Prognostic value and susceptibility of BAX rs4645878 polymorphism in cancer: A systematic review and meta-analysis

Positive correlation between Bax and Bcl-2 gene polymorphisms with the risk of endometriosis: A case-control study

Background

Endometriosis is a chronic, gynecological disorder, and the disease's pathogenesis is still debatable. Genes related to apoptosis have been revealed to be deregulated in endometriosis.

Objective

This study investigates the relationship between polymorphic variants of Bax -248G > A and Bcl-2 -938C > A promoter regions with endometriosis risk in an Iranian population.

Materials and Methods

In this case-control study, the polymorphisms of Bax -248G > A and Bcl-2 -938C > A promoter regions were analyzed in 127 Iranian cases and 125 controls who were referred to Ali-ibn-Abi Taleb Educational hospital, Zahedan, Iran between May 2022 and February 2023. The genotypic analysis was performed for all the subjects using the polymerase chain reaction-restriction fragment length polymorphism method.

Results

The frequencies of mutant allele A carriers and the A allele of Bax -248G > A polymorphism showed about 2-fold significant increase of endometriosis risk (p = 0.04; p = 0.01, respectively). The frequencies of the mutant genotype AA and A allele carriers of Bcl-2 -938C > A polymorphism were approximately 4 and 2.5-fold higher in endometriosis compared to the control women, which were highly significant (p > 0.001). Moreover, the allele A frequency of Bcl-2 -938C > A was associated with a 2-fold higher risk of endometriosis (p > 0.001). Furthermore, the combination effects of these 2 single nucleotide polymorphisms showed that women with Bax -248G > A GGand Bcl-2 -938C > A AA variant alleles were associated with about 5 times higher risk of endometriosis (p > 0.001). Notably, a significant difference was observed in mutant allele distribution between minimal/mild (stage I and II) and moderate/severe (stage III and IV) women with endometriosis disease.

Conclusion

The results of our study provide evidence that Bcl-2 -938C > A and Bax -248G > A single nucleotide polymorphisms might be associated with the risk of endometriosis.

Expression of pyroptosis-associated genes and construction of prognostic model for thyroid cancer

Background

Thyroid cancer (THCA) is a common endocrine malignancy. This study aimed to explore the expression of pyroptosis-related genes in THCA and establish a prognosis prediction model.

Methods

Differentially expressed pyroptosis-related genes (DEPRGs) were identified in The Cancer Genome Atlas (TCGA) and the Molecular Signatures Database (MSigDB). Subsequently, these genes were subjected to Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. A least absolute shrinkage and selection operator (LASSO) regression model was employed to establish a DEPRG signature, and its reliability was validated through survival analysis and receiver operating characteristic (ROC) curves. Patients in TCGA-THCA cohort were stratified into two risk groups. The biological functions of the genes between the two risk groups were assessed through gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA). Finally, expression of DEPRGs was validated using datasets from the Gene Expression Omnibus (GEO) and the Human Protein Atlas (HPA) databases.

Results

Six DEPRGs were identified in TCGA dataset. Through LASSO Cox regression analysis, we determined IL6, TP63, NOD1, and BAX to be significant. Kaplan-Meier survival analysis demonstrated that patients with THCA expressing high levels of NOD1 and classified as low-risk individuals exhibited prolonged survival. The multifactorial ROC curves yielded area under the curve (AUC) scores exceeding 0.7 for risk score, age, and T-stage, affirming their significance as independent prognostic factors as determined by multivariate analysis. Additionally, we observed elevated expression levels of BAX and NOD1 in THCA using data derived from the HPA database and the GEO dataset.

Conclusions

We established a novel DEPRG signature for predicting the prognosis of THCA, potentially offering a promising therapeutic marker for THCA treatment.

Analysis of the Polymorphisms and Expression Levels of the BCL2, BAX and c-MYC Genes in Patients with Ovarian Cancer

Ovarian cancer (OC) is one of the biggest problems in gynecological oncology and is one of the most lethal cancers in women worldwide. Most patients with OC are diagnosed at an advanced stage; therefore, there is an urgent need to find new biomarkers for this disease. Gene expression profiling is proving to be a very effective tool for exploring new molecular markers for OC patients, although the relationship between such markers and patient survival and clinical outcomes is still elusive. Moreover, polymorphisms in genes encoding both apoptosis-associated proteins and oncoproteins may serve as key markers of cancer susceptibility. The aim of our study was to analyze the polymorphisms and expressions of the BCL2, BAX and c-MYC genes in a group of 198 women, including 98 with OC. The polymorphisms and mRNA expressions of the BCL2, BAX and c-MYC genes were analyzed using real-time PCR. The analysis of the BAX (rs4645878; G>A) and c-MYC (rs4645943; C>T) polymorphisms showed no association with ovarian cancer risk. The BCL2 polymorphism (rs2279115; C>A) showed a significant difference in the frequency of genotypes between the studied groups (CC: 23.47% vs. 16.00%, AA: 25.51% vs. 37.00%; p = 0.046; OR = 1.61). Furthermore, the expression levels of the BCL2 and c-MYC genes showed a decrease at the transcript level for OC patients compared to the control group (BCL2: 17.46% ± 3.26 vs. 100% ± 8.32; p < 0.05; c-MYC: 37.56% ± 8.16 vs. 100% ± 9.12; p < 0.05). No significant changes in the mRNA level were observed for the BAX gene (104.36% ± 9.26 vs. 100% ± 9.44; p > 0.05). A similar relationship was demonstrated in the case of the protein expressions of the studied genes. These findings suggest that the CC genotype and C allele of the BCL2 polymorphism could be genetic risk factors for OC development. A gene expression analysis indicated that BCL2 and c-MYC are associated with OC risk.

Molecular Evaluation of the Impact of Polymorphic Variants in Apoptotic (Bcl-2/Bax) and Proinflammatory Cytokine (TNF-α/IL-8) Genes on the Susceptibility and Progression of Myeloproliferative Neoplasms: A Case-Control Biomarker Study

The regulation of apoptosis (the programmed cell death) is dependent on the crucial involvement of BCL2 and BAX. The Bax-248G>A and Bcl-2-938 C>A polymorphic variations in the promoter sequences of the Bax and Bcl-2 gene have been recently associated with low Bax expression, progression to advanced stages, treatment resistance, and shortened overall survival rate in some hematological malignancies, including chronic myeloid leukemia (CML) and other myeloproliferative neoplasms. Chronic inflammation has been linked to various stages of carcinogenesis wherein pro-inflammatory cytokines play diverse roles in influencing cancer microenvironment leading to cell invasion and cancer progression. Cytokines such as TNF-α and IL-8 have been implicated in cancer growth in both solid and hematological malignancies with studies showing their elevated levels in patients. Genomic approaches have in recent years provided significant knowledge with the regard to the association of certain SNPs (single nucleotide polymerphisms) either in a gene or its promoter that can influence its expression, with the risk and susceptibility to human diseases including cancer. This study has investigated the consequences of promoter SNPs in apoptosis genes Bax-248G>A (rs4645878)/Bcl-2-938C>A (rs2279115) and pro-inflammatory cytokines TNF-α rs1800629 G>A/IL-8 rs4073 T>A on the risk and susceptibility towards hematological cancers. The study design has 235 individuals both male and female enrolled as subjects that had 113 cases of MPDs (myeloproliferative disorders) and 122 healthy individuals as controls. The genotyping studies were conducted through ARMS PCR (amplification-refractory mutation system PCR). The Bcl-2-938 C>A polymorphism showed up in 22% of patients in the study, while it was observed in only 10% of normal controls. This difference in genotype and allele frequency between the two groups was significant (p = 0.025). Similarly, the Bax-248G>A polymorphism was detected in 6.48% of the patients and 4.54% of the normal controls, with a significant difference in genotype and allele frequency between the groups (p = 0.048). The results suggest that the Bcl-2-938 C>A variant is linked to an elevated risk of MPDs in the codominant, dominant, and recessive inheritance models. Moreover, the study indicated allele A as risk allele which can significantly increase the risk of MPDs unlike the C allele. In case of Bax gene covariants, these were associated with an increased risk of MPDs in the codominant inheritance model and dominant inheritance model. It was found that the allele A significantly enhanced the risk of MPDs unlike the G allele. The frequencies of IL-8 rs4073 T>A in patients was found to be TT (16.39%), AT (36.88%) and AA (46.72%), compared to controls who were more likely to have frequencies of TT (39.34%), AT (37.70%) and AA (22.95%) as such, respectively. There was a notable overrepresentation of the AA genotype and GG homozygotes among patients compared to controls in TNF-α polymorphic variants, with 6.55% of patients having the AA genotype and 84% of patients being GG homozygotes, compared to 1.63% and 69%, respectively in controls. The data from the current study provide partial but important evidence that polymorphisms in apoptotic genes Bcl-2-938C>A and Bax-248G>A and pro-inflammatory cytokines IL-8 rs4073 T>A and TNF-α G>A may help predict the clinical outcomes of patients and determine the significance of such polymorphic variations in the risk of myeloproliferative diseases and their role as prognostic markers in disease management using a case-control study approach.

