Pharmacogenetics of microRNAs and microRNAs biogenesis machinery in pediatric acute lymphoblastic leukemia

ncRNAs: an unexplored cellular defense mechanism in leprosy

Leprosy is an infectious disease primarily caused by the obligate intracellular parasite Mycobacterium leprae. Although it has been considered eradicated in many countries, leprosy continues to be a health issue in developing nations. Besides the social stigma associated with it, individuals affected by leprosy may experience nerve damage leading to physical disabilities if the disease is not properly treated or early diagnosed. Leprosy is recognized as a complex disease wherein socioenvironmental factors, immune response, and host genetics interact to contribute to its development. Recently, a new field of study called epigenetics has emerged, revealing that the immune response and other mechanisms related to infectious diseases can be influenced by noncoding RNAs. This review aims to summarize the significant advancements concerning non-coding RNAs in leprosy, discussing the key perspectives on this novel approach to comprehending the pathophysiology of the disease and identifying molecular markers. In our view, investigations on non-coding RNAs in leprosy hold promise and warrant increased attention from researches in this field.

Association of microRNA Polymorphisms with Toxicities Induced by Methotrexate in Children with Acute Lymphoblastic Leukemia

Methotrexate (MTX), a structurally related substance to folic acid, is an important chemotherapeutic agent used for decades in the treatment of pediatric acute lymphoblastic leukemia (ALL) and other types of cancer as non-Hodgkin lymphomas and osteosarcomas. Despite the successful outcomes observed, the primary drawback is the variability in the pharmacokinetics and pharmacodynamics between patients. The main adverse events related to its use are nephrotoxicity, mucositis, and myelosuppression, especially when used in high doses. The potential adverse reactions and toxicities associated with MTX are a cause for concern and may lead to dose reduction or treatment interruption. Genetic variants in MTX transport genes have been linked to toxicity. Pharmacogenetic studies conducted in the past focused on single nucleotide polymorphisms (SNPs) in the coding and 5'-regulatory regions of genes. Recent studies have demonstrated a significant role of microRNAs (miRNAs) in the transport and metabolism of drugs and in the regulation of target genes. In the last few years, the number of annotated miRNAs has continually risen, in addition to the studies of miRNA polymorphisms and MTX toxicity. Therefore, the objective of the present study is to investigate the role of miRNA variants related to MTX adverse effects.

Impact of microRNA polymorphisms on high-dose methotrexate-related hematological toxicities in pediatric acute lymphoblastic leukemia

Objectives

It is well known that transporter and enzyme genes could be regulated by microRNA (miRNA) at the post-transcriptional level, and single-nucleotide polymorphisms (SNPs) in miRNA, which are involved in the miRNA production and structure, may impact the miRNA expression level and then influence drug transport and metabolism. In this study, we aim to evaluate the association between miRNA polymorphisms and high-dose methotrexate (HD-MTX) hematological toxicities in Chinese pediatric patients with acute lymphoblastic leukemia (ALL).

Method

A total of 181 children with ALL were administered with 654 evaluable cycles of HD-MTX. Their hematological toxicities were evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events v5. The association between 15 candidate SNPs of miRNA and hematological toxicities (leukopenia, anemia, and thrombocytopenia) was analyzed using Fisher's exact test. Further multiple backward logistic regression analysis was used to explore the independent risk factors for grade 3/4 hematological toxicities.

Result

Rs2114358 G>A in pre-hsa-miR-1206 was related to HD-MTX-related grade 3/4 leukopenia after multiple logistic regression [GA + AA vs. GG: odds ratio (OR): 2.308, 95% CI: 1.219-4.372, P = 0.010], and rs56103835 T > C in pre-hsa-mir-323b was associated with HD-MTX-related grade 3/4 anemia (TT + TC vs. CC: OR: 0.360, 95% CI: 0.239-0.541, P = 0.000); none of the SNPs were significantly associated with grade 3/4 thrombocytopenia. Bioinformatics tools predicted that rs2114358 G>A and rs56103835 T>C would impact the secondary structure of pre-miR-1206 and pre-miR-323b, respectively, and then probably influence the expression level of mature miRNAs and their target genes.

Conclusion

Rs2114358 G>A and rs56103835 T>C polymorphism may potentially influence HD-MTX-related hematological toxicities, which may serve as candidate clinical biomarkers to predict grade 3/4 hematological toxicities in pediatric patients with ALL.

MiRNAs in Hematopoiesis and Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most common kind of pediatric cancer. Although the cure rates in ALL have significantly increased in developed countries, still 15–20% of patients relapse, with even higher rates in developing countries. The role of non-coding RNA genes as microRNAs (miRNAs) has gained interest from researchers in regard to improving our knowledge of the molecular mechanisms underlying ALL development, as well as identifying biomarkers with clinical relevance. Despite the wide heterogeneity reveled in miRNA studies in ALL, consistent findings give us confidence that miRNAs could be useful to discriminate between leukemia linages, immunophenotypes, molecular groups, high-risk-for-relapse groups, and poor/good responders to chemotherapy. For instance, miR-125b has been associated with prognosis and chemoresistance in ALL, miR-21 has an oncogenic role in lymphoid malignancies, and the miR-181 family can act either as a oncomiR or tumor suppressor in several hematological malignancies. However, few of these studies have explored the molecular interplay between miRNAs and their targeted genes. This review aims to state the different ways in which miRNAs could be involved in ALL and their clinical implications.

