Carboplatin-induced gene expression changes in vitro are prognostic of survival in epithelial ovarian cancer
ABSTRACT: We performed a time-course microarray experiment to define the transcriptional response to carboplatin in vitro, and to correlate this with clinical outcome in epithelial ovarian cancer (EOC). RNA was isolated from carboplatin and control-treated 36M2 ovarian cancer cells at several time points, followed by oligonucleotide microarray hybridization. Carboplatin induced changes in gene expression were assessed at the single gene as well as at the pathway level. Clinical validation was performed in publicly available microarray datasets using disease free and overall survival endpoints. Time-course and pathway analyses identified 317 genes and 40 pathways (designated time-course and pathway signatures) deregulated following carboplatin exposure. Both types of signatures were validated in two separate platinum-treated ovarian and NSCLC cell lines using published microarray data. Expression of time-course and pathway signature genes distinguished between patients with unfavorable and favorable survival in two independent ovarian cancer datasets. Among the pathways most highly induced by carboplatin in vitro, the NRF2, NF-kB, and cytokine and inflammatory response pathways were also found to be upregulated prior to chemotherapy exposure in poor prognosis tumors. Overall design: we treated the 36M2 cell line with carboplatin 100μM or vehicle-control for 24hrs and cells were harvested and processed for RNA isolation at 24, 30 and 36hrs after treatment.
Project description:We performed a time-course microarray experiment to define the transcriptional response to carboplatin in vitro, and to correlate this with clinical outcome in epithelial ovarian cancer (EOC). RNA was isolated from carboplatin and control-treated 36M2 ovarian cancer cells at several time points, followed by oligonucleotide microarray hybridization. Carboplatin induced changes in gene expression were assessed at the single gene as well as at the pathway level. Clinical validation was performed in publicly available microarray datasets using disease free and overall survival endpoints. Time-course and pathway analyses identified 317 genes and 40 pathways (designated time-course and pathway signatures) deregulated following carboplatin exposure. Both types of signatures were validated in two separate platinum-treated ovarian and NSCLC cell lines using published microarray data. Expression of time-course and pathway signature genes distinguished between patients with unfavorable and favorable survival in two independent ovarian cancer datasets. Among the pathways most highly induced by carboplatin in vitro, the NRF2, NF-kB, and cytokine and inflammatory response pathways were also found to be upregulated prior to chemotherapy exposure in poor prognosis tumors. Experiment Overall Design: we treated the 36M2 cell line with carboplatin 100μM or vehicle-control for 24hrs and cells were harvested and processed for RNA isolation at 24, 30 and 36hrs after treatment.
Project description:Carboplatin and paclitaxel are the most widely prescribed chemotherapeutic agents for ovarian cancer. Not all patients respond to treatment, so there is a need for biomarkers that reliably predict resistance in ovarian tumors. Expression of such biomarkers may be dynamically controlled. Gene expression was assessed for a period of 14 days after treatment with carboplatin or combined carboplatin-paclitaxel in xenografts from two ovarian cancer models: chemosensitive serous adenocarcinoma derived OV1002 and slow growing, chemoresistant HOX424 of clear cell origin. Tumour volume reduction was observed in both cell lines post treatment, with a more prominent effect in OV1002, which subsided in late time points. In OV1002, hierarchical clustering classified differentially expressed genes into four time-related patterns, upregulated and downregulated groups for each early and late expressed genes. Upregulated genes were involved in DNA repair, cell cycle and apoptosis, while downregulated groups were involved in oxygen consuming metabolic processes and apoptosis control. Carboplatin-paclitaxel treatment triggered a more comprehensive response. HOX424 responded only to the combined treatment, while the observed reduction in tumour growth was limited. Several apoptosis and cell cycle genes were upregulated, while Wnt signaling was downregulated in the exclusively late expression pattern observed in this cell line. Late downregulated gene groups post carboplatin-taxane treatment were capable of predicting overall survival in two independent clinical datesets. Pathways overrepresented in these clusters were also predictive of outcome. This longitudinal gene expression study may help characterization of chemotherapy response, identification of resistance biomarkers and guiding timing of biopsies. 101 samples from 2 cell lines, untreated, carboplatin (Carbo) treated, carboplatin-paclitaxel (Carbotax) treated, over 5 time points (days 1,2,4,7,14)
Project description:The recently developed COXEN method (PMID: 17666531) has been used to successfully extrapolate gene signatures of drug sensitivity across different tumor histotypes. We wanted to explore the utility of COXEN to predict chemosensitivity in canine cancer, specifically if we could extrapolate gene signatures identified in human datasets over to canine osteosarcoma tumors. This dataset of canine osteosarcoma tumor samples has available clinical outcome data after patients had infected limbs amputated and were treated with doxorubicin and/or carboplatin. We performed microarray analysis on this panel of tumor samples for validating our COXEN prediction models for doxorubicin or carboplatin sensitivity. Chemotherapy naive primary tumors were collected at the time of amputation and archived at the Flint Animal Cancer Center. RNA was extracted from 33 frozen archived tumor samples, followed by microarray analysis. The gene expression data was RMA preprocessed, scaled and were used as a independent test set to evaluate developed prediction models of sensitivity to doxorubicin or carboplatin. Drug predictions were than compared to clinical outcome in these patients that received doxorubicin and/or carboplatin.
