Genetic variation in BCL2 3'-UTR was associated with lung cancer risk and prognosis in male Chinese population

Clinical implications of the family history in patients with lung cancer: a systematic review of the literature and a new cross-sectional/prospective study design (FAHIC: lung)

Compared to other malignancies, few studies have investigated the role of family history of cancer (FHC) in patients with lung cancer, yielding largely heterogeneous results. We performed a systematic literature review in accordance with PRISMA guidelines, searching the PubMed and Scopus databases from their inception to November 25, 2023, to identify studies reporting on the role of FHC in patients with lung cancer. A total of 53 articles were included, most with a retrospective design and encompassing a variety of geographical areas and ethnicities.Thirty studies (56.6%) assessed patients with non-small cell lung cancer (NSCLC), while 17 studies (32.1%) assessed patients with mixed histologies. Overall, the rates of FHC ranged from 8.3 to 68.9%, and the rates of family history of lung cancer ranged from 2 to 46.8%. Twenty-seven studies investigated FHC as a potential risk factor for lung cancer, with more than half reporting an increased risk for subjects with FHC. Five studies reported on the potential role of FHC in determining clinical outcomes, and twelve studies examined the relationship between FHC and germline mutations. Notably, only one study reported a significantly increased rate of germline mutations, including ATM, BRCA2, and TP53, for patients with a family history of lung cancer compared to those without, but both groups had a low prevalence of mutations (< 1%).The FAHIC-Lung (NCT06196424) is the first cross-sectional/prospective study specifically developed to identify FHC patterns and within-family clusters of other risk factors, including smoking, to guide patients with NSCLC to systematic genetic counseling. Acknowledging the largely heterogeneous results of our systematic review and considering the clinical implications of detecting pathogenic germline variants (PGVs), the FAHIC-lung study aims to identify patients potentially enriched with PGVs/likely PGVs to direct them to germline screening outside of the research setting.

Polymorphisms of the BCL2 gene associated with susceptibility to tuberculosis

Although tuberculosis (TB) is a serious public health concern, we still don’t understand why only 10% of people infected will develop the disease. Apoptosis plays a role in the interaction of Mycobacterium tuberculosis (Mtb) with the human host and it may be modified by subtle alterations in the B-cell lymphoma 2 (BCL2) gene, an anti-apoptotic regulatory element. Therefore, we investigated whether there is an association between BCL2 polymorphisms and susceptibility to TB by analyzing 130 TB cases, 108 subjects with latent TB infection (LTBI), and 163 healthy controls (HC). Logistic regression was used to calculate odds ratios (ORs) and 95% confidential intervals (95% CIs) for possible associations between single nucleotide polymorphisms (SNPs) in BCL2 and the risk of tuberculosis. We found that the G allele of rs80030866 (OR=0.62, 95%CI:0.42-0.91, P=0.015), and also the G allele of rs9955190 (OR=0.58, 95%CI:0.38-0.88, P=0.011) were less frequent in the TB group compared with the LTBI group. In addition, individuals with rs2551402 CC genotype were more likely to have LTBI than those with AA genotype (OR=2.166, 95%CI:1.046-4.484, P=0.037). Our study suggests that BCL2 gene polymorphisms may be correlated with susceptibility to both TB and LTBI.

Genetic evaluation of the variants using MassARRAY in non-small cell lung cancer among North Indians

Lung cancer is genetically diverse and a major health burden. Non-small cell lung cancer (NSCLC) accounts for 80% of total lung cancer cases and 20% cases are Small cell lung cancer (SCLC). The present case–control association study focused on the cost effective high throughput genotyping using Agena MassARRAY matrix-assisted laser desorption/ionization-time of flight, mass spectrometry (MALDI-TOF) platform to analyze the genetic association of candidate genetic variants. We performed multiplex PCR and genotyped twelve single nucleotide polymorphisms (SNPs) in 723 samples (162 NSCLC cases and 592 healthy controls). These genetic variants were selected from literature for their association with various cancers worldwide and this is the first study from the region to examine these critically important genetic variants. With prospective case–control association study design, twelve variants from ten genes were evaluated. Amongst these six variants, TCF21 (rs12190287), ERCC1 (rs2298881, 11615), ERCC5 (rs751402), ARNTL (rs4757151), BRIP1 (rs4986764) showed significant association with NSCLC risk (p ≤ 0.003) in Jammu and Kashmir population. In-silico findings of these genetic variants showed remarkable functional roles that needs in-vitro validations. It is further anticipated that such case control studies will help us in understanding the missing heritability of non-small cell lung cancer.

