Association between N142D genetic polymorphism of GSTO2 and susceptibility to colorectal cancer. Mol Biol Rep. 2011;38:4309-4313. [PMID: 21113667 DOI: 10.1007/s11033-010-0555-7]

The Polymorphisms in GSTO Genes (GSTO1 rs4925, GSTO2 rs156697, and GSTO2 rs2297235) Affect the Risk for Testicular Germ Cell Tumor Development: A Pilot Study

Members of the omega class of glutathione transferases (GSTs), GSTO1, and GSTO2, catalyze a range of reduction reactions as a part of the antioxidant defense system. Polymorphisms of genes encoding antioxidant proteins and the resultant altered redox profile have already been associated with the increased risk for testicular germ cell cancer (GCT) development. The aim of this pilot study was to assess the individual, combined, haplotype, and cumulative effect of GSTO1rs4925, GSTO2rs156697, and GSTO2rs2297235 polymorphisms with the risk for testicular GCT development, in 88 patients and 96 matched controls, through logistic regression models. We found that carriers of the GSTO1*C/A*C/C genotype exhibited an increased risk for testicular GCT development. Significant association with increased risk of testicular GCT was observed in carriers of GSTO2rs2297235*A/G*G/G genotype, and in carriers of combined GSTO2rs156697*A/G*G/G and GSTO2rs2297235*A/G*G/G genotypes. Haplotype H7 (GSTO1rs4925*C/GSTO2rs2297235*G/GSTO2rs156697*G) exhibited higher risk of testicular GCT, however, without significant association (p > 0.05). Finally, 51% of testicular GCT patients were the carriers of all three risk-associated genotypes, with 2.5-fold increased cumulative risk. In conclusion, the results of this pilot study suggest that GSTO polymorphisms might affect the protective antioxidant activity of GSTO isoenzymes, therefore predisposing susceptible individuals toward higher risk for testicular GCT development.

The Upregulation of GSTO2 is Associated with Colon Cancer Progression and a Poor Prognosis

Colorectal cancer is the second-leading cause of cancer-related mortality in the United States. Glutathione S-transferase can affect the development of cancer. Glutathione S-transferase omega 2, a member of the GST family, plays an important role in many tumors. However, the role of Glutathione S-transferase omega 2 in the development of colon cancer remains unclear. Herein, our study aimed to investigate the exact role of Glutathione S-transferase omega 2 in colon cancer. We used RNA sequencing data from The Cancer Genome Atlas and the Genotype-Tissue Expression database to analyze Glutathione S-transferase omega 2 expressions. Then, we explore the protein information of Glutathione S-transferase omega 2 in the Human Protein Atlas, GeneCards, and String database. In addition, western blot and immunohistochemistry were performed to evaluate the protein levels of Glutathione S-transferase omega 2 in colon cancer tissues. We acquire data from the Gene Expression Omnibus and The Cancer Genome Atlas databases. Also, we performed relevant prognostic analyses of these data. In addition, we performed a statistical analysis of the clinical data from The Cancer Genome Atlas database and the expression level of Glutathione S-transferase omega 2. Then, we performed Cox regression analysis and found independent risk factors for prognosis in patients with colon cancer. The Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses were used to explore the potential biological functions of Glutathione S-transferase omega 2. The infiltration of colon cancer-immune cells was evaluated by the CIBERSORT method. RNA silencing was performed using siRNA constructs in HCT-116 and HT-29 cell lines. Cell Counting Kit-8 and EdU assays were performed to determine cell proliferation. Transwell experiments and scratch tests were used to determine cell migration. As for the mRNA and protein expression levels of cells, we used quantitative real-time PCR and western blot to detect them. Our research shows that Glutathione S-transferase omega 2 is overexpressed in colon cancer patients, and this overexpression is associated with a poor prognosis. The high expression of Glutathione S-transferase omega 2 is significantly correlated stage with stage, M, and N classification progression in colon cancer by statistical analysis. Univariate and multivariate Cox regression analyses showed that Glutathione S-transferase omega 2 was an independent risk factor for poor prognosis in colon cancer. In addition, we also found that Glutathione S-transferase omega 2 expression levels can affect the immune microenvironment of colon cancer cells. Gene silencing of Glutathione S-transferase omega 2 in HT-29 and HCT-116 cells significantly inhibited tumor growth and migration. In summary, we found that Glutathione S-transferase omega 2 can be used as a molecular indicator of colon cancer prognosis. In vitro, gene silencing of Glutathione S-transferase omega 2 inhibited colon cancer cells' growth and migration.

