Ascites Increases Expression/Function of Multidrug Resistance Proteins in Ovarian Cancer Cells

Heterogeneous effects of cytotoxic chemotherapies for platinum-resistant ovarian cancer

BACKGROUND

Single-agent chemotherapy with or without bevacizumab (Bev) is a standard therapy for platinum-resistant ovarian cancer (PR-OC). However, there is a lack of literature on chemotherapy agent selection in heterogenous PR-OC. Therefore, we aimed to clarify the heterogeneous treatment effects of each chemotherapy agent.

METHODS

Patients who underwent single-drug chemotherapy agents or Bev combination therapy for PR-OC between January 2009 and June 2022 were included in this study. We assessed the impact of each chemotherapy agent on the time to treatment failure (TTF) according to histological type, platinum-free interval (PFI), and Bev usage.

RESULTS

A total of 158 patients received 343 different chemotherapy regimens. In patients with clear cell carcinoma/mucinous carcinoma (CC/MC), gemcitabine (GEM) had the strongest effect with a median TTF of 5.3 months, whilst nedaplatin (NDP) had the lowest effect with a median TTF of 1.4 months. In contrast, in the non-CC/MC group, irinotecan (CPT-11) and NDP had a better TTF than GEM and pegylated liposomal doxorubicin (PLD). There were notable differences in the treatment efficacy of NDP according to PFI. Specifically, NDP prolonged the TTF in patients with a PFI ≥ 3 months. Compared with GEM alone, GEM + Bev tended to prolong the TTF more effectively; however, an additive effect was not observed with PLD + Bev.

CONCLUSIONS

This study demonstrated that the effect of chemotherapy agents differed according to the tumor and background characteristics of the patient. Our findings will improve selection of effective therapies for patients with PR-OC by considering their background characteristics.

The Application of an Extracellular Vesicle-Based Biosensor in Early Diagnosis and Prediction of Chemoresponsiveness in Ovarian Cancer

BACKGROUND

Ovarian cancer (OVCA) is the most fatal gynecological cancer with late diagnosis and plasma gelsolin (pGSN)-mediated chemoresistance representing the main obstacles to treatment success. Since there is no reliable approach to diagnosing patients at an early stage as well as predicting chemoresponsiveness, there is an urgent need to develop a diagnostic platform for such purposes. Small extracellular vesicles (sEVs) are attractive biomarkers given their potential accuracy for targeting tumor sites.

METHODS

We have developed a novel biosensor which utilizes cysteine-functionalized gold nanoparticles that simultaneously bind to cisplatin (CDDP) and plasma/cell-derived EVs, affording us the advantage of predicting OVCA chemoresponsiveness, and early diagnosis using surface-enhanced Raman spectroscopy.

RESULTS

We found that pGSN regulates cortactin (CTTN) content resulting in the formation of nuclear- and cytoplasmic-dense granules facilitating the secretion of sEVs carrying CDDP; a strategy used by resistant cells to survive CDDP action. The clinical utility of the biosensor was tested and subsequently revealed that the sEV/CA125 ratio outperformed CA125 and sEV individually in predicting early stage, chemoresistance, residual disease, tumor recurrence, and patient survival.

CONCLUSION

These findings highlight pGSN as a potential therapeutic target and provide a potential diagnostic platform to detect OVCA earlier and predict chemoresistance; an intervention that will positively impact patient-survival outcomes.

Mechanisms of Drug Resistance in Ovarian Cancer and Associated Gene Targets

In the United States, over 100,000 women are diagnosed with a gynecologic malignancy every year, with ovarian cancer being the most lethal. One of the hallmark characteristics of ovarian cancer is the development of resistance to chemotherapeutics. While the exact mechanisms of chemoresistance are poorly understood, it is known that changes at the cellular and molecular level make chemoresistance challenging to treat. Improved therapeutic options are needed to target these changes at the molecular level. Using a precision medicine approach, such as gene therapy, genes can be specifically exploited to resensitize tumors to therapeutics. This review highlights traditional and novel gene targets that can be used to develop new and improved targeted therapies, from drug efflux proteins to ovarian cancer stem cells. The review also addresses the clinical relevance and landscape of the discussed gene targets.