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.
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Identification and Validation of Two Lung Adenocarcinoma-Development Characteristic Gene Sets for Diagnosing Lung Adenocarcinoma and Predicting Prognosis

Background: Lung adenocarcinoma (LUAD) is one of the main types of lung cancer. Because of its low early diagnosis rate, poor late prognosis, and high mortality, it is of great significance to find biomarkers for diagnosis and prognosis. Methods: Five hundred and twelve LUADs from The Cancer Genome Atlas were used for differential expression analysis and short time-series expression miner (STEM) analysis to identify the LUAD-development characteristic genes. Survival analysis was used to identify the LUAD-unfavorable genes and LUAD-favorable genes. Gene set variation analysis (GSVA) was used to score individual samples against the two gene sets. Receiver operating characteristic (ROC) curve analysis and univariate and multivariate Cox regression analysis were used to explore the diagnostic and prognostic ability of the two GSVA score systems. Two independent data sets from Gene Expression Omnibus (GEO) were used for verifying the results. Functional enrichment analysis was used to explore the potential biological functions of LUAD-unfavorable genes. Results: With the development of LUAD, 185 differentially expressed genes (DEGs) were gradually upregulated, of which 84 genes were associated with LUAD survival and named as LUAD-unfavorable gene set. While 237 DEGs were gradually downregulated, of which 39 genes were associated with LUAD survival and named as LUAD-favorable gene set. ROC curve analysis and univariate/multivariate Cox proportional hazards analyses indicated both of LUAD-unfavorable GSVA score and LUAD-favorable GSVA score were a biomarker of LUAD. Moreover, both of these two GSVA score systems were an independent factor for LUAD prognosis. The LUAD-unfavorable genes were significantly involved in p53 signaling pathway, Oocyte meiosis, and Cell cycle. Conclusion: We identified and validated two LUAD-development characteristic gene sets that not only have diagnostic value but also prognostic value. It may provide new insight for further research on LUAD.

MassArray analysis of genomic susceptibility variants in ovarian cancer

Ovarian cancer (OC), a multifaceted and genetically heterogeneous malignancy is one of the most common cancers among women. The aim of the study is to unravel the genetic factors associated with OC and the extent of genetic heterogeneity in the populations of Jammu and Kashmir (J&K).Using the high throughput Agena MassARRAY platform, present case control study was designed which comprises 200 histopathological confirmed OC patients and 400 age and ethnicity matched healthy controls to ascertain the association of previously reported eleven single nucleotide polymorphisms (SNPs) spread over ten genes (DNMT3A, PIK3CA, FGFR2, GSTP1, ERCC5, AKT1, CASC16, CYP19A1, BCL2 and ERCC1) within the OC population of Jammu and Kashmir, India. The association of each variant was estimated using logistic regression analyses. Out of the 11 SNPs the odds ratio observed for three SNPs; rs2699887 was (1.72 at 95% CI: 1.19-2.48, p = 0.004), rs1695 was (1.87 at 95% CI: 1.28-2.71, p = 0.001), and rs2298881 was (0.66 at 95% CI: 0.46-0.96, p = 0.03) were found significantly associated with the OC after correction with confounding factors i.e. age & BMI. Furthermore, the estimation of interactive analyses was performed and odds ratio observed was 2.44 (1.72-3.47), p value < 0. 001 suggests that there was a strong existence of interplay between the selected genetic variants in OC, which demonstrate that interactive analysis highlights the role of gene-gene interaction that provides an insight among multiple little effects of various polymorphisms in OC.

