Fgf/Ptx3 Crosstalk In Bladder Cancer: Novel Prognostic And Therapeutic Implications

Bladder cancer is one of the most common cancers in the world. Although most of urothelial carcinomas (UCs) are low-grade papillary tumors, their propensity to recur and to progress to become invasive with a poor survival rate represents a major challenge. Different members of the Fibroblast growth factor (FGF) family are expressed by human bladder cancer cells, and aberrant expression of FGF receptors (FGFRs) is a typical feature of bladder cancer compared to normal urothelium. High expression levels of FGFR1 are associated with poor survival and FGFR3 is frequently dysregulated in UC. Thus, the FGF/FGFR system may represent a promising therapeutic target in invasive and noninvasive bladder cancer. Long-pentraxin 3 (PTX3) acts as a natural FGF trap by binding FGFs and hampering their biologic activity in various tumor models. Preliminary observations have shown that low-grade UCs express PTX3 while high-grade/invasive UCs lose PTX3 expression. Accordingly, bladder cancer cell lines share an overall presence of FGFRs and FGFs but express different levels of PTX3 in vitro and in vivo. Of note, high-grade/invasive cells express very low or undetectable levels of PTX3, whereas low-grade, papilloma-like cells express high levels of PTX3. Indeed, invasive bladder cancer cell xenografts grow faster in nude mice and express much lower levels of PTX3 than low grade-derived lesions, thus confirming an inverse correlation between UC grade and PTX3 expression. This hypothesis is reinforced by a preliminary case study performed on a small cohort of biopsies from UC patients confirming that the presence of PTX3 is a common feature of low-grade samples while PTX3 is poorly expressed or absent in aggressive/invasive cases. These data point to PTX3 as a natural FGF trap that could play a role in modulating bladder cancer progression and invasiveness and indicate that inhibition of the FGF/FGFR system by natural and synthetic FGF traps may represent a promising target for the therapy of UCs. Citation Format: Sara Matarazzo, Federica Maccarinelli, Gaia Cristina Ghedini, Laura Melocchi, Mattia Bugatti, William Vermi, Marco Presta, Roberto Ronca. FGF/PTX3 crosstalk in bladder cancer: novel prognostic and therapeutic implications [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A039.