Adverse prognostic impact of vascular endothelial growth factor gene polymorphisms in patients with diffuse large B-cell lymphoma

Association of single nucleotide variants in VEGFA and KDR with the risk and angiogenic features of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype and dependent on angiogenesis (AG), whose main effectors are VEGFA and VEGFR2. Functional single nucleotide variants (SNVs) are described in VEGFA and KDR genes. However, it still unknown whether VEGFA - 2578C/A, -2489C/T, -1154G/A, -634G/C, -460C/T and KDR-604T/C, -271G/A, +1192G/A and +1719A/T SNVs act on DLBCL risk and angiogenic features. Genomic DNA from 168 DLBCL patients and 205 controls was used for SNV genotyping. Angiogenesis was immunohistochemically assessed in tumor biopsies, with reactions for VEGFA, VEGFR2, and CD34. VEGFA -1154GG genotype were associated with 1.6-fold higher DLBCL risk. KDR + 1192GG plus KDR + 1719 TT and KDR + 1192GG plus VEGFA - 2578CC combined genotypes are associated with 2.19- and 2.04-fold higher risks of DLBCL, respectively. VEGFA - 634GG or GC genotypes are associated with increased microvessel density and VEGFA levels. No relationship was observed between SNVs and cell-of-origin classification of DLBCL, but higher VEGFA and VEGFR2 were seen in non-germinal center tumors.

Angiogenesis' related genetic variants alter clinical features and prognosis of diffuse large B-cell lymphoma patients

OBJECTIVES

Single nucleotide variants (SNVs) in vascular endothelial growth factor A (VEGFA) and VEGFA receptor (KDR) genes confer different inherited abilities in angiogenesis (AG) pathway. We aimed in the present study to evaluate influence of six VEGFA and four KDR SNVs in clinical features and survival of diffuse large B-cell lymphoma (DLBCL) patients.

METHODS

One hundred and sixty-eight DLBCL patients diagnosed between June 2009-September 2014 were enrolled in the study. Patients were homogeneously treated with R-CHOP. Genotypes were identified in genomic DNA by real-time polymerase chain reaction.

RESULTS

Patients with VEGFA -634CC and +936CT or TT genotypes were at increased risk of showing grade III / IV toxicities and not achieving complete remission with treatment, and shorter event-free and overall survival were seen in patients with VEGFA -1154GA or AA genotype and VEGFA ATAGCC haplotype.

CONCLUSION

Our data suggest that inherited abnormalities in AG's gene modulate clinical features and prognosis of DLBCL patients homogeneously treated with R-CHOP.

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.

New Insights into Diffuse Large B-Cell Lymphoma Pathobiology

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL), accounting for about 40% of all cases of NHL. Analysis of the tumor microenvironment is an important aspect of the assessment of the progression of DLBCL. In this review article, we analyzed the role of different cellular components of the tumor microenvironment, including mast cells, macrophages, and lymphocytes, in the tumor progression of DLBCL. We examined several approaches to confront the available pieces of evidence, whereby three key points emerged. DLBCL is a disease of malignant B cells spreading and accumulating both at nodal and at extranodal sites. In patients with both nodal and extranodal lesions, the subsequent induction of a cancer-friendly environment appears pivotal. The DLBCL cell interaction with mature stromal cells and vessels confers tumor protection and inhibition of immune response while delivering nutrients and oxygen supply. Single cells may also reside and survive in protected niches in the nodal and extranodal sites as a source for residual disease and relapse. This review aims to molecularly and functionally recapitulate the DLBCL–milieu crosstalk, to relate niche and pathological angiogenic constitution and interaction factors to DLBCL progression.

VEGF121, is predictor for survival in activated B-cell-like diffuse large B-cell lymphoma and is related to an immune response gene signature conserved in cancers

Tumor microenvironment including endothelial and immune cells plays a crucial role in tumor progression and has been shown to dramatically influence cancer survival. In this study, we investigated the clinical relevance of the gene expression of key mediators of angiogenesis, VEGF isoforms 121, 165, and 189, and their receptors (VEGFR-1 and R-2) in a cohort of patients (n = 37) with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) from the Collaborative Trial in Relapsed Aggressive Lymphoma (CORAL). In patients with ABC-like DLBCL, but not in patients with GCB-like DLBCL, low VEGF₁₂₁ expression was associated with a significantly better survival than in those with high VEGF₁₂₁ level: 4-year overall survival at 100% vs 36% (p = .011), respectively. A specific gene signature including 57 genes was correlated to VEGF₁₂₁ expression level and was analyzed using a discovery process in 1,842 GSE datasets of public microarray studies. This gene signature was significantly expressed in other cancer datasets and was associated with immune response. In conclusion, low VEGF₁₂₁ expression level was significantly associated with a good prognosis in relapsed/refractory ABC-like DLBCL, and with a well-conserved gene-expression profiling signature related to immune response. These findings pave the way for rationalization of drugs targeting immune response in refractory/relapsed ABC-like DLBCL.