Is CRPC definition still valid in the new era of antiandrogens for mHSPC treatment?

Rho family GTPases act as molecular switches to regulate numerous cellular processes, including malignant transformation. Commonly, overexpression of Rho GTPases contributes to tumorigenesis. Elevated expression of several Rho GTPases has been reported in lung cancer and is associated with poor prognosis. The RHOV gene encodes the atypical Rho family GTPase Chp/RhoV, which is capable of transforming fibroblasts, although other functions of Chp remain largely elusive. RHOV is expressed in normal lung tissue in rats, but not in humans. RHOV expression was found in several human cancer cell lines, including non–small-cell lung cancer (NSCLC) cell line A549, but expression of RHOV in NSCLC tumors has never been investigated. Here we studied the expression of the RHOV gene in lung cancer cell lines and in 29 matched pairs of NSCLC tumors and adjacent nontumorous tissues. We found that RHOV is expressed in lung cancer cell lines and is upregulated in the majority of studied lung tumors. Analysis of the Oncomine database revealed correlation between elevated RHOV level and poor patient survival. We propose that the RHOV gene could be validated as a diagnostic or prognostic marker for NSCLC, and that observed overexpression of RHOV might contribute to tumorigenesis.