Influence of Genetic Variations in miRNA and Genes Encoding Proteins in the miRNA Synthesis Complex on Toxicity of the Treatment of Pediatric B-Cell ALL in the Brazilian Amazon

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer in the world. Single nucleotide variants (SNVs) in miRNA and genes encoding proteins of the miRNA synthesis complex (SC) may affect the processing of drugs used in the treatment of ALL, resulting in treatment-related toxicities (TRTs). We investigated the role of 25 SNVs in microRNA genes and genes encoding proteins of the miRNA SC, in 77 patients treated for ALL-B from the Brazilian Amazon. The 25 SNVs were investigated using the TaqMan^® OpenArray™ Genotyping System. SNVs rs2292832 (MIR149), rs2043556 (MIR605), and rs10505168 (MIR2053) were associated with an increased risk of developing Neurological Toxicity, while rs2505901 (MIR938) was associated with protection from this toxicity. MIR2053 (rs10505168) and MIR323B (rs56103835) were associated with protection from gastrointestinal toxicity, while DROSHA (rs639174) increased the risk of development. The rs2043556 (MIR605) variant was related to protection from infectious toxicity. SNVs rs12904 (MIR200C), rs3746444 (MIR499A), and rs10739971 (MIRLET7A1) were associated with a lower risk for severe hematologic toxicity during ALL treatment. These findings reveal the potential for the use of these genetic variants to understand the development of toxicities related to the treatment of ALL in patients from the Brazilian Amazon region.

Genetic variants found in paediatric oncology patients with severe chemotherapy-induced toxicity: A case series

Paediatric oncology patients who develop severe chemotherapy-induced toxicity that requires dose reduction, delay or termination of treatment are at risk of decreased treatment efficacy. Previous research has provided evidence that genetic variants in TPMT, NUDT15, UGT1A1 and DPYD are associated with toxicity of anticancer drugs. This led to pharmacogenetic guidelines that are integrated into clinical practice in paediatric oncology. Recently, novel genetic variants have been associated with a higher risk of developing chemotherapy-induced toxicity. In this case series, we selected 21 novel variants and genotyped these in nine patients with excessive chemotherapy-induced toxicity using whole exome sequencing or micro-array data. We observed that six out of nine patients carried at least one variant that, according to recent studies, potentially increased the risk of developing methotrexate- or vincristine-induced toxicity. As patient-derived genetic data are becoming widely accessible in paediatric oncology, these variants could potentially enter clinical practice to mitigate chemotherapy-induced toxicity.

Association between SNPs in microRNAs and microRNAs-Machinery Genes with Susceptibility of Leprosy in the Amazon Population

Leprosy is a chronic neurodermatological disease caused by the bacillus Mycobacterium leprae. Recent studies show that SNPs in genes related to miRNAs have been associated with several diseases in different populations. This study aimed to evaluate the association of twenty-five SNPs in genes encoding miRNAs related to biological processes and immune response with susceptibility to leprosy and its polar forms paucibacillary and multibacillary in the Brazilian Amazon. A total of 114 leprosy patients and 71 household contacts were included in this study. Genotyping was performed using TaqMan Open Array Genotyping. Ancestry-informative markers were used to estimate individual proportions of case and control groups. The SNP rs2505901 (pre-miR938) was associated with protection against the development of paucibacillary leprosy, while the SNPs rs639174 (DROSHA), rs636832 (AGO1), and rs4143815 (miR570) were associated with protection against the development of multibacillary leprosy. In contrast, the SNPs rs10739971 (pri-let-7a1), rs12904 (miR200C), and rs2168518 (miR4513) are associated with the development of the paucibacillary leprosy. The rs10739971 (pri-let-7a1) polymorphism was associated with the development of leprosy, while rs2910164 (miR146A) and rs10035440 (DROSHA) was significantly associated with an increased risk of developing multibacillary leprosy.

Genetic Variants of MicroRNA and DROSHA Genes in Association With the Risk of Tuberculosis in the Amazon Population

Tuberculosis (TB) is a chronic infection caused by Mycobacterium tuberculosis (Mtb) with high incidence and mortality. Studies reported that host genetic variants might be associated with the risk of tuberculosis. The aim of this study was to perform an association study between 26 single nucleotide polymorphisms (SNPs) and tuberculosis and evaluate whether these SNPs may confer risk factors to tuberculosis in the Amazon population. There were 52 males and 126 females, with total of 178 healthy controls. Genotyping was performed using TaqMan Open Array Genotyping. Ancestry-informative markers were used to estimate the ancestral proportions of the individuals in the case and control groups. The results indicated that the SNPs rs10035440 (DROSHA), rs7372209 (miR26-a1), rs1834306 (miR100), rs4919510 (miR608), and rs10739971 (pri-let-7a-1) were significantly associated with high risk and rs3746444 (miR499) and rs6505162 (miR423), with low risk of developing tuberculosis in the Amazon population. Our study concluded that seven miRNA polymorphisms were associated with tuberculosis. Our study contributes to a better understanding of TB pathogenesis and may promote the development of new diagnostic tools against M. tuberculosis infection.

Genetic variants associated with methotrexate-induced mucositis in cancer treatment: A systematic review and meta-analysis

Methotrexate (MTX), an important chemotherapeutic agent, is often accompanied with mucositis. The occurrence and severity are unpredictable and show large interindividual variability. In this study, we review and meta-analyze previously studied genetic variants in relation to MTX-induced mucositis. We conducted a systematic search in Medline and Embase. We included genetic association studies of MTX-induced mucositis in cancer patients. A meta-analysis was conducted for single nucleotide polymorphisms (SNPs) for which at least two studies found a statistically significant association. A total of 34 SNPs were associated with mucositis in at least one study of the 57 included studies. Two of the seven SNPs included in our meta-analysis were statistically significantly associated with mucositis: MTHFR c.677C > T (recessive, grade ≥3 vs grade 0-2, OR 2.53, 95 %CI [1.48-4.32], False Discovery Rate[FDR]-corrected p-value 0.011) and MTRR c.66A > G (overdominant, grade ≥1 vs grade 0, OR 2.08, 95 %CI [1.16-3.73], FDR-corrected p-value 0.042).

