An integrative network biology analysis identifies miR-508-3p as the determinant and a prognosis biomarker of the mesenchymal subtype ovarian cancer
ABSTRACT: Recently, several research groups have identified the mesenchymal subtype of serous OvCa on the basis of transcriptome data and its potential correlation with poor prognosis. We set out to define the regulatory mechanisms underlying the distinct gene expression profiles of serous OvCa using a network-based approach involving multiple molecular modalities such as gene expression and microRNA (miR) expression. Our study demonstrated that the mir-508-3p presented as the most powerful determinant of mesenchymal subtype-specific gene expression, tuning the majority of genes differentially expressed in the poor prognosis subtype, including genes associated with the epithelial–mesenchymal transition (EMT) program. Consequent functional experiments illustrate that miR-508-3p inhibition promoted EMT process, in vitro cell migration and invasion, and in vivo cancer metastasis. Overall design: Total RNA was isolated after treatment with control miRNA or miR-508-3p inhibitor in OVTOKO and OVISE cell lines. Two independent experiments were carried out and gene expression profiles were analyzed.
Project description:Unsupervised classification of gene expression profiles has resulted in the identification of biologically and clinically distinct colon cancer subtypes (CCSs). The subtype that associates with poor clinical outcome displays a mesenchymal gene expression profile. No driver mutation has been identified for this category and patients are heterogeneous with regard to commonly used clinical markers. Here we report a regulatory network consisting of the miR-200 family members that tunes the majority of genes differentially expressed in the poor prognosis CCS, including genes involved in the epithelial-mesenchymal transition (EMT) process. Our data indicate that the epigenetic silencing of the miR-200 family by promoter methylation is identifying the mesenchymal CCS and is predictive of disease-free survival in this malignancy. We demonstrate that the molecular features of poor prognosis colon cancer - expression of EMT-associated genes and miR-200 promoter methylation - can already be installed at the premalignant stage, suggesting a highly malignant potential of specific colon cancer precursor lesions. Four colorectal cancer cell lines that display methylated miR-200 loci have been used to overexpress miR-200 family members from both loci separatedly or simultaneously.
Project description:This experiment captures expression over 60,000 well-annotated RefSeq human transcripts over RNA samples from SH-SY5Y neuroblastoma cells transfected with human and non-human primate microRNA mimic variants of miR-299-3p, miR-503-3p, miR-508-3p and miR-541-3p, as well as a RNA duplex negative control (C2 mimic, Dharmacon).
Project description:A variety of human cancers demonstrate alterations in microRNA expression. We hypothesized that regulatory defects in microRNAs play a central early role in organizing the molecular changes involved in ovarian cancer (OvCa). Using both gene arrays and deep sequencing, we comprehensively profiled mRNA and microRNA expression, respectively, in human serous epithelial OvCa cell lines, serous tumors, and short-term primary cultures of normal ovarian surface epithelium (NOSE). We expected that over-expression of a specific microRNA would lead to lower expression of its mRNA targets, and under-expression of a specific microRNA would lead to higher expression of its target genes. Using our expression data in conjunction with established in silico algorithms, we found putative microRNA:mRNA functional pairs. Furthermore, gene expression profiles were taken of serous cultures having functional knockdown or over-expression of specific microRNAs of interest. Over-expression of mir-31 (found under-expressed in serous OvCa) resulted in down-regulation in vitro of a significant number of the in silico predicted mir-31 target genes. Keywords: two group comparison Overall design: We used miRNA mimics to over-express mir-31, originally found under-expressed in OvCa. After 48 hours of mimic treatment, we profiled for gene expression both cells with mir-31 knockup and cells with mimic control (having minimal sequence identity with all human miRNAs).
Project description:Introduction: Ampullary cancer is a relatively rare entity and usually treated by pancreatoduodenectomy followed by adjuvant therapy. The intestinal subtype is associated with markedly improved prognosis after resection. Only few cell lines are available for in vitro studies of ampullary cancer and they have not been collectively characterized. Methods: We characterized available ampullary cancer cell lines by subtype maker expression, epithelial-mesenchymal transition (EMT) features, growth and invasion, drug sensitivity and response to cancer-associated fibroblast conditioned medium (CAF-CM). Results: On the basis of EMT features, subtype marker expression, growth, invasion and drug sensitivity three types of cell lines could be distinguished: mesenchymal-like, pancreatobiliary-like and intestinal-like. In response to CAF-CM, enhanced growth, EMT induction as well as suppression of intestinal differentiation markers were observed, but in a heterogenous pattern. Also proteomic analysis of the CAF response distinguished intestinal-like from other cell lines. Discussion: Most of the available AMPAC cell lines seem to reflect a poorly differentiated pancreatobiliary or mesenchymal-like phenotype, consistent with their origin. We suggest that the best cell line model for intestinal-like AMPAC is the SNU869 cell line, while others seem to reflect aggressive AMPAC subtypes.
