Abstract:
Purpose: To evaluate in vitro (using human hepatoma HepG2 cells) and in vivo (using mouse liver with diethlynitrosamine (DEN)-induced hepatocarcinogenesis) effect of a standardized decoction on the expression of p53 (tumour suppressor) and p21 (cyclin kinase inhibitor) genes with the long-term goal of developing the formulation into a globally acceptable therapy for hepatocellular carcinoma (HCC). Methods: The effect of the decoction on (a) mRNA and (b) protein expression of p53 and p21 genes in HepG2 cells and mouse livers with DEN-induced early hepatocarcinogenesis were evaluated by (a) reverse transcription PCR (RT-PCR) and (b) immunohistochemical and Western blot analysis, respectively. Results: The results demonstrated that the decoction significantly (p < 0.001) enhanced the expression of p53 and p21 genes in a time- and dose-dependent manner in HepG2 cells. A dose of 75 µg/ml significantly increased p53 mRNA at 24 and 48 h and p21 mRNA at 12, 24, 48 h of incubation with the decoction (p < 0.01). Induction of hepatocarcinogenesis in mice significantly increased hepatic expression of both p53 and p21 compared to distilled water control (p < 0.001), while treatment with the decoction further enhanced expression of both genes in DEN-induced hepatocarcinogenesis (p < 0.01). Conclusion: Overall, the findings demonstrate that the decoction may mediate its reported antihepatocarcinogenic effect, at least in part, through the modulating activities of genes involved in tumour suppression and cell cycle arrest.