Influence of variants of the drosha, mir499a, and mir938 genes on susceptibility to acute lymphoblastic leukemia in an admixed population from the brazilian amazon

Acute Lymphoblastic Leukemia (ALL) is the most common type of cancer in children. Polymorphisms that alter the normal function of the microRNAs involved in the development of ALL have been widely investigated, although published data on these polymorphisms in admixed populations are scarce. We investigated the role of 10 polymorphisms in the microRNA and protein-coding genes of the microRNA synthesis complex in susceptibility to pediatric B-cell ALL. The study includes 100 pediatric ALL patients and 180 healthy individuals. The statistical analyses were run in SPSS v.25.0. In the case of the microRNA synthesizing genes, a significant pattern was found in only gene, that is, the rs3805500 polymorphism of DROSHA, in which the homozygous mutant (AA) genotype was associated with a threefold increase in the risk of developing ALL when compared to other genotypes (P=0.004, OR=2.913, CI=1.415-5.998). In the microRNA coding genes, the homozygous mutant rs3746444 genotype of the MIR499A gene was associated with a 17-fold increase in the risk of development of ALL (P<0.001, OR=17.797, CI=5.55-57.016). A protective effect against the development of ALL was also observed in the carriers of the wild homozygous rs2505901 genotype in the MIR938 gene. Our findings highlight the potential of these polymorphisms in the genes involving in the coding of microRNAs for the evaluation of the risk of contracting ALL in the population of the Brazilian Amazon region. These findings contribute to a more complete understanding of the complex etiology of ALL.

Implementation of Pharmacogenetics to Individualize Treatment Regimens for Children with Acute Lymphoblastic Leukemia

Despite major advances in the management and high cure rates of childhood acute lymphoblastic leukemia (ALL), patients still suffer from many drug-induced toxicities, sometimes necessitating dose reduction, or halting of cytotoxic drugs with a secondary risk of disease relapse. In addition, investigators have noted significant inter-individual variability in drug toxicities and disease outcomes, hence the role of pharmacogenetics (PGx) in elucidating genetic polymorphisms in candidate genes for the optimization of disease management. In this review, we present the PGx data in association with main toxicities seen in children treated for ALL in addition to efficacy, with a focus on the most plausible germline PGx variants. We then follow with a summary of the highest evidence drug-gene annotations with suggestions to move forward in implementing preemptive PGx for the individualization of treatment regimens for children with ALL.

Multiple genetic factors affecting the pharmacokinetic and pharmacodynamic processes of tacrolimus in Chinese myasthenia gravis patients

PURPOSE

Tacrolimus is a novel effective immunosuppressant for myasthenia gravis (MG) patients. However, the narrow therapeutic window, and high inter- and intrapatient variation in bioavailability largely limited its clinical application. This article intended to find the SNPs influencing clinical outcome and discover the possible mechanisms.

METHODS

Based on the tagSNPs genotyped by Improved Multiple Ligase Detection Reaction, Plink 1.07 was used to find the SNPs having close interaction to tacrolimus serum concentration, QMG score changes or even reasonable drug dose. Then we searched several databases to predict the possible miRNA binding rs15524 sequence. Based on the prediction, dual-luciferase reporter assay and miRNA transfection were used to discover the mechanism of how SNP rs15524 controls tacrolimus serum concentration through influencing CYP3A5 expression.

RESULTS

In this article, we found multiple SNPs on CYP3A4, CYP3A5, FKBP1A, NFATC2 genes were predicted closely related to tacrolimus serum concentration, therapeutic effect which reflected by QMG score changes or even reasonable drug dose. After in silico miRNA selection, possible relationship between hsa-miR-500a and rs15524 was found. With the help of dual-luciferase reporter assay, wild-type rs15524 (T allele) was found having a stronger binding affinity for hsa-miR-500a. Higher expression of CYP3A5 may also led by lower hsa-miR-500a level.

CONCLUSIONS

SNP rs15524 may control CYP3A5 expression by affecting the binding affinity between CYP3A5 3'UTR and hsa-miR-500a. Wild type (T allele) 3'UTR of CYP3A5 has stronger binding affinity to hsa-miR-500a and cause lower CYP3A5 expression and higher tacrolimus serum concentration.

The Role of MicroRNA in Paediatric Acute Lymphoblastic Leukaemia: Challenges for Diagnosis and Therapy

Acute lymphoblastic leukaemia (ALL) is the most common cancer of childhood. Although the overall survival of children with ALL is now more than 90%, leukaemia remains one of the leading causes of death from disease. In developed countries, the overall survival of patients with ALL has increased to more than 80%; however, those children cured from ALL still show a significant risk of short- and long-term complications as a consequence of their treatment. Accordingly, there is a need not only to develop new methods of diagnosis and prognosis but also to provide patients with less toxic therapies. MicroRNAs (miRNAs) are small ribonucleic acids (RNA), usually without coding potential, that regulate gene expression by directing their target messenger RNAs (mRNAs) for degradation or translational suppression. In paediatric ALL, several miRNAs have been observed to be overexpressed or underexpressed in patient cohorts compared to healthy individuals, while numerous studies have identified specific miRNAs that can be used as biomarkers to diagnose ALL, classify it into subgroups, and predict prognosis. Likewise, a variety of miRNAs identify as candidate targets for treatment, although there are numerous obstacles to overcome before their clinical use in patients. Here, we summarise the roles played by different miRNAs in childhood leukaemia, focussing primarily on their use as diagnostic tools and potential therapeutic targets, as well as a role in predicting treatment outcome. Finally, we discuss the potential roles of miRNA in immunotherapy and the novel contributions made by gut miRNAs to regulation of the host microbiome.

The microRNApolymorphisms inmiR-150 and miR-1179 are associated with risk of idiopathic recurrent pregnancy loss

RESEARCH QUESTION

Are single nucleotide polymorphisms of microRNAs (miRNAs) and risk of idiopathic recurrent pregnancy loss (RPL) associated?

