Abstract 1418: Brother of regulator of imprinted sites (BORIS) inhibits cisplatin induced DNA damage in non-small-cell lung cancer

Abstract

Abstract Cisplatin (DDP) treatment is primary modality for non-small-cell lung cancer (NSCLC) chemotherapy. However, patients benefited from DDP treatment limitedly due to the DDP resistance. Brother of Regulator of Imprinted Sites (BORIS, CTCFL) is the paralogue of CCCTC-binding factor (CTCF) and expressed abnormally in most type of cancers and is potential tumor target for breast, cervical carcinoma and lung cancer. However, the funciton of BORIS on carcinoma is unrevealed. In our previous study, we found that BORIS suppressed apoptosis and resisted 5-FU (Fluorouracil) treatment in colorectal cancer. As either 5-FU or DDP induces DNA damage and apoptosis of carcinoma cells, BORIS perhaps resists DDP treatment too. Based on the prevalent expression of BORIS and the high incidence of DDP resistance in NSCLC, we proposed that BORIS contributed to DDP resistance by suppressing DNA damage in NSCLC. We collected RNA sequencing data of 156 NSCLC patients who received DDP chemotherapy from The Cancer Genome Atlas and analyzed the expressions of BORIS. We found high BORIS expression correlated with short survival in NSCLC patients who received DDP chemotherapy. BORIS expression declined from prospective to retrospective collected tissue which responded to DDP chemotherapy. It suggested the probability function of BORIS on DNA damage repair. In cell cultured lung cancer cell lines, BORIS was silenced or over-expressed including DDP resistant cell line. It indicated that A549/DDP (DDP resistant A549 cell line) expressed relative higher BORIS than A549 parental cells and BORISexpression levels correlated with cell viability. H1299 and A549/DDP expressed comparative BORIS and growed comparativly. H460 and A549 expressed relative lower BORIS levels and grew slower than H1299 and A549/DDP. BORIS knockdown inhibited the proliferation of NSCLC cells, enhanced the sensitivity of A549/DDP and H1299 to DDP treatment and induced DNA damage. Reversely DDP induced DNA damage was suppressed by BORIS over-expression. The excision repairing gene ERCC1, which is regulated by BORIS, might be the assistant for DDP resistance. Either high expression of BORIS or ERCC1 indicated short survival rates of NSCLC patients. Our data suggested that BORIS suppressed DNA damage and promoted the progression of NSCLC and DDP resistance, which indicated its potential in NSCLC prognosis and therapy. Citation Format: Yongfei Song, Chao Li, Mengdie Fang, Juan Ren, Jianfei Fang, Xiaoju Wang, Yanmei Zhang. Brother of regulator of imprinted sites (BORIS) inhibits cisplatin induced DNA damage in non-small-cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1418.