Useful genes for predicting the efficacy of transarterial chemoembolization in hepatocellular carcinoma

Transarterial chemoembolization (TACE) is generally used to treat patients with hepatocellular carcinoma (HCC), a common and deadly cancer; however, its efficacy varies according to factors such as tumor volume, stage, serum alpha-fetoprotein level, and chosen feeding artery. In addition, gene-related factors have been recently suggested to be involved in the regulation and prediction of TACE outcomes. Accordingly, genes could serve as effective biomarkers to select patients who can benefit from TACE. These gene-related factors can activate signaling pathways affecting cancer cell survival while regulating the epithelial-mesenchymal transition, angiogenesis, and the tumor microenvironment, all directly associated with tumor progression, thereby affecting TACE efficacy. Moreover, this disordered gene expression is associated with poor prognosis in patients with HCC, including TACE resistance, postoperative recurrence, and metastasis. To identify the exact relationship between various genes and TACE efficacy, this review summarizes the involvement of protein-coding and non-coding genes and single nucleotide polymorphisms in TACE efficacy for predicting the efficacy of TACE; the present findings may help improve the efficacy of TACE in clinical settings.

Proteomics analysis of colon cancer progression

BACKGROUND

The aim of this pilot study was to identify proteins associated with advancement of colon cancer (CC).

METHODS

A quantitative proteomics approach was used to determine the global changes in the proteome of primary colon cancer from patients with non-cancer normal colon (NC), non-adenomatous colon polyp (NAP), non-metastatic tumor (CC NM) and metastatic tumor (CC M) tissues, to identify up- and down-regulated proteins. Total protein was extracted from each biopsy, trypsin-digested, iTRAQ-labeled and the resulting peptides separated using strong cation exchange (SCX) and reverse-phase (RP) chromatography on-line to electrospray ionization mass spectrometry (ESI-MS).

RESULTS

Database searching of the MS/MS data resulted in the identification of 2777 proteins which were clustered into groups associated with disease progression. Proteins which were changed in all disease stages including benign, and hence indicative of the earliest molecular perturbations, were strongly associated with spliceosomal activity, cell cycle division, and stromal and cytoskeleton disruption reflecting increased proliferation and expansion into the surrounding healthy tissue. Those proteins changed in cancer stages but not in benign, were linked to inflammation/immune response, loss of cell adhesion, mitochondrial function and autophagy, demonstrating early evidence of cells within the nutrient-poor solid mass either undergoing cell death or adjusting for survival. Caveolin-1, which decreased and Matrix metalloproteinase-9, which increased through the three disease stages compared to normal tissue, was selected to validate the proteomics results, but significant patient-to-patient variation obfuscated interpretation so corroborated the contradictory observations made by others.

CONCLUSION

Nevertheless, the study has provided significant insights into CC stage progression for further investigation.

Proteomics analysis of colon cancer progression

Background

The aim of this pilot study was to identify proteins associated with advancement of colon cancer (CC).

Methods

A quantitative proteomics approach was used to determine the global changes in the proteome of primary colon cancer from patients with non-cancer normal colon (NC), non-adenomatous colon polyp (NAP), non-metastatic tumor (CC NM) and metastatic tumor (CC M) tissues, to identify up- and down-regulated proteins. Total protein was extracted from each biopsy, trypsin-digested, iTRAQ-labeled and the resulting peptides separated using strong cation exchange (SCX) and reverse-phase (RP) chromatography on-line to electrospray ionization mass spectrometry (ESI-MS).

Results

Database searching of the MS/MS data resulted in the identification of 2777 proteins which were clustered into groups associated with disease progression. Proteins which were changed in all disease stages including benign, and hence indicative of the earliest molecular perturbations, were strongly associated with spliceosomal activity, cell cycle division, and stromal and cytoskeleton disruption reflecting increased proliferation and expansion into the surrounding healthy tissue. Those proteins changed in cancer stages but not in benign, were linked to inflammation/immune response, loss of cell adhesion, mitochondrial function and autophagy, demonstrating early evidence of cells within the nutrient-poor solid mass either undergoing cell death or adjusting for survival. Caveolin-1, which decreased and Matrix metalloproteinase-9, which increased through the three disease stages compared to normal tissue, was selected to validate the proteomics results, but significant patient-to-patient variation obfuscated interpretation so corroborated the contradictory observations made by others.

Conclusion

Nevertheless, the study has provided significant insights into CC stage progression for further investigation.

Investigating the therapeutic potential and mechanism of curcumin in breast cancer based on RNA sequencing and bioinformatics analysis

BACKGROUND

Breast cancer is a prevalent cancer in female. This study aims to investigate the therapeutic potential and mechanism of curcumin in breast cancer.

METHODS

After cultivation, human breast cancer cells (MCF-7 cells) were treated with 0.1% (v/v) 15 µmol/ml curcumin-dimethylsulfoxide solution and 0.1% (v/v) dimethylsulfoxide, respectively, at 37 °C and 5% CO₂ for 48 h. Total RNA was extracted, cDNA library was constructed, and cDNAs were amplified and sequenced. After data preprocessing, the Cufflinks software was utilized to identify differentially expressed genes (DEGs, |log₂ fold change| > 0.5 and p value < 0.05). Then, functional and pathway enrichment analyses were performed through DAVID (p value < 0.05) and WebGestalt [false discovery rate (FDR) < 0.05], respectively. Furthermore, drug and disease association analyses (FDR < 0.05) were conducted through WebGestalt and DAVID, respectively. STRING was employed to construct protein-protein interaction (PPI) network (combined score > 0.4).

RESULTS

After DEGs screening, 347 DEGs were identified. Up-regulated DEGs were enriched in 14 functions and 3 pathways, and associated with 12 drugs. Down-regulated DEGs were enriched in 14 functions and 9 pathways, and associated with 14 drugs. Moreover, 5 DEGs were associated with breast cancer, including PGAP3, MAP3K1, SERPINE1, PON2, and GSTO2. PPI network was constructed, and the top DEGs were FOS, VIM, FGF2, MAPK1, SPARC, TOMM7, PSMB10, TCEB2, SOCS1, COL4A1, UQCR11, SERPINE1, and ISG15.

CONCLUSION

Curcumin might have therapeutic potential in breast cancer through regulating breast cancer-related genes, including SERPINE1, PGAP3, MAP3K1, MAPK1, GSTO2, VIM, SPARC, and FGF2. However, validations are required.

Distribution of Glutathione S-Transferase Omega Gene Polymorphism with Different Stages of HBV Infection Including Hepatocellular Carcinoma in the Egyptian Population

BACKGROUND

Infection with hepatitis B virus (HBV) is a major global public health problem, with a wide spectrum of clinical manifestations. Human cytosolic glutathione-S-transferases (GSTs) include several classes such as alpha (A), mu (M), pi (P), sigma (S), zeta (Z), omega (O) and theta (T). The present study aimed to investigate the role of GST omega genes (GSTO1 and GSTO2) in different groups of patients infected with HBV.

MATERIALS AND METHODS

HBV groups were classified according to clinical history, serological tests and histological analysis into normal carriers (N), acute (A), chronic (CH), cirrhosis (CI) and hepatocellular carcinoma (HCC) cases. The study focused on determination of the genotypes of GST omega genes (GSTO1 and GSTO2) and GST activity and liver function tests.

RESULTS

The results showed that GSTO1 (A/A) was decreased in N, A, CH, CI and HCC groups compared to the C-group, while, GSTO1 (C/A) and GSTO1(C/C) genotypes were increased significantly in N, A, CH, CI and HCC groups. GSTO2 (A/A) was decreased in all studied groups as compared to the C-group but GSTO2(A/G) and GSTO2(G/G) genotypes were increased significantly. In addition, GST activities, albumin and TP levels were decreased in all studied groups compared to the C-group, while the activities of transaminases were increased to differing degrees.

CONCLUSIONS

The results indicate that GSTO genetic polymorphisms may be considered as biomarkers for determining and predicting the progression of HBV infection.

Association of GSTO2 (N142D), GSTT1, and GSTM1 Polymorphisms With Graft-Versus-Host Disease in Allogeneic Hematopoietic Stem Cell Transplant Recipients

OBJECTIVES

Graft-versus-host disease is a major problem after bone marrow transplant. GSTM1, GSTT1, and GSTO2 are important genes that interfere with xenobiotic and drug metabolism. Polymorphisms of these genes may influence the metabolism of immunosuppressive drugs given for inhibition of graft-versus-host disease and may influence their susceptibility to diseases, which bone marrow transplant could alleviate.

MATERIALS AND METHODS

We examined the polymorphisms of 2 groups: The first group was composed of 88 patients who had undergone a bone marrow transplant and 100 otherwise healthy persons; the second group was composed of 54 patients without graft-versus-host disease and 34 patients with graft-versus-host disease. We used polymerase chain reaction-restriction fragment length polymorphism method for genotyping GSTO2 and also for multiplexing polymerase chain reactions for GSTT1 and GSTM1 genotypes.

RESULTS

No significant association existed between the genotypes GSTO2 (DD: P = .458, OR 0.422), GSTM1 (P = .349, OR 1.52), or GSTT1 (P = .887, OR 1.086), and the incidence of GVHD. Moreover, we saw no association between these polymorphisms and the problems that lead to bone marrow transplant (GSTO2: DD, P = .181, OR 0.465; GSTM1: P = .699, OR 0.892; GSTT1: P = .656, OR 0.845). We showed that men have more bone marrow transplants than do women (P = .019, OR 2.034).

CONCLUSIONS

Our results show that these poly-morphisms may have no effect on the metabolism of drugs used to treat graft-versus-host disease and also, may play no significant role in creating the problems that lead to bone marrow transplant.

Polymorphisms of glutathione S-transferase genes and survival of resected hepatocellular carcinoma patients

AIM: To investigate the effects of single nucleotide polymorphisms (SNPs) in glutathione S-transferase (GST) genes on survival of hepatocellular carcinoma (HCC) patients.

METHODS: Twelve tagging SNPs in GST genes (including GSTA1, GSTA4, GSTM2, GSTM3, GSTO1, GSTO2 and GSTP1) were genotyped using Sequenom MassARRAY iPLEX genotyping method in a cohort of 214 Chinese patients with resected HCC. The Cox proportional hazards model and log-rank test were performed to determine the SNPs related to outcome. Additionally, stratified analysis was performed at each level of the demographic and clinical variables. An SNP-gene expression association model was further established to investigate the correlation between SNP and gene expression.

RESULTS: Two SNPs (GSTO2: rs7085725 and GSTP1: rs4147581) were significantly associated with overall survival in HCC patients (P = 0.035 and 0.042, respectively). In stratified analysis, they were more significantly associated with overall survival in patients with younger age, male gender and cirrhosis. We further investigated cumulative effects of these two SNPs on overall survival in HCC patients. Compared with the patients carrying no unfavorable genotypes, those carrying 2 unfavorable genotypes had a 1.70-fold increased risk of death (P < 0.001). The cumulative effects were more significant in those patients with younger age, male gender and cirrhosis (HR = 2.00, 1.94 and 1.97, respectively; all P < 0.001). Additionally, we found that heavy smoking resulted in a significantly worse overall survival in those patients carrying variant alleles of rs7085725 (HR = 2.07, 95%CI: 1.13-3.76, P = 0.018). The distributions of GSTO2: rs7085725 and GSTP1: rs4147581 genotypes were associated with altered gene expression and contributed to influences on overall survival.

