Hydroxyurea Research Articles

Microalbuminuria in Children With Sickle Cell Disease in the Eastern Province of Saudi Arabia.

Sickle cell disease (SCD) complications, such as sickle cell nephropathy (SCN), may begin in childhood and progress insidiously to chronic kidney disease in adulthood. In Saudi Arabia (SA), there is a lack of studies evaluating kidney function in children with SCD. This study aims to assess microalbuminuria (MA) as an early marker of renal dysfunction in SCD children living in the Eastern region of SA, to potentially institute appropriate early treatment. A prospective cross-sectional study was conducted on 114 Saudi children with SCD under the age of 14 years who attended the pediatric hematology clinic for routine follow-up. Demographic and clinical information were collected from the patients and their parents, who provided informed consent. Morning urine samples were collected and tested for the presence of MA using the urinary albumin/creatinine ratio (ACR). Blood samples were also collected for basic laboratory investigations. The prevalence of MA and its correlation with various clinical and laboratory data were analyzed. Additionally, a comparison of clinical characteristics and MA was conducted between children originating from the Southwestern (SW) and Eastern regions of the country, all of whom lived in the Eastern Province. A total of 114 children with SCD were included in the study. The mean age was 8.8 ± 3.2 years, with a male-to-female ratio of 1.3:1. Based on their region of origin, they were divided into two groups: Eastern (n = 26/114) and SW (n = 88/114). MA was detected in 28 patients (24.6%), with no significant difference in prevalence between the two groups. There was no significant statistical difference in clinical and laboratory data between the groups, except for hemoglobin F (HBF) levels and the use of hydroxyurea (HU). HBF levels were significantly higher in children from the Eastern region, while more SW patients used HU. No correlation was found between MA and any of the studied variables. MA is common in children with SCD in the Eastern region of SA, with no difference in its prevalence between children of the two different ancestries carrying the Arab-Indian (AI) and African haplotypes. It is not associated with any of the studied clinical variables in this report. Further studies are needed to confirm these findings.

Ascorbic acid regulates in vitro and in vivo toxicogenetic effects of hydroxyurea on eukaryotic cells

Hydroxyurea (HU) exerts unique and diverse biological effects as an anti-leukemic agent, irradiation sensitizer, and HbS inducer in patients with sickle cell anemia. Herein, we assessed the potential toxicogenic and/or oxidant effects of hydroxyurea associated with ascorbic acid by in vivo examinations in Allium cepa and human cancer cells and systemically on mice tissues. Growing A. cepa roots and HCT-116 colorectal tumor cells were examined after HU and HU plus ascorbic acid exposure. DNA damage and antioxidant enzymatic activity were quantified in peripheral blood mononuclear cells (PBMC), bone marrow leukocytes and livers of mice after 7 day-HU treatment (7.5, 15 and 30 mg/kg/day) and Vitamin C 2 μM. Hydroxyurea presented toxic effects on meristematic Allium cepa cells, causing chromosomal abnormalities and reduction of mitotic index, killed HCT-116 colorectal carcinoma cells and induced DNA injuries upon mice cells (hepatocytes, bone marrow leukocytes and PBMC). Simultaneously, hydroxyurea decreased levels of CAT and GSH activities and expand lipid peroxidation. All these biochemical and physiological changes were ameliorated when associated with ascorbic acid, indicating it restored antioxidant enzymes, decreased MDA levels, removed peroxides and, consequently, presented cytoprotection against HU-provoked cellular damage in normal cells. On the other hand, antioxidants compounds may interfere on effectiveness of HU during anticancer chemotherapies.

Burden of vaso-occlusive crisis, its management and impact on quality of life of Indian sickle cell disease patients.

Sickle cell disease (SCD) with vaso-occlusive pain crisis (VOC) significantly impacts patient well-being and often results in extensive healthcare resource utilization. This study assessed the VOC burden, its management and its impact on patients' quality of life (QoL). A cross-sectional observational study was conducted between November 2021 and June 2022, including 1000 SCD patients from high-prevalence states in India. Data on demographics, clinical characteristics, VOC severity, management and QoL were collected. The study revealed that 33.5% of patients reported at least one VOC episode during the study period. In the year prior to their enrolment, 836 (83.60%) patients reported at least one VOC episode, with an equal proportion of 407/487 (83.6%) adults and 429/513 (83.6%) paediatric patients, reducing their QoL across all domains compared to patients without VOC. Of these, 469/1000 patients (46.9%) experienced ≥3 VOC episodes. Additionally, 764/1000 (76.40%) patients managed their VOCs at healthcare facilities, with 501/1000 (50.1%) requiring inpatient admissions. Further, 71.80% of patients received Hydroxyurea (HU) therapy. The study depicts the severity of the Arab-Indian haplotype in Indian SCD patients visiting healthcare settings based on high VOC burden. This highlights the urgent need for better management strategies and resource allocation for these patients.

Impact of Vitamin C and Hydroxyurea on the Reproductive System Health in Male Rats

Hydroxyurea