BAX -248 G>A and BCL2 -938 C>A Variant Lowers the Survival in Patients with Nasopharyngeal Carcinoma and Could be Associated with Tissue-Specific Malignancies: A Multi-Method Approach

BACKGROUND

The association of BAX -248 G>A and BCL2 -938 C>A with different cancers created conflicts.  We studied the correlation and the effect of these polymorphisms in patients with Nasopharyngeal Carcinoma (NPC).  Methods: PCR-RFLP and Sanger sequencing were used to detect polymorphisms. Statistical analysis including forest plot and Kaplan-Meier Log-rank test was conducted to investigate the association and effect of these SNPs on the NPC patients' survival. The computational study was performed to investigate the possible regulatory role between these polymorphisms and the poor survival of NPC patients. Meta-analysis was executed to check the tissue-specific association of these polymorphisms in the context of global cancer prognosis.

RESULTS

We observed an increased and significant association of BAX -248 G>A [GA:OR=5.29, 95%CI=1.67,16.67, P=0.004; GA+AA:OR=5.71, 95%CI=1.82,17.90, P =0.002; A:OR=5.33, 95%CI=1.76,16.13, P=0.003], and BCL2 -938 C>A [CA:OR=2.26, 95%CI=1.03,4.96, P=0.04; AA:OR=3.56, 95%CI=0.97,13.05, P=0.05; CA+AA:OR=3.10, 95%CI=1.51,6.35, P=0.002; A:OR=2.90, 95% CI=1.59,5.29, P=0.0005] with the risk of NPC. Also, these SNPs were strongly correlated with poor survival in NPC patients (lower estimated survival mean, lower estimated proportion surviving at 5 years with p <0.05). The computational study showed that these SNPs altered the binding affinity of transcription factors HIF1, SP1, PAX3, PAX9 and CREB towards promoter (Lower p indicates strong affinity). The meta-analysis revealed the tissue-specific association of these polymorphisms. BAX -248 G>A showed a significant correlation with carcinomas [A vs G:OR=1.60, 95%CI=1.09,2.34, P=0.01; AA vs GG:OR=2.61, 95%CI=1.68,4.06, p <0.001; AA+GA vs GG:OR=1.53,95%CI=1.04,2.25, P=0.02); AA vs GG+GA:OR=2.53, 95%CI=1.65,3.87, p <0.001], and BCL2 -938 C>A with other malignancies [A vs C:OR=1.45, 95%CI=1.26,1.66, p <0.001; AA vs CC:OR=2.07, 95%CI: 1.15,3.72, P=0.01; AA+CA vs CC:OR=1.42, 95%CI=1.18,1.72, p <0.001; AA vs CC+CA:OR=1.89, 95%CI=1.02,3.50, P=0.04].

