Development of gene expression signatures for breast cancer stem cells (SP cells)
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ABSTRACT: To further compare gene expression profile between breast cancer stem cells (SP cells) and non-SP cells, we have employed illumina GEX microarray as a discovery platform to identify gene differential expression between SP with non-SP cells. SP analysis and sorting were done using a FACSVantage SE.The breast cancer cells were sorted into SP and non-SP cells.Total RNA was isolated from the FACS-sorted SP or non-SP cells, and gene expression signiture was detected by microarray.
Project description:We are currently studying the mechanisms that confer tumour initiating potential upon SP, and as part of this work, we undertook gene profiling studies comparing expression between SP and non-SP cells, initially focusing on the most common soft tissue sarcoma, malignant fibrous histiocytoma (or MFH) Sarcomas contain a subpopulation of cells which exclude Hoechst dye (SP cells) and are enriched for tumor initiating potential. The persistence of SP cells could be responsible for relapse or a failed response to therapy. Expression profiles were compared between the SP and non-SP cells from malignant fibrous histiocytoma (MFH) tumors using microarray. The Hedgehog and Notch pathways were activated in SP cells. Blocking these pathways in MFH xenografts established in NOD-SCID mice depleted the abundance of SP cells and reduced tumor growth. Intriguingly, treatment also substantially inhibited the potential for successful secondary transplantation. The data provides support that SP cells act as tumor initiating cells in sarcomas and suggests targeting the SP as an enticing approach for sarcoma therapy. In this study, we studied six MFH tumours, and identified a number of signaling pathways that were consistently activated in the SP population compared to the non-SP population.
Project description:Intratumoral heterogeneity is a major barrier against effective cancer therapy. Human malignant mesothelioma (HMM) that is closely associated with asbestos exposure is extremely heterogeneous in morphology and molecular phenotype. Contrast to genetic mutations, the role of epigenetic modifications in the generation and maintenance of heterogeneous populations in cancers remains largely undetermined. The present study was performed to investigate underlying molecular mechanisms for the emergence of intratumoral heterogeneity by identifying the global microRNA expression profile of distinct subpopulations of MS1 cell line, a HMM cell line. More aggressive cancer cells could be enriched by side population (SP) assay in HMM [20]. The sorted SP and NSP subpopulations were subjected to the microarray analysis of miRNA expression to investigate differentially altered miRNA genes defining tumor heterogeneity in HMM. Total RNAs were isolated from the sorted subpopulations of HMM cells, SP and non-SP fractions. The expression profile of miRNAs was evaluated using Affymetrix GeneChip miRNA Arrays. After data extraction and normalization, the microRNAs defining the cell subpopulations were determined using bioinformatics softwares. A total of 95 miRNAs including 42 up-regulated and 53 down-regulated were identified based on the criteria of 2 fold difference and a p-value < 0.05. Functional ontology of the dysregulated miRNAs revealed that a large number of target genes were categorized into the regulation of various cellular processes, including cell proliferation, programmed cell death, cell migration, cellular response to stress, and stem cell maintenance. The data show that microRNAs are significantly involved in the generation and maintenance of intratumoral heterogeneity and their regulation could be an effective strategy to eradicate a more aggressive cancer cell subpopulation. This is the first to report the profile of miRNA expression in CSCs in HMM by using side population assay assisted with flow cytometry. It will be valuable to understand the regulatory function of HMM CSC miRNAs in generation and maintenance of intratumoral heterogeneity. Total RNAs were isolated from the sorted subpopulations of HMM cells, SP and non-SP fractions. (no replicates)
Project description:Immature cell populations, including stem cells and progenitor cells, can be found in M-bM-^@M-^\side-population (SP)M-bM-^@M-^] cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP cells remained to be reported. We used microarrays to detail the global program of gene expression underlying cell differentiation and identified up-regulated genes of SP HTR-8/SVneo SP cells or NSP cells were isolated using a FACS Vantage fluorescence-activated cell sorter (BD Bioscience, San Jose, California) using dual wavelength analysis (blue, 424 - 444nm; red 675 nm) after excitation with 350 nm UV light. PI-positive dead cells were excluded from the analysis. Sorted SP and NSP cells' RNA had been analyzed by microarray analysis.
Project description:To further compare gene expression profile between breast cancer stem cells (SP cells) and non-SP cells, we have employed illumina GEX microarray as a discovery platform to identify gene differential expression between SP with non-SP cells.
