Association of the A870G cyclin D1 gene polymorphism with genetic susceptibility to nasopharyngeal carcinoma

SSTR2 in Nasopharyngeal Carcinoma: Relationship with Latent EBV Infection and Potential as a Therapeutic Target

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor, most commonly located in the pharyngeal recess and endemic to parts of Asia. It is often detected at a late stage which is associated with poor prognosis (5-year survival rate of 63%). Treatment for this malignancy relies predominantly on radiotherapy and/or systemic chemotherapy, which can be associated with significant morbidity and impaired quality of life. In endemic regions NPC is associated with infection by Epstein-Barr virus (EBV) which was shown to upregulate the somatostatin receptor 2 (SSTR2) cell surface receptor. With recent advances in molecular techniques allowing for an improved understanding of the molecular aetiology of this disease and its relation to SSTR2 expression, we provide a comprehensive and up-to-date overview of this disease and highlight the emergence of SSTR2 as a key tumor biomarker and promising target for imaging and therapy.

AA genotype of cyclin D1 G870A polymorphism increases breast cancer risk: Findings of a case-control study and meta-analysis

BACKGROUND

Cyclin D1 (CCND1) polymorphisms, a regulator of the cell cycle progress from G1 to the S phase, may lead to uncontrolled cell proliferation and lack of apoptosis. G870A, a common single-nucleotide polymorphism in CCND1 influences breast cancer risk. However, the association between G870A polymorphism and breast cancer risk is ambiguous so far.

MATERIALS AND METHODS

In this case-control study, we analyzed the role of G870A polymorphism with breast cancer risk in Indian women. A meta-analysis of 18 studies was also performed to elucidate this association by increasing statistical power.

RESULTS

In our case-control study, significant risk association of the CCND1 G870A AA genotype with breast cancer in total cohort (odds ratio [OR], 2.98; 95% confidence interval [CI], 1.64-5.42; P value, 4.96e-04) and premenopausal women (OR, 3.31; 95% CI, 1.54-7.08; P value, .003) was found. The results of the meta-analysis showed that AA genotype of the CCND1 G870A polymorphism significantly increases breast cancer risk in total pooled data (AA vs GG+GA: OR = 1.20; 95% CI = 1.03 to 1.39; P value, 0.016*) and Caucasian (AA vs GG+GA: OR = 1.22; 95% CI = 0.99 to 1.51; P value, .056*) but not in Asian population. Further, a significant protective association with breast cancer was also found in the GA vs AA comparison model in pooled data (OR = 0.73; 95% CI = 0.58 to 0.92; P value, .007*) as well as in Caucasian subgroup (OR = 0.62; 95% CI = 0.49 to 0.94; P value, .022*).

CONCLUSION

CCND1 G870A AA genotype was found associated with breast cancer risk. Future association studies considering the environmental impact on gene expression are required to validate/explore this association.

The association between COX-2 gene rs5275 polymorphism and Nasopharyngeal carcinoma risk

The overexpression of cyclooxygenase-2 (COX-2) was correlated with the invasion and lymphatic metastasis and with the clinical stage of Nasopharyngeal carcinoma (NPC). The C allele of COX-2 gene rs5275 polymorphism disrupts miR-542-3p function to promote COX-2 overexpression. To examine the role of COX-2 gene rs5275 polymorphism in NPC, we determined COX-2 gene rs5275 polymorphism by using a custom-by-design 48-Plex single nucleotide polymorphism (SNP) Scan^™ Kit. We found that C allele or CC genotype of rs5275 polymorphism in COX-2 gene was associated with an increased risk of NPC. In stratified analyses, COX-2 gene rs5275 polymorphism was associated with the risk of NPC among females, smokers, and drinkers. Based on these results, we concluded that COX-2 gene rs5275 variant contributes to NPC risk in a Chinese population. Larger studies with more diverse ethnic populations are needed to confirm these results.

Functional role of CyclinD1 polymorphism (G870A) in modifying susceptibility and overall survival of North Indian lung cancer patients

PURPOSE

The purpose of this study was to investigate the potential role of the cyclin D1 gene G870A polymorphism in the likelihood of the development of lung cancer and the overall survival of lung cancer patients in the North Indian population.

METHODS

The study consisted of 353 lung cancer cases and 351 age- and gender-matched healthy controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPP) was done for the CCND1 gene. The association analysis was done using the multiple linear regression, and the survival analysis was done using the Kaplan-Meier and the Cox regression models.

