Effects of Tobacco Habits on the Polymorphism of NFKB1 and NFKB1A Gene of Head and Neck Squamous Cell Carcinoma in Indian Population

Background: Polymorphism of NFKB1 and NFKB1A are highly associated with cancer. We have assessed polymorphism in the promoter region of NFKB1 -94 del/ins ATTG (rs28362491) and NFKB1A -826 C/T (rs2233406) with the risk of HNSCC in Indian population. Methods: Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) method was used for the genotyping NFKB1 -94 del/ins ATTG and NFKB1A -826 C/T. Sequencing was done to validate the results of PCR-RFLP. Statistical analysis of data was done by Stata/SE-14.0 software. Results: ins/ins genotype was observed to be a risk factor of HNSCC as compared del/del genotype of NFKB1 -94 ATTG. Interactive effects of smoking and chewing on ins/ins genotype showed 13.96 and 10.92 fold increased risk of HNSCC. NFKB1A -826 C/T polymorphism, TT genotype showed no association with the risk of HNSCC as compared to wild type CC genotype. Conclusion: Our results showed NFKB1 -94 del/ins ATTG with smoking and tobacco chewing may increase the risk of HNSCC while NFKB1A -826 C/T plays a protective role in Indian population.     

A functional insertion/deletion polymorphism in the promoter region of NFKB1 gene increases susceptibility for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common malignancy in southern China and Southeast Asia. Nuclear factor-κB (NF-κB)-activation plays critical roles in Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) mediated tumorigenesis in NPC. A functional insertion/deletion polymorphism (−94 insertion/deletion ATTG) in the promoter of NFKB1 gene, which encodes the p50 subunit of NF-κB protein complex, was recently identified. This study found that the frequency of ATTG₂ allele in NPC patients was significantly higher than that in control subjects (66% vs. 57.1%, p = 0.015, OR = 1.453), suggesting that the functional NFKB1 promoter polymorphism is associated with increased risk for NPC.     

CASP8 variants D302H and -652 6N ins/del do not influence the risk of colorectal cancer in the United Kingdom population

Polymorphisms in CASP8 at 2q33.1 have been associated with the risk of developing cancer, specifically, the D302H variant (rs1045485) with breast cancer in the European population and the -652 6N ins/del promoter variant (rs3834129) with multiple tumours including colorectal cancer (CRC) in the Chinese population. We evaluated the relationship between -652 6N ins/del and D302H variants and risk of developing CRC in the UK population by genotyping 4016 cases and 3749 controls. Both variants showed no evidence of an association with risk of developing CRC (P=0.42 and 0.22, respectively). In contrast, the recently identified CRC susceptibility allele rs6983267 mapping to 8q24 was significantly associated with disease risk (P=8.94 x 10(-8)). It is thus very unlikely that variation in CASP8 defined by -652 6N ins/del or D302H influences the risk of CRC in European populations. The implications of our findings both in terms of population-specific effects and publication bias are discussed.     

Multilocus loss of heterozygosity allelotypes identify a genetic pathway associated with progression from low to high stage disease in neuroblastoma

Neuroblastoma is a heterogeneous tumour with a variety of clinical phenotypes, ranging from a localised tumour with excellent outcome (stage 1) to a metastatic, usually fatal malignancy (stage 4). In order to investigate the genetic relationship between these tumour subtypes, a loss of heterozygosity (LOH) analysis was carried out. Composite LOH allelotypes incorporating data from 96 loci on 5 chromosomes (1p, 3p, 4p, 11q, 14q), were constructed for 62 neuroblastomas. Neuroblastomas with similar allelotypes were clustered into groups and allelotype patterns correlated with clinical features. Three distinct genetic subgroups of neuroblastoma were observed. The largest group (50% of tumours) was characterised by specific allelotype patterns indicative of a stepwise accumulation of genetic alterations (11q LOH-->1p, 4p, and/or 14q LOH-->3p LOH), associated with progression from low to high stage disease. These tumours are distinct from MYCN amplified neuroblastomas which have a more rapid and aggressive disease course, and also a proportion of low stage tumours, often ganglioneuromas or ganglioneuroblastomas, with restricted growth potential.     

