Project description:The objective of this work was to identify potential cancer biomarkers by analyzing microarray and protein expression data from platinum-sensitive and -resistant ovarian cancer patient samples. The gene expression profiles of the samples were ompared based on platinum sensitivity status and PARP levels. Overall design: 6 clinical samples of platinum sensitive and 6 samples of resistant.
Project description:Ovarian cancer has the highest mortality rate of all gynecologic malignancies. Identification of new biomarkers is highly needed due to its late diagnosis and high recurrence rate. The objective of this study was to identify mechanisms of therapy resistance and potential biomarkers by analyzing mRNA and protein expression from samples derived from patients with platinum-sensitive and -resistant ovarian cancer (total cohort n?=?53). The data revealed new candidates for targeted therapies, such as GREB1 and ROR2. We showed that the development of platinum resistance correlated with upregulation of ROR2, whereas GREB1 was downregulated. Moreover, we demonstrated that high levels of ROR2 in platinum-resistant samples were associated with upregulation of Wnt5a, STAT3 and NF-kB levels, suggesting that a crosstalk between the non-canonical Wnt5a-ROR2 and STAT3/NF-kB signaling pathways. Upregulation of ROR2, Wnt5a, STAT3 and NF-kB was further detected in a platinum-resistant cell-line model. The results of the present study provided insight into molecular mechanisms associated with platinum resistance that could be further investigated to improve treatment strategies in this clinically challenging gynecological cancer.
Project description:Resistance to platinum-based chemotherapy is a clinical challenge in the treatment of ovarian cancer (OC) and limits survival. Therefore, innovative drugs against platinum-resistance are urgently needed. Our therapeutic concept is based on the conjugation of two chemotherapeutic compounds to a monotherapeutic pro-drug, which is taken up by cancer cells and cleaved into active cytostatic metabolites. Here, we explore the activity of the duplex-prodrug 5-FdU-ECyd, covalently linking 2'-deoxy-5-fluorouridine (5-FdU) and 3'-C-ethynylcytidine (ECyd), on platinum-resistant OC cells. RNA-Sequencing was used for characterization of 5-FdU-ECyd treated platinum-sensitive A2780 and isogenic platinum-resistant A2780cis. Overall design: Platinum-sensitive A2780 and platinum resistant-cells A2780cis were treated with 5−FdU−Ecyd for 6h and 12h, there are also 6h and 12h untreated controls, all groups are in triplicates
Project description:Resistance to platinum compounds represents a major obstacle to the cure of ovarian carcinoma. The molecular profiling of drug-sensitive and drug-resistant cells may be helpful to clarify if altered expression of miRNAs can contribute to the drug-resistant phenotype. The expression pattern of miRNAs of three ovarian carcinoma cell lines was examined. The analysis revealed the modulation of several miRNAs in the two platinum-resistant cell lines as compared to parental platinum-sensitive cells. The integration of the information obtained through miRNA expression analysis may be useful to clarify the specific molecular alterations of factors and pathway favouring survival of tumor cells. Overall design: To examine the expression patterns of miRNAs in platinum-sensitive cells versus platinum-resistant cells, we used three ovarian carcinoma cell lines: the parental cisplatin-sensitive IGROV-1 cell line, the platinum-resistant variants IGROV-1/Pt1, generated by exposure of parental cells to cisplatin and IGROV-1/OHP, obtained by exposure of parental cells to oxaliplatin. Three independent samples for each cell line were prepared. Exponentially growing cells were harvested using trypsin and counted. Cells were centrifuged and pellets (10 million cells/sample) were immediately frozen in liquid nitrogen. miRNAs were isolated and microarrays were run. Overall, nine samples were analysed consisting of three biological replicates for each cell line.