RESULTS

The GA genotype was associated with an increased risk for overall lung cancer (odds ratio [OR] = 1.63; p = 0.01). Combined variant genotype showed a significant association for overall lung cancer (OR 1.50; p = 0.03). In addition, smokers with the carrier genotype of CCND1 were found to have a significantly higher risk for lung cancer (OR 1.57; p = 0.04). No significant correlation was observed between the overall survival of lung cancer patients and CCND1 polymorphism. However, on stratifying the subjects on the basis of histology, it was evident that small-cell lung cancer (SCLC) patients carrying the mutant (AA) genotype showed nearly a fivefold increased mortality rate compared to the wild (GG) genotype (p = 0.03).

CONCLUSIONS

Our results suggest that polymorphic CCND1 may increase the risk of lung cancer in smokers from North India, and it may be associated with the overall survival of SCLC patients.

Functional Role of CyclinD1 Polymorphism (G870A) in Modifying Susceptibility and Overall Survival of North Indian Lung Cancer Patients

Purpose The purpose of this study was to investigate the potential role of the cyclin D1 gene G870A polymorphism in the likelihood of the development of lung cancer and the overall survival of lung cancer patients in the North Indian population. Methods The study consisted of 353 lung cancer cases and 351 age- and gender-matched healthy controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPP) was done for the CCND1 gene. The association analysis was done using the multiple linear regression, and the survival analysis was done using the Kaplan-Meier and the Cox regression models. Results The GA genotype was associated with an increased risk for overall lung cancer (odds ratio [OR] = 1.63; p = 0.01). Combined variant genotype showed a significant association for overall lung cancer (OR 1.50; p = 0.03). In addition, smokers with the carrier genotype of CCND1 were found to have a significantly higher risk for lung cancer (OR 1.57; p = 0.04). No significant correlation was observed between the overall survival of lung cancer patients and CCND1 polymorphism. However, on stratifying the subjects on the basis of histology, it was evident that small-cell lung cancer (SCLC) patients carrying the mutant (AA) genotype showed nearly a fivefold increased mortality rate compared to the wild (GG) genotype (p = 0.03). Conclusions Our results suggest that polymorphic CCND1 may increase the risk of lung cancer in smokers from North India, and it may be associated with the overall survival of SCLC patients.

5'UTR +24T>C CR2 is not associated with nasopharyngeal carcinoma development in the North Region of Portugal

OBJECTIVE

We have analysed the association of the +24T>C polymorphism (rs3813946) in CR2, the cellular receptor for Epstein-Barr virus (EBV), in the susceptibility for the development of nasopharyngeal carcinoma (NPC).

METHODS

A retrospective case-control study was developed with peripheral blood samples from 111 individuals with NPC and 608 healthy individuals (controls) from the North region of Portugal. The genotyping analysis was performed by allelic discrimination real-time PCR using a TaqMan(®) SNP Genotyping Assay.

RESULTS

The genotype distribution was 62.2% TT, 34.2% TC and 3.6% CC for NPC patients; and 65.0%, 30.6% and 4.4%, respectively, for controls. Our study showed no statistical association between the genotype distribution in controls and all types of NPC (P = 0.717); nevertheless, the analysis showed statistically significant differences (P = 0.038) regarding cases with well- or moderately differentiated types of NPC suggesting that +24CC/CT genotypes are associated with increased risk (OR = 4.16; 95% CI 1.28-15.7; P = 0.016).

CONCLUSIONS

This is the first study in Western populations to characterize the association of the CR2 +24T>C polymorphism in NPC development, and our results suggest that more studies are required to clarify the impact on NPC susceptibility in different populations.

Association of cyclin D1 variants with head and neck cancer susceptibility: evidence from a meta-analysis

Whether cyclin D1 (CCND1) gene variants increase susceptibility to head and neck cancer (HNC) is undetermined. Therefore, we performed the present meta-analysis to systematically assess any possible association between CCND1 variants (G870A and G1722C) and HNC risk. Seventeen studies for CCND1 G870A and three studies for CCND1 G1722C were included. Overall, CCND1 polymorphisms (G870A and G1722C) had no association with increased HNC risk (p>0.05). In the subgroup analysis by smoking status, significantly increased HNC risk was found among smokers under allele contrast, homozygous comparison and recessive models (p<0.05), smoking carriers of A allele and AA genotype appearing at elevated risk. In conclusion, while there was overall a lack of any association between CCND1 polymorphisms (G870A and G1722C) and HNC risk, smokers carrying the A allele and AA genotype of the CCND1 G870A polymorphism may be susceptible to HNC development.