CONCLUSIONS

BAX -248 G>A and BCL2 -938 C>A was associated with poor survival in NPC patients. It may increase cancer susceptibility through transcriptional regulation. Moreover, these SNPs' effects could be tissue-specific.
.

Genetic and epigenetic analysis of the BAX and BCL2 in the placenta of pregnant women complicated by preeclampsia

The current study examined the effects of BAX and BCL2 polymorphisms and methylation as well as mRNA expression on susceptibility to PE. After delivery, the placentas were collected from 92 women with PE, as well as 106 normotensive pregnant women. The BAX rs4645878 and BCL2 rs2279115 polymorphisms were genotyped by the PCR-RFLP method. Methylation-specific PCR (MSP) was used for analysis of promoter methylation. mRNA expression was assayed by Quantitative RT-PCR. In addition, in silico analysis was performed by bioinformatics tools. There was no relationship between PE and placental BAX rs4645878 and BCL2 rs2279115 polymorphisms. The groups were not significantly different regarding the promoter methylation of BAX gene. Nonetheless, the MM status of BCL2 promoter had a significantly higher frequency in the PE group and was associated with 2.7-fold higher risk of PE (OR = 2.7, 95% CI = 1.3-5.6; P = 0.01). The relative mRNA expression of BCL2 was decreased in the placentas of PE women (P < 0.0001). The expression of BAX gene was not significantly different between the two groups. There was no association between placental BAX rs4645878 and BCL2 rs2279115 polymorphisms and mRNA expression levels. In silico analysis indicated that BAX rs4645878 and BCL2 rs2279115 polymorphisms were located in the core recognition site of different transcription factors and these substitutions of wild allele resulted in the loss and/ or change of these binding sites and subsequently may alter BCL2 and BAX expression. This study showed that the BAX and BCL2 polymorphisms and BAX promoter methylation were not associated with PE risk. The BCL2 promoter methylation was associated with lower BCL2 expression and higher PE susceptibility.

The role of FAS, FAS-L, BAX, and BCL-2 gene polymorphisms in determining susceptibility to unexplained recurrent pregnancy loss

PURPOSE

Idiopathic recurrent pregnancy loss (RPL) is a multifactorial reproductive disorder where an impaired control of apoptosis is likely involved. Triggering the cell death mechanism occurs in a spatiotemporal manner and is strongly related to a healthy pregnancy. Single nucleotide polymorphisms (SNPs) at the regulatory regions of genes are known to influence the expression patterns of apoptosis-related molecules.

METHODS

A total of 296 unrelated female Brazilian patients were evaluated for clinical-demographic variables and genetic factors: 140 women who had experienced an unexplained RPL (with at least two consecutive abortions) and 156 healthy multiparous women. In all patients, six SNPs were evaluated in genes of apoptosis-related pathways: FAS (rs2234767, rs1800682), FAS-L (rs763110, rs5030772), BAX (rs4645878), and BCL-2 (rs2279115) by PCR followed by a restriction fragment length polymorphism (RFLP)-based analysis.

RESULTS

The BAX-248GA genotype is independently associated with idiopathic RPL [adjusted OR = 0.30, 95% CI 0.13-0.70, P = 0.005] susceptibility. In the same multivariate model, the variables ethnicity, smoking, and alcohol consumption were statistically associated with RPL susceptibility (P < 0.05). No association with RPL susceptibility was reported for the remaining SNPs.

CONCLUSION

Our study is the first to evaluate the role of the main SNPs from both the extrinsic and intrinsic apoptosis pathways in RPL susceptibility. The association of BAX-248G/A with RPL susceptibility suggests that maternal predisposition for RPL has an essential contribution from genes involved in the delicate balance of endometrium cell turnover (cell death/proliferation). Therefore, apoptotic genes may represent promising targets for future studies on healthy pregnancies and the spectrum of pregnancy disorders.