LncRNA CRNDE is involved in radiation resistance in hepatocellular carcinoma via modulating the SP1/PDK1 axis

 Kai-Yun Chen, Shu-Guang Zhu, Ji-Wen He, Xiao-Peng Duan

Abstract:

Hepatocellular carcinoma (HCC) is defined as a universal malignancy while radiation therapy is the effective treatment for it. This study validated the mechanism of long non-coding RNA (lncRNA) colorectal neoplasia differentially expressed gene (CRNDE) in radiation resistance in HCC. LncRNA CRNDE upregulation was detected in HCC cells. The radiation-resistant cell strains Huh7R and SNU-387R were established. After silencing lncRNA CRNDE, the cell colony formation ability, cell activity, apoptosis, cell cycles, and γ-H2AX positive rate in Huh7R and SNU-387R were detected. Silencing lncRNA CRNDE decreased the cell activity, colony formation ability, and cell number in the G2 phase and facilitated DNA damage and apoptosis. The binding relations of specificity protein 1 (SP1) with lncRNA CRNDE and 3-phosphoinositide dependent protein kinase 1 (PDK1) were verified. LncRNA CRNDE regulated PDK1 transcription by binding to transcription factor SP1. PDK1 overexpression partially reversed the inhibition of silencing lncRNA CRNDE on radiation resistance in HCC cells. The transplanted tumor mouse model was established and showed that silencing lncRNA CRNDE decreased tumor volume and weight and Ki67-positive cells in HCC mice in vivo. Collectively, lncRNA CRNDE was upregulated in HCC cells and promoted PDK1 transcription by binding to SP1, thus enhancing radiation resistance in HCC cells.