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

EGF rs4444903 polymorphism is associated with risk of HCV-related cirrhosis and HBV/HCV-related hepatocellular carcinoma

OBJECTIVE

The epidermal growth factor (EGF) rs4444903 polymorphism is associated with aberrant expression of EGF, which was a characteristic of cirrhotic liver diseases, induces highly malignant hepatocellular carcinoma (HCC). Numerous studies have uncovered the association of this polymorphism with the risk of liver disease, but with inconsistent findings.

MATERIALS AND METHODS

Therefore, this meta-analysis was performed to evaluate whether EGF rs4444903 polymorphism conferred susceptibility to liver disease. Totally 18 eligible articles were identified by searching PubMed, Google, CNKI and EMBASE up to December 1, 2020.

RESULTS

Our results indicated that there was no significant difference in the minor G allele frequency of rs4444903 polymorphism between HBV/HCV carriers and healthy controls. In other words, EGF rs4444903 polymorphism was not associated with the risk of HBV/HCV. Interestingly, this polymorphism increased the risk of liver cirrhosis in the controls with HCV infection. Additionally, EGF rs4444903 polymorphism is associated with the increased risk of HCC under the five models. Subgroup analysis by ethnicity shows that rs4444903 polymorphism intensifies the risk of HCC among Asians and Caucasians. Strong correlation is also reported in controls with cirrhosis or HCV infection and studies using PCR-RFLP genotyping.

CONCLUSIONS

The study supports that EGF rs4444903 polymorphism is a genetic contributor to liver cirrhosis and HCC in the overall population. Nevertheless, this conclusion must be confirmed by larger studies with more diverse ethnic populations.

Association of the epidermal growth factor gene +61A>G polymorphism with hepatocellular carcinoma in an Iranian population

AIM

The aim of this study was to address the association of the EGF gene +61A/G polymorphisms and HCC susceptibility in an Iranian population.

BACKGROUND

The association of epidermal growth factor (EGF) gene +61A/G polymorphism (rs4444903) and hepatocellular carcinoma (HCC) has been investigated in several populations. However, the findings are controversial.

METHODS

A total of 40 unrelated HCC patients and 106 healthy individuals were enrolled in this study. Genomic DNA of HCC patients was extracted from formalin-fixed, paraffin-embedded samples using CinnaPure DNA kit according to manufacturer's instructions. Genomic DNA of healthy individuals, also, was extracted from peripheral blood cells using the boiling method. The rs4444903 (A/G) polymorphism was genotyped using the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method.

RESULTS

Significant association was found for the EGF +61A allele and HCC risk [OR = 1.72, 95% CI (1.02 - 2.90), P value = 0.04]. Also, significant association was observed for the EGF +61A/G genotypes and HCC risk under codominant and dominant models by SNPStats software analysis.

CONCLUSION

Our findings suggest that the EGF gene +61A/G polymorphism (rs4444903) might be a risk factor for susceptibility to HCC in Iranian population. However, further studies using more samples are needed.

Association between the epidermal growth factor 61*A/G polymorphism and hepatocellular carcinoma risk: a meta-analysis

The epidermal growth factor (EGF) may play a pathological role in hepatocellular carcinoma (HCC). However, the conclusions of published reports on the relationship between the EGF 61*A/G polymorphism and HCC risk remain controversial. To derive a more precise estimation we performed a meta-analysis based on 14 studies that together included 2,506 cases and 4,386 controls. PubMed, EMBASE, Web of Knowledge and the Chinese National Knowledge Infrastructure (CNKI) databases were used to retrieve articles up to August 1, 2014. The crude odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to evaluate the association. Meta-analysis results showed a significant association between the EGF 61*A/G polymorphism and HCC risk in all four genetic models (allele model: OR=1.25, 95%CI=1.12-1.40; dominant model: OR=1.32, 95%CI=1.14-1.54; recessive model: OR=1.33, 95%CI=1.12-1.58; homozygous model: OR=1.59, 95%CI=1.33- 1.90). Moreover, significant associations were observed when stratified by ethnicity, source of controls, etiology and genotype methods. Thus, this meta-analysis suggests that the G-allele of the EGF 61*A/G polymorphism is associated with an increased risk of HCC, especially in Asians and Caucasians, without influence from the source of controls or etiological diversity. Further studies with larger population sizes are needed to confirm these results.

