Abstract: Objective To investigate the effect of long non-coding RNA small nucleolar RNA host gene l (SNHG1) targeting microRNA-101-3p (miR-101-3p) on the drug-resistance of oxaliplatin (OXA) in gastric cancer cells (BGC-823) and its possible mechanism. Methods The gastric cancer cells BGC-823 cells and oxaliplatin-resistant BGC-823/OXA cells were cultured in vitro, the SNHG1 interference RNA (si-SNHG1 group) and negative control (si-NC group) were transfected into BGC-823/OXA drug-resistant cells, and the blank control group  was set up at the same time. After transfection, BGC-823/OXA cells were treated with 10 μmol/L oxaliplatin, and classified as the si-NC+OXA group and si-SNHG1+OXA group, respectively. The expressions of lncRNA SNHG1, miR-101-3p and MDR1 mRNA were detected by RT-qPCR; the cell proliferation was detected by MTT assay; the cell apoptosis was detected by flow cytometry; the protein expressions of P-gp and MRP proteins were detected by Western blot; the targeting relationship between lncRNA SNHG1 and miR-101-3p was verified by the double luciferase reporter assay. Results Compared with BGC-823 cells, lncRNA SNHG1 was highly expressed and miR-101-3p was low expressed in BGC-823/OXA cells (both P<0.001). The prediction of starBase database showed that lncRNA SNHG1 had binding sites with miR-101-3p 3'UTR region. The luciferase activity of SNHG1-wt+ miR-101-3p-mimics group was lower than that of SNHG1-wt +miR-101-3p-NC group (P<0.001). Compared with si-NC group, the expression levels of lncRNA SNHG1 mRNA, MDR1 mRNA, P-gp protein, MRP protein and cell survival rate in si-SNHG1 group were decreased ( all P<0.05), and the apoptosis rate and expression of miR-101-3p were increased (both P<0.05). Compared with si-NC+ OXA group, the cell survival rate, protein expression levels of P-gp and MRP in si-SNHG1+OXA group were decreased, and the apoptosis rate was significantly increased (all P<0.05). Conclusions LncRNA SNHG1 inhibits the proliferation of gastric cancer BGC-823 cells and induces apoptosis by targeting miR-101-3p, and enhances oxaliplatin resistance. LncRNA SNHG1 may be a potential molecular target for gastric cancer.

Key words: Gastric cancer, LncRNA SNHG1, miRNA-101-3p, Oxaliplatin, Drug-resistance