Development and Characterisation of Acquired Radioresistant Breast Cancer Cell Lines.
ABSTRACT: Background: Radiotherapy plays an important role in the multimodal treatment of breast cancer. The response of a breast tumour to radiation depends not only on its innate radiosensitivity but also on tumour repopulation by cells that have developed radioresistance. Development of effective cancer treatments will require further molecular dissection of the processes that contribute to resistance. Methods: Radioresistant cell lines were established by exposing MDA-MB-231, MCF-7 and ZR-751 parental cells to increasing weekly doses of radiation. The development of radioresistance was evaluated through proliferation and colony formation assays. Phenotypic characterisation included migration and invasion assays and immunohistochemistry. Intrinsic differences and changes in response to radiation between parental and radioresistant cells were investigated by whole-transcriptome gene expression analysis. Gene enrichment and pathway-focused analyses identified signalling networks differentially activated in radioresistant cells, which were confirmed by western blotting. Results: Proliferation and colony formation assays confirmed radioresistance. Radioresistant cells exhibited enhanced migration and invasion, with evidence of epithelial-to-mesenchymal-transition, and limited activation of DNA damage and apoptotic pathways in response to 2 Gy ionising radiation. Significantly, acquisition of radioresistance in MCF-7 and ZR-751 cell lines resulted in a loss of expression of both ERα and PgR and an increase in EGFR expression; based on gene analysis they changed subtype classification from their parental luminal A to HER2-overexpressing (MCF-7 RR) and normal-like (ZR-751 RR) subtypes, indicating the extent of phenotypic changes and cellular plasticity involved in this process. Whole-transcriptome gene expression analysis identified down-regulation of ER signalling genes and up-regulation of genes associated with PI3K, MAPK and WNT pathway activity in radioresistant cell lines derived from ER+ cells; this was confirmed by western blot, which showed increased p-AKT and p-ERK expression following radiation. Conclusions: This is the first study to date that extensively describes the development and characterisation of three novel radioresistant breast cancer cell lines through both genetic and phenotypic analysis. More changes were identified between parental cells and their radioresistant derivatives in the ER+ (MCF-7 and ZR-751) compared with the ER- cell line (MDA-MB-231) model; however, multiple and likely interrelated mechanisms were identified that may contribute to the development of acquired resistance to radiotherapy. Overall design: Whole-genome transcriptomic analysis of 3 breast cancer cell lines (MCF-7, ZR-751 and MDA-MB-231) and 3 radio-resistant models derived from these (MCF-7 RR, ZR-751 RR, MDA-MB-231 RR), using Lexogen QuantSeq technolog). Please note that the 0G and 2G labels (in the sample title) refer to the treatment received: 0 Gray (untreated) or 2 Gray (radiation treatment).
Project description:RNA-Seq profiling of MCF-7 and MDA-MB-231. We profiled RNA expression in the estrogen-receptor-positive (ER+) MCF-7 and the triple-negative MDA-MB-231 breast cancer cells. The objective was to find genes differentially expressed between these cell lines as potential drivers of invasiveness of the triple-negative MDA-MB-231. We further utilized the identified differential genes to validate expression-responsive module of non-canonical Wnt signaling pathway. Overall design: 2 biological replicates of MCF-7 and 3 biological replicates of MDA-MB-231
Project description:The long-term goal of our study is to understand the genetic and epigenetic mechanisms of breast cancer metastasis in human and to discover new possible genetic markers for use in clinical practice. We have used microarray technology (Human OneArray microarray, phylanxbiotech.com) to compare gene expression profiles of non-invasive MCF-7 and invasive MDA-MB-231 cells exposed to dioscin (DS), a steroidal saponin isolated from the roots of wild yam, (Dioscorea villosa). Initially the differential expression of genes (DEG) was identified that followed pathway enrichment analysis (PEA). Of the genes queried on OneArray, we identified 4641 DEG changed between MCF-7 and MDA-MB-231 cells (vehicle-treated) with cut-off log2 |fold change|≧ 1. Among