Quantitative assessment of the effect of epidermal growth factor 61A/G polymorphism on the risk of hepatocellular carcinoma

The association between hepatocellular carcinoma (HCC) and the epidermal growth factor (EGF) 61A/G polymorphism has been analyzed in several studies, but results remain inconsistent. Therefore, the aim of the present study was to quantitatively summarize the association between the EGF 61A/G polymorphism and the risk of HCC. The PubMed and EMBASE databases were searched for studies published prior to May 1, 2014. The overall, subgroup and sensitivity analyses were conducted using Comprehensive Meta-Analysis software, version 2.2. In total, 12 published case-control studies, consisting of 2,095 patients with HCC and 3,766 control individuals, were included in the present study. Meta-analysis of the included studies revealed that EGF 61A/G polymorphism contributed to the risk of HCC under all four genetic models, consisting of the G vs. A (OR, 1.25; 95% CI, 1.11-1.40), GG vs. AA (OR, 1.53; 95% CI, 1.26-1.85), GG vs. AG + AA (OR, 1.34; 95% CI, 1.13-1.58) and GG + AG vs. AA (OR, 1.27; 95% CI, 1.08-1.49) comparisons. Subgroup analysis further suggested that EGF 61A/G polymorphism was associated with the risk of HCC in patients and control individuals with liver disease, based on ethnicity and source of control, respectively. No other significance in residual subgroup analysis was observed. The present meta-analysis suggests that the EGF 61A/G polymorphism is associated with an increased risk of HCC and may be a potential marker for liver disease, such as hepatitis B virus infection, hepatitis C virus infection and liver cirrhosis.

Polymorphism in epidermal growth factor is related to clinical outcomes of metastatic colorectal cancer patients treated with cetuximab: a systematic review and meta-analysis

Numerous studies focusing on genetic variants in order to find cetuximab subpopulation biomarkers have emerged, yet the significance of each biomarker is diverse. Based on these results, we carried out a meta-analysis to assess the correlation between epidermal growth factor (EGF) A61G polymorphism and clinical outcomes of metastatic colorectal cancer (mCRC) patients treated with cetuximab. We aim to prove that EGF polymorphisms may be potential biomarkers for cetuximab therapeutic strategies. We identified 6 previously published studies including 569 patients treated with cetuximab-based regimens. Outcomes included clinical response, progression-free survival (PFS), and overall survival (OS). GG homozygote showed association with better response rates (GG vs. AA+AG, OR = 2.82; 95% CI = 1.58-5.04) and than AA+AG genotypes. This meta-analysis showed that mCRC patients harboring GG genotype of EGF A61G polymorphism inclined to have a better response rate with cetuximab treatment.

Epidermal growth factor receptor pathway polymorphisms and the prognosis of hepatocellular carcinoma

The EGFR signaling pathway is important in the control of vital processes in the carcinogenesis of hepatocellular carcinoma (HCC), including cell survival, cell cycle progression, tumor invasion and angiogenesis. In the current study, we aim to assess if genetic variants in the genes of the EGFR signaling pathway are associated with the prognosis of HCC. We genotyped 36 single nucleotide polymorphisms (SNP) in four core genes (EGF, EGFR, VEGF, and VEGFR2) by using DNA from blood samples of 363 HCC patients with surgical resection. The associations between genotypes and overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Hazard ratios (HRs) and 95% confident intervals (CIs) were estimated for the multivariate survival analyses by Cox proportional hazards regression models, adjusting for age, gender, family history, HBsAg and AFP. We found that five SNPs in the VEGFR2 gene were significantly associated with clinical outcomes of HCC patients. Among them, four SNPs (rs7692791, rs2305948, rs13109660, rs6838752) were associated with OS (p=0.035, 0.038, 0.029 and 0.028, respectively), and two SNPs (rs7692791 and rs2034965) were associated with DFS (p=0.039 and 0.017, respectively). Particularly, rs7692791 TT genotype was associated with both reduced OS (p=0.037) and DFS (p=0.043). However, only one SNP rs2034965 with the AA genotype was shown to be an independent effect on DFS (p=0.009) in the multivariate analysis. None of the other 31 polymorphisms or 9 haplotypes attained from the four genes was significantly associated with OS or DFS. Our results illustrated the potential use of VEGFR2 polymorphisms as prognostic markers for HCC patients.

