Up-regulation of inflammatory signalings by areca nut extract and role of cyclooxygenase-2 -1195G>a polymorphism reveal risk of oral cancer

Systemic and Local Effects Among Patients With Betel Quid-Related Oral Cancer

The major predisposing factors of developing oral cancer include smoking, alcohol drinking, and betel quid chewing. Betel quid chewing could cause the abrasion and damage of oral mucosa by crude fibers, chemical insults by additive slaked lime, and arecoline from areca nut. These would lead to the local consequence of oral submucosal fibrosis, which is regarded clinically as a precancer lesion and a major cause of trismus. In addition, the components and additives in betel quid contain chemical toxins and carcinogens, which would further affect the oral mucosa and gradually develop a malignancy. Following literature review, aside from having a greater total tumor burden and more local diseases in the oral cavity and digestive tract, patients with betel quid-related oral cancer also have more systemic diseases from metabolic syndrome, hypertension, cardiovascular disease, type II diabetes mellitus, and obesity than those without this habit. In conclusion, those patients who have the history of smoking, alcohol drinking, and betel quid chewing would present much more unique clinical characteristics than those who only have a history of smoking and alcohol drinking. More attention should therefore be paid to pretreatment evaluation, treatment strategy, and posttreatment follow-up among betel quid chewers.

Association of Inflammation-Related Gene Polymorphisms With Susceptibility and Radiotherapy Sensitivity in Head and Neck Squamous Cell Carcinoma Patients in Northeast China

Background

Inflammation-related gene polymorphisms are some of the most important determinants for cancer susceptibility, clinical phenotype diversity, and the response to radiotherapy and chemotherapy. However, the relationship between these polymorphisms and head and neck squamous cell carcinoma (HNSCC) remains unclear. The aim of this study was to investigate the role of inflammation-related gene polymorphisms in the developmental risk and radiotherapy sensitivity of HNSCC.

Methods

The Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) genotyping system was used to genotype 612 individuals from a Chinese population for 28 inflammation-related gene polymorphisms.

Results

The protein kinase B (AKT1) rs1130233 TT, dominance model (CT+TT vs. CC), recessive model (TT vs. CT+CC), and rs2494732 CC genotypes were associated with reduced risk of HNSCC (P=0.014; P=0.041; P=0.043). The polymeric immunoglobulin receptor (PIGR) rs291097 GA, dominance model (GA+AA vs. GG), and rs291102 dominance model (GA+AA vs. GG) were associated with increased risk of HNSCC (P=0.025; P=0.025; P=0.040). The interleukin-4 receptor-α (IL-4RA) rs1801275 AA genotype was significantly correlated with increased radiotherapy sensitivity of HNSCC patients (P=0.030). In addition, age ≤ 60 years, non-smoker status, and normal levels of squamous cell carcinoma antigen (SCC) were found to be associated with increased radiotherapy sensitivity of HNSCC patients (P=0.033; P=0.033; P=0.030).

Conclusion

The AKT1 rs1130233, AKT1 rs2494732, PIGR rs291097, and PIGR rs291102 polymorphisms were significantly related to the risk of HNSCC. The IL-4RA rs1801275 polymorphism, age ≤ 60 years, non-smoker status, and normal levels of SCC were significantly associated with increased radiotherapy sensitivity of HNSCC.

Involvement of miR-619-5p in resistance to cisplatin by regulating ATXN3 in oral squamous cell carcinoma

MicroRNAs are major post-transcriptional regulators responsible for the development of human cancers, including OSCC. The specific role of miR-619-5p in OSCC, however, is rarely reported. Cisplatin is one of the mostly applied chemotherapy drugs of OSCC. Nevertheless, drug resistance of cisplatin following the initial chemotherapy largely restricts its clinical benefits, and the mechanism of cisplatin resistance is unclear. This study intends to explore the biological function of miR-619-5p in the development of cisplatin resistance in OSCC cell lines and a xenograft model, as well as the potential molecular mechanism. Our results showed that miR-619-5p was down-regulated in OSCC samples and cisplatin-resistant OSCC cells. Ectopically expressed miR-619-5p inhibited proliferative, migratory and invasive abilities of OSCC cisplatin-resistant cells. The putative target gene ATXN3 was predicted by bioinformatic analysis and confirmed by dual-luciferase reporter assay. Importantly, ATXN3 was responsible for the regulatory effects of miR-619-5p on biological behaviors of cisplatin-resistant OSCC cells. Moreover, miR-619-5p mimics and ATXN3-siRNA significantly enhanced ATXN3 knockdown in both HN6/CDDPR and CAL27/CDDPR cells and inhibited expression of PI3K and AKT. In vivo evidences demonstrated that intratumoral injection of miR-619-5p agomir remarkably slowed down the growth of OSCC in xenograft mice. Collectively, microRNA-619-5p was the vital regulator for regulating cisplatin resistance of OSCC, which may be served as a potential therapeutic target.

Role of Cyclooxygenase-2 in Head and Neck Tumorigenesis

The cyclooxygenase-2 (COX-2) is a potent enzyme that converts arachidonic acid to prostaglandins (PG), including PGE2, a key mediator of inflammation and angiogenesis. Importantly, COX-2 is activated in response to inflammatory stimuli, where it is also believed to promote the development and progression of head and neck cancers (HNC). COX-2 can mediate its protumorigenic effect through various mechanisms, such as inducing cell proliferation, inhibition of apoptosis, and suppressing the host’s immune response. Furthermore, COX-2 can induce the production of vascular endothelial growth factors, hence, promoting angiogenesis. Indeed, the ability of COX-2 inhibitors to selectively restrict the proliferation of tumor cells and mediating apoptosis provides promising therapeutic targets for cancer patients. Thus, in this comprehensive review, we summarized the reported differential expression patterns of COX-2 in different stages of head and neck carcinogenesis—from potentially premalignant lesions to invasive carcinomas. Furthermore, we examined the available meta-analysis evidence for COX-2 role in the carcinogenesis of HNC. Finally, further understanding of the biological processes of COX-2 and its role in orchestrating cell proliferation, apoptosis, and angiogenesis may give therapeutically beneficial insight to develop the management plan of HNC patients and improve their clinical outcomes.

Genome-wide CRISPR screens of oral squamous cell carcinoma reveal fitness genes in the Hippo pathway

New therapeutic targets for oral squamous cell carcinoma (OSCC) are urgently needed. We conducted genome-wide CRISPR-Cas9 screens in 21 OSCC cell lines, primarily derived from Asians, to identify genetic vulnerabilities that can be explored as therapeutic targets. We identify known and novel fitness genes and demonstrate that many previously identified OSCC-related cancer genes are non-essential and could have limited therapeutic value, while other fitness genes warrant further investigation for their potential as therapeutic targets. We validate a distinctive dependency on YAP1 and WWTR1 of the Hippo pathway, where the lost-of-fitness effect of one paralog can be compensated only in a subset of lines. We also discover that OSCCs with WWTR1 dependency signature are significantly associated with biomarkers of favorable response toward immunotherapy. In summary, we have delineated the genetic vulnerabilities of OSCC, enabling the prioritization of therapeutic targets for further exploration, including the targeting of YAP1 and WWTR1.

