Influence of polymorphisms in genes encoding immunoregulatory proteins and metabolizing enzymes on susceptibility and outcome in patients with diffuse large B-cell lymphoma treated with rituximab

Pharmacogenetics in diffuse large B-cell lymphoma treated with R-CHOP: Still an unmet challenge

DLBCL is the most common lymphoma representing approximately one third of all non-Hodgkin lymphomas and about 40% of patients do not benefit of the standard first-line immune-chemotherapeutic treatment (i.e., R-CHOP - rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) that is administered as upfront therapy to substantially all patients independently from the stage of disease and other prognostic parameters. The administration of other pharmacological treatments is in fact limited to selected patients, unfitting for R-CHOP. Although clinical prognostic scores, i.e. International Prognostic Index (IPI), and molecular classifiers based on the cell of origin are available, at present no biomarkers predictive of R-CHOP response has been identified and validated. Constitutional polymorphisms of genes involved in the mechanism of action of drugs included in R-CHOP have been suggested by many authors to play a role in the efficacy and in some case in the toxicity of this treatment. Thus, it is conceivable that in the future, after proper validation, some polymorphisms can be used as pharmacogenetic biomarkers of therapeutic outcome in this disease setting. This review discusses the status of the art on molecular biomarkers predictive of DLBCL prognosis and deals with the relevant issue of the variability in response to DLBCL drug treatment. Overall, this review focuses on single nucleotide polymorphisms (SNPs) that, based on a candidate gene approach or on a GWAS analysis, have been suggested to play a role in response to R-CHOP. In particular, SNPs discovered by a candidate gene approach are related to gene involved in drug transport (i.e. ATP-binding cassette transporters), drug metabolism, drug detoxification enzymes, oxidative stress, apoptosis, DNA repair, immunity and angiogenesis. Data from a GWAS analysis performed in DLBCL patients treated with R-CHOP, identified two SNPs associated with clinical outcomes related to genes involved in pivotal cellular processes and in transcriptional regulation and cell cycle progression, respectively. Ongoing prospective pharmacogenetic clinical trials, including a GWAS study we performed, have also been discussed.

LTA, LEP, and TNF-a Gene Polymorphisms are Associated with Susceptibility and Overall Survival of Diffuse Large B-Cell lymphoma in an Arab Population: A Case-Control Study

Objective:

In this study, we aimed to explore the relationship between five selected proinflammatory and immune-mediated genes (TNF rs1800629G>A, rs361525G>A, rs1799964T>C, LTA rs1800683G>A, rs909253A>G, TNFAIP8 rs1042541C>T, LEPR rs1327118G>C, and LEP rs2167270G>A) and the risk and overall survival of DLBCL patients within the Jordanian Arab population.

Methods:

One hundred twenty-five patients (125) diagnosed with DLBCL at the King Abdullah University Hospital (KAUH) between 2013 and 2018 and 238 healthy cancer-free control subjects with similar geographic and ethnic backgrounds to the patients were included in the study. Genomic DNA was extracted from the formalin-fixed paraffin-embedded tissues of the subjects and from peripheral blood samples of the controls. The Sequenom MassARRAY^® sequencer system (iPLEX GOLD) was used. The analyses included assessments of population variability and survival.

Results:

Our study showed significant differences in the distribution of the studied polymorphisms of DLBCL between the patients and controls for TNF rs1800629G>A, LTA rs909253 G>A and LEP rs2167270 G>A. TNF rs1800629G>A (p = 0.01), in which the G allele harbors a higher risk of DLBCL (GG and GA genotypes when compared with AA genotype) (p = 0.044). The LTA rs909253 A>G polymorphism is associated with a higher risk of DLBCL in the allelic model (p = .004). LEP rs2167270 G>A polymorphism is associated with a decreased risk of DLBCL in the recessive mode models (p = .03). Subjects with the dominant model for TNF-a rs1799964 (TT genotype in comparison with the combined TT/TC genotype) and patients with the homozygous genotype (GG) of rs361525 have better overall survival rates.

Conclusion:

Our results confirmed the diversity and the heterogeneity of the disease. Although the study has a limitation because of its relatively small size, it clearly emphasizes the significance of ancestry and genetic composition as the determinants of DLBCL risk and behavior.

The effect of LTA gene polymorphisms on cancer risk: an updated systematic review and meta- analysis

Purpose: To provide a comprehensive account of the association of five Lymphotoxin-α (LTA) gene polymorphisms (rs1041981, rs2229094, rs2239704, rs746868, rs909253) with susceptibility to cancer.

Methods: A literature search for eligible candidate gene studies published before 28 February 2020 was conducted in the PubMed, Medline, Google Scholar and Web of Science. The following combinations of main keywords were used: (LTA OR Lymphotoxin alpha OR TNF-β OR tumor necrosis factor-beta) AND (polymorphism OR mutation OR variation OR SNP OR genotype) AND (cancer OR tumor OR neoplasm OR malignancy OR carcinoma OR adenocarcinoma). Potential sources of heterogeneity were sought out via subgroup and sensitivity analysis, and publication bias were estimated.

