miR-148b reverses cisplatin-resistance in non-small cell cancer cells via negatively regulating DNA (cytosine-5)-methyltransferase 1(DNMT1) expression

J Transl Med. 2015 Apr 28:13:132. doi: 10.1186/s12967-015-0488-y.

Abstract

Background: The emergence of drug resistance in cancer patients limits the success rate of clinical chemotherapy. MicroRNAs (miRNAs) may play a role in chemoresistance and may be involved in modulating of some drug resistance-related pathways in cancer cells. In this study, the involvement of microRNA-148b (miR-148b) and its roles in the development of chemoresistance in lung cancer are determined.

Methods: This study was performed in two lung cancer cell lines (A549 and SPC-A1). The levels of miR-148b and DNMT1 mRNA expression were determined by using Quantitative Real-Time PCR. Proteins of DNMTs are represented by western blot assay. Cell viability was assessed by MTT assay. Cell apoptosis was evaluated using flow cytometry.

Results: The data showed a down-regulated of miR-148b expression and evaluated methyltransferases (DNMTs) expression in cisplatin-resisted human non-small cell lung cancer (NSCLC) cell line-A549/DDP and SPC-A1/DDP compared with their parental A549 and SPC-A1 cell line. In transfection experiments, miR-148b mimics reduced the DNMT1 expression, as well as enhanced the sensitivity of cells to cisplatin and cisplatin-induced apoptosis in A549/DDP or SPC-A1/DDP cells. While miR-148b inhibitor increased DNMT1 expression, as well as attenuated the sensitivity of cells to cisplatin in A549 and SPC-A1 cells. miR-148b was showed to exert negative effect on DNMT1 expression by targeting its 3'UTR in A549/DDP and A549 cells. Importantly, silenced DNMT1 increases cisplatin sensitivity of A549/DDP cells and over-expressed DNMT1 reverses pro-apoptosis effect of miR-148b mimic.

Conclusions: miR-148b reverses cisplatin-resistance in non-small cell cancer cells via negatively regulating DNMT1 expression.

MeSH terms

  • Antineoplastic Agents / therapeutic use*
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / enzymology
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Cell Line, Tumor
  • Cisplatin / therapeutic use*
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNA (Cytosine-5-)-Methyltransferases / genetics*
  • Drug Resistance, Neoplasm / genetics*
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / enzymology
  • Lung Neoplasms / genetics
  • MicroRNAs / genetics*
  • Real-Time Polymerase Chain Reaction

Substances

  • Antineoplastic Agents
  • MIRN148 microRNA, human
  • MicroRNAs
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNA (Cytosine-5-)-Methyltransferases
  • DNMT1 protein, human
  • Cisplatin