Roa I, Melo A, Roa J, Araya J, Villaseca M, de Aretxabala X
Unidad de Anatomía Patológica y Citopatología Hospital Temuco, Chile.
Rev Med Chil. 2000 Mar;128(3):251-8.
Gallbladder cancer frequency and mortality renders it one of the most important neoplastic diseases in Chile. P53 tumor suppressor gene has been studied in most types of cancer, but there is scarce information about it in gallbladder cancer.
To study the frequency of P53 gene mutation in gallbladder cancer in the ninth region of Chile.
In 25 pathological samples of gallbladder cancer, the direct amplification and sequencing of p53 gene exons 5,6,7,8-8 was possible.
Seventeen punctual mutations were observed in 13 cases (52%). There were 10 transitions, 5 transversions, one insertion (codon 194) and one deletion (codon 186). Eight cases had mutations in exon 5, six had mutations in exon 6, two had mutations in exon 7 and one had mutations in exons 8-9. In 14 of 25 cases, gene p53 protein was positive. When immunohistochemical expression of gene p53 protein was positive in more than 20% of cells, there was a high correlation between genetic alterations and immunohistochemical expression of the protein, with a specificity, sensitivity, positive and negative predictive values over 80%.
P53 gene mutation is observed in a high proportion of gallbladder cancers at it can be accurately detected with conventional immunohistochemical techniques. The importance of this gene in the genesis of this carcinoma should be determined studying preneoplastic lesions and early carcinomas.
胆囊癌的发病率和死亡率使其成为智利最重要的肿瘤性疾病之一。p53肿瘤抑制基因已在大多数癌症类型中得到研究，但在胆囊癌方面的相关信息却很少。
研究智利第九大区胆囊癌中p53基因突变的频率。
在25份胆囊癌病理样本中，实现了p53基因第5、6、7、8 - 9外显子的直接扩增和测序。
在13例（52%）中观察到17个点突变。其中有10个转换、5个颠换、1个插入（密码子194）和1个缺失（密码子186）。8例在第5外显子有突变，6例在第6外显子有突变，2例在第7外显子有突变，1例在第8 - 9外显子有突变。25例中有14例p53基因蛋白呈阳性。当基因p53蛋白的免疫组化表达在超过20%的细胞中呈阳性时，基因改变与蛋白免疫组化表达之间存在高度相关性，特异性、敏感性、阳性和阴性预测值均超过80%。
在高比例的胆囊癌中观察到p53基因突变，并且可以用传统免疫组化技术准确检测到。该基因在这种癌症发生中的重要性应通过研究癌前病变和早期癌来确定。
