Genetic polymorphisms and multiple myeloma risk: a meta-analysis

Causal relationships between inflammatory factors and multiple myeloma: A bidirectional Mendelian randomization study

Changes in serum inflammatory factors occur throughout the onset and multiple myeloma (MM) progression, the feedback loops make it harder to distinguish between causes and effects. In the present study, we performed a bidirectional summary-level Mendelian randomization (MR) analysis to elucidate the causal relationships of C-reactive protein (CRP) and inflammatory regulators with MM. Summary-level data of genetic variants associated with inflammation were extracted from two genome-wide association studies (GWASs) on CRP and human cytokines, while data on MM was from large meta-analyses of GWASs among 372 617 UK Biobank participants. The inverse-variance weighted (IVW) method was used as the primary MR analysis and MR-Egger, weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were used as the sensitivity analyses. Our results suggested that higher levels of monocyte-specific chemokine-3 (IVW estimate odds ratio [OR_IVW ] per SD genetic cytokines change: 1.24; 95% confidence interval [CI]: 1.03-1.49; P = .02), vascular endothelial growth factor (1.14, 1.03-1.27; P = .02), interleukin-10 (1.33, 1.01-1.75; P = .04) and interleukin-7 (1.24, 1.03-1.48; P = .02) were associated with increased risk of MM, while lower levels of tumor necrosis factor-β (0.84, 0.74-0.92; P < .001) was strongly associated with an increased risk of MM. And conversely, genetically predicted MM was related to increased levels of interleukin-17 (IVW estimate β: 0.051, 95% CI: 0.018-0.085; P = 2.7 × 10^-3 ). Besides, we observed no such significant associations for other inflammatory factors in our study. Overall, our study provides genetic evidence on the relationships of CRP and systemic inflammatory regulators with MM. Targeted interventions of specific inflammatory factors may have implications to alleviate MM cancer risk.

Association Of -308G/A, -238G/A TNF-α Polymorphisms with Multiple Myeloma Risk and Survival: A Systematic Review and Meta-Analysis

INTRODUCTION

Tumor necrosis factor alpha (TNF-α) is a cytokine with a key role in proinflammation and multiple diseases, including cancer. The gene encoding TNF-α is located within a highly polymorphic region on chromosome 6p21.3; two polymorphisms -308G/A (rs1800629) and -238G/A (rs361525) have been associated with occurrence of human diseases. There is a debate in recent meta-analyses that reached discrepant conclusions regarding the potential role of TNF-α polymorphisms in multiple myeloma (MM) risk. The aim of this systematic review and meta-analysis is to investigate the association between the aforementioned two polymorphisms with the risk and survival of MM.

MATERIALS AND METHODS

Eligible articles were identified through an extensive search in PubMed database (end of search: June 18, 2020). The pooled effect estimates were calculated following the random-effects models by Der Simonian and Laird. Separate analyses were conducted by ethnicity. Between-study heterogeneity was quantified, and the deviation of genotype frequencies in controls from the Hardy-Weinberg equilibrium was evaluated.

RESULTS

Eighteen studies (2934 cases, 4291 controls) have been included in the quantitative synthesis examining risk and 5 studies for survival (557 cases). No association was found between -308G/A and -238G/A TNF-α polymorphisms and MM susceptibility in all genetic models for both Caucasian and East Asian populations. There was no association between -308G/A and -238G/A TNF-α polymorphisms and survival (overall or progression-free) of MM.

CONCLUSION

This systematic review and meta-analysis did not reveal a significant effect of -308G/A and -238G/A TNF-α polymorphisms upon risk or survival of MM.

ABCB1, ABCG2, ABCC1, ABCC2, and ABCC3 drug transporter polymorphisms and their impact on drug bioavailability: what is our current understanding?

INTRODUCTION

Interindividual differences in drug response are a frequent clinical challenge partly due to variation in pharmacokinetics. ATP-binding cassette (ABC) transporters are crucial determinants of drug disposition. They are subject of gene regulation and drug-interaction; however, it is still under debate to which extend genetic variants in these transporters contribute to interindividual variability of a wide range of drugs.

AREAS COVERED

This review discusses the current literature on the impact of genetic variants in ABCB1, ABCG2 as well as ABCC1, ABCC2, and ABCC3 on pharmacokinetics and drug response. The aim was to evaluate if results from recent studies would increase the evidence for potential clinically relevant pharmacogenetic effects.

EXPERT OPINION

Although enormous efforts have been made to investigate effects of ABC transporter genotypes on drug pharmacokinetics and response, the majority of studies showed only weak if any associations. Despite few unique results, studies mostly failed to confirm earlier findings or still remained inconsistent. The impact of genetic variants on drug bioavailability is only minor and other factors regulating the transporter expression and function seem to be more critical. In our opinion, the findings on the so far investigated genetic variants in ABC efflux transporters are not suitable as predictive biomarkers.