Limited knowledge of the downstream targets of hnRNP A2/B1 has, however, precluded a clear understanding of their roles in cancer cell growth. To define the pathways in which this protein acts we have now carried out microarray experiments with total RNA from Colo16 epithelial cells transfected with an shRNA that markedly suppresses hnRNP A2/B1 expression. The microarray data identified 123 genes, among 22283 human gene probe sets, with altered expression levels in hnRNP A2/B1-depleted cells. Ontological analysis showed that many of these downstream targets are involved in regulation of the cell cycle and cell proliferation and that this group of proteins is significantly over-represented amongst the affected proteins. The changes detected in the microarray experiments were confirmed by real-time PCR for a subset of proliferation-related genes. Immunoprecipitation-RT-PCR demonstrated that hnRNP A2/B1 formed complexes with the transcripts of many of the verified downstream genes, suggesting that hnRNP A2/B1 contributes to the regulation of these genes.
Downstream targets of heterogeneous nuclear ribonucleoprotein A2 mediate cell proliferation.
Sex, Age, Specimen part
View SamplesThe epidermal growth factor receptor (EGFR) is frequently overexpressed in cancer and is an important therapeutic target. Aberrant expression and function of microRNAs has been associated with tumorigenesis. Bioinformatic predictions suggest that the human EGFR mRNA 3-untranslated region contains three microRNA-7 (miR-7) target sites, which are not conserved across mammals. We found that miR-7 down-regulates EGFR mRNA and protein expression in cancer cell lines (lung, breast, and glioblastoma) via two of the three sites, inducing cell cycle arrest and cell death. Because miR-7 was shown to decrease EGFR mRNA expression, we used microarray analysis to identify additional mRNA targets of miR-7. These included Raf1 and multiple other genes involved in EGFR signaling and tumorigenesis. Furthermore, miR-7 attenuated activation of protein kinase B (Akt) and extracellular signal-regulated kinase 1/2 (ERK1/2), two critical effectors of EGFR signaling, in different cancer cell lines. These data establish an important role for miR-7 in controlling mRNA expression and indicate that miR-7 has the ability to coordinately regulate EGFR signaling in multiple human cancer cell types.
Regulation of epidermal growth factor receptor signaling in human cancer cells by microRNA-7.
No sample metadata fields
View SamplesPrdx2 is the thioredoxin-dependent peroxidase that reduces H2O2 using reducing power NADPH in the presence of thioredoxin and thioredoxin reductase. Prdx2 plays an important role in growth. factor signaling in mammlian cells. Therefore, we examined the gene expression in colon adenocarcinoma cell line HT29 after Prdx2 depletion. Prdx2 depletion resulted in a significant alteration on gene expression, including protein synthesis, metabolisms, and cell cycle. Overall design: Control-siRNA-transfected versus PRDX2-siRNA-transfected HT29 and SW480 cells
Interaction of tankyrase and peroxiredoxin II is indispensable for the survival of colorectal cancer cells.
Cell line, Subject
View SamplesElevated expression and activity of the epidermal growth factor receptor (EGFR)/protein kinase B (Akt) signaling pathway is associated with development, progression and treatment resistance of head and neck cancer (HNC). Several studies have demonstrated that microRNA-7 (miR-7) regulates EGFR expression and Akt activity in a range of cancer cell types via its specific interaction with the EGFR mRNA 3 untranslated region (3-UTR). In the present study, we found that miR-7 regulated EGFR expression and Akt activity in HNC cell lines, and that this was associated with reduced growth in vitro and in vivo of cells (HN5) that were sensitive to the EGFR tyrosine kinase inhibitor (TKI) erlotinib (Tarceva). miR-7 acted synergistically with erlotinib to inhibit growth of erlotinib-resistant FaDu cells, an effect associated with increased inhibition of Akt activity. Microarray analysis of HN5 and FaDu cell lines transfected with miR-7 identified a common set of downregulated miR-7 target genes, providing insight into the tumor suppressor function of miR-7. Furthermore, we identified several target miR-7 mRNAs with a putative role in the sensitization of FaDu cells to erlotinib. Together, these data support the coordinate regulation of Akt signaling by miR-7 in HNC cells and suggest the therapeutic potential of miR-7 alone or in combination with EGFR TKIs in this disease.
Regulation of epidermal growth factor receptor signaling and erlotinib sensitivity in head and neck cancer cells by miR-7.
Specimen part, Cell line
View SamplesAlthough cancer stem cells (CSCs) are thought to be responsible for tumor recurrence and resistance to chemotherapy, CSC-related research and drug development have been hampered by the limited supply of patient-derived diverse CSCs. Here, we developed a functional polymer thin film (PTF) platform that promotes conversion of human cancer cell lines to highly tumorigenic spheroids without the use of biochemical or genetic manipulations. Culturing various human cancer cells on the specific PTF, poly(2,4,6,8-tetravinyl-2,4,6,8-tetramethyl cyclotetrasiloxane) (pV4D4), gave rise to numerous multicellular spheroids within 24 hours, with high efficiency and reproducibility. Cancer cells in the resulting spheroids showed an enormous increase in the expression of CSC-associated genes and acquired dramatically increased drug resistance compared with monolayer-cultured controls. These spheroids also showed greatly enhanced xenograft tumor-forming ability and metastasis capacity in nude mice. By enabling the generation of tumorigenic spheroids as a patient-derived CSC substitute, the surface platform described here will likely contribute to CSC-related basic research and drug development. Overall design: mRNA profiles of 8 day-SKOV3-ssiCSC spheroids and 2D-cultured SKOV3 control were generated by deep sequencing, in duplicate, using Hiseq-2500.