Cyclin D1 G870A polymorphism and risk of nasopharyngeal carcinoma: a case-control study and meta-analysis

Background

Cyclin D1 (CCND1) plays a key role in cell cycle regulation. It is a well-established human oncogene which is frequently amplified or overexpressed in cancers. The association between CCND1 G870A polymorphism and cancer risk has been widely assessed. However, a definitive conclusion between CCND1 G870A polymorphism and risk of nasopharyngeal carcinoma (NPC) remains elusive.

Methods

We firstly performed a hospital-based case-control study involving 165 NPC cases and 191 cancer-free controls in central-south China, and then conducted a meta-analysis with six case-control studies to evaluate the association between NPC risk and CCND1 G870A polymorphism.

Results

The case-control study found a significant association between CCND1 G870A polymorphism and NPC risk in various comparison models (AA vs. GG: OR = 2.300, 95% CI 1.089–4.857, p = 0.029; AG vs. GG: OR = 2.832, 95% CI 1.367–5.867, p = 0.005; AA/AG vs. GG: OR = 2.597, 95% CI 1.288–5.237, p = 0.008; AA vs. AG/GG: OR = 0.984, 95% CI 0.638–1.518, p = 0.944). Further meta-analysis showed that there was no significant association between CCND1 G870A polymorphism and NPC risk in overall analysis. In the stratified analysis by race, however, significant associations were only found in Caucasians (for the allele model A vs. G: OR = 0.75, 95% CI 0.59–0.97, p = 0.03; for the co-dominant model AA vs. GG: OR = 0.52, 95% CI 0.32–0.86, p = 0.01; for the dominant model AA/AG vs. GG: OR = 0.49, 95% CI 0.32–0.74, p<0.01; for the recessive model AA vs. AG/GG: OR = 0.90, 95% CI 0.61–1.34, p = 0.60).

Conclusions

A significant association between CCND1 G870A polymorphism and NPC risk was found in the central-southern Chinese population. The meta-analysis indicated that CCND1 G870A polymorphism may contribute to the development of NPC in Caucasians.

Etiological factors of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common disease among southern Chinese. The major etiological factors proposed for NPC pathogenesis include genetic susceptibility, environment factors and EBV infection. In the high risk population, genetic susceptibility to NPC has been mapped to the HLA loci and adjacent genes in MHC region on chromosome 6p21. Consumption of preserved food including salted fish has been implicated in its etiology in earlier studies. Its contribution to pathogenesis of NPC remains to be determined. A decreasing trend of NPC incidence was observed in Hong Kong, Taiwan and Singapore in recent years which may be accounted by a change of dietary habits. A comprehensive epidemiological study will help to elucidate the relative importance of various risk factors in the pathogenesis of NPC. Despite the close association of EBV infection with NPC, the etiological role of EBV in NPC pathogenesis remains enigmatic. EBV infection in primary nasopharyngeal epithelial cells is uncommon and difficult to achieve. EBV does not transform primary nasopharyngeal epithelial cells into proliferative clones, which contrasts greatly with the well-documented ability of EBV to transform and immortalize primary B cells. Genetic alterations identified in premalignant nasopharyngeal epithelium may play crucial roles to support stable EBV infection. Subsequently, latent and lytic EBV gene products may drive clonal expansion and transformation of premalignant nasopharyngeal epithelial cells into cancer cells. Stromal inflammation in nasopharyngeal mucosa is believed to play an important role in modulating the growth and possibly drive the malignant transformation of EBV-infected nasopharyngeal epithelial cells. Furthermore, there are increasing evidences supporting a role of EBV infection to evade host immune surveillance. EBV-infected cells may have selective growth advantages in vivo by acquiring a stress-resistance phenotype. Understanding the etiological factors and pathogenesis of NPC will contribute effectively to the prevention and treatment of this disease.

