Regression of A549 lung cancer tumors by anti-miR-150 vector.

microRNAs (miRNAs) have been shown to play a role in cancer. Antisense oligonucleotides can bind directly to miRNAs and block their activity, which are generally named anti-miRNAs. To suppress A549 cell proliferation in vitro and in vivo by anti-miRNAs, an anti-miR-150 expression vector (PR-ASO-150), regulated by the H1 promoter and containing a 'TTTTT' sequence following a hairpin to stop transcription, was constructed. A549 cell proliferation in vitro or in nude mice was observed after PR-ASO-150 treatment. Our results showed that miR-150 expression was inhibited and the growth inhibition rate of A549 cells was higher in the PR-ASO-150-treated group compared with the control, which indicated that PR-ASO-150 could inhibit A549 cell proliferation by regulating miR-150 expression. Following establishment of A549 cancer cell xenografts in nude mice, PR-ASO-150 was delivered intratumorally to investigate the suppressive action to tumor proliferation by regulating miR-150 expression. The results indicate that the tumor volume and weight were lower compared to the control group. Our results further showed that p53 expression was higher after tumor tissue was treated with PR-ASO-150, indicating that up-regulation of p53 contributed to the suppression to tumor growth. Our study provides a novel strategy for cancer therapy through the development of anti-miRNAs.