Abstract
Disease progression after curative surgery is still the main challenge for colorectal cancer (CRC). Identifying biomarkers and precise mechanisms in CRC disease progression is necessary for therapeutic improvement. As a transcription factor, ZEB1 promotes malignancy, but the precise mechanism by which ZEB1-dependent transcriptional regulation remains largely undefined. In this study, the transcriptional regulation of lysyl oxidase-like 2 (LOXL2) by ZEB1 in CRC was investigated. Our data show that ZEB1 enhanced LOXL2 transcription through direct binding to its promoter. The gain of function assays of ZEB1 showed increased cell proliferation, migration, and invasion. The inhibition of LOXL2 impaired the invasion and migratory ability of CRC cells, but had no effect on cell proliferation in vitro and in vivo. Immunohistochemical staining of tumor tissues indicated that elevated ZEB1/LOXL2 expression was significantly associated with lymph node metastasis and TNM stage. More importantly, elevated ZEB1/LOXL2 expression was an independent prognostic factor in CRC patients. These findings provide a molecular basis for the promotion of an invasive cancer phenotype by ZEB1-LOXL2 overexpression. Our results identify ZEB1/LOXL2 as a prognostic biomarker and potential therapeutic target against progression of CRC.