RESUMO
Objective: To investigate all trans retinoid Acid (ATRA) inhibition of cell growth in human retinoblastoma Y79 cells, and its mechanism. Methods: Antiproliferation effects of ATRA on Y79 cells were determined by 3 H thymidine incorporation. Cell cycle analysis was performed by flow cytometry. JNK phosphorylation was analyzed by Western blot analysis. Results: After 36 h treatment with 10 -6 mol?L -1 ATRA, 3 H thymidine incorporation decreased to 40%, under the same condition, Y79 cells were arrested in G 0 /G 1 and Sub G 1 peak appeared. Curcumin, JNK blocker, blocked the growth inhibition by ATRA. JNK was phosphorylated in 10 to 20 min. Conclusion: JNK phosphorylating mediated ATRA inhibition of apoptosis in Y79 cells. These results suggested that ATRA might have clinical application for treatment of retinoblastoma.
RESUMO
Objective: To investigate the effect of all trans retinoid acid (ATRA) on bone cell proliferation and differentiation. Methods: Newborn rat calvarial osteoblastic cells were isolated and the metabolism of the osteoblastic cells were determined by MTT, Goldens method and immunocytohistologic method. Results: 10 -5 , 10 -6 , 10 -7 , 10 -8 , 10 -9 mol/L ATRA could increase osteoblastic cells proliferation after 72 h culture; 10 -5 , 10 -6 , 10 -7 mol/L ATRA could increase ALP activity. The expression of cyclin D 1 was decreased. Conclusion: ATRA stimulates the proliferation and differentiation of rat calvarial osteoblastic cells in vitro. Cell cycle relative proteins may play an important role in control of cell proliferation and differentiation induced by retinoic acid and derivatives.