Role of LONP2 in head and neck squamous cell carcinoma

Lon Peptidase 2, Peroxisomal (LONP2) is a peptidase in peroxisomes that selectively degrades oxidatively damaged proteins in cells and is upregulated in several cancers. In this study, we found both the mRNA and protein level of LONP2 was upregulated in head and neck squamous cell carcinoma (HNSCC) samples. Ectopic overexpressed LONP2 enhanced HNSCC cell growth and migration. Nevertheless, LONP2 silencing suppressed tumor growth in vitro and in vivo. It was also indicated that knockdown of LONP2 also impaired the cell cycle progression and improved apoptosis rate of HNSCC cells. The results of RNA sequencing showed that plastin 3 (PLS3) was heavily downregulated after LONP2 silencing. PLS3 is an actin-bundling protein that functions as an oncogene in several cancers. Furthermore, knockdown of PLS3 inhibited the cell proliferation induced by LONP2 overexpression. In conclusion, we identified an oncogenic effect of LONP2 on cell proliferation and migration in HNSCC via positively regulating the expression of PLS3.