagnosed at late stages, and most patients die within 5 years of diagnosis due to recurrence or drug resistance. Novel treatments are required to improve patient survival. Immune therapy against cancer is promising; however, therapeutic vaccination has been limited by the inability of tumor antigens to induce effective immune responses. Chloride intracellular channel 1 (CLIC1) was previously identified as a possible tumor marker for OC. In this study, we constructed a recombinant protein by conjugating the extracellular domain of CLIC1 to the carboxyl terminus of Mycobacterium tuberculosis heat shock protein 70 (MtHsp70). Human dendritic cells (DCs) derived from cortical blood were pulsed with the fusion protein, and the antitumor effect of human cytotoxic T lymphocytes (CTLs) stimulated by autologous DCs was assessed in NOG mice. MtHsp70-CLIC1 promoted the phenotypic maturation of human DCs and the secretion of Th1-associated cytokines in vitro. MtHsp70-CLIC1-stimulated CTLs generated a CLIC1-specific immune response both in vitro and in vivo. These results indicate that DCs pulsed with MtHsp70-CLIC1 can enhance antitumor immunity against OC, providing a novel immune therapeutic strategy.

HM015k, a Novel Silybin Derivative, Multi-Targets Metastatic Ovarian Cancer Cells and Is Safe in Zebrafish Toxicity Studies

This study was designed to determine the in vitro mechanisms by which the novel silybin derivative, (E)-3-(3-(benzyloxy) phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (HM015k or 15k), produces its anticancer efficacy in ovarian cancer cells. Compound 15k induced apoptosis in ovarian cancer cells in a time-dependent manner by significantly upregulating the expression of Bax and Bak and downregulating the expression of Bcl-2. Interestingly, 15k induced the cleavage of Bax p21 into its more efficacious cleaved form, Bax p18. In addition, caspase 3 and caspase 9 were cleaved to their active forms, inducing the cleavage of poly ADP ribose polymerase (PARP) and β-catenin. Furthermore, in OV2008 cells, 15k induced significant cleavage in nuclear β-catenin to primarily inactive fragments of lower molecular weight. Furthermore, 15k reversed the metastatic potential of OV2008 cells by inhibiting their migration and invasiveness. The mesenchymal phenotype in OV2008 was reversed by 15k, causing cells to be rounder with epithelial-like phenotypes. The 15k-induced reversal was further confirmed by significant upregulation of the E-cadherin expression, an epithelial marker, while N-cadherin, a mesenchymal marker, was downregulated in OV2008 cells. Compound 15k inhibited the expression of the oncogenic c-Myc protein, downregulated proteins DVL3 and DVL2 and significantly upregulated cyclin B1. Also, 15k significantly downregulated the expression levels of ABCG2 and ABCB1 transporters in resistant ABCG2 overexpressing H460/MX20 and resistant ABCB1 overexpressing MDCK/MDR1 cells, respectively. Finally, 15k was safe in zebrafish in vivo model at concentrations up to 10 μM and induced no major toxicities in cardiac, morphology and swimming position parameters. Overall, 15k is a multi-targeted inhibitor with efficacy against metastatic and resistant ovarian cancer. Future in vivo studies will be conducted to determine the efficacy of 15k in tumor-bearing animals.

Dihydromyricetin Induces Apoptosis and Reverses Drug Resistance in Ovarian Cancer Cells by p53-mediated Downregulation of Survivin

Ovarian cancer is one of the leading causes of death in gynecological malignancies, and the resistance to chemotherapeutic agents remains a major challenge to successful ovarian cancer chemotherapy. Dihydromyricetin (DHM), a natural flavonoid derived from Ampeopsis Grossdentata, has been widely applied in food industry and medicine for a long time. However, little is known about the effects of DHM on ovarian cancer and the underlying mechanisms. In this study, we demonstrated that DHM could effectively inhibit the proliferation of ovarian cancer cells and induce cell apoptosis. Survivin, an inhibitor of apoptosis (IAPs) family member, exhibited a decreased expression level after DHM treatment, which may be attributed to the activation of p53. Moreover, DHM markedly sensitized paclitaxel (PTX) and doxorubicin (DOX) resistant ovarian cancer cells to PTX and DOX by inhibiting survivin expression. Collectively, our findings highlight a previously undiscovered effect of DHM, which induces apoptosis and reverses multi-drug resistance against ovarian cancer cells through downregulation of survivin.

Adoptive immunotherapy against ovarian cancer

The standard front-line therapy for epithelial ovarian cancer (EOC) is combination of debulking surgery and platinum-based chemotherapy. Nevertheless, the majority of patients experience disease recurrence. Although extensive efforts to find new therapeutic options, cancer cells invariably develop drug resistance and disease progression. New therapeutic strategies are needed to improve prognosis of patients with advanced EOC.

Recently, several preclinical and clinical studies investigated feasibility and activity of adoptive immunotherapy in EOC. Our aim is to highlight prospective of adoptive immunotherapy in EOC, focusing on HLA-restricted Tumor Infiltrating Lymphocytes (TILs), and MHC-independent immune effectors such as natural killer (NK), and cytokine-induced killer (CIK). Adoptive cell therapy (ACT) has shown activity in several pre-clinical models. Available preclinical and clinical data suggest that adoptive cell therapy may provide the best benefit in settings of low tumor burden, minimal residual disease, or maintenance therapy. Further studies are needed to better define the optimal clinical setting.

