Grp78 promotes the invasion of hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Glucose regulated protein 78 (Grp78) is involved in the invasion and metastasis in many human cancers including gastric cancer, breast cancer, prostate cancer. But the role of Grp78 in the invasion of human hepatocellular carcinoma has not been reported. In this article, we examined if Grp78 was associated with the invasion of hepatocellular carcinoma and explored the possible underlying mechanism.</p> <p>Methods</p> <p>The Grp78 and FAK expression levels in 44 patients with hepatocellular carcinoma were examined using immunohistochemistry. Grp78 overexpressing SMMC7721 cells were established by pcDNA3.1 (+)-Grp78 transfection and screened by G418. Grp78 and FAK levels in Grp78 overexpressing cells were down-regulated by siRNA transfection. The invasion status of tumor cells was evaluated by transwell assay in vitro, and chick embryo metastasis model in vivo. Cell spreading was determined by cell spreading assay, and quantitatively measured by Orisis software HUG. Grp78, pY397 FAK, pY576/577 FAK and FAK levels were detected by western blot. RhoA activity was detected by GST pulldown assay. The distribution of actin cytoskeleton was observed by fluorescent staining.</p> <p>Results</p> <p>Grp78 expression levels in 44 patients with hepatocellular carcinoma were negatively correlated with tumor grading, and positively correlated with portal invasion and intra-hepatic invasion. Overexpression of Grp78 in SMMC7721 cells promoted the invasion of cancer cells in vitro and in vivo, and this increase in tumor cell invasion was blocked by Grp78 siRNA knockdown. Our results also revealed that overexpression of Grp78 in SMMC7721 cells accelerated the process of cell spreading and promoted lamellipodia formation. Further analysis showed that overexpression of Grp78 in SMMC7721 cells increased pY397 and pY576/577 levels of FAK. Grp78 siRNA knockdown decreased FAK activation and activity. Our results also revealed that Grp78 overexpression in SMMC7721 cells decreased RhoA-GTP level, and Grp78 siRNA knockdown rescued RhoA-GTP level in Grp78 overexpressing cells, indicating Grp78 inhibited RhoA activity in hepatocellular carcinoma cells. Furthermore, overexpression of Grp78 in SMMC7721 cells increased phospho-p190RhoGAP level. FAK siRNA knockdown in Grp78 overexpressing cells reversed phospho-p190RhoGAP level. These data suggested that Grp78 inhibited RhoA activity by up-regulated phospho-p190RhoGAP level and Grp78 mediated p190RhoGAP phosphorylation is FAK dependent.</p> <p>Conclusion</p> <p>Grp78 promoted the invasion of hepatocellular carcinoma both in vitro and in vivo. Overexpression of Grp78 in hepatocellular carcinoma cells enhanced the activation and activity of FAK which negatively regulated Rock kinase activity by promoting the phosphorylation of p190RhoGAP.</p

Combination of Ginsenoside Rg1 and Bone Marrow Mesenchymal Stem Cell Transplantation in the Treatment of Cerebral Ischemia Reperfusion Injury in Rats

Background/Aims: The present study aims to explore the protective role and mechanism of ginsenoside Rg1 combined with bone marrow mesenchymal stem cell (BMSC) transplantation for cerebral ischemia reperfusion injury (CIRI) in rat brain. Methods: One hundred twenty male SD rats were randomly divided into a sham group, an Ischemia Reperfusion (IR) group, an IR group treated with BMSC transplantation (IR+BMSCs), an IR group treated with Rg1 (IR+Rg1), and an IR group treated with BMSC transplantation and Rg1 (IR+Rg1+BMSCs). To establish a CIRI model, right middle cerebral artery embolization was used. The neurological score, 2,3,5-triphenyltet-razolium chloride monohydrate (TTC) staining and brain water content were detected to assess the treatment efficiency. HE staining and TUNEL were used to explore the pathologic changes and apoptosis. To explore the protein levels of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP), immunofluoresence was utilized. Western blotting was used to explore apoptosis-related proteins such as Bcl-2 and Bax. Results: Compared with the sham group, the IR group demonstrated obvious ischemic changes, such as significant neurologic defects and enhanced brain water content. The Rg1 treatment resulted in an obvious decrease in cell apoptosis and improved ischemic conditions. By BMSC transplantation, the transplanted cells could be differentiated into neurons and glial cells, which also improved cerebral ischemia. More importantly, the IR+Rg1+BMSCs group showed the best treatment efficiency with reduced cell apoptosis and better cerebral recovery. Conclusions: The Rg1 treatment resulted in an obvious decrease in cell apoptosis, while the transplanted cells could be differentiated into neurons and glial cells, which also improved cerebral ischemia