| Liver cancer is derived from the liver cell or intrahepatic bile duct epithelial cells of malignant tumors, including primary hepatocellular carcinoma accounts for more than85%of all malignant tumors of liver. Hepatocellular carcinoma(hepatocellular, carcinoma, HCC) in the incidence of the common malignant tumors in the highest fifth, because of the difficulties in early diagnosis,malignant degree is high, and it is difficult to carry out effective radiotherapy and chemotherapy on its. About700000cases of the world each year a new diagnosis of HCC patients, of which more than50%of the cases occurred in China. Hepatocellular carcinoma with high malignancy, rapid progress, the prognosis is poor, is the third leading cause of cancer-related death worldwide.Only operation treatment can not meet the clinical needs, the main treatment for the current operation excision, including chemotherapy, interventional therapy, but the overall treatment effect is not satisfactory, because the HCC early lack of specific symptoms, so many patients find that disease has lost the treatment of treatment, therefore, HCC has become the cause of global in malignant tumors, third died, killed more than600000people each year, a serious threat to human life and health. Therefore, to elucidate the molecular mechanism of the occurrence and development of HCC and its recurrence and metastasis, further finding has important significance for antitumor effective method for the treatment of HCC.Opioid receptor has been one of the research hotspots in the field of scientific research, the mu opioid receptor (MOR) belongs to the opioid receptor family,is one of the three classical opioid receptors, which is closely related with the survival and proliferation of cells. Mu receptor is composed of398amino acid residues, its N terminal contains5N-glycosylation sites. In the new study found that the effect of tumor progression of mu opioid receptor. The study found the mu opioid receptor is highly expressed in liver cells, and involved in liver tumor,acute hepatitis, occurrence and development of liver fibrosis of liver diseases.And the first cloning of the Delta opioid receptor (DOR) one of the three opioid receptors belong to the classic, MOR and DOR belong to G protein coupled receptor, DOR is composed of372amino acid residues. Having expressed in many organs and tissues in the human body. In recent years, with the function of DOR gradually in-depth study, found in the liver disease occurrence,development process plays an important role in the regulation of. DOR mainly relates to the survival and proliferation of cells. But in times before, our research has shown that DOR is expressed in liver cells and tissues, and found that at the same time the activation DOR against the apoptosis of hepatic cells. Activation of these protective effects of DOR due to DOR sequences.ERK is in the MAPK family found first know most members. ERK consists of two isomers of ERK1and ERK2, two phospho acceptor sites that tyrosine and threonine separated by glutamic acid residues, so its phosphorylation site motif is TEY. At present, P38and JNK belong to the "MAPK stress induced".The study found, ERK signal transduction pathway involving a wide range of biological activities and can cause cell growth, proliferation and apoptosis. Studies have shown that Delta receptors to activation of the ERK pathway with G-protein-or-arrestin-dependent mechanism. Protein kinase C (PKC) is a classic type of threonine kinase and widely expressed in human cells. In the resting state, the intracellular PKC with invalid form is distributed in the cytoplasm. External factors to stimulate, PKC from cytosol to membrane and activated. PKC signal transduction pathway is involved in a wide range of biological activities, especially the proliferation and differentiation of variouscell mediated. The study found, PKC is involved in the protection of preconditioning on liver ischemia. Normal cells and liver tumor cell proliferation and apoptosis is closely related with PKC Our previous studies showed that,DOR and phosphorylated PKC share a common pathway.At present, about the research in liver cancer MOR and DOR is less, there are many problems waiting for people to explore. In our study, using the Westernblot, immunohistochemistry, confocal microscopy and flow cytometry were used to study the expression of DOR in human hepatocellular carcinoma and itsregulation of apoptosis process from protein level role.Objective:To observe the expression of DOR and MOR in liver cancer tissues and cell lines. The effect of DOR on the apoptosis of human hepatocellular carcinoma cell regulation and signal transduction mechanism.Methods:1samples from20cases of hepatocellular carcinoma tissues andnormal liver cell lines, expression using immunohistochemistry, Western blotand confocal microscopy to detect DOR, MOR protein. The selection of hepatoma cell lines, cell proliferation was detected by MTT assay, cell apoptosis was detected by flow cytometry analysis, Western protein expression of blot, the selection of hepatoma cell lines, by detecting changes in the mitochondrial membrane potential of flow cytometry analysis, the expression of Western blot, coimmunoprecipitation detecting interactions between protein.Results:the expression of MOR and DOR were in hepatocellular carcinoma.MOR and DOR are mainly distributed in the human hepatoma cell membrane and cytoplasm. in addition of hydrogen peroxide in medium could induce apoptosis of hepatoma cells cultured human hepatoma cells, and the number of apoptosis with hydrogen peroxide concentration increases. Apoptosis of hepatoma cells excited DOR inhibition caused by H2O2, and activation of DOR can induce PKC protein and its phosphorylation level increases, the down-regulation of DOR may have the opposite effect, confirmed the interaction between DOR and PKC coimmunoprecipitation. Down regulation of DOR can lead to ERK protein and phosphorylation levels decreased, PKC inhibitors can produce the same effect, also found that the mitochondrial membrane potential decreased, Bcl-2and Cyt decreased expression of C,increased expression of Bax.Conclusion:Expression of DOR and MOR in hepatocellular carcinoma tissues and cells,mainly located in the cell membrane and cytoplasm. DOR hepatocellular carcinoma cells were apoptosis process control. DOR on hepatocellular apoptosis and regulation of PKC-ERK and mitochondrial signal transduction pathway. |
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