Genetic risk factors for glucocorticoid-induced osteonecrosis: a meta-analysis

The hidden dangers of short-term glucocorticoid use in children: A genomic analysis

OBJECTIVE

Glucocorticoid (GC) administration has been associated with adverse drug reactions (ADRs) affecting multiple organ systems. While long-term use is widely recognized as a significant independent predictor of ADRs, it is important to note that even short-term use can lead to serious ADRs. The considerable inter-individual variability in ADRs occurrence may be influenced by genetic factors. This study, we present a case of a child who experienced significant weight gain and osteoporosis, following a brief administration of GC.

METHODS

To comprehensively investigate the underlying mechanisms, we conducted a genomic analysis utilizing the whole exome sequencing (WES) technique. This analysis encompassed the examination of phase I and phase II metabolism, influx transport, efflux transport, and drug targeting. Additionally, a comprehensive analysis was conducted on a cohort of 52,119 children to determine their ABCB1 rs1045642 genotype, and an additional 37,884 children were tested for their CYP3A5 rs776746 genotype.

RESULTS

The pharmacogenetic analysis unveiled the presence of a high-risk variant in ABCB1 rs1045642 and a slow metabolism variant in CYP3A5 rs776746, both of which have the potential to substantially contribute to ADRs. The findings of this study indicate that the prevalence of ABCB1 rs1045642 CT type among patients was 47.58%, with TT type accounting for 15.69 % and CC type accounting for 36.73 %. Furthermore, the distribution of CYP3A5 rs776746 CC genotype was observed in 50.54 % of individuals, while CT and TT genotypes were present in 41.15 % and 8.31 % of the population respectively. The distribution of ABCB1 and CYP3A5 genotypes among the pediatric population in China displays notable features. Specifically, for the ABCB1 rs1045642 genotype, less than 50 % of children exhibit intermediate metabotypes. Conversely, among children with the CYP3A5 rs776746 genotype, the predominant cause for enzyme activity is the slow metabolic type, accounting for up to 90 % of cases.

CONCLUSIONS

Consequently, it is imperative to thoroughly evaluate the impact of allele mutation on the effectiveness and safety of glucocorticoid drugs or other medications metabolized by the ABCB1 and CYP3A5, particularly in the context of Chinese pediatric patients.

Integrative analyses of genes related to femoral head osteonecrosis: an umbrella review of systematic reviews and meta-analyses of observational studies

Background

Femoral head osteonecrosis (FHON) is a worldwide challenging clinical topic. Steroid use is one of the main etiologies of FHON. There are several genetic variants associated with FHON. Therefore, the purpose of this umbrella review was to provide a comprehensive summary of a meta-analysis and systematic review of genetic variations associated with nonsteroidal and steroid-induced FHON.

Methods

The eligible studies were selected from the PubMed and MEDLINE databases for the collection of diverse systematic meta-analyses and reviews. The genetic main effect score was assigned using the Human Genome Epidemiology Network’s Venice criteria to assess the cumulative evidence on the effects of a single nucleotide polymorphism (SNP) on FHON.

Results

Eight articles reported the meta-analysis of candidate SNP-based studies covering eight genes and 13 genetic variants. In the nonsteroid-induced FHON genetic variants including rs2012390 and rs11225394 in MMP8, rs1800629 and rs361525 in tumor necrosis factor (TNF)-α, VNTR in intron 4, rs1799983 and rs2070744 in endothelial nitric oxide synthase (eNOS), rs2010963 in vascular endothelial growth factor (VEGF), and rs6025 in factor V showed significance in each reference. The steroid-induced FHON genetic variants including rs693 and rs1042031 in apolipoprotein (Apo)B, rs1045642 in ABCB1, and rs1799889 in PAI-1 showed significance in each reference.

Conclusion

Based on the systematic review conducted in this study, we organized the genomes associated with FHON and looked at each contribution. Our results could give an integrative approach for understanding the mechanism of FHON etiology. It is expected that these results could contribute to the strategy of prediagnosis, evaluating the individual risk of nonsteroid-induced and steroid-induced FHON.

