Objective: To study the situation of the mutations in the A((8)) and A((9)) loci of exon 8 of retinoblastoma protein-interacting zinc finger gene (RIZ) of keloid patients. Methods: From January 2003 to December 2007, 19 outpatient and hospitalized keloid patients of our hospital were conforming to the inclusion criteria. Both 3-5 g keloid tissue and 3 mL peripheral venous blood were collected from each patient to extract their genomic DNA, and the concentration was determined. The A((8)) and A((9)) loci fragments of exon 8 of RIZ were amplified by polymerase chain reaction (PCR). The length of product was detected by agarose gel electrophoresis, and DNA sequencing was performed after column chromatography. The mutations of A((8)) and A((9)) loci fragments were searched, and the types of mutations were determined. The consistency of genetic mutations of the keloid tissue and peripheral venous blood were compared. Data were processed with McNemar test. Results: The DNA concentrations of the extracted keloid tissue and peripheral venous blood were 0.54 and 0.37 μg/μL, respectively, which were above 0.10 μg/μL. The lengths of PCR products of A((8)) locus fragment DNA of exon 8 of RIZ from keloid tissue and peripheral venous blood were 235 and 238 bp, respectively, and those of A((9)) locus were 242 and 244 bp, respectively, which were basically the same as the designed DNA fragments. PCR products purity of A((8)) locus fragment DNA of exon 8 of RIZ from keloid tissue and peripheral venous blood were 1.81 and 1.75, respectively, and those of A((9)) locus were 1.82 and 1.78, respectively, which were above 1.50. Mutations in the A((8)) locus of exon 8 of RIZ were observed in keloid tissue of 18 patients, totally 6 gene mutations, including 4 point mutations and 2 frameshift mutations. Mutations in the A((9)) locus of exon 8 of RIZ were observed in keloid tissue of 9 patients, totally 9 gene mutations, including 7 point mutations and 2 frameshift mutations. No patient had a mutation in the A((8)) or A((9)) locus of exon 8 of RIZ in peripheral venous blood. Compared with those of peripheral venous blood, the mutations in the A((8)) and A((9)) loci of exon 8 of RIZ in keloid tissue of patients were statistically significant (χ(2)=16.06, 7.11, P<0.05). Conclusions: Point mutations and frameshift mutations occur in the A((8)) and A((9)) loci of exon 8 of RIZ in keloids of patients, which may be associated with the occurrence of keloids.
目的： 研究瘢痕疙瘩患者视网膜母细胞瘤蛋白结合锌指结构基因(RIZ)第8外显子A((8))和A((9))位点突变情况。 方法： 2003年1月—2007年12月，笔者单位收治符合入选标准的门诊及住院瘢痕疙瘩患者19例。采集患者瘢痕疙瘩组织3～5 g、外周静脉血3 mL，分别提取基因组DNA并测定浓度，PCR法扩增获取RIZ第8外显子A((8))和A((9))位点片段，产物行琼脂糖凝胶电泳检测大小，柱层析法纯化后进行DNA测序，寻找A((8))和A((9))位点片段突变，并判定突变种类和类型，对比瘢痕疙瘩组织和外周静脉血的基因突变是否一致。对数据行McNemar检验。 结果： 提取的瘢痕疙瘩组织和外周静脉血DNA质量浓度分别为0.54、0.37 μg/μL，均>0.10 μg/μL；瘢痕疙瘩组织和外周静脉血RIZ第8外显子A((8))位点片段DNA的PCR产物大小分别为235、238 bp，A((9))位点分别为242、244 bp，与所设计DNA片段大小基本一致；瘢痕疙瘩组织和外周静脉血RIZ第8外显子A((8))位点片段DNA的PCR产物纯度分别为1.81、1.75，A((9))位点分别为1.82、1.78，均>1.50。18例患者瘢痕疙瘩组织RIZ第8外显子A((8))位点发生突变，共6种基因突变，包括4种点突变、2种移码突变；9例患者瘢痕疙瘩组织RIZ第8外显子A((9))位点发生突变，共9种基因突变，包括7种点突变、2种移码突变。无一例患者外周静脉血RIZ第8外显子A((8))、A((9))位点发生突变。与外周静脉血比较，患者瘢痕疙瘩组织RIZ第8外显子A((8))和A((9))位点的突变均有统计学意义(χ(2)＝16.06、7.11，P<0.05)。 结论： 患者瘢痕疙瘩RIZ第8外显子A((8))和A((9))位点发生点突变和移码突变，这可能与瘢痕疙瘩的发生有关。.
Keywords: DNA mutational analysis; Keloid; Retinoblastoma protein-interacting zinc finger gene; Squencing.