RhoB enhances migration and MMP1 expression of prostate cancer DU145
EXPERIMENTAL AND MOLECULAR PATHOLOGY
Authors: Yoneda, Misao; Hirokawa, Yoshifumi S.; Ohashi, Atsuyuki; Uchida, Katsunori; Kami, Daisuke; Watanabe, Masatoshi; Yokoi, Toyoharu; Shiraishi, Taizo; Wakusawa, Shinya
Abstract
Rho family protein regulates variety of cellular functions as cytoskeletal organization, cell proliferation and apoptosis. in the present study, we demonstrate that RhoB-overexpressed prostate cancer cells showed an enhanced cell motility and the administration of the GSK-3 inhibitors inhibited this increase in migration. Among the extracellular matrix and adhesion-related molecules, MMP1 RNA expression was increased in RhoB-overexpressed cells, administration of MMP inhibitor suppressed the collagen gel invasion in these cells. This is the first report evaluating RhoB function and the downstream signaling events in prostate cancer cell. Our results indicate that RhoB promotes cell motility and invasion in a metastatic prostate cancer cell. (C) 2009 Elsevier Inc. All rights reserved.
Rho GTPases Control Ciliary Epithelium Cells Proliferation and Progenitor Profile Induction In Vivo
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
Authors: Del Debbio, Carolina Beltrame; Santos, Marinilce Fagundes; Irene Yan, Chao Yun; Ahmad, Iqbal; Hamassaki, Dania Emi
Abstract
PURPOSE. Rho GTPases play a central role in actin-based cytoskeleton reorganization and regulate multiple signaling pathways that control gene transcription, cell survival, and proliferation. We investigated the effect of Rho GTPases on cell cycle regulation and progenitor genes expression on mouse ciliary epithelium (CE), a potential source of progenitor/stem cells in the adult retina. METHODS. Rho GTPases were activated by intraocular injection of lysophosphatidic acid and inactivated by Clostridium difficile Toxin A (general Rho GTPase inhibitor), NSC23766 (Rac1 activation inhibitor), or Y27632 (Rho-associated protein kinase [ROCK] inhibitor). Thereafter, we assayed for RhoA, RhoB, and Rac1 protein localization in CE cells. Proliferation was examined by the expression levels of cell cycle regulators p27(kip), p16(INK4a), and Ki67 and the effects on progenitors by determining the changes in Pax6 and Chx10 progenitor markers expression. RESULTS. All GTPases investigated were expressed in mouse CE cells. Activation increased the coexpression of Pax6 and Chx10, but had no significant effect on the proliferation of CE cells. In contrast, Rho GTPases inactivation increased cell proliferation and potentiated the proliferative effect of growth factors. Specific inactivation of Rac1 or ROCK increased the levels of Ki67 and decreased the expression of the cell cycle inhibitors p27(kip) and p16(INK4a). CONCLUSIONS. This study reports that Rho GTPase modulation (activation and inactivation) controls the expression of retinal progenitor genes and proliferation, respectively, in the adult ciliary epithelial progenitor/stem cells of rodent eyes. The modulation of these two different mechanisms (proliferation and reprogramming) may provide a potential new approach in retinal repair.