these genes, 2439 genes are upregulated and 2002 genes are downregulated. DS exposure (2.30 M, 72 h) to these cells identified 801 (MCF-7) and 96 (MDA-MB-231) DEG that showed significant difference compared to untreated cells (p<0.05). Within these gene sets, DS is able to upregulate 395 genes and downregulate 406 genes in MCF-7 and upregulate 36 and downregulate 60 genes in MDA-MB-231 cells. Further comparison of DEG between MCF-7 and MDA-MB-231 cells exposed to DS identified 3626 DEG of which 1700 were upregulated and 1926 genes were down-regulated. From PEA, 12 canonical pathways were significantly altered between these two cell lines (MCF-7 and MDA-MB-231). However, no alteration in any of these pathways was noticed in MCF-7 cell, while in MDA-MB-231 cells only MAPK pathway showed significant alteration. When PEA comparison was made on DS exposed cells, it was observed that only 2 pathways were significantly affected. Further, to identify shared DEG, which are targeted by DS and overlapped in both MCF-7 and MDA-MB-231 cells, we performed intersection analysis (Venn diagram). We found that only 7 DEG are overlapped of which six are reported in the database. This study highlights the diverse gene networks and pathways through which DS exhibits its effect on breast cancer cells. Two condition experiment. Human breast cancer Cell line MCF-7 groups: Vehicle control and dioscin treated; Human breast cancer cell line MDA-MB-231 cell group; vehicle control and dioscin-treated. Biological replicates: MCF-7 control compared to MCF-7 dioscin treated; MDA-MB-231 control compated to MDA-MB-231 dioscin-treated; MCF-7 control compared to MDA-MB-231 control; MCF-7 dioscin treated compared to MDA-MB-231 dioscin-treated. duplicate array
Project description:We previously identified small molecules that fit into a BRCA1-binding pocket within estrogen receptor-alpha (ER), mimic the ability of BRCA1 to inhibit ER activity (“BRCA1-mimetics”), and overcome antiestrogen resistance. One such compound, the hydrochloride salt of NSC35446 (“NSC35446.HCl”), also inhibited growth of antiestrogen-resistant LCC9 tumor xenografts. The purpose of this study was to investigate the down-stream effects of NSC35446.HCl and its mechanism of action. Methods: Here, we studied antiestrogen-resistant (LCC9, T47DCO, MCF-7/RR, LY2), ER-negative (MDA-MB-231, HCC1806, MDA-MB-468), and antiestrogen-sensitive (MCF-7) cell lines. Techniques utilized include RNA-seq, qRT-PCR, cell growth analysis, cell-cycle analysis, Western blotting, luciferase reporter assays, TUNEL assays, in-silico analysis of the IKKB gene, and ChIP assays. Results: NSC35446.HCl inhibited proliferation and induced apoptosis in antiestrogen resistant LCC9, T47DCO, MCF-7/RR, and LY2 cells but not in ER-negative breast cancer cell lines. IKKB (IKKβ, IKBKB), an upstream activator of NF-B, was identified as a BRCA1-mimetic-regulated gene, based on an RNA-seq analysis; and NSC35446.HCl inhibited IKKB mRNA and protein expression in LCC9 cells. NSC35446.HCl also inhibited NF-B activity and expression of NF-B target genes. In-silico analysis of the IKKB promoter identified nine estrogen response element (ERE) half-sites and one ERE-like full-site. ChIP assays revealed that ER was recruited to the ERE-like full-site and five of the nine half-sites and that ER recruitment was inhibited by NSC35446.HCl in LCC9 and T47DCO cells. Conclusions: These studies identify functional EREs in the IKKB promoter and identify IKKB as an NSC35446.HCl-regulated gene; and they suggest that NF-B and IKKB, which were previously linked to antiestrogen resistance, are targets for NSC35446.HCl in reversing antiestrogen resistance. Overall design: Examination of mRNA profiles of BRCA1 mimetic treated LCC9 cells: 4 samples Total: 2 Vehicle(DMSO) Control and 2 BRCA1 mimetic (A7) treated LCC9 cells
Project description:This study aimed to further our understanding of the role that CXCR6 plays in breast cancer progression. Microarrays were searched for some genes that had correlated expression with CXCR6 mRNA. According to fold-change screening between restoring expression of CXCR6 and its respective control cells in MDA-MB-231 and MCF-7 cells, both up-regulated and down-regulated genes were shown. The restoring of CXCR6 expression in MDA-MB-231 and MCF-7 cells were respectively noted as MDA-MB-231-CXCR6 and MCF-7-CXCR6 cells and the respective controls were noted as MDA-MB-231-GFP and MCF-7-GFP cells.
