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.