Objective: To study the effect of compound Chinese drug Bailong on the transcription of Cyclin Dependent Kinase Inhibitor (CKI) p16INK4a, p21 and Rb, c-myc genes, and the relationship between gene expression and cAMP-PKA pathway.
Methods: Using the traditional molecular biology methods (cell synchronization, molecular hybridization--Western blotting, Northern blotting, etc.) examine the gene expression.
Results: Bailong promoted the expression (both mRNA and protein) of p16INK4a obviously in G1 phase cells. When prekallikrein (PKA) inhibitor was added in the cells which were treated by Bailong, the mRNA and protein level of p16INK4a decreased. It was shown that the inhibited proliferation of BGC82-3 cell by Bailong may come from the enhanced p16INK4a gene expression in G1 phase. Being same as p16INK4a, tumor suppressor genes Rb, p21 and oncogene c-myc expression were all affected by Bailong. When PKA inhibitor was added, the results were reversed.
Conclusion: Bailong can affect many anticancer genes (including p16INK4a, p21 and Rb genes) and oncogenes (including c-myc) transcription by regulating cAMP-PKA pathway.