Advances in ovarian cancer therapy

Dual-mode imaging and therapeutic effects of drug-loaded phase-transition nanoparticles combined with near-infrared laser and low-intensity ultrasound on ovarian cancer

Chemotherapy and photo-sonodynamic therapy (PSDT) can be combined through drug delivery nano-platforms to enhance the anti-tumor efficacy, however, which is limited by hypoxia in tumor, thereby causing chemotherapy resistance. Perfluoropentane (PFP) has the ability to carry oxygen and to enhance ultrasound or photoacoustic imaging after vaporization. Herein, we constructed a kind of nanoparticles (PTX/ICG and oxygen loaded PLGA nanoparticles (PIO_NPs)), which had PFP core carrying oxygen and PLGA shell loaded indocyanine green (ICG) and paclitaxel (PTX). PIO_NPs harbored good optical stability and the ability to transit phase. Moreover, it could rapidly release PTX and generate ROS under the mediation by near-infrared laser and low-intensity ultrasound. The PIO_NPs enhanced contrast of the ultrasound and PA imaging. In particular, PIO_NPs may be used to monitor and guide treatment for the accumulation of PIO_NPs at tumor site can be observed by PA imaging. Compared with PTX or other nanoparticles, PIO_NPs combined with laser and ultrasound (L.U) significantly induced apoptosis of SKOV3 cells and inhibited SKOV3 tumor growth. Therefore, PIO_NPs are of great potential in cancer imaging and therapy.

Niraparib - A promising drug with hematological toxicity

Ovarian cancer is the second most common and the most lethal gynecological malignancy in the western world. Unfortunately, there are lack of methods for early screening and diagnosis of the disease. Because of this, most of the cases are diagnosed at an advanced stage and have poor prognosis. The standard treatment of ovarian cancer is maximal cytoreductive surgical debulking followed by platinum-based chemotherapy. There are new molecular agents available for maintenance therapy of ovarian cancer including anti-angiogenic therapies, poly adenosine diphosphate ribose polymerase inhibitors, inhibitors of growth factor signaling, or folate receptor inhibitors, as well as several immunotherapeutic approaches. Niraparib is a poly adenosine diphosphate ribose polymerase inhibitor that has shown to be clinically effective as maintenance therapy in patients with platinum sensitive, recurrent ovarian cancer. Studies have shown the median duration of progression-free survival was significantly longer among those receiving niraparib than among those receiving placebo, regardless of presence or absence of BRCA gene mutations or homologous recombination deficiency status. Studies have shown that treatment-emergent Grade 3 or Grade 4 hematological events were observed in patients receiving niraparib including thrombocytopenia (33.8%), anemia (25.3%) and neutropenia (19.6%). Most of the hematological laboratory abnormalities occurred within the first three treatment cycles. After dose adjustment, the incidence of hematological abnormalities was infrequent beyond cycle 3. We are reporting two cases of Grade III/IV neutropenia and thrombocytopenia in patients treated with niraparib in our institution. Unfortunately, one of the patients succumbed to septic shock secondary to right lower lobe pneumonia while severely neutropenic. The second patient's blood counts improved after discontinuing the medication and with supportive transfusions during the hospitalization.

Nanoparticle Delivery of TWIST Small Interfering RNA and Anticancer Drugs: A Therapeutic Approach for Combating Cancer

