Objective  The effect of Smad7 on epithelial-Mesenchymal Transition (EMT) of keloid keratinocytes was studied.

  Methods  Culture formed keloid cutin cells (KK) and normal skin cutin cell (NK cells), built the Smad7 too slow virus slow virus vector and Smad7 interference expression vector, screening the best expression and interfering with the slow virus infection NK and KK cells respectively, and contrast carrier puro screening stable expression cell lines, stem cells can be divided into 8 groups: NK-Control (normal training of NK cells); NK-NC (NK cells screened against lentivirus); NK-shSmad7 (NK cells that interfere with lentivirus screening); NK-mSmad7 (NK cells screened for overexpression of lentivirus); KK-control (normal cultured KK cells); KK-NC (KK cells screened against lentivirus); KK-shSmad7 (KK cells that interfere with lentivirus screening); KK-mSmad7 (KK cells screened for overexpression of lentivirus). Cell proliferation was observed by the CCK-8 method, cell apoptosis was detected by flow cytometry, cell migration ability was detected by Transwell chamber, and expression of key proteins (N-cadherin and Occludin) in epithelium-interstitial transform was detected by Western blot.

  Results  The Smad7 interfering lentivirus vector and Smad7 overexpressing lentivirus vector were successfully constructed. Interference with Smad7 can promote NK cell and KK cell proliferation and migration, and inhibit KK cell apoptosis, but it has no significant effect on NK cell apoptosis (P>0.05). Overexpression of Smad7 inhibited the proliferation and migration of NK cells and KK cells, and promoted their apoptosis. After interfering with lentivirus infection, NK cells and KK cells showed decreased expression of Occludin protein compared with NC group (P<0.01), increased N-cadherin protein expression in KK cells (P<0.01), but there was no significant change in N-cadherin protein expression in NK cells (P>0.05); After lentivirus overexpression, NK and KK cells showed increased expression of Occludin protein (P<0.05), the expression of N-cadherin protein in NK cells decreased (P<0.05), but there was no significant change in N-cadherin protein expression in KK cells (P>0.05).

  Conclusion  The regulation of Smad7 gene can affect the EMT in normal skin keratinocytes and keloid keratinocytes, and further regulate the ability of cell proliferation, migration and apoptosis. The effect of Smad7 gene regulation on EMT in keloid keratinocytes was greater than that on normal skin keratinocytes.