LOXL1 modulates the malignant progression of colorectal cancer by inhibiting the transcriptional activity of YAP
Abstract Background LOX-like 1 (LOXL1), as a lysyl oxidase, emerging evidences revealed the effect in cancer malignant progression. However, its role in colorectal cancer (CRC) and the underlying molecular mechanisms have not yet been elucidated. Methods LOXL1 expression in colorectal cancer was detected by immunohistochemistry, western blot and real-time PCR. In vitro , colony formation assay, wound healing assay, migration and invasion experiment were performed to investigate the effects of LOXL1 in cell proliferation, migration and invasion, respectively. In vivo , metastasis models and mouse xenograft were used to determine tumorigenicity and metastasis ability. Molecular biology experiments were utilized to reveal the underlying mechanisms of LOXL1 modulating Hippo pathway. Results LOXL1 is highly expressed in normal colon tissues compared with cancer tissues. In vitro, Silencing LOXL1 in CRC cell lines dramatically enhanced migration, invasion, and colony formation, while overexpression of LOXL1 manifested the opposite effects. Results of the in vivo experiments demonstrated that the enforced expression of LOXL1 in CRC cell lines had drastically inhibited the progression of metastasis and tumour growth. Mechanistically, LOXL1 inhibited the transcriptional activity of Yes-associated protein (YAP) was through interaction with MST1/2 and increasing the phosphorylation of MST1/2. Conclusions LOXL1 may function as an important tumour suppressor in regulating tumour growth, invasion and metastasis via negative regulating of YAP activity.