转化生长因子-β_1Ⅱ型受体基因在瘢痕疙瘩中改变的实验研究

The empirical study on mutation of transforming growth factor-β_1 receptor type Ⅱ of keloid

目的通过检测瘢痕疙瘩中的转化生长因子-β1Ⅱ型受体(TβRⅡ)PolyA与CA重复序列两个基因突变热点的改变情况,论证瘢痕疙瘩是否与肿瘤具有相同的基因改变。方法选取瘢痕疙瘩标本20例、正常皮肤标本8例,提取标本中的DNA;在TβRⅡ基因PolyA位点和CA重复序列两个突变热点两侧设计并合成引物,利用PCR仪扩增,对PCR产物进行单链构象多态性分析(PCR-SSCP),PCR产物纯化后自动测序仪鉴定基因突变的位点和类型。结果PCR-SSCP显示,20例瘢痕疙瘩标本的TβRⅡPolyA位点有4例、CA重复序列有1例显示泳动条带较正常加快,且均缺失了1bp;基因测序发现,4例SSCP阳性的瘢痕疙瘩标本TβRⅡPolyA位点均出现一个A的缺失突变,正常皮肤基因序列正常;CA重复序列基因测序未见异常。结论瘢痕疙瘩组织中的TβRⅡPolyA和CA重复序列位点表现出类似肿瘤中所发现的基因缺失突变。

Objective To investigate the evidence that the keloid＇s occurrence is similar to the tumor on the two kinds of gene mutation （poly A rote and CA repeated sequence） by detecting transforming growth factor- β1 receptor type Ⅱ（TβR Ⅱ ） of keloid. Methods Twenty samples of keloid and 8 samples of normal skin were collected and then DNA was extracted from them. Dsigning and synthesizing the primers of poly A site and CA repeated sequence and then amplifying by PCR, analyzed the single strand conformation polymorphism about the products of PCR. After purifying the product of PCR whose SSCP was positive, we sequenced it directly on the automatic sequencing equipment to define the site and types of the gene mutation. Results It has been found that the strap＇s position was abnormal at poly A site in 4 cases and CA repeated sequence in 1 case, whose electrophoresis speed was all faster than that of the normal skin cases and rerabnormality was short of 1 bp. Comparing the 4 cases found positive in poly A site by SSCP with the GENE BANK sequence, we found that there was mutation at the sequence - only 9 A at poly A site. At CA repeated sequence, the gene sequencing was normal. The contrast groups were normal. Conclusion It has been concluded that keloid and tumor have homology from the mutation of poly A site and CA repeated sequence.