Project description:Epithelial ovarian cancer is a very heterogeneous disease and remains the most lethal gynaecological malignancy in the Western world. Rational therapeutic approaches need to account for interpatient and intratumoral heterogeneity in treatment design. Detailed characterization of in vitro models representing the different histological and molecular subtypes is therefore imperative. Strikingly, from ~100 available ovarian cancer cell lines the origin and which subtype they represent is largely unknown. We have extensively and uniformly characterized 39 ovarian cancer cell lines (with mRNA/microRNA expression, exon sequencing, dose response curves for clinically relevant therapeutics) and obtained all available information on the clinical features and tissue of origin of the original ovarian cancer to refine the putative histological subtypes. From 39 ovarian cell lines, 14 were assigned as high-grade serous, four serous-type, one low-grade serous and 20 non-serous type. Three morphological subtypes (21 Epithelial, 7 Round, 12 Spindle) were identified that showed distinct biological and molecular characteristics, including overexpression of cell movement and migration-associated genes for the Spindle subtype. Clinical validation showed a clear association of the spindle-like tumors with metastasis, advanced stage, suboptimal debulking and poor prognosis. In addition, the morphological subtypes associated with the molecular C1-6 subtypes identified by Tothill et al. , Spindle clustered with C1-stromal subtype, Round with C5-mesenchymal and Epithelial with C4 subtype. We provide a uniformly generated data resource for 39 ovarian cancer cell lines, the ovarian cancer cell line panel (OCCP). This should be the basis for selecting models to develop subtype specific treatment approaches, which is very much needed to prolong the survival of ovarian cancer patients. Gene expression was measured for 32 ovarian cancer cell lines using the GeneChip Human Exon 1.0 ST Array (Affymetrix). Morphological subtypes were assigned based on cell morphology, size, growth pattern and proliferation rate during culturing of the cell lines.
Project description:We investigated the effect of miR-1199-5p, miR-200b-3p and miR-429-3p on gene expression profiles during TGFbeta-induced EMT in normal murine mammary gland cells by using the mRNA-sequencing. Our analysis demonstrates that miR-1199-5p and both miR-200 family members share only 6 target genes, indicating that besides regulating Zeb1 expression they exert distinct functions during EMT. Overall design: mRNA profiles of NMuMG cells transiently overexpressing miR-1199-5p, miR-200b-3p or miR-429-3p and treated with TGFbeta for 4 days
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks.
Project description:Biologically and clinically meaningful tumor classification schemes have long been sought. Some malignant epithelial neoplasms, such as those in the thyroid and endometrium, exhibit more than one pattern of differentiation, each associated with distinctive clinical features and treatments. In other tissues, all carcinomas, regardless of morphological type, are treated as though they represent a single disease. To better understand the biological and clinical features seen in the four major histological types of ovarian carcinoma (OvCa), we analyzed gene expression in 113 ovarian epithelial tumors using oligonucleotide microarrays. Global views of the variation in gene expression were obtained using PCA. These analyses show that mucinous and clear cell OvCas can be readily distinguished from serous OvCas based on their gene expression profiles, regardless of tumor stage and grade. In contrast, endometrioid adenocarcinomas show significant overlap with other histological types. Although high-stage/grade tumors are generally separable from low-stage/grade tumors, clear cell OvCa has a molecular signature that distinguishes it from other poor-prognosis OvCas. Indeed, 73 genes, expressed 2- to 29-fold higher in clear cell OvCas compared with each of the other OvCa types, were identified. Collectively, the data indicate that gene expression patterns in ovarian adenocarcinomas reflect both morphological features and biological behavior. Moreover, these studies provide a foundation for the development of new type-specific diagnostic strategies and treatments for ovarian cancer. cho-00156 Assay Type: Gene Expression Provider: Affymetrix Array Designs: Hu6800 Organism: Homo sapiens (ncbitax) Material Types: synthetic_RNA, organism_part, whole_organism, total_RNA Disease States: Ovary cancer
Project description:Genome-wide mRNA expression profiling was performed in AGS, gastric cancer cell line, upon miR-25 silencing. At 48 hours upon anti-miR-25-3p (miRNA inhibitor) and non-targeting control RNA transfection, the whole transcriptome profiling was performed in triplicates. The miR-25 silencing elevates the diffuse gastric cancer features like expression of COL1A2, expression of COL1A2 co-expressed genes, Epithelial to Mesenchymal Transition (EMT) and angiogenesis associated genes. Overall design: AGS cells were transfected with anti-miR-25-3p (miRNA inhibitor) and non-targeting control RNA in triplicates. miRNA inhibitor transfection was performed twice with 24 hrs interval. Total RNA was isolated from the samples after 48 hrs of initial transfection. The RNA samples were processed and hybridized in Human Gene 1.0 ST Array and the differentially expressed probe sets were taken for Gene Set Enrichment Analysis.