维A酸抑制人类舌鳞癌Tca8113细胞增殖及诱导凋亡的受体机制研究

目的研究维A酸抑制人类舌鳞癌Tca8113细胞株的增殖和诱导凋亡的受体机制。方法用MTT法和细胞周期分析法研究3种维A酸（9-cis—RA、at—RA和13-cis—RA）、TTNPB（RAR激动剂）和甲氧普烯酸（Ma，RXR激动剂）对Tca8113细胞增殖的影响。通过Bax／Bcl．2免疫细胞化学染色、TUNEL法及活性caspase-3检测，研究维A酸诱导Tca8113细胞凋亡的作用。结果维A酸和TTNPB对Tca8113细胞均有不同程度的抑制增殖作用，其中TTNPB的抑制作用最强，而Ma无此作用。细胞周期分析结果显示，维A酸和TTNPB均可增加G1／G0期细胞百分比，其中以TTNPB的作用最强，而Ma无此作用。维A酸和TTNPB均可上调Bax表达并下调Bcl-2表达，TUNEL检测显示．维A酸和TTNPB均可诱导Tca8113细胞凋亡，同对照相比均有显著性差异（P〈0．05），而Ma与对照组相比，无显著性差异（P〉0．05）。活性caspase-3分析显示，除了Ma外，所有试剂均不同程度地上调caspase-3的表达，以TTNPB的作用最强（P〈0．05）。结论维A酸能够抑制Tca8113细胞的增殖，并诱导凋广-RXR的活化与这些作用无关，而RAR的活化则与这些作用可能有关。此外，维A酸诱导Tca8113细胞凋广涉及到caspase-3途径。

Receptor-related mechanism of proliferation inhibilion and apoptosis induetion of human tongue squamous cell line Tca8113 by retinoids

OBJECTIVE: To investigate the receptor-related mechanism of retinoids inhibiting proliferation and inducing apoptosis of human oral squamous cell carcinoma cell line Tca8113. METHODS: The effects of 3 retinoids (namely 9-cis-RA, at-RA and 13-cis-RA), TTNPB (RAR agonist) and methoprene acid (Ma, RXR agonist) on proliferation and cell cycle of Tca8113 cells were analyzed by MTT assay and flow cytometry. The roles of these agents in inducing apoptosis of Tca8113 cells were also evaluated by detecting the expression of Bcl-2/Bax, TUNEL and active caspase-3 analysis. RESULTS: Both retinoids and TTNPB could inhibit the proliferation of Tca8113 cells, and the effect of TTNPB was the most powerful in all the reagents, but MA had no such effect. At the concentration of 1 x 10(-5) mol/L, all the agents except for Ma could increase the percentage of G(1)/G(0)-stage cells after incubation of the cells for 24 h and 48 h. Retinoids and TTNPB could up-regulate the expression of Bax and down-regulate Bcl-2 expression. The results of TUNEL demonstrated that retinoids and TTNPB, but not Ma, could induce apoptosis of Tca8113 cells as compared with the control group (P<0.05). Except for Ma, all the agents up-regulated caspase-3 expression, and the effect of TTNPB was the strongest (P<0.05). CONCLUSIONS: Retinoids can suppress the proliferation of and induce apoptosis of Tca8113 cells, the effect of which involves activation of RAR but not RXR. caspase-3 pathway is involved in apoptosis-inducing effects of retinoids.