Dataset Information

Epigenetic regulation of miR-21 in colorectal cancer: ITGB4 as a novel miR-21 target and a three-gene network (miR-21-ITG?4-PDCD4) as predictor of metastatic tumor potential.

ABSTRACT: Previous studies have uncovered several transcription factors that determine biological alterations in tumor cells to execute the invasion-metastasis cascade, including the epithelial-mesenchymal transition (EMT). We sought to investigate the role of miR-21 in colorectal cancer regulation. For this purpose, miR-21 expression was quantified in a panel of colorectal cancer cell lines and clinical specimens. High expression was found in cell lines with EMT properties and in the vast majority of human tumor specimens. We demonstrate in a cell-specific manner the occupancy of MIR-21 gene promoter by AP-1 and ETS1 transcription factors and, for the first time, the pattern of histone posttranslational modifications necessary for miR-21 overexpression. We also show that Integrin-?4 (ITG?4), exclusively expressed in polarized epithelial cells, is a novel miR-21 target gene and plays a role in the regulation of EMT, since it is remarkably de-repressed after transient miR-21 silencing and downregulated after miR-21 overexpression. miR-21-dependent change of ITG?4 expression significantly affects cell migration properties of colon cancer cells. Finally, in a subgroup of tumor specimens, ROC curve analysis performed on quantitative PCR data sets for miR-21, ITG?4, and PDCD4 shows that the combination of high miR-21 with low ITG?4 and PDCD4 expression is able to predict presence of metastasis. In conclusion, miR-21 is a key player in oncogenic EMT, its overexpression is controlled by the cooperation of genetic and epigenetic alterations, and its levels, along with ITG?4 and PDCD4 expression, could be exploited as a prognostic tool for CRC metastasis.

SUBMITTER: Ferraro A

PROVIDER: S-EPMC3928175 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

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Publications

Epigenetic regulation of miR-21 in colorectal cancer: ITGB4 as a novel miR-21 target and a three-gene network (miR-21-ITGΒ4-PDCD4) as predictor of metastatic tumor potential.

Ferraro Angelo A Kontos Christos K CK Boni Themis T Bantounas Ioannis I Siakouli Dimitra D Kosmidou Vivian V Vlassi Margarita M Spyridakis Yannis Y Tsipras Iraklis I Zografos George G Pintzas Alexander A

Epigenetics 20131022 1

Previous studies have uncovered several transcription factors that determine biological alterations in tumor cells to execute the invasion-metastasis cascade, including the epithelial-mesenchymal transition (EMT). We sought to investigate the role of miR-21 in colorectal cancer regulation. For this purpose, miR-21 expression was quantified in a panel of colorectal cancer cell lines and clinical specimens. High expression was found in cell lines with EMT properties and in the vast majority of hum ...[more]

PMID: 24149370

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Project description:Cardiac progenitor cells derived from adult heart have emerged as one of the most promising stem cell types for cardiac protection and repair. Exosomes are known to mediate cell-cell communication by transporting cell-derived proteins and nucleic acids, including various microRNAs (miRNAs). Here we investigated the cardiac progenitor cell (CPC)-derived exosomal miRNAs on protecting myocardium under oxidative stress. Sca1(+)CPCs-derived exosomes were purified from conditional medium, and identified by nanoparticle trafficking analysis (NTA), transmission electron microscopy and western blotting using CD63, CD9 and Alix as markers. Exosomes production was measured by NTA, the result showed that oxidative stress-induced CPCs secrete more exosomes compared with normal condition. Although six apoptosis-related miRNAs could be detected in two different treatment-derived exosomes, only miR-21 was significantly upregulated in oxidative stress-induced exosomes compared with normal exosomes. The same oxidative stress could cause low miR-21 and high cleaved caspase-3 expression in H9C2 cardiac cells. But the cleaved caspase-3 was significantly decreased when miR-21 was overexpressed by transfecting miR-21 mimic. Furthermore, miR-21 mimic or inhibitor transfection and luciferase activity assay confirmed that programmed cell death 4 (PDCD4) was a target gene of miR-21, and miR-21/PDCD4 axis has an important role in anti-apoptotic effect of H9C2 cell. Western blotting and Annexin V/PI results demonstrated that exosomes pre-treated H9C2 exhibited increased miR-21 whereas decreased PDCD4, and had more resistant potential to the apoptosis induced by the oxidative stress, compared with non-treated cells. These findings revealed that CPC-derived exosomal miR-21 had an inhibiting role in the apoptosis pathway through downregulating PDCD4. Restored miR-21/PDCD4 pathway using CPC-derived exosomes could protect myocardial cells against oxidative stress-related apoptosis. Therefore, exosomes could be used as a new therapeutic vehicle for ischemic cardiac disease.

Dataset Information

Epigenetic regulation of miR-21 in colorectal cancer: ITGB4 as a novel miR-21 target and a three-gene network (miR-21-ITG?4-PDCD4) as predictor of metastatic tumor potential.

Publications

Epigenetic regulation of miR-21 in colorectal cancer: ITGB4 as a novel miR-21 target and a three-gene network (miR-21-ITGΒ4-PDCD4) as predictor of metastatic tumor potential.

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