Project description:In order to identify novel molecular targets associated with TNBC progression, we initially performed transcriptome analysis using RNA sequencing in breast cancer cell lines, classified as either the luminal subtype (MCF-7, T47D, ZR-75B) or basal-like subtype (MDA-MB-231, MDA-MB-435, Hs578T). Overall design: Total RNAs of each cell were isolated using the TRIzol reagent for RNA sequencing following manufacturer’s instructions. The total RNAs were treated with DNase I, purified with miRNeasy Mini Kit and subsequently quality checked using an Agilent 2100 Bioanalyzer. An Illumina platform was used to analyze transcriptomes with 90 bp paired-end library. Samples were paired-end sequenced with the Illumina HiSeq 2000 using HiSeq Sequencing kits.
Project description:Mesenchymal stromal cells were cultured in 3D PEG hydrogels for 7 days in the presence of serum-free media or conditioned media from a panel of breast cancer cells (MCF-7, MDA-MB-231, MDA-MB-231 lung-tropic, MDA-MB-231 brain-tropic, MDA-MB-231 bone-tropic). In all cases, the secretomes were collected after cancer cells were in serum-free media for 24h.
Project description:This Series reports results of miRNA profiling of estrogen-receptor-positive (MCF7) and estrogen-receptor-negative (MDA-MB-231) cells. Retinoic Acid (RA) induces mir-21 in MCF-7 but not in MDA-MB-231 cells. MCF-7 and MDA-MB-231 cells were treated (or not) with retinoic acid (RA) and grown for either 6 hours or 48 hours. miRNA profiling: Factorial design 2x2x2 'cube'; main factors: RA, cells, time; interactions: RA.cells, RA.time, cells.time, RA.cells.time.
Project description:We investigated the differentially expressed genes between MCF-7 and MCF-7-14, and estimated the similarities of expression profiles between MCF-7-14 and MDA-MB-231. We identified genes differentially expressed between non-invasive/non-metastatic and invasive/metastatic breast cancer cells. Experiment Overall Design: We performed microarray analysis as following design: MCF-7 versus MCF-7-14 versus MDA-MB-231 cells.
Project description:This Series reports results of miRNA profiling of estrogen-receptor-positive (MCF7) and estrogen-receptor-negative (MDA-MB-231) cells. Retinoic Acid (RA) induces mir-21 in MCF-7 but not in MDA-MB-231 cells. MCF-7 and MDA-MB-231 cells were treated (or not) with retinoic acid (RA) and grown for either 6 hours or 48 hours. Overall design: miRNA profiling: Factorial design 2x2x2 'cube'; main factors: RA, cells, time; interactions: RA.cells, RA.time, cells.time, RA.cells.time.
Project description:We investigated the differentially expressed genes between MCF-7 and MCF-7-14, and estimated the similarities of expression profiles between MCF-7-14 and MDA-MB-231. We identified genes differentially expressed between non-invasive/non-metastatic and invasive/metastatic breast cancer cells. Overall design: We performed microarray analysis as following design: MCF-7 versus MCF-7-14 versus MDA-MB-231 cells.