DESIGN

A total 375 patients with idiopathic RPL (age, mean ± standard deviation [SD] 33.02 ± 4.24 years; body mass index [BMI], mean ± SD, 21.57 ± 3.70 kg/m²) and 276 control participants (age, mean ± SD, 33.01 ± 5.27 years; BMI, mean ± SD, 21.58 ± 3.20) were recruited. Pregnancy loss was diagnosed using human chorionic gonadotrophin concentrations, ultrasonography and/or physical examination prior to 20 weeks of gestation. The genotype of the participants was determined by polymerase chain reaction restriction fragment length polymorphism analysis. Statistical analysis was performed to investigate the differences in frequencies between the control and RPL genotypes RESULTS: The miR-150G>A heterozygous genotype was significantly associated with increased risk of RPL (adjusted odds ratio 2.502, 95% confidence interval 1.555-4.025; P = 0.0002). The miR-1179A>T heterozygous genotype was significantly associated with decreased risk of RPL (adjusted odds ratio 0.633, 95% confidence interval 0.454-0.884; P = 0.007). Some allele combinations that included miR-150A or miRNA-1179T resulted in an increase or decrease in risk of RPL, respectively.

CONCLUSIONS

The miR-150G>A and miR-1179A>T polymorphisms were more frequently associated with RPL compared with controls.

Predicting mucositis risk associated with cytotoxic cancer treatment regimens: rationale, complexity, and challenges

PURPOSE OF REVIEW

The goals of this review are to describe the complexity of factors influencing the risk of cancer regimen-related mucosal injury (CRRMI), to evaluate the contribution of the innate immune response to CRRMI risk, to compare the concordance of genome analytics in describing mechanism and risk, and to determine if common biological pathways are noted when CRRMI is compared to a disease with a similar phenotype.

RECENT FINDINGS

The pathogenesis of and risk for CRRMI are complex and influenced by multiple intrinsic and extrinsic factors. It is incumbent on analyses to recognize the likelihood that the interplay and cross-talk of synergistically expressed factors is critical and that the contributing weights of these factors is not uniform from patient to patient. Genomically derived analyses imply final common pathways are implicit in phenotype expression.

SUMMARY

The identification of specific factors (both genomic and otherwise) which contribute to CRRMI risk represents an important opportunity to apply principles of precision medicine to the management of regimen-related toxicities.

Pharmacogenomic and Pharmacotranscriptomic Profiling of Childhood Acute Lymphoblastic Leukemia: Paving the Way to Personalized Treatment

Personalized medicine is focused on research disciplines which contribute to the individualization of therapy, like pharmacogenomics and pharmacotranscriptomics. Acute lymphoblastic leukemia (ALL) is the most common malignancy of childhood. It is one of the pediatric malignancies with the highest cure rate, but still a lethal outcome due to therapy accounts for 1%⁻3% of deaths. Further improvement of treatment protocols is needed through the implementation of pharmacogenomics and pharmacotranscriptomics. Emerging high-throughput technologies, including microarrays and next-generation sequencing, have provided an enormous amount of molecular data with the potential to be implemented in childhood ALL treatment protocols. In the current review, we summarized the contribution of these novel technologies to the pharmacogenomics and pharmacotranscriptomics of childhood ALL. We have presented data on molecular markers responsible for the efficacy, side effects, and toxicity of the drugs commonly used for childhood ALL treatment, i.e., glucocorticoids, vincristine, asparaginase, anthracyclines, thiopurines, and methotrexate. Big data was generated using high-throughput technologies, but their implementation in clinical practice is poor. Research efforts should be focused on data analysis and designing prediction models using machine learning algorithms. Bioinformatics tools and the implementation of artificial i Lack of association of the CEP72 rs924607 TT genotype with intelligence are expected to open the door wide for personalized medicine in the clinical practice of childhood ALL.

Variants in vincristine pharmacodynamic genes involved in neurotoxicity at induction phase in the therapy of pediatric acute lymphoblastic leukemia

Vincristine is an important drug of acute lymphoblastic leukemia (ALL) treatment protocols that can cause neurotoxicity. Patients treated with LAL/SHOP protocols often suffer from vincristine-related neurotoxicity in early phases of treatment. A genetic variant in CEP72, a gene involved in vincristine pharmacodynamics, was recently associated with neurotoxicity after prolonged vincristine treatment. This association was not replicated in our Spanish population during induction phase. To test the possibility that other variants in genes involved in vincristine pharmacodynamics were associated with vincristine neuropathy in early phases of the treatment, we evaluated the correlation with toxicity of 24 polymorphisms in 9 key genes in a large cohort of 152 Spanish children with B-ALL homogeneously treated. Results showed no association between any genetic variant in the TUBB1, TUBB2A, TUBB2B, TUBB3, TUBB4, MAPT, MIR146a, MIR202, and MIR411 genes and vincristine-related neurotoxicity. These results are in line with the hypothesis that there are different mechanisms causing pheripheral neurotoxicity after prolonged and short-term vincristine treatments.

The Association of rs2114358 in the miR-1206 Polymorphism to Chronic Myeloid Leukemia

INTRODUCTION

Association studies with factor candidates have advised that single nucleotide polymorphisms (SNPs) could also be related to CML progression and to the response to medical care. Genetic variation in miR-1206 of both derived and neighborhood SNPs process genes will contribute to the predisposition to cancer. The role of those with the risk of CML has not been extensively studied. Therefore, the aim of this study was to evaluate whether polymorphisms in rs2114358 in pre-miRNAs process genes contribute to the risk of CML.

METHODS

A cross-sectional study was conducted during the period of March 2016 to October 2017 in Khartoum state teaching hospitals. The study population included a total of 420 patients who were previously diagnosed of having CML and 220 cancer-free controls of both gender and were of the same age range. Peripheral blood and bone marrow aspiration samples were collected from patients (254 males, 166 females; median age 58.5 years, range from less than 50 and above 50 years old) and investigated after written informed consent was obtained. Patients were in chronic phase (n=212), accelerated phase (n=125), and blast (n=83). All the patients were under treatment using chemotherapy regiments. The rs2114358 SNP in pre-miRNA was selected for genotyping.