Betel quid-associated cancer: Prevention strategies and targeted treatment

Betel quid (BQ) and areca nut use are at risk of cancer. This review includes the latest evidence of carcinogenesis caused by BQ exposure, suggests possible prevention strategies. We conducted a systematic literature search in the PubMed and Web of Science databases to identify relevant articles published in the past 10 years according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Arecoline N-oxide, a metabolite of areca nut, is likely an initiator in carcinogenesis and is detoxified by N-acetylcysteine. Oral potentially malignant disorder and reactive oxygen species involved in carcinogenesis pathways may be treatable using antioxidants. Screening programs conducted by trained physicians are useful for identifying patients with early stages of oral cancer in high-risk groups. Anti-inflammatory medications may be used as chemopreventive agents in the disease-free stage after surgery. The association between survival and tumor somatic mutations in patients who chew BQ should be addressed in cancer studies. Current evidence on the natural course from BQ exposure to cancer occurrence and development provides information for developing primary, secondary, and tertiary prevention strategies against BQ-associated cancer at clinical or translational levels.

Overview of biological mechanisms of human carcinogens

This review summarizes the carcinogenic mechanisms for 109 Group 1 human carcinogens identified as causes of human cancer through Volume 106 of the IARC Monographs. The International Agency for Research on Cancer (IARC) evaluates human, experimental and mechanistic evidence on agents suspected of inducing cancer in humans, using a well-established weight of evidence approach. The monographs provide detailed mechanistic information about all carcinogens. Carcinogens with closely similar mechanisms of action (e.g. agents emitting alpha particles) were combined into groups for the review. A narrative synopsis of the mechanistic profiles for the 86 carcinogens or carcinogen groups is presented, based primarily on information in the IARC monographs, supplemented with a non-systematic review. Most carcinogens included a genotoxic mechanism.

Application of simulation-based CYP26 SNP-environment barcodes for evaluating the occurrence of oral malignant disorders by odds ratio-based binary particle swarm optimization: A case-control study in the Taiwanese population

Introduction

Genetic polymorphisms and social factors (alcohol consumption, betel quid (BQ) usage, and cigarette consumption), both separately or jointly, play a crucial role in the occurrence of oral malignant disorders such as oral and pharyngeal cancers and oral potentially malignant disorders (OPMD).

Material and methods

Simultaneous analyses of multiple single nucleotide polymorphisms (SNPs) and environmental effects on oral malignant disorders are essential to examine, albeit challenging. Thus, we conducted a case-control study (N = 576) to analyze the risk of occurrence of oral malignant disorders by using binary particle swarm optimization (BPSO) with an odds ratio (OR)-based method.

Results

We demonstrated that a combination of SNPs (CYP26B1 rs887844 and CYP26C1 rs12256889) and socio-demographic factors (age, ethnicity, and BQ chewing), referred to as the combined effects of SNP-environment, correlated with maximal risk diversity of occurrence observed between the oral malignant disorder group and the control group. The risks were more prominent in the oral and pharyngeal cancers group (OR = 10.30; 95% confidence interval (CI) = 4.58–23.15) than in the OPMD group (OR = 5.42; 95% CI = 1.94–15.12).

Conclusions

Simulation-based “SNP-environment barcodes” may be used to predict the risk of occurrence of oral malignant disorders. Applying simulation-based “SNP-environment barcodes” may provide insight into the importance of screening tests in preventing oral and pharyngeal cancers and OPMD.

Association of COX2 -765G>C promoter polymorphism and coronary artery disease in Korean population

BACKGROUND

Cyclooxygenase-2 (COX2) plays a role in the formation of prostaglandins, which contribute to the inflammation involved in atherosclerosis. However, the role of the COX2 -765G>C polymorphism in susceptibility to coronary artery disease (CAD) is controversial.

OBJECTIVE

To identify the association between COX2 -765G>C polymorphism with CAD risk in Korean patients. We recruited 622 patients who were diagnosed to have coronary artery disease and 202 controls who did not have history and vascular disease risk factors.

METHODS

Using polymerase chain reaction-restriction fragment length polymorphism, the COX2 -765G>C polymorphism was analyzed in 622 Korean patients who received percutaneous coronary intervention and in 202 healthy control subjects.

RESULTS

The GC+CC genotype frequencies of the -765G>C polymorphism were significantly different between the CAD and control groups. The COX2 -765G>C polymorphism showed peculiar associations with CAD according to the presence of hyperlipidemia and plasma folate levels. However, there were no associations between the -765G>C polymorphism and the rates of hypertension, diabetes mellitus, or homocysteine levels.

CONCLUSION

This study suggests that the COX2 -765G>C polymorphism is a possible genetic determinant for the risk of CAD, and an individual risk factor in Koreans. Thus, further association studies between the COX2 polymorphism and atherosclerotic-related diseases such as cerebrovascular or cardiovascular diseases in other races or ethnicities will be needed.

The significance of gene mutations across eight major cancer types

Mutations occur spontaneously, which can be induced by either chemicals (e.g. benzene) or biological factors (e.g. virus). Not all mutations cause noticeable changes in cellular functions. However, mutation in key cellular genes leads to developmental disorders. It is one of the main ways in which proto-oncogenes can be changed into their oncogenic state. The progressive accumulation of multiple mutations throughout life leads to cancer. In the past few decades, extensive research on cancer biology has discovered many genes and pathways having role in cancer development. In this review, we tried to summarize the current knowledge of mutational effect on different cancer types and its consequences in brief for future reference and guidance of researchers in cancer biology.

Activin A regulates the epidermal growth factor receptor promoter by activating the PI3K/SP1 pathway in oral squamous cell carcinoma cells

Epidermal growth factor receptor (EGFR) and activin A are both overexpressed in oral cavity squamous cell carcinoma (OSCC). We evaluated their clinical correlation and activin A-mediated EGFR regulation in this study. Overexpression of both transcripts/proteins indicated a poorer prognosis in OSCC patients. Knockdown of endogenous INHBA repressed the expression of EGFR and inhibited activin A-mediated canonical Smads, noncanonical phosphorylation of AKT (ser473) (p-AKT ser473) and SP1. Inhibition of PI3K signaling via its inhibitor attenuated p-AKT ser473 and in turn reduced SP1 and EGFR expression in the presence of recombinant activin A (rActivin A) in OSCC cells, as revealed via a luciferase assay and western blotting. However, canonical Smad signaling repressed the EGFR promoter, as revealed by a luciferase assay. The transcription factor SP1, its coactivator CBP/p300, and Smad proteins were recruited to the EGFR proximal promoter following rActivin A treatment, as revealed by chromatin immunoprecipitation (ChIP). Smad2/3/4 dramatically outcompeted SP1 binding to the EGFR proximal promoter following mithramycin A treatment. Activin A activates the PI3K and Smad pathways to compete for binding to overlapping SP1 consensus sequences on the EGFR proximal promoter. Nevertheless, canonical p-Smad2 was largely repressed in OSCC tumor tissues, suggesting that the activin A-mediated noncanonical pathway is essential for the carcinogenesis of OSCC.