CONCLUSION: Our study provides the first evidence that GSTO2 and GSTP1 gene polymorphisms may serve as independent prognostic markers for HCC patients.

GSTO1*C/GSTO2*G haplotype is associated with risk of transitional cell carcinoma of urinary bladder

PURPOSE

To clarify the role of genetic polymorphisms of GSTO1 (rs4925) and GSTO2 (rs156697) in individual susceptibility to urinary bladder cancer.

METHODS

Case-control study consisting of 187 patients with histologically confirmed transitional cell carcinoma (TCC) of urinary bladder and 140 age- and gender-matched cancer-free controls was carried out. Genotyping of GSTO1 and GSTO2 was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We found that carriers of mutant GSTO2*G/G genotype were at increased risk of the development of TCC (OR 2.6, 95% CI 1.2-5.8, p = 0.041), while GSTO1 rs4925 polymorphism was not significantly associated with TCC risk (p = 0.450). According to smoking status, smokers with GSTO2*G/G genotype had significantly higher risk of TCC of urinary bladder (OR 4.3, 95% CI 1.6-11.2, p = 0.003) compared to wild-type carriers with no smoking history. We further analyzed the effects of GSTO1/GSTO2 haplotypes on TCC risk, based on the linkage disequilibrium found for GSTO1 (rs4925) and GSTO2 (rs156697) (D' = 0.309, p = 0.001). The study subjects with GSTO1*C/GSTO2*G (GSTO1 wild-type/GSTO2 mutant) haplotype were at the highest risk of the development of transitional cell carcinoma of urinary bladder (OR 2.8, 95% CI 1.5-5.2, p = 0.002).

CONCLUSIONS

Our results indicate that GSTO1*C/GSTO2*G haplotype is associated with increased risk of TCC. The modifying effect of GSTO2*G/G genotype on individual susceptibility to TCC is more pronounced, when associated with smoking.

Genetic polymorphisms in Glutathione S-transferase Omega (GSTO) and cancer risk: a meta-analysis of 20 studies

Glutathione S-transferase Omega (GSTO) plays an important role in the development of cancer. Recently, a number of studies have investigated the association between single nucleotide polymorphisms on GSTO and susceptibility to cancer; however, the results remain inconclusive. We performed a meta-analysis of 20 studies, involving 4770 cases and 5701 controls to identify the strength of association by pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Overall, the pooled results revealed a significantly increased risk of susceptibility for GSTO2 polymorphism (GG vs. AA: OR = 1.20, 95%CI: 1.02-1.41, Pheterogeneity = 0.116), but no significant association was found for GSTO1 polymorphism. Subgroup analysis showed that GSTO2 polymorphism significantly increased cancer risk in Caucasian population (GG vs. AA: OR = 1.32, 95%CI 1.06-1.64, Pheterogeneity = 0.616) and GSTO2 polymorphism was significantly associated with elevated risk of breast cancer (GG vs. AA OR = 1.37, 95%CI: 1.06-1.77; Pheterogeneity = 0.281). This meta-analysis demonstrates that GSTO2 polymorphism may significantly increase cancer risk in Caucasian population and is associated with elevated risk of breast cancer; while GSTO1 polymorphism is not associated with cancer risk.

Relationship between GSTT1 gene polymorphism and hepatocellular carcinoma in patients from China

OBJECTIVE

The results from studies on associations of the glutathione S-transferase T1 (GSTT1) gene polymorphism and hepatocellular carcinoma (HCC) risk in Chinese populations are still conflicting. This meta- analysis was performed to evaluate the relationship in detail.

METHODS

Eligible reports were recruited into this meta-analysis from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database). Results were expressed with odds ratios (OR) for dichotomous data, and 95% confidence intervals (CI) were also calculated.

RESULTS

Eighteen investigations were identified for the analysis of association between polymorphic deletion of GSTT1 and HCC, consisting of 2,693 patients with HCC and 4,696 controls. Null genotype of GSTT1 was associated with HCC susceptibility in Chinese (OR=1.53, 95%CI: 1.28-1.82; P<0.00001).