Level of Evidence: Level I.

Concurrence of osteonecrosis and steroid myopathy secondary to oral steroid therapy in a patient with ABCB1 gene polymorphisms: A case report

Glucocorticoids (GCs) are widely used in various autoimmune diseases. Side effects may occur in patients with long-term or high-dose GC usage. Among them, steroid myopathy and osteonecrosis are two severe forms. We report a patient with pemphigus vulgaris on GC-treatment who developed muscle weakness when a cumulative dose of methylprednisolone reached about 20g (14-80mg/d for 2.5 years). Laboratory tests showed slightly elevated lactate dehydrogenase and hydroxybutyrate dehydrogenase. MRI revealed osteonecrosis in the femoral head, distal femur, and proximal tibia of both legs. The biopsy of the right quadriceps revealed atrophy of type II myofiber without leukocyte infiltration, which was suggestive of steroid myopathy. Genotyping of the patient showed 5G/5G genotype of the PAI-1 gene and CC genotype of the ABCB1 gene (C3435T), suggesting she was sensitive to GCs. The patient's lesions were considered to be GC-induced adverse events, which were improved with tapering GC. Therefore, it is important to recognize steroid-induced musculoskeletal side effects and genotyping favors personalized medication.

Quantile-specific heritability of plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) and other hemostatic factors

BACKGROUND

Plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) is a moderately heritable glycoprotein that regulates fibrin clot dissolution (fibrinolysis).

OBJECTIVES

Test whether the heritabilities (h2 ) of PAI-1 and other hemostatic factors are constant throughout their distribution or whether they are quantile-specific (i.e., a larger or smaller h2 depending on whether their concentrations are high or low).

METHODS

Quantile regression was applied to 5606 parent-offspring pairs and 5310 full siblings of the Framingham Heart Study. Quantile-specific heritability was estimated from the parent-offspring regression slope (βPO , h2  = 2βPO /(1+rspouse )) and the full-sib regression slope (βFS , h2  = {(1+8rspouse βFS )0.5 -1}/(2rspouse )).

RESULTS

Heritability (h2  ± SE) increased significantly with increasing percentiles of the offspring's age- and sex-adjusted PAI-1 distribution when estimated from βPO (plinear trend  = 0.0001): 0.09 ± 0.02 at the 10th, 0.09 ± 0.02 at the 25th, 0.16 ± 0.02 at the 50th, 0.29 ± 0.04 at the 75th, and 0.26 ± 0.08 at the 90th percentile of the PAI-1 distribution, and when estimated from βFS (plinear trend  = 6.5x10-7 ). There was no significant evidence for quantile-specific heritability for factor VII (plinear trend  = 0.35), D-dimer (plinear trend  = 0.08), tPA (plinear trend  = 0.74), or von Willebrand factor (plinear trend  = 0.79).

CONCLUSION

Higher mean plasma PAI-1 antigen concentrations tend to accentuate genetic effects (quantile-dependent expressivity), which is consistent with the greater reported differences in PAI-1 concentrations between rs1799889 SERPINE1 (4G/5G) genotypes in patients with osteonecrosis, meningococcal sepsis, obesity, prior myocardial infarction, deep vein thrombosis, and polycystic ovarian syndrome than in healthy controls. It is also consistent with the greater increases in PAI-1 concentrations in 4G-allele carriers than 5G/5G homozygotes following fibrinolytic treatment, low-salt intake, and high saturated fat intake.