Project description:To identify the potential ovarian cancer stem cell gene expression profile from isolated side population of fresh ascites obtained from women with high-grade advanced stage papillary serous ovarian adenocarcinoma Microarrays were used to interrogate the differentially expressed genes between side population (SP) and main population (MP) isolated from fresh ascites obtained from women with high-grade advanced stage papillary serous ovarian adenocarcinoma, and the results were analyzed by paired T-test using BRB-ArrayTools Gene expression profiling was completed for 10 SP and MP pairs using the Affymetrix human U133 Plus 2.0 Arrays
Project description:Side population (SP) cells are enriched with genes involved in stem cell activity and/or lineage specifications. Stem cell marker genes are upregulated after partial thyroidectomy. Four-condition experiment: control side population (CSP) vs. control main population (CMP) vs. thyroidectomized side population (TSP) vs. thyroidectomized main population (TMP). Biological replicates: 6 CSP, 3 CMP, 6 TSP, and 3 TMP samples.
Project description:Analysis of Hoechst 33342 dye-effluxing side population cells (SP cells defined as glioma stem cells, GSCs) and dye-retaining main population cells (MP cells defined as non-GSCs) that were FACS-sorted from the C6 glioma cell line stably expressing EGFP (C6-eGFP). ECM-related genes, such as Col4a1 and Col4a2, and the iron carrier gene Tf are upregulated in MP cells. Results provide the insight into molecular basis underlying the maintenance of GSCs by non-GSCs. Gene expression profiles were compared between SP and MP cells just after FACS-sorting from the whole C6-eGFP cells based on their Hoechst-effluxing abilities.
Project description:In rainbow trout, type A spermatogonia can be split into SP cells and non-SP cells by the ability to exclude Hoechst 33342 dye (H33342). The H33342 fluorescence of SP cells are lower than that of non-SP cells, after H33342 staining. To investigate whether SP cells were transcriptomically distinct from non-SP cells, we compared the transcriptome of these cells. We used fluorescence-activated cell sorting (FACS) to isolate SP cells and non-SP cells from the type A spermatogonia in rainbow trout. To compensate unavailability of genetically uniform rainbow trout in independent sampling, SP cells and non-SP cells were collected at 3 times from 3 different parental fish groups. This experimental design allowed us to estimate effects specific to each parental fish genotype on mRNA expression in SP cells by a statistical modeling and to exclude the effects in subsequent analysis.
Project description:Purpose: To explore the side population (SP) in pancreatic ductal adenocarcinoma (PDAC) for its gene expression profile and its association to cancer stem cells (CSC) and to evaluate the value of genes from its gene signature on patient survival. Experimental design: Side and main population (MP) cells were isolated from 11 human PDAC resection specimens using fluorescence-activated cell sorting (FACS) after Hoechst incubation. Total RNA was extracted for whole-genome analysis. A gene signature for the purified SP (pSP; depleted from immune/endothelial CD45+/CD31+ cells) was developed and validated with the nCounter system on expression data of 78 primary PDAC using Cox regression analyses for disease-free and overall survival. Results: An SP was identified in all PDAC samples. Whole-genome expression profiling of pSP revealed upregulation of genes related to therapy-resistance and of CSC-associated genes and pathways. A pSP signature of 32 up- or downregulated genes was capable of discriminating SP from MP in an independent set of 10 PDAC samples, and some contributing genes had a prognostic value in a separate series of 78 patients who underwent surgery for PDAC. Conclusion: Pancreatic cancer contains an SP with chemo-resistant and CSC-associated molecular characteristics. Genes from a newly defined pSP gene signature are related to survival of patients who undergo surgical resection for pancreatic cancer, and might therefore represent potential therapeutic targets. Microarray analysis was performed on SP and MP samples from 11 different human PDAC samples.
Project description:Malignant pleural mesothelioma (MPM), which is associated with occupational asbestos exposure, is a deadly disease with no effective treatments due mainly to its high resistance to anti-cancer drugs. The molecular mechanisms responsible for its chemotherapeutic resistance are complicated and undefined. However, the presence of side population cells (SP cells) in tumors is a well-accepted explanation for their anti-cancer drug resistance. To identify SP cell-specific gene expression signature, microarray technique has been employed. Our data show differential gene expression profiles between SP and non-SP cells of H2714 mesothelioma cells. SP cells over-expressed genes associated with cancer stem cell (CSC) and drug resistance: DUSP6, SPRY2 and IL6, as well as multi-pathways, including the cancer stem cell-associated pathways Notch and c-Kit. Therefore, we believe that targeting CSC-specific genes and pathways in SP cells may hold the key to the discovery of effective treatments for reversing chemotherapeutic resistance to MPM treatment. 4 samples