No association between EGF gene polymorphism and gastric cancer

Effects of vascular endothelial growth factor and epidermal growth factor on biological properties of gastric cancer cells

INTRODUCTION

The exfoliation of exfoliative cells from gastric serosa into the peritoneum is the main cause of peritoneal metastasis, which is the most common form of postoperative recurrence in gastric cancer. This study investigates the effects of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) on the biological properties of gastric cancer cells.

MATERIAL AND METHODS

mRNA expression of VEGF and EGF in gastric cancer tissues from 80 patients suffering from serosa-infiltrated gastric cancer (T₃) was examined. The differences of proliferation, movement, adhesion and invasion among 4 gastric cancer cell lines were analysed. The mRNA expression of EGF, EGFR, VEGF and VEGFR in the gastric cancer cell lines was examined before and after adding endostatin (Endostar) or cetuximab (Erbitux) to observe changes of gastric cancer cells.

RESULTS

mRNA levels of EGF and VEGF in positive exfoliative cytology cases were significantly higher than negative cases (p < 0.05). The biological properties were reduced sequentially in MGC803, HGC27, BGC823 and SGC7901 (p < 0.05). The mRNA expression of EGF, EGFR, VEGF and VEGFR was the strongest in MGC803, but was attenuated significantly after treatment (p < 0.05).

CONCLUSIONS

Lower survival was related to positive exfoliative cytology, lymphatic node metastasis, serosa-infiltrated and poorly differentiated gastric cancer. The expression of VEGF and EGF was correlated with the properties of gastric cancer cells. Specific inhibition of VEGF and EGF may impair the biological properties of gastric cancer cells in vitro.

No Association between EGF +61 A/G Polymorphism and Increased Risk of Glioma

A single nucleotide polymorphism (SNP) of the epidermal growth factor ( EGF) gene +61 A/G in the 5′-untranslated region has been reported to be associated with susceptibility to glioma. A case-control study (168 glioma patients and 194 normal controls) was conducted to elucidate its possible association with the risk of glioma in the Chinese population. Polymerase chain reaction-restriction fragment length polymorphism assay was used to analyze the EGF genotypes. The genotyping results were further confirmed by direct sequencing. The EGF +61A and +61G allele frequencies in the glioma group were 32.1% and 67.9%, respectively, while they were 30.4% and 69.6% in the healthy controls. Furthermore, the frequency of the A/A, A/G and G/G genotypes in glioma patients was 8.9%, 46.4%, and 44.7%, respectively, and 8.3%, 44.3%, and 47.4% in controls. There was no significant difference between patients and healthy controls. The EGF +61 A/G and +61 G/G genotypes were not significantly associated with risk of glioma compared with the A/A genotype. In addition, no significant association was observed between EGF polymorphism and different histological grades of glioma. These results indicate that the EGF +61 A/G polymorphism is not associated with susceptibility to glioma in the Chinese population. In addition, a literature review revealed a significantly higher rate of the A/A genotype in Caucasian compared with East Asian subjects. Such differences in genotype distribution between Caucasian and Asian people should be taken into account in future studies.

Clinical Implication of EGF A61G Polymorphism in the Risk of Non Small Cell Lung Adenocarcinoma Patients: A Case Control Study

BACKGROUND

The epidermal growth factor (EGF) plays important roles in non-small cell lung cancer (NSCLC) susceptibility and functional polymorphism in the EGF (+61A/G) gene has been linked to increased risk of NSCLC. This study aimed to evaluate the role of the EGF +61A/G polymorphism in risk of NSCLC adenocarcinoma (ADC) occurrence and survival in an Indian population.

MATERIALS AND METHODS

This case- control study included 100 histopathologically confirmed NSCLC (ADC) patients and 100 healthy controls. EGF (A61G) was genotyped by AS-PCR to elucidate putative associations with clinical outcomes. The association of the polymorphism with the survival of NSCLC patients was estimated by Kaplan-Meier curves.

RESULTS

It was found that EGF 61AG heterozygous and GG homozygous genotype is significantly associated with increased risk of NSCLC (ADC) occurrence compared to AA genotype, [OR 2.61 (1.31-5.18) and 3.25 (1.31-8.06), RR 1.51(1.15-2.0) and 1.72 (1.08-2.73) and RD 23.2 (6.90-39.5) and 28.53(7.0-50.1) for heterozygous AG (p=0.005) and homozygous GG (p=0.009)]. Patients homozygous for the G allele exhibited a significantly poor overall survival. The median survival time for patients with EGF 61 AA, AG, and GG genotypes was 10.5, 7.4, and 7.1 months (p=0.02), respectively. NSCLC (ADC) patients with GG + AG exhibited 7.3 months median survival compared to the AA genotype (p=0.009).

CONCLUSIONS

The present study revealed that the EGF A61G genotype may be a novel independent prognostic marker to identify patients at higher risk of occurrence and an unfavourable clinical outcome.

Association between EGF +61 A>G polymorphism and gastric cancer risk: A meta-analysis

Previous studies suggested an association between the EGF +61 A>G polymorphism and susceptibility to gastric cancer, but the results have been inconsistent. To draw a more precise risk estimation of the association, we performed a meta-analysis of published studies. PubMed, EMBASE, Google Scholar and the Chinese Wanfang databases were systematically searched to identify relevant studies. There were 7 studies involving 1992 cases of gastric cancer and 3202 controls in this meta-analysis. Our study showed that, overall, the EGF +61 A>G polymorphism was significantly associated with the increased risk of gastric cancer in allele model (G vs. A: OR=1.18, 95% CI=1.00-1.39), dominant model (GG + GA vs. AA: OR=1.28, 95% CI=1.05-1.55), homozygous model (GG vs. AA: OR=1.31, 95% CI=1.06-1.63) and heterozygous model (GA vs. AA: OR=1.25, 95% CI=1.01-1.53). The stratified analysis by ethnicity revealed a significant association between EGF +61 A>G polymorphism and gastric cancer risks in Asians. This meta-analysis indicates that EGF +61 A>G polymorphism may increase the risk of gastric cancer, especially in Asians. Large-sized, well-designed studies involving different ethnic groups should be conducted to confirm this association.

EGF +61A/G polymorphism contributes to increased gastric cancer risk: evidence from a meta-analysis

Background

Epidermal growth factor (EGF) plays a pivotal role in cell proliferation, differentiation, and tumorigenesis of epithelial tissues. Variation of the EGF +61A/G (rs4444903) can lead to an alteration in EGF production and/or activity, which may result in individual susceptibility to gastric cancer. Studies investigating the association between EGF +61A/G polymorphism and gastric cancer risk produced inconsistent results. The aim of this study was to quantitatively summarize the evidence for such an association.

Methods

Eligible studies on the association between EGF +61A/G polymorphism and gastric cancer risk were identified by search of electronic databases including PubMed, EMBASE, Cochrane Library, and Chinese Biomedical Literature database (CBM). Data were extracted by two independent authors and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Metaregression and subgroup analyses were performed to identify the source of heterogeneity.

Results

Finally, six case–control studies with 1547 gastric cancer cases and 2762 controls were eventually identified. Overall, significant increased gastric cancer risk was found when all studies were pooled in the meta-analysis (GG vs. AA: OR = 1.438, 95% CI 1.021–2.025, P = 0.038; GG + AG vs. AA: OR = 1.256, 95% CI 1.025–1.539, P = 0.028; GG vs. AG + AA: OR = 1.265, 95% CI 1.002–1.596, P = 0.048). In subgroup analysis by ethnicity, source of control, study quality, and HWE in controls, significant increased gastric cancer risk was observed in Asians, population-based studies, high quality studies, and studies consistent with HWE. In subgroup analysis according to tumor location, and histological type, significant association was observed in all subgroups.

Conclusions

This meta-analysis suggested that the EGF +61A/G polymorphism contributes to increased gastric cancer risk, especially in Asian populations. Further well-designed studies based on large sample size in diverse populations are needed to confirm this association.

Association of EGF and p53 gene polymorphisms and colorectal cancer risk in the Slovak population

During the transformation process single nucleotide polymorphisms (SNPs) of key genes, such as p53 Arg72Pro or EGF A61G, may mediate various cellular processes. These variants may be associated with colorectal cancer risk (CRC), but conflicting findings have been reported. The purpose of this study was to determine the association of the SNPs in 5′ UTR of EGF A61G and p53 Arg72Pro and CRC in the Slovak population. The present case-control study was carried out in 173 confirmed CRC patients and 303 healthy subjects. Genotyping was performed by PCR-RFLP methods. Significant association was observed between age and CRC risk (p=0.001). Lower CRC risk was seen in younger patients carrying genotype p53 Arg72Pro (0.14; 95% CI 0.02–0.99, p=0.049). Gender-stratified analysis showed a significant inverse association of the polymorphism EGF G61G with CRC risk (0.48; 95% CI 0.2–0.9, p=0.04) only in male patients. Tumour site genotype distribution revealed that female patients with localized colon cancer were significantly associated with p53 Pro72Pro genotype (4.0; 95% CI 1.27–12.7, p=0.04) whereas the cancer of rectosigmoid junction was associated with the EGF G61G genotype (4.5; 95% CI 1.2–16.97, p=0.02). Combination of p53 Arg72Pro or EGF A61G polymorphisms were not associated with CRC risk by using logistic regression.

Relationship between EGF, TGFA, and EGFR Gene Polymorphisms and Traditional Chinese Medicine ZHENG in Gastric Cancer

In traditional Chinese medicine (TCM), correct syndrome differentiation is the most important principle guiding the prescription of Chinese herbal formulae for the treatment of gastric cancer (GC). We aimed to reveal the genetic mechanisms underlying GC syndrome differentiation (ZHENG) in a population of 387 GC patients. Twenty-nine single nucleotide polymorphisms (SNPs) in EGF, TGFA, and EGFR were investigated. Two SNPs, rs11466285 in TGFA and rs884225 in EGFR, were significantly associated with the distribution of ZHENG (P < 0.05). The rs11466285 TT genotype increased the risk of damp heat with toxin (DHT) and deficiency of both Qi and yin (DQY) compared with obstruction of blood stasis (OBS). The rs884225 AA genotype could increase the risk of DQY and deficiency of both Qi and blood (DQB) compared with yin deficiency due to stomach heat (YDSH). Parallel comparison among the SNPs and syndrome types revealed that DQB was distinct from YDSH, disharmony between the liver and stomach, stagnation of phlegm muddiness (SPM), OBS, and other syndromes at several SNP loci (P < 0.05). The rs11466285 TT and rs884225 AA genotypes exhibit increased risk of DQB compared with OBS and SPM (P < 0.05), respectively. In conclusion, the formation of GC ZHENG was related to EGF, TGFA, and EGFR gene polymorphisms.

EGF +61A>G polymorphism and gastrointestinal cancer risk: a HuGE review and meta-analysis

Emerging evidences from preclinical and clinical studies have shown that epidermal growth factor (EGF) has some effectiveness against endogenously arising carcinogenesis. Functional +61A>G polymorphism (rs4444903 A>G) in the promoter region of the EGF gene was observed to modulate EGF levels, thus affecting the susceptibility to gastrointestinal cancer; but individually published studies showed inconclusive results. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to derive a more precise estimation of the association between EGF +61A>G polymorphism and gastrointestinal cancer risk. A literature search of Pubmed, Embase, Web of Science and Chinese BioMedical databases from inception through July 2012 was conducted. Twelve studies were assessed with a total of 2868 gastrointestinal cancer cases and 4278 healthy controls. When all the eligible studies were pooled into the meta-analysis, the results showed that the G allele and GG genotype of EGF +61A>G polymorphism might increase the risk of gastrointestinal cancer. In the stratified analysis by cancer types, the G allele and GG genotype of EGF +61A>G polymorphism showed displayed significant correlations with increased risk of esophageal cancer. We also found significant correlations between the G carrier (GG+AG) and GG genotype of EGF +61A>G polymorphism and colorectal cancer risk. However, EGF +61A>G polymorphism did not appear to have an influence on gastric cancer susceptibility. Results from the current meta-analysis indicate that EGF +61A>G polymorphism might increase the risk of esophageal and colorectal cancers. Nevertheless, further studies are needed to determine whether genetic associations between EGF +61A>G polymorphism and susceptibility to gastric cancer are significant.

Functional epidermal growth factor gene polymorphisms and risk of gastric cancer

Epidermal growth factor (EGF) is critical in cancer progression and various genotypes of the EGF gene have been reported to be correlated with susceptibility to gastric cancer; however, the results are unclear. The aim of this study was to explore the associations of functional EGF gene polymorphisms and risk of gastric cancer in a Chinese population. We genotyped seven functional single-nucleotide polymorphisms (SNPs) of the EGF gene [rs3756261, rs11568835 and rs4444903 in the promoter region; rs11568943, rs2237051 and rs11569017 in the non-synonymous exon region and rs3733625 in the 3′ untranslated region (UTR)] in a hospital-based case-control study, including 387 gastric cancer cases and 392 healthy controls by polymerase chain reaction-ligation detection reaction (PCR-LDR) methods. We found that individuals carrying the AG/GG genotype of rs2237051 (Ile to Met) in the exon region had an increased risk of gastric cancer (adjusted OR=1.577; 95% CI=1.163–2.138), compared with the wild-type homozygous AA genotype. The heterozygous AG/GG genotype of rs3733625 in the 3′UTR demonstrated a protective effect (adjusted OR=0.690; 95% CI=0.501–0.951), compared with the homozygous AA genotype. In addition, the effects of the two SNPs were more evident in intestinal gastric cancer (P<0.05); however, this was not case for the diffuse type (P>0.05). These findings indicate that a change in amino acids from isoleucine to methionine of rs2237051 and rs3733625 in the 3′UTR may contribute to the etiology of intestinal gastric cancer in the Chinese population.

Prognostic implications of genetic variants in advanced non-small cell lung cancer: a genome-wide association study

The prognostic significance of inherited genetic variants in advanced-stage non-small cell lung cancer (NSCLC) patients remains unknown. In this study, we genotyped 271 817 single-nucleotide polymorphisms in 348 advanced NSCLC patients who received chemotherapy and analyzed their association with prognosis by using Cox proportional hazard regression model adjusted for known prognostic factors. Top candidate single-nucleotide polymorphisms (SNPs) were selected using the bootstrap re-sampling procedure. Median age of patient population was 56 years. Proportions of female, never smokers and adenocarcinoma were 64.9, 67.5 and 80.4%, respectively. We identified 17 top candidate SNPs related to prognosis using cut-off minimum P value of <5.0 × 10(-5) in at least 70% of 1000 bootstrap samples. These SNPs were located in the genomic regions of the FAM154A, ANKS1A, DLST, THSD7B, NCOA2, CDH8, SLC35D2, NALCN and EGF genes. The most significant SNP, rs1571228 (9p22.1:FAM154A), was significantly associated with overall survival in dominant model [AG+GG to AA, hazard ratio (HR) of death (95% CI) = 0.53 (0.42-0.67); P = 2.025 × 10(-7)]. The SNP at 4q25:EGF, rs11098063, for which some genetic variations was previously reported to be associated with prognosis, also showed significant association with overall survival in additive model [CC versus CT versus TT, HR (95% CI) = 1.00 versus 0.61 (0.47-0.78) versus 0.39 (0.19-0.79); P = 9.582 × 10(-6)]. Survival differences according to the genotype of these SNPs were independent of sex, smoking, histology and chemotherapy regimens. These results suggested the variants at multiple genetic loci might contribute to the risk of death in advanced NSCLC patients receiving chemotherapy.

Epidermal growth factor 61A>G polymorphism is associated with risk of hepatocellular carcinoma: a meta-analysis

The association between hepatocellular carcinoma (HCC) and the 61A>G polymorphism in the epidermal growth factor (EGF) gene has been analyzed in several studies, but results have been inconsistent. The aim of this study was to integrate previous findings and explore whether this polymorphism is associated with susceptibility to HCC. A meta-analysis was performed by searching PubMed, Web of Science, and Cochrane Library databases. Data were extracted using predefined form and pooled odds ratios (OR) with 95% confidence intervals (CI) and were calculated to evaluate the strength of this association. Five studies involving 690 cases, 514 healthy controls, and 1419 controls with cancer-free liver diseases were identified. On the basis of healthy controls, the significant main effects on HCC risk were observed in a heterozygote comparison (OR=1.76, 95% CI 1.07-2.90, p=0.02) and a dominant genetic model (OR=1.65, 95% CI 1.03-2.66, p=0.04). On the basis of the controls with cancer-free liver diseases, a significantly increased risk of HCC was found in all the genetic models. Subgroup analyses stratified by ethnicity and etiology of HCC also showed positive associations. The EGF 61G allele is a risk factor for developing HCC without the influence of ethnic and etiological diversity.

Association between EGF +61 genetic polymorphisms and non-small cell lung cancer increased risk in a Portuguese population: a case-control study

Epidermal growth factor (EGF) and its receptor play critical roles in non-small cell lung cancer (NSCLC) carcinogenesis. A functional polymorphism in the EGF gene has been linked to increased cancer susceptibility. This study aimed to evaluate the role of the EGF +61A/G polymorphism as risk factors in NSCLC patients. For the present case-control study, we analyzed 112 NSCLC and 126 cancer-free controls from Portugal. Following DNA isolation from peripheral blood, EGF +61A/G polymorphism was assessed by polymerase chain reaction-restriction fragment length polymorphism. Univariate and multivariate logistic regression analyses were used to calculate odds ratio (OR) and 95 % confidence intervals (95 % CI). False-positive report probability was also assessed. The EGF +61 genotypes frequencies in NSCLC were AA (23.2 %), AG (51.8 %), and GG (25 %) and in controls, AA (40.5 %), AG (41.3 %), and GG (18.3 %). When compared to the reference genotype (EGF +61A/A), we found a statistically significant association between EGF +61 A/G (OR = 2.142, 95 % CI 1.170-3.924) and EGF +61G/G (OR = 2.398, 95 % CI 1.157-4.968) genotypes and susceptibility to development of NSCLC. Furthermore, stratification by sex revealed a trend to increased risk of males carrying +61A/G genotype for developing NSCLC (OR = 2.044, 95 % CI 0.998-4.188) when compared to A/A genotype. Our data suggest an increased risk to develop NSCLC in Portuguese population carrying the EGF +61A/G and +61G/G genotypes.

Lack of EGFR mutations benefiting gefitinib treatment in adenocarcinoma of esophagogastric junction

Background

The epidermal growth factor receptor (EGFR) inhibitor, gefitinib, has been reported to successfully treat advanced non-small cell lung cancer patients with genetic mutations in EGFR. The aim of this study was to investigate the existence of EGFR mutations in carcinoma of esophagogastric junction, and also to explore the possibility of treating carcinoma of esophagogastric junction using gefitinib.

Methods

From Aug. 2009 to Jun. 2010, 65 patients with carcinoma of esophagogastric junction underwent surgical resection. The tumor tissue and corresponding blood specimens were collected from all cases. The DNA was extracted and PCR amplification was accomplished based on designed primers for exons 18, 19, 20, and 21. EGFR exons 18, 19, 20 and 21 of both cancer cell and white blood cell were finally successfully sequenced.

Results

In exon 20, a variant from CAG to CAA at codon 787 (2361G-> A) was identified in 19 patients, which was a genomic variation of EGFR since it was found in both cancer tissue and white blood cells. This EGFR alteration was a synonymous single nucleotide polymorphism (SNP) since CAA and CAG were encoding the same amino-acid of Glutamine (Q787Q, NCBI database 162093G > A, SNP ID: rs10251977). No genetic alteration was found in exons 18, 19 or 21.

Conclusions

Adenocarcinoma of esophagogastric junction rarely presents EGFR mutation, especially gefitinib-associated mutations such as L858R, or delE746-A750. This means that the gefitinib-based gene target therapy should not be recommended for treating carcinoma of esophagogastric junction.

Meta-analysis of epidermal growth factor polymorphisms and cancer risk: involving 9,779 cases and 15,932 controls

The epidermal growth factor (EGF) pathway stimulates proliferation and differentiation of epidermal and epithelial tissues, and plays an important role in tumorigenesis. The association between EGF polymorphisms and cancer risk is controversial; thus, we performed this meta-analysis. Overall, 41 case-control studies with 9,779 cases and 15,932 controls were retrieved. We found that EGF +61A/G polymorphism increased overall cancer risk (G allele vs. A allele: OR=1.181, 95% CI=1.077-1.295, P(heterogeneity) < 0.001; GG vs. AA: OR=1.370, 95% CI=1.143-1.641, P(heterogeneity) < 0.001; GG+GA vs. AA: OR=1.175, 95% CI=1.047-1.318, P(heterogeneity) < 0.001). In the stratified analysis by cancer type, the +61 G allele was a risk factor for colorectal cancer, esophageal carcinoma, gastric cancer, and hepatocellular carcinoma. Individuals who carried +61G allele had higher cancer susceptibility in mixed and European racial subgroups. An increased association was detected in the hospital-based subgroup. No significant association was found among EGF -1380A/G, -1744G/A, rs6983267T/G polymorphisms and cancer risk.

EGF61 polymorphism predicts complete pathologic response to cetuximab-based chemoradiation independent of KRAS status in locally advanced rectal cancer patients

BACKGROUND

Cetuximab has shown significant clinical activity in metastatic colon cancer. However, cetuximab-containing neoadjuvant chemoradiation has not been shown to improve tumor response in locally advanced rectal cancer patients in recent phase I/II trials. We evaluated functional germline polymorphisms of genes involved in epidermal growth factor receptor pathway, angiogenesis, antibody-dependent cell-mediated cytotoxicity, DNA repair, and drug metabolism, for their potential role as molecular predictors for clinical outcome in locally advanced rectal cancer patients treated with preoperative cetuximab-based chemoradiation.