Downregulation of SASH1 correlates with tumor progression and poor prognosis in ovarian carcinoma

SAM- and SH3-domain containing 1 (SASH1) is a recently identified tumor suppressor gene that is required in the tumorigenesis of breast and other solid carcinomas. The SASH1 protein contains SH3 and SAM domains, indicating that it may serve an important role in intracellular signal transduction. The purpose of the present study was to investigate the expression of SASH1 in ovarian carcinoma and the correlation between its expression with clinical pathological features and clinical significance, and the effect of SASH1 on cell proliferation, apoptosis and migration of ovarian SKOV3 cells. The human ovarian carcinoma tissues and adjacent normal tissues were collected following surgery. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect the expression levels of SASH1 mRNA and protein, respectively. The expression levels of SASH1 mRNA and protein in ovarian carcinoma tissues were significantly lower than that observed in adjacent normal tissues (P<0.05). The expression levels of SASH1 in samples from patients without lymph nodes metastasis and patients with early FIGO stage was lower than those with lymph nodes metastasis and patients with advanced FIGO stage (P<0.05). Flow cytometry analysis and Transwell invasion chamber experiments were used to investigate the effect of SASH1 on the cell proliferation, apoptosis and migration of SKOV3 cells. The recombinant plasmid pcDNA3.1-SASH1 was constructed and transfected into SKOV3 cells. In addition, the SKOV3 cells in the pcDNA3.1-SASH1 group exhibited significantly reduced cell growth, proliferation, and migration ability compared to the empty vector group and normal group (P<0.01). There were a greater number of apoptotic cells in the pcDNA3.1-SASH1 group compared to the empty vector group and normal group (P<0.01). Taken together, these results indicated that SASH1 may be a tumor suppressor gene in ovarian carcinoma, and SASH1 expression inhibited growth, proliferation and migration, and enhanced apoptosis of SKOV3 cells.

Induced Pluripotent Stem Cell-Derived Natural Killer Cells for Treatment of Ovarian Cancer

Natural killer (NK) cells can provide effective immunotherapy for ovarian cancer. Here, we evaluated the ability of NK cells isolated from peripheral blood (PB) and NK cells derived from induced pluripotent stem cell (iPSC) to mediate killing of ovarian cancer cells in a mouse xenograft model. A mouse xenograft model was used to evaluate the intraperitoneal delivery of three different NK cell populations: iPSC-derived NK cells, PB-NK cells that had been activated and expanded in long-term culture, and overnight activated PB-NK cells that were isolated through CD3/CD19 depletion of PB B and T cells. Bioluminescent imaging was used to monitor tumor burden of luciferase expressing tumor lines. Tumors were allowed to establish prior to administering NK cells via intraperitoneal injection. These studies demonstrate a single dose of any of the three NK cell populations significantly reduced tumor burden. When mice were given three doses of either iPSC-NK cells or expanded PB-NK cells, the median survival improved from 73 days in mice untreated to 98 and 97 days for treated mice, respectively. From these studies, we conclude iPSC-derived NK cells mediate antiovarian cancer killing at least as well as PB-NK cells, making these cells a viable resource for immunotherapy for ovarian cancer. Due to their ability to be easily differentiated into NK cells and their long-term expansion potential, iPSCs can be used to produce large numbers of well-defined NK cells that can be banked and used to treat a large number of patients including treatment with multiple doses if necessary.

Effect of targeted ovarian cancer immunotherapy using ovarian cancer stem cell vaccine

Background

Accumulating evidence has shown that different immunotherapies for ovarian cancer might overcome barriers to resistance to standard chemotherapy. The vaccine immunotherapy may be a useful one addition to conditional chemotherapy regimens. The present study investigated the use of vaccine of ovarian cancer stem cells (CSCs) to inhibit ovarian cancer growth.

Methods

CD117⁺CD44⁺CSCs were isolated from human epithelial ovarian cancer (EOC) SKOV3 cell line by using a magnetic-activated cell sorting system. Pre-inactivated CD117⁺CD44⁺CSC vaccine was vacccinated into athymic nude mice three times, and then the mice were challenged subcutaneously with SKOV3 cells. The anti-tumor efficacy of CSC vaccine was envaluated by in vivo tumorigenicity, immune efficient analysis by flow cytometer, and enzyme-linked immunosorbent assays, respectively.

Results

The CD117⁺ CD44⁺CSC vaccine increased anti-ovarian cancer efficacy in that it depressed ovarian cancer growth in the athymic nude mice. Vaccination resulted in enhanced serum IFN-γ, decreased TGF-β levels, and increased cytotoxic activity of natural killer cells in the CD117⁺ CD44⁺CSC vaccine immunized mice. Moreover, the CSC-based vaccine significantly reduced the CD117⁺CD44⁺CSC as well as the aldehyde dehydrogenase 1 positive cell populations in the ovarian cancer tissues in the xenograft mice.

Conclusion

The present study provided the first evidence that human SKOV3 CD117⁺ CD44⁺CSC-based vaccine may induce the anti-ovarian cancer immunity against tumor growth by reducing the CD117⁺CD44⁺CSC population.

Maintenance treatment with oral cyclophosphamide and bevacizumab in patients with recurrent epithelial ovarian cancer

AIM

To evaluate the efficacy and safety of maintenance treatment with oral cyclophosphamide (Cy) and bevacizumab (Bev) in patients with recurrent ovarian cancer.

PATIENTS & METHODS

Induction treatment consisted of cisplatin, epirubicin, Cy and Bev every 3 weeks, for a maximum of six cycles. Maintenance treatment consisted of oral Cy 50 mg, days 1-14 and Bev 15 mg/kg, every 3 weeks until disease progression occurred.

RESULTS

In total, 39 patients were enrolled: after induction chemotherapy, the objective response was 74.3%. The median progression-free survival was 13.3 months, and the median overall survival was 33.2 months. Toxicity during maintenance treatment was mild.

CONCLUSION

Maintenance with Cy and Bev may achieve encouraging results in terms of progression-free survival and overall survival in recurrent ovarian cancer patients.