深Ⅱ度烧伤早期及愈后增生性瘢痕组织中p16基因表达的甲基化调控

目的：了解深Ⅱ度烧伤愈合早期及愈合后不同时期增生性瘢痕基因组中抑癌基因p16甲基化程度．方法：深Ⅱ度烧伤临床标本取材在烧伤后17，30，44d及愈后4，8，18，32mo增生性瘢痕组织，每组5例，用DNA甲基化特异性PCR(methylation—specific PCR，MS PCR)动态观察基因组中p16基因甲基化情况．结果：与正常组织相比，p16基因甲基化水平在深Ⅱ度烧伤愈合前17，30d组织中显增高；在愈后4mo增生性瘢痕组织中，p16基因的甲基化水平显降低，在8mo以后的增生性瘢痕组织中逐渐增高，瘢痕增生时间越长，甲基化程度越高．结论：p16基因在烧伤愈合早期高甲基化可能与促进愈合有关，在4mo增生瘢痕中低甲基化可能对快速的瘢痕增生有抑制作用，8mo以后逐渐增高的甲基化水平可能是瘢痕继续增生的重要原因．

Methylation control of p16 gene expression in early phase of deep second degree burn and hypertrophic scar after burn healing

AIM: To investigate the methylation level of p16 gene,one tumor suppressing gene in genome,in early phase of deep second burn and different phases of hypertrophic scars after burn healing.METHODS: Samples of 17 d ,30 d and 44 d were selected as early phase of deep second degree burn and the samples of 4 mo,8 mo,18 mo and 32 mo as different phases of hypertrophic scars.Five cases were assigned to each group and the methylation level of p16 gene was observed by methylation specific polymerase chain reaction (MS PCR).RESULTS: The p16 gene methylation level was significantly higher in 17 d and 30 d after burn.It was lower in 4 mo but higher in 18 mo and 32 mo of hypertrophic scars,compared with that in normal skin.CONCLUSION: The high methylation level of p16 gene in early phase of deep second degree burn may promote the wound healing.The low methylation level of p16 gene in 4 mo hypertrophic scars may suppress the rapid growth of hypertrophic scars.But the high methylation level of p16 gene in 8 mo hypertrophic scar may be responsible for the rapid growth of hypertrophic scars.