RESULTS

The genotyping success rate was 98.3%. Genotype frequencies of the derived SNP and the neighborhood rs2114358 of miR-1206 compared to the controls were significantly different under Hardy-Weinberg Equilibrium (P=0.0001 and 0.0001 respectively). Significant differences were found in allele distributions of this SNP (P<0.01 and P<0.01). In total, the derived variant C allele of rs2114358 (OR=0.168, 95% CI=0.13-0.22) and G allele of neighborhood rs2114358 (OR=0.561, 95% CI=0.44-0.72) in patients' group were associated with an increased risk of CML compared to a control group. Patients with rs2114358 CC genotype (P = 0.0001) or TC (P = 0.0001) and the neighborhood rs2114358 GA genotype (P = 0.0460) or GG (P = 0.0093) were obviously much higher than that of the TT and AA genotype's patients.

CONCLUSION

In conclusion, we discovered the association of SNP rs2114358 in miR-1206 with the risk of CML patients, though more investigations are still required to understand the regulative mechanisms of this miR SNP with the target genes resulting in its dysregulation.

Involvement of miRNA polymorphism in mucositis development in childhood acute lymphoblastic leukemia treatment

Aim: Mucositis, linked to methotrexate, daunorubicin or cyclophosphamide, is a frequent childhood acute lymphoblastic leukemia (ALL) therapy side effect. miRNAs regulate the expression of pharmacokinetic/pharmacodynamic pathway genes. SNPs in miRNAs could affect their levels or function, and affect their pharmacokinetic/pharmacodynamic pathway target genes. Our aim was to determine the association between miRNA genetic variants targeting mucositis-related genes and mucositis-developing risk. Patients & methods: We analyzed 160 SNPs in 179 Spanish children with B-cell precursor ALL homogeneously treated with LAL/SHOP protocols. Results: We identified three SNPs in miR-4268, miR-4751 and miR-3117 associated with mucositis, diarrhea and vomiting, respectively. Conclusion: The effect of these SNPs on genes related to drug pharmacokinetics/pharmacodynamics could explain mucositis, diarrhea and vomiting development during ALL therapy.

miR-300 rs12894467 polymorphism may be associated with susceptibility to primary lung cancer in the Chinese Han population

Objective

The etiology of lung cancer has been attributed to both environmental and genetic factors. In this study, we investigated the association between five miRNA gene single-nucleotide polymorphisms (SNPs) and the risk of lung cancer, and explored the interaction between genetic and environmental factors in the Han people of China, the ethnic group that represents >90% of the population of the country.

Methods

This case–control study included 1,067 cases and 1,085 controls. Epidemiological data were collected by in-person interviews using a standard questionnaire. Matrix-assisted laser desorption/ionization time of flight mass spectrometry was applied to genotype the selected miRNA gene SNPs. Unconditional logistic regression and stratified analysis were used to analyze the associations between these SNPs and lung cancer, and to calculate the adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Crossover analysis, logistic regression, and the Excel table made by Andersson were used to analyze the combined and interaction effects of gene–environment.

Results

The rs12894467 CC/CT genotype was associated with a significantly increased risk for lung cancer in women (adjusted OR =1.46, 95% CI=1.01–2.10). Smokers carrying the CC/ CT genotype were associated with a significantly decreased risk of lung cancer, the adjusted OR was 0.75 (95% CI: 0.57–0.98). In the dominant model, rs12894467 and gender were associated with a positive multiplicative interaction; rs12894467 and smoking were associated with a negative multiplicative interaction.

Conclusion

The rs12894467 polymorphism was potentially associated with primary lung cancer in the Han Chinese population and had an interactive relationship with environmental factors.

The miR-1206 microRNA variant is associated with methotrexate-induced oral mucositis in pediatric acute lymphoblastic leukemia

Five-year survival rates of pediatric acute lymphoblastic leukemia (ALL) have reached 90% in the developed countries. However, toxicity because of methotrexate (MTX) occurs frequently. Variety in the occurrence of toxicity is partly determined by single nucleotide polymorphisms (SNPs) in coding regions. Recently, five SNPs in non-coding pre-microRNAs and microRNA processing (miRNA) genes were identified in association with MTX-induced oral mucositis. This study aimed to replicate the association of these miRNA variants in relation to MTX-induced oral mucositis in a prospective childhood ALL cohort. Three out of five SNPs with a minor allele frequency more than 0.15 [CCR4-NOT transcription complex (CNOT4) rs3812265, miR-1206 rs2114358, miR-2053 rs10505168] were analyzed in 117 pediatric ALL patients treated with 5 g/m MTX (DCOG ALL-10). Oral mucositis was defined as grade more than or equal to 3 according to the National Cancer Institute criteria. rs2114358 in miR-1206 was associated with oral mucositis [odds ratio (OR): 3.6; 95% confidence interval (CI): 1.1-11.5], whereas we did not confirm the association of CNOT4 rs3812265 (OR: 0.69; 95% CI: 0.27-1.80) and miR-2053 rs10505168 (OR: 2.50; 95% CI: 0.76-8.24). Our results replicate the association between rs2114358 in miR-1206 and MTX-induced oral mucositis in childhood ALL. Genetic variation in miR-1206 has potential as a novel biomarker to predict MTX-induced toxicity.

Pharmacoepigenetics in childhood acute lymphoblastic leukemia: involvement of miRNA polymorphisms in hepatotoxicity

AIM

Hepatotoxicity is one of the most common drug-related toxicities during the treatment of childhood acute lymphoblastic leukemia (ALL). Many genes involved in liver-specific signaling pathways are tightly controlled by miRNAs, and miRNA function could be modulated by SNPs. As a consequence, we hypothesized that variants in miRNAs could be associated with drug-induced hepatotoxicity.