Areca nut extracts mobilize calcium and release pro-inflammatory cytokines from various immune cells

Betel nut consumption has significant implications for the public health globally, as the wide-spread habit of Areca chewing throughout Asia and the Pacific is associated with a high prevalence of oral carcinoma and other diseases. Despite a clear causal association of betel nut chewing and oral mucosal diseases, the biological mechanisms that link Areca nut-contained molecules, inflammation and cancer remain underexplored. In this study we show that the whole Areca nut extract (ANE) is capable of mobilizing Ca²⁺ in various immune cell lines. Interestingly, none of the four major alkaloids or a range of other known constituents of Areca nut were able to induce such Ca²⁺ signals, suggesting that the active components might represent novel or so far unappreciated chemical structures. The separation of ANE into aqueous and organic fractions has further revealed that the calcium-mobilizing molecules are exclusively present in the aqueous extract. In addition, we found that these calcium signals are associated with the activation of several immune cell lines as shown by the release of pro-inflammatory cytokines and increased cell proliferation. These results indicate that calcium-mobilizing molecules present in the aqueous fraction of the Areca nut may critically contribute to the inflammatory disorders affecting betel nut chewers.

Adverse Health Effects of Betel Quid and the Risk of Oral and Pharyngeal Cancers

Global reports estimate 600 million betel quid (BQ) chewers. BQ chewing has been demonstrated not only to be a risk factor for cancers of the oral cavity and pharynx and oral potentially malignant disorders (OPMD) but also to cause other cancers and adverse health effects. Herein, we summarized the international comparison data to aid in the understanding of the close relationship between the prevalence of BQ chewing, the occurrence of oral and pharyngeal cancers, and adverse health effects. Potential biomarkers of BQ carcinogens, such as areca nut, alkaloids, and 3-methylnitrosaminopropionitrile (MNPN), are closely associated with human health toxicology. Molecular mechanisms or pathways involving autophagy, hypoxia, COX-2, NF-κB activity, and stemness are known to be induced by BQ ingredients and are very closely related to the carcinogenesis of cancers of oral and pharynx. BQ abuse-related monoamine oxidase (MAO) gene was associated with the occurrence and progress of oral and pharyngeal cancers. In summary, our review article provides important insights into the potential roles of environmental BQ (specific alkaloid biomarkers and nitrosamine products MNPN) and genetic factors (MAO) and offers a basis for studies aiming to reduce or eliminate BQ-related OPMD and oral/pharyngeal cancer incidences in the future.

Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) association with lymph node metastasis predicts poor survival in oral squamous cell carcinoma patients

Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) is a multifunctional protein aberrantly expressed in various types of cancers. However, its expression pattern and clinical significance in oral squamous cell carcinoma (OSCC) remains unclear. In this study, we immunohistochemically investigated the expression pattern of ANP32A in 259 OSCC patients and the results were correlated with clinicopathological factors using Allred, Klein and Immunoreactive scoring (IRS) system. Our data indicated that high expression of ANP32A was significantly associated with N stage and tumor differentiation status in OSCC patients. High ANP32A expression with N2/N3 stage had an increased mortality risk than low ANP32A expressing OSCC patients with N0/N1 stage. Functional studies revealed that knockdown of ANP32A significantly decreased the migration and invasion ability thereby concomitantly increasing E-cadherin and decreasing Slug, Claudin-1 and Vimentin expression in vitro. These results suggest that ANP32A is commonly increased in oral squamous cell carcinoma and ANP32A protein could act as a potential biomarker for prognosis assessment of oral cancer patients with lymph node metastasis.

Arecoline N-Oxide Upregulates Caspase-8 Expression in Oral Hyperplastic Lesions of Mice

Areca nut is strongly associated with oral squamous cell carcinoma (OSCC) occurrence. Arecoline N-oxide (ANO), a metabolite of the areca alkaloid arecoline, exhibits an oral fibrotic effect in NOD/SCID mice. Caspase-8, a cysteine protease encoded by the CASP8 gene, is a central mediator in the extrinsic apoptotic pathway via death receptors. Deregulation of caspase-8 in OSCC has been reported. This study investigates the regulation of caspase-8 in ANO-induced oral squamous epithelial hyperplasia that represents the initial highly proliferative stage of oral carcinogenesis. CASP8 somatic mutations were identified from whole-exome sequencing of OSCC samples. Immunohistochemical staining showed upregulation of caspase-8 in ANO-induced hyperplasia of both NOD-SCID and C57BL/6 mice. Levels of expression of CASP8, APAF-1, BAX, and BAD increased in ANO-treated DOK cells. Co-localization of increased caspase-8 and PCNA levels was detected in ANO-induced hyperplastic lesions, whereas no co-localization among γ-H2A.X, caspase-3, and upregulated caspase-8 was observed. The findings indicate that upregulation of caspase-8 is involved in cell proliferation rather than apoptosis during the initial stage of ANO-mediated oral tumorigenesis.

Taiwanin C selectively inhibits arecoline and 4-NQO-induced oral cancer cell proliferation via ERK1/2 inactivation

Arecoline, the most abundant alkaloid in betel nut is known to promote abnormal proliferation of epithelial cells by enhancing epidermal growth factor receptor (EGFR) activation and cyclooxygenase-2 (COX2) expression. Taiwanin C, a naturally occurring lignan extracted from Taiwania cryptomerioides, has been found to be a potential inhibitor of COX2 expression. Based on the MTT assay results, taiwanin C was found to be effective in inhibiting the tumorous T28 cell than the non-tumorous N28 cells. The modulations in the expression of relevant proteins were determined to understand the mechanism induced by taiwanin C to inhibit T28 cell proliferation. The levels of activated EGFR and COX2 were found to be abnormally high in the T28 oral cancer cells. However, taiwanin C was found to inhibit the activation of EGFR and regulated other related downstream proteins and thereby inhibited the T28 cell proliferation. In conclusion the results indicate that taiwanin C suppresses COX2-EGFR and enhances P27 pathways to suppress arecoline induced oral cancer cell proliferation via ERK1/2 inactivation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 62-69, 2017.

COX-2 rs689466, rs5275, and rs20417 polymorphisms and risk of head and neck squamous cell carcinoma: a meta-analysis of adjusted and unadjusted data

Background

Numerous case–control studies have been performed to investigate the association between three cyclooxygenase-2 (COX-2) polymorphisms (rs20417 (−765G > C), rs689466 (−1195G > A), and rs5275 (8473 T > C)) and the risk of head and neck squamous cell carcinoma (HNSCC). However, the results were inconsistent. Therefore, we conducted this meta-analysis to investigate the association.

Methods

We searched in PubMed, Embase, and Web of Science up to January 20, 2015 (last updated on May 12, 2016). Two independent reviewers extracted the data. Odds ratios (ORs) with their 95 % confidence intervals (CIs) were used to assess the association. All statistical analyses were performed using the Review Manager (RevMan) 5.2 software.