Functional microRNA binding site variants

Germline single nucleotide polymorphisms are one of the most common genetic variations. Polymorphisms that cause nonsynonymous mutations in gene coding regions are known to cause serious deleterious downstream effects. However, even polymorphisms in noncoding regions can have profound functional consequences by disrupting essential regulatory sites. Specifically, polymorphisms that alter microRNA binding sites can disrupt the regulation of hallmark biological pathways implicated in tumorigenesis and tumor progression. Many of these microRNA-associated polymorphisms (miR-SNPs) have recently been shown to be important biomarkers of cancer risk, prognosis, and treatment outcomes. This review will summarize the functional impact of key miR-SNPs and define a subset of miR-SNPs that may be clinically useful prognostic or predictive biomarkers.

Twenty-gene-based prognostic model predicts lung adenocarcinoma survival

Introduction

Lung adenocarcinoma (LAC) accounts for more than a half of non-small cell lung cancer with high morbidity and mortality. Progression of treatment has not accelerated the improvement of its prognosis. Hence, it is an urgent need to develop novel biomarkers for its early diagnosis and treatment.

Materials and methods

In this study, we proposed to identify LAC survival-related genes through comprehensive analysis of large-scale gene expression profiles. LAC gene expression data sets were obtained from The Cancer Genome Atlas (TCGA). Identification of differentially expressed genes (DEGs) in LAC compared with adjacent normal lung tissues was first performed followed by univariate Cox regression analysis to obtain genes that are significantly associated with LAC survival (SurGenes). Then, we conducted sure independence screening (SIS) for SurGenes to identify more reliable genes and the prognostic signature for LAC survival prediction. Another two lung cancer data sets from TCGA and Gene Expression Omnibus (GEO) were used for the validation of prognostic signature.

Results

A total of 20 genes were obtained, which were significantly associated with the overall survival (OS) of LAC patients. The prognostic signature, a weighted linear combination of the 20 genes, could successfully separate LAC samples with high OS from those with low OS and had robust predictive performance for survival (training set: p-value <2.2×10⁻¹⁶; testing set: p-value =2.04×10⁻⁵, area under the curve (AUC) =0.615). Combined with GEO data set, we obtained four genes, that is, FUT4, SLC25A42, IGFBP1, and KLHDC8B that are found in both the prognostic signature and DEGs of LAC in GEO data set.

Discussion

The prognostic signature combined with multi-gene expression profiles provides a moderate OS prediction for LAC and should be helpful for appropriate treatment method selection.

Genetic polymorphisms of Bcl-2 promoter in cancer susceptibility and prognosis: a meta-analysis

Bcl-2 is critical for tumorigenesis. However, previous studies on the association of Bcl-2 promoter polymorphisms with predisposition to different cancer types are somewhat contradictory. Therefore, we performed this meta-analysis regarding the relationship between Bcl-2 promoter single nucleotide polymorphisms (SNPs) and cancer susceptibility and prognosis. Up to August 2016, 32 original publications were identified covering two Bcl-2 promoter SNPs (rs2279115 and rs1801018). Our results showed statistically significant association between rs2279115 and cancer susceptibility and prognosis in all four genetic models but not in rs1801018. Subgroups analysis indicated that rs2279115 was associated with a significantly higher risk of cancer susceptibility in Asia but not in Caucasian. Furthermore, rs2279115 was associated with a significantly higher risk in digestive system cancer and endocrine system cancer but not in breast cancer, respiratory cancer and hematopoietic cancer. Simultaneously, rs2279115 was correlated with a significantly higher risk of cancer prognosis in Asia but not in Caucasian. Considering these promising results, rs2279115 may be a tumor marker for cancertherapy in Asia. Sensitivity analysis show four gene model were stable, and no publication bias was observed in all four gene model. Large sample size, different ethnic population and different cancer type are warranted to validate this association.