Spheroid Formation and Peritoneal Metastasis in Ovarian Cancer: The Role of Stromal and Immune Components

Ovarian cancer (OC) is one of the most common gynecological cancers, with the worst prognosis and the highest mortality rate. Peritoneal dissemination (or carcinomatosis) accompanied by ascites formation is the most unfavorable factor in the progression and recurrence of OC. Tumor cells in ascites are present as either separate cells or, more often, as cell aggregates, i.e., spheroids which promote implantation on the surface of nearby organs and, at later stages, metastases to distant organs. Malignant ascites comprises a unique tumor microenvironment; this fact may be of relevance in the search for new prognostic and predictive factors that would make it possible to personalize the treatment of patients with OC. However, the precise mechanisms of spheroid formation and carcinomatosis are still under investigation. Here, we summarize data on ascites composition as well as the activity of fibroblasts and macrophages, the key stromal and immune components, in OC ascites. We describe current knowledge about the role of fibroblasts and macrophages in tumor spheroid formation, and discuss the specific functions of fibroblasts, macrophages and T cells in tumor peritoneal dissemination and implantation.

Tumor microenvironment manipulates chemoresistance in ovarian cancer (Review)

Ovarian cancer (OC) is the leading cause of mortality among the various types of gynecological cancer, and >75% of the cases are diagnosed at a late stage. Although platinum‑based chemotherapy is able to help the majority of patients to achieve remission, the disease frequently recurs and acquires chemoresistance, resulting in high mortality rates. The complexity of OC therapy is not solely governed by the intrinsic characteristics of the OC cells (OCCs) themselves, but is also largely dependent on the dynamic communication between OCCs and various components of their surrounding microenvironment. The present review attempts to describe the mutual interplay between OCCs and their surrounding microenvironment. Tumor‑associated macrophages (TAMs) and cancer‑associated fibroblasts (CAFs) are the most abundant stromal cell types in OC. Soluble factors derived from CAFs steadily nourish both the OCCs and TAMs, facilitating their proliferation and immune evasion. ATP binding cassette transporters facilitate the extrusion of cytotoxic molecules, eventually promoting cell survival and multidrug resistance. Extracellular vesicles fulfill their role as genetic exchange vectors, transferring cargo from the donor cells to the recipient cells and propagating oncogenic signaling. A greater understanding of the vital roles of the tumor microenvironment will allow researchers to be open to the prospect of developing therapeutic approaches for combating OC chemoresistance.

Doxorubicin-loaded, pH-sensitive Albumin Nanoparticles for Lung Cancer Cell Targeting

In recent decades, scientific and medical communities have continuously sought new methods and chemistries to improve the treatment of cancer. Among many types of nanoparticles considered as carriers for drug delivery, the protein ones count among the safest. The present study aimed to investigate the physicochemical and biological effects of the supplementation of albumin nanoparticles with doxorubicin (DOX). DOX was co-precipitated with albumin in a desolvation process and entrapped inside the cross-linked albumin nanoparticles, where it disrupted the protein structure at various levels: (a) it reduced the particle size distribution homogeneity; (b) it extended the peptide bond length; (c) it lowered the thermal stability of albumin; (d) it lowered the crystallinity of the protein. Physicochemical mechanisms underlying these changes are discussed. The drug release was incomplete under the physiological conditions, but the nanoparticles fully released their chemotherapeutic payload when pH was decreased by a single unit from the physiological value. Because the extracellular pH of tumors is usually by a single pH unit lower than that of healthy tissues, this environmentally responsive drug delivery system composed of albumin nanoparticles may be applicable in the targeting of cancer cells. In vitro assays against human lung cancer cells demonstrated that DOX released from albumin nanoparticles had a four times higher apoptotic activity than the equivalent concentration of free DOX. The ability of albumin to prevent the agglomeration of partially hydrophobic DOX and release it at a sustained, zero-order rate over the first 12 h of incubation, with no burst effect, explains this ability to augment the activity of DOX against the lung cancer cells.

Personalized models of heterogeneous 3D epithelial tumor microenvironments: Ovarian cancer as a model

