Long noncoding RNA DPP10-AS1 promotes malignant processes through epigenetically activating its cognate gene DPP10 to predict poor prognosis in lung cancer patients

Abstract

Background Long noncoding RNAs (lncRNAs) play oncogenic or tumor-suppressive roles in various cancers. However, the epigenetic modification of lncRNA and its cognate sense gene in lung cancer remain largely unknown.Methods : qRT-PCR and Western blot were conducted to detect the expressions of DDP10-AS1 and DPP10 expression in lung cancer cell lines and tissues. The impact of DDP10-AS1 on DPP10 expression, cell growth, invasion, apoptosis and in vivo tumor growth were investigated in lung cancer cells by Western blot, rescue experiments, colony formation, flow cytometry and xenograft animal experiment.Results A novel antisense lncRNA, DPP10-AS1, is found to be highly expressed in cancer tissues and the upregulation of DPP10-AS1 predicts poor prognosis in lung cancer patients. Notably, DPP10-AS1 promotes lung cancer cell growth, colony formation, cell cycle progression and represses apoptosis in lung cancer cells by upregulating DPP10 expression. Additionally, DPP10-AS1 facilitates lung tumor growth via upregulation of DPP10 protein in xenograft mouse model. Importantly, DPP10-AS1 positively regulates DPP10 gene expression and they are coordinately upregulated in lung cancer tissues. Mechanically, DPP10-AS1 associates with DPP10 mRNA but does not enhance DPP10 mRNA stability. Hypomethylation of DPP10-AS1 and DPP10 contributes to their coordinate upregulation in lung cancer.Conclusions These findings indicate that the upregulated antisense lncRNA DPP10-AS1 promotes lung cancer malignant processes and facilitates tumorigenesis by epigenetically regulating its cognate sense gene DPP10, and DPP10-AS1 may act as a candidate prognostic biomarker and a potential therapeutic target in lung cancer.