Association of ABCB1 and CYP450 Gene Polymorphisms and their DNA Methylation Status with Steroid-Induced Osteonecrosis of the Femoral Head in the Chinese Population

Objective: Osteonecrosis of the femoral head (ONFH) is a severe pathological state with multiple etiologies. Steroid hormone metabolism-related genes play an important role in ONFH. The aim of this study was to investigate the relationships between polymorphisms of the drug-metabolizing enzyme gene, cytochrome P450 (CYP450), and the drug transporter gene, ATP-binding cassette subfamily B member 1 (ABCB1), as well as their DNA methylation status with the pathogenesis of steroid-induced ONFH. Methods: In this case-control study, we evaluated five single nucleotide polymorphisms (SNPs) in two genes in a Han Chinese population, including 79 patients with steroid-induced ONFH and 114 persons who took steroids but did not develop steroid-induced ONFH. SNPs were genotyped by the improved multiplex ligation detection reaction. MethylTarget technology was used to ascertain the methylation status at two CpG islands in the ABCB1 gene for statistical analysis. Finally, interactions between the SNPs and the CpG site's methylation levels were statistically analyzed by methylation quantitative trait locus. Results: We found that the T allele of the CYP450 rs2242480 locus was associated with steroid-induced ONFH risk reduction (odds ratio [OR] = 0.598, 95% confidence interval [CI]: 0.360-0.992, p = 0.046). In the genetic model analysis, the T allele of the rs2032582 locus in the ABCB1 gene was associated with a reduced risk of steroid-induced ONFH under the dominant model (OR = 0.465, 95% CI: 0.223-0.972, p = 0.042). The CpG sites with significant differences (p < 0.05) in methylation levels between the cases and controls were ABCB1_1_192…ABCB1_2_43. A total of 14 pairs of linear regression tests between SNPs and methylation sites demonstrated statistical significance (p < 0.05). Conclusions: This study provides evidence for two steroid-induced ONFH susceptibility genes (ABCB1, CYP450) in the Han Chinese population.

Glucocorticoids decreased Cx43 expression in osteonecrosis of femoral head: The effect on proliferation and osteogenic differentiation of rat BMSCs

Glucocorticoid (GC)‐induced osteonecrosis of the femoral head (GC‐ONFH) is considered as one of the most serious side effects of long‐term or over‐dose steroid therapy. However, the underlying cause mechanisms are still not fully investigated. We firstly established a rat model of GC‐ONFH and injected lipopolysaccharide (LPS) and methylprednisolone (MPS). We found that the expressions of Cx43, Runx2, ALP and COLⅠ were more decreased than the normal group. Secondly, the isolated rat bone marrow stem cells (BMSCs) were treated with dexamethasone (Dex) in vitro, and the expressions of Cx43, Runx2, ALP and COLⅠ were decreased significantly. Moreover, the results of immunofluorescence staining, alizarin red staining, EdU assay and CCK8 showed that the osteogenic differentiation and the proliferation capacity of BMSCs were decreased after induced by Dex. A plasmid of lentivirus‐mediated Cx43 (Lv‐Cx43) gene overexpression was established to investigate the function of Cx43 in BMSCs under the Dex treatment. Findings demonstrated that the proliferation and osteogenic differentiation abilities were enhanced after Lv‐Cx43 transfected to BMSCs, and these beneficial effects of Lv‐Cx43 were significantly blocked when PD988059 (an inhibitor of ERK1/2) was used. In conclusion, the overexpression of Cx43 could promote the proliferation and osteogenic differentiation of BMSCs via activating the ERK1/2 signalling pathway, which provide a basic evidence for further study on the detailed function of Cx43 in GC‐ONFH.

Association between genetic polymorphisms and osteonecrosis in steroid treatment populations: a detailed stratified and dose-response meta-analysis

Steroid treatment has become recognized as an important risk factor for avascular osteonecrosis of the femoral head. However, not all patients who receive long-term, high-dose steroids develop osteonecrosis, indicating that there are individual differences in occurrence.We explored the relationship between polymorphisms and steroid-induced osteonecrosis of the femoral head (SONFH) incidence with variables. We used a multilevel mixed-effects logistic regression model, which is an expansion of logistic regression, for each type of steroid, primary disease, drug dose, applied duration, and single-nucleotide polymorphism (SNP). We also conducted a dose-response meta-analysis to analyze the cumulative dosage and SONFH risk in mutation carriers. There were significant correlations between the ABCB1 rs1045642 mutant and SONFH in the prednisone-use and methylprednisolone/prednisone-use populations. The ABCB1 rs2032582 mutant homozygote had a protective effect in the methylprednisolone/prednisolone renal transplant population. For ApoB rs693, mutation increased the incidence of SONFH in prednisone-use and methylprednisolone/prednisolone-use populations and renal transplant patients. For ApoB rs1042031, mutation increased the risk of SONFH in the prednisone-use population. The PAI-1 rs1799768 mutation had a protective effect on the SONFH risk prednisone-use and renal transplant populations. ABCB1 rs1045642 mutations have a protective effect against SONFH, and ApoB rs693 and rs1042031 increase the SONFH risk. Cumulative dosage and treatment duration had little effect on the results. In addition, there was a dose-effect correlation in ABCB1 rs1045642 and rs2032582 mutation carriers.

