Wang Xu, Wang Jie, Dong Fu-sheng, Dong Yu-ying, Hou Ya-li
Department of Oral Pathology, College of Stomatology, Hebei Medical University, Shijiazhuang 050017, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2007 Mar;42(3):144-7.
To analyze the original mutated codon of p53 gene of salivary pleomorphic adenoma (SPA) and to evaluate the repair effects of wt-p53 on SPA cells.
Four cases of SPA were obtained from clinical fresh samples and SPA cells were separated and cultured, and then the cells were transduced by Ad-wt-p53. The cells and the corresponding tumor tissue DNA were extracted, PCR and single strand conformational polymorphism (SSCP) and DNA sequencing analysis were performed.
PCR-SSCP analysis showed 3 out of 4 SPA with abnormal exon 8 and abnormal exon 6. DNA sequencing analysis showed that exon 6 point mutation was found at codon 203 (GTG-->GCG), poly-codon mutations were found in exon 8 at codon 272 (GTG-->GT square), 275 (TGT-->T square T), 276 (GCC--> square CC) and at codon 290 (CGC-->CGCC). After transduced by Ad-wt-p53, all of the mutated codons were repaired.
p53 gene mutation involved many codons that occurred frequently in the tumorigenesis of SPA. Exogenous wt-p53 could compensate and repair all the mutated p53 codons of SPA cells. SPA cells transduced by Ad-wt-p53 showed the typical apoptosis.
分析涎腺多形性腺瘤（SPA）中p53基因的原始突变密码子，并评估野生型p53对SPA细胞的修复作用。
从临床新鲜标本中获取4例SPA，分离培养SPA细胞，然后用Ad-wt-p53转导细胞。提取细胞及相应肿瘤组织的DNA，进行聚合酶链反应（PCR）、单链构象多态性（SSCP）分析及DNA测序。
PCR-SSCP分析显示，4例SPA中有3例第8外显子和第6外显子异常。DNA测序分析显示，第6外显子在密码子203（GTG→GCG）处发生点突变，第8外显子在密码子272（GTG→GT□）、275（TGT→T□T）、276（GCC→□CC）和290（CGC→CGCC）处发生多密码子突变。经Ad-wt-p53转导后，所有突变密码子均得到修复。
p53基因突变涉及多个密码子，在SPA的肿瘤发生过程中频繁出现。外源性野生型p53可补偿并修复SPA细胞中所有突变的p53密码子。经Ad-wt-p53转导的SPA细胞呈现典型的凋亡现象。
