Construction and evaluation of an efficient C‐Jun siRNA to downregulate matrix metalloproteinase in human keratinocytes and fibroblasts under UV exposure

BACKGROUND: C‐Jun and EGFR have not been explored as targets via the mechanism of RNA silencing. Hence, this study designed an efficient C‐Jun‐h‐825 small interfering RNA (siRNA) and investigated its effect on matrix metalloproteinase (MMP) and collagen expression in human keratinocytes exposed to UV radiation. METHODS: Five C‐Jun siRNAs were designed and screened for their ability to downregulate C‐Jun expression in human fibroblasts. These constructs were used to study changes in skin cancer‐related protein expression. HaCaT cells were grouped into 5‐carboxyfluorescien (FAM‐labeled) C‐Jun‐h‐825 siRNA + 2 hr prior irradiation; mock transfected + 2 hr prior irradiation; normal control; irradiation only for 2 hr; and Blank. Twenty‐four hours posttransfection, mRNA and protein levels of MMP‐I, MMP‐III, collagen‐I and collagen‐III were determined using standard RT‐PCR and ELISA kits. RESULTS: FAM‐labeled C‐Jun siRNA showed 80%–90% transfection efficiency. There was a significant increase in MMP‐I and MMP‐III and decrease in Col‐I and III mRNA levels when the cells were exposed to UV irradiation without siRNA transfection compared to blank (p < .05). This effect was reversed upon transfection with C‐Jun‐h‐825 (p < .01). CONCLUSION: Thus, C‐Jun‐h‐825 siRNA might help restore skin collagen by decreasing MMP expression in cells exposed to UVA. Constructs and vectors designed herein have the potential to be translated into a treatment for photoaging induced skin cancer.