Cyclin D1 G870A polymorphism and risk of nasopharyngeal carcinoma: a meta-analysis

Recently, there have been a number of studies on the association between cyclin D1 G870A polymorphism and nasopharyngeal carcinoma risk. However, the results of previous reports remain controversial and ambiguous. Thus, we performed a meta-analysis to explore more precisely the association between cyclin D1 G870A polymorphism and the risk of nasopharyngeal carcinoma. No significant association was found between cyclin D1 G870A polymorphism and nasopharyngeal carcinoma risk in total population analysis. In the subgroup meta-analysis by ethnicity, a negative association was shown in Caucasian subgroup, and no significant association in any genetic models among Asians was observed. In summary, positive results have been shown on the search for polymorphic variants influencing the risk of NPC. This meta-analysis provides evidence of the association between CCND1 G870A polymorphism and NPC risk, supporting the hypothesis that CCND1 870A allele probably acts as an important NPC protective factor in Caucasians but not in Asians. Since the results of our meta-analysis are preliminary and may be biased by the relatively small number of subjects, they still need to be validated by well-designed studies using larger samples in the future.

IL-1RN VNTR polymorphism as a susceptibility marker for nasopharyngeal carcinoma in Portugal

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a rare malignancy in Western countries that is widely associated with the infection by Epstein-Barr virus (EBV). Several studies have showed that a common allele (allele 2) of the 86-bp variable number of tandem repeats (VNTR) polymorphism within intron 2 of the interleukin 1 receptor antagonist (IL-1RN) gene is associated with several disorders, including viral-associated cancers.

METHODS

We have developed a hospital-based case-control study to characterise the role of the IL-1RN 86-bp VNTR polymorphism in the development of NPC with 112 patients with the disease and 433 healthy individuals from the northern region of Portugal. IL-1RN genotypes were combined according to the number of repeats: allele 2 (A2), the short allele that corresponds to two repeats, and L, the long allele that corresponds to three or more repeats.

RESULTS

Our study revealed that 31.2% of NPC patients were IL-1RN A2*A2, compared with 9.7% observed in the control group. The statistical analysis revealed that IL-1RN*A2 homozygosity for the A2 allele was associated with a fourfold increased risk for NPC development (p<0.001). Additionally, cumulative hazard analysis revealed that estimated median age of onset of NPC is significantly (p<0.001) different for A2*A2 homozygous versus non-A2*A2 (57.0 vs. 74.0, respectively).

CONCLUSIONS

This is the first study to evaluate the role of the IL-1RN VNTR in NPC development in Portugal. Our study indicates IL-1RN*A2 homozygosity as a significant risk marker in our population and that it should be further investigated for the potential role in the definition of a susceptibility profile for NPC onset.

Role of the MDM2 SNP309 polymorphism in the initiation and early age of onset of nasopharyngeal carcinoma

Recent studies refer that amplification/overexpression of the principal negative regulator of p53 (Mdm2) is frequently found in several malignancies. Several studies have associated a polymorphism (SNP309 T/G) in the promoter region of MDM2 with higher levels of this protein, which will favor p53-pathway abolishment, cell-cycle escape, and development of cancer. We aimed to study if MDM2 SNP309 T/G polymorphism contributes to the development of nasopharyngeal carcinoma (NPC). We have developed a case-control study with 124 patients with NPC and 509 healthy individuals from the north of Portugal to determine the genetic distribution of the MDM2 SNP309 polymorphism in DNA extracted from peripheral blood samples. Statistical analysis was performed to compare categorical variables adjusted for age and gender by multivariate logistic regression. Genotype-specific distributions according to age of onset were tested by Kaplan-Meier method and analyzed by Cox-regression proportional hazard model adjusted for gender. This study revealed that MDM2 SNP309 GG homozygous represent an increased risk adjusted for age and gender to develop NPC (OR = 2.15), with particular effect in undifferentiated types (OR = 2.46) and early clinical stages (OR = 3.32). We also found that median age of onset of NPC was significantly different (55.2 vs. 61.6) with increased effect in undifferentiated types (55.2 vs. 61.9) and early clinical stages (55.3 vs. 65.3). Our study suggests that MDM2 SNP309 can be considered a risk marker for the development of NPC mainly in early ages probably as an initiation marker for potential cancer development.

The progress on genetic analysis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world, but is one of the most common cancers in Southeast Asia. Both genetic and environmental factors contribute to the tumorigenesis of NPC, most notably the consumption of certain salted food items and Epstein-Barr virus infection. This review will focus on the current progress of the genetic analysis of NPC (genetic susceptibilities and somatic alterations). We will review the current advances in genomic technologies and their shaping of the future direction of NPC research.

