Objective: To investigate the common regulative effects of the Chinese drug Bailong and hexamethylen bisacetamide (HMBA) on expressions of oncogenes (c-H-ras and c-myc), and tumor suppressor genes (Rb, p53 and p21) of MGC80-3 in human cancer cell cycle.
Methods: Adopting RNA Northern Blot to survey the levels of gene expressions of MGC80-3 different phases cells treated with Bailong and HMBA respectively.
Results: In different phases of MGC80-3 cells treated with Bailong and differentiation inducer HMBA, expressions of oncogenes c-H-ras and c-myc were inhibited by over 50.0%, messenger kinase subspecies PKC-alpha gene is similar with the expression inhibition of oncogenes, except effect of Bailong on the G2 phase in cell cycle. Effect of Bailong differs greatly from HMBA in the expression of tumor suppression genes. The expression of Rb and p21 in cells treated by HMBA did not increase but were inhibited by 39.5% and 33.3% respectively in G1 phase. The level of Rb gene expression was decreased, too by 3.0% in S phase. Comparison with HMBA the expression of Rb and p21 genes were increased after treatment by Bailong in all cell cycle. But the effect of Bailong on the expression of p53 gene which was increased obviously by 125.0%-233.4% in majority phase of MGC80-3 cells is similar to HMBA.
Conclusion: (1) The effect of Bailong on the regulation of oncogenes and tumor suppressor gene is similar to HMBA but the effect of Bailong is better than that of HMBA. (2) Molecular mechanism of the Bailong or HMBA on the proliferative inhibition and differentiation of MGC80-3 related to regulation of the Bailong and HMBA on the oncogenes and tumor suppressor genes in cell cycle of MGC80-3.