Results

Finally 8 case–control studies were included in this meta-analysis. For unadjusted data, an association with increased risk was observed in three genetic models in COX-2 rs689466 polymorphism; however, COX-2 rs5275 and rs20417 polymorphisms were not related to HNSCC risk in this study. The pooled results from adjusted data all revealed non-significant association between these three polymorphisms and risk of HNSCC. We also found a similar result in the subgroup analyses, based on both unadjusted data and adjusted data.

Conclusion

Current results suggest that COX-2 rs689466, rs5275, and rs20417 polymorphisms are not associated with HNSCC. Further large and well-designed studies are necessary to validate this association.

Somatic Mutations and Genetic Variants of NOTCH1 in Head and Neck Squamous Cell Carcinoma Occurrence and Development

A number of genetic variants have been associated with cancer occurrence, however it may be the acquired somatic mutations (SMs) that drive cancer development. This study investigates the potential SMs and related genetic variants associated with the occurrence and development of head and neck squamous cell carcinoma (HNSCC). We identified several SMs in NOTCH1 from whole-exome sequencing and validated them in a 13-year cohort of 128 HNSCC patients using a high-resolution melting analysis and resequencing. Patients who have NOTCH1 SMs show higher 5-year relapse-free recurrence (P = 0.0013) and lower survival proportion (P = 0.0447) when the risk-associated SMs were analysed by Cox proportional hazard models. Interestingly, the NOTCH1 gene rs139994842 that shares linkage with SMs is associated with HNSCC risk (OR = 3.46), increasing when SMs in NOTCH1 are involved (OR = 7.74), and furthermore when there are SMs in conjunction to betel quid chewing (OR = 32.11), which is a related independent environmental risk factor after adjusting for substances use (alcohol, betel quid, cigarettes) and age. The findings indicate that betel quid chewing is highly associated with NOTCH1 SMs (especially with changes in EGF-like domains), and that rs139994842 may potentially serve as an early predictive and prognostic biomarker for the occurrence and development of HNSCC.

Cyclooxygenase-2-1195G>A Polymorphism and Head and Neck Squamous Cell Carcinoma Susceptibility: A Meta-Analysis of 1564 Cases and 2346 Controls

Background

The aim of this study was to investigate the association between cyclooxygenase-2 (COX-2) rs689466 (–1195 G>A) polymorphism and susceptibility to head and neck squamous cell carcinoma (HNSCC) by performing a meta-analysis.

Material/Methods

PubMed and Embase were searched for relevant cohort and case-control studies up to 13 March 2015. After data extraction and methodological quality assessment for eligible studies, the overall, subgroup, sensitivity, and cumulative meta-analyses were conducted using the Comprehensive Meta-Analysis software (version 2.2).

Results

Finally, 5 case-control studies involving 1564 HNSCC patients and 2346 healthy controls were included. For overall population, the results of 3 genetic models showed significant association, while the other 2 presented negative association [A vs. G: OR=0.97–1.09, 95%CI=0.97–1.09; AA vs. GG: OR=1.26, 95%CI=1.01–1.57; AA vs. GA: OR=1.21, 95%CI=1.01–1.45); AA vs. (GG+GA): OR=1.20, 95%CI=1.01–1.43; (AA+GA) vs. GG: OR=0.98, 95%CI=0.84–1.15]. Publication bias was not assessed due to the limited number of included studies.

Conclusions

This meta-analysis indicated that COX-2 rs689466 polymorphism might be associated with increased susceptibility to HNSCC. We also suggest performing more relevant studies in order to enlarge the sample size and obtain more precise results.

Association between cyclooxygenase-2 gene polymorphisms and head and neck squamous cell carcinoma risk

Cyclooxygenase-2 (COX-2) is an inducible enzyme that catalyzes prostaglandins through inflammatory response, which may be involved in autoimmune diseases and cancer pathogenesis. Two potentially functional genetic single-nucleotide polymorphisms (COX-2 -1195G>A and 8473T>C) were supposed to contribute to head and neck squamous cell carcinoma (HNSCC) susceptibility. The aim of this study was to determine the association of these polymorphisms with HNSCC susceptibility in a Chinese Han population. In this study, 2 SNPs were genotyped by TaqMan methods in a patient-control study including 260 patients with HNSCC and 1047 cancer-free controls in a Chinese Han population. We found significant difference in the frequency of alcohol consumption between the patients with HNSCC and controls (P < 0.001), but the genotype frequencies of the 2 polymorphisms were not significantly different between the patients and controls. Further stratified analysis indicated that none of the genotypes were associated with increased risk for HNSCC. This research indicated that the COX-2 -1195G>A and 8473T>C polymorphisms may not be involved in the development of HNSCC in the Chinese Han population. However, further perspective studies are warranted to test these findings and further investigate the potential interactions involving the COX-2 polymorphism and HNSCC.

Fibrotic Effects of Arecoline N-Oxide in Oral Potentially Malignant Disorders

The metabolites of environmental chemicals play key roles in carcinogenesis. Areca nut is strongly associated with the development of oral potentially malignant disorders (OPMD) or cancer. The main alkaloid in the areca nut is arecoline, which is highly cytotoxic and genotoxic. Arecoline N-oxide, a metabolite of areca nut alkaloids, which has been identified in animal urine, has been shown to induce mutagenicity in bacteria. In this study, it was found that its protein adduct could be detected in oral keratinocytes treated with areca nut extract. Increased collagen expression and severity of squamous hyperplasia were observed in arecoline N-oxide treated mice. In cultured oral fibroblasts, arecoline N-oxide showed stronger effects on the increase of fibrotic related genes including TGF-beta1, S100A4, MMP-9, IL-6, and fibronectin and a decrease of E-cadherin as compared with arecoline. Finally, arecoline N-oxide stimulation effectively increased the DNA damage marker, gamma-H2A.X, both in vitro and in vivo. Taken together, these results indicate that arecoline N-oxide shows a high potential for the induction of OPMD.

The -765G>C polymorphism in the cyclooxygenase-2 gene and digestive system cancer: a meta-analysis

BACKGROUND

Published data regarding associations between the -765G>C polymorphism in cyclooxygenase-2 (COX-2) gene and digestive system cancer risk have been inconclusive. The aim of this study was to comprehensively evaluate the genetic risk of the -765G>C polymorphism in the COX-2 gene for digestive system cancer.

MATERIALS AND METHODS

A search was performed in Pubmed, Medline (Ovid), Embase, CNKI, Weipu, Wanfang and CBM databases, covering all studies until Feb 10, 2014. Statistical analysis was performed using Revman5.2.

