微小RNA-377通过抑制DNA甲基转移酶1并使肿瘤抑制基因去甲基化来逆转胰腺细胞的癌性表型。

MiR-377 reverses cancerous phenotypes of pancreatic cells via suppressing DNMT1 and demethylating tumor suppressor genes.

作者信息

Azizi Masoumeh, Fard-Esfahani Pezhman, Mahmoodzadeh Habibollah, Fazeli Mohammad Sadegh, Azadmanesh Kayhan, Zeinali Sirous, Teimoori-Toolabi Ladan

机构信息

Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.

Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran.

出版信息

Epigenomics. 2017 Aug;9(8):1059-1075. doi: 10.2217/epi-2016-0175. Epub 2017 Jul 31.

DOI:10.2217/epi-2016-0175

PMID:28758420

Abstract

AIM

The aim was to investigate the effect of miR-377 on DNMT1 expression and cancer phenotype in pancreatic cancer cells.

MATERIALS & METHODS: Real-time PCR, luciferase assay, MTT and Annexin-PI staining were used.

RESULTS

Decreased miR-377 and increased DNMT1 (verified as a target for mir-377) levels in pancreatic cancer tissues and cell lines in comparison with normal tissues was confirmed to be influenced by promoter methylation. Also hypermethylation of BNIP3, SPARC, TFPI2 and PENK promoters was observed in tumor samples but not in normal tissues which negatively correlated with their expression. Restoration of miR-377 resulted in a reduction of the expression of DNMT1 and reactivation of BNIP3 and SPARC genes via promoter demethylation. Furthermore, enhanced expression of miR-377 could significantly inhibit cell proliferation and induce apoptosis.

CONCLUSION

Our findings showed that miR-377 through targeting DNMT1 could reduce DNA methylation of some tumor suppressor genes and restore their expression in pancreatic cancer cells.

摘要

目的

本研究旨在探讨miR-377对胰腺癌细胞中DNMT1表达及癌症表型的影响。

材料与方法

采用实时定量聚合酶链反应、荧光素酶报告基因检测、MTT法及膜联蛋白-V/碘化丙啶双染法。

结果

与正常组织相比，胰腺癌组织和细胞系中miR-377表达降低，DNMT1（被证实为miR-377的靶标）水平升高，且这种差异受启动子甲基化影响。此外，在肿瘤样本中观察到BNIP3、SPARC、TFPI2和PENK启动子的高甲基化，而在正常组织中未观察到，这与其表达呈负相关。miR-377的恢复导致DNMT1表达降低，并通过启动子去甲基化使BNIP3和SPARC基因重新激活。此外，miR-377表达增强可显著抑制细胞增殖并诱导凋亡。