Breast and ovarian cancer are the leading cause of cancer-related deaths in women in the United States with over 232,000 new Breast Cancer (BC) diagnoses expected in 2018 and almost 40,000 deaths and an estimated 239,000 new ovarian cancer (OC) cases and 152,000 deaths worldwide annually. OC is the most lethal gynecologic malignancy. This high mortality rate is due to tumor recurrence and metastasis, primarily caused by chemoresistant cancer stem-like cells (CSCs). Triple Negative Breast Cancer (TNBC) patients also become resistant to chemotherapy due to recurrence of CSCs. Currently, no ovarian or breast cancer therapies target CSC specifically. TWIST is overexpressed in the majority of chemoresistant cancers resulting in a low survival rate. Our long-term goal is to develop novel treatments for women with ovarian and breast cancer, specifically treatments that sensitize chemoresistant tumors. Despite successful initial surgery and chemotherapy, over 70% of advanced EOC will recur, and only 15-30% of recurrent disease will respond to chemotherapy (Cortez et al., 2017; Berezhnaya, 2010; Jackson et al., 2015). Moreover, drug resistance causes treatment failure in over 90% of patients with metastatic disease (Solmaz et al., 2015). Thus, recurrent metastatic disease is a major clinical challenge without effective therapy. One of the major challenges in the treatment of breast cancer is the presence of a subpopulation of cancer cells that are chemoresistant (CRC) and metastatic. Given that metastasis is the driving force behind mortality for breast and ovarian cancer patients, it is essential to identify the characteristics of these aberrant cancer cells that allow them to spread to distant sites in the body and develop into metastatic tumors. Understanding the metastatic mechanisms driving cancer cell dispersal will open the door to developing novel therapies that prevent metastasis and improve long-term outcomes for patients. In this chapter we assess the feasibility of targeting the Twist and EMT signaling pathways in breast and ovarian cancer. Additional discussions of the pathways that mediate epithelial-mesenchymal transition (EMT), a process that can give rise to chemoresistance. We review potential treatment strategies for targeting EMT and drug resistance as well as the problems that may arise with these targeted delivery therapeutic approaches. Finally, we examine recent advances in the field, including cancer stem cell targeted nanoparticle delivery and small interference RNA (siRNA) technology, and discuss the impact that these approaches may have on translating much needed therapeutic approaches into the clinic, for the benefit of patients battling this devastating disease.

Risk of selected gastrointestinal toxicities associated with poly (ADP-ribose) polymerase (PARP) inhibitors in the treatment of ovarian cancer: a meta-analysis of published trials

Aims

We aimed to comprehensively assess the risk of gastrointestinal toxicities associated with poly (ADP-ribose) polymerase inhibitors (PARPis) in the treatment of ovarian cancer patients.

Materials and methods

We searched several databases for relevant trials. Eligible studies included prospective Phase II and III trials of ovarian cancer patients on the four PARPis (olaparib, veliparib, niraparib and rucaparib), describing events of nausea, vomiting, diarrhea, and constipation. Summary incidence, relative risk (RR), and 95% CIs were calculated employing fixed- or random-effects models.

Results

A total of 2,286 ovarian cancer patients from 12 trials were included for analysis. Our results showed that summary incidences of all-grade gastrointestinal events in ovarian cancer patients were nausea 68.8% (95% CI, 63.5%–73.6%), vomiting 36.2% (95% CI, 30.9%–41.8%), diarrhea 25.3% (95% CI, 21.2%–29.8%), and constipation 25.3% (95% CI, 17.9%–34.5%). The RRs of all-grade nausea, vomiting, diarrhea, and constipation were 2.00 (95% CI: 1.79–2.24; P<0.001), 2.12 (95% CI: 1.75–2.58; P<0.001), 1.20 (95% CI: 1.01–1.44; P=0.044), and 1.20 (95% CI: 0.88–1.80; P=0.21); respectively. While, the RRs of high-grade nausea, vomiting, diarrhea, and constipation were 3.74 (95% CI: 1.50–9.36; P=0.005), 2.81 (95% CI: 1.17–6.74; P=0.02), 0.56 (95% CI: 0.22–1.43; P=0.23), 0.92 (95% CI: 0.34–2.49, P=0.87); respectively.

Conclusion

Our study suggests that the risk of all-grade gastrointestinal toxicities associated with PARPis, excepting constipation, is significantly increased in ovarian cancer patients. And the use of PARPis significantly increased the risk of developing high-grade nausea and vomiting, but not for diarrhea and constipation. Close clinical monitoring is recommended when administering these drugs.

MiR-1294 confers cisplatin resistance in ovarian Cancer cells by targeting IGF1R

BACKGROUND

Dysregulation of miRNAs is critical for chemosensitivity to platinum-based agents in ovarian cancer (OC) which is the most aggressive gynecological cancer. However, the underlying mechanisms of miRNA-regulated platinum resistance in ovarian cancer remain unclear. In this study, we intended to investigate the effect of miR-1294 on platinum-resistant OC.

METHODS

The expression of miR-1294 in OC tissues (n = 30) and cell lines was measured by qRT-PCR. Cell transfection was carried out to establish miR-1294 overexpression or knockdown. MTT and clone formation assays were performed to examine proliferation in OC cells. Additionally, wound healing and tumor invasion assays were used to investigate cell migration and invasion, respectively. Finally, the expression of epithelial-to-mesenchymal transition (EMT)-associated proteins was measured in OC cells by western blot.