MicroRNA-related polymorphisms in apoptosis pathway genes are predictive of clinical outcome in patients with limited disease small cell lung cancer

We examined the impact of single nucleotide polymorphisms (SNPs) at miRNA binding sites in the 3'-UTRs of genes in the apoptosis pathway on the prognosis of patients with limited disease-small cell lung cancer (LD-SCLC). Twelve tagSNPs in seven genes were genotyped using blood samples from 146 LD-SCLC patients treated with chemoradiotherapy. Cox proportional hazard regression models and recursive partitioning analysis were performed to identify SNPs significantly associated with overall survival. Three SNPs, CASP8: rs1045494 (C > T), PIK3R1: rs3756668 (A > G) and CASP7: rs4353229 (T > C), were associated with longer overall survival in LD-SCLC patients after chemoradiotherapy. The adjusted hazard ratios (95% confidence intervals) were 0.480 (0.258-0.894), 0.405 (0.173-0.947) and 0.446 (0.247-0.802), respectively, and remained significant after multiple comparison correction. Moreover, subset analysis showed these SNPs were still predictive of overall survival in stage III patients. Recursive partitioning analysis enabled patients to be classified into three risk subgroups based on unfavorable genotype combinations of the rs1045494 and rs4353229 SNPs. These findings suggest miRNA-related polymorphisms in the apoptosis pathway may be useful biomarkers for selection of LD-SCLC patients likely to benefit from chemoradiotherapy.

Phosphorylation of Bcl-2 plays an important role in glycochenodeoxycholate-induced survival and chemoresistance in HCC

Hepatocellular carcinoma (HCC) is a highly malignant tumor and can evolve rapidly to resistance to chemotherapies. Glycochenodeoxycholate (GCDA), which is toxic and hydrophobic, is the main ingredient in the bile and associated with carcinogenesis of gastrointenstinal tumors. Bcl-2 is the most important anti-apoptotic protein and overexpressed in various human tumors. In the present study, we found that GCDA can induce the chemoresistance of human liver cancer cells and specific depletion of Bcl-2 by RNA interference blocks GCDA-stimulated chemoresistance, which indicate the pivotal role of Bcl-2 in such process. Mechanistically, GCDA simultaneously stimulates phosphorylation of Bcl-2 at Ser70 site and activates extracellular signal-regulated kinase 1/2 (ERK1/2), and inhibition of ERK1/2 by PD98059 (MAPK/ERK1/2 inhibitor) or siRNA (targeting ERK1/2) suppresses GCDA-stimulated phosphorylation of Bcl-2 and significantly attenuates the survival and chemoresistance induced by GCDA in liver cancer cells. Thus, GCDA-induced survival and chemoresistance of liver cancer cells may occur through activation of Bcl-2 by phosphorylation at Ser70 site through MAPK/ERK1/2 pathway, which may contribute to the development of human liver cancer and chemoresistance.

The genetic variations in DNA repair genes ERCC2 and XRCC1 were associated with the overall survival of advanced non-small-cell lung cancer patients

