A Mutation In The Keratin 13 Gene In Familial White Sponge Nevus

OBJECTS: Finding the mutation of white sponge nevus(WSN) to help to discuss the relation between the mutation and the expression of keratin 13.MATERIALS AND METHODS: We collected a WSN family, which consisted of 2 patients with WSN out of 9 people. We extracted 5ml peripheral venous blood of five people in this family to be experimental group, and we still extracted 5ml of other three healthy people out of the family to be control group. After PCR amplification we compared with the normal human genome to find the mutation.Through comparative study on expression of keratin 13 of normal oral mucosa tissues, oral leukoplakia mucosal tissue and the oral mucosa of white sponge nevus, we can tell the difference.We also used RNAi lent virus as a tool, building mutation carries of keratin 13 gene to infect Ha Ca T. Then we compared with the normal cells about the expression of keratin 13 by western blot and the efficiency of cell proliferation by MTT.RESULTS: We found 1 meaningful genetic mutation, It was c.T3222C(p.L409P) in keratin 13 gene. Through comparative study on expression of keratin 13 of normal oral mucosa tissues, oral leukoplakia mucosal tissue and the oral mucosa of white sponge nevus, we found the expression of keratin 13 were lower in spinous layer(p<0.05). And we successfully built the cell model of keratin 13 gene knock-down and keratin 13 gene c.T3222C(p.L409P) mutation. The cells of gene knock-down model showed no expression of keratin 13 and the cells of gene mutation model showed lower expression of keratin 13. On the other side, the result of MTT showed that the cells of gene mutatin model and knock-down model had a higher efficiency of cell proliferation compared with the blank control group(p<0.05).CONCLUSIONS: The genes of keratin 13 in the white sponge nevus of our study do have mutations c.T3222C(p.L409P). And our cell models give a new trail in the study of the relation between the keratin 13 gene mutation and the expression of keratin 13 and higher efficiency of cell proliferation, explain the epithelial thickening of the oral mucosa.