The Role Of PKCα In The Multidrug Resistance Of Hepatocellular Carcinoma Cell Line HepG2.

【objective】HCC(hepatocellular carcinoma)is one of the important malignant tumor. There are many factors inducing hepatoma. The most common reason is virus hepatitis and liver cirrhosis. Generalized chems is one of the important therapy of the hepotoma. The generalized chems often failed in clinic because the hepatocellular carcinoma resisted to the multi-antitumor-drug. So the treat of hepatoma is still a hang-up. Many factors cause MDR. Many researchers thought that MDR appearance related to P-gp hyper-expression. People think that the P-gp educing the medicine pumping function is the most important reason. The P-gp can pump the medicine out of cells. PKC isozymes, especially PKCα, can influence the occurrence of the tumoer cell MDR. So it is helpful to find out the mechanisms of hepatoma multidrug resistant that the hepatoma'drug sensitivity changs when we chang the PKCαexpression. The research gave the clinical therapy of hepatoma-drug-resistant experiment basement.【Methods】1. Extraorgan synthetic DNA chain which including the aim frag integrated into retrovirus vector. 2. The retrovirus vector which including the aim DNA integrated into colibacillus. After the drug screening ,we got out the non-endotoxin plasmid.3. Mingled the non-endotoxin plasmid and virus-incasing cells together, using the electricity transfer instrument made the retrovirus vector integrating into the virus-incasing cells.4. After two weeks drug screening, we macroculltured the masccline cells.5. Using the virus supernate infected the HepG2.6. After two weeks drug screening, we macroculltures the live cells. Compared the drug sensitivity and growth velocity of the PMA treated HepG2 and siRNA treated HepG2 to the no-interfereing HepG2.【Results】1. Westernlot: The PKCαexpression was very little in siRNA interference's. It was no difference in idling interference's. The PMA could stimulate the expression of PKCα.2. The growth velocity of the siRNA interference's HepG2 was obviously stepping down ,whereas the gowth velocity of the PMA interference's HepG2 was faster than the no-interference HepG2. The growth velocity of the idling interference's HepG2 was no change.3. MTT result: Doing the experiment six times, we caculated the IC50 of every group to the EPI. Conteol group 10.2200±0.7805; siRNA interference group 6.4450±0.8549; idling interference group 10.1500±0.9343, PMA interference group 11.5400±1.3647. LSD-t analysis: compared to the control group, the siRNA interference group's and the PMA interference group's drug sensitivity to the EPI were all changing and had the satistical significance(p<0.05), while the idling interference had no difference.【Conclusion】 1. The siRNA frag used in this experiment was obviously cutting down the expression of PKCαof the HepG2.2. When the expression of PKCαstepped up, the drug sensitivity of the HCC was weakened; when the expression of PKCαcut down, the drug sensitivity of the HCC was strengthened and the tolerance to the drug was down regulated. To hint, suppressing the expression of the PKCαmaybe depress the toleration of HCC to antitumor drug and strengthen the Chems effect.