Zhou Q, Elzagheid A, Jalava P, Sundfors C, Huang D, Syvaoja JE, Collan Y
Department of Pathology, Turku, Finland
Exp Oncol 2003; 25(3): 206-210
The aim: to study the potential mutations associated with conserved exon regions of the catalytic unit of human polymerase e in human breast cancer tissue samples. Methods: 157 DNA samples from human breast cancers and 133 DNA control samples (lymph node, placenta) were analysed with the PCR-SSCP methodology for mutation in the highly conserved regions of the polymerase e gene. The analysis involved 14 different primer pairs for the large unit of polymerase e gene and 35% of the reading frames of the catalytic unit was scanned. Results: Only 1 mutated triplet was detected in 1 breast cancer sample, it was in one of the zinc finger regions, and showed a C to T transition at nucleotide 715, which did not affect the deduced amino acid. There was no evidence of polymorphism in control samples. The optimal performance of the SSCP methodology was confirmed in the exonuclease I region of the polymerase epsilon gene in 92 cases of breast cancer, which did not show evidence of mutation in SSCP analysis or in DNA sequencing. Conclusion: the conserved areas of the human DNA polymerase e catalytic subunit require highly conserved structure for optimal function and are not involved in breast cancer progression.
Keywords: human DNA polymerase epsilon, breast cancer, mutation analysis