Project description:Background: Current protocols for the treatment of ovarian cancer include combination chemotherapy with a platinating agent and a taxane. However, many patients experience relapse of their cancer and the development of drug resistance is not uncommon, making successful second line therapy difficult to achieve. The objective of this study was to develop a cell line resistant to both carboplatin and docetaxel (dual drug resistant ovarian cell line A2780CBNDXL), along with single agent resistant lines (docetaxel resistant A2780DXL and carboplatin resistant A2780CBN), to investigate the mechanisms which underlie the development of dual drug resistance. Methods: The A2780 epithelial ovarian cancer cell line was used to select for isogenic carboplatin, docetaxel and dual drug resistant cell lines. A selection method of gradually increasing drug doses was implemented to avoid clonal selection. Resistance was confirmed using a clonogenic assay. Changes in gene expression associated with the development of drug resistance were determined by microarray analysis compared to parental co-culture control A2780CC. Changes in selected genes were validated by QPCR and immunoblotting. Results: Three isogenic cell lines were developed and resistance to each drug or the combination of drugs was confirmed. Development of resistance was accompanied by a reduced growth rate. The microarray and QPCR analyses showed that unique changes in gene expression occurred in the dual drug resistant cell line and that genes known to be involved in resistance could be identified in all cell lines. Conclusions: Novel changes in gene expression can occur in the development of dual drug resistance, indicating that dual drug resistance is not a simple combination of the changes occurring in single agent resistance Carboplatin, docetaxel (GSE26129) and carboplatin/docetaxel dual resistant cell lines of ovarian A2780 were generated for gene expression profilling. Two colour microarray of Agilent whole human genome nucleotide arrays was conducted with two replicate of both forward and reverse labellings for each cell line. Four arrays were used for this experiments. And it was four replicate of both forward and reverse labellings for A2780 cells. Eight arrays were used for this experiments
Project description:The patient-derived xenograft (PDX) model retains the heterogeneity of patient tumors, allowing a means to not only examine efficacy of a therapy across a population, but also study crucial aspects of cancer biology in response to treatment. Herein we describe the development and characterization of an ovarian-PDX model in order to study the development of chemoresistance. We demonstrate that PDX tumors are not simply composed of tumor-initiating cells, but recapitulate the original tumor’s heterogeneity, oncogene expression profiles, and clinical response to chemotherapy. Combined carboplatin/paclitaxel treatment of PDX tumors enriches the cancer stem cell populations, but persistent tumors are not entirely composed of these populations. RNA-Seq analysis of treated PDX tumors compared to untreated tumors demonstrates a consistently contrasting genetic profile after therapy, suggesting similar, but few, pathways are mediating chemoresistance. The pathways most significantly altered included Protein Kinase A signaling, GNRH signaling, and sphingosine-1-phosphate signaling. Pathways and genes identified by this methodology represent novel approaches to targeting the chemoresistant population in ovarian cancer 6 pairs of Patient-Derived Xenografts (PDX) were ananlyzed using RNA-seq for a total of 12 samples. Each pair consists of a treated and untreated PDX of ovarian cancer. Treated Ovarian cancer PDXs were treated with 4 weeks of a combination of carboplatin and taxol. RNA was isolated and converted to cDNA. RNA-seq was conductred on the Illumina HiSeq 2000 with 50 bp paired end sequencing
Project description:All patients with suspected ovarian cancer (Raised CA 125 and a complex pelvic mass in a perimenopausal woman) were radiologically staged using CT scan and a chest x-ray. Patients with evidence of intra-abdominal metastasis and/or malignant pleural effusion were approached for entry to the study. Tissue biopsy was obtained either under radiological control (core needle biopsy) or via laparoscopic surgery (punch biopsy). Patients with histologicaly confirmed epithelial ovarian cancer were randomized to receive either three cycles of carboplatin (AUC 7) or paclitaxel (175 mg/m2). Overall design: Patients with suspected ovarian cancer had a biopsy obtained before and after 3 cycles of either Carboplatin or Paclitaxel.