METHODS

We analyzed 213 SNPs in 206 miRNAs in a cohort of 179 children with ALL homogeneously treated.

RESULTS

rs2648841 in miR-1208 was the most significant SNP during consolidation phase after false discovery rate correction, probably through an effect on its target genes DHFR, MTR and MTHFR.

CONCLUSION

These results point out the possible involvement of SNPs in miRNAs in toxicity to chemotherapy in children with ALL.

Role of miRNAs in treatment response and toxicity of childhood acute lymphoblastic leukemia

Childhood acute lymphoblastic leukemia survival rates have increased remarkably during last decades due, in part, to intensive treatment protocols. However, therapy resistance and toxicity are still two important barriers to survival. In this context, pharmacoepigenetics arises as a tool to identify new predictive markers, required to guide clinicians on risk stratification and dose individualization. The present study reviews current evidence about miRNA implication on childhood acute lymphoblastic leukemia therapy resistance and toxicity. A total of 12 studies analyzing differential miRNA expression in relation to drug resistance and six studies exploring the association between miRNAs-related SNPs and drug-induced toxicities were identified. We pointed out to miR-125b together with miR-99a and/or miR-100 overexpression as markers of vincristine resistance and rs2114358 in mir-1206 as mucositis marker as the most promising results.

The SNPs in pre-miRNA are related to the response of capecitabine-based therapy in advanced colon cancer patients

The single nucleotide polymorphisms (SNPs) in the microRNA precursor (pre-miRNA) may modulate the posttranscriptional regulation of gene expression and explain individual sensitivity to chemotherapy. Here we investigated the correlation between 23 SNPs in the pre-miRNA and the efficacy of capecitabine-based chemotherapy in 274 advanced colon cancer patients. Statistical analysis indicated that much more patients with rs744591 A/C(48.03%), C/C (53.45%) or C allele (49.73%) responded to the chemotherapy than those with the A/A genotype (33.71%). The response rates of rs745666 G/C heterozygous patients (35.25%) and C allele carriers (39.69%) were apparently less than that of the G/G homozygous patients (56.25%). Moreover, three SNPs rs2114358, rs35770269, and rs73239138 were significantly associated with the occurrence of side effects of chemotherapy. The patients with rs2114358 C allele (OR = 2.016) or rs35770269 T allele (OR = 2.299) were much more prone to endure adverse events. However, the incidence of side effect was lower in the patients carrying rs73239138 A allele than those with G/G genotype (OR = 0.500). Our findings demonstrate that genetic variations in pre-miRNA may influence the efficacy of capecitabine-based chemotherapy in advanced colon cancer patients.

Association between a microRNA binding site polymorphism in SLCO1A2 and the risk of delayed methotrexate elimination in Chinese children with acute lymphoblastic leukemia

Organic anion-transporting polypeptide 1A2 (OATP1A2) is involved in the cellular uptake of methotrexate (MTX). Genetic variation in solute carrier organic anion transporter family member 1A2 (SLCO1A2, the coding gene of OATP1A2) has important implications for the elimination of MTX. We investigated the association between a microRNA (miRNA) binding site polymorphism (rs4149009 G > A) in the 3'-untranslated region (3'-UTR) of SLCO1A2 with the serum MTX concentrations in Chinese children with acute lymphoblastic leukemia (ALL). Genotyping for SLCO1A2 rs4149009 G > A in 141 children with ALL was performed using the Sequenom MassARRAY system. Serum MTX concentrations were determined by fluorescence polarization immunoassay. The percentages of MTX level ≥1 μmol/L at 42 h were compared among the AA, GA, and GG genotypes. The minor allele frequency observed in this study (33.0%) was significantly lower than that in the African samples reported in the 1000 Genomes Project (57.4%, P = 0.00). The incidence rate of delayed MTX elimination was significantly higher in patients with the GG genotype (23.1%) compared with the AA genotype (0.0%, P = 0.03). Bioinformatics tools predicted that the rs4149009 A allele would disrupt the putative binding sites of hsa-miR-324-3p and hsa-miR-1913. These results indicate that the rs4149009 G > A polymorphism might affect MTX pharmacokinetics by interfering with the function of miRNAs.

Review of pharmacogenetics studies of L-asparaginase hypersensitivity in acute lymphoblastic leukemia points to variants in the GRIA1 gene

Acute lymphoblastic leukemia (ALL) is a major pediatric cancer in developed countries. Although treatment outcome has improved owing to advances in chemotherapy, there is still a group of patients who experience severe adverse events. L-Asparaginase is an effective antineoplastic agent used in chemotherapy of ALL. Despite its indisputable indication, hypersensitivity reactions are common. In those cases, discontinuation of treatment is usually needed and anti-asparaginase antibody production may also attenuate asparaginase activity, compromising its antileukemic effect. Till now, six pharmacogenetic studies have been performed in order to elucidate possible genetic predisposition for inter-individual differences in asparaginase hypersensitivity. In this review we have summarized the results of those studies which describe the involvement of four different genes, being polymorphisms in the glutamate receptor, ionotropic, AMPA 1 (GRIA1) the most frequently associated with asparaginase hypersensitivity. We also point to new approaches focusing on epigenetics that could be interesting for consideration in the near future.

Multiphenotype association study of patients randomized to initiate antiretroviral regimens in AIDS Clinical Trials Group protocol A5202

Supplemental Digital Content is available in the text.

Background

High-throughput approaches are increasingly being used to identify genetic associations across multiple phenotypes simultaneously. Here, we describe a pilot analysis that considered multiple on-treatment laboratory phenotypes from antiretroviral therapy-naive patients who were randomized to initiate antiretroviral regimens in a prospective clinical trial, AIDS Clinical Trials Group protocol A5202.