CONCLUSION

The GSTT1 null genotype is associated with HCC susceptibility in Chinese.

Influence of GSTO2 (N142D) genetic polymorphism on acute renal rejection

Acute renal allograft rejection remains an important problem following kidney transplantation. Several immunological and non-immunological factors intervene in renal graft rejection. Glutathione S-transferase super family is one of the important enzymes for biotransformation of both exogenous and endogenous xenobiotic compounds such as immunosuppressive drugs. The new class of this family is omega that includes two subunits GSTO1 and GSTO2. In this study 282 samples were collected from renal recipients of Namazi hospital in Shiraz-Iran during 2007-2010 years. Also 300 healthy samples as control group were collected from Shiraz population, included in our study. The primary outcome of this study was defined as biopsy-proven acute rejection during 1 year of renal transplantation. We applied polymerase chain reaction-restriction fragment length polymorphism method for determination of GSTO2 N142D polymorphism. Our result showed no significant association between GSTO2 polymorphism and acute rejection. Also this genetic variant has no significant effect with the risk of end stage renal disease. Cadaveric donor type for acute rejection significantly differed between acute rejection and non acute rejection patients (P=0.004). The combination effect of donor type and GSTO2 polymorphism indicates DD genotype with cadaver donor type increase risk of acute rejection (OR=3.82, 95% CI 1.80-12.37, P=0.02).

Association of glutathione S-transferase omega gene polymorphisms with progression of head and neck cancer

This study investigated the influence of glutathione S-transferase omega 1 (GSTO1) and GSTO2 gene polymorphisms on susceptibility and aggressiveness of head and neck squamous cell carcinoma (HNSCC). A case-control study consisting of 300 HNSCC cases and 299 age and sex- matched normal control was performed. Genotyping of GSTO1*A140D and GSTO2*N142D polymorphisms was determined using the polymerase chain reaction-restriction fragment length polymorphism method. Our results revealed that the frequencies of GSTO1 and GSTO2 genotypes were not significantly different between HNSCC cases and controls. No significant differences were found in smoking or drinking status between cases and controls. However, HNSCC individuals with the GSTO1*D140 varient were significantly associated with nodal metastasis (OR = 0.53, 95 %CI = 0.31-0.91, P = 0.020) and advanced pathological stage (OR = 0.33,95 %CI = 0.15-0.70, P = 0.032), while no significant association was observed between GSTO2 genotype and clinicopathological features. Therefore, our findings suggest that the GSTO1*D140 variant genotype in individuals might play a protective role against the aggressiveness of HNSCC.

A meta-analysis of the relationship between glutathione S-transferases gene polymorphism and hepatocellular carcinoma in Asian population

The results from the published studies on the association between glutathione S-transferases (GST) gene polymorphism and hepatocellular carcinoma (HCC) in Asian population are still conflicting. GSTM1, GSTT1 and GSTP1 are the mainly mutant sites reported at present. This meta-analysis was performed to evaluate the relationship between GST gene polymorphism and HCC risk in Asians. Association studies were identified from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) on February 1, 2012, and eligible investigations were synthesized using meta-analysis method. Results were expressed with odds ratios (OR) for dichotomous data, and 95 % confidence intervals (CI) were also calculated. Twenty-five investigations were identified for the analysis of association between polymorphic deletion of GSTM1 and HCC, consisting of 3,547 patients with HCC and 6,132 controls. There was a marked association between GSTM1 null genotype and HCC susceptibility (OR 1.48, 95 % CI 1.19-1.85, P = 0.0004). GSTM1 null genotype was associated with HCC risk in Chinese. Furthermore, null genotype of GSTT1 was associated with HCC susceptibility in Asians. For the GSTM1-GSTT1 interaction analysis, the dual null genotype of GSTM1/GSTT1 was significantly associated with HCC susceptibility in Asian population. However, GSTP1 ile105 val gene polymorphism was not associated with HCC risk in Asian population. In conclusion, GSTM1/GSTT1 null genotype is associated with the HCC susceptibility. However, GSTP1 gene polymorphism is not associated with HCC risk.