Results: Overall, a total of 24 articles with 24577 cases and 33351 controls for five polymorphisms of LTA gene were enrolled. We identified that rs2239704 was associated with a reduced risk of cancer. While for other polymorphisms, the results showed no significant association with cancer risk. In the stratified analysis of rs1041981, we found that Asians might have less susceptibility to cancer. At the same time, we found that rs2239704 was negatively correlated with non-Hodgkin lymphoma (NHL). While, for rs909253, an increased risk of cancer for Caucasians and HCC susceptibility were uncovered in the stratified analysis of by ethnicity and cancer type.

Conclusion:LTA rs2239704 polymorphism is inversely associated with the risk of cancer. LTA rs1041981 polymorphism is negatively associated with cancer risk in Asia. While, LTA rs909253 polymorphism is a risk factor for HCC in Caucasian population.

Polymorphism in IKZF1 gene affects clinical outcome in diffuse large B-cell lymphoma

IKZF1 encodes a transcription factor involved in B-cell maturation and differentiation. We genotyped 218 diffuse large B-cell lymphoma (DLBCL) patients and 715 unrelated controls using a TaqMan allelic discrimination assay. No statistical difference was observed in the genotype distribution of the IKZF1 rs4132601 polymorphism between DLBCL patients and controls. However, the 2-year PFS rate of patients with the IKZF1 TT genotype was 54.3% compared to 68.6% in those with the IKZF1 G+ genotypes. Moreover, the IKZF1 rs4132601 polymorphism retained its independent prognostic impact on PFS. A more pronounced effect of the IKZF1 TT genotype on PFS was detected in patients with low/intermediate low IPI-risk group. When analysis was restricted to patients with GCB-type pattern, those with the IKZF1 TT genotype achieved a lower 5-year OS rate than the patients with the IKZF1 G+ genotypes (19.6 vs. 56%). This study provides the first evidence for the association of IKZF1 variants with DLBCL outcome.

Association of Interleukin-10 -3575T>A and -1082A>G polymorphisms with non-Hodgkin lymphoma susceptibility: a comprehensive review and meta-analysis

A number of studies have investigated the associations between IL-10 polymorphisms and non-Hodgkin lymphoma (NHL) susceptibility; however, the conclusions were still contradictory. To acquire a more precise estimation of the association, we performed the current meta-analysis. We systematically searched publications from EMBASE and MEDLINE, and calculated pooled odds ratios (ORs) and 95 % confidence intervals (CIs) using either fixed-effects or random-effects model. Genotype-based IL-10 mRNA expression analysis was performed using online public database of 270 individuals with three different ethnicities. A total of 10,703 cases and 11,823 controls from 10 studies were included for the -3575T>A polymorphism, 10,226 cases and 12,215 controls from 17 studies for the -1082A>G polymorphism. Pooled results indicated that IL-10 -3575T>A was associated with increased risk of diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), especially for Caucasians and hospital-based population. There was no association between IL-10 -1082A>G and NHL risk. However, subgroup analysis showed that IL-10 -1082GG might confer increased susceptibility to FL. In summary, this meta-analysis indicated that -3575T>A polymorphism was associated with altered NHL susceptibility for Caucasians and hospital-based population, especially for DLBCL and FL subtypes. The -1082A>G polymorphism may contribute to increased FL risk. Further large-scale population studies among different ethnicities are needed to validate these results.

The role of gender in patients with diffuse large B cell lymphoma treated with rituximab-containing regimens: a meta-analysis

INTRODUCTION

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL). Although gender has not been included in prognostic systems, male gender has been found as a bad prognostic indicator in Hodgkin lymphoma, follicular lymphoma and chronic lymphocytic leukemia. The relationship between gender and prognosis is not clear in patients with DLBCL treated with rituximab-containing regimens. The aim of this meta-analysis is to determine the prognostic/predictive role of gender in patients with DLBCL treated with rituximab-containing regimens.

MATERIAL AND METHODS

We systematically searched for studies investigating the relationships between gender and prognosis in DLBCL treated with rituximab-containing regimens. After careful review, survival data were extracted from eligible studies. A meta-analysis was performed to generate combined hazard ratios for overall survival, disease-free survival (DFS) and event-free survival (EFS).

RESULTS

A total of 5635 patients from 20 studies were included in the analysis. Our results showed that male gender was associated with poor prognosis in terms of overall survival (OS) (hazard ratio (HR) = 1.155; 95% confidence interval (CI): 1.037-1.286; p < 0.009). The pooled hazard ratio for DFS and EFS showed that male gender was not statistically significant (HR = 1.219; 95% CI: 0.782-1.899; p = 0.382, HR = 0.809; 95% CI: 0.577-1.133; p = 0.217).

CONCLUSIONS

The present meta-analysis indicated male gender to be associated with a poor prognosis in patients with DLBCL treated with rituximab-containing regimens.

