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: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.

Project description:An increased serum alkaline phosphatase concentration is known to be associated with a negative prognosis in canine and human osteosarcoma. To expand upon previous studies regarding the biological relevance of increased serum alkaline phosphatase as a negative prognostic factor, xenogeneic heterotopic transplants were performed using six canine primary osteosarcoma cell lines generated from patients with differing serum alkaline phosphatase concentrations (3 normal and 3 increased). Three of the six cell lines were capable of generating tumors and tumor formation was independent of the serum alkaline phosphatase status of the cell line. Microarray analysis identified 379 genes as being differentially-expressed between the tumorigenic and non-tumorigenic cell lines. Frizzled-6 was up-regulated to the greatest extent (7.78 fold) in tumorigenic cell lines compared to non-tumorigenic cell lines. Frizzled-6, a co-receptor for Wnt ligands has been associated with enhanced tumor-initiating cells and poor prognosis for other tumors. The increased expression of frizzled-6 was confirmed by QPCR and Western blot analysis. Additionally, the tumorigenic cell lines also had an increase in the percentage of side population cells compared to non-tumorigenic cell lines (5.89% versus 1.58%, respectively). There were no differences in tumorigenicity, frizzled-6, or percentage of side population cells noted between osteosarcoma cell lines generated from patients of differing serum alkaline phosphatase concentration. However, to our knowledge this is the first study to identified frizzled-6 as a possible marker of osteosarcoma cell populations with enhanced tumorigenicity and side population cells. Future work will focus on defining the role of frizzled-6 in osteosarcoma tumorigenesis and tumor-initiating cells. A total of six canine primary osteosarcoma cell lines were used in this study. Three cell lines were capable of forming tumors when transplanted into mice (tumorigenic) and three cell lines were not capable of forming tumors upon transplant into mice (non-tumorigenic). The gene expression data is from the primary cell lines, not the transplanted cells. There were no reference cell lines or controls used in this study.

Project description:The recent identification of cancer stem cells (CSCs) in multiple human cancers provides a new inroad to understanding tumorigenesis at the cellular level. CSCs are defined by their characteristics of self-renewal, multipotentiality, and tumor initiation upon transplantation. By testing for these defining characteristics, we provide evidence for the existence of CSCs in a transgenic mouse model of glioma, S100Ã-verbB;Trp53. In this glioma model, CSCs are enriched in the side-population (SP) cells. These SP cells have enhanced tumor-initiating capacity, self-renewal, and multipotentiality compared to non-SP cells from the same tumors. Furthermore, gene expression analysis comparing FACS-sorted cancer SP cells to non-SP cancer cells and normal neural SP cells identified 45 candidate genes that are differentially expressed in glioma stem cells. We validated the expression of two genes from this list (S100a4 and S100a6) in primary mouse gliomas and human glioma samples. Analyses of xenografted human GBM (glioblatoma multiforme) cell lines and primary human glioma tissues show that S100A4 and S100A6 are expressed in a small subset of cancer cells and that their abundance is positively correlated to tumor grade. In conclusion, this study shows that CSCs exist in a mouse glioma model, suggesting that this model can be used to study the molecular and cellular characteristics of CSCs in vivo and to further test the cancer stem cell hypothesis. Experiment Overall Design: This study features two factors, injected cell origin (either tumorsphere or neurosphere) and FACS cell population (either side population or non-side population cells). There were two different tumorspheres, labeled 3447 and 4346 that were isolated from brain tumors in S100beta-verbB;p53-/- or S100beta-verbB;p53+/- mice. The tumorspheres were injected separately into the brains of NOD.Cg-Prkdc<scid>Il2rg<tm1Wjl>/SzJ mice to generate biological triplicates of each primary tumor. Tumorspheres were isolated and cultured before FACS sorting to obtain side population and non-side population cells. As a control, untransformed neurospheres from three independent S100beta-verbB;p53-/- or S100beta-verbB;p53+/- mice were isolated, cultured, and FACS sorted to obtain side population and non-side population cells. Side population and non-side population cells cultured from three mice injected with the 3447 cultured tumorspheres were assayed for gene expression (six samples). Side-population stem cells cultured from three mice injected with the 4346 cultured tumorspheres were assayed for gene expression (three samples). Side-population and non-side population cells cultured from three mice injected with the neurospheres were assayed for gene expression (six samples).

Dataset Information

Homo sapiens

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets