Hypermethylation of ATP‐binding cassette B1 (ABCB1) multidrug resistance 1 (MDR1) is associated with cisplatin resistance in the A549 lung adenocarcinoma cell line

Abstract

Development of multiple drug resistance has been attributed to the overexpression of the ATP-binding cassette B1 (ABCB1) gene. In this study, the major purpose was to assess the expression and methylation levels of ABCB1 in human lung adenocarcinoma and to reveal the relationship between these processes and acquisition of cisplatin (DDP) resistance in the human cancer cell line A549. Methylation and expression levels of the ABCB1 gene ABCB1 in clinical human lung tissue were assessed using bisulphite sequencing, reverse transcription real-time PCR (RT -PCR) and Western blot methods. Cell viability, DDP resistance and apoptosis of A549 cells were evaluated using the Cell Counting Kit-8 and fluorescence-activated cell sorter analysis. Our results showed that the onset of resistance to the cisplatin analogue, DDP, was associated with hypermethylation of the ABCB1 gene. Expression of the ABCB1 gene was enhanced at both mRNA and protein levels. Treatment with 5-Aza-C contributed to the hypomethylation of the ABCB1 gene and decreased ABCB1 protein expression in A549 cells. In conclusion, this in vitro and human tissue study of lung adenocarcinoma cells demonstrated that hypermethylation of the ABCB1 gene correlated with increased gene expression and was associated with the acquisition of resistance to the cisplatin analogue, DDP in human lung adenocarcinoma cells. Taken together, our study highlighted the connection between increased ABCB1 methylation level and upregulated expression of the gene in lung cancer. Moreover, the abnormally high expression of ABCB1 in A549 cells contributed to the development of the DDP resistance.

MDIG promotes cisplatin resistance of lung adenocarcinoma by regulating ABC transporter expression via activation of the WNT/β‑catenin signaling pathway

“…In order to investigate the molecular mechanism of MDIG-promoted DDP resistance in lung adenocarcinoma cells, the present study examined the basal expression levels of efflux pump ABC transporters in A549 and A549/DDP cells, and it was revealed that the mRNA and protein expression levels of ABCB1, ABCC1 and ABCG2 in A549/DDP cells were significantly higher compared with those of A549 cells. This was consistent with previous studies (32)(33)(34), indicating that efflux pump ABC transporters are involved in DDP resistance in lung adenocarcinoma cells. To further investigate whether MDIG affected the resistance of lung adenocarcinoma to DDP by regulating the expression levels of the ABC transporter family, MDIG was overexpressed and silenced in A549 and A549/DDP cells, and the mRNA and protein expression levels of the ABC transporters were subsequently determined by RT-qPCR and western blot analysis, respectively.…”

Progesterone-Calcitriol Combination Enhanced Cytotoxicity of Cisplatin in Ovarian and Endometrial Cancer Cells In Vitro

“…Our results revealed significantly higher levels of ABC transporters in ovarian and endometrial cancer cells. These findings are consistent with previous studies [53][54][55], suggesting that the efflux pump ABC transporters are involved in DDP resistance in cancer cells. Additionally, following the treatment of cancer cells with progesterone-calcitriol combination, the expression levels of ABC transporters were significantly lower compared to the control cells.…”

Aberrant DNA Methylation of ABC Transporters in Cancer

“…Thirty-one studies have investigated the downstream region (DSR) of ABCB1 ( Figure 1 ). Among them, seven studies have targeted each of the 66 CpGs in the ABCB1 downstream promoter by BS [ 126 , 127 , 128 , 129 , 130 , 131 , 132 ]. Other studies applying BS have targeted 56 [ 133 ], 25 [ 134 ], 19 [ 135 ], or eleven [ 136 , 137 ] CpGs.…”