Efficacy of gemcitabine in patients with non-small cell lung cancer according to promoter polymorphisms of the ribonucleotide reductase M1 gene.

PURPOSE: High ribonucleotide reductase M1 (RRM1) expression in resected lung cancers has been associated with better clinical outcomes. However, gemcitabine-treated patients with high tumoral RRM1 expression generally evidence poor prognoses due to the decreased efficacy of gemcitabine therapy. This study was designed in accordance with the hypothesis that polymorphisms (-37 and -524) of the RRM1 promoter gene sequence, which regulate RRM1 expression, could influence the efficacy and prognosis of lung cancer patients treated with gemcitabine-based chemotherapy. EXPERIMENTAL DESIGN: A retrospective dataset of 97 patients with advanced non-small cell lung cancer treated with gemcitabine regimens as a first-line treatment was studied in this work. The allelotyping of RRM1 promoter polymorphisms was conducted via real-time PCR using genomic DNA obtained from peripheral WBC. RESULTS: The RRM1 promoter allelotype was RR37CC-R524TT in 58 patients, RR37AC-RR524CT in 29 patients, and other allelotypes in 10 patients. The response rate for gemcitabine-containing chemotherapy was 49.5%. The response rate was significantly higher in the RR37AC-RR524CT group (65.5%) compared with the group containing other allelotypes (42.6%; P = 0.039). Overall survival and progression-free survival did not differ significantly by allelotype. CONCLUSIONS: We detected significant differences in response rates to gemcitabine-based chemotherapy according to the allelotypes of the RRM1 promoter sequence, which could be determined using the germline DNA. Further functional and clinical studies will be required before this can be used as a predictive marker.     

Association between NFKB1 -94ins/delATTG promoter polymorphism and cancer risk: a meta-analysis

The aim of our meta-analysis was to assess the association between NFKB1 -94ins/delATTG promoter polymorphism and cancer risk. Eleven studies that included data from 2,743 cases and 2,195 controls were identified. When all groups were pooled, we did not detect the association between NFKB1 -94ins/delATTG promoter polymorphism and cancer risk. In the subgroup analysis, we detected the association of NFKB1 -94ins/delATTG promoter polymorphism with cancer in Caucasian population. The association also was found in Asian population. This meta-analysis demonstrates the association of NFKB1 -94ins/delATTG promoter polymorphism with cancer in Caucasian and Asian populations, and this association is ethno-specific.     

Is BRCA1-5083del19, identified in breast cancer patients of Sicilian origin, a Calabrian founder mutation?

Various studies have been published in Italy regarding the different BRCA1 mutations, but only the BRCA1-5083del19 mutation is recurrent and specific to individuals of Italian descent with a founder effect on the Calabrian population. In our previous study, BRCA1-5083del19 mutation carriers were found in four index cases of 106 Sicilian patients selected for familial and/or hereditary breast/ovarian cancers. The high frequency rate of this mutation identified in the Sicilian population led us to perform haplotype analysis in all family carriers. Five highly polymorphic microsatellite markers were used (D17S1320, D17S932, D17S1323, D17S1326, D17S1325) to establish whether or not all these families had a common ancestor. This analysis showed that all mutation carriers of these families had a common allele. None of the non-carriers of the mutation or of the 50 healthy Sicilian controls showed this haplotype. This allelotype analysis highlighted the presence of a common allele (ancestor), thus suggesting the presence of a founder effect in the Sicilian population. Our results are in contrast with other studies but only the allelotype analysis of all the BRCA1-5083del19 mutation carriers of two neighboring regions of the south of Italy (Calabria and Sicily) will make it possible to identify the real ancestor of this mutation. Antonio Russo and Valentina Calò have contributed equally to this work.     

