Effects of histamine on growth and apoptosis of human melanoma cells A375

Objective: To investigate the effects of histamine on growth and apoptosis of human melanoma cells A375. Methods: The effect of histamine on growth of A375 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis by double staining with Annexin V-FITC and PI, and active caspase-3 analysis by staining FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. StreptAvidin-Biotin Complex (SABC) immunocytochemical assays were adopted to detect Bax/Bcl-2 protein expressions.Results: Histamine inhibited proliferation of A375 cells in a dose- and time-dependent manner, and altered cell cycle distribution of A375 cells revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. Histamine induced apoptosis of A375 cells (P<0.05), elevated the cells population with detectable active caspase-3 (P<0.05), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (P<0.05). Conclusion: That histamine inhibits cell cycle progress of A375 cells is one of the possible mechanisms of proliferation arrest of A375 cells elicited by histamine. Histamine mediates apoptosis in A375 cells that may be caspase-dependent through mitochondria routine. Histamine with high concentration inhibits growth of A375 cells in vitro by interfering proliferation and inducing apoptosis of cells.

Celecoxib in combination with retinoid CD437 inhibits melanoma A375 cell in vitro

This study aimed to investigate the effects of celecoxib,synthetic retinoid 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalenecarboxylicacid(CD437)and the combination of the two on cell proliferation,apoptosis,and cycle arrest of human malignant mela-noma A375 cells.3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazoliumbromide assay(MTT assay)was applied to determine the anti-proliferative effects of the drugs on human malignant melanoma A375 cells.Flow cytometry was performed to investigate the influence of the drugs on cell cycle and cell apoptosis.Both celecoxib and CD437 could inhibit the growth of human malignant melanoma A375 cells in a dose-dependent manner.Celecoxib at 80μmol/L inhibited proliferation,induced apoptosis and G2/M cell cycle arrest of human malignant melanoma A375 cells after treatment for 24 h[proliferation inhibiting rate:(50.2±2.51)%,apoptosis rate:(35.91±1.80)%].CD437 at 10μmol/L inhibited proliferation,induced apoptosis and G0/G1 cell cycle arrest of human malignant melanoma A375 cells after treatment for 24 h[proliferation inhibiting rate:(58.6±2.38)%,apoptosis rate:(28.03±0.77)%].Celecoxib in combination with CD437 could significantly enhance the effects of inhibiting proliferation and inducing apoptosis of human malignant melanoma A375 cells 24 h after treatment compared with the drug alone[proliferation inhibiting rate:(68.92±1.72)%,apop-tosis rate:(42.09±1.05)%,both P<0.05]and decrease the proportion of the S phase in the cell cycle.Celecoxib could inhibit the growth of human malignant melanoma A375 cells by inducing apoptosis and G2/M cycle arrest.CD437 could inhibit the growth of human malignant melanoma A375 cells by inducing apoptosis and G0/G1 cycle arrest.Celecoxib exhibited additive effects with CD437 on retarding the growth and inducing apoptosis of human malignant melanoma A375 cells.Celecoxib in combination with CD437 may become an effective method for prevention and treatment of human melanoma.