RESULTS

Our results showed that miR-1294 dysregulation manipulated OC cisplatin resistance through regulating IGF1R. Knockdown of IGF1R decreased SKOVP/DDP cell proliferation, migration, invasion and EMT. Moreover, overexpression of miR-1294 prevented OC cisplatin resistance.

CONCLUSION

Our results indicated that epigenetic regulation of IGF1R via miR-1294 was essential for cisplatin resistance in OC and provide a new avenue for OC treatment.

Establishment and Characterization of the Novel High-Grade Serous Ovarian Cancer Cell Line OVPA8

High-grade serous ovarian carcinoma (HGSOC) is the most frequent histological type of ovarian cancer and the one with worst prognosis. Unfortunately, the majority of established ovarian cancer cell lines which are used in the research have unclear histological origin and probably do not represent HGSOC. Thus, new and reliable models of HGSOC are needed. Ascitic fluid from a patient with recurrent HGSOC was used to establish a stable cancer cell line. Cells were characterized by cytogenetic karyotyping and short tandem repeat (STR) profiling. New generation sequencing was applied to test for hot-spot mutations in 50 cancer-associated genes and fluorescence in situ hybridization (FISH) analysis was used to check for TP53 status. Cells were analyzed for expression of several marker genes/proteins by reverse-transcription polymerase chain reaction (RT-PCR), fluorescence-activated cell sorting (FACS), and immunocytochemistry (ICC). Functional tests were performed to compare OVPA8 cells with five commercially available and frequently used ovarian cancer cell lines: SKOV3, A2780, OVCAR3, ES2, and OAW42. Our newly-established OVPA8 cell line shows morphologic and genetic features consistent with HGSOC, such as epithelial morphology, multiple chromosomal aberrations, TP53 mutation, BRCA1 mutation, and loss of one copy of BRCA2. The OVPA8 line has a stable STR profile. Cells are positive for EpCAM, CK19, and CD44; they have relatively low plating efficiency/ability to form spheroids, a low migration rate, and intermediate invasiveness in matrigel, as compared to other ovarian cancer lines. OVPA8 is sensitive to paclitaxel and resistant to cisplatin. We also tested two FGFR inhibitors; OVPA8 cells were resistant to AZD4547 (AstraZeneca, London, UK), but sensitive to the new inhibitor CPL304-110-01 (Celon Pharma, Łomianki/Kiełpin, Poland). We have established and characterized a novel cell line, OVPA8, which can be a valuable preclinical model for studies on high-grade serous ovarian cancer.

Long non-coding RNA Linc00312 modulates the sensitivity of ovarian cancer to cisplatin via the Bcl-2/Caspase-3 signaling pathway

Chemotherapy is one of the main treatments for ovarian cancer (OC). Cisplatin combined with paclitaxel is a commonly used chemotherapy regimen. However, effective cancer therapy is hindered by a patient's resistance to cisplatin. The mechanism that potentially leads to that resistance is unclear. The current study examined the mechanism by which Linc00312 is involved in resistance to cisplatin in OC. Quantitative real-time PCR (RT-qPCR) was used to test for expression of Linc00312 in freshly frozen tissue samples of OC and in SKOV3 and SKOV3/DDP cells. In situ hybridization was performed to examine the distribution of Linc00312 expression in paraffin-embedded histological sections that were sensitive or resistant to cisplatin. The cell counting kit-8 assay was used to detect cell viability. Flow cytometry was used to measure cell apoptosis. RT-qPCR was performed to confirm changes in expression of MDR1, MRP1, Bcl-2, Bax, Caspase-3, and Caspase-9 mRNA. Levels of MDR1, Bcl-2, Bax, Caspase-3, and Caspase-9 protein were detected with Western blotting. Experiments indicated that the expression of Linc00312 decreased significantly in SKOV3/DDP cells compared to that in SKOV3 cells. Upregulation of Linc00312 can considerably increase the sensitivity of SKOV3/DDP cells to cisplatin, while down-regulation of Linc00312 has the exact opposite effect in SKOV3 cells. Linc00312 enhanced the sensitivity of SKOV3/DDP cells to cisplatin by promoting cell apoptosis via the Bcl-2/Caspase-3 signaling pathway. These findings suggest that Linc00312 may be a promising clinical strategy for the treatment of drug-resistant OC.