A single nucleotide polymorphism in the matrix metalloproteinase-1 promoter enhances oral squamous cell carcinoma susceptibility in a Chinese population

We genotyped 96 oral squamous cell carcinoma (OSCC) patients for the 1G/2G polymorphism of matrix metalloproteinase-1 (MMP-1) promoter -1607 bp using PCR-RFLP. A control population of 120 frequency-matched subjects was also genotyped for the same polymorphism.The detection frequency of 2G allele was significantly higher in OSCC subjects (76%) than in the control group (56.7%). The frequency of 2G allele had a significant difference between the OSCC and controls group (p = 0.00, Odds Ratio, OR = 2.232, 95% CI = 1.477-3.372). The genotype 2G/2G was found in 57.3% of the OSCC, and 34.2% in the controls. The proportion of 2G homozygote (2G/2G) was significantly higher in the OSCC group when compared to controls (p = 0.001, OR = 2.585, 95% CI = 1.487-4.494). OSCC patients were stratified by clinicopathological parameters including gender, smoking, clinical stage and lymph node metastasis, but the only statistically significant association with MMP-1 genotype was with smoking. The results showed that a SNP in the MMP-1 promoter -1607 bp was associated with OSCC susceptibility in a Chinese population.     

Ribonucleotide reductase M1 gene promoter activity, polymorphisms, population frequencies, and clinical relevance

RRM1 is a gene crucial for determination of the tumor phenotype. It encodes the regulatory subunit of ribonucleotide reductase, and it is a molecular target of gemcitabine. In addition, RRM1 induces PTEN expression and inhibits cell migration, invasion, and metastasis formation. In patients with resected lung cancers, increased levels of RRM1 are highly associated with long survival. In contrast, patients on gemcitabine and cisplatin therapy for advanced disease have a poor survival if RRM1 expression is high presumably because of decreased efficacy of chemotherapy. We analyzed the RRM1 promoter for polymorphisms in an effort to develop a practical and inexpensive assay for RRM1 expression. Two single nucleotide polymorphisms, RR37 and RR524, were discovered. These polymorphisms impacted promoter activity in vitro and had different frequencies in various populations. Promoter allelotypes were highly associated with overall (P = 0.06) and disease-free (P = 0.03) patient survival. The allelotype with the highest predicted activity was associated with the best patient outcome. However, we did not find an association between allelotype and tumoral RRM1 expression. This is likely a result of the limited impact of the described promoter polymorphisms on overall in vivo gene expression. We conclude that clinical studies using RR37 and RR524 for decisions on chemotherapy are premature and that further functional studies on the RRM1 promoter are required to fully elucidate factors controlling RRM1 expression.     

Association between a functional insertion/deletion polymorphism in IL1A gene and risk of papillary thyroid carcinoma

The aim of this study was to evaluate whether an insertion/deletion polymorphism (rs3783553) locating in the miR-122 target gene IL1A 3′ untranslated region was related to the risk of papillary thyroid carcinoma (PTC). Genomic DNA was extracted from peripheral venous blood of 273 patients with PTC and 509 controls. The IL1A rs3783553 polymorphism was genotyped by using a polymerase chain reaction assay. No significant difference of the distribution of the IL1A rs3783553 polymorphism was observed between PTC patients and controls. However, patients carrying the IL1A rs3783553 ins/ins genotype and ins allele had significantly decreased risks for developing T3 and T4 when compared with patients carrying the IL1A rs3783553 del/del genotype and del allele (ins/ins vs. del/del: OR?=?0.22, 95 % confidence interval (CI), 0.09–0.54; ins vs. del: OR?=?0.58, 95 % CI, 0.41–0.83, respectively). These results suggest that the rs3783553 polymorphism may be used as a genetic marker to predict the size/extension of PTC.     

Increased risk of gastric cancer in Japanese subjects is associated with microsatellite polymorphisms in the heme oxygenase-1 and the inducible nitric oxide synthase gene promoters

Microsatellite polymorphism in the promoter region of the heme oxygenase-1 (HO-1) gene was analyzed jointly with that of the inducible nitric oxide synthase (iNOS) gene among Japanese subjects (control and gastric cancer patients). A higher promoter activity genotype of the HO-1 gene was associated with increased risk for gastric cancer in women. Gastric cancer risk was notably increased in subjects carrying a higher promoter activity genotype for both HO-1 and iNOS compared to those with a lower promoter activity genotype for both genes. Our data suggest that genetic polymorphisms of HO-1 and iNOS modulate individual susceptibility to gastric cancer risk.     