Intractable human diseases such as cancers, are context dependent, unique to both the individual patient and to the specific tumor microenvironment. However, conventional cancer treatments are often nonspecific, targeting global similarities rather than unique drivers. This limits treatment efficacy across heterogeneous patient populations and even at different tumor locations within the same patient. Ultimately, this poor efficacy can lead to adverse clinical outcomes and the development of treatment-resistant relapse. To prevent this and improve outcomes, it is necessary to be selective when choosing a patient's optimal adjuvant treatment. In this review, we posit the use of personalized, tumor-specific models (TSM) as tools to achieve this remarkable feat. First, using ovarian cancer as a model disease, we outline the heterogeneity and complexity of both the cellular and extracellular components in the tumor microenvironment. Then we examine the advantages and disadvantages of contemporary cancer models and the rationale for personalized TSM. We discuss how to generate precision 3D models through careful and detailed analysis of patient biopsies. Finally, we provide clinically relevant applications of these versatile personalized cancer models to highlight their potential impact. These models are ideal for a myriad of fundamental cancer biology and translational studies. Importantly, these approaches can be extended to other carcinomas, facilitating the discovery of new therapeutics that more effectively target the unique aspects of each individual patient's TME. STATEMENT OF SIGNIFICANCE: In this article, we have presented the case for the application of biomaterials in developing personalized models of complex diseases such as cancers. TSM could bring about breakthroughs in the promise of precision medicine. The critical components of the diverse tumor microenvironments, that lead to treatment failures, include cellular- and extracellular matrix- heterogeneity, and biophysical signals to the cells. Therefore, we have described these dynamic components of the tumor microenvironments, and have highlighted how contemporary biomaterials can be utilized to create personalized in vitro models of cancers. We have also described the application of the TSM to predict the dynamic patterns of disease progression, and predict effective therapies that can produce durable responses, limit relapses, and treat any minimal residual disease.

Extracellular vesicles derived from ascitic fluid enhance growth and migration of ovarian cancer cells

Ovarian cancer is associated with a high mortality rate due to diagnosis at advanced stages. Dissemination often occurs intraperitoneally within the ascites fluid. The microenvironment can support dissemination through several mechanisms. One potential ascites factor which may mediate dissemination are EVs or extracellular vesicles that can carry information in the form of miRNAs, proteins, lipids, and act as mediators of cellular communication. We present our observations on EVs isolated from ascitic supernatants from patients diagnosed with high grade serous ovarian carcinoma in augmenting motility, growth, and migration towards omental fat. MicroRNA profiling of EVs from malignant ascitic supernatant demonstrates high expression of miR 200c-3p, miR18a-5p, miR1246, and miR1290 and low expression of miR 100- 5p as compared to EVs isolated from benign ascitic supernatant. The migration of ovarian cancer spheroids towards omental fat is enhanced in the presence of malignant ascitic EVs. Gene expression of these cells showed increased expression of ZBED2, ZBTB20, ABCC3, UHMK1, and low expression of Transgelin and MARCKS. We present evidence that ovarian ascitic EVs increase the growth of ovarian cancer spheroids through miRNAs.

Targeting the tumour microenvironment in platinum-resistant ovarian cancer

Ovarian cancer typically presents at an advanced stage, and although the majority of cases initially respond well to platinum-based therapies, chemoresistance almost always occurs leading to a poor long-term prognosis. While various cellular autonomous mechanisms contribute to intrinsic or acquired platinum resistance, the tumour microenvironment (TME) plays a central role in resistance to therapy and disease progression by providing cancer stem cell niches, promoting tumour cell metabolic reprogramming, reducing chemotherapy drug perfusion and promoting an immunosuppressive environment. As such, the TME is an attractive therapeutic target which has been the focus of intense research in recent years. This review provides an overview of the unique ovarian cancer TME and its role in disease progression and therapy resistance, highlighting some of the latest preclinical and clinical data on TME-targeted therapies. In particular, it focuses on strategies targeting cancer-associated fibroblasts, tumour-associated macrophages, cancer stem cells and cancer cell metabolic vulnerabilities.

Relationship between ascites volume and clinical outcomes in epithelial ovarian cancer

OBJECTIVE

Ascites is a tumor microenvironment, ascites and massive ascites-induce compression could promote the progression of epithelial ovarian cancer (EOC); however, the impact of ascites volume on clinical outcomes has not been studied extensively. We aimed to investigate the association between ascites volume and clinical outcomes especially platinum resistance in EOC.

METHODS

We retrospectively evaluated a total of 546 EOC patients with respect to the amount of ascites, clinicopathologic factors, and survival. Using the threshold of 1500 ml to classify patients into small- and large-volume ascites groups, we analyzed the correlation between ascites volume and clinicopathological factors, including platinum-free interval (PFI), and prognosis.

RESULTS

Patients with large volume ascites were more likely to present with later stage disease, primary platinum-resistant (PPR) cancer, and suboptimal cytoreduction. Prolonged PFI was associated with decreased ascites volume. The large-volume ascites group showed worse progression-free survival (PFS) and overall survival (OS). An increase in ascites volume was associated with an increased risk of disease recurrence (hazard ratio [HR] = 1.115, 95% confidence interval [CI]: 1.035-1.200) and death (HR = 1.213, 95% CI: 1.090-1.350).