Host genetics predict clinical deterioration in HCV-related cirrhosis

Single nucleotide polymorphisms (SNPs) in the epidermal growth factor (EGF, rs4444903), patatin-like phospholipase domain-containing protein 3 (PNPLA3, rs738409) genes, and near the interleukin-28B (IL28B, rs12979860) gene are linked to treatment response, fibrosis, and hepatocellular carcinoma (HCC) in chronic hepatitis C. Whether these SNPs independently or in combination predict clinical deterioration in hepatitis C virus (HCV)-related cirrhosis is unknown. We genotyped SNPs in EGF, PNPLA3, and IL28B from liver tissue from 169 patients with biopsy-proven HCV cirrhosis. We estimated risk of clinical deterioration, defined as development of ascites, encephalopathy, variceal hemorrhage, HCC, or liver-related death using Cox proportional hazards modeling. During a median follow-up of 6.6 years, 66 of 169 patients experienced clinical deterioration. EGF non-AA, PNPLA3 non-CC, and IL28B non-CC genotypes were each associated with increased risk of clinical deterioration in age, sex, and race-adjusted analysis. Only EGF non-AA genotype was independently associated with increased risk of clinical deterioration (hazard ratio [HR] 2.87; 95% confidence interval [CI] 1.31-6.25) after additionally adjusting for bilirubin, albumin, and platelets. Compared to subjects who had 0-1 unfavorable genotypes, the HR for clinical deterioration was 1.79 (95%CI 0.96-3.35) for 2 unfavorable genotypes and 4.03 (95%CI 2.13-7.62) for unfavorable genotypes for all three loci (Ptrend<0.0001). In conclusion, among HCV cirrhotics, EGF non-AA genotype is independently associated with increased risk for clinical deterioration. Specific PNPLA3 and IL28B genotypes also appear to be associated with clinical deterioration. These SNPs have potential to identify patients with HCV-related cirrhosis who require more intensive monitoring for decompensation or future therapies preventing disease progression.

Hepatitis C virus-associated cancer

Hepatitis C virus (HCV) is one of the major etiologic agents of liver cancer. HCV is an RNA virus that, unlike hepatitis B virus, is unable to integrate into the host genome. Through complex interactions between viral and host proteins that induce host responses and promote inflammation, fibrosis, and ultimately cirrhosis, HCV infection can result in the development of hepatocellular carcinoma (HCC). The HCV oncogenic process involves genetic and epigenetic alterations and oncogenic effects mediated by viral proteins in the activation of cellular oncogenes, inactivation of tumor-suppressor genes, and dysregulation of multiple signal-transduction pathways. Advances in genetics and gene expression profiling have enhanced our current understanding of the pathways involved in HCV-associated liver cancer development. In this review, we summarize the current understanding of mechanisms of hepatocarcinogenesis induced by HCV infection.

Epidermal growth factor, from gene organization to bedside

In 1962, epidermal growth factor (EGF) was discovered by Dr. Stanley Cohen while studying nerve growth factor (NGF). It was soon recognized that EGF is the prototypical member of a family of peptide growth factors that activate the EGF receptors, and that the EGF/EGF receptor signaling pathway plays important roles in proliferation, differentiation and migration of a variety of cell types, especially in epithelial cells. After the basic characterization of EGF function in the first decade or so after its discovery, the studies related to EGF and its signaling pathway have extended to a broad range of investigations concerning its biological and pathophysiological roles in development and in human diseases. In this review, we briefly describe the gene organization and tissue distribution of EGF, with emphasis on its biological and pathological roles in human diseases.