The toll-like receptor 2 (TLR2) -196 to -174 del/ins polymorphism affects viral loads and susceptibility to hepatocellular carcinoma in chronic hepatitis C

Chronic hepatitis C virus (HCV) infection is a major risk factor for hepatocellular carcinoma (HCC). HCV proteins core and NS3 can bind to toll-like receptor 2 (TLR2) and trigger inflammatory responses. Polymorphisms in the TLR2 gene predispose to various forms of malignancy but have not been studied in HCV-associated HCC. Here, we investigated whether single nucleotide polymorphisms (SNPs), rs4696480, rs5743708, rs5743704 and the -196 to -174 del/ins polymorphism of the TLR2 gene affect the risk for HCC in chronic hepatitis C. The study involved 189 and 192 HCV genotype 1 infected patients with and without HCC, respectively, as well as 347 healthy controls. TLR2 alleles were determined by hybridization probe assays and allele-specific short fragment polymerase chain reaction on a LightCycler system. All TLR2 polymorphisms matched the Hardy-Weinberg equilibrium in each study group. Although TLR2 SNPs showed no effect, the frequency of the TLR2 -196 to -174 del allele was significantly higher in patients with HCV-associated HCC (22.5%) than in HCV-infected patients without HCC (15.6%, p = 0.016) and healthy controls (15.3%, p = 0.003). HCV-infected carriers of a TLR2 -196 to -174 del allele had significantly higher HCV viral loads than TLR2 -196 to -174 ins/ins homozygous patients (p = 0.031). Finally, in carriers of the TLR2 -196 to -174 del allele, stimulation of monocytes resulted in significantly lower TLR2 expression levels and interleukin-8 (IL-8) induction than in individuals with the TLR2 -196 to -174 ins/ins genotype (p < 0.05). Our data suggest the TLR2 -196 to -174 del allele to affect HCV viral loads and to increase the risk for HCC in HCV genotype1-infected patients.     

The involvement of promoter methylation and DNA methyltransferase-1 in the regulation of EpCAM expression in oral squamous cell carcinoma

Epithelial cell adhesion molecule (EpCAM) is important for cell proliferation and differentiation but mechanisms regulating their expression are unclear. Because EpCAM may play a role in carcinogenesis, we investigated the clinicopathologic significance of its expression in oral squamous cell carcinoma (OSCC) and the involvement of DNA methylation machinery in regulation of EpCAM expression during tumorigenesis. Immunohistochemical staining for EpCAM expression and DNA methyltransferase-1 (DNMT1) was done in 112 OSCC cases. Tumor genomic DNA was extracted and EpCAM promoter methylation was examined by methylation-specific polymerase chain reaction in 72 OSCC specimens. Immunoreactivity and methylation were correlated with clinicopathologic features. EpCAM expression was undetectable in normal epithelium; high expression was observed in 51% (57/112) of OSCC. Heterogeneity and plasticity of EpCAM expression was observed during tumor development. Allele methylation was found in 51% (37/72) of OSCC cases analyzed. EpCAM expression was associated with promoter methylation (p = 0.008). However, EpCAM expression and promoter methylation did not correlate with clinicopathologic OSCC variables. DNMT1 expression was occasionally observed in basal cells of normal epithelium; high expression was observed in 47% (53/112) of OSCC. DNMT1 did not correlate with EpCAM expression or methylation status. High DNMT1 expression correlated with tumor size (p < 0.0001) histologic differentiation (p = 0.012) and clinical stage (p < 0.0001) of OSCC. EpCAM expression increased during development of OSCC. EpCAM promoter methylation is associated with EpCAM expression levels in OSCC, suggesting an epigenetically mediated regulation of EpCAM expression. Increased DNMT1 protein expression may be involved in histogenesis and progression of OSCC.