Project description:summary Ovarian cancer is the leading cause of death among gynecologic malignancies. This is partly due to a non-durable response to chemotherapy. Prediction of resistance to chemotherapy could be a key role in more personalized treatment. In the current study we aimed to examine if microRNA based predictors could predict resistance to chemotherapy in ovarian cancer, and to investigate if the predictors could be prognostic factors for progression free and overall survival. Methods Predictors of chemotherapy-resistance were developed based on correlation between miRNA expression and differences in measured growth inhibition in a variety of human cancer cell lines in the presence of Carboplatin, Paclitaxel and Docetaxel (deposited under accession number E-MTAB-327 in the ArrayExpress database of the European Bioinformatics Institute, 2012). These predictors were then, retrospectively, blindly validated in a cohort of 170 epithelial ovarian cancer patients treated with Carboplatin and Paclitaxel or Docetaxel as first line treatment. Results In a multivariate cox proportional analysis the predictors of chemotherapy-resistance were not able to predict time to progression after end of chemotherapy (hazard ratio: 0.64, 95% CI: 0.36 – 1.12, P=0.117). However, in a multivariate logistic analysis, where time to progression was considered as either more or less than 6 months, the predictors match clinical observed chemotherapy-resistance (odds ratio: 0.19, 95% CI: 0.05-0.73, P=0.015). Neither univariate nor multivariate, time-dependent, cox analysis for progression free survival (PFS) or overall survival (OS) in all 170 patients showed to match predicted resistance to chemotherapy (PFS: hazard ratio: 0.69, 95% CI: 0.40-1.19, P=0.183, OS: hazard ratio: 0.76, 95% CI: 0.42-1.40, P=0.386). Conclusion In the current study, microRNA based predictors of chemotherapy-resistance did not demonstrate any convincing correlation to clinical observed chemotherapy-resistance, progression free survival, or overall survival, in patients with epithelial ovarian cancer. However the predictors did reflect relapse more or less than 6 months. Overall design: A total of 198 epithelial ovarian cancer patients were analyzed for miRNA expression. Of these, detailed clinical information were available for 170 patients. Predictors of chemotherapy-resistance were developed based on correlation between miRNA expression and differences in measured growth inhibition in a variety of human cancer cell lines in the presence of Carboplatin, Paclitaxel and Docetaxel. These predictors were then, retrospectively, blindly validated in the cohort of 170 epithelial ovarian cancer patients treated with Carboplatin and Paclitaxel or Docetaxel as first line treatment. Under EU data protection legislation it is a violation of patient privacy to publish de-identified individual patient information. Therefore, clinical data (eg, chemotherapy-resistance, progression free survival, or overall survival discussed in the summary etc.) were not provided.
Project description:Epigenetic changes, particularly DNA methylation aberrations have been implicated in acquired resistance to platinum in ovarian cancer. A multi-institutional randomized clinical trial compared a regimen of a DNA methyl transferase (DNMT) inhibitor guadecitabine and carboplatin to physician’s choice chemotherapy for patients with recurrent platinum resistant ovarian cancer. Tumor biopsies or malignant ascites were collected at day 1 of cycle 1 (pre-guadecitabine) and after two cycles of treatment (post-decitabine). The goal of the current study was to analyze guadecitabine-induced DNA methylation and gene expression changes and correlate pretreatment levels with clinical outcomes. Epigenomic and transcriptomic profiling using the Infinium HumanMethylation450 BeadChip (HM450) and RNA sequencing revealed extensive methylation and gene expression changes induced by guadecitabine in ovarian tumors. Ninety-four gene promoters were significantly hypomethylated after treatment with guadecitabine and 949 genes were differentially expressed in pre vs. post-treatment tumors. Pathways associated with immune reactivation and DNA repair were significantly altered by guadecitabine treatment. Expression levels of 1155 genes involved in 25 networks on day 1 of cycle 1 correlated with progression free survival. Increased expression of selected genes (e.g. DOK2, miR193a) silenced through promoter methylation restored platinum sensitivity in ovarian cancer cells. Together, these results support that guadecitabine altered DNA methylation and expression of genes and gene networks correlate with re-sensitization to carboplatin in ovarian cancer patients. Overall design: 146 samples are analyzed, including tumor, ascites samples collected from patients with platinum resistant ovarian cancer before and after treated by guadecitabine, as well as HOSE (human normal ovarian surface epithelium cells), used as normal control
Project description:High grade serous ovarian cancers (HGSC) are deadly malignancies that relapse despite carboplatin chemotherapy. Here we show that 16 independent primary HGSCs contain a CA125 negative population enriched for carboplatin resistant cancer initiating cells. Transcriptome analysis reveals up-regulation of homologous recombination DNA repair and anti-apoptotic signals in this population. While treatment with carboplatin enriches for CA125 negative cells, co-treatment with carboplatin and birinapant eliminates these cells in HGSCs expressing high levels of the inhibitor of apoptosis protein cIAP in the CA125 negative population. Birinapant sensitizes CA125 negative cells to carboplatin by mediating degradation of cIAP causing cleavage of caspase-8 and restoration of apoptosis. This co-therapy significantly improved disease free survival in vivo compared to either therapy alone in tumor-bearing mice. These findings suggest that therapeutic strategies that target CA125 negative cells may be useful in the treatment of HGSC. mRNA profiles of CA125 positive and negative populations, generated by next generation sequencing of populations FACS isolated from 10 independent dissociated primary human high grade serous ovarian cancers, were compared.