Polymer Thin Film-Induced Tumor Spheroids Acquire Cancer Stem Cell-like Properties.
Specimen part, Subject
View Samplesnc886 is a 101 nucleotides long non-coding RNA that is also known as a precursor microRNA or a vault RNA. nc886 has been suggested to be a tumor suppressor, mainly inferred by its expression pattern as well as its genomic location at human chromosome 5q31, a locus for a tumor suppressor gene(s).
Epigenetic silencing of the non-coding RNA nc886 provokes oncogenes during human esophageal tumorigenesis.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An integrated systems biology approach identifies positive cofactor 4 as a factor that increases reprogramming efficiency.
Sex, Specimen part
View SamplesMultipotent spermatogonial stem cells (mSSCs) derived from SSCs are a potential new source of individualized pluripotent cells in regenerate medicine such as ESCs. We hypothesized that the culture-induced reprogramming of SSCs was mediated by a mechanism different from that of iPS, and was due to up-regulation of specific pluripotency-related genes during cultivation. Through a comparative analysis of expression profile data, we try to find cell reprogramming candidate factors from mouse spermatogonial stem cells. We used microarrays to analyze the gene expression profiles of culture-induced reprogramming converting unipotent spermatogonial stem cells to pluripotent spermatogonial stem cells.
An integrated systems biology approach identifies positive cofactor 4 as a factor that increases reprogramming efficiency.
Sex, Specimen part
View SamplesSpermatogonial stem cells (SSCs) can spontaneously dedifferentiate into embryonic stem cell (ESC)-like cells, which are designated as multipotent SSCs (mSSCs), without ectopic expression of reprogramming factors. SSCs express key OSKM reprogramming factors at some levels, and do not require ectopic expression of any gene for the acquisition of pluripotency during reprogramming to mSSCs. Therefore, we reasoned that additional factors are required to regulate SSC reprogramming. In this study, we first compared the expression of reprogramming signature genes among somatic cells, iPSC, SSCs, mSSCs, and partially reprogramed cells, and found that they appear to have similar pluripotency states, whereas their transcriptional program differs. We developed a systems biology approach to prioritise genes for pluripotency regulatory factors by integrating transcriptome and interactome data on the genome-wide functional network. Then, we performed a series of systematic gene prioritisation steps and identified 53 candidates, which included some known reprogramming factors. We experimentally validated one particular candidate, Positive cofactor 4 (Pc4), which was expressed in PSCs and yielded a positive RNA interference (RNAi) response in an Oct4 reporter assay. We demonstrated that Pc4 enhanced the efficiency of OSKM-mediated reprogramming by promoting the transcriptional activity of key pluripotency factors, and by regulating the expression of many protein- and miRNA-encoding genes involved in reprogramming and somatic cell-specific genes. Overall design: Pc4-overexpressing mESC lines were established by Venus (YFP)-expressing lentiviral transfection. The mESCs were split at a density of 2 ´ 104 cells onto fresh MEF feeder cells seeded into a 6 well dish (containing mESC growth medium) with virus particles, and 25 µg/ml polybrene (Sigma Aldrich) was added. After 24 h, the medium was replaced with fresh growth medium. After 4 days later, mESC colonies expressing YFP were picked and replated. Three different Pc4-overexpressing mESC lines were established.
An integrated systems biology approach identifies positive cofactor 4 as a factor that increases reprogramming efficiency.
Specimen part, Cell line, Subject
View SamplesProtein arginine methyltransferase-6 (PRMT6) regulates steroid-dependent transcription and alternative splicing, and is implicated in endocrine system development and function, cell death, cell cycle, gene expression and cancer. Despite its role in these processes, little is known about its function and cellular targets in breast cancer. To identify novel gene targets regulated by PRMT6 in breast cancer cells, we used a combination of small interfering RNA (siRNA) and exon-specific microarray profiling in vitro, coupled to in vivo validation in normal breast and primary human breast tumours. This approach, which allows the examination of genome-wide changes in individual exon usage and total transcript levels, demonstrated PRMT6 knockdown significantly affected: (i) the transcription of 159 genes, and (ii) alternate splicing of 449 genes. Importantly, the levels of PRMT6 itself were significantly decreased in breast cancer, relative to normal breast tissue. The PRMT6 dependent transcriptional and alternative splicing targets identified in vitro, were validated in human breast tumours. Notably, expression of PRMT6 and the corresponding gene signature, correlated with decreased probability of relapse-free or distant metastasis free survival in ER+ breast cancer. These results suggest that dysregulation of PRMT6 dependent transcription and alternative splicing may be involved in breast cancer pathophysiology and the molecular consequences identifying a unique and informative biomarker profile.
Protein arginine methyltransferase 6-dependent gene expression and splicing: association with breast cancer outcomes.
Cell line, Treatment
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