METHODS

130 patients (74 men and 56 women) with locally advanced rectal cancer (4 with stage II, 109 with stage III, and 15 with stage IV, 2 unknown) who were enrolled in phase I/II clinical trials treated with cetuximab-based chemoradiation in European cancer centers were included. Genomic DNA was extracted from formalin-fixed paraffin-embedded tumor samples and genotyping was done by using PCR-RFLP assays. Fisher's exact test was used to examine associations between polymorphisms and complete pathologic response (pCR) that was determined by a modified Dworak classification system (grade III vs. grade IV: complete response).

RESULTS

Patients with the epidermal growth factor (EGF) 61 G/G genotype had pCR of 45% (5/11), compared with 21% (11/53) in patients heterozygous, and 2% (1/54) in patients homozygous for the A/A allele (P < 0.001). In addition, this association between EGF 61 G allele and pCR remained significant (P = 0.019) in the 59 patients with wild-type KRAS.

CONCLUSION

This study suggested EGF A+61G polymorphism to be a predictive marker for pCR, independent of KRAS mutation status, to cetuximab-based neoadjuvant chemoradiation of patients with locally advanced rectal cancer.

Association between EGF +61A/G polymorphism and gastric cancer in Caucasians

AIM: To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study.

METHODS: Polymerase chain reaction resctriction fragment lenght polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian.

RESULTS: Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021).

CONCLUSION: In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.

Association between EGF +61 G/A and glioma risk in a Chinese population

Background

Epidermal growth factor (EGF) is critical in cancer process. EGF and EGF receptor (EGFR) interaction plays a pivotal role in cell proliferation, differentiation, and tumorigenesis of epithelial tissues. Variations of the EGF +61G/A (rs4444903) may lead to an alteration in EGF production and/or activity, which can result in individual susceptibility to brain glioma. The purpose of this study was to investigate the potential association between EGF +61G/A and brain glioma in a Chinese population.

Methods

In this study, we analyzed single nucleotide polymorphism of EGF +61G/A in 677 patients with glioma and 698 gender- and age-matched controls. Genotyping was performed by polymerase chain reaction-ligation detection reaction (PCR-LDR) method.

Results

The A allele (minor Allele) was 33.0% in cases and 27.3% in controls. The additive model was more powerful to reveal the association in our study than that of recessive and dominant model. Our data showed the genotype G/A and A/A was associated with increased risk for glioma (adjusted OR = 1.48, 95%CI: 1.17-1.87, p = 0.001 for G/A, adjusted OR = 1.81, 95%CI: 1.20-2.72, p = 0.005 for A/A, respectively), and for glioblastoma (adjusted OR = 1.51, 95%CI: 1.06-2.17, p = 0.024 and adjusted OR = 2.35, 95%CI: 1.34-4.15, p = 0.003, respectively). The A allele significantly increased glioma risk (OR = 1.31, 95%CI: 1.11-1.55, p = 0.001). The additive model (G/G vs G/A vs A/A) showed that both G/A and A/A genotype increased glioma risk (adjusted OR = 1.40, 95% CI: 1.17-1.66, p = 0.0002).G/A and A/A genotypes or EGF +61 A allele increased risk in both low and high WHO grade glioma. Non-smokers with G/A and A/A genotype showed increased glioma risk compared with G/G genotype (adjusted OR = 1.72, 95%CI: 1.29-2.30, p = 0.0002 and adjusted OR = 1.81, 95%CI: 1.10-2.99, p = 0.020, respectively). This association was not found in ever- or current-smokers.

Conclusions

Our study indicated that G/A and A/A genotypes or EGF +61 A allele were associated with higher glioma risk in Chinese. This is in contrast with previous studies which reported G allele as a risk factor of glioma in Caucasian. The role of EGF +61 A/G polymorphism in glioma susceptibility needs further investigation.

No association of EGF 5'UTR variant A61G and hepatocellular carcinoma in Chinese patients with chronic hepatitis B virus infection

OBJECTIVE

Epidermal growth factor (EGF) has many biological functions, including mitogenesis, tumorigenesis, and proliferation of epidermal tissues. Previous studies have reported that the EGF +61 (A/G) single nucleotide polymorphism in the 5'-untranslated region of the EGF gene is functional, and is associated with development of hepatocellular carcinoma (HCC) in liver cirrhosis and various malignancy. Our aim was to investigate whether EGF gene A61G polymorphism could be implicated in susceptibility to and/or clinicopathological characteristics of HCC in Chinese patients with chronic hepatitis B virus (HBV) infection.

METHODS

This polymorphism was studied in 387 patients with chronic HBV infection and in 208 healthy volunteers using restriction fragment-length polymorphism. The patients were divided into two groups: those without (n = 172) and those with HCC (n = 215). These 215 HCC patients with chronic HBV infection were designated as cases, and the remaining 172 patients without HCC served as controls.

RESULTS

There were no significant differences in EGF genotype or allelic frequencies between cases and controls nor was EGF genotype or allelic frequencies associated with tumour number, size, growth phase, stage, and invasiveness. We also found ethnic heterogeneity in the functional EGF polymorphism.

CONCLUSIONS

The present results show that although EGF gene A61G polymorphism is associated with development of HCC in liver cirrhosis, it is not sufficient for HCC in Chinese patients with chronic HBV infection.

