Lysyl oxidase-like 3 (LOXL3) is an extracellular
enzyme involved in the synthesis of
collagen and
elastin, and it has been reported to promote
melanoma cell proliferation and invasion in vitro. However, the expression level of LOXL3 at different stages of melanocytic lesions and the role of LOXL3 in
melanoma pathogenesis remain unknown. Immunohistochemical staining of LOXL3 in a tissue microarray of 373 biopsies at different melanocytic stages was conducted. The correlation between LOXL3 expression and patient survival was examined using Kaplan-Meier survival analysis. Univariate and multivariate Cox regression analyses were conducted to study the hazard ratios. The tissue microarray study revealed that stronger expression of LOXL3
protein was found at more advanced melanocytic stages (P < 0.0001; χ2 test). Increased LOXL3 expression was associated with enhanced
tumor thickness and mitosis. Survival analysis showed significantly worsened prognosis in primary
melanoma patients when the LOXL3 expression level was higher (P = 0.043; log-rank test). Multivariate Cox regression analysis further showed that LOXL3 expression is a prognostic factor for primary
melanoma patient survival (P = 0.04). LOXL3 expression is positively correlated with
tumor progression and invasion, and its overexpression is associated with worse prognosis of primary
melanoma patients. LOXL3 can serve as a prognostic marker to help identify primary
melanoma patients at higher risks of death.