The Expression Of ROCK Protein And Its Effect On The Metastatic And Invasive Ability Of Y79Retinoblastoma Cells

Background: Retinoblastoma (RB) is the most common intraocular tumor inchildhood worldwide. It is a deadly pediatric eye cancer. The main cause of death inRB patients is intracranial and systemic metastasis. ROCK is the main downstreameffector of Ras-homologous (Rho) family of GTPases which are involved in manycellular functions, such as cell proliferation, invasion and metastasis. Overexpressionof ROCK promotes invasion and metastasis in many solid tumors. However, the effectof ROCK in RB is largely unknown.Methods: ROCK1and ROCK2mRNA expression in Y79cell lines wereexamined by RT-PCR. Protein expression in Y79cell line were examined by westernblot analyses. ROCK-1and ROCK-2siRNA were transfected into Y79cells withLipofectamine2000. Cell proliferation was evaluated by CCK-8assay after exposureto ROCK inhibitor (Y-27632). We examined the effect of ROCK inhibitor (Y-27632,ROCK-1and ROCK-2siRNA) on Y79cell adhesive capacity by cell adhesion assay.Cell invasion assay through matrigel was used to study the effect of ROCK inhibitoron Y79cell invasive capacity.Results: The expression of mRNA of ROCK-1was more than that of ROCK-2inY79cell lines. The protein expression levels of ROCK-1and ROCK-2were reducedin the cells transfected with siRNA. Y-27632treatment didn’t show any changes ofY79cells proliferation. Adhesive ability of Y79cells was increased in Y79cellstreated with Y-27632or transfected with ROCK-1siRNA. The invasive capacity ofY79cells showed an inverse relationship with increasing Y-27632concentration. Invasion ability of Y79cells was decreased in Y79cells transfected with ROCK-1siRNA. However, there was no change of adhesive ability or invasive capacity in Y79cells transfected with siRNA against ROCK-2.Conclusions: The findings of this study demonstrate that ROCK-1protein plays akey role in regulating metastasis and invasion of Y79cells, suggesting that theROCK-1dependent pathway may be used as a potential target for therapy of RB.