应用激光显微分割术结合PCR-SSCP技术诊断裸鼠移植瘤模型肺微转移癌灶

目的 探讨激光显微细胞分割术结合PCR-SSCP(single-strand conformation polymorphism）技术对微转移癌灶进行分子诊断的价值。方法 采用激光显微细胞分割技术分离裸鼠移植瘤模型肺部可疑病灶细胞，提取DNA，二次PCR扩增，非放射性同位素SSCP技术分析K-ras基因有无点突变。结果 肺微转移癌灶细胞出现K-ras基因突变(密码子12)，突变类型为AGT，而良性结节病灶未见K-ras突变，显示野生型K-ras基因(GGT)。结论 激光显微细胞分韵术结合PCR-SSCP技术对肺部可疑微转移癌灶进行分子诊断有重要帮助。

Identification of lung micrometastatic tumor foci in nude mice with implanted tumor using laser capture microdissection and PCR-single-strand conformation polymorphism.

OBJECTIVE: To assess the value of the laser capture microdissection (LCM) combined with polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) technique for diagnosing micrometastatic cancer cells in the lung of nude mice with implanted tumor. METHODS: Isolation of the cells from the suspected tumor loci in the lung of nude mice with implanted tumors was performed using laser capture microdissection technique, and the genomic DNA extracted from the cells was amplified by 2 sequential PCRs. Non-radioisotopic single-strand conformation polymorphism (SSCP) was subsequently performed to analyze the point mutation of K-ras gene. RESULTS: K-ras gene (codon 12) mutation in AGT was identified in the suspected metastatic cancer cells but not in the benign nodular lesion, where wild type K-ras gene (GGT) was detected. CONCLUSION: The utilization of LCM combined with PCR-SSCP technique may serve as a crucial aid for molecular diagnosis of morphologically suspicious cancer cell populations.