Polymorphism of ERCC2 Asp312Asn with lung cancer risk: evidence from 20,101 subjects

The association between excision repair cross complementing group 2 (ERCC2) Asp312Asn polymorphism and lung cancer has been reported by many articles recently, but the results were controversial and inconclusive. Therefore, a meta-analysis was conducted to assess the relationship between them. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. A total of 22 full studies with 20,101 subjects (8719 cases and 11,382 controls) were included in our research. The meta-analysis result showed that no significant association was found between ERCC2 Asp312Asn polymorphism and lung cancer in overall analysis (AA vs. GG, OR=1.023, 95% CI=0.824-1.270, p=0.838; AG vs. GG, OR=1.003, 95% CI=0.936-1.074, p=0.942; AA+AG vs. GG, OR=1.013, 95% CI=0.949-1.082, p=0.697; AA vs. AG+GG, OR=1.033, 95% CI=0.841-1.270, p=0.755). In subset analyses of stratified ethnicity, significantly increased risk was found among Asians (AA vs. GG, OR=3.212, 95% CI=1.518-6.795, p=0.002; AA vs. AG+GG, OR=3.174, 95% CI=1.500-6.712, p=0.003), whereas the association was not found among Caucasians under any genetic models. When analyses were conducted based on the study design, it indicated that the risk of lung cancer might be significantly increased in a hospital-based study (AA vs. GG, OR=1.323, 95% CI=1.096-1.596, p=0.004; AA+AG vs. GG, OR=1.109, 95% CI=1.000-1.229, p=0.050; AA vs. AG+GG, OR=1.285, 95% CI=1.076-1.535, p=0.006). In addition, a significantly increased risk for nonsmokers was detected under the dominant model (AA+AG vs. GG, OR=1.460, 95% CI=1.095-1.948, p=0.010). In conclusion, this meta-analysis suggested ERCC2 Asp312Asn polymorphism may increase the risk of lung cancer among Asians, whereas not among Caucasians.

A functional polymorphism in the epidermal growth factor gene predicts hepatocellular carcinoma risk in Japanese hepatitis C patients

BACKGROUND

A single nucleotide polymorphism (SNP) in the epidermal growth factor (EGF) gene (rs4444903) has been associated with increased risk of cancer, including hepatocellular carcinoma (HCC). The aim of this study was to examine the relationship between the EGF SNP genotype and the development and prognosis of HCC, in a Japanese population.

METHODS

Restriction fragment-length polymorphism was used to determine the presence of the EGF SNP genotype in 498 patients, including 208 patients with HCC. The level of EGF messenger ribonucleic acid (mRNA) expression in cancerous tissues was measured by quantitative reverse transcription polymerase chain reaction. The correlation between the EGF SNP genotype and prognosis was statistically analyzed in the patients with HCC.

RESULTS

The proportion of the A/A, A/G, and G/G genotypes were 5.3%, 42.8%, and 51.9%, respectively, in the patients with HCC, whereas in those without HCC, they were 8.6%, 35.9%, and 55.5%, respectively, revealing that the odds ratio (OR) of developing HCC was higher in patients with a G allele (OR =1.94, P=0.080 for A/G patients and OR =1.52, P=0.261 for G/G patients, as compared with A/A patients). In particular, when the analysis was limited to the 363 patients with hepatitis C, the OR for developing HCC was 3.54 (P=0.014) for A/G patients and was 2.85 (P=0.042) for G/G patients, as compared with A/A patients. Tumoral EGF mRNA expression in G/G patients was significantly higher than that in A/A patients (P=0.033). No statistically significant differences were observed between the EGF SNP genotype and diseasefree or overall survival.

CONCLUSION

The EGF SNP genotype might be associated with a risk for the development of HCC in Japanese patients but not with prognosis. Of note, the association is significantly stronger in patients with hepatitis C, which is the main risk factor for HCC in Japan.