Association of MDR1 single-nucleotide polymorphisms and haplotype variants with multiple myeloma in Chinese Jiangsu Han population

Current perspectives on interethnic variability in multiple myeloma: Single cell technology, population pharmacogenetics and molecular signal transduction

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This review discusses the emerging single cell technologies and applications in Multiple myeloma (MM), population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction.

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The role(s) of epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of MM are also discussed.

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It is understood that ethnic component acts as a driver of variable response to chemotherapy in different sub-populations globally.

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This review augments our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, myeloma microenvironment at the molecular and cellular level, and developing precision medicine strategies to combat this malignancy.

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The emerging single cell technologies hold great promise for enhancing our understanding of MM tumor heterogeneity and clonal diversity.

Multiple myeloma (MM) is an aggressive cancer characterised by malignancy of the plasma cells and a rising global incidence. The gold standard for optimum response is aggressive chemotherapy followed by autologous stem cell transplantation (ASCT). However, majority of the patients are above 60 years and this presents the clinician with complications such as ineligibility for ASCT, frailty, drug-induced toxicity and differential/partial response to treatment. The latter is partly driven by heterogenous genotypes of the disease in different subpopulations. In this review, we discuss emerging single cell technologies and applications in MM, population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction, as well as the role(s) played by epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of the disease. Taken together, our discussions further our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, augment our understanding of the myeloma microenvironment at the molecular and cellular level and provide a basis for developing precision medicine strategies to combat this malignancy.

MDR1 gene polymorphism correlated with pathological characteristics and prognosis in patients with primary hepatocellular carcinoma receiving interventional therapy

The aim of this study was to explore the relationship of multidrug resistance gene 1 (MDR1) C1236T and C3435T single nucleotides polymorphisms (SNPs) with hepatocellular carcinoma (HCC) pathological features and prognosis. A total of 143 patients with HCC were treated with transcatheter arterial chemoembolization. Moreover, 251 controls were included in the study. C1236T and C3435T single nucleotide polymorphisms (SNPs) were detected by PCR-RFLP. Association of C1236T and C3435T SNPs with HCC was analyzed subsequently. There was no significant difference in genotypes distribution between HCC group and control group (P>0.05), indicating comparability. Among patients with portal vein tumor thrombus, the CC+CT genotype of C1236T locus was significantly higher than that of TT genotype (P=0.031). The median progression-free survival after interventional therapy for patients with C3435T genotype T (TC+TT) and C genotype (CC) was 36 and 18 months, respectively. CC and TC+TT genotype patients with C1236T loci showed statistically significant differences in tumor size stratification (χ=4.006, P=0.045). When tumor diameter was less than 5 cm, 5-10 cm, and more than 10 cm, the mean survival time of C and T genotypes was decreased gradually. The logistic regression model suggested that lesion size, blood volume value, and permeability surface value were influential factors for response to chemoradiotherapy (all P<0.05). Univariate analysis showed that postoperative chemotherapy, portal vein tumor thrombus, and capsular invasion were correlated with overall survival in patients with HCC. Cox proportional hazard model showed that postoperative chemotherapy, capsule invasion, and portal vein tumor thrombus were independent factors of overall survival after interventional therapy in patients with HCC (all P<0.05). C1236T genotype may predict changes in pathological features of patients with HCC to a certain extent, and C3435T SNP can be used as one of the prognostic factors of HCC. Postoperative chemotherapy and portal vein tumor thrombus are independent factors of overall survival in patients with HCC.

Genetic polymorphisms and multiple myeloma risk: a meta-analysis

Previous researches exploring associations between multiple myeloma (MM) and genetic polymorphisms showed controversial results. In this investigation, we aimed to make a meta-analysis to assess the association between MM risk and genetic polymorphisms. We searched for articles on genetic polymorphism and MM risk in Web of Science and PubMed databases from 1951 to August 2019. We computed the odds ratio (OR) and 95% confidence intervals (CI) extracted from included articles. The meta-analysis showed no significant associations between MM risks and tumor necrosis factor (TNF)-α (rs1800629/rs361525/rs1799724), interleukin (IL)-6 (rs1800795), multidrug resistance 1 (MDR1) (rs1045642), Methylenetetrahydrofolate reductase (MTHFR) (rs1801131/rs1801133) polymorphisms. In summary, the study shows that the TNF-α (rs1800629/rs361525/rs1799724), IL-6 (rs1800795), MDR1 (rs1045642), and MTHFR (rs1801131/rs1801133) polymorphisms may not be associated with MM susceptibility. Thus, we do not need more expensive and useless studies to explore the associations between MM risks and these genetic polymorphisms.

Multidrug resistance 1 (MDR1/ABCB1) gene polymorphism (rs1045642 C > T) and susceptibility to multiple myeloma: a systematic review and meta-analysis

INTRODUCTION

Several studies have evaluated the association between the multidrug resistance 1 (MDR1) polymorphism (rs1045642 C > T) and multiple myeloma (MM). However, the results were not consistent. Therefore, to reach a comprehensive and reliable answer we determined the association of the MDR1 (rs1045642 C > T) polymorphism and MM in the context of meta-analysis.

