Relationship between genetic polymorphism of glutathione S-transferase-p1 and p53 protein accumulation in Iranian esophageal squamous cell carcinoma patients

No role for glutathione S-transferase genotypes in Caucasian esophageal squamous cell or adenocarcinoma etiology: an European case-control study

BACKGROUND

Identifying and monitoring high-risk patients can aid the prevention of esophageal cancer (EC). The interaction of environmental risk factor exposure and genetic susceptibility may contribute to the etiology of EC. Biotransformation enzymes such as Glutathione S-Transferases (GSTs ) detoxify mutagenic and genotoxic compounds and therefore control the rate of detoxification of carcinogens. Functional polymorphisms in the genes coding for GSTs alter their enzyme activity in vitro, and were reported to modify EC risk in Asians. We hypothesized that altered enzyme activity GST genotypes influence the susceptibility for esophageal adeno- (EAC) and squamous cell carcinoma (ESCC) in Caucasians.

METHODS

We performed a case-control study including 440 Caucasian patients with EC and 592 healthy Caucasian controls matched for age and sex. Functional polymorphisms were selected and genotypes were determined in GST classes Alpha, Mu, Theta and Pi by means of polymerase chain reaction. Genotypes were classified into predicted high, intermediate and low enzyme activity categories based on in vitro activity data. The distribution of the activity genotypes were compared between patients with EAC or ESCC, and controls. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by logistic regression analyses. Gene-gene interactions were tested and for comparison purposes, the predicted low and intermediate activity genotypes were combined. Genotypes with similar risks for EAC or ESCC were combined and analyzed for multiplicative effects.

RESULTS

Our analyses includes 327 patients with EAC and 106 patients with ESCC. Low or intermediate activity enzyme genotypes for GSTM1, GSTA1, GSTP1 I105V and A114V as well as for GSTT1, did not significantly modify the risk for ESCC or EAC in our Dutch population.

CONCLUSION

Functional genotypes in GST genes are not involved in EAC or ESCC susceptibility in Caucasians, in contrast to results on ESCC from Asia or Africa.

Study on the association of p53 codon 72 polymorphisms with risk of gastric cancer in high incidence Hexi area of Gansu Province in China

To investigate the possible association of P53 codon 72 Arg/Pro polymorphisms with risk of gastric cancer in the high incidence Hexi area of Gansu province in China. Blood samples from 140 patients with gastric carcinoma and 125 healthy controls were collected in Hexi area of Gansu province. Polymorphism of P53Arg72Pro was genotyped by PCR-TaqMan. For detection Helicobacter pylori infection, Warhin-Starry staining was used. Three kinds of polymorphisms of P53Arg72Pro were Arg/Arg, Arg/Pro, Pro/Pro. The frequencies in gastric cancer group were 15.7, 60.0, 24.3%, and the frequencies in healthy controls were 25.6, 54.4, 20.0%, respectively. P53 codon 72 Pro carrier genotype (Arg/Pro+Pro/Pro) increased risk of gastric carcinoma with an odds ratio 1.840 (95% CI: 1.006-3.387). Helicobacter pylori infection rate was 68.6% in patients group and 50.4% in healthy controls. Helicobacter pylori infection rate in gastric cancer patients was remarkably higher than that in the controls (OR: 2.147, 95% CI: 1.302-3.541, P=0.003). Stratification analysis showed that P53 codon 72 Pro carrier genotype with Helicobacter pylori infection was significantly higher in cases than that in the controls (OR: 4.182, 95% CI: 1.850-9.454). P53Arg72Pro polymorphisms could be a risk factor for gastric cancer in high incidence Hexi area of Gansu Province in China. P53 codon 72 Pro carrier genotype and Helicobacter pylori positive infection may have a synergistic effect on gastric cancer in high incidence Hexi area of Gansu Province in China.

Elevated levels of urinary 8-hydroxy-2'-deoxyguanosine and 8-isoprostane in esophageal squamous cell carcinoma

Aims:

To measure oxidative DNA and lipid damages, urinary levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), and 8-isoprostane in esophageal squamous cell carcinoma (SCC) patients and compare the values with that in controls.

Materials and Methods:

The urinary concentrations of 8-OHdG and 8-isoprostane were measured in 32 SCC patients (13 female/19 male; mean age: 61.4 ± 10.5 years) and 45 controls (22 female/23 male; mean age: 58.1 ± 8.3 years).

Results:

Squamous cell carcinoma patients showed significantly higher levels of urinary 8-OHdG (15.6 ± 5.1 ng/mg creatinine) than controls (5.8 ± 2.1 ng/mg creatinine) (P<.001). Increased urinary concentrations of 8-isoprostane were also detected in SCC patients (35.4 ± 6.5 ng/mmol creatinine) as compared to the controls (16.9 ± 4.0 ng/mmol creatinine) (P<.001).

Conclusions:

Our results show the presence of oxidative DNA and lipid damage in the SCC patients. This may have a connection to carcinogenesis in the esophagus.

