Uncovering the role of nuclear Lysyl oxidase (LOX) in advanced high grade serous ovarian cancer

Objective Lysyl oxidase (LOX) is an enzyme that catalyzes the cross-linking of collagen and elastin in the extracellular matrix, thus controlling the tensile strength of tissues. Along with this primary function, there are evidences supporting a role for LOX in many critical biological functions, including gene expression regulation, cell growth, adhesion and migration. Accordingly, recent studies have supported a pivotal role for LOX in cancer progression and metastasis. The current study aimed at investigating the prognostic significance and the functional role of intracellular LOX in ovarian cancer. Methods To this end, we analyzed LOX expression by immunohistochemistry in archived tumor material from advanced high grade serous ovarian cancer (HGSOC) patients (n = 70) and correlated data with clinicopathological parameters and with response to chemotherapy. In vitro experiments were also used to investigate the functional consequences of LOX expression on behavioral aspects of HGSOC cells. Results Our results showed that nuclear LOX expression is associated with unfavorable outcome in advanced HGSOC, being an independent prognostic factor for disease recurrence. Besides, high nuclear levels were seen to be associated with resistance to first-line chemotherapy. Through gene expression modulation experiments in HGSOC cell lines, we demonstrate that LOX positively regulates cell proliferation, migration and anchorage-independent growth. Conclusions Collectively, our data suggest that LOX functions as a tumor promoter in HGSOC and positively regulates several aspects of the metastatic cascade.