Dose-related histopathology and bone remodeling characteristics of the knee articular cartilage and subchondral bone induced by glucocorticoids in rats

The aim of the current study was to investigate histopathological changes and bone remodeling in the knee articular cartilage and subchondral bone in rats following treatment with glucocorticoids. A total of 30 3-month-old female Sprague-Dawley rats were randomly divided into either a vehicle control group or one of three experimental groups wherein dexamethasone (Dex) was administered at a dose of 1.0, 2.5 or 5.0 mg/kg (Dex1.0, Dex2.5 and Dex5.0, respectively), for 8 weeks. Articular cartilage and the epiphyseal subchondral bone of the proximal tibias were evaluated by histopathology or for bone remodeling using histomorphometry. No histological changes were identified in the knee articular cartilage but the bone formation rate of the subchondral bone was lower in the Dex1.0 group compared with that of the control group. Compared with the control and the Dex1.0 group, the width of the articular cartilage and the subchondral plate were larger, with abnormal morphology and increased apoptosis of chondrocytes, decreased cell/matrix volume ratio in the cartilage and fewer blood vessels in the subchondral plate in the Dex2.5 and Dex5.0 groups. A higher Dex dose resulted in more severe inhibition of bone formation, a greater number of apoptotic osteocytes and constrained bone resorption. All microstructure parameters indicated no significant changes in the Dex2.5 group but exhibited deterioration in the Dex5.0 group compared with the normal and Dex1.0 group. There were no significant differences in morphological changes, or in static and dynamic bone indices between the Dex2.5 and Dex5.0 groups. In conclusion, long-term glucocorticoid use induced dose-related histopathological changes in the knee articular cartilage, along with unbalanced bone remodeling and osteopenia in the subchondral bone. The degree of damage to the articular cartilage was milder and transformed from compensation to degeneration at higher doses.

Long-term effects on growth, development, and metabolism of ALL treatment in childhood

INTRODUCTION

One aim of the long-term care in survivors from acute lymphoblastic leukemia (ALL) during childhood is to avoid or limit complications caused by aggressive therapeutic strategies.

AREAS COVERED

ALL survivors are a heterogeneous group according to therapeutic protocols. In the last decades, cranial radiotherapy (cRT) has been largely replaced by intrathecal chemotherapy (CT) with a reduction of endocrine sequelae. Published studies are generally difficult to be interpreted because patients were treated according to different risk-adapted protocols and results are conflicting. We perform this review on endocrine long-term effects in childhood ALL survivors focusing on studies published in the last decades. Articles were selected using the following terms (Mesh terms): 'acute lymphoblastic leukemia' AND 'survivors' AND 'childhood' AND 'growth/puberty/fertility/obesity/metabolic syndrome/bone'.

EXPERT COMMENTARY

Most childhood ALL survivors treated with CT alone attain normal height and have adequate pubertal development. Despite recent protocols improvements, ALL survivors still develop long-term metabolic complications (overweight, obesity, and cardiovascular disease) especially the female gender and patients with an increased body mass index (BMI) at diagnosis. The aim of this review is to describe the state of the art on these topics. We should be able to anticipate, prevent, and treat endocrine long-term morbidities through a well-established follow-up strategy.