Inherited variation in immune response genes in follicular lymphoma and diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) both depend on immune-mediated survival and proliferation signals from the tumor microenvironment. Inherited genetic variation influences this complex interaction. A total of 89 studies investigating immune-response genes in DLBCL and FL were critically reviewed. Relatively consistent association exists for variation in the tumor necrosis factor alpha (TNFA) and interleukin-10 loci and DLBCL risk; for DLBCL outcome association with the TNFA locus exists. Variations at chromosome 6p31-32 were associated with FL risk. Importantly, individual risk alleles have been shown to interact with each other. We suggest that the pathogenetic impact of polymorphic genes should include gene-gene interaction analysis and should be validated in preclinical model systems of normal B lymphopoiesis and B-cell malignancies. In the future, large cohort studies of interactions and genome-wide association studies are needed to extend the present findings and explore new risk alleles to be studied in preclinical models.

The association between the polymorphisms of TNF-α and non-Hodgkin lymphoma: a meta-analysis

Many genetic variations in the promoter region of tumor necrosis factor alpha (TNF-α) may confer host susceptibility to cancer by influencing TNF-α expression. Nevertheless, the results remain inconclusive. The current meta-analysis was performed to investigate the association between three common TNF-α promoter polymorphisms and the risk of non-Hodgkin lymphoma (NHL). A literature search was conducted mainly from PubMed for all eligible studies. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to assess the association of TNF-α polymorphisms with the risk of NHL. TNF-α -308 A allele showed a statistically significant increased risk for NHL under the homozygous (AA vs. GG, OR = 1.51, 95 % CI = 1.26-1.80) and recessive (OR = 1.47, 95 % CI = 1.23-1.75) models, respectively. The stratified analyses showed an increased risk of NHL with the presence of TNF-α -308 A allele among Africans and Caucasians, but a decreased risk among Asians. No association was observed between -238 G/A polymorphism and NHL risk either in the overall analysis or in the stratified analysis. Similarly, pooled analysis did not reveal an altered risk of NHL with -857 C/T polymorphism. Nonetheless, a statistically significant association was observed among Asians when stratified by ethnicity. Among the three genetic variations of interest, TNF-α -308 G/A polymorphism was significantly associated with the risk of NHL; neither -238 G/A nor -857 C/T polymorphism was shown to alter the overall NHL risk; however, stratified analysis by ethnicity observed a statistically significant association between -857 C/T polymorphism and the risk of NHL among Asians.

GSTT1 deletion is related to polycyclic aromatic hydrocarbons-induced DNA damage and lymphoma progression

The interrelationship between genetic susceptibility and carcinogenic exposure is important in cancer development. Polymorphisms in detoxification enzymes of the glutathione-S-transferases (GST) family are associated with an increased incidence of lymphoma. Here we investigated the molecular connection of the genetic polymorphism of GSTT1 to the response of lymphocytes to polycyclic aromatic hydrocarbons (PAH). In neoplastic situation, GSTT1 deletions were more frequently observed in lymphoma patients (54.9%) than in normal controls (42.0%, P = 0.009), resulting in an increased risk for lymphoma in individuals with GSTT1-null genotype (Odds ratio = 1.698, 95% confidence interval = 1.145-2.518). GSTT1 gene and protein expression were accordingly decreased in GSTT1-deleting patients, consistent with activated profile of cell cycle regulation genes. Mimicking environmental exposure using long-term repeat culture with low-dose PAH metabolite Hydroquinone, malignant B- and T-lymphocytes presented increased DNA damage, pCHK1/MYC expression and cell proliferation, which were counteracted by ectopic expression of GSTT1. Moreover, GSTT1 expression retarded xenograft tumor formation of Hydroquinone-treated lymphoma cells in nude mice. In non-neoplastic situation, when zebrafish was exposed to PAH Benzo(a)pyrene, molecular silencing of gstt1 enhanced the proliferation of normal lymphocytes and upregulated myca expression. Collectively, these findings suggested that GSTT1 deletion is related to genetic predisposition to lymphoma, particularly interacting with environmental pollutants containing PAH.

Positive association between lymphotoxin-alpha variation rs909253 and cancer risk: a meta-analysis based on 36 case-control studies

Lymphotoxin-alpha (LTA) polymorphism rs909253 has been reported to be a risk factor for cancers, but some results are inconsistent. To establish a more conclusive association, we performed a meta-analysis of this variant with cancers. A systematic search was performed for informative case-control studies of rs909253 with cancers among literature databases, including PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Chinese Periodical Database. After a comprehensive filtration procedure, 36 publications involved with 35,677 participants were selected for the current meta-analysis. Stratified factors, such as cancer type, populations, and source of control, were used for a better interpretation of this variant. Minimal heterogeneity was shown in the current meta-analysis (I (2) = 0.0%, P = 0.48). Our results show a significant association of rs909253 and cancer risk (odds ratio (OR) = 1.12, P (z) < 0.001). In the subgroup analysis, significant association of rs909253 was found in adenocarcinoma (OR = 1.16, P (z) < 0.001) and hematological malignancy (OR = 1.10, P (z) < 0.001). Our meta-analyses established a significant association of rs909253 with cancer risk among multiple populations including North Americans, Asians, and Europeans.