Participants and methods

From among 5 9545 294 polymorphisms imputed genome-wide, we analyzed 2544, including 2124 annotated in the PharmGKB, and 420 previously associated with traits in the GWAS Catalog. We derived 774 phenotypes on the basis of context from six variables: plasma atazanavir (ATV) pharmacokinetics, plasma efavirenz (EFV) pharmacokinetics, change in the CD4+ T-cell count, HIV-1 RNA suppression, fasting low-density lipoprotein-cholesterol, and fasting triglycerides. Permutation testing assessed the likelihood of associations being by chance alone. Pleiotropy was assessed for polymorphisms with the lowest P-values.

Results

This analysis included 1181 patients. At P less than 1.5×10⁻⁴, most associations were not by chance alone. Polymorphisms with the lowest P-values for EFV pharmacokinetics (CYPB26 rs3745274), low-density lipoprotein -cholesterol (APOE rs7412), and triglyceride (APOA5 rs651821) phenotypes had been associated previously with those traits in previous studies. The association between triglycerides and rs651821 was present with ATV-containing regimens, but not with EFV-containing regimens. Polymorphisms with the lowest P-values for ATV pharmacokinetics, CD4 T-cell count, and HIV-1 RNA phenotypes had not been reported previously to be associated with that trait.

Conclusion

Using data from a prospective HIV clinical trial, we identified expected genetic associations, potentially novel associations, and at least one context-dependent association. This study supports high-throughput strategies that simultaneously explore multiple phenotypes from clinical trials’ datasets for genetic associations.

microRNAs Make the Call in Cancer Personalized Medicine

Since their discovery and the advent of RNA interference, microRNAs have drawn enormous attention because of their ubiquitous involvement in cellular pathways from life to death, from metabolism to communication. It is also widely accepted that they possess an undeniable role in cancer both as tumor suppressors and tumor promoters modulating cell proliferation and migration, epithelial-mesenchymal transition and tumor cell invasion and metastasis. Moreover, microRNAs can even affect the tumor surrounding environment influencing angiogenesis and immune system activation and recruitment. The tight association of microRNAs with several cancer-related processes makes them undoubtedly connected to the effect of specific cancer drugs inducing either resistance or sensitization. In this context, personalized medicine through microRNAs arose recently with the discovery of single nucleotide polymorphisms in the target binding sites, in the sequence of the microRNA itself or in microRNA biogenesis related genes, increasing risk, susceptibility and progression of multiple types of cancer in different sets of the population. The depicted scenario implies that the overall variation displayed by these small non-coding RNAs have an impact on patient-specific pharmacokinetics and pharmacodynamics of cancer drugs, pushing on a rising need of personalized treatment. Indeed, microRNAs from either tissues or liquid biopsies are also extensively studied as valuable biomarkers for disease early recognition, progression and prognosis. Despite microRNAs being intensively studied in recent years, a comprehensive review describing these topics all in one is missing. Here we report an up-to-date and critical summary of microRNAs as tools for better understanding personalized cancer biogenesis, evolution, diagnosis and treatment.

ABCB1 genetic variants in leukemias: current insights into treatment outcomes

Despite improvements in treatment of different types of leukemia, not all patients respond optimally for a particular treatment. Some treatments will work better for some, while being harmful or ineffective for others. This is due to genetic variation in the form of single-nucleotide polymorphisms (SNPs) that affect gene expression or function and cause inherited interindividual differences in the metabolism and disposition of drugs. Drug transporters are one of the determinants governing the pharmacokinetic profile of chemotherapeutic drugs. The ABCB1 transporter gene transports a wide range of drugs, including drugs used in leukemia treatment. Polymorphisms in the ABCB1 gene do affect intrinsic resistance and pharmacokinetics of several drugs used in leukemia treatment protocols and thereby affect the efficacy of treatment and event-free survival. This review focuses on the impact of three commonly occurring SNPs (1236C>T, 2677G>T/A, and 3435C>T) of ABCB1 on treatment response of various types of leukemia. From the literature available, some of the genotypes and haplotypes of these SNPs have been found to be potential determinants of interindividual variability in drug disposition and pharmacologic response in different types of leukemia. However, due to inconsistencies in the results observed across the studies, additional studies, considering novel genomic methodologies, comprehensive definition of clinical phenotypes, adequate sample size, and uniformity in all the confounding factors, are warranted.

Pharmacogenomics in pediatric acute lymphoblastic leukemia: promises and limitations

Despite the significant advances achieved in pediatric acute lymphocytic leukemia (ALL) treatment, adverse side effects of drugs remain a challenging issue. Numerous ALL pharmacogenomic studies have been conducted to elucidate the predisposing genetic factors for their development. Plausible pharmacogenomic data are available for the osteonecrosis associated with glucocorticoids, the neurotoxicity associated with vincristine and the cardiotoxicity related to anthracyclines. However, these data have not been fully translated into the clinic due to several limitations, most importantly the lack of reliable evidence. The most robust pharmacogenomics data are those for thiopurines and methotrexate use, with evidence-based preemptive testing recommendations for the former. Pharmacogenomics has a significant potential utility in pediatric ALL treatment regimens. In this review, gaps and limitations in this field are emphasized, which may provide a useful guide for future research design.

MTHFR polymorphisms in childhood acute lymphoblastic leukemia: influence on methotrexate therapy

Methotrexate (MTX) is an important component in the therapy used to treat childhood acute lymphoblastic leukemia (ALL). Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme for MTX pharmacokinetics. Two single-nucleotide polymorphisms in MTHFR gene, C677T and A1298C, affecting MTHFR activity, have been widely studied as potential markers of MTX toxicity and/or outcome in pediatric ALL. In this review, we show that the majority of published reports do not find association or present opposite effect. Therefore, MTHFR C677T and A1298C polymorphisms do not seem to be good markers of MTX-related toxicity and/or outcome in pediatric ALL. The efforts should be focused on other genes, such as transporter genes or microRNA-related genes.