It was reported that DNA repair can confer cancer cell resistance to therapeutic treatments by activating antiapoptotic cellular defense. We hypothesized that genetic variants of DNA repair genes may be associated with lung cancer prognosis. Seventeen tagging single‐nucleotide polymorphism (tagSNPs) selected from 12 DNA repair genes were genotyped in 280 advanced non‐small‐cell lung cancer (NSCLC) patients by TaqMan assay. The associations of these SNPs and overall survival of advanced NSCLC patients were investigated. Advanced NSCLC patients carrying ERCC2 rs50872 CT+TT genotypes had significantly longer median survival time (MST) and decreased death risk than patients with rs50872 CC genotype [log‐rank P = 0.031; adjusted HR(95% CI) = 0.73 (0.55–0.98), P = 0.033]. These effects were mainly seen among younger patients (≤65 years old) [HR(95% CI) = 0.57 (0.37–0.87), P = 0.010], patients without surgery [HR(95% CI) = 0.68 (0.47–0.98), P = 0.036] but with chemotherapy [HR(95% CI) = 0.64 (0.46–0.91), P = 0.012] or radiotherapy [HR(95% CI) = 0.58 (0.38–0.89), P = 0.013]. Meanwhile, compared to advanced NSCLC patients with rs25487 GG genotype, patients carrying XRCC1 rs25487 GA+AA genotypes had significantly shorter MST (MST = 11.7 vs. 16.7, log‐rank P = 0.048). In addition, advanced NSCLC patients carrying the ERCC2 rs50872 CC in combination with XRCC1 rs25487 GA+AA genotype had the shortest MST (11.2 month) and highest death risk [HR(95% CI) = 1.70 (1.15–2.52), P = 0.008] when compared with those carrying rs50872 CT+TT and rs25487 GG genotype (MST = 22.0 month). The ERCC2 rs50872 T allele was associated with favorable but XRCC1 rs25487 A allele with bad survival for advanced NSCLC in Chinese population, which may offer novel biomarkers for predicting clinical outcomes.

Association of the functional BCL-2 rs2279115 genetic variant and small cell lung cancer

As a well-known oncogene, B cell lymphoma-2 (BCL-2) can promote cancer cell survival through preventing their apoptosis. Several functional BCL-2 single nucleotide polymorphisms (SNPs), such as rs2279115, rs1801018, and rs1564483, have been identified and might contribute to cancer susceptibility. However, the involvement of these SNPs in small cell lung cancer (SCLC) was still unclear. As a result, we investigated associations between these three genetic variants and SCLC risk in a case-control design. Genotypes were determined in two independent case-control sets consisted of 520 SCLC patients and 1040 controls from two medical centers. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated utilizing unconditional logistic regression. We found that only BCL-2 rs2279115 genetic variant significantly contributed to decreased SCLC risk in Chinese Han populations, with the rs2279115 A allele as the protective allele. Stratified analyses of association between BCL2 rs2279115 SNP and SCLC risk indicated that the functional polymorphism was only significantly associated with decreased risk of the limited stage SCLC but not the extensive stage disease. Our results indicate that the BCL-2 rs2279115 genetic variant was associated with SCLC risk in Chinese populations and support the hypothesis that SNPs in regulatory regions of oncogenes might contribute to cancer susceptibility.

Role of Bcl-2 -938 C>A polymorphism in susceptibility and prognosis of cancer: a meta-analysis

The association between B-cell lymphoma 2 (Bcl-2) polymorphism and cancer is under debate and remains elusive. This meta-analysis was performed to evaluate the relationships of Bcl-2 -938 C>A polymorphism (rs2279115) with susceptibility and prognosis of cancer. Odds ratios (ORs) were used to measure the association between Bcl-2 polymorphisms and cancer risk. Hazard ratios (HRs) were used to measure the association between Bcl-2 polymorphisms and cancer prognosis. On the basis of 26 studies about Bcl-2 -938C>A polymorphism and cancer, we found Bcl-2 -938 C>A polymorphism was significantly associated with increased cancer risk in dominant model (OR = 1.12, 95%CI: 1.00-1.25, P = 0.04), recessive model (OR = 1.38, 95%CI: 1.11-1.71, P = 0.004), allelic model (OR = 1.15, 95%CI: 1.04-1.28, P = 0.007) and homozygote comparison(OR = 1.44, 95%CI: 1.11-1.87, P = 0.006). Furthermore, Bcl-2 -938 C>A polymorphism was significantly associated with increased cancer risk in Asians but not in Caucasians. Moreover, Bcl-2 -938 C>A polymorphism was not significantly associated with the prognosis of cancer (AA vs CA: OR = 0.99, 95%CI: 0.77-1.27, P = 0.93; AA vs CC: OR = 0.92, 95%CI: 0.65-1.30, P = 0.63; AC vs CC: OR = 0.94, 95%CI: 0.80-1.11, P = 0.48; CC vs AA+CA: OR = 1.21, 95%CI: 0.69-2.13, P = 0.50; AA vs CC+CA: OR = 0.99, 95%CI: 0.48-2.04, P = 0.97). Studies with larger samples and gene-environment interactions are needed to validate our findings.

