Abstract: 【Abstract】 Objective To investigate effects of the ROCK1 gene on proliferation and migration of and related molecular expression in keloid fibroblasts. Methods Immunohistochemical technique was used to detect ROCK1 protein expression in human keloids and normal skin tissues, and Western blot analysis was performed to detect the expression of ROCK1, transforming growth factor β1 （TGF-β1） and E-cadherin in keloid tissues. In vitro cultured human keloid fibroblasts （HKFs） were divided into 4 groups: ROCK1 gene overexpression control group （ROCK1 NC group） transfected with ROCK1 gene overexpression control vectors, ROCK1 gene overexpression group （ROCK1 OE group） transfected with ROCK1 gene overexpression vectors, ROCK1 gene knockdown control group （sh NC group） transfected with ROCK1 gene knockdown control vectors, and ROCK1 gene knockdown group （shROCK1 group） transfected with ROCK1 gene knockdown vectors. Cell counting kit-8 （CCK8） assay was performed to evaluate the effect of ROCK1 gene on the survival rate of HKFs, Transwell assay to evaluate the effect on the migration of HKFs, and real-time fluorescence-based quantitative PCR （qRT-PCR） and Western blot analysis were conducted to determine the mRNA and protein expression of ROCK1, TGF-β1 and E-cadherin, respectively. Results Immunohistochemical study showed that ROCK1 protein expression decreased significantly in the human keloid tissues compared with the normal tissues （t = 6.47, P = 0.003）; Western blot analysis showed that the expression levels of ROCK1 and E-cadherin significantly decreased （t = 14.02, 162.20, respectively, both P < 0.001）, while TGF-β1 expression significantly increased （t = 76.01, P < 0.001） in the keloid tissues compared with the expression levels of corresponding proteins in the normal tissues . CCK8 assay showed that the cell activity was significantly lower in the ROCK1 OE group than in the ROCK1 NC group after 24-hour transfection （t = 3.25, 3.78, P = 0.031, 0.019, respectively）, and significantly higher in the shROCK1 group than in the sh NC group （t = 3.12, 2.79, P = 0.036, 0.049, respectively）. Transwell assay showed that the number of migratory cells was significantly lower in the ROCK1 OE group than in the ROCK1 NC group （t = 5.17, P = 0.004）, and significantly higher in the shROCK1 group than in the sh NC group （t = 9.28, P < 0.001）. Compared with the ROCK1 NC group, the ROCK1 OE group showed significantly increased mRNA and protein expression levels of ROCK1 and E-cadherin （P < 0.05 or < 0.001）, but decreased mRNA and protein expression levels of TGF-β1 （both P < 0.001）; compared with the sh NC group, the shROCK1 group showed significantly decreased mRNA and protein expression levels of ROCK1 and E-cadherin （P < 0.05 or < 0.001）, but significantly increased mRNA and protein expression levels of TGF-β1 （P = 0.005 or < 0.001）. Conclusions The ROCK1 gene can inhibit the proliferation and migration of HKFs. Overexpression of the ROCK1 gene can down-regulate the TGF-β1 gene expression and up-regulate the E-cadherin gene expression in HKFs.

Key words: Keloid, Fibroblasts, Cell proliferation, Cell movement, Transforming growth factor beta, Cadherins, Gene, ROCK1