Meta-analysis of cytochrome P-450 2C9 polymorphism and colorectal cancer risk

Single-nucleotide polymorphism in CYP1A1, CYP1B1, CYP2B6, CYP2C8, and CYP2C9 genes and their association with gastrointestinal cancer: A hospital-based case-control study

BACKGROUND

Cytochrome P450 (CYP) comprises a group of phase-I metabolizing enzymes that are important in xenobiotics metabolism. Genetic polymorphism of CYPs has been comprehensively studied for their association with a range of diseases. In this study, we assessed single-nucleotide polymorphism (SNP) of CYP1A, CYP1B, CYP2B, and CYP2C and their role in gastrointestinal (GI) cancer susceptibility in the rural population of Maharashtra.

MATERIALS AND METHODS

In this hospital-based case-control study, the association of polymorphism of CYP genes was studied by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The study subjects included 200 clinically confirmed GI cancer patients and equal number of healthy controls. Odds ratio (OR) with 95% confidence interval (CI) and P value were evaluated to find out the level of association, where P ≤ 0.005 was considered statistically significant.

RESULTS

After the analysis of CYP1A1*2A (rs4646903), CYP1B1*3 (rs1059836), CYP2B6*5 (rs3211371), CYP2C8*2 (rs11572103), CYP2C9*2 (rs1799853), and CYP2C9*3 (rs1057910), we noticed that variant (T) allele of CYP2B6*5 possessed significantly elevated risk (OR = 4.43; 95% CI: 2.20-8.90; P < 0.0001) of GI cancer in studied population. The genotypic distribution of G/C heterozygote allele of CYP1B1*3 (OR = 0.19, 95% CI = 0.12-0.32; P < 0.0001) and homozygous variant C/C allele (OR = 0.24, 95% CI = 0.13-0.45; P < 0.0001) showed a negative association with the development of GI cancer.

CONCLUSION

The findings from this study supported that polymorphism of CYP2B6*5gene may be involved in the development of GI cancer. However, other SNPs of CYP1A, CYP1B, and CYP2C genes did not signify the risk for GI cancer in the studied population of rural Maharashtra.

Metabolism pathways of arachidonic acids: mechanisms and potential therapeutic targets

The arachidonic acid (AA) pathway plays a key role in cardiovascular biology, carcinogenesis, and many inflammatory diseases, such as asthma, arthritis, etc. Esterified AA on the inner surface of the cell membrane is hydrolyzed to its free form by phospholipase A2 (PLA2), which is in turn further metabolized by cyclooxygenases (COXs) and lipoxygenases (LOXs) and cytochrome P450 (CYP) enzymes to a spectrum of bioactive mediators that includes prostanoids, leukotrienes (LTs), epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acid (diHETEs), eicosatetraenoic acids (ETEs), and lipoxins (LXs). Many of the latter mediators are considered to be novel preventive and therapeutic targets for cardiovascular diseases (CVD), cancers, and inflammatory diseases. This review sets out to summarize the physiological and pathophysiological importance of the AA metabolizing pathways and outline the molecular mechanisms underlying the actions of AA related to its three main metabolic pathways in CVD and cancer progression will provide valuable insight for developing new therapeutic drugs for CVD and anti-cancer agents such as inhibitors of EETs or 2J2. Thus, we herein present a synopsis of AA metabolism in human health, cardiovascular and cancer biology, and the signaling pathways involved in these processes. To explore the role of the AA metabolism and potential therapies, we also introduce the current newly clinical studies targeting AA metabolisms in the different disease conditions.

