Introduction: The outcomes following radical treatment for bladder cancer (BC) remain poor, with 5 year overall survival (OS) rates of approximately 50% and over 5000 deaths per year in the U.K. There has been paucity of significant therapeutic developments since the introduction of cisplatinum based chemotherapy in the 1970's. The aim of this study was to identify putative drug targets for the treatment of this aggressive form of cancer.Methods: A tissue microarray (TMA) was constructed from the cystectomy specimens of 497 BC patients and 70 controls, linked to a clinical database with extended follow up. The online database Oncomine® was interrogated to identify putative treatment targets which were subsequently evaluated using in-vitro models of high grade invasive bladder cancer (using the J82 and T24 cell lines). In-vitro modelling was conducted using siRNA target knockdown during proliferation, chemo-sensitivity, migration and Matrigel invasion assays. Expression of the putative targets was then correlated with tumour characteristics and patient outcomes, by IHC and automated image analysis of the TMA.Results: The proteins CYR61 and CTGF were selected from Oncomine® and studied in conjunction with the HGF/MET axis, on the basis of known interactions in other cancer types. siRNA knockdown of both proteins abrogated HGF induced Matrigel invasion in both cell lines. CYR61 knockdown significantly reduced HGF induced cell migration and foetal calf serum (FCS) induced Matrigel invasion in both cell lines. Knockdown of both proteins also significantly increased the sensitivity of both cell lines to cisplatinum.CYR61 expression was significantly increased in BC samples compared to normal controls and an independent predictor of OS at 6 years (HR 1.493, p=0.030). In contrast, loss of CTGF expression was significantly associated with increasing tumour stage and worse OS. MET expression was reduced in BC compared to controls and not predictive of survival following cystectomy.Conclusions: The in-vitro findings for CTGF as a treatment target were encouraging, although these findings were not supported by the TMA data.CYR61 promotes an aggressive bladder cancer phenotype and knockdown reverses features of EMT and increases chemo-sensitivity. Clinical cohort correlation confirms CYR61 to be a promising treatment target in bladder cancer.
|Date of Award||1 Aug 2015|
- The University of Manchester
|Supervisor||Michael Brown (Supervisor) & Noel Clarke (Supervisor)|