Association between epidermal growth factor polymorphism and esophageal squamous cell carcinoma susceptibility

Genetic factors are known to be important in the development of esophageal squamous cell carcinoma (ESCC). Epidermal growth factor (EGF) can activate several signaling pathways leading to proliferation, differentiation, and tumorigenesis of epithelial tissues by binding with its receptor. Interindividual variations in EGF production were genetically contributed to EGF +61 G/A polymorphism. The purpose of this study is to investigate the potential association between EGF gene polymorphism and ESCC in a Chinese population. In this study, we analyzed single nucleotide polymorphism of EGF +61 G/A in 158 patients with ESCC and 212 age- and sex-matched controls in a Chinese population using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy and DNA sequencing. The variant genotypes of GA/AA were associated with a significantly decreased risk of ESCC compared with the wild-type homozygote GG (OR = 0.657, 95% CI: 0.434-0.996). However, no significant difference was observed between the EGF +61 G/A polymorphism and the risk of ESCC when the analyses were stratified in terms of age, gender, smoking status, different clinical stage, and lymph node status. The EGF +61 G/A polymorphism is associated with ESCC in a Chinese population. Our data suggests that the EGF gene may play a role in the development of ESCC.

Association between EGF promoter polymorphisms and cancer risk: a meta-analysis

EGF promoter polymorphisms are observed to modulate EGF levels and thought to have effect on susceptibility to various carcinomas but the results are inconsistent. In this meta-analysis, we assessed published studies of the association between three EGF polymorphisms and cancer risk from 21 studies with 14,609 subjects for EGF G61A, from two studies with 2,535 subjects for G-1380A and A-1744G, respectively. For EGF G61A, the contrast of homozygote (OR=0.80, 95% CI=0.65-0.98), allele (OR=0.90, 95% CI=0.81-0.99) and dominant model (OR=0.86, 95% CI=0.74-0.99) produced significant association among 21 studies with relatively large heterogeneity (Pheterogeneity<0.001). Through the stratified analysis, heterogeneity decreased significantly. In the stratified analysis by racial descent, the significant risks were found among Asians for homozygote contrast (OR=0.83, 95% CI=0.69-0.99, Pheterogeneity=0.506) and Americans for the contrast of homozygote (OR=0.50, 95% CI=0.30-0.84, Pheterogeneity=0.051), allele (OR=0.70, 95% CI=0.51-0.96, Pheterogeneity=0.008) and dominant model (OR=0.57, 95% CI=0.42-0.77, Pheterogeneity=0.28). No significant associations were found in all Caucasians genetic models. In the subgroup analyses by cancer types, for gastric cancer and esophageal cancer significant associations were found in all genetic models without heterogeneity. Significant risk was also found in the contrast of homozygote (OR=0.41, 95% CI=0.20-0.81, Pheterogeneity=0.184) and recessive model (OR=0.53, 95% CI=0.33-0.85, Pheterogeneity=0.384) for hepatoma and recessive model (OR=0.72, 95% CI=0.53-0.99, Pheterogeneity=0.474) for glioma. For EGF G-1380A and A-1744G, no significant associations were found in all genetic models. This meta-analysis suggests that the EGF G61A polymorphism most likely contributes to decreased susceptibility to cancers among Asians and Americans, and A allele may be a protective factor for gastric cancer, esophageal cancer, hepatoma and glioma. Both EGF G-1380A and A-1744G is marginally associated with cancer susceptibility.

Cell proliferation-related genetic polymorphisms and gastric cancer risk: systematic review and meta-analysis

Apart from Helicobacter pylori infection and lifestyle factors, host genetic susceptibility has been suggested to contribute to individual variation in gastric cancer risk as well. Aiming to evaluate the associations between host cell proliferation-related genetic polymorphisms and gastric cancer susceptibility, we reviewed the related studies published until 15 September 2008 and quantitatively summarized the associations of the most widely studied polymorphisms (TP53 Arg72Pro, L-myc EcoRI) using meta-analysis. Fifty-five eligible studies were included in this review. Twenty-three polymorphisms significantly related to gastric cancer risk in at least one study were identified. Polymorphisms determining higher levels of growth factors, which are important for tissue repair, were recently observed to be associated with reduced risk of gastric cancer. In the meta-analysis, TP53 72Pro was associated with increased risk of diffuse gastric cancer among Asians (OR, 1.44; 95% CI, 1.04-1.99), but decreased risk of intestinal gastric cancer among Caucasians (OR, 0.56; 95% CI, 0.36-0.89). This review suggests that cell proliferation-related genetic polymorphisms could be candidate biomarkers of gastric cancer risk, but current evidence for the use for risk stratification is still very limited. Modestly significant associations in meta-analyses stratified by population or type of gastric cancer may be observed by chance because of the limited number of studies and small sample size. Larger studies are warranted to clarify the effect of cell proliferation-related genetic polymorphisms on gastric carcinogenesis.

Ovarian Cancer and Genetic Susceptibility: Association of A61G Polymorphism in the EGF Gene

Growth factors play an essential role in regulating cellular proliferation, and lack of control is characteristic of malignant development. The epidermal growth factor ( EGF) gene codifies a growth factor that binds to the EGF receptor (EGFR), which is involved in activating pathways that promote cellular proliferation, survival, migration and differentiation. The purpose of this study was to appraise the association between EGF gene A61G polymorphism with ovarian cancer susceptibility. A total of 564 DNA samples were analysed from 175 women with ovarian cancer and 389 women without cancer, through PCR-RFLP. We found a decreased risk for developing ovarian cancer in GG carriers compared to AA carriers (OR = 0.46, CI = 0.25–0.83, P = 0.010). The seemingly protective role in GG carriers was observed in women under 53 years of age (OR = 0.38, CI = 0.16–0.86, P = 0.011) and in patients diagnosed with advanced stage disease (OR = 0.38, CI = 0.18–0.81, P = 0.012). Allelic comparison evidenced similar results, with decreased risk for G allele. We further observed a linear trend for G allele in cancer risk. Moreover, we analysed the influence of genotypes in the time to onset of the disease and observed that GG carriers had ovarian cancer later than AA carriers ( P = 0.035). We hypothesize that this polymorphism confers protection for ovarian cancer development.