An update on the pharmacogenomics of NSAID metabolism and the risk of gastrointestinal bleeding

Introduction: Several reports suggest a possible association between polymorphisms in the cytochrome P450 2C9 (CYP2C9) gene and the risk for non-steroidal anti-inflammatory drug (NSAID)-related adverse gastrointestinal events, including gastrointestinal bleeding. Because findings were controversial, a systematic review and a meta-analysis of eligible studies on this putative association was conducted.Areas covered: The authors have revised the relationship between CYP2C9 polymorphisms and the risk of developing NSAID-related gastrointestinal bleeding, as well as other adverse gastrointestinal events, and performed meta-analyzes. The bias effect and potential sources of heterogeneity between studies was analyzed.Expert opinion: Individuals classified as poor metabolizers after CYP2C9 genotyping (activity scores equal to 0 or 0.5) have an increased risk of developing NSAID-related gastrointestinal adverse events with an odds ratio (OR) = 1.86, (p = 0.004) and the OR for subjects with gastrointestinal bleeding is = 1.90, (p = 0.003). Gene-dose effect for variant CYP2C9 alleles (p = 0.005 for all gastrointestinal adverse events, and p = 0.0001 for bleeding patients) was observed. Also, there is an allele-specific effect in the association: CYP2C9*2 is a poor risk predictor, whereas CYP2C9*3 is a highly significant predictor of gastrointestinal adverse events (p = 0.006) and gastrointestinal bleeding (p = 0.0007).

Short-course neoadjuvant chemoradiotherapy and surgery are beneficial in Chinese patients: A retrospective study

Preoperative neoadjuvant chemoradiotherapy (NACR) is used to reduce tumor size for easier resection or improved resectability rates. Considering the difficulties regarding health insurance and health resources in China, an evidence-based short-course neoadjuvant chemoradiotherapy with surgery to cure patients was performed. This study compared the postoperative effects between short-course neoadjuvant chemoradiotherapy and surgery and surgery without neoadjuvant chemoradiotherapy.The current retrospective study was based on a rectal cancer database, including 274 patients diagnosed with rectal cancer between January 2014 and October 2016. Data were analyzed with respect to curative rate, postoperative recovery indicators (times to nasogastric tube, urinary catheter, and drainage tube removal and times to first oral feeding and passing of flatus postsurgery), chemoradiotherapy-related indicators [white blood cell count (WBC) and carcinoembryonic antigen (CEA) levels], and adverse effects indicators, evaluated according to Common Terminology Criteria for Adverse Events Version 4.0.There was no significant difference between the combined therapy and surgery groups (P > .05) in terms of radical resection rates and the times to urinary catheter removal and passing flatus (P > .05). Statistically significant differences (P < .05) in terms of earlier time for removal of the nasogastric and drainage tubes and time to first oral feeding were observed in the combined therapy group. The decreases in WBC and CEA levels in the combined therapy group were significantly greater than those in the surgery group 1 week after surgery (P < .05); after 1 month, the CEA decrease in the combined therapy group was significantly greater than that in the surgery group (P < .05). More patients in the combined therapy group experienced vomiting, indigestion, dehydration, oral mucositis, sensory neuritis, and alopecia compared with those in the surgery group 1 week after surgery (P < .05); after 1 month, only the incidence of alopecia was higher in the combined therapy group (P < .05).The combined therapy group demonstrated earlier postoperative recovery compared with the surgery group. Short-course neoadjuvant chemoradiotherapy with surgery may lead to postoperative treatment-related adverse effects of varying degrees; however, these adverse effects eventually improve with time.

Independent and combined effects of environmental factors and CYP2C19 polymorphisms on the risk of esophageal squamous cell carcinoma in Fujian Province of China

Background

The purpose of this study was to explore the effects of CYP2C19 gene polymorphisms and various environmental factors and their interactions on the risk of esophageal squamous cell carcinoma (ESCC) in a Chinese Han population.

Methods

A 1:2 frequency-matched case control study of 285 patients and 570 controls was conducted from June 2010 to May 2011 in AnXi of Fujian province, China. Environmental factors were investigated using a self-administered questionnaire and genotypes were determined using polymerase chain reaction restriction fragment length polymorphism based methods. Unconditional logistic regression models were used for statistical evaluation.