Lipid Transporter Activity-Related Genetic Polymorphisms Are Associated With Steroid-Induced Osteonecrosis of the Femoral Head: An Updated Meta-Analysis Based on the GRADE Guidelines

Aims: The purpose of this study was to assess the relationship between genetic variants and steroid-induced osteonecrosis of the femoral head (SONFH) in steroid use populations. Methods: We searched the public databases up to April 15, 2018. This study analyzed only the single-nucleotide polymorphisms (SNPs) that have appeared in more than three studies and assessed the level of evidence by classifying the outcomes according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Results: The ABCB1 rs1045642 C>T mutation had a protective effect against SONFH in the allelic model (I ² = 50.2%; OR: 0.74; 95% CI: 0.55-1.00; p = 0.046). The rs2032582 mutation in the ABCB1 gene showed no relationship to SONFH (allelic model: I ² = 63.4%; OR: 0.85; 95% CI: 0.58-1.23; p = 0.382). In ApoB rs693, four models showed that mutations can increase SONFH risk, but the allelic model did not. The ApoB rs1042031 mutation increased SONFH risk in the dominant model (I ² = 50.3%; OR: 2.90; 95% CI: 1.49-5.66; p = 0.002). Conclusion: An allelic model of ABCB1 rs1045642 showed that mutations have a protective effect against SONFH at a very low level of evidence. The mutations in ApoB rs693 and rs1042031 increase the SONFH risk with moderate levels of evidence.

A Pharmacogenetic Study of VDR fok1 and TYMS Polymorphisms and Their Association With Glucocorticoid-Induced Osteonecrosis in Egyptian Children With Acute Lymphoblastic Leukemia

Purpose: Osteonecrosis is a significant toxicity resulting from the treatment of pediatric Acute Lymphoblastic Leukemia (ALL). This study aimed to investigate the relationship between vitamin D receptor fok1 (VDR fok1) and thymidylate synthase (TYMS) gene polymorphisms with the glucocorticoid (GC) induced osteonecrosis (ON) in Egyptian pediatric ALL patients. In addition, to identify the possible association of genetic polymorphisms with other factors such as gender and ALL subtypes.

Patients and Methods: A retrospective case-control study was conducted on 102 pediatric ALL patients under the age of 18 who were treated at Children Cancer Hospital Egypt according to St Jude SR/HR total XV protocol. The recruited patients were composed of 51 cases who developed GC-induced osteonecrosis and 51 age- and gender-matched patients who received glucocorticoids but remained osteonecrosis-free (controls). Genotyping of the VDR fok1 and TYMS genes was performed using restriction fragment length polymorphism (RFLP) and conventional PCR, respectively.

Results: For the total 102 studied patients, the VDR fok1 single nucleotide polymorphisms (SNPs) frequency distribution were TT (8.8%), CT (34.3%), and CC (56.9%), while the TYMS tandem repeat gene variations were reported as 2R2R (20.6%), 2R3R (45.1%), and 3R3R (34.3%). VDR fok1 and TYMS polymorphic variants showed no association neither with gender; P-values 0.3808 and 0.1503, respectively, nor with ALL subtypes; P-values 0.9396 and 0.6596, respectively. The VDR fok1 polymorphisms showed a significant association with the development of ON; P-value = 0.003, on the other hand, TYMS tandem repeats did not show significant impact on osteonecrosis development; P-value = 0.411.

Conclusion: This study showed a significant association between the VDR fok1 polymorphism and osteonecrosis. Such clinical pharmacogenetics results would be promising to discuss the possibility of dose adjustments aiming a regimen with the highest efficacy and least toxicity.

Different changes of microarchitectures of cortical and cancellous bones in sheep femoral head after long-term glucocorticoid interventions

This study investigatedthe different effects of long-term glucocorticoid (GC) interventions on the microarchitectures of cortical and cancellous bones of the femoral head. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 received prednisolone interventions (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 received the same interventions as Group 1 and then further observed 3 months without interventions. Control Group was left nonintervention. After killing the animals, all femoral heads were scanned by micro-CT to determine their microstructural properties. In cancellous bone of femoral head, GC interventions led to significant decrease of bone volume fraction, trabecular thickness, trabecular separation, but increase of structure model index and bone surface density (p < 0.05). While in cortical bone, there were no differences between the Group 1 and in microstructural properties (p > 0.05) except greater trabecular thickness in the control group. In addition, three months after cessation of glucocorticoid interventions, most microstructural properties of cancellous bone were significant reversed, but not cortical thickness of femoral head. In contrast to cancellous bone, the microarchitectures of cortical bone were not changed obviously after long-term GC interventions.

