Antimicrobial peptide LL-37 promotes YB-1 expression, and the viability, migration and invasion of malignant melanoma cells

The cathelicidin antimicrobial peptide, LL-37, is a multifunctional peptide with a broad spectrum of antimicrobial activities, such as chemotaxis and neutralizing endotoxins. Previous studies have demonstrated that it LL-37 serves a functional role in the development of numerous types of cancer including ovarian, breast, prostate and lung cancer. However, its role in the development of malignant melanoma (MM) remains unclear. To determine the role of LL-37 and the potential interaction with Y-box binding protein 1 (YB-1) in MM, RNA interference, western blot, reverse transcription-quantitative polymerase chain reaction, MTT and Transwell assays were performed. The current study demonstrated that LL-37 induced YB-1 expression, and increased tumor cell proliferation, migration and invasion of A375 and A875 MM cell lines. In addition, inhibition of nuclear factor-κB (NF-κB) attenuated LL-37-induced YB-1 expression. These results demonstrate that, through the upregulation of YB-1 expression and the activation of the NF-κB signaling pathway, LL-37 may promote the malignant progression of MM cells in vitro.