Results

Current or former smoking, consumption of pickled vegetables or hot beverages/food, having a first degree relative with ESCC and history of reflux esophagitis were significantly associated with increased ESCC risk, whereas tea drinking and consumption of fresh vegetables and fruits were significantly associated with decreased risk. The CYP2C19*2 GA/AA genotype was significantly more prevalent in ESCC patients and individuals with at least one copy of the CYP2C19*2 A allele had a 3.19-fold increased risk (adjusted 95% confidence interval (CI): 2.21–4.61, P < 0.001) of ESCC compared with those without this allele. We found no significant associations between CYP2C19*3 genotypes and ESCC. The Cyp2C19*2 polymorphism appeared to have a multiplicative joint effect with tea drinking and hot beverage/food consumption (gene–tea drinking: P_interaction = 0.042; hot beverage/food consumption: P_interaction = 6.98 × 10⁻⁶) and an additive joint effect with pickled vegetable consumption (interaction contrast ratio = 1.96, 95% CI: 0.12–3.80).

Conclusions

Our findings suggest that the CYP2C19*2 polymorphism plays an important role in the development of ESCC in the Chinese population, modified by tea drinking and consumption of pickled vegetables or hot beverages/food. Further studies are warranted to confirm our results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0156-3) contains supplementary material, which is available to authorized users.

Genetic variation in UGT genes modify the associations of NSAIDs with risk of colorectal cancer: colon cancer family registry

The use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with reduced risk of colorectal neoplasia. Previous studies have reported that polymorphisms in NSAID-metabolizing enzymes central to NSAID metabolism including UDP-glucuronosyltransferases (UGT) and cytochrome P450 (CYP) 2C9 may modify this protective effect. We investigated whether 35 functionally relevant polymorphisms within CYP2C9 and UGT genes were associated with colorectal cancer risk or modified the protective effect of NSAIDs on colorectal cancer susceptibility, using 1,584 colorectal cancer cases and 2,516 unaffected sibling controls from the Colon Cancer Family Registry. A three-SNP genotype in UGT1A6 (G-A-A; Ala7-Thr181-Arg184) and the Asp85 variant in UGT2B15 increased the risk of colorectal cancer (OR 3.87; 95% CI 1.04-14.45 and OR 1.34; 95% CI 1.10-1.63, respectively). We observed interactions between UGT1A3 Thr78Thr (A>G) and NSAID use (P-interaction = 0.02), a three-SNP genotype within UGT2B4 and ibuprofen use (P-interaction = 0.0018), as well as UGT2B15 Tyr85Asp (T>G) and aspirin use (P-interaction = 0.01). The interaction with the UGT2B4 and the UGT2B15 polymorphisms were noteworthy at the 25% FDR level. This study highlights the need for further pharmacogenetic studies to identify individuals who might benefit from NSAID use as part of developing effective strategies for prevention of colorectal neoplasia. © 2014 Wiley Periodicals, Inc.

Genetic variations in the xenobiotic-metabolizing enzymes CYP1A1, CYP1A2, CYP2C9, CYP2C19 and susceptibility to colorectal cancer among Turkish people

Cytochrome P450 (CYP) enzymes are genetically polymorphic and play key roles in the metabolism of xenobiotics. Colorectal cancer (CRC) is one of the most common malignant tumors in Turkey as well as in the world. In this study, it was aimed both to evaluate the effects of CYP variants on the susceptibility to CRC and to predict the individual response of the Turkish people to xenobiotics metabolized by CYP enzymes. For that, we assessed the association of CYP1A1, CYP1A2, CYP2C9, and CYP2C19 polymorphisms in patients with CRC in the Turkish population through a case-control study. Distributions of the variants were determined in 104 patients with CRC and 183 healthy volunteers. As results, CYP1A1 6235T/C was significantly associated with CRC risk (odds ratio [OR]=2.53; 95% confidence interval [CI]=0.99-6.45; p=0.046). In a haplotype-based analysis, CYP1A1 haplotype C6235-A2455 might be associated with the development of CRC (OR=2.70; 95% CI=0.58-5.90; p=0.046). We believe that the findings are the first results of CYP allele distributions in the Turkish population and provide an understanding of the epidemiological studies that correlate therapeutic approaches and etiology of CRC especially in Turkish patients.