Vincristine pharmacokinetics pathway and neurotoxicity during early phases of treatment in pediatric acute lymphoblastic leukemia

AIM

Vincristine is an important component of acute lymphoblastic leukemia (ALL) treatment protocols that can cause neurotoxicity. Patients treated with LAL/SHOP protocols often suffer from vincristine-related neurotoxicity in early phases of treatment. Recently, a genome-wide association study connected a SNP in CEP72, involved in vincristine pharmacodynamics, with neurotoxicity during later phases of therapy, which was not replicated during induction phase. These results, together with previous studies indicating that polymorphisms in pharmacokinetic genes are associated with drug toxicity, suggest that changes in the activity or levels of vincristine transporters or metabolizers could work as predictors of vincristine-related neurotoxicity in early phases of treatment in pediatric ALL.

PATIENTS & METHODS

We analyzed 150 SNPs in eight key genes involved in vincristine pharmacokinetics and in 13 miRNAs that regulate them. We studied their correlation with neurotoxicity during induction phase in 152 ALL patients treated with LAL/SHOP protocols.

RESULTS

The strongest associations with neurotoxicity were observed for two SNPs in ABCC2. The genotypes rs3740066 GG and rs12826 GG were associated with increased neurotoxicity.

CONCLUSION

Polymorphisms in ABCC2 could be novel markers for vincristine-related neurotoxicity in pediatric ALL in early phases.

Circulating microRNA predicts insensitivity to glucocorticoid therapy in Graves' ophthalmopathy

Glucocorticoid (GC) insensitivity occurs commonly in Graves' ophthalmopathy (GO), and GC therapy is associated with major adverse effects. A reliable and easily accessible biomarker is required to predict the outcome of GC therapy. This study aimed to evaluate the performance of circulating microRNA (miRNA) to predict GC insensitivity in GO patients. A total of 35 consecutive patients were included in this study. A cumulative dose of 4.5 g of methylprednisolone (MP) was administered intravenously for 12 weeks. Pretreatment serum miRNAs from the best- (N = 5) and worst- (N = 4) responding patients were profiled using miScript PCR arrays and validated by quantitative PCR in all patients. We calculated the predictive value of pretreatment assays of serum miRNAs with regard to GC insensitivity. We further investigated the roles of target miRNAs in modulating NF-κB activity and restoring transrepression of an NF-κB reporter by dexamethasone. Nine miRNAs displayed significant differences between responsive and resistant patients by miScript PCR arrays. Validation of the top two miRNAs in all 35 patients confirmed a significantly lower serum level of miR-224-5p (p = 0.0048) in resistant patients. A multivariate logistic regression model identified a composite biomarker combining baseline serum miR-224-5p and TRAb was independently associated with GC response (OR: 2.565, 95 % CI 1.011-6.505, p = 0.047). Receiver operating characteristic (ROC) curves analysis revealed the composite marker combining miR-224-5p and TRAb led to a 91.67 % positive prediction value (PPV) and a 69.56 % negative prediction value (NPV) with regard to GC resistance. Overexpression of miR-224-5p restored transrepression of the NF-κB reporter by dexamethasone under induced resistance, which may be via targeting GSK-3β to increase GR protein level. Our study demonstrated baseline serum miR-224-5p was associated with GC sensitivity in GO and in vitro overexpression of miR-224-5p restored GC sensitivity in a resistant cell model. A parameter combined serum miR-224-5p and TRAb could effectively predict GC sensitivity in GO patients.

Pharmacogenetics predictive of response and toxicity in acute lymphoblastic leukemia therapy

Acute lymphoblastic leukemia (ALL) is a relatively rare disease in adults accounting for no more than 20% of all cases of acute leukemia. By contrast with the pediatric population, in whom significant improvements in long term survival and even cure have been achieved over the last 30years, adult ALL remains a significant challenge. Overall survival in this group remains a relatively poor 20-40%. Modern research has focused on improved pharmacokinetics, novel pharmacogenetics and personalized principles to optimize the efficacy of the treatment while reducing toxicity. Here we review the pharmacogenetics of medications used in the management of patients with ALL, including l-asparaginase, glucocorticoids, 6-mercaptopurine, methotrexate, vincristine and tyrosine kinase inhibitors. Incorporating recent pharmacogenetic data, mainly from pediatric ALL, will provide novel perspective of predicting response and toxicity in both pediatric and adult ALL therapies.

MicroRNA polymorphisms as markers of risk, prognosis and treatment response in hematological malignancies

MicroRNA dysregulation is a common event in hematological malignancies. Apart from genomic and epigenetic alterations, miRNA networks may be disturbed by polymorphisms in the miRNA regulatory pathway (miRSNPs). In this review we provide an overview of three categories of miRSNPs: (1) SNPs in genes involved in miRNA biogenesis and processing; (2) SNPs in miRNA genes; and (3) SNPs in miRNA binding sites in target genes and discuss their potential role as markers of disease risk, prognosis and treatment response in hematological cancers. Although so far only the tip of the iceberg has been touched, studies of polymorphisms in the miRNA regulatory pathways have already provided some clues for the mechanisms of miRNA dysregulation in cancer and open new perspectives in the management of hematological malignancies.

Pharmacogenetics of childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the major pediatric cancer in developed countries. Although treatment outcome has improved owing to advances in chemotherapy, there is still a group of patients for which therapy fails while some patients experience severe toxicity. In the last few years, several pharmacogenetic studies have been performed to search for markers of outcome and toxicity in pediatric ALL. However, to date, TPMT is the only pharmacogenetic marker in ALL with clinical guidelines for drug dosing. In this article, we will provide an overview of the most important findings carried out in pharmacogenetics for pediatric ALL, such as the interest drawn by methotrexate transporters in the context of methotrexate treatment. Even if most of the studies are centered on coding genes, we will also point to new approaches focusing on noncoding regions and epigenetic variation that could be interesting for consideration in the near future.