Drawing a link between the thromboxane A2 pathway and the role of platelets and tumor cells in ovarian cancer

Ovarian cancer is the most lethal gynecologic malignancy among women. Due to the heterogeneity and complexity of the disease, as well as the insidious onset of symptoms, timely diagnosis remains extremely challenging. Despite recent advances in chemotherapy regimens for ovarian cancer patients, many still suffer from recurrence and ultimately succumb to the disease; thus, there is an urgent need for the identification of novel therapeutic targets. Within this rapidly evolving field, the role of platelets in the ovarian cancer tumor microenvironment has garnered increased attention. It is well-established that platelets and tumor cells exhibit bidirectional communication in which platelets enhance tumor cell invasion, extravasation, and protection from host system defenses, while tumor cells serve as platelet agonists, increasing platelet adhesion, aggregation, and degranulation. This mini-review focuses on the platelet-tumor cell relationship in ovarian cancer, specifically highlighting the essential role of bioactive lipid mediators at this interface.

The lncRNA TP73-AS1 promotes ovarian cancer cell proliferation and metastasis via modulation of MMP2 and MMP9

Ovarian cancer is one of the most common gynecologic malignancy with poor prognosis. Recently, long noncoding RNAs (lncRNAs) have been identified as key regulators in cancer development. The current study investigated the role of lncRNA P73 antisense RNA 1T (TP73-AS1) in ovarian cancer. Quantitative real-time polymerase chain reaction determined the expression levels of TP-73AS1, matrix metallopeptidases (MMPs) messenger RNA. Cell proliferative ability, cell invasion, and migration were CCK-8 and colony formation, and transwell invasion and migration assays, respectively. The protein levels of matrix metallopeptidase 2 (MMP2) and MMP9 were measured by Western blot. TP73-AS1 was upregulated in the ovarian cancer tissues and ovarian cancer cells, and upregulation of TP73-AS1 was associated with poor prognosis. Knockdown of TP73-AS1 significantly suppressed cell proliferation, invasion, and migration of SKOV3 cells, and overexpression of TP73-AS1 promoted cell proliferation, invasion, and migration of OVCA429 cells. In addition, knockdown of TP73-AS1 suppressed the in vivo tumor growth. Tumor metastasis RT² profiler polymerase chain reaction array showed that MMP2 and MMP9 was significantly upregulated by TP73-AS1 overexpression in ovarian cancer cells. TP73-AS1 overexpression enhanced the expression of MMP2 and MMP9 in ovarian cancer cells. Knockdown of MMP2 and MMP9 attenuated the effects of TP73-AS1 overexpression on cell invasion and migration. The clinical data showed that MMP2 and MMP9 were upregulated and positively correlated with TP73-AS1 expression in ovarian cancer tissues. Collectively, our results demonstrated the oncogenic role of TP73-AS1 in ovarian cancer, and targeting TP73-AS1 may represent a novel approach in battling against ovarian cancer.

Co-expression and prognostic significance of the HER family members, EGFRvIII, c-MET, CD44 in patients with ovarian cancer

EGFR and HER-2 are important targets but none of the monoclonal antibodies or small molecule tyrosine kinase inhibitors specific for the HER members has been approved for the treatment of patients with ovarian cancers. In some studies, co-expression of other growth factor receptors has been associated with resistance to therapy with the HER inhibitors. The aim of the present study was to determine the relative expression, cellular location, and prognostic significance of HER-family members, the EGFR mutant (EGFRvIII) c-MET, IGF-1R and the cancer stem cell biomarker CD44 in 60 patients with FIGO stage III and IV ovarian cancer. At cut off >5% of tumour cells with positive staining, 62%, 59%, 65% and 45% of the cases were EGFR, HER-2, HER-3 and HER-4 positive, and 3%, 22% and 48.3% of the cases were positive for EGFRvIII, c-MET, and CD44 respectively. Interestingly, 23% co-expressed all four members of the HER family. On univariate analysis, only EGFR staining at >50% of tumour cells (HR = 3.57, p = 0.038) and CD44 staining at 3+ intensity (HR = 7.99, p = 0.004) were associated with a poorer overall survival. EGFR expression (HR = 2.83, p = 0.019) and its co-expression with HER-2, HER-3, HER-2/HER-3, and c-MET were all associated with poorer disease-free survival. Our results suggest co-expression of the HER-family members is common in Stage III and IV ovarian cancer patients. Further studies on the prognostic significance and predictive value of all HER family member proteins for the response to treatment with various forms of the HER inhibitors are warranted.