Lack of glycemic control in type two diabetes mellitus patients is associated with reduced serum epidermal growth factor level and increased insulin resistance

The prevalence of type 2 diabetes mellitus (T2DM) is steadily increasing worldwide in an alarming fashion. Importantly, poor glycemic control is associated with development of various health sequalae's due to glucolipotoxicity, oxidative stress and increased inflammatory cytokines. The aim of the present study was to examine the effect of glycemic control on the relative abundance of inflammatory markers in patients with controlled and uncontrolled T2DM, and to test their association with the glycemic status in diabetic patients in Jordan. An observational cross-sectional study design was used. Patients with T2DM with controlled diabetes [glycated hemoglobin (HbA1c) ≤7.0%, n=110] and age-, sex- and body mass index (BMI)-matched uncontrolled diabetic patients (HbA1c >7.0%, n=105) were recruited. An antibody membrane array was used to examine the relative abundance of inflammatory cytokines and growth factors in the sera of the study subjects, followed by enzyme-linked immunosorbent assay (ELISA) to confirm the results. Fasting blood glucose, serum insulin, triglyceride and homeostatic model assessment for insulin resistance (HOMA-IR) score were significantly elevated in the uncontrolled T2DM group (P<0.05). Antibody membrane array showed that serum epidermal growth factor (EGF) is significantly decreased in the uncontrolled T2DM group, and this was confirmed by ELISA (158.77±111.7 vs. 95.9±82.7 pg/ml, P=0.002). The binary logistic model was used to predict the likelihood of being uncontrolled diabetic based on EGF levels. After controlling for age, sex and BMI, EGF was statistically associated with diabetes control, where lower EGF levels predicted uncontrolled diabetes. Additionally, Pearson's product-moment correlation showed a statistically significant negative correlation between EGF and HbA1c (r=-0.25, P<0.0001), and a positive correlation between HOMA-IR and HbA1c, (r=0.32, P<0.0001). The current data identify a novel link between serum EGF levels and the status of HbA1c indicative of diabetic control.

Assessing the diagnostic value of serum Dickkopf-related protein 1 levels in cancer detection: a case-control study and meta-analysis

BACKGROUND

This study aimed to summarize the potential diagnostic value of serum DKK1 levels in cancer detection.

MATERIALS AND METHODS

Serum DKK1 was measured using enzyme-linked immunosorbent assay in a case-control study. Then we performed a meta-analysis and the pooled sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic (sROC) curves were used to evaluate the overall test performance.

RESULTS

Serum DKK1 levels were found to be significantly upregulated in gastric cancer as compared to controls. ROC curve analysis revealed an AUC of 0.636, indicating the test has the potential to diagnose cancer with poor accuracy. The summary estimates of the pooled sensitivity, specificity and diagnostic odds ratio in meta-analysis were 0.55 with a 95% confidence interval (CI) (0.53-0.57), 0.86 (95%CI, 0.84-0.88) and 12.25 (95%CI, 5.31-28.28), respectively. The area under the sROC was 0.85. Subgroup analysis revealed that the diagnostic accuracy of serum DKK1 in lung cancer (sensitivity: 0.69 with 95%CI, 0.66-0.74; specificity: 0.95 with 95%CI, 0.92-0.97; diagnostic odds ratio: 44.93 with 95%CI, 26.19-77.08) was significantly higher than for any other cancer.

CONCLUSIONS

Serum DKK1 might be useful as a noninvasive method for confirmation of cancer diagnosis, particularly in the case of lung cancer.

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.

Profile of erlotinib and its potential in the treatment of advanced ovarian carcinoma

The epidermal growth-factor receptor (EGFR) is overexpressed in the majority of epithelial ovarian cancers and promotes cell proliferation, migration and invasion, and angiogenesis, as well as resistance to apoptosis. This makes EGFR an attractive therapeutic target in this disease. A number of strategies to block EGFR activity have been developed, including small-molecular-weight tyrosine kinase inhibitors such as erlotinib. Erlotinib has been evaluated as a single agent in recurrent ovarian cancer, as well as in combination with chemotherapeutic agents in the first-line and recurrent settings, and in combination with the antiangiogenic agent bevacizumab in the recurrent setting, as well as in the maintenance setting after completion of first-line chemotherapy. Unfortunately, erlotinib has shown only minimal efficacy as a single agent, and it has not enhanced the effects of chemotherapy or bevacizumab when combined with these agents. Ongoing and future studies of erlotinib and other agents blocking EGFR will need to define mechanisms resulting in resistance to such interventions, and to validate biomarkers of response to identify patients most likely to benefit from such approaches.

