ABSTRACT
In order to investigate the inhibitory effects of all trans-retinoitc acid (ATRA) on differentiation and apoptosis of Walker-256 hepatocellular carcinoma cells and the therapeutic effects of ATRA combined with transarterial chemoembolization (TACE) on rat Walker-256 transplanted hepa-tocarcinoma, Walker-256 hepatocarcinoma cell lines were treated with ATRA at different concentrations. After culture for 48 h, the inhibitory rate of cell proliferation was determined by MTT assay; the changes of Fas and Bcl-2 mRNA expression were determined by RT-PCR, and the expression levels of Caspase3 and Caspase8 proteins were detected by Western blot. Twenty-seven Wistar rat models of hepatocarcinoma were set up successfully by implanting Walker-256 cell lines. The tumor volume at the 11th day after implantation (Vpreoperatioi) was measured by magnetic resonance imaging (MRI). The 27 rats were randomly and equally divided into three groups, and the therapy scheme was performed as follows: group A (ATRA 0.1 mg+mitomycin 0.05 mL+lipiodol 0.05 mL+gelfoam powder 0.025 mg); group B (mitomycin 0.05 mg+lipiodol 0.05 ml+gelfoam 0.025 mg; group C (0.9% NaCl 0.2 mL). After another 11 days, MRI was performed once again to measure the tumor volume (Vpostoperation)- The expression of factor VIII and Ki-67 in the tumor tissues was detected by immuno-histochemistry. The results showed that ATRA could suppress proliferation of Walker-256 cell lines. After treatment of Walker-256 cell lines with ATRA, the expression of Fas mRNA was significantly up-regulated and the Bcl-2 mRNA was significantly down-regulated by ATRA at the concentration of 10 umol/L as compared with the control group (P<0.05). After treatment with 10 umol/L ATRA for 48 h, the Caspase3 and Caspase8 were significantly activated as compared with the control group (P<0.05). Significant difference existed in growth rate among the three groups (P<0.01) and between either two groups (P<0.05). The expression rate of factor VIII and Ki-67 was gradually increased from group A, group B to group C. The study suggests that ATRA could inhibit the proliferation of Walker-256 cells and the effectiveness of the combined therapy (ATRA+TACE) for treating transplanted hepatoma of rats is superior to that of TACE alone.
ABSTRACT
This study investigated the inhibitory effect of the extract of fungi of Huaier (EFH) on the growth of hepatocellular carcinoma (HCC) cells.Hep-G2 cells,a human HCC cell line,were cultured in DMEM containing 10% fetal bovine serum and treated with EFH of different concentrations (1,2,4,8 mg/mL) for 24,48 and 72 h respectively.The apoptosis rate of the cells was flow cytometrically measured.Thirty-six tumor-bearing New Zealand rabbits were randomly divided into 3 groups:group A (control group),in which the rabbits were infused with 0.2 mL/kg normal saline via the hepatic artery;group B (transhepatic artery chemoembolization [TACE] group),in which the rabbits were given lipiodol at 0.2 mL/kg plus MMC at 0.5 mg/kg via the hepatic artery;group C (TACE +EFH group),in which EFH (500 mg/kg) were orally administered after TACE.Two weeks after TACE,the rabbits were sacrificed and the implanted tumors were sampled.The tumor volume and the necrosis rate were determined.The tumor tissues were immunohistochemically detected for the expressions of factor Ⅷ,VEGF,P53,Bax and Bcl-2.The microvessel density (MVD) was calculated by counting the factor Ⅷ-positive endothelial cells.Our results showed that after treatment with EFH,the apoptosis rate of Hep-G2 cells was enhanced in a concentration- and time-dependent manner.Two weeks after the treatment,the average tumor volume,the necrosis rate and the growth rate of the implanted tumor in group C were significantly different from those in groups A and B (P<0.05).MVD and VEGF expressions were significantly decreased in the group C when compared with those in groups B (P<0.05 for all).The Bax expression was weakest in group A and strongest in group C.The expressions of P53 and Bcl-2 were minimal in group C and maximal in group A.There were significant differences in the expressions of P53,Bax and Bcl-2 among the 3 groups (P<0.05 for all) and there was significant difference between group B and group C (P<0.05).It was concluded that EFH could suppress not only the growth of HCC cells but also tumor angiogenesis and it can induce the apoptosis of HCC cells.EFH serves as an alternative for the treatment of HCC.