AB251. 15-oxospiramilactone inhibits human renal cell carcinoma cell tumorigenesis through inhibition of Wnt/β-catenin signaling

© Translational Andrology and Urology. All rights reserved. Transl Androl Urol, 2016;5(S1) tau.amegroups.com measured by MTT assay. Phase distribution of cell cycle was analyzed by flow cytometry. The expression of Ect2 in protein level were detected by western blotting. RhoA activity was measured by Rho activation assay kit. Results: Our results showed that annexin V promoted rat Leydig cell proliferation and cell cycle progression in a doseand time-dependent manner. Increased level of annexin V also enhanced Ect2 protein expression. However, siRNA knockdown of Ect2 attenuated annexin V-induced proliferation of rat Leydig cells. Taken together, these data suggest that increased level of annexin V induced rat Leydig cell proliferation and cell cycle progression via Ect2. Since RhoA activity was increased following Ect2 activation, we further investigated whether Ect2 was involved in annexin V-induced proliferation via the RhoA/ROCK pathway, and the results showed that annexin V increased RhoA activity too, and this effect was abolished by the knockdown of Ect2. Moreover, inhibition of the RhoA/ROCK pathway by a ROCK inhibitor, Y27632, also attenuated annexin V-induced proliferation and cell cycle progression. Conclusions: We thus conclude that Ect2 is involved in annexin V-induced rat Leydig cell proliferation through the RhoA/ROCK pathway.