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.

A functional epidermal growth factor (EGF) polymorphism, EGF serum levels, and esophageal adenocarcinoma risk and outcome

PURPOSE

The epidermal growth factor (EGF) pathway is important in esophageal adenocarcinoma (EAC) tumorigenesis. We hypothesized that the EGF A61G homozygous variant genotype (GG) is (a) both a risk and poor prognostic factor for EAC and (b) associated with higher EGF serum levels in individuals with gastroesophageal reflux disease (GERD).

EXPERIMENTAL DESIGN

Using unconditional logistic regression, we compared EGF A61G in 312 EAC cases and 447 GERD-free controls, adjusting for age, gender, smoking history, and healthy adult body mass index. Using the method of Kaplan and Meier, log-rank tests, and Cox proportional hazard models, we correlated EGF A61G with overall and failure-free survival in the EAC cases. Serum EGF levels and EGF genotype (G/G versus others) were correlated in 144 GERD patients using Wilcoxon rank sum tests.

RESULTS

The EGF A61G G/G genotype conferred increased EAC risk, with an adjusted odds ratio of 1.81 (95% confidence interval, 1.2-2.7), and was even higher in the subgroup of EAC patients with concurrent Barrett's esophagus (adjusted odds ratio, 2.18; 95% confidence interval, 1.3-3.7). However, EGF A61G was not associated with a more aggressive phenotype or prognosis in EAC patients. Higher serum EGF levels were found in GERD patients carrying G/G compared with A/A or A/G (P = 0.03, Wilcoxon rank sum test).

CONCLUSION

The EGF A61G G/G genotype is associated with a near 2-fold greater risk of EAC. The G/G allele was also associated with higher EGF levels in tumor-free patients with GERD. EGF genotyping can potentially identify high-risk patients with GERD and Barrett's metaplasia who might benefit from increased surveillance.

EGF promoter SNPs, plasma EGF levels and risk of breast cancer in Chinese women

Epidermal growth factor (EGF), a potent mitogenic peptide, plays an important role in the development of cancers, including breast cancer. Previous studies showed that plasma EGF levels may influence the risk of cancer. In the current study, we hypothesized that genetic variants in the promoter region of EGF may influence plasma EGF levels and therefore are associated with breast cancer susceptibility. We genotyped three EGF polymorphisms (G61A, G-1380A, and A-1744G) in the promoter region by PCR-RFLP and measured plasma EGF levels using an enzyme immunoassay in a case-control study of Chinese women. We found that the mean plasma EGF levels in breast cancer patients (249.06 +/- 197.54 pg/ml) were significantly lower than those in controls (982.41 +/- 375.57 pg/ml, P < 0.001). There was a significant difference of plasma EGF levels among different genotypes carriers of the G-1380A locus in 654 controls (P = 0.007). After adjustment for age, body mass index, family history of cancer, age at menarche, and menopause status, EGF-1380AA carriers had significantly higher plasma EGF levels than -1380GG carriers did (P = 0.003). However, we did not find any significant associations between the three EGF polymorphisms (G61A, G-1380A, and A-1744G) and the risk of breast cancer. These findings indicated that plasma EGF levels served as a protective marker against breast cancer in our study and EGF G-1380A variant might be a modifier on it. Further studies are warranted to verify these findings.

Variant genotypes and haplotypes of the epidermal growth factor gene promoter are associated with a decreased risk of gastric cancer in a high-risk Chinese population

Epidermal growth factor (EGF), a ligand of the EGF receptor, plays a critical role in the development of gastric cancer. Genetic variants in its promoter region may influence transcription activity and contribute to gastric cancer predisposition. To test this hypothesis, we genotyped three EGF promoter polymorphisms (G61A, G-1380A, and A-1744G) in a case-control study of 675 gastric cancer cases and 704 cancer-free controls. We found that the variant genotypes of EGF 61GA/AA were associated with a significantly decreased risk of gastric cancer (OR = 0.77, 95% CI = 0.61-0.95), when compared with wild-type homozygote 61GG. In the combined analysis with all three loci of EGF, subjects carrying one or more variant loci had a significantly decreased risk of gastric cancer in a dose-response manner (adjusted OR = 0.58, 95% CI = 0.42-0.80 for subjects carrying one variant locus and OR = 0.46, 95% CI = 0.32-0.66 for those carrying two to three variant loci, respectively; trend test: chi(2) = 16.14, P < 0.001). Compared with the most common haplotype GGA, haplotypes AGA, GGG and GAA (each containing one variant allele) were associated with 33%, 29% and 34% significantly decreased risk of gastric cancer (adjusted OR = 0.67, 95% CI = 0.55-0.82 for AGA; OR = 0.71, 95% CI = 0.57-0.88 for GGG and OR = 0.66, 95% CI = 0.52-0.84 for GAA, respectively). Our findings indicate that variant genotypes and haplotypes of EGF promoter might play a role in gastric carcinogenesis.

Genetic polymorphisms of the epidermal growth factor and related receptor in non-small cell lung cancer--a review of the literature

Worldwide, approximately 1.3 billion individuals are current smokers, and smoking is the second major cause of death. Currently, lung cancer is the most common type of cancer in Europe, and the third in the U.S. Until now, cytotoxic chemotherapy has had a limited impact on survival in metastatic non-small cell lung cancer (NSCLC). The central role of epidermal growth factor (EGF) and its receptor (EGFR) in lung carcinogenesis is well recognized. Genetic polymorphisms are variants in individual genomes that may be responsible for different functional molecular roles and contribute to variability in drug pharmacokinetic and pharmacodynamic processes. Herein, we review the literature on EGF and EGFR functions and activities, particularly the current role of their functional polymorphisms as related to NSCLC.

