Liu Yongbo, Gao Jianhua, Liu Xiaojun, Lu Feng, Liu Hongwei
Department of Plastic Surgery, Nangfang Hospital, Southern Medical University, Guangzhou Guangdong 510515, PR China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2008 Dec;22(12):1433-6.
To observe the effect of gene expression of p53 and the polymorphism of p53 gene codon 72 on clinical phenotype of keloids.
The tissue and blood samples were taken from 35 patients with keloids, 19 males and 16 females, and the course of disease was from 4 months to 8 years. Meanwhile, autologous peripheral blood was collected for genotype analysis. According to the observing scope, the tissue samples of the keloids were divided into 2 groups: the central group involving the central part of the keloids (the central area within two-thirds of the radius) and the peripheral group involving the peripheral part of the keloids (the peripheral area within one-third of the radius). According to the largest diameter of the keloids, the two groups were divided into 3 subgroups: the small size group with 5 patients (< 1 cm), the medium size group with 21 patients (1-3 cm) and the large size group with 9 patients (> 3 cm). DNA of the tissue and blood samples were extracted, and the PCR followed by DNA sequencing was used to detect the polymorphism of p53 gene codon 72. The expression change of P53 was detected by immunohistochemical staining. The fibroblast apoptosis in keloid tissues was detected by TUNEL method.
The genetic genotype of p53 gene codon 72 in keloids included Arg/Arg in 7 cases, Pro/Arg in 21 cases, Pro/ Pro in 7 cases. The significant correlation was found between genotype and clinical phenotype (P < 0.05). Immunohistochemical staining revealed that P53 was detectable in peripheral and central groups of small-medium size keloids and central groups keloids, and detectable in few cells in peripheral groups of large size keloids. The absorbency value was 3 439.359 8 +/- 538.527 5 in Arg/Arg genotype, 3 273.186 2 +/- 375.213 9 in Arg/Pro genotype, 1 691.372 9 +/- 98.989 3 in Pro/Pro genotype. There were significant differences among the three genotypes (P < 0.05). The fibroblast apoptosis was detected by TUNEL, and the apoptotic cells were evenly distributed. The apoptosis index was 31.000 0 +/- 3.266 0 in peripheral group of large size keloids, 42.300 0 +/- 4.354 8 in peripheral group of medium size keloids, 44.600 0 +/- 5.253 6 in peripheral group of small size keloids. There were significant differences among the three groups (P < 0.05).
There is close relationship between the clinical phenotype of keloids and the expression of P53. The polymorphism variation of p53 gene codon 72 is beneficial for apoptosis of fibroblasts in keloids.
观察p53基因表达及p53基因密码子72多态性对瘢痕疙瘩临床表型的影响。
选取35例瘢痕疙瘩患者的组织和血液样本，其中男性19例，女性16例，病程4个月至8年。同时采集自体外周血进行基因分型分析。根据观察范围，将瘢痕疙瘩组织样本分为2组：中央组，涉及瘢痕疙瘩中央部分（半径三分之二以内的中央区域）；外周组，涉及瘢痕疙瘩外周部分（半径三分之一以内的外周区域）。根据瘢痕疙瘩最大直径，将两组再分为3个亚组：小尺寸组5例（<1 cm）、中尺寸组21例（1 - 3 cm）、大尺寸组9例（>3 cm）。提取组织和血液样本的DNA，采用聚合酶链反应（PCR）及DNA测序检测p53基因密码子72的多态性。采用免疫组织化学染色检测P53的表达变化。采用TUNEL法检测瘢痕疙瘩组织中的成纤维细胞凋亡情况。
瘢痕疙瘩中p53基因密码子72的基因基因型包括：7例为Arg/Arg、21例为Pro/Arg、7例为Pro/Pro。基因型与临床表型之间存在显著相关性（P<0.05）。免疫组织化学染色显示，中小尺寸瘢痕疙瘩的外周组和中央组以及瘢痕疙瘩中央组可检测到P53，大尺寸瘢痕疙瘩外周组仅在少数细胞中可检测到P53。Arg/Arg基因型的吸光度值为3439.3598±538.5275，Arg/Pro基因型为3273.1862±375.2139，Pro/Pro基因型为1691.3729±98.9893。三种基因型之间存在显著差异（P<0.05）。采用TUNEL法检测成纤维细胞凋亡，凋亡细胞分布均匀。大尺寸瘢痕疙瘩外周组凋亡指数为31.0000±3.2660，中尺寸瘢痕疙瘩外周组为42.3000±4.3548，小尺寸瘢痕疙瘩外周组为44.6000±5.2536。三组之间存在显著差异（P<0.05）。
瘢痕疙瘩的临床表型与P53表达密切相关。p53基因密码子72的多态性变异有利于瘢痕疙瘩中成纤维细胞的凋亡。