Recipient rs1045642 Polymorphism Is Associated With Office Blood Pressure at 1-Year Post Kidney Transplantation: A Single Center Pharmacogenetic Cohort Pilot Study

Background: Corticosteroids are associated with reduced bone mineral density (BMD), as well as water and salt retention, leading to hypertension. They are substrates for P-glycoprotein, a protein coded by the highly polymorphic ABCB1 gene. We hypothesized that one ABCB1 polymorphism, rs1045642, is associated with blood pressure and BMD parameters at 1-year post kidney transplantation (KT).

Methods: Rs1045642 was genotyped using pyrosequencing in 40 KT recipients. Both dominant (CC vs. CT + TT) and codominant (CC vs. CT vs. TT) genetic models (analysis of variance from linear regressions) were adjusted for confounding variables (age, sex, type of nephropathy, glomerular filtration rate, and corticosteroid use at 1 year).

Results: Rs1045642 genotypes were significantly associated with systolic (SBP) and diastolic (DBP) blood pressure 1-year post-transplantation, independent of the genetic model used (adjusted codominant model: SBP p-value = 0.015, DBP p-value = 0.038; adjusted dominant model: SBP p-value = 0.003, DBP p-value = 0.011). A non-statistically significant trend was observed for an association between rs1045642 and BMD change at 1-year post-KT.

Conclusions: Rs1045642 is significantly associated with higher BP 1 year after KT. Further investigations are necessary to confirm the role of rs1045642 in corticosteroid-related adverse effects.

Association between plasminogen activator inhibitor gene polymorphisms and osteonecrosis of the femoral head susceptibility: A case-control study

This study aimed to analyze the correlation of the plasminogen activator inhibitor (PAI-1) gene polymorphisms (rs6092 and rs7242) with susceptibility of osteonecrosis of the femoral head (ONFH).This case-control study included 106 ONFH patients and 151 healthy controls. PAI-1 polymorphisms were genotyped by polymerase chain reaction (PCR) with direct sequencing. The genotype distribution of polymorphism in the control group was checked with the status of Hardy-Weinberg equilibrium (HWE). The χ test was applied to compare the genotypes of polymorphisms between the case and control groups. The association intensity between PAI-1 polymorphisms and ONFH risk was estimated by odds ratios (ORs) and 95% confidence intervals (95% CI). The linkage disequilibrium of PAI-1 polymorphisms was analyzed by Haploview.We found that the genotypes and alleles of PAI-1 rs6092 and rs7242 polymorphisms had no obvious association with the risk of ONFH (P >.05). But the strong linkage disequilibrium existed between rs6092 and rs7242 polymorphisms and haplotype G-T was significantly associated with the decreased risk of ONFH occurrence (OR = 0.666, 95%CI = 0.445-0.998).PAI-1 rs6092 and rs7242 polymorphisms are not associated with ONFH development, but haplotype G-T may be a protective factor of ONFH.

TNF-α and LT-α polymorphisms and the risk of leukemia: a meta-analysis

AIM

The aim of this study is to investigate whether TNF-α or LT-α polymorphisms are associated with the risk of leukemia.

METHODS

A meta-analysis was performed to examine the association between the TNF-α -308 G&gt;A and LT-α +252 A&gt;G polymorphisms and the incidence of leukemia. We also performed subgroup analyses based on the classification of leukemias. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the association.