Study the polymorphism of CYP3A5 and CYP3A4 loci in Iranian population with laryngeal squamous cell carcinoma

Cancer reflects a complicated network of interactions between genes and environmental factors. Cytochrome P450 (CYP) is a multi-gene superfamily participating in the metabolism of xenobiotics. The aim of our study was to examine whether polymorphisms in the CYP enzyme genes affect the risk of developing larynx squamous cell carcinoma (SCC). Polymorphism of CYP3A5 and CYP3A4 genes were investigated in 50 patients with laryngeal SCC and 100 control subjects by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). In patients the CYP3A5 3/3 and 1/3genotypes were detected in 92% and 8% respectively. There was no relation between genotype, allele frequency and grade/stage of tumor. In control group, the frequency of CYP3A5 3/3 and CYP3A5 1/3 genotype were 98% and 2% respectively. There was no significant difference in genotype and allele frequency of this gene between patient and control group. In respect of CYP3A41A/B, people in both patient and control groups had the same genotype of CYP3A41A/1A. In this study, the CYP gene variants were not associated with increased risk of laryngeal SCC. Study on the other genetic factors which are involved in activation/detoxication of procarcinogenes, such as CYP1A1, CYP1B1, CYP2E1 and gluthation S transferase is recommended.

Expression of mutant p53 and of the multidrug resistant proteins P-glycoprotein and glutathione S-transferase-pi correlated in colorectal adenocarcinoma

OBJECTIVE

Accumulating studies suggest that multidrug resistance is related to expression of p53, P-glycoprotein (Pgp) and Glutathione S-Transferase-pi (GST-pi). This study was to estimate mutant p53 expression and its correlation with drug resistance related proteins Pgp and GST-pi expression in colorectal adenocarcinoma patients.

MATERIAL AND METHODS

Immunohistochemical ABC technique was used to detect the expression of mutant p53 protein, Pgp and GST-pi in 404 cases with colorectal adenocarcinoma.

RESULTS

A low frequency of mutant p53 accumulation was observed, consistent with findings in colorectal cancers (CRCs) from other Asian populations. Accumulation of mutant p53 was related to AJCC staging (p < 0.05). Pgp expression was significantly correlated with tumor location (p = 0.039) and gender (p = 0.043). The positive percentage of Pgp and GST-pi expression was all significantly higher in mutant p53 protein positive group than mutant p53 protein negative cases (r = 0.634, p < 0.001 and r = 0.680, p < 0.001, respectively).

CONCLUSIONS

These findings demonstrate association of three biomarkers with clinicopathologic parameters of colorectal carcinoma, and overexpression of Pgp and GST-pi was closely correlated with mutant p53.

Genetic association of phase I and phase II detoxification genes with recurrent miscarriages among North Indian women

Allelic variants of the detoxification genes that have impaired biotransformation functions may increase susceptibility to reproductive toxicity leading to endometriosis, recurrent miscarriage (RM) or poor pregnancy outcome. In the present study, we have investigated CYP1A1, CYP2D6, GSTT1, GSTP1 and GSTM1, which are involved in the phase I and phase II detoxification systems, in relation to their role in the etiology of unexplained RMs. In a case-control study, we have investigated 200 females with RM and 300 age and ethnically matched healthy controls with successful reproductive history from North India. The frequencies of phase I wild-type genotypes of CYP1A1 and CYP2D6 in RM cases were 0.56 and 0.60, whereas in controls these were 0.68 and 0.65, respectively (both P < 0.05). The GSTM1 null-genotype frequencies were 0.66 and 0.84 among RM cases and controls, respectively, the GSTT1 null-genotype frequencies were 0.52 and 0.45 (P < 0.005) and the GSTP1 variant allele frequencies were 0.23 and 0.20, respectively. In conclusion, we observed significant protective effects of phase I wild-type genotypes and association of the GSTT1 null genotype with RM. Through combined analyses we have highlighted the importance of the balance of phase I/phase II detoxification systems, in the etiology of RM.

Polymorphism Arg290Arg in esophageal-cancer-related gene 1 (ECRG1) is a prognostic factor for survival in esophageal cancer

BACKGROUND

Esophageal cancer is one of the most frequent cancers worldwide and is associated with poor outcome. Besides clinicopathological data, few prognostic molecular markers exist. Esophageal-cancer-related gene1 (ECRG1) short tandem repeats are associated with higher risk for developing esophageal squamous cell carcinoma. The aim of the present study was to evaluate the impact of DNA polymorphisms in the coding region of ECRG1 in esophageal carcinoma.

METHODS

Genomic DNA of 107 patients with esophageal cancer that underwent complete surgical resection between 1997 and 2005 was extracted. DNA was analyzed for ECRG1 polymorphisms Arg290Arg, Arg290Gln, and Gln290Gln by PCR and gel electrophoresis. Polymorphisms were correlated with survival data by the Kaplan-Meier method, multivariate Cox regression analysis, and odds ratio were determined. For all variables, cross tables were generated, followed by calculation of the p value by using the chi-square test/Fisher-exact test.

RESULTS

Follow-up data of 102 patients with esophageal cancer were available after complete surgical resection for a median follow-up time of 24.3 months. Polymorphism Arg290Arg was found in 47 patients (46.1%), Arg290Gln in 48 patients (47.0%), and Gln290Gln in seven cases (6.9%). Arg290Arg polymorphism was significantly associated with reduced overall survival (p = 0.01) and tumor-free survival (p = 0.01) by the log-rank test. Multivariate regression analysis by Cox revealed polymorphism Arg290Arg to be a significant prognostic factor for survival (p = 0.012).

CONCLUSIONS

Polymorphism Arg290Arg in ECRG1 is associated with poor clinical outcome after complete surgical resection in patients with esophageal cancer.