Expression Of Glucose-Regulated Protein78in Hepatocellular Carcinoma And Its Clinical Significance

ObjectiveHepatocellular carcinoma(HCC) is the second most deadly cancer in the world, its incidence has been on the rise in worldwide. It is reported that about750,000new patients with liver cancer found each year. Because the onset of HCC conceals, early symptoms is not obvious, and may be quickly severe, most of the patients in our country has reached late stage when confirmed. So surgery opportunity is lost, treatment is difficult, the prognosis is poor. The study of domestic and foreign scholars discuss liver cancer drug resistance mechanism from different angles which become the hot topics, but still no breakthrough. In recent years, the endoplasmic reticulum stress (ERs) is gradually understanding the relationship related with cell survival. The endoplasmic reticulum(ER) function is essential for most cell activity and survival. ERs pathway is the third apoptosis signaling pathways independent of the mitochondrial pathway and the death receptor pathway. The upregulated expression level of glucose-regulated protein78(GRP78)/the immunoglobulin heavy chain-binding protein(BiP)often has been seen as ERs marker. Numerous studies show that ERs cells can regulate the activation/expression of promoting apoptosis molecules such as CHOP and caspase-12and promoting cell survival molecules such as GRP78,the balance of which is cells dicides the survival or apoptosis finally. Glucose regulating protein78plays an important role in protein folding and transfer process and endoplasmic reticulum stress response as a molecular chaperone, it is highly expressed in many kinds of tumor tissue. It is seldom reported that whether ERs was initiated in the development of cancer of the liver and GRP78expression level is in liver cancer tissue.To detect the expression of glucose-regulated protein78mRNA and protein in the tissue of hepatocellular carcinoma, demonstrating the activation of endoplasmic reticulum stress(ERs) and the unfolded protein response(UPR) in process of development of hepatocellular carcinoma and conjecturing its possible clinical significance.MethodsTo detect GRP78mRNA and protein expression of53case examples of hepatocellular carcinoma(17cases Well-differentiated carcinoma,23cases middle-differentiated carcinoma,13case poorly differentiated carcinoma,which were all confirmed by postoperative pathology) and19case normal liver tissues by immunohistochemistry, Real-time PCR and Western Blot.Results1. Immunohistochemistry results showed that the expression of GRP78in normal liver tissue and HCC tissueThe positive staining of GRP78protein is mainly located in cytoplasm, also observed in the cell membrane, not in nucleolus. Expression levels of GRP78in HCC tissues were significantly higher than normal liver tissues, which were associated with cellular differentiation degree. The lower the degree of differentiation, the higher the expression of GRP78protein.2. Real-time PCR results showed that the expression of GRP78in normal liver tissue and HCC tissueThe amplification dynamics curves of GRP78and beta actin is a typical s-type, the platform stage is gathered into a straight line. Melting curve shows unimodal type, which indicates that the specificity of the primers is good. After the correction of internal reference beta actin, to compare the relative content of GRP78mRNA in each group, the results shows that expression of GRP78mRNA of HCC tissue group is significantly higher than normal liver tissue, and is inversely proportional to the degree of hepatocarcinoma tissue differentiation.(P<0.05)3. Western blot results showed that the expression GRP78protein in normal liver tissue and HCC tissueThe GRP78protein bands are lighter in normal liver tissue, and the GRP78protein bands is brighter in hepatocellular carcinoma tissues. Compared with normal liver tissue, the expression quantity of GRP78increased significantly in HCC tissues (P<0.05). And it is inversely proportional to the degree of differentiation, namely: the differentiation degree is higher, the expression of quantity is the lower; on the other hand, it is the higher.ConclusionIt exists activation of ERs and UPR in process of growth of hepatocellular carcinoma. The expression of GRP78protein and its mRNA was accordant. it was higher in hepatoma tissue than in normal hepatic tissue. GRP78was speculated to be closely related to the biological characteristics of human hepatocellular carcinoma.