RESULTS

A total of 19 publications comprising 1,509 cases and 4,075 controls were selected in the study. An association between the risk of leukemia and the LT-α +252 AA genotype was found (GG + AG vs. AA, OR = 0.485, 95% CI 0.368-0.639, p = 0.000). After multivariable analysis TNF-α polymorphism showed no consistent association with leukemia.

CONCLUSIONS

This meta-analysis suggests that the LT-α +252 AA polymorphism is associated with the risk of leukemia.

Differential expression of miR-672-5p and miR-146a-5p in osteoblasts in rats after steroid intervention

BACKGROUND

Apoptosis of osteoblasts and osteocytes is one cause of steroid-induced osteonecrosis of the femoral head; however, the molecular mechanism of steroid affecting osteoblasts at the genetic level is unclear. The aim of the present work is to examine differential expression of osteoblasts in rats after steroid intervention and to verify expression by real-time polymerase chain reaction (RT-PCR).

METHODS

Primary culture, passaging and identification of osteoblasts of SD neonatal rats were conducted; osteoblasts were divided into two groups, the control group, and the steroid group. Total RNA was extracted separately, and quality control was performed; by means of RNA labeling and microarray hybridization, data were collected and then standardized to ascertain differences in miRNA expression between the two groups. The gene expression spectrum was analyzed. Obvious differential expression of miR-672-5p and miR-146a-5p was verified by RT-PCR. Miranda, microcosm and mirdb bioinformatics software were used to predict target genes.

RESULTS

Compared with the control group, morphologically, the osteoblasts in the steroid group were more irregular and showed various shapes. The number of miRNAs (fold change >2) in the steroid group was six. Four miRNAs were upregulated and two miRNAs were downregulated. In particular, upregulated miR-672-5p expression and downregulated miR-146a-5p expression were significant. RT-PCR results showed that the 2(-△△) CT value of miR-672-5p in the steroid group was 3.743-fold of that in the control group, and the 2(-△△) CT value of miR-146a-5p in the steroid group was 0.322-fold of that in the control group. Angptl4, Ccdc51, Ssbp3 and RGD1306991 were predicted as the target gene of miR-672-5p, while Hrp12 was that of miR-146a-5p.

CONCLUSION

Expression profiles of miR-672-5p and miR-146a-5p had the most significant changes in the osteoblasts of rats with steroid intervention, which may provide a new viewpoint to pathogenesis of osteonecrosis of the femoral head.

Incidence and outcome of osteonecrosis in children and adolescents after intensive therapy for acute lymphoblastic leukemia (ALL)

Osteonecrosis (ON), a significant complication following treatment of acute lymphoblastic leukemia (ALL), has a profound impact on quality of life of ALL survivors. We studied incidence and outcome of ON in patients treated on or according to Australian and New Zealand Children's Haematology/ Oncology Group (ANZCHOG) study 8 at The Children's Hospital at Westmead. The study involved retrospective chart review of the patients. ON was defined by development of symptoms and confirmed by magnetic resonance imaging. From 2002-2011, 251 patients (143M, 108F, 59 Standard Risk (SR), 159 Medium Risk (MR) 5 High Risk (HR), and 28 Very high risk (VHR)) were treated according to study 8. Eighteen (7M, 11F, 2 SR, 12 MR, 4 VHR) patients developed ON (7.2%). Median age at diagnosis was 13.05 years(4.3-16.7). Incidence of ON in patients > 10 years at diagnosis was 29%. Six out of 18 patients developed ON after allogeneic stem cell transplantation. Median time from diagnosis to the development of ON following chemotherapy for ALL was 1.15 years (range 0.25-2.12). Most patients were treated with intravenous Zoledronic acid. At last follow-up, three patients had undergone arthroplasty, two patients were symptom free, and the remaining 13 patients reported persistent pain with activity. A majority of patients with ON of the hips had radiological progression. Overall, 7% of patients with ALL developed ON. Age >10 years was the most important risk factor. At last follow-up, 70% of patients had persistent symptoms. Although Zoledronic acid improved pain, most patients with ON of the hips had radiological progression.