CONCLUSIONS

Ascites was an independent predictor of PFS and OS in EOC patients. A large volume of ascites predicated a shortened PFI, an increased incidence of PPR and suboptimal cytoreduction. Thus, the volume of ascites is a simply available clinical parameter, which could be used to evaluate the prognosis and platinum resistance of EOC patients early, it contributes to formulate individualized treatment plan and improve the outcome of EOC patients.

microRNA-137 downregulates MCL1 in ovarian cancer cells and mediates cisplatin-induced apoptosis

Aim: miR-137 is downregulated in various cancers; however, its function in ovarian cancer remains unclear. Methods: The roles of miR-137 in apoptosis were accessed through IC₅₀ values and DAPI assay. The regulation of MCL1 by miR-137 was investigated through luciferase reporter assay and immunoblot. Results: miR-137 mimic could decrease the IC₅₀ value of cisplatin and promote apoptosis in OVCAR3 ovarian cancer cells. Using luciferase assay, results on a panel of anti-apoptotic proteins, we identified MCL1 as a target for miR-137 and the results were confirmed using immunoblot. Finally, the underlying pathway in which miR-137 may be involved was investigated by transcriptome sequencing. Conclusion: These results suggest that miR-137 downregulates MCL1 in ovarian cancer cells and mediates cisplatin-induced apoptosis.

Organoid of ovarian cancer: genomic analysis and drug screening

Ovarian cancer is the most common malignant tumors of the female reproductive system, and its standard treatments are cytoreductive surgery and platinum-based adjuvant chemotherapy. Great advances have been achieved in novel treatment strategies, including targeted therapy and immunotherapy. However, ovarian cancer has the highest mortality rate among gynecological tumors due to therapeutic resistance and the gap between preclinical data and actual clinical efficacy. Organoids are a 3D culture model that markedly affects gene analysis, drug screening, and drug sensitivity determination of tumors, especially when used in targeted therapy and immunotherapy. In addition, organoid can lead to advances in the preclinical research of ovarian cancer due to its convenient cultivation, good genetic stability, and high homology with primary tumors.

Dextran-Curcumin Nanoparticles as a Methotrexate Delivery Vehicle: A Step Forward in Breast Cancer Combination Therapy

With the aim to effectively deliver methotrexate (MTX) to breast cancer cells, we designed a nanocarrier system (DC) derived from the self-assembly of a dextran-curcumin conjugate prepared via enzyme chemistry with immobilized laccase acting as a solid biocatalyst. Nanoparticles consisted of homogeneously dispersed nanospheres with a mean diameter of 290 nm, as characterized by combined transmission electron microscopy and dynamic light scattering investigations. DC was able to control the MTX release overtime (t_1/2 value of 310 min), with cell internalization studies proving its presence inside MCF-7 cytoplasm. Finally, improved MTX efficacy was obtained in viability assays, and attributed to the synergy of curcumin moieties and loaded MTX as underlined by a combination index (CI) < 1.

Improving breast cancer therapy using doxorubicin loaded solid lipid nanoparticles: Synthesis of a novel arginine-glycine-aspartic tripeptide conjugated, pH sensitive lipid and evaluation of the nanomedicine in vitro and in vivo

Breast cancer is the leading cause of cancer mortality in women worldwide. To overcome the toxic side effects and multidrug resistance (MDR) during doxorubicin (DOX) chemotherapy, an arginine-glycine-aspartic (RGD) tripeptide modified, pH-sensitive solid lipid nanoparticles (SLNs) is employed in this study. In this study, a RGD conjugated, pH sensitive lipid was synthesized using glycerin monostearate (GMS) and adipic acid dihydrazide (HZ) as lipid materials and named RGD-HZ-GMS. RGD-HZ-GMS was applied to encapsulate DOX to construct a RGD modified, DOX loaded SLNs (RGD-DOX-SLNs). To evaluate the anticancer effect of RGD-DOX-SLNs, breast cancer cell line (MCF-7 cells) and DOX resistant cell line (MCF-7/ADR cells) were used. in vivo tumor suspension and toxicity effects were evaluated on mice bearing MCF-7/ADR cells breast cancer model. RGD-DOX-SLNs had a uniformly spherical shape. The mean particle size and zeta potential of the RGD-DOX-SLNs was 96.3 nm and 35.6 mV, respectively. RGD-DOX-SLNs showed 5.58 fold higher area under the plasma concentration - time curve (AUC) compared with DOX solution. Terminal half life (T_1/2) and peak concentration (C_max) of RGD-DOX-SLNs was 10.85 h and 39.12 ± 2.71 L/kg/h. in vitro and in vivo antitumor results indicate that RGD-DOX-SLNs might be a promising novel lipid carrier which could improve breast cancer therapy.

