DUSP22 promotes senescence of HS-1 skin cancer cells through triggering MAPK signaling pathway.

OBJECTIVE: Skin cancer severely threatens the public health. Dual-specificity protein phosphatase 22 (DUSP22) characterizes with multiple roles regulating cell growth, proliferation and gaining. This study aims to investigate the regulatory role of DUSP22 on aging of skin cancer cells and clarify molecular mechanisms, along with potential application value.

PATIENTS AND METHODS: HS-1 skin cancer cells were transfected with DUSP22 by liposome transfection approach. Western blot assay was used to evaluate the effects of DUSP22 on aging protein of HS-1 cells, and activation of mitogen-activated protein kinase cascade (MAPK) signal pathway. Real-time PCR (RT-PCR) and Western blot assay were used to examine the DUSP22 expression in HS-1 cancer cells. Meanwhile, the correlation between P53 protein and aging was also investigated.

RESULTS: Transfection of DUSP22 plasmid significantly elevated DUSP22 expression in HS-1 skin cancer cells compared to un-transfected cells (p<0.05), and activated MAPK to induce cell aging. Transfection of small interfere RNA (siRNA) DUSP22 significantly suppressed DUSP22 expression in HS-1 cancer cells, inhibited MAPK signal pathway, and decreased aging proteins P53 and P21 compared to the untreated group (p<0.05). DUSP22 was downregulated in HS-1 skin cancer cells, with MAPK signal pathway inhibition, and lower aging protein P53 expression. DUSP22 expression was positively correlated with aging protein P53 (p<0.05).

CONCLUSIONS: DUSP22 facilitated HS-1 skin cancer cell aging via activating MAPK signal pathway, possibly providing novel strategy against skin cancer.