Aim: To observe the variation of DNA polymerase beta (polbeta) in esophageal carcinoma.
Methods: Thirty specimens containing adjacent normal epithelial tissues were collected from patients in Linzhou region (a high risk area for esophageal squamous carcinoma) and 25 specimens were from a non-high risk area. Total RNA was extracted from the samples and reverse transcription polymerase chain reaction (RT-PCR) was performed. PCR products were cloned and sequenced to investigate the polbeta gene with DNASIS and OMIGA. Statistical significance was evaluated using the chi(2) test.
Results: High-incidence area group: polbeta gene variation was detected in 13 of 30 esophageal carcinoma tissue specimens, and only one variation was found in 30 corresponding adjacent normal tissue specimens. Non high-incidence area group: polbeta gene variation was detected in 5 of 25 esophageal carcinoma tissue specimens, and no variation was found in 25 corresponding adjacent normal tissue specimens. The incidence of polbeta gene variation observed in the high-incidence area group was significantly higher than in the non-high incidence area group. Two mutation hot spots (454-466 and 648-670 nt) and a 58 bp deletion (177-234 nt) were found.
Conclusion: Variations of polbeta perform different functions between the high-incidence areas and the other areas, and may play a more important role in the high-incidence areas.