SiRNA-Mediated lncRNA ANRIL Knockdown Enhances the Sensitivity of Gastric Cancer Cells to Doxorubicin

Background: Long non-coding RNAs (IncRNAs) play pivotal roles in carcinogenesis and the development of drug resistance in various malignancies. Objectives: The current study aimed to explore the impact of antisense non-coding RNA in the INK4 locus (ANRIL) silencing on proliferation and the sensitivity of KATO III gastric cells to the doxorubicin as a common chemotherapeutic agent. Methods: The KATO III cells were transfected with ANRIL siRNA (si-ANRIL) using Lipofectamine (TM) 2000 reagent. Following that, the relative ANRIL levels were determined by quantitative Real-Time PCR. Trypan blue assay was conducted to observe the tumor cell proliferation following the transfection. Moreover, the MTT assay was performed to identify the cytotoxic effects of doxorubicin and si-ANRIL alone or in combination on KATO III cells. The effects of si-ANRIL/doxorubicin on KATO III cells migration and apoptosis were assessed by wound healing assay and ELISA cell death method, respectively. Results: The results showed that the si-ANRIL significantly diminished ANRIL expression level in a time-dependent manner contributing to the distinct repression of cell growth and enhanced apoptosis. Furthermore, the si-ANRIL synergistically elevated the cytotoxic impacts of doxorubicin. Additionally, the ANRIL down-regulation dramatically promoted its induction of apoptosis. Moreover, KATO III cells transfected with si-ANRIL and exposed with doxorubicin revealed significantly reduced invasion capability and enhanced apoptosis rate. Conclusion: These results demonstrated that the knock-down of lncRNA ANRIL could be a potential therapeutic strategy to trigger apoptosis and circumvent doxorubicin-resistance.