Functional single-nucleotide polymorphism of epidermal growth factor is associated with the development of Barrett's esophagus and esophageal adenocarcinoma

Reflux esophagitis (RO) and Barrett's esophagus (BO) can cause esophageal adenocarcinoma (OAC). The esophageal mucosa in the RO-BO-OAC cascade is chronically exposed to gastro-esophageal reflux. Epidermal growth factor (EGF) has an important role in the protection and repair of mucosal damage, and non-physiologic levels are associated with gastrointestinal tumors. The aim is to determine the functional effect of EGF gene polymorphisms on RO, BO and OAC development. A cohort of 871 unrelated Dutch Caucasians consisted of 198 healthy controls, 298 RO patients, 246 BO patients and 129 OAC patients. The frequency of the EGF-production-associated 5'UTR A+61G polymorphism was determined in these four groups. EGF immunohistochemistry was performed on BO biopsies. EGF expression was significantly lower in the G/G genotype compared with the A/G (P=0.008) and A/A (P=0.002) group. The G/G genotype was significantly more prevalent in RO (odds ratios (OR)=2.6; 95% confidence intervals (95% CI): 1.3-5.2), BO (OR=3.0; 95% CI: 1.5-6.2) and OAC (OR=4.1; 95% CI: 1.8-9.7) than in controls. The G allele is associated with reduced EGF expression and increased risk for RO, BO and OAC development. This indicates that reduced mucosal protection resulting from genetically decreased EGF expression enhances esophageal tumor development.

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.

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.

Epidermal growth factor +61 G/A polymorphism and the risk of hepatocellular carcinoma in a Chinese population

BACKGROUND

Chronic hepatitis B virus (HBV) infection is a risk factor of hepatocellular carcinoma (HCC) in China. Epidermal growth factor (EGF) plays an important role in tumorigenesis. The association between EGF +61 G/A polymorphism and the risk of HCC is still controversial and ambiguous.

AIM

The objective of this study was to investigate the association between EGF +61 G/A polymorphism and the risk of HCC in a Chinese population.

METHODS

A hospital-based case-control study was designed in a Chinese population. EGF +61 G/A polymorphisms were determined in 120 chronic HBV-infected HCC patients, 120 chronic HBV-infected cirrhotic patients, and 120 healthy controls. The genotype frequency of this polymorphism was determined by using a polymerase chain reaction-restriction fragment length polymorphism assay.

RESULTS

EGF +61 GG (odds ratio=2.76, 95% confidence interval=1.03, 7.38; p=0.04) and G allele frequencies (odds ratio=1.59, 95% confidence interval=1.08, 2.34; p=0.02) in the HCC group were higher than those in the cirrhosis group. EGF +61 A and G allele frequencies in healthy subjects were 28.8% and 71.2%. No relationship between EGF +61 G/A gene polymorphism and HCC risk was found among our recruited HCC patients and healthy controls.

CONCLUSION

This study suggests that EGF +61 GG genotype is associated with a higher risk of chronic HBV-infected HCC in the Chinese population.

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.

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.

EGFR pathway polymorphisms and bladder cancer susceptibility and prognosis

The epidermal growth factor receptor (EGFR) pathway has recently been appreciated as a central mediator of tumorigenesis and an important drug target; however, the influence of genetic variation in this pathway on bladder cancer is not understood. Pathway activation leads to cell proliferation, angiogenesis and is antiapoptotic. We sought to test the hypothesis that bladder cancer susceptibility and survival are modified by inherited variations in the sequence of the EGFR and its pathway members. We tested associations using a population-based study of 857 bladder cancer cases and 1191 controls from New Hampshire. Multifactor dimensionality reduction software was used to predict gene-gene interactions. We detected an increased risk of bladder cancer associated with variant genotypes for the single nucleotide polymorphisms EGFR_03 [adjusted odds ratio (OR) 1.7 (95% confidence interval (CI) 1.0-2.8)] and EGFR_05 [adjusted OR 1.5 (95% CI 1.0-2.1)] compared with wild-type. EGFR variants experienced longer survival than those with wild-type alleles [e.g. adjusted hazard ratio EGFR_1808 0.3 (95% CI 0.1-0.9)]. In contrast, the variant form of the ligand, EGF_04, had worse survival [adjusted hazard ratio 1.5 (95% CI 1.0-2.3)] compared with wild-type. Our findings suggest modified bladder cancer risk and survival associated with genetic variation in the EGFR pathway. Understanding these genetic influences on increased bladder cancer susceptibility and survival may help in cancer prevention, drug development and choice of therapeutic regimen.