RESULTS

A total of 10,814 cases and 16,174 controls in 38 case-control studies were included in this meta-analysis. The results indicated that C allele carriers (GC+CC) had a 20% increased risk of digestive system cancer when compared with the homozygote GG (odds ratio (OR)=1.20, 95% confidence interval (CI), 1.00-1.44 for GC+CC vs GG). In the subgroup analysis by ethnicity, significant elevated risks were associated with C allele carriers (GC+CC) in Asians (OR = 1.46, 95% CI=1.07-2.01, and p=0.02) and Africans (OR=2.12, 95% CI=1.57-2.87, and p< 0.00001), but not among Caucasians, Americans and mixed groups. For subgroup analysis by cancer type (GC+CC vs GG), significant associations were found between the -765G>C polymorphism and higher risk for gastric cancer (OR=1.64, 95% CI=1.03-2.61, and p=0.04), but not for colorectal cancer, oral cancer, esophageal cancer, and others. Regarding study design (GC+CC vs GG), no significant associations were found in then population-based case-control (PCC), hospital-based case-control (HCC) and family-based case-control (FCC) studies.

CONCLUSIONS

This meta-analysis suggested that the -765G>C polymorphism of the COX-2 gene is a potential risk factor for digestive system cancer in Asians and Africans and gastric cancer overall.

Functional Polymorphisms in COX-2 Gene Are Correlated with the Risk of Oral Cancer

Background. This meta-analysis investigated the association between functional COX-2 gene polymorphisms and the risk of oral cancer. Methods. Several electronic databases were searched for published studies using combinations of keywords related to COX-2 gene polymorphisms and oral cancer. After selection of relevant studies, following strict inclusion and exclusion criteria, data was performed using STATA 12.0 software. Results. We retrieved 83 studies from database search using specific search terms. After multiple rounds of selection and elimination, 7 studies were finally identified as suitable to be included in our present meta-analysis, based on their relevance and data integrity. These 7 studies contained a combined total of 2,296 oral cancer patients and 3,647 healthy controls. Our findings demonstrated that +837 T > C (rs5275) polymorphism in COX-2 showed statistically significant differences in gene frequencies in case and control groups in allele model and dominant model. Similar results were obtained with COX-2 gene polymorphism 765 G > C (rs20417). On the other hand, 1195 A > G (rs689466) polymorphism in COX-2 did not confer susceptibility to oral cancers. Conclusion. Based on our results, COX-2 gene polymorphisms, +837 T > C (rs5275) and −765G > C (rs20417), showed clear links with oral cancer susceptibility, and the 1195A > G (rs689466) polymorphism did not show such a correlation.

Association study between novel CYP26 polymorphisms and the risk of betel quid-related malignant oral disorders

BQ chewing may produce significant amounts of reactive oxygen species (ROS), resulting in oral mucosa damage, and ROS may be metabolized by CYP26 families. Because the CYP26 polymorphisms associated with malignant oral disorders are not well known, we conducted an association study on the associations between the single nucleotide polymorphisms (SNP) of CYP26 families and the risks of malignant oral disorders. BQ chewers with the CYP26A1 rs4411227 C/C+C/G genotype and C allele showed an increased risk of oral and pharyngeal cancer (adjusted odds ratio (aOR) = 2.30 and 1.93, respectively). The CYP26B1 rs3768647 G allele may be associated with oral and pharyngeal cancer (aOR = 3.12) and OPMDs (aOR = 2.23). Subjects with the rs9309462 CT genotype and C allele had an increased risk of oral and pharyngeal cancer (aOR = 9.24 and 8.86, respectively) and OPMDs (aOR = 8.17 and 7.87, respectively). The analysis of joint effects between the CYP26A1 rs4411227 and CYP26B1 rs3768647/rs9309462 polymorphisms revealed statistical significance (aOR = 29.91 and 10.03, respectively). Additionally, we observed a significant mRNA expression of CY26A1 and CYP26B1 in cancerous tissues compared with adjacent noncancerous tissues. Our findings suggest that novel CYP26 polymorphisms are associated with an increased risk of malignant oral disorders, particularly among BQ chewers.

Betel quid chewing without tobacco: a meta-analysis of carcinogenic and precarcinogenic effects

Betel quid without tobacco is an important factor influencing the incidences of oral cancer and precancer. This study systematically evaluated the associations between betel quid containing no tobacco and oral cancer and precancer, with implications for the prevention of oral cancer. We searched MEDLINE, ISI Web of Science, and EMBASE (to April 2011) and retrieved studies that investigated the relationship between chewing betel quid and oral cancer (or precancer). We performed a meta-analysis to summarize the published data and describe the prevalence of betel quid use with regard to cancerous diseases. In all, 19 eligible studies that reported odds ratios and 95% confidence intervals for oral cancer with respect to betel quid were included. The analysis identified an association suggesting that betel quid might be an important risk factor for oral cancer and precancer. The results of this review suggest that betel-chewing-cessation programs should be developed to help prevent oral diseases.

The influence of monoamine oxidase variants on the risk of betel quid-associated oral and pharyngeal cancer

Betel quid (BQ) and areca nut (AN) (major BQ ingredient) are group I human carcinogens illustrated by International Agency for Research on Cancer and are closely associated with an elevated risk of oral potentially malignant disorders (OPMDs) and cancers of the oral cavity and pharynx. The primary alkaloid of AN, arecoline, can be metabolized via the monoamine oxidase (MAO) gene by inducing reactive oxygen species (ROS). The aim of this study was to investigate whether the variants of the susceptible candidate MAO genes are associated with OPMDs and oral and pharyngeal cancer. A significant trend of MAO-A mRNA expression was found in in vitro studies. Using paired human tissues, we confirmed the significantly decreased expression of MAO-A and MAO-B in cancerous tissues when compared with adjacent noncancerous tissues. Moreover, we determined that MAO-A single nucleotide polymorphism variants are significantly linked with oral and pharyngeal cancer patients in comparison to OPMDs patients [rs5953210 risk G-allele, odds ratio = 1.76; 95% confidence interval = 1.02-3.01]. In conclusion, we suggested that susceptible MAO family variants associated with oral and pharyngeal cancer may be implicated in the modulation of MAO gene activity associated with ROS.

Methylation-associated gene silencing of RARB in areca carcinogens induced mouse oral squamous cell carcinoma

Regarding oral squamous cell carcinoma (OSCC) development, chewing areca is known to be a strong risk factor in many Asian cultures. Therefore, we established an OSCC induced mouse model by 4-nitroquinoline-1-oxide (4-NQO), or arecoline, or both treatments, respectively. These are the main two components of the areca nut that could increase the occurrence of OSCC. We examined the effects with the noncommercial MCGI (mouse CpG islands) microarray for genome-wide screening the DNA methylation aberrant in induced OSCC mice. The microarray results showed 34 hypermethylated genes in 4-NQO plus arecoline induced OSCC mice tongue tissues. The examinations also used methylation-specific polymerase chain reaction (MS-PCR) and bisulfite sequencing to realize the methylation pattern in collected mouse tongue tissues and human OSCC cell lines of different grades, respectively. These results showed that retinoic acid receptor β (RARB) was indicated in hypermethylation at the promoter region and the loss of expression during cancer development. According to the results of real-time PCR, it was shown that de novo DNA methyltransferases were involved in gene epigenetic alternations of OSCC. Collectively, our results showed that RARB hypermethylation was involved in the areca-associated oral carcinogenesis.

