Project description:Although many genes associated with the development of resistance to chemotherapy are known, the mechanisms of their regulation are still poorly understood. One of the ways to regulate gene expression is regulation at mRNA level by small noncoding RNA particles – designated as a micro RNA (miRNA). Changes in miRNA expression were also observed in cell line studyes. Downregulation of miR-31 expression correlated with taxane resistance in ovarian cancer cell lines. In contrast upregulation of miR-98-5p was observed in cisplatin (CIS) -resistant cell lines. Changes in miRNAs expression were also noted in another cancers. miR-195 expression was downregulated in temozolomid-resistant glioma cells and miR-203 was downregulated in prostate cancer cells resistant to doxorubicin (DOX). The use of miRNA microarrays to analyse changes in miRNA gene expression is an effective molecular tool for the discovering new miRNA genes involved in drug resistance processes. The present study shows alterations in the miRNA expression levels in the CIS (W1CR), PAC (W1PR1 and W1PR2), DOX (W1DR), and topotecan (TOP) (W1TR) - resistant variants of W1 sensitive ovarian cancer cell line.
Project description:MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by targeting mRNAs and triggering either translation repression or RNA degradation. Emerging evidence suggests the potential involvement of altered regulation of miRNA in the pathogenesis of cancers, and these genes are thought to function as both tumor suppressors and oncogenes. Using microRNA microarrays, we identify several miRNAs aberrantly expressed in human ovarian cancer tissues and cell lines. miR-221 stands out as a highly elevated miRNA in ovarian cancer, while miR-21 and several members of the let-7 family are found downregulated. Public databases were used to reveal potential targets for the highly differentially expressed miRNAs. In order to experimentally identify transcripts whose stability may be affected by the differentially expressed miRNAs, we transfected precursor miRNAs into human cancer cell lines and used oligonucleotide microarrays to examine changes in the mRNA levels. Keywords: Expression data from various ovarian cancer cell lines transfected with pre-microRNA.
Project description:Conventional frontline treatment for ovarian cancer consists of successive chemotherapy cycles of paclitaxel and platinum. Despite the initial favorable responses for most patients, chemotherapy resistance frequently leads to recurrent or refractory disease. New treatment strategies that circumvent or prevent mechanisms of resistance are needed to improve ovarian cancer therapy. We developed in vitro ovarian cancer cell line models of acquired paclitaxel resistance using 2 immortalized human ovarian cancer cell lines, OVCAR3 and TOV-21G. We also developed in vitro primary ovarian cancer organoid models using tumor tissue from 7 patients with gynecologic malignancies. Gene expression differences in resistant and sensitive lines were analyzed by RNA sequencing to identify potential mechanisms of paclitaxel resistance in primary ovarian cancer.
Project description:Epithelial ovarian cancer (EOC) represents the gynecologic cancer with the highest mortality rate. Despite a high initial response to chemotherapy, the majority of patients with advanced EOC relapses and subsequently develops chemoresistance that results in treatment failure and death of the patient. AIM: we have generated an isogenic model of PT-resistance in a panel of 3 EOC cell lines. microRNA profiling was used to identify new molecular pathway that regulate chemoresistance.
Project description:Paired platinum-sensitive & platinum-resistant cell lines PEO1 and PEO4 (respectively) were derived from the same patient. Cell line cultures were profiled with the HT-HGU133a GeneChip to investigate chemotherapy resistance related expression of genes marked with different histone modifications in a primary ovarian tumour (clinical data for the primary ovarian tumour is available as Series supplementary file).
Project description:Comparison of various ovarian tumors and ovarian cell lines. Keywords: Various ovarian tumors and cell lines. Samples from ovarian tumors and ovarian cell lines were examined for their microRNA expression patterns.
Project description:Transcriptome profiling of matched ovarian cancer cell lines with in vivo platinum sensitivity and resistance by next-generation sequencing
Project description:We evaluated the genome-wide microRNA expression profiles in lymphoblastoid cell lines of familial ovarian cancer patients and controls We used microarray to perform microRNA profiling in lymphoblastoid cell lines from 74 women with familial ovarian cancer patients and 47 controls.
Project description:We evaluated the genome-wide microRNA expression profiles in lymphoblastoid cell lines of familial ovarian cancer patients and controls