Factor VIII a coagulation co-factor is a relevant survival factor in bladder cancer cell lines.

Abstract

Background: Factor VIII (FVIII), an essential coagulation co-factor and independent cancer associated thrombotic risk factor, has recently been shown to be synthesized directly by a broad profile of cancers. With evident extra-coagulative functions, it remains to understand if FVIII can play a functional role in cancer.

Objectives: Establish if FVIII plays a direct role in bladder cancer cell models.

Methods: Bladder cancer cell lines 5637 and ECV-304 were treated with recombinant human FVIII B-domain deleted (rFVIII-BDD) or full-length (rFVIII-FL) in low serum conditions, where cell cycle, migration, and cell survival were assessed. Cell cycle by 7-Aminoactinomycin D (7-AAD) incorporation, and migration by Transwell or wound healing assays. Cell survival by crystal violet (CV;OD592) and 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT;OD570) assays. Cell adhesion with integrin β1 (Intβ1) and αV (IntαV) protein levels, Annexin-V-FITC/7-AAD staining and Bcl2 with procaspase3 levels, for apoptosis. Cancer cell-derived effects were assessed by silencing FVIII using short hairpin RNA (shFVIII).

Results and conclusions: In both bladder cancer cell lines cell cycle progression was pushed, and migration advanced by rFVIII. More dramatic were the survival effects for rFVIII-FL, confirmed in a cell line of diverse origin, the osteosarcoma U2OS, through the maintenance of cell adhesion and inhibition of apoptosis. Further, silencing cell-derived FVIII retarded both cell cycle progression and migration. More importantly, cell survival was dramatically reduced and could be blocked by the administration of rFVIII-FL. Overall, this investigation highlights FVIII as a relevant survival factor in bladder cancer cells and provides evidence of a role in cancer.