Inherited genetic variation in childhood acute lymphoblastic leukemia

Although somatically acquired genomic alterations have long been recognized as the hallmarks of acute lymphoblastic leukemia (ALL), the last decade has shown that inherited genetic variations (germline) are important determinants of interpatient variability in ALL susceptibility, drug response, and toxicities of ALL therapy. In particular, unbiased genome-wide association studies have identified germline variants strongly associated with the predisposition to ALL in children, providing novel insight into the mechanisms of leukemogenesis and evidence for complex interactions between inherited and acquired genetic variations in ALL. Similar genome-wide approaches have also discovered novel germline genetic risk factors that independently influence ALL prognosis and those that strongly modify host susceptibility to adverse effects of antileukemic agents (eg, vincristine, asparaginase, glucocorticoids). There are examples of germline genomic associations that warrant routine clinical use in the treatment of childhood ALL (eg, TPMT and mercaptopurine dosing), but most have not reached this level of actionability. Future studies are needed to integrate both somatic and germline variants to predict risk of relapse and host toxicities, with the eventual goal of implementing genetics-driven precision-medicine approaches in ALL treatment.

ABCB1 gene polymorphisms and glucocorticoid-induced avascular necrosis of the femoral head susceptibility: a meta-analysis

BACKGROUND

The results of studies on association between ABCB1 gene polymorphisms and glucocorticoid-induced avascular necrosis of the femoral head (GANFH) are controversial. This study aimed to assess the association of ABCB1 gene polymorphisms with the risk of GANFH by conducting a meta-analysis.

MATERIAL AND METHODS

The PubMed, Cochrane Library, and Embase databases were searched for papers that describe the association between ABCB1 polymorphisms and GANFH risk. Summary odds ratios and 95% confidence intervals (CI) were estimated based on a fixed-effects model or random-effects model, depending on the absence or presence of significant heterogeneity.

RESULTS

A total of 5 studies and 833 patients were included in the final analysis. Significant differences were found for rs1045642 polymorphism in the comparisons of CC vs. CT+TT (OR, 1.462; 95% CI, 1.066-2.007; P=0.019), and rs2032582 polymorphism in the comparisons of GG vs. G(TA)+(TA)(TA) (OR, 1.548; 95% CI,1.063-2.255; P=0.023).

CONCLUSIONS

The study demonstrated that the ABCB1 polymorphisms (rs1045642 and rs2032582) significantly reduced the risk of GANFH.

MDR1 gene polymorphisms are associated with glucocorticoid-induced avascular necrosis of the femoral head in a Chinese population

P-glycoprotein (P-gp) is present in various tissue cells, required for the pumping of lipophilic drugs (including glucocorticoids) out of cells. We hypothesized that polymorphisms in the P-gp encoding gene (multidrug-resistant transporter-1 [MDR1]) are related to individual differences in glucocorticoid sensitivity and the development of glucocorticoid-induced avascular necrosis of the femoral head (GANFH). In this case-control study, we genotyped three known single-nucleotide polymorphisms (SNPs: C1236T, G2677T/A, and C3435T) within the MDR1 gene in 662 Chinese subjects. Statistically significant differences between GANFH patients and either healthy controls or glucocorticoid-resistant patients (non-GANFH) were found for the T allele or TT genotype of C3435T. The haplotype TTT, composed of these three SNPs, exhibited a significant association with the disease. No associations were identified between C1236T or G2677T/A and GANFH. Our results suggest that the C3435T polymorphism of the MDR1 gene is associated with susceptibility to GANFH in a Chinese population.

The adolescent and young adult with cancer: state of the art-- acute leukemias

Despite survival gains over the past several decades, adolescent and young adult (AYA) patients with both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) demonstrate a consistent survival disadvantage. The AYA population exhibits unique disease and host characteristics, and further study is needed to improve their outcomes. This review will highlight distinctive aspects of disease biology in this population, as well as salient treatment-related toxicities including osteonecrosis, pancreatitis, thromboembolism, hyperglycemia, and infections. The impact of obesity and differences in drug metabolism and chemotherapy resistance will also be discussed, as well as optimal treatment considerations for the AYA population.