Glyoxalase I Is Differentially Expressed in Cutaneous Neoplasms and Contributes to the Progression of Squamous Cell Carcinoma

Glyoxalase I (GLO1) is a methylglyoxal detoxification enzyme being implicated in the progression of multiple malignancies. However, currently, the role of GLO1 in human nonmelanoma skin tumors remains unclear. To explore the expression of GLO1 in cutaneous neoplasms and its role in the pathogenesis of skin cancers, we determined the GLO1 expression in multiple subtypes of cutaneous neoplasms and cell lines harboring different tumorigenicity. Also, the GLO1 siRNA transfection was performed in squamous cell carcinoma (SCC)-13 cells or SCC in the xenograft model. The results show that GLO1 was overexpressed by SCC, basal cell carcinoma, and verrucous carcinoma but weakly expressed by several benign neoplasms. Human papilloma virus 16 E6/E7-transfected keratinocytes expressed more GLO1 than did normal keratinocytes, although both of them had lower levels of GLO1 than SCC-13 cells. Moreover, the knockdown of GLO1 by siRNA was related to enhanced apoptosis of SCC-13 cells in the presence of tumor necrosis factor-related apoptosis-inducing ligand and inhibited cell invasion and migration, which was mirrored by the suppressed growth of SCC xenografts in mice. Finally, the GLO1 regulation of SCC-13 cells might be relevant to methylglyoxal-induced p53 translocation. Therefore, GLO1 is prevailingly expressed in cutaneous neoplasms of higher malignancy and contributes to the progression of SCC.