Synergism between heparin and adriamycin on cell proliferation and apoptosis in human nasopharyngeal carcinoma CNE2 cells.

AIM: To measure the effect of addition of heparin to adriamycin (ADM) on cell proliferation and apoptosis in CNE2 cells and investigate the possible molecular mechanisms of heparin and ADM interactions. METHODS: Cell viability and cell cycle were determined by MTT assay and flow cytometry. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and agarose gel electrophoresis. The expression of Bax, Bcl-2, p53, and p21 was examined by Western blot. RESULTS: ADM (5 mg/L) alone inhibited the growth of CNE2 cells, which was magnified when heparin was added. ADM elicited typical apoptotic morphologic changes. Compared with ADM or heparin alone, ADM plus heparin obviously enhanced the number of TUNEL positive cells from 12.6 % 1.1 % to 65.7 % 1.3 %, and the DNA ladder was more clearly observed. After exposure to different concentrations of heparin (with or without ADM) for 24 h, CNE2 cells were accumulated in G0/G1 phase. There was a decrease in the number of cells in S phase by the combined heparin and ADM treatment compared to heparin or ADM alone. The ratio of Bax/Bcl-2 was elevated, and p53 and p21 mRNA were over-expression. CONCLUSION: Heparin and ADM appear to interact in a synergistic manner, which may be related to the over-expression of p53 and p21 mRNA and the elevated ratio of Bax/Bcl-2 mRNA.