No abstract

MicroRNAs (miRNAs) have emerged as critical epigenetic regulators involved in cancer progression. miR-320a has been identified to be a novel tumour suppressive miRNA in colorectal cancer (CRC). However, the detailed molecular mechanisms are not fully understood. Here, we reported that miR-320a inversely associated with CRC aggressiveness in both cell lines and clinical specimens. Functional studies demonstrated that miR-320a significantly decreased the capability of cell migration/invasion and induced G0/G1 growth arrest in vitro and in vivo. Furthermore, Rac1 was identified as one of the direct downstream targets of miR-320a and miR-320a specifically binds to the conserved 8-mer at position 1140-1147 of Rac1 3'-untranslated region to regulate Rac1 protein expression. Over-expression of miR-320a in SW620 cells inhibited Rac1 expression, whereas reduction of miR-320a by anti-miR-320a in SW480 cells enhanced Rac1 expression. Re-expression of Rac1 in the SW620/miR-320a cells restored the cell migration/invasion inhibited by miR-320a, whereas knockdown of Rac1 in the SW480/anti-miR-320a cells repressed these cellular functions elevated by anti-miR-320a. Conclusively, our results demonstrate that miR-320a functions as a tumour-suppressive miRNA through targeting Rac1 in CRC.

Background Laparoscopic gastrectomy (LG) has been used as an alternative to open gastrectomy (OG) to treat early gastric cancer. However, the use of LG for advanced gastric cancer (AGC) has been in debate. Methods Literature retrieval was performed by searching PubMed, EMBASE, and the Cochrane library up to July 2014. Potential studies comparing the surgical effects between LG with OG were evaluated and data were extracted accordingly. Meta-analysis was carried out using RevMan. The pooled risk ratio and weighted mean difference (WMD) with 95 % confidence interval (95 % CI) were calculated. Results Overall, 26 studies were included in this metaanalysis. LG had some advantages over OG, including shorter hospitalization (WMD, -3.63, 95 % CI, -4.66 to -2.60; P \ 0.01), less blood loss (WMD, -161.37, 95 % CI, -192.55 to -130.18; P \ 0.01), faster bowel recovery (WMD, -0.78, 95 % CI, -1.05 to -0.50; P \ 0.01), and earlier ambulation (WMD, -0.95, 95 % CI, -1.47 to -0.44; P \ 0.01). In terms of surgical and oncological safety, LG could achieve similar lymph nodes (WMD, -0.49, 95 % CI, -1.78 to 0.81; P = 0.46), a lower complication rate [odds ratio (OR), 0.71, 95 % CI, 0.59 to 0.87; P \ 0.01], and overall survival (OS) and disease-free survival (DFS) comparable to OG. Conclusions For AGCs, LG appeared comparable with OG in short-and long-term results. Although more time was needed to perform LG, it had some advantages over OG in achieving faster postoperative recovery. Ongoing trials and future studies could help to clarify this controversial issue.