Epidermal growth factor 61 A/G polymorphism and uterine cervical cancer

Cervical cancer, the second most common malignancy in women worldwide, is almost invariably associated with infection by human papillomavirus (HPV). However, although many women are infected with high-risk types of HPV, only a subset of infected women will ever develop cervical cancer. Therefore, host genetic factor may play a role in cervical carcinogenesis. Alterations in epidermal growth factor receptor (EGFR) are common events in cervical cancer. Therefore, we hypothesized that a functional polymorphism in the 5′ untranslated region of the epidermal growth factor (EGF) gene, a natural ligand of the EGFR, may play a role in the cervical carcinogenesis and tumor invasiveness. We assessed the possible association between EGF +61 A/G polymorphism and cervical cancer risk in a hospital-based case–control study among 337 Korean women (168 cases, 169 age-matched controls). The frequencies of EGF +61 allele and genotype were not different between cases and controls. We observed increasing trend of lymph node metastasis from A/A homozygous genotype toward G/G homozygous genotype. We did not find any evidence that EGF +61 A/G polymorphism was associated with individual susceptibility of cervical cancer. However, although it was not statistically significant, the increasing trend of lymph node metastasis according to EGF genotype suggests the possibility that individual variance of EGF expression may be associated with cervical cancer invasiveness. We also confirmed that there exists striking ethnic heterogeneity of EGF genotype between Caucasian and East Asian population

Association study between epidermal growth factor receptor and epidermal growth factor polymorphisms and endometriosis in a Japanese population

OBJECTIVE

We investigated a possible association between endometriosis and polymorphisms in the genes encoding epidermal growth factor (EGF) receptor (EGFR) and EGF in a Japanese population.

METHODS

We compared the distribution of the Egfr+2073 A/T and Egf+61 G/A polymorphisms by polymerase chain reaction-restriction fragment length polymorphism analysis in 146 affected women and 181 controls.

RESULTS

No significant differences in the frequency and genotype distribution of the Egfr+2073 A/T and Egf+61 G/A polymorphisms were found between endometriosis patients with all disease stages and controls. Stratification by disease stage had no effect on the results.

CONCLUSION

The Egfr+2073 A/T and Egf+61 G/A polymorphisms are not associated with an increased risk of endometriosis in a Japanese population.

Genetic factors involved in the development of Helicobacter pylori-related gastric cancer

Developmental process to gastric cancer by Helicobacter pylori infection consists of three steps: (1) H. pylori infection; (2) gastric atrophy development; and (3) carcinogenesis. In each step, genetic traits may influence the process, interacting with lifestyle. In the step of H. pylori infection, two lines of genetic polymorphisms were assumed: one influencing gastric acid inhibition interacting with smoking, and the other concerning innate immune response attenuation. The former includes functional polymorphisms of IL-1B (C-31T or tightly linked T-511C), and TNF-A (T-1031C and C-857T), and the latter possibly includes NQO1 C609T. In the step to gastric atrophy, polymorphisms pertaining to the signal transduction from cytotoxin-associated gene A (PTPN11 A/G at intron 3) and to T-cell responses (IL-2 T-330G and IL-13 C-1111T) were hypothesized. There are a limited number of epidemiological genotype studies on the final step of literal carcinogenesis, potentially interacting with smoking, a low vegetable and fruit intake, and salty foods, the well-documented risk factors. In past case-control studies on the associations between genotype and gastric cancer risk, the cases consisted of H. pylori-related and unrelated gastric cancer patients and the controls consisted of individuals including the uninfected (H. pylori unexposed and exposed) and the infected with and without gastric atrophy. Accordingly, it was not clear whether the observed risk was for H. pylori-related or -unrelated gastric cancer, nor which step was involved in the observed associations even when nearly all cases were H. pylori-related. In order to elucidate the genetic traits of H. pylori-related gastric cancer, stepwise evaluation will be required.

Inducible nitric oxide synthase polymorphism is associated with the increased risk of differentiated gastric cancer in a Japanese population

AIM: To examine the association of inducible nitric oxide synthase (iNOS) C150T polymorphism with gastric cancer, as well as with gastric atrophy and H pylori seropositivity.

METHODS: A single nucleotide polymorphism of iNOS C150T was examined for 454 Japanese health checkup examinees (126 males and 328 females) aged 35 to 85 years without a history of cancer and 202 gastric cancer patients (134 males and 68 females) aged 33 to 94 years with pathologically confirmed diagnosis of gastric adenocarcinoma.

RESULTS: The iNOS C150T polymorphism was not associated with gastric atrophy or with H pylori seropositivity. The odds ratio (OR) of the C/T + T/T for gastric cancer was increased without statistical significance (OR=1.19, 95% confidence interval (CI): 0.68-2.08). In the differentiated subgroup (n = 113), however, the OR of the C/T genotype for gastric cancer was significant (OR = 2.02, 95% CI: 1.04-3.92) relative to the C/C genotype. In addition, considering the location of gastric cancer (n = 105), there were significant differences between the controls and non-cardia group with the OR of 2.13 (95% CI: 1.08-4.18) for C/T and 1.94 (95% CI: 1.00-3.78) for C/T + T/T.

CONCLUSION: The iNOS C150T polymorphism is associated with the risk of H pylori-related gastric cancer in a Japanese population. This polymorphism may play an important role in increasing the risk of gastric cancer in Asian countires with the highest rates of gastric cancer.