Abstract 764: LOX and LOXL2 inhibition as a treatment for ovarian cancer

Abstract

Abstract Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy in women. Despite advances in our understanding of the molecular biology of EOC, patient survival has not significantly improved in decades and new treatments are needed. There is increased interest in therapeutic targeting of the tumor microenvironment (TME). The lysyl oxidase (LOX) family of enzymes are involved in extracellular matrix remodelling through crosslinking of collagen and elastin. They have been shown to play an important role in the TME of other cancers and are regulated by hypoxia, however little is known about their role in EOC. Therefore we aimed to investigate the role of LOX and LOXL2 in EOC using in vitro models. Tumor epithelial (n = 2) and matched cancer-associated fibroblast cell lines (n = 2) derived from an SV40-induced mouse model of EOC were generated. MTT assays were performed on all cell lines to assess the effect of LOX and LOXL2 inhibition on cell viability. The effect of LOX and LOXL2 inhibition on cancer cell migration and invasion towards cancer-associated fibroblast conditioned media was also investigated using transwell assays. RNA and protein were isolated and analysed from cells cultured in normoxic and hypoxic conditions to assess whether LOX and LOXL2 gene and protein expression is regulated by hypoxia. Inhibition of LOX and LOXL2 did not affect cell viability. LOX and LOXL2 inhibition significantly reduced the migration and invasion of EOC cells towards cancer-associated fibroblast conditioned media in vitro (p<0.05). Gene expression analysis comparing Lox and Loxl2 expression in all cell lines demonstrated a significant increase in Lox and Loxl2 expression in cells cultured in hypoxia (p<0.05). Similarly, cellular and secreted LOX and LOXL2 protein expression was increased in cells cultured in hypoxic conditions, supporting hypoxia as a regulator of LOX and LOXL2 expression. This study demonstrates a role for LOX and LOXL2 in promoting migration and invasion of EOC cells in vitro. The upregulation of LOX and LOXL2 in hypoxia suggests a role in facilitating tumor growth and progression within hypoxic tumors. These results provide support for the utility of LOX and LOXL2 inhibition as promising and novel therapeutic strategies in EOC. Citation Format: Angela Cho, Amanda L. Hudson, Samuel Yuen, Nham Tran, Viive M. Howell, Emily K. Colvin. LOX and LOXL2 inhibition as a treatment for ovarian cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 764.