Project description:BACKGROUND:Eribulin mesylate is a tubulin inhibitor with activity superior to paclitaxel in NIH:OVCAR-3 human epithelial ovarian cancer xenograft models. In this study, the authors assessed the efficacy of eribulin in platinum-resistant and platinum-sensitive recurrent ovarian cancer. METHODS:Patients with recurrent, measurable epithelial ovarian cancer who had received ?2 prior cytotoxic regimens and who had adequate organ function were enrolled into 2 separate cohorts: 1) platinum-resistant patients (who had a progression-free interval <6 months after their last platinum-based therapy) and 2) platinum-sensitive patients (who had a progression-free interval ?6 months after their last platinum-based therapy). Eribulin 1.4 mg/m(2) was administered over 15 minutes intravenously on days 1 and 8 every 21 days. Efficacy was determined by objective response on computed tomography studies. RESULTS:In the platinum-resistant cohort, 37 patients enrolled, and 36 patients were evaluable for response and toxicity. Two patients achieved a partial response (5.5%), and 16 patients (44%) had stable disease as their best response. The median progression-free survival was 1.8 months (95% confidence interval, 1.4-2.8 months). In the platinum-sensitive cohort, 37 patients enrolled, and all were evaluable for response. Seven patients achieved a partial response (19%). The median progression-free survival was 4.1 months (95% confidence interval, 2.8-5.8 months). The major toxicity was grade 3 or 4 neutropenia (42% of platinum-resistant patients; 54% of platinum-sensitive patients). CONCLUSIONS:Eribulin produced an objective response in 5.5% of women with platinum-resistant, recurrent ovarian cancer and in 19% of women with platinum-sensitive disease. The median progression-free survival was 1.8 months in the platinum-resistant group and 4.1 months in the platinum-sensitive group.
Project description:Resistance to platinum compounds represents a major obstacle to the cure of ovarian carcinoma. The molecular profiling of drug-sensitive and drug-resistant cells may be helpful to clarify if altered gene expression can contribute to the drug-resistant phenotype. The expression pattern of three ovarian carcinoma cell lines was examined. The analysis revealed the modulation of several genes in the two platinum-resistant cell lines as compared to parental platinum-sensitive cells. The integration of the information obtained through gene expression analysis may be useful to clarify the specific molecular alterations of factors and pathway favouring survival of tumor cells. Overall design: To examine gene expression changes in platinum-sensitive cells versus platinum-resistant cells, we used three ovarian carcinoma cell lines: the parental cisplatin-sensitive IGROV-1 cell line, the platinum-resistant variants IGROV-1/Pt1, generated by exposure of parental cells to cisplatin and IGROV-1/OHP, obtained by exposure of parental cells to cisplatin. Three independent samples for each cell line were prepared. Exponentially growing cells were harvested using trypsin and counted. Cells were centrifuged and pellets (10 million cells/sample) were immediately frozen in liquid nitrogen. RNA was isolates and microarrays were run. Overall, nine samples were analysed consisting of three biological replicates for each cell line.
Project description:Ovarian cancer is characterized by an increase in cellular energy metabolism, which is predominantly satisfied by glucose and glutamine. Targeting metabolic pathways is an attractive approach to enhance the therapeutic effectiveness and to potentially overcome drug resistance in ovarian cancer. In platinum-sensitive ovarian cancer cell lines the metabolism of both, glucose and glutamine was initially up-regulated in response to platinum treatment. In contrast, platinum-resistant cells revealed a significant dependency on the presence of glutamine, with an upregulated expression of glutamine transporter ASCT2 and glutaminase. This resulted in a higher oxygen consumption rate compared to platinum-sensitive cell lines reflecting the increased dependency of glutamine utilization through the tricarboxylic acid cycle. The important role of glutamine metabolism was confirmed by stable overexpression of glutaminase, which conferred platinum resistance. Conversely, shRNA knockdown of glutaminase in platinum resistant cells resulted in re-sensitization to platinum treatment. Importantly, combining the glutaminase inhibitor BPTES with platinum synergistically inhibited platinum sensitive and resistant ovarian cancers in vitro. Apoptotic induction was significantly increased using platinum together with BPTES compared to either treatment alone. Our findings suggest that targeting glutamine metabolism together with platinum based chemotherapy offers a potential treatment strategy particularly in drug resistant ovarian cancer.
