Ontrols. Metastasis status and cigarette smoking do not affect serum PON
Ontrols. Metastasis status and cigarette smoking do not affect serum PON1 activity in the LC patients.BackgroundLung cancer (LC) is among the most common malignancies in the Western World and is the leading cause of cancer deaths in both men and women. It is one of the few tumors with a known carcinogen, namely tobacco, contributing to its etiology. Since cigarette smoking was notedin 80 to 90 of patients with LC, the leading cause of LC is Procyanidin B1 chemical information accepted to PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28151467 be smoking [1,2]. An elevated oxidative status has been found in many types of cancer cells, and the introduction of chemical and enzymatic antioxidants can inhibit tumour cell proliferationPage 1 of(page number not for citation purposes)BMC Cancer 2007, 7:http://www.biomedcentral.com/1471-2407/7/[3]. High doses and/or inadequate removal of reactive oxygen species (ROS) result in oxidative stress, which may cause severe metabolic malfunctions and damage to biological molecules including DNA [4]. It is well known that oxidative stress induced by environmental carcinogen exposure may affect cellular functions in various pathological conditions, including cancer [5,6]. Human serum paraoxonase (PON1) and arylesterase (ARE) are esterase enzymes that have lipophilic antioxidant characteristics. Serum PON1 binds to high density lipoprotein (HDL) and contributes to the elimination of organophosphorus compounds, such as paraoxon, and carcinogenic lipid soluble radicals from lipid peroxidation. PON1 is one of the endogenous free-radical scavenging systems in the human body [7-9]. Serum PON1 together with ARE have been demonstrated to function as a single enzyme [10]. PON1 activity varies widely among individuals, partly related to polymorphisms. The PON1 gene has two common coding region polymorphisms [11]. A genetic polymorphism of PON1 activity determines high versus low paraoxon hydrolysis in human populations [12]. PON1 also has ARE activity, which does not exhibit activity polymorphism and can therefore serves as an estimate of enzyme protein [13]. Human serum PON1 shows neither age-related change in activity nor gender differences [14]. However, diet, cigarette smoking, acute phase proteins, and pregnancy affect serum PON1 levels and activities [15-17]. Reduced PON1 activities have been reported in several groups of patients with diabetes mellitus, hypercholesterolemia and cardiovascular disease who are under increased oxidative stress [18,19]. There are relatively few studies on in PON1 activity in cancer. Serum levels of PON1 were lower in patients with pancreatic or gastric cancer than in healthy controls in two case-control studies. Despite these initial findings, the interaction of serum PON1 levels with cancer is not completely known [15,20,21]. It has been emphasized that PON1 polymorphisms might contribute to the increased risk of cancer in associated with pollutants and other environmental chemicals [22]. The aim of this study was to investigate the activity of serum PON1 in patients with LC, compared to that of healthy controls, and to investigate possible alterations in relation to the stage and type of LC.three of them were also not eligible for the study due to history of taking chemotherapy. The remaining 39 patients with previously untreated, histopathologically verified newly diagnosed as of LC and 39 age- and sexmatched healthy volunteers were enrolled into this study. Informed consents were obtained from patients prior to the study. The study protocol and the procedures we.