[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.
Niu
Xin-wu
XW
Department of Dermatology, Second Hospital of Xi'an Jiaotong University, Xi'an 71004, China. nxw192@sohu.com
Feng
Jie
J
Peng
Zhen-hui
ZH
Ma
Hui-qun
HQ
Liu
Chao
C
Yuan
Jing-yi
JY
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001565:Benzoates / Q000494:pharmacology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D045744:Cell Line, Tumor; D006801:Humans; D018168:Receptors, Retinoic Acid / Q000187:drug effects* / Q000378:metabolism; D012176:Retinoids / Q000494:pharmacology*; D014062:Tongue Neoplasms / Q000473:pathology*; D014212:Tretinoin / Q000494:pharmacology*
D000970:Antineoplastic Agents; D001565:Benzoates; D018168:Receptors, Retinoic Acid; D012176:Retinoids; D014212:Tretinoin; C038864:4-(2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl)benzoic acid