MicroRNA binding site polymorphisms as biomarkers in cancer management and research

MicroRNAs (miRNAs) are important regulators of eukaryotic gene expression. They have been implicated in a broad range of biological processes, and miRNA-related genetic alterations probably underlie several human diseases. Single nucleotide polymorphisms of transcripts may modulate the posttranscriptional regulation of gene expression by miRNAs and explain interindividual variability in cancer risk and in chemotherapy response. On the basis of recent association studies published in the literature, the present review mainly summarizes the potential role of miRNAs as molecular biomarkers for disease susceptibility, diagnosis, prognosis, and drug-response prediction in tumors. Many clues suggest a role for polymorphisms within the 3' untranslated regions of KRAS rs61764370, SET8 rs16917496, and MDM4 rs4245739 as SNPs in miRNA binding sites highly promising in the biology of human cancer. However, more studies are needed to better characterize the composite spectrum of genetic determinants for future use of markers in risk prediction and clinical management of diseases, heading toward personalized medicine.

Detection of mutations by fill-in ligation reaction with enzyme-linked immunosorbent assay for rapid medical diagnosis

Several approaches for parallel genotyping have been developed with increasingly available information on DNA variation. However, these methods require either complex laboratory procedures or expensive instrumentation. None of these procedures is readily performed in local clinical laboratories. In this study, we developed a flexible genotyping method involving fill-in ligation reaction with enzyme-linked immunosorbent assay successfully applied to detect important single-nucleotide polymorphisms (SNPs) for EGFR c.2573T > G (L858R), EGFR c.2582T > A (L861Q), and EGFR c.2155G > T (G719C). This assay exhibited excellent specificity, with a sensitivity as low as 0.5%. Eight out of 62 clinical samples were identified as heterozygotes for the SNP site of L858R, whereas only two samples were identified as heterozygotes by direct sequencing. The developed method enabled accurate identification of SNP in a simple and cost-effective manner adapted to routine analysis.

Influence of BCL2 gene in major depression susceptibility and antidepressant treatment outcome

BACKGROUND

Our recent work indicated that low-expression of the anti-apoptotic protein B-cell/lymphoma 2 (Bcl-2) mRNA was observed among untreated major depressive disorder (MDD) patients, and the subsequent altered level of Bcl-2 was found to be close to the antidepressant treatment outcome. The primary aim of this present study was to examine whether a particular gene, encoding Bcl-2 (BCL2) confers risk to MDD, and likewise to investigate whether this gene acts as an indicator of antidepressant treatment outcome.

METHODS

We enrolled 178 treatment-resistant depression (TRD) and 612 non-treatment-resistant depression (NTRD) patients as well as 725 healthy controls. In total, three selected tagging SNPs (tagSNPs) of BCL2 (rs2279115, rs1801018 and rs1564483) were genotyped to test for possible association. Using TaqMan relative quantitative real-time polymerase chain reaction (PCR), we analyzed leukocytic expression of BCL2 mRNA in 47 healthy subjects.

RESULTS

Of the three SNPs, we observed no significant differences in genotype and allele frequencies between the MDD and control groups as well as between the TRD and NTRD groups. However, we found a significant association between the rs2279115C allele and TRD in males (corrected P=0.048) but not in females. Further real-time quantitative PCR analysis in healthy subjects revealed that the rs2279115 polymorphism significantly influenced BCL2 mRNA expression (P=0.03).

LIMITATIONS

This is a preliminary investigation with relatively small sample size and cross-sectional design.

CONCLUSIONS

These initial findings strengthen the hypothesis that BCL2 may play an important role in mediating the outcome of antidepressant treatment, a result that may further be confirmed by future genetic studies from large-scale populations that can overcome the limited sample size of this preliminary finding.