Expression of a splice variant of CYP26B1 in betel quid-related oral cancer

Betel quid (BQ) is a psychostimulant, an addictive substance, and a group 1 carcinogen that exhibits the potential to induce adverse health effects. Approximately, 600 million users chew a variety of BQ. Areca nut (AN) is a necessary ingredient in BQ products. Arecoline is the primary alkaloid in the AN and can be metabolized through the cytochrome P450 (CYP) superfamily by inducing reactive oxygen species (ROS) production. Full-length CYP26B1 is related to the development of oral pharyngeal cancers. We investigated whether a splice variant of CYP26B1 is associated with the occurrence of ROS related oral and pharyngeal cancer. Cytotoxicity assays were used to measure the effects of arecoline on cell viability in a dose-dependent manner. In vitro and in vivo studies were conducted to evaluate the expression of the CYP26B1 splice variant. The CYP26B1 splice variant exhibited lower expression than did full-length CYP26B1 in the human gingival fibroblast-1 and Ca9-22 cell models. Increased expression of the CYP26B1 splice variant was observed in human oral cancer tissue compared with adjacent normal tissue, and increased expression was observed in patients at a late tumor stage. Our results suggested that the CYP26B1 splice variant is associated with the occurrence of BQ-related oral cancer.

Betel-quid dependence domains and syndrome associated with betel-quid ingredients among chewers: an Asian multi-country evidence

AIMS

Betel-quid (BQ) contains biologically psychoactive ingredients; however, data are limited concerning the symptoms and syndrome of BQ dependence among chewers. The aims of this study were to evaluate the ingredients-associated BQ dependence syndrome and country-specific chewing features and behaviour for BQ dependence among chewers from six Asian communities.

DESIGN

An intercountry Asian Betel-quid Consortium study.

SETTING

Six Asian general communities in Taiwan, Mainland China, Indonesia, Malaysia, Sri Lanka and Nepal.

PARTICIPANTS

Six multi-stage random samples of BQ chewers in the Asian Betel-quid Consortium study (n = 2078).

MEASUREMENTS

All chewers were evaluated for BQ dependence using the DSM-IV and ICD-10 criteria.

FINDINGS

The 12-month BQ dependence rate was 12.5-92.6% and 47.9-99.3% (P = 0.023) among tobacco-free and tobacco-added BQ chewers across the six Asian communities, with a higher dependence rate in chewers who used tobacco-free BQ with lime added than without (23.3-95.6% versus 4.0%, P ≤ 0.001). Taiwanese and Hunanese BQ chewers both notably endorsed the dependency domain of 'time spent chewing'. 'Tolerance' and 'withdrawal' were the major dependence domains associated with the Nepalese and Indonesian chewers, with high BQ dependence rates. Malaysian and Sri Lankan chewers formed a BQ dependence cluster linked closely to 'craving'. In Sri Lanka, the quantity consumed explained 90.5% (P < 0.001) of the excess dependence risk for tobacco-added use, and could be a mediator between tobacco-derived psychoactive effect and BQ dependence development.

CONCLUSIONS

DSM-IV criteria for dependence apply to a significant proportion of betel quid users in Asian communities, more so if they use it with tobacco or lime.

Genetic polymorphisms in the prostaglandin pathway genes and risk of head and neck cancer

OBJECTIVE

Previous studies examining the association between genetic variations in prostaglandin pathway and risk of head and neck cancer (HNC) have only included polymorphisms in the PTGS2 (COX2) gene. This study investigated the association between genetic polymorphisms of six prostaglandin pathway genes (PGDS, PTGDS, PTGES, PTGIS, PTGS1 and PTGS2), and risk of HNC.

METHODS

Interviews regarding the consumption of alcohol, betel quid, and cigarette were conducted with 222 HNC cases and 214 controls. Genotyping was performed for 48 tag and functional single-nucleotide polymorphisms (SNPs).

RESULTS

Two tag SNPs of PTGIS showed a significant association with HNC risk [rs522962: log-additive odds ratio (OR) = 1.42, 95% confidence interval (CI): 1.01-1.99 and dominant OR = 1.58, 95% CI: 1.02-2.47; rs6125671: log-additive OR = 1.49, 95% CI: 1.08-2.05 and dominant OR = 1.96, 95% CI: 1.16-3.32]. In addition, a region in PTGIS tagged by rs927068 and rs6019902 was significantly associated with risk of HNC (global P = 0.007). Finally, several SNPs interacted with betel quid and cigarette to influence the risk of HNC.

CONCLUSIONS

Genetic variations in prostaglandin pathway genes are associated with risk of HNC and may modify the relationship between use of betel quid or cigarette and development of HNC.

Arecoline inhibits epithelial cell viability by upregulating the apoptosis pathway: implication for oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic inflammatory disease characterized by the accumulation of excess collagen, and areca nut chewing has been proposed as a significant etiological factor for disease manifestation. However, the underlying molecular mechanisms regarding areca nut chewing-induced OSF are only partially understood. Herein, we reported that arecoline markedly induced morphologic change in HaCaT epithelial cells, but had no obvious effect on Hel fibroblast cells. MTS assay revealed that arecoline significantly suppressed HaCaT cell viability. Moreover, flow cytometric analysis indicated that arecoline substantially promoted HaCaT cell, but not Hel cell apoptosis in a dose-dependent manner. Furthermore, arecoline-induced HaCaT cell apoptosis was found to be associated with increased expression and activation of cleaved-Bid, cleaved-PARA and cleaved-caspase-3. Collectively, our results suggest that HaCaT epithelial cells are more sensitive than Hel fibroblast cells to arecoline-induced cytotoxicity, which may be involved in the pathogenesis of OSF.

Cyclooxygenase 2 genotypes influence prostate cancer susceptibility in Japanese Men

This study aims to evaluate the relationship between the cyclooxygenase 2 (COX2) G1195A (rs689465) polymorphism and the risk of prostate cancer in a Japanese population and the associations between COX2 polymorphisms and clinicopathological characteristics, including Gleason grade and prostate-specific antigen (PSA) grade. We recruited 134 patients with prostate cancer and 86 healthy controls matched for age and smoking status. The COX2 G1195A polymorphism status was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. Genotype distributions (p = 0.028) and allelic frequencies (p = 0.014) differed significantly between prostate cancer and control groups in terms of the COX2 G1195A polymorphism (Pearson's χ (2) test). Logistic regression analysis of case and control outcomes showed an odds ratio between the GG and AA genotypes of 3.15 (95% confidence interval = 1.27-8.08, p = 0.014), indicating an increased risk of prostate cancer associated with the AA genotype. Subset analysis revealed no significant associations between this polymorphism and clinicopathological characteristics of prostate cancer. This study demonstrated a relationship between the COX2 G1195A variant and prostate cancer risk. This polymorphism may merit further investigation as a potential genomic marker for the early detection of prostate cancer. Our results support the hypothesis that rs689465 influences susceptibility to prostate cancer; however, prostate cancer progression was not associated with rs689465 in a Japanese population.

