Reactivation of p21WAF1/CIP1 by saRNA inhibits proliferation, invasion and migration in gastric cancer cells

saRNA is a small molecular non-coding RNA, and it is proved to be effective in many cancer cells, such as prostate cancer cell, kidney tubular epithelial and breast cancer cell, but there has been no report on gastric cancer cells so far. dsP21-322, targeting p21(WAF1/CIP1) (p21) gene promoter located at position-322 (dsP21-322) relative to the transcription start site, was synthesized to explore the RNAa-induced reactivation effects on gastric cancer cell lines SGC-7901 and M-28. Besides, a dsControl saRNA was synthesized as a negative control. SGC-7901 and M-28 cells both were transfected with the different saRNAs or treated with lipofectamine2000 alone. real-time PCR and Western blot were used to determine the p21 mRNA and protein content, respectively. The proliferation of transfected cells was assessed by CCK-8. The invasive and migratory abilities were determined by using Transwell assays. The results showed that dsP21-322 caused a significant up-regulation of p21 expression in a time-and dose-dependent manner, and an obvious decrease in proliferation, invasive and migratory abilities compared with the control groups (P<0.01). This phenomenon provides gene therapy for gastric cancer or other malignant tumours and theoretical basis for subsequent RNA activation mechanism research.