Nasopharyngeal carcinoma in a south European population: epidemiological data and clinical aspects in Portugal

The incidence of nasopharyngeal carcinoma (NPC) varies worldwide, with higher rates in southern Asia, intermediate rates in Mediterranean basin countries as well as in Greenland and Alaska populations, and low rates in most of the western countries. The percentage of NPC types seems to vary according to the WHO classification. Portugal is also a Mediterranean basin country. The NPC patterns in Portuguese population is comparatively analyzed with a review of the related literature, concerning the overall incidence, male/female ratio, age of incidence, WHO type frequency, Epstein-Barr virus relationship and genetic susceptibility. The particular findings in the Portuguese population can be discussed in the light of genetic background and close relationships with potential exogenous oncogenic factors.

No association between epidermal growth factor and epidermal growth factor receptor polymorphisms and nasopharyngeal carcinoma

Numerous candidate genes have been proposed as susceptibility factors for the development of nasopharyngeal carcinoma (NPC). Epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) interaction plays a pivotal role in cell proliferation, differentiation, and tumourigenesis of epithelial tissues. To our knowledge, however, no study has examined the relationship between the EGF/EGFR and NPC. The aim of this study is to investigate the potential association between single-nucleotide polymorphisms of EGF +61 G/A and EGFR +2073 A/T and NPC. A total of 173 patients with NPC and 206 age- and sex-matched controls were the participants. Genotypes were determined using a polymerase chain reaction-restriction fragment length polymorphism strategy and DNA sequencing. There were no significant differences in the genotype and allele frequencies of EGF +61 G/A and EGFR +2073 A/T polymorphisms between the group of patients with NPC and the control group in a Chinese population (for EGF +61 G/A: OR=1.29, 95% CI: 0.95-1.74; for EGFR +2073 A/T: OR=0.91, 95% CI: 0.67-1.23). Further studies are still needed to explore the complicated interaction between environmental factors and EGF +61 G/A and EGFR +2073 A/T polymorphisms in the risk of NPC, particularly in ethnically different populations.

Oncogenic virus-associated neoplasia: a role for cyclin D1 genotypes influencing the age of onset of disease?

Cyclin D1 (CCND1) is a key regulatory protein at the G1/S checkpoint of the cell cycle. The purpose of our study was to assess the role of CCND1 genotypes influencing the age of onset of oncogenic virus-associated neoplasia. We conducted a hospital-based case-control study of 581 individuals, including 247 controls and 334 cases (108 nasopharyngeal and 226 cervical cancer cases). The polymorphism analysis was performed in blood samples by PCR-RFLP methodology. Age-adjusted logistic regression analysis indicates that individuals carrying two G-alleles have an increased genetic susceptibility for the development of oncogenic virus-associated cancers (aOR=2.02, 95% CI 1.30-3.14, P=0.002). Moreover, our results indicate that the waiting time for onset of oncogenic virus-associated neoplasia in patients homozygous (GG) for CCND1 genotypes (52 years) was 12 years earlier in comparison with patients carrying AG or AA genotypes (60 years) (log-rank test: P=0.0003). Our results may be important in contributing to a more extensive knowledge of the mechanisms involved in oncogenic virus-associated carcinogenesis, as CCND1 may be an important target for the development of new strategies for cancer treatment and prevention.

Association of familial colorectal cancer with variants in the E-cadherin (CDH1) and cyclin D1 (CCND1) genes

INTRODUCTION

About 20% of colorectal cancer (CRC) patients show some kind of familiarity, which might be caused by yet unknown combinations of low penetrance susceptibility genes. We aimed to identify genetic factors for familial CRC (fCRC) in a unique study design that includes phenotypic extremes as represented by fCRC cases and 'hyper-normal' controls without CRC history and no adenomatous polyps on colonoscopy.

MATERIALS AND METHODS

Candidate gene variants were determined by allele-specific amplification (SLC10A2 c.169C>T and c.171G>T) and restriction fragment length polymorphism assays (CCND1 c.870A>G; CDH1 -160C>A; TP53 R72P; VDR T2M). In total, 98 patients with fCRC, 96 patients with sporadic CRC, and 220 hyper-normal controls were included.

RESULTS

The minor allele of the CDH1 -160C>A polymorphism occurred significantly more often in controls compared to fCRC cases (OR = 0.664; p = 0.042). Homozygosity of the minor allele was significantly associated with affiliation to the control group (OR = 0.577; p = 0.029), indicating that both heterozygous and homozygous carriers of the common allele are at-risk for CRC. With respect to the CCND1 c.870A>G mutation, comparison of fCRC and sporadic CRC cases showed that A/A homozygosity was more common than G/G homozygosity among fCRC patients compared to controls (OR = 2.119; p = 0.045). However, no differences in allele or genotype frequencies were detected between sporadic CRC cases and controls, and no associations were observed for SLC10A2, TP53, and VDR polymorphisms.