COX-2-765G>C polymorphism increases the risk of cancer: a meta-analysis

Background

Chronic inflammation has been regarded as an important mechanism in carcinogenesis. Inflammation-associated genetic variants have been highly associated with cancer risk. Polymorphisms in the gene cyclooxygenase-2 (COX-2), a pro-inflammation factor, have been suggested to alter the risk of multiple tumors, but the findings of various studies are not consistent.

Methods

A literature search through February 2013 was performed using PubMed, EMBASE, and CNKI databases. We used odds ratios (ORs) with confidence intervals (CIs) of 95% to assess the strength of the association between the COX-2-765G>C polymorphism and cancer risk in a random-effect model. We also assessed heterogeneity and publication bias.

Results

In total, 65 articles with 29,487 cancer cases and 39,212 non-cancer controls were included in this meta-analysis. The pooled OR (95% CIs) in the co-dominant model (GC vs. GG) was 1.11 (1.02–1.22), and in the dominant model ((CC+GC) vs. GG), the pooled OR was 1.12 (1.02–1.23). In the subgroup analysis, stratified by cancer type and race, significant associations were found between the-765 C allele and higher risk for gastric cancer, leukemia, pancreatic cancer, and cancer in the Asian population.

Conclusion

In summary, the COX-2-765 C allele was related to increased cancer susceptibility, especially gastric cancer and cancer in the Asian population.

Betel-quid dependence and oral potentially malignant disorders in six Asian countries

BACKGROUND

Despite gradual understanding of the multidimensional health consequences of betel-quid chewing, information on the effects of dependent use is scant.

AIMS

To investigate the 12-month prevalence patterns of betel-quid dependence in six Asian populations and the impact of this dependence on oral potentially malignant disorders (OPMD).

METHOD

A multistage random sample of 8922 participants was recruited from Taiwan, mainland China, Indonesia, Malaysia, Sri Lanka and Nepal. Participants were evaluated for betel-quid dependency using DSM-IV and ICD-10 criteria and assessed clinically for oral mucosal lesions.

RESULTS

The 12-month prevalence of dependence was 2.8-39.2% across the six Asian samples, and 20.9-99.6% of those who chewed betel-quid were betel-quid dependent. Men dominated the prevalence among the east Asian samples and women dominated the prevalence in south-east Asian samples. 'Time spent chewing' and 'craving' were the central dependence domains endorsed by the Chinese and southern/south-east Asian samples respectively, whereas the Nepalese samples endorsed 'tolerance' and 'withdrawal'. Dependency was linked to age, gender, schooling years, drinking, smoking, tobacco-added betel-quid use and environmental accessibility of betel-quid. Compared with non-users, those with betel-quid dependency had higher pre-neoplastic risks (adjusted odds ratios 8.0-51.3) than people with non-dependent betel-quid use (adjusted odds ratio 4.5-5.9) in the six Asian populations.

CONCLUSIONS

By elucidating differences in domain-level symptoms of betel-quid dependency and individual and environmental factors, this study draws attention to the population-level psychiatric problems of betel-quid chewing that undermine health consequences for OPMD in six Asian communities.

Betel-quid and oral submucous fibrosis: a cross-sectional study in Hunan province, China

BACKGROUND

The development of betel-quid (BQ) processing industry in Hunan has increased the usage of this substance and may produce significant health consequences. However, the update data for the prevalence of BQ chewing and its effect on oral submucous fibrosis (OSF) are limited.

METHODS

A population-based survey was conducted to investigate the prevalence of BQ chewing and OSF in Hunan. A questionnaire interview and an oral examination were conducted. A multivariate logistic regression model was used to study the effect of socio-demographic characteristics on area-specific behaviors of BQ chewing.

RESULTS

A total of 2356 subjects participated in this survey, with a 78.5% of response rate. The lifetime prevalence of BQ chewing was 16.2% (2.9% for ex-chewers and 13.3% for current-chewers). The findings from multivariate logistic regression model showed that a higher prevalence of this habit was among individuals who were males, urban residents, 15-49 years old, educated for 9-12 years, smokers, and drinkers. Male chewers occupied a fairly higher percentage of the combined use of tobacco and/or alcohol (86.1-87.5%) than the non-chewers (50.6-56.7%). The overall prevalence of OSF was 1.0%. Compared with the subjects without OSF (1.7-23.2%), a significantly higher proportion of OSF patients were a current-chewer (62.3% in men and 100.0% in women).

CONCLUSIONS

BQ chewing is a vital risk factor for OSF in Hunan. A high prevalence of BQ chewing found among the younger cohort (15-49 years old) is an urgent warning for this oral premalignant disorder.

Cyclooxygenase-2 ( COX -2) gene-765G/C polymorphism and advanced-stage endometriosis in Korean women

PROBLEM

We investigated the association of COX -2 gene-765G/C polymorphism and risk of advanced-stage endometriosis in Korean women.

METHOD OF STUDY

This study consisted of 268 women with advanced-stage endometriosis and 242 control women without endometriosis in Korea. Subjects were genotyped for the -765G/C polymorphism of the COX -2 gene by RFLP-PCR analysis.

RESULTS

There were significant differences in the genotype distributions of the -765G/C polymorphism between patients with advanced-stage endometriosis and control subjects. The C allele for -765G/C was associated with significantly lower risk of advanced-stage endometriosis (OR, 0.14; 95% CI, 0.06-0.30).

CONCLUSIONS

We have demonstrated a significant genetic association between the -765G/C polymorphism and advanced-stage endometriosis in Korean women. The -765C allele may be protective against the development of the disease in Korean women.

Determination of arecoline in areca nut based on field amplification in capillary electrophoresis coupled with electrochemiluminescence detection

A sensitive capillary electrophoresis-electrochemiluminescence (CE-ECL) assay with an ionic liquid (IL) was developed for the determination of arecoline in areca nut. The IL, 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF(4) ), was an effective additive improved not only the separation selectivity but also the detection sensitivity of the analyte. BMImBF(4) in the separation electrolyte made the resistance of the separation buffer much lower than that of the sample solution, which resulted in an enhanced field amplified electrokinetic injection CE. ECL intensity of arecoline is about two times higher than that of the analyte with phosphate-IL buffer system. Resolution between arecoline and other unknown compounds in real samples was improved. Under the optimized conditions (ECL detection at 1.2 V, 16 kV separation voltage, 20 mmol/L phosphate with 10 mmol/L BMImBF(4) buffer at pH 7.50, 5 mmol/L Ru(bpy)(3)(2+) and 50 mmol/L phosphate buffer in the detection reservoir), a detection limit of 5 × 10(-9) mol/L for arecoline was obtained. Relative standard deviations of the ECL intensity and the migration time were 4.51% and 0.72% for arecoline. This method was successfully applied to determination of the amount of arecoline in areca nut within 450 s.