ATP-binding Cassette Transporters Substantially Reduce Estimates of ALDH-positive Cancer Cells based on Aldefluor and AldeRed588 Assays

Aldehyde dehydrogenase (ALDH) assays measure the accumulated fluorescence of enzyme products. However, cancer cells frequently co-express ALDH and ATP-binding cassette (ABC) transporters, which might mediate efflux of ALDH assay reagents. We demonstrate expression of active multidrug resistance protein1 (MDR1), multidrug resistance-associated protein (MRP), and breast cancer resistance protein (BCRP) in CT26 cancer cells as well as expression of MRP and BCRP in HT29 cancer cells. Without transporter inhibition, only small portions of both cell types were estimated to be ALDH-positive based on Aldefluor and AldeRed588 assays. However, MK-571 (MRP inhibitor) and novobiocin (BCRP inhibitor) substantially increased the rate of ALDH-positive CT26 cells based on either Aldefluor or AldeRed588 assays. Verapamil (MDR inhibitor) did not influence assay results. MK-571 also substantially increased the rate of ALDH-positive HT29 cells. Limiting dilution assays demonstrated greater numbers of tumor-spheres formed by Aldefluor-positive compared to -negative CT26 cells selected in the presence of MK-571 or novobiocin but not in their absence. These results reveal that Aldefluor and AldeRed588 products are efficient substrates for MRP- and BCRP-mediated efflux and substantially reduce estimated ALDH positivity rates in cancer cells. These findings demonstrate that complete blockade of these transporters is important to ensure accurate ALDH assay results and to develop newer assay techniques.

Lung cancer therapy using doxorubicin and curcumin combination: Targeted prodrug based, pH sensitive nanomedicine

Lung cancer is the leading cause of cancer death worldwide. To overcome the toxic side effects and multidrug resistance (MDR) during doxorubicin (DOX) chemotherapy, a urokinase plasminogen activator receptor (uPAR) targeting U11 peptide decorated, pH-sensitive, dual drugs co-encapsulated nanoparticles (NPs) system is employed in this study. A U11 peptide conjugated, pH-sensitive DOX prodrug (U11-DOX) was synthesized and used as materials to produce NPs. A curcumin (CUR) and U11-DOX co-encapsulated NPs system (U11-DOX/CUR NPs) was constructed to treat lung cancer. After the characterization of biophysical properties of this NPs system, synergistic chemotherapeutic efficacy was evaluated in both cultured cancer cells and tumor-bearing animal model. U11-DOX/CUR NPs had a uniformly spherical shape with a core-shell structure. The mean particle size and zeta potential of the U11-DOX/CUR NPs was 121.3 nm and -33.5 mV, with a DOX and CUR EE of 81.7 and 90.5%, respectively. The DOX release from U11-DOX/CUR NPs was 83.5, 55.2, and 32.8% correspondence to the pH of 5.0, 6.0 and 7.4. Cellular uptake efficiency of U11-DOX/CUR NPs was significantly higher than non U11 peptide decorated DOX/CUR NPs. U11-DOX/CUR NPs displayed a pronounced synergy effects in vitro and an obvious tumor tissue accumulation efficiency in vivo. In vivo antitumor experiment showed that U11-DOX/CUR NPs could inhibit the tumor growth to a level of 85%.In vitro and in vivo studies demonstrated that U11-DOX/CUR NPs is a sustained released, pH responsive, synergistic antitumor system. This study suggests that the U11-DOX/CUR NPs have promising potential for combination treatment of lung cancer.

Activation of LXRɑ/β by cholesterol in malignant ascites promotes chemoresistance in ovarian cancer

Background

The purpose of this study was to investigate the role of malignant ascites tumor microenvironment in ovarian cancer progression and chemoresistance.

Methods

A total of 45 patients with ovarian cancer and three benign ascites were collected at the time of clinical intervention. Ascites cholesterol levels were quantitated using cholesterol quantitation kit and recurrence free survival (RFS) of ovarian cancer patients were collected. The sensitivity of ovarian cancer cells to cisplatin (CDDP) and paclitaxel (PAC) were assessed by viability assay, flow cytometry and protein expression. Receiver operating characteristics (ROC) curve and Youden index analysis were applied to calculate the optimal cut-off values for ascites cholesterol. Kaplan-Meier curve were applied to compare RFS between high and low ascites cholesterol levels in ovarian cancer patients.

Results

Here we show that cholesterol is elevated in malignant ascites and modulates the sensitivity of ovarian cancer cells to CDDP and PAC by upregulating the expression of drug efflux pump proteins, ABCG2 and MDR1, together with upregulation of LXRɑ/β, the cholesterol receptor. Transfection of LXRɑ/β siRNA inhibited cholesterol-induced chemoresistance and upregulation of MDR1. In addition, the cholesterol level in malignant ascites was negatively correlated with number of CDDP-induced apoptotic cell death, but not with that of PAC-induced apoptotic cell death. Cholesterol depletion by methyl beta cyclodextrin (MβCD) inhibited malignant ascites-induced chemoresistance to CDDP and upregulation of MDR1 and LXRɑ/β. For patients with ovarian cancer, high cholesterol level in malignant ascites correlated with short RFS.

Conclusions

High cholesterol in malignant ascites contributes to poor prognosis in ovarian cancer patients, partly by contributing to multidrug resistance through upregulation of MDR1 via activation of LXRɑ/β.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5152-5) contains supplementary material, which is available to authorized users.

Review: Mechanotransduction in ovarian cancer: Shearing into the unknown

Ovarian cancer remains a deadly diagnosis with an 85% recurrence rate and a 5-year survival rate of only 46%. The poor outlook of this disease has improved little over the past 50 years owing to the lack of early detection, chemoresistance and the complex tumor microenvironment. Within the peritoneal cavity, the presence of ascites stimulates ovarian tumors with shear stresses. The stiff environment found within the tumor extracellular matrix and the peritoneal membrane are also implicated in the metastatic potential and epithelial to mesenchymal transition (EMT) of ovarian cancer. Though these mechanical cues remain highly relevant to the understanding and treatment of ovarian cancers, our current knowledge of their biological processes and their clinical relevance is deeply lacking. Seminal studies on ovarian cancer mechanotransduction have demonstrated close ties between mechanotransduction and ovarian cancer chemoresistance, EMT, enhanced cancer stem cell populations, and metastasis. This review summarizes our current understanding of ovarian cancer mechanotransduction and the gaps in knowledge that exist. Future investigations on ovarian cancer mechanotransduction will greatly improve clinical outcomes via systematic studies that determine shear stress magnitude and its influence on ovarian cancer progression, metastasis, and treatment.

HE4 level in ascites may assess the ovarian cancer chemotherapeutic effect

BACKGROUND

The clinical treatment of ovarian cancer with ascites is problematic. The main reasons for treatment failure are the susceptibility to intraperitoneal metastasis and chemotherapeutic drug resistance. The purpose and significance of this study is to evaluate which marker might evaluate treatment efficacy and improve the cure rate.

RESULTS

This study compared a no chemotherapy group with a chemotherapy group regarding the determination of carbohydrate antigen 125 and human epididymis protein 4 in ovarian cancer ascitic supernatants and cross-analyzed routine serum carbohydrate antigen 125 levels. The level of human epididymis protein 4 in the ascites of the chemotherapy group was significantly lower than that of the no chemotherapy group (p < 0.001). Moreover, the expression of ascitic human epididymis protein 4 correlated positively with serum carbohydrate antigen 125 levels (p < 0.001). MDR was positive in 13 of the 30 samples (43.33%) in the chemotherapy group with highly expressed CA125.

CONCLUSION

The level of human epididymis protein 4 in ovarian cancer ascites may reflect the therapeutic effect of ovarian cancer patients, and a high level of human epididymis protein 4 might predict chemoresistance and the possibility of ascites formation. The determination of the expression of human epididymis protein 4 alone or combined with carbohydrate antigen 125 levels in both serum and ascites in ovarian cancer patients with ascites may have important significance for guiding and improving the treatment regimen.

Effect of combined inhibition of p110 alpha PI3K isoform and STAT3 pathway in ovarian cancer platinum-based resistance

Background

Ovarian cancer is associated with poor prognostic outcome due to late diagnosis and to intrinsic and acquired resistance to platinum-based chemotherapy in a large number of patients. This chemoresistance is acquired through the peritoneal and ascites microenvironment by several released factors, such as IL-6,. Preclinical studies have implicated the activation of PI3K pathway in chemoresistance, showing it to extend tumor cell survival and modulate multidrug resistance. We aimed to evaluate the implication of the p110 alpha PI3K subunit in ovarian cancer chemoresistance acquisition, and to evaluate whether the STAT3 pathway can mediate resistance to PI3K inhibitors through secretion of IL6.

Results

Human ovarian adenocarcinoma IGROV-1 and JHOC-5 cells cultured in ascites showed an increase in carboplatinum-based resistance. Level of chemoresistance was associated to IL6 concentration in ascites. Activation of PI3K/Akt, STAT and MAPK pathways was observed after IGROV-1 incubation with ascites and treatment with carboplatin. Neither IGROV-1 nor JHOC-5 cells exposed to ascites treated with additional IL-6 directed antibody showed any reversion of the chemoresistance.

Conclusion

IL6-related resistance was not abolished by the selective inhibition of PI3K alpha subunit coupled with the anti-IL6-receptor antibody tocilizumab. This dual inhibition requires further exploration in other ovarian cancer models such as clear cell carcinoma.

Intraperitoneal nanotherapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin

Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth and increasing survival of mice with metastatic ovarian cancer. Finally, three cycles of siRNA-mediated DJ-1 therapy in combination with a low dose of cisplatin completely eradicated ovarian cancer tumors from the mice, and there was no cancer recurrence detected for the duration of the study, which lasted 35 weeks.

lncRNAs are novel biomarkers for differentiating between cisplatin-resistant and cisplatin-sensitive ovarian cancer

Cisplatin-resistant ovarian cancer occurs in patients with ovarian cancer treated with cisplatin-based chemotherapy, which results in tumor progression during treatment, or recurrence of the tumor within 6 months of the treatment. It is vital that a novel biomarker for diagnosis, or an efficient therapeutic target of cisplatin-resistant ovarian is identified. Long non-coding (lnc)RNAs were determined to serve critical functions in a variety of distinct types of cancer, including ovarian cancer; however, there is limited knowledge regarding the differential expression levels of lncRNAs in cisplatin-resistant and cisplatin-sensitive ovarian cancer. Therefore, in the present study, the expression levels were determined for these cancer types. The lncRNA expression profile in cisplatin-resistant ovarian cancer was analyzed and compared with the results for cisplatin-sensitive ovarian cancer; gene ontology and pathway analysis demonstrated that the dysregulated lncRNAs participated in important biological processes. Subsequently, it was identified that these dysregulated lncRNAs were present in other ovarian cancer tissues and in SKOV3 ovarian cancer cells, as well as its cisplatin-resistant clone, SKOV3/CDDP. In addition, it was revealed that 8 lncRNAs (Enst0000435726, Enst00000585612, Enst00000566734, Enst00000453783, NR_023915, RP11_697E22.2, uc010jub.1 and tcons_00008505) were associated with cisplatin-resistant ovarian cancer. The present study may assist in improving understanding of the initiation and developmental mechanisms underlying cisplatin-resistant ovarian cancer, which could aid future studies in discovering potential biomarkers for diagnosis or therapeutic targets that may be used in clinical treatment.

Ascitic fluid from advanced ovarian cancer patients compromises the activity of receptor tyrosine kinase inhibitors in 3D cell clusters of ovarian cancer cells

Ovarian cancer patients in the advanced stages of the disease show clinical ascites, which is associated with a poor prognosis. There is limited understanding of the effect of ascitic fluid on ovarian cancer cells and their response to anticancer drugs. We investigated the antitumour effects of EGFR/Her-2 (canertinib) and c-Met (PHA665752) inhibitors in a 3D cell model of three ovarian cancer lines. Single and combined inhibitor treatments affected cell growth of OVCAR-5 and SKOV-3 cell lines but not OV-90 cell line. Growth reduction was correlated with the down expression of PCNA, EGFR, HER-2, c-MET, ERK and AKT and their phosphorylation status in cells in growth factor supplemented media. However, these effects were not re-producible in OVCAR-5 and SKOV-3 cell lines when they were exposed to ascitic fluid obtained from three ovarian cancer patients. Serum albumin and protein components in the ascitic fluids may reduce the cellular uptake of the inhibitors.

Vitronectin (Vn) glycosylation patterned by lectin affinity assays-A potent glycoproteomic tool to discriminate plasma Vn from cancer ascites Vn

Changes in glycosylation have been associated with human cancer, but their complexity poses an analytical challenge. Ovarian cancer is a major cause of death in women because of an often late diagnosis. At least one-third of patients presents ascites fluid at diagnosis, and almost all have ascites at recurrence. Vitronectin (Vn) is a multifunctional glycoprotein that is suggested to be implicated in ovarian cancer metastasis and is found within ascites. The present study evaluated the potential of using lectin affinity for characterizing the glycosylation pattern of Vn. Human Vn was purified from 1 sample of ovarian cancer ascites or a pool of plasma samples. Consistent findings were observed with both dot blot and lectin array assays. Based on a panel of 40 lectins, the lectin array revealed discriminant patterns of lectin binding to Vn glycans. Interestingly, almost all the highlighted interactions were found to be higher with Vn from ascites relative to the plasma counterpart. Also, the lectin array was able to discriminate profiles of lectin interactions (ConA, SNA-I, PHA-E, PHA-L) between Vn samples that were not evident using dot blot, indicating its high sensitivity. The model of ConA binding during thermal unfolding of Vn confirmed the higher accessibility of mannosylated glycans in Vn from ascites as monitored by turbidimetry. Thus, this study demonstrated the usefulness of lectins and the lectin array as a glycoproteomic tool for high throughput and sensitive analysis of glycosylation patterns. Our data provide novel insights concerning Vn glycosylation patterns in clinical specimens, paving the way for further investigations regarding their functional impact and clinical interest.

Personalized Medicine-Based Approach to Model Patterns of Chemoresistance and Tumor Recurrence Using Ovarian Cancer Stem Cell Spheroids

Purpose: Chemoresistant ovarian cancers grow in suspension within the ascites fluid. To screen the effect of chemotherapeutics and biologics on resistant ovarian cancers with a personalized basis, we developed a 3D hanging drop spheroid platform.Experimental Design: We initiated spheroids with primary aldehyde dehydrogenase-positive (ALDH⁺) CD133⁺ ovarian cancer stem cells (OvCSC) from different patient samples and demonstrated that stem cell progeny from harvested spheroids was similar to the primary tumor. OvCSC spheroids were utilized to initiate tumors in immunodeficient mice. Drug responses to cisplatin and ALDH-targeting compound or JAK2 inhibitor determined whether the OvCSC population within the spheroids could be targeted. Cells that escaped therapy were isolated and used to initiate new spheroids and model tumor reemergence in a personalized manner.Results: OvCSC spheroids from different patients exhibited varying and personalized responses to chemotherapeutics. Xenografts were established from OvCSC spheroids, even with a single spheroid. Distinct responses to therapy were observed in distinct primary tumor xenografts similar to those observed in spheroids. Spheroids resistant to cisplatin/ALDH inhibitor therapy had persistent, albeit lower ALDH expression and complete loss of CD133 expression, whereas those resistant to cisplatin/JAK2 inhibitor therapy were enriched for ALDH⁺ cells.Conclusions: Our 3D hanging drop suspension platform can be used to propagate primary OvCSCs that represent individual patient tumors effectively by differentiating in vitro and initiating tumors in mice. Therefore, our platform can be used to study cancer stem cell biology and model tumor reemergence to identify new targeted therapeutics from an effective personalized medicine standpoint. Clin Cancer Res; 23(22); 6934-45. ©2017 AACR.

Prediction of therapy response in ovarian cancer: Where are we now?

Therapy resistance is a major challenge in the management of ovarian cancer (OC). Advances in detection and new technology validation have led to the emergence of biomarkers that can predict responses to available therapies. It is important to identify predictive biomarkers to select resistant and sensitive patients in order to reduce important toxicities, to reduce costs and to increase survival. The discovery of predictive and prognostic biomarkers for monitoring therapy is a developing field and provides promising perspectives in the era of personalized medicine. This review article will discuss the biology of OC with a focus on targetable pathways; current therapies; mechanisms of resistance; predictive biomarkers for chemotherapy, antiangiogenic and DNA-targeted therapies, and optimal cytoreductive surgery; and the emergence of liquid biopsy using recent studies from the Medline database and ClinicalTrials.gov.

Quantitative evaluation of ABC transporter-mediated drug resistance based on the determination of the anticancer activity of camptothecin against breast cancer stem cells using TIRF

Total internal reflection fluorescence microscopy (TIRF) and Qdot probe based analytical method for the simultaneous evaluation of the cytotoxic ability of camptothecin and the drug resistance profile upon the inhibition of drug efflux pumps in breast cancer stem cells.