METHODS

All eligible studies published in EMBASE, PubMed, and Web of Science databases before July 2017 were reviewed. Subsequently, to assess the strength of association in the dominant model, recessive model, allelic model, homozygotes contrast, and heterozygotes contrast, pooled odds ratios and 95% confidence intervals (CIs) were calculated by the fixed effects model.

RESULTS

A total of four case-control studies with 395 MM cases and 418 healthy controls were included in the meta-analysis. The overall results showed no significant association between the MDR1 (rs1045642 C > T) polymorphism and the risk of MM in genetic models (dominant model: OR = 1.04, 95% CI = 0.78-1.38; recessive model: OR = 0.74, 95% CI = 0.52-1.06; allelic model: OR = 0.90, 95% CI = 0.73-1.11; TT vs. CC: OR = 0.80, 95% CI = 0.51-1.25; and CT vs. CC: OR = 1.12, 95% CI = 0.77-1.62). No evidence of publication bias was detected except for the analysis of the recessive model.

CONCLUSION

This meta-analysis suggests that the MDR1 C > T polymorphism was not associated with the risk of MM. To confirm these findings, further comprehensive and well-designed studies are needed.

MDR1 polymorphisms affect the outcome of Chinese multiple myeloma patients

OBJECTIVE

To illustrate the association of MDR1 (Multidrug Resistance 1) polymorphisms at loci 1236, 2677, 3435 and the prognosis of multiple myeloma (MM) in Jiangsu population.

METHODS

A total of 129 MM patients were recruited from Jiangsu Province, China. The DNA was extracted from white blood cells (WBC) of peripheral blood and was amplified by polymerase chain reaction-allele specific primers (PCR-ASP). MDR1 polymorphisms at 3 loci were analyzed by electrophoresis followed by photograph or DNA direct sequencing. The association between the MDR1 and clinical outcomes were calculated by Graphpad and SPSS.

RESULTS

MDR1 alleles at locus C1236T with T had significant lower calcium level in MM patients compared with C. The genotype CT had a significantly prolonged progress free survival (PFS) compared genotype CC at locus C1236T (median time: 48 months vs. 28 months, respectively; p=0.0062; HR=0.21; 95%CI0.061-0.715) while patients carrying T allele (CT and TT) at locus C3435T had a longer PFS than patients without T allele (CC) (median time: 60 months vs. 29 months, respectively; p=0.038; HR=0.508; 95%CI 0.264-0.978). And a borderline significance was found in haplotype at loci 2677-3435 and PFS. No significant findings were revealed between OS and MDR1 polymorphisms.

CONCLUSION

MDR1 polymorphisms could affect the prognosis of multiple myeloma whereas more samples and a longer follow-up are also needed.

Haplotype Analysis of MDR1 and Risk for Cervical Cancer in Northeastern Thailand

Objective: The aim of this study was to investigate the association between genotype and haplotype of MDR1 (C1236T, G2677T/A and C3435T) and the risk for cervical cancer in Northeastern Thai women. Methods: An age-matched case-control study involving squamous cell cervical cancer (SCCA) patients (n=204) and healthy controls (n=204) was enrolled for MDR1 genotyping by real-time PCR method. Results: The genotype distribution of MDR1 in both patients and controls was not significantly different (p>0.05). The haplotype analysis showed that T-T-T was the most common haplotype in this population. Significantly increased risk of cervical cancer was observed in carriers of T-T-C and C-G-T haplotypes with ORs of 1.86 (95%CI=1.02-3.39, p=0.0416) and 2.00 (95%CI=1.18-3.40, p=0.0140), respectively. Analysis of 2677-3435 haplotype showed increased risk for cervical cancer in G-T (OR=1.55; 95% CI=1.12-2.13, p=0.0432) and T-C (OR=1.91; 95%CI=1.05-3.47, p=0.0325). Conclusion: The results provide evidence that haplotype of MDR1 may be an important risk factor for cervical cancer development in Northeastern Thai women.

The risk of clopidogrel resistance is associated with ABCB1 polymorphisms but not promoter methylation in a Chinese Han population

The goal of our study was to investigate the contribution of ABCB1 expression to the risk of clopidogrel resistance (CR). Platelets functions were measured using the Verify-Now P2Y12 assay. Applying Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP), the single-nucleotide polymorphisms (SNPs) was tested. Using bisulphite pyrosequencing assay, we investigated the association of the ABCB1 DNA methylation levels and CR. It was shown that female, hypertension, and lower albumin levels increased the risk of CR (P<0.05). If patients did not have hypoproteinaemia or had hypertension, the SNP in rs1045642 was associated with CR (CC vs. TT: albumin ≥35, P = 0.042; hypertension, P = 0.045; C vs. T: albumin ≥35, P = 0.033; hypertension, P = 0.040). Additionally, the platelet inhibition of the CT+TT genotype in rs1128503 was larger than that of the CC genotype (P = 0.021). Multivariate logistic regression analysis showed that male, higher albumin and hsCRP decreased the risk of CR, and the stent size maybe positively correlated with CR. The SNP in rs1045642 was related to all-cause mortality (P = 0.024). We did not find any relationship between the methylation levels of the ABCB1 promoter and CR. In conclusions, our study indicated that ABCB1 polymorphisms might be useful in further evaluating the pathogenesis of CR.