Population burden of betel quid abuse and its relation to oral premalignant disorders in South, Southeast, and East Asia: an Asian Betel-quid Consortium Study

OBJECTIVES

We investigated the population burden of betel quid abuse and its related impact on oral premalignant disorders (OPDs) in South, Southeast, and East Asia.

METHODS

The Asian Betel-Quid Consortium conducted a multistage sampling of 8922 representative participants from Taiwan, Mainland China, Malaysia, Indonesia, Nepal, and Sri Lanka. Participants received an interviewer-administered survey and were examined for oral mucosal disorders.

RESULTS

The prevalence of betel quid abuse was 0.8% to 46.3% across 6 Asian populations. The abuse frequency was over 40.5% for current chewers, with the highest proportion in Nepalese and Southeast Asian chewers (76.9%-99.6%). Tobacco-added betel quid conferred higher abuse rates (74.4%-99.6%) among Malaysian, Indonesian, and Sri Lankan men than did tobacco-free betel quid (21.8%-89.1%). Gender, lower education level, younger age at chewing initiation, and clustering of familial betel quid use significantly contributed to higher abuse rates. Indonesian betel quid abusers showed the highest prevalence of OPDs and had a greater risk of OPDs than did nonabusers.

CONCLUSIONS

Betel quid abuse is high in regions of Asia where it is customarily practiced, and such abuse correlates highly with OPDs. By recognizing abuse-associated factors, health policies and preventive frameworks can be effectively constructed to combat these oral preneoplasms.

Role of cyclooxygenase-2 gene polymorphisms in pancreatic carcinogenesis

AIM: To evaluate the clinical significance of -765G/C and -1195G/A cyclooxygenase-2 (COX-2) gene polymorphisms in patients with pancreatic cancer (PC).

METHODS: The study included 201 patients: 85 with PC and 116 healthy controls. -765G/C and -1195G/A COX-2 gene polymorphisms were studied in DNA isolated from blood samples. The associations of the analyzed genotypes and clinical data at diagnosis were evaluated.

RESULTS: We found an increased frequency of the homozygous -1195AA COX-2 genotype in patients with PC (53.7%) compared with the control group (21%) (P < 0.01). In contrast, the distribution of genotype and allele frequencies of the -765G/C COX-2 polymorphism in the PC patients were not different from those in control groups. A correlation between presence of homozygous -1195AA COX-2 genotype and tumor size > 3 cm was observed (P < 0.05). Analyzed polymorphisms were unrelated to the patients’ sex and age, nor to the presence of regional or distant metastases.

CONCLUSION: These preliminary results indicate that the -1195G/A COX-2 polymorphism may play an important role in PC prognosis and carcinogenesis.

The Cox-2 -1195 G > A polymorphism and cancer risk: a meta-analysis of 25 case-control studies

Cyclooxygenase 2 (Cox-2, a rate-limiting enzyme in the conversion of arachidonic acid to prostanoids) has been implicated in several physiological and pathological processes, and it has been reported that polymorphisms in the regulatory region of Cox-2 might influence its expression, contributing to the interindividual susceptibility to cancer. However, results from published studies on the association between the Cox-2 -1195G > A polymorphism and the risk of cancer are conflicting. We performed a meta-analysis based on 25 case-control studies, including a total of 9482 cancer cases and 12 206 controls to derive a more precise estimation of the association and its possible influence on cancer risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. The overall results indicated that the variant genotypes moderately increased risk of cancer (AA/AG versus GG, OR = 1.15, 95% CI: 1.02-1.31). In the stratified analysis for the -1195G > A polymorphism, a proximate association was observed in Asian populations (AA/AG versus GG, OR = 1.28, 95% CI: 1.12-1.46), but no significant association except for oesophageal cancer and 'others' was found when stratified by cancer type. In conclusion, our meta-analysis indicates that -1195G > A of Cox-2 is a low penetration risk factor for cancer.

CYP26B1 is a novel candidate gene for betel quid-related oral squamous cell carcinoma

Substantial epidemiological data suggest a role for environmental factors (for example, the use of alcohol, betel quid (BQ), and cigarettes) in the occurrence of oral squamous cell carcinoma (OSCC), but the evidence for the genes involved has been inconsistent. This study was to investigate the role of CYP26B1, together with the use of alcohol, BQ, and cigarettes, on BQ-related OSCC. The association study (247 OSCC cases and 338 controls) was conducted to examine the possible interplay between CYP26B1 polymorphisms and alcohol, BQ, and cigarettes use. Additional gene expression was evaluated between OSCC tissue and adjacent normal tissue. The genetic polymorphism AA of CYP26B1 appeared to correlate with the risk of OSCC (OR=2.26; 95% CI, 1.35-3.80). Chewing BQ multiplicatively interacted with CYP26B1 AA to increase the OSCC risk (aOR=70.04; 95% CI, 13.62-360.11). The independent risk of OSCC was observed among BQ chewers with CYP26B1 AA, and compared with chewers with the CYP26B1 CC genotype (stratified aOR=2.88; 95% CI, 1.07-7.74). Increased expression of CYP26B1 was observed in tumor tissue compared with adjacent normal tissue. The CYP26B1 gene plays a novel role in the BQ dependent pathogenesis of OSCC.

Bronchial epithelium-derived IL-8 and RANTES increased bronchial smooth muscle cell migration and proliferation by Krüppel-like factor 5 in areca nut-mediated airway remodeling

This study is first to analyze the inflammatory cytokines, produced by the bronchial epithelium after exposure to areca nut extract (ANE), which contribute to airway remodeling by increasing human bronchial smooth muscle cells (BSMC) migration and proliferation. We treated human bronchial epithelial cell lines BEAS-2B and HBE135-E6E7 (HBE) with ANE, saliva-reacted ANE (sANE), and the areca alkaloids arecoline and then harvested the conditioned medium (CM) that was added to BSMC. Exposure of BEAS-2B and HBE to ANE, sANE, and arecoline increased interleukin 8 (IL-8) and Regulated upon Activation, Normal T-cell Expressed, and Secreted (RANTES) production. Cultures of BSMC with ANE-, sANE-, and arecoline-BEAS-2B-CM and -HBE-CM increased BSMC proliferation and migration. Induction of BSMC proliferation and migration by sANE-BEAS-2B-CM and -HBE-CM was associated with increased phosphorylation of Raf, MEK1/2, and extracellular signal regulated kinase (ERK)1/2 and the upregulation of krüppel-like factor 5 (KLF5), cyclin D, and integrin-linked kinase. Blocking ERK1/2 by a specific inhibitor significantly decreased BSMC proliferation and migration by inhibiting KLF5 enhancement. KLF5 knockdown also decreased sANE-BEAS-2B-CM, sANE-HBE-CM, and recombinant human interleukin 8/recombinant human RANTES-mediated BSMC proliferation and migration, suggesting that KLF5 was involved in the regulation of BSMC proliferation and migration. Our study suggests that inhibition of IL-8 and RANTES or IL-8/RANTES-mediated mitogen-activated protein kinase/KLF5 signaling is an attractive therapeutic target for areca nut-induced asthma.