CONCLUSIONS

We report a potential association of variants in the CCND1 and CDH1 genes with fCRC using a unique study design with phenotypic extremes.

Interleukin-10 gene promoter polymorphisms and the risk of nasopharyngeal carcinoma

Genetic factors are known to be important in the development of nasopharyngeal carcinoma (NPC). Interleukin-10 (IL-10) is an immunosuppressive cytokine which may facilitate development of cancer by supporting tumor escape from the immune response. Interindividual variations in IL-10 production were genetically contributed to polymorphisms within IL-10 promoter region. The aim of this study was to determine whether single nucleotide polymorphisms (SNPs) at positions -1082 (A/G), -819 (T/C) and -592 (A/C) in the IL-10 gene promoter were involved in predisposing an individual to NPC. One hundred and ninety-eight patients with NPC and 210 age- and sex-matched controls, genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism. There were significantly differences in the genotype and allele distribution of -1082 A/G polymorphism of the IL-10 gene among cases and controls. The -1082 AG and GG genotypes were associated with a significantly increased risk of NPC as compared with the -1082 AA genotypes. Haplotype analysis showed that the homozygosity of the GCC haplotype (defined by SNPs at positions -1082, -819 and -592) of IL-10 gene conveys the highest risk for NPC compared with the homozygosity for the ATA haplotype. This study shows for the first time an association between IL-10 gene promoter -1082 A/G polymorphism and its haplotype may contribute to genetic susceptibility to NPC in a Chinese population.

Single nucleotide polymorphism and haplotype association of the interleukin-8 gene with nasopharyngeal carcinoma

The cytokine interleukin-8 (IL-8) may play a role in the pathogenesis of nasopharyngeal carcinoma (NPC) through the modulation of tumor immune response or enhanced angiogenesis. Polymorphism of IL-8 gene, which may affect the production level of cytokine, has been inversely associated with a number of cancers. To test this hypothesis, we investigated the relationship of IL-8 gene polymorphisms and NPC in a Chinese population. We analyzed single nucleotide polymorphisms (SNPs) of IL-8 gene -845 T/C, -738 T/A, -353 A/T, -251 A/T and +678 T/C in 280 patients with NPC and 290 age and sex matched controls, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and polymerase chain reaction-sequence specific primers method (PCR-SSP). There were significant differences in the genotype and allele distribution of -251 A/T polymorphism of the IL-8 gene among cases and controls. The -251 AA and AT genotypes were associated with a significantly increased risk of NPC as compared with the -251 TT genotypes (OR=1.820, 95% CI, 1.120-2.959, P=0.015 and OR=1.590, 95% CI, 1.104-2.290, P=0.013, respectively). Haplotype analysis revealed that the homozygosity of the AAT haplotype (defined by SNPs at positions -353, -251 and +678) of IL-8 gene conveys the highest risk for NPC compared with the homozygosity for the TTC haplotype (OR=1.396; 95% CI, 1.064-1.831; P=0.016). The -251 A/T polymorphism of IL-8 and its haplotype are associated with NPC in a Chinese population. Our data suggests that IL-8 gene may play a role in the development of NPC.

Nasopharyngeal carcinoma: molecular biomarker discovery and progress

Nasopharyngeal carcinoma (NPC) is a rare malignancy in most part of the world and it is one of the most confusing, commonly misdiagnosed and poorly understood diseases. The cancer is an Epstein-Barr virus-associated malignancy with a remarkable racial and geographical distribution. It is highly prevalent in southern Asia where the disease occurs at a prevalence about a 100-fold higher compared with other populations not at risk. The etiology of NPC is thought to be associated with a complex interaction of genetic, viral, environmental and dietary factors. Thanks to the advancements in genomics, proteomics and bioinformatics in recent decades, more understanding of the disease etiology, carcinogenesis and progression has been gained. Research into these components may unravel the pathways in NPC development and potentially decipher the molecular characteristics of the malignancy. In the era of molecular medicine, specific treatment to the potential target using technologies such as immunotherapy and RNAi becomes formulating from bench to bedside application and thus makes molecular biomarker discovery more meaningful for NPC management. In this article, the latest molecular biomarker discovery and progress in NPC is reviewed with respect to the diagnosis, monitoring, treatment and prognostication of the disease.