Abstract

Paraoxonase 1 (PON1) is a well recognised member of human endogeneous free radical scavenging systems and its polymorphism and enzyme activity are attributed to various different cancer formations. We aimed to study the Paraoxonase 1 (PON1) polymorphism and enzyme activity in colorectal cancer patients. Peripheral blood samples for DNA extraction were collected from 54 colorectal cancer patients and 85 healthy individuals. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques were used for determination of the PON1192 polymorphism. The frequency of AA genotype was greater than BB and AB genotypes in all groups (n:65 with 46.8%; n:15 with 10.8% and n:59 with 42.4%, respectively). In both tumor groups, PON activities were significantly lower than the control group (p < 0.05). The AA genotype was significantly more frequent than the AB and BB genotypes in colorectal cancer patients. Although the rectum cancer patients’ number is low in our study, we hypothesise that decreased enzyme activity of PON 1 related to 192 gene polymorphisms might have a role in the formation of an oxidative microenvironment for cancerous DNA damage which may tend to increase distally in the colon. Further studies considering the location and the stage of the colorectal tumors with more patients may put a broadly wider view on this polymorphism and enzyme activity with respect to cancer formation.

摘要

对氧磷酶1（PON1）是人类内源性自由基清除系统的公认成员，其多态性和酶活性归因于各种不同的癌症形成。我们旨在研究大肠癌患者中对氧磷酶1（PON1）的多态性和酶活性。从54位大肠癌患者和85位健康个体中采集用于DNA提取的外周血样品。聚合酶链反应（PCR）和限制性片段长度多态性（RFLP）技术用于确定PON1192多态性。在所有组中，AA基因型的频率均高于BB和AB基因型（n：65，占46.8％； n：15，占10.8％； n：59，占42.4％）。在两个肿瘤组中，PON活性均显着低于对照组（p <0.05）。在结直肠癌患者中，AA基因型的频率明显高于AB和BB基因型。尽管在我们的研究中直肠癌患者的数量很低，但我们假设与192个基因多态性相关的PON 1酶活性下降可能在形成癌性DNA损伤的氧化微环境中起作用，该环境可能会在远端向远端增加。结肠。考虑更多患者的结直肠肿瘤的位置和分期的进一步研究可能会在这种多态性和与癌症形成有关的酶活性方面有更广泛的观点。