Unconjugated
Gene therapy has great potential for human diseases. Development of efficient delivery systems is critical to its clinical translation. Recent studies have shown that microbubbles in combination with ultrasound (US) can be used to facilitate gene delivery. An aim of this study is to investigate whether the combination of US-targeted microbubble destruction (UTMD) and polyethylenimine (PEI) (UTMD/PEI) can mediate even greater gene transfection efficiency than UTMD alone and to optimize ultrasonic irradiation parameters. Another aim of this study is to investigate the biological effects of PHD2-shRNA after its transfection into H9C2 cells. pEGFP-N1 or eukaryotic shPHD2-EGFP plasmid was mixed with albumin-coated microbubbles and PEI to form complexes for transfection. After these were added into H9C2 cells, the cells were exposed to US with various sets of parameters. The cells were then harvested and analyzed for gene expression. UTMD/PEI was shown to be highly efficient in gene transfection. An US intensity of 1.5 W/cm2, a microbubble concentration of 300μl/ml, an exposure time of 45s, and a plasmid concentration of 15μg/ml were found to be optimal for transfection. UTMD/PEI-mediated PHD2-shRNA transfection in H9C2 cells significantly down regulated the expression of PHD2 and increased expression of HIF-1α and downstream angiogenesis factors VEGF, TGF-β and bFGF. UTMD/PEI, combined with albumin-coated microbubbles, warrants further investigation for therapeutic gene delivery.
Phosphatase of regenerating liver-3 (PRL-3) has been implicated in controlling cancer cell invasiveness. Deregulated expression of PRL-3 is involved in cancer progression and predicts poor overall survival. Recent studies have revealed critical roles for microRNAs in various cellular processes, including tumorigenic development. In this study, we aimed to explore the linkage between PRL-3 and microRNAs in gastric cancer. We found that PRL-3 transcript levels were positively correlated with miR-210 levels in gastric cancer tissues. In gastric cancer cells, PRL-3 upregulated miR-210 expression in a HIF-1α-dependent fashion under normoxia and hypoxia. In addition, PRL-3 activated NF-κB signaling and promoted HIF-1α expression through modulating phosphorylation of p65. NF-κB signaling, HIF-1α, and miR-210 partially contributed to PRL-3-induced migration and invasion. Furthermore, the levels of PRL-3, HIF-1α, and miR-210 transcripts inversely affected the overall survival of gastric cancer patients. Our work identified the existence of a PRL-3-NF-κB-HIF-1α-miR-210 axis, thus providing new insight into the role of PRL-3 in promoting gastric cancer invasiveness.
KEY MESSAGE:
PRL-3 regulates microRNA in gastric cancer. PRL-3 elevates hsa-miR-210 by upregulating HIF-1α. PRL-3 activates a NF-κB-HIF-1α-miR-210 axis by enhancing the phosphorylation of p65. PRL-3 promotes cell migration and invasion via the NF-κB-HIF-1α-miR-210 axis. High levels of PRL-3 and miR-210 are related with poor OS in gastric cancer.
