中药白龙片与HMBA对人胃癌不同周期细胞癌基因与抑癌基因表达调控的共性研究

目的：探讨复方中药白龙片与环六亚甲基二乙酰胺（HMBA）对人胃癌（MGC80－3）细胞不同周期时相细胞癌基因c-H-ras、c-myc，抑癌基因Rb、p53和p21以及PKC－α基因表达的影响。方法：采用Northern印迹法检测基因表达情况。结果：MGC80－3细胞不同周期时相用中药白龙片或HMBA处理，癌基因c-H-ras和c-myc的表达下降，多数周期的抑制率达50．0％以上；促增殖的信使激酶亚类PKC－α基因的表达基本与癌基因表达抑制相似。两类药物对抑癌基因的影响则有显著差异。HMBA处理细胞后，Rb与p21在G1期的表达不是增加而是下降，抑制率分别为39．5％和33．3％，Rb在S期也抑制3．0％。而中药白龙片对Rb与p21在各个周期内均是促进表达的作用，有的周期升高1－2倍以上。但是中药白龙片对抑癌基因p53的表达作用和HMBA都很近似，各个周期都有显著增加，多数时相达125．0％－233．4％。结论：（1）中药白龙片对癌基因和抑癌基因的调节作用基本与诱导分化剂HMBA相似，但中药白龙片的作用优于HMBA。（2）中药白龙片或HMBA对MGC80－3细胞增殖抑制和促分化作用的分子机理和两类药物对细胞周期内癌基因与抑癌基因调节相关。

Study on Common Character of Regulative Molecular Mechanism of Chinese Drug Bailong and Hexamethylen Bisacetamide in Human Cancer Cell Cycle and Their Oncogene and Tumor Suppressor Gene Expression

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.