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Objective: To study the regulation of bailong, a Chinese herbal anticancer preparation and hexamethylene bisacetamide (HMBA) on cyclin dependent kinase inhibitor P16 (CKI-P16) genes in human cancer cells., Methods: The expression of CKI-P16 in different human cancer cells treated by Bailong or HMBA under different condition, was examined using Northern hybridization, Western blotting assay, etc., Results: After being treated by Bailong or HMBA, the P16 expression increased. This effect was closely related to co-regulation of cAMP-PKA and DAC-PKC signal pathway. When PKA pathway was blocked with PKA inhibitor, the P16 expression decreased, while PKC pathway was blocked, it enhanced., Conclusion: (1) The low P16 expression in G1 phase of cancer cell, as compared with that in S, G2 and M phases, might be an important factor responsible to the incompetence of P16 in inhibiting effectively the malignant change of cancer cell. (2) Mechanism of Bailong and HMBA on cancer cell proliferation inhibition might be correlated with the enhancement of P16 expression in G1 phase of cancer cells. (3) Regulation and expression of Bailong and HMBA on P16 showed the common character of Chinese and western medicine in regulating cancer cells. (4) This study elucidated that upstream of P16 was related to cAMP/PKC signal pathway closely.

Objective: To investigate and compare the common effect of Bailong, a Chinese herbal preparation, and Hexamethylene bisacetamide (HMBA), a western cell differentiation inducer, on growth regulation and phenotype of human gastric cancer (MGC80-3) cells in different phases of cell cycle., Methods: Synchronized MGC80-3 cells in monolayer cultures with nitrous oxide under high pressure were double blocked with overdosage of TdR in the 4 cellular phases (G1, S, G2 and M), and then collected and treated with Bailong and 5 mmol/L HMBA respectively., Results: Both medicines could suppress the cell proliferation, soft agar cloning growth and microfilament assembling of different phases of cells, the effect on cells of G1 phase was the most significant one., Conclusion: Bailong and HMBA had significant common characteristics in inducing cell differentiation of MGC80-3 cells in different phases of cell cycle.

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.

Objective: To evaluate the effects of traditional Chinese medicine formulae (Bailong) on cAMP/PKA and diacylaglycerol (DAG) protein kinase (PKC) pathways of the MGc80-3 cells., Methods: cAMP level, DAG content and activities of PKA and PKC were measured in different groups: (1) control, (2) 1.8 mg/ml Bailong, (3) 1.8 mg/ml Bailong +20 ug/ml PKA inhibitor, (4) 5 mumol/L PKC inhibitor., Results: When MGc80-3 cells were in treatment with Bailong for 3 hours, cAMP level and PKA activity were 11.27%, and 19.7% higher than that of the control, while DAG content and PKC activity were 47.0% and 64.2% lower than that of the control; When PKC pathway was blocked by PKC inhibitor GF-109203X, cAMP level and PKA activity were increased by 78.8% and 33.5% as against that of the control, while the DAG content and PKC activity were decreased by 40. 3% and 56.3% respectively. When MGc80-3cells were treated with Bailong, and at the same time, blocked PKA pathways by PKA inhibitor, cAMP level and PKA activity were decreased by 46.0% and 28.9%, on the other hand, DAG content and PKC activity were increased by 50.7% and 51.6% as against that of the Bailong group., Conclusions: (1) There was relationship of causes and result between differentiation of MGc80-3 cells and the signal pathways. (2) Results of this study were similar to that of hexamethylenebisacetamide (HMBA). It is shown that the two signal systems are the foundation of regulative effects of Chinese medicine formulae Bailong or HMBA on proliferation and differentiation in MGc80-3 cells.