Project description:This case report describes the clinical course of a heavily pretreated patient enrolled on the Phase II QUADRUPLE THREAT clinical trial (NCT02489903) with recurrent metastatic epithelial ovarian cancer that was previously treated with a platinum doublet and that benefited from another reintroduction of a platinum doublet after a brief priming period with RRx-001. Platinum-taxane combination is the initial treatment of choice in ovarian cancer and the "go-to regimen" for patients with recurrent, platinum-sensitive disease. However, platinum resistance is an inevitable and uniformly fatal development. One of the "Holy Grails" in ovarian cancer, besides early detection, is to reverse this resistance and retreat with a platinum doublet regimen. Because of the correlation between therapeutic resistance and poor clinical outcomes, this case, which potentially demonstrates a new avenue of anticancer development in epithelial ovarian cancer provided it is repeatable with other ovarian patients, was felt to merit a report.
Project description:Although epithelial ovarian cancers (EOCs) are initially treated with platinum-based chemotherapy, EOCs vary in platinum responsiveness. Cataloging antineoplastic agents according to their effectiveness against platinum-resistant and platinum-sensitive EOC cell lines is valuable for development of therapeutic strategies to avoid platinum inefficacy and to exploit platinum sensitivity. TOV-21G devoid of FANCF expression, OV-90 and SKOV-3 were employed as examples of platinum-sensitive, platinum-intermediate and platinum-resistant cell lines, respectively. Antineoplastic agents examined included mitomycin C, doxorubicin, etoposide, gemcitabine, chlorambucil, paclitaxel, triapine and X-rays. Their effectiveness against cell lines was analyzed by clonogenic assays. Cytotoxic profiles of mitomycin C and carboplatin were similar, with mitomycin C exhibiting greater potency and selectivity against TOV-21G than carboplatin. Cytotoxic profiles of doxorubicin, etoposide and X-rays overlapped with that of carboplatin, while OV-90 overexpressing Rad51 was more resistant to chlorambucil than SKOV-3. The efficacy of paclitaxel and triapine was independent of platinum sensitivity or resistance. Consistent with these cytotoxic profiles, cisplatin/mitomycin C, triapine, and paclitaxel differed in the capacity to induce phosphorylation of H2AX, and produced unique inhibitory patterns of DNA/RNA syntheses in HL-60 human leukemia cells. Paclitaxel and triapine in combination produced additive antitumor effects in M109 murine lung carcinoma. In conclusion, mitomycin C is potentially more effective against Fanconi anemia pathway-deficient EOCs than carboplatin. Doxorubicin and etoposide, because of their overlapping cytotoxic properties with carboplatin, are unlikely to be efficacious against platinum-refractory EOCs. Paclitaxel and triapine are effective regardless of platinum sensitivity status, and promising in combination for both platinum-sensitive and platinum-refractory EOCs.
Project description:Targeting angiogenesis is proving to be a successful approach in the management of ovarian cancer. The vascular endothelial growth factor inhibitor, bevacizumab, is the first angiogenesis inhibitor to have shown a significant progression-free survival advantage in the Phase III setting. There is now evidence supporting the use of bevacizumab in combination with chemotherapy for first-line and relapsed (platinum-sensitive and resistant) ovarian cancer. In this review, we summarize the positive Phase III trial (OCEANS [Ovarian Cancer Study Comparing Efficacy and Safety of Chemotherapy and Anti-Angiogenic Therapy in Platinum-Sensitive Recurrent Disease]) that led to European Medicines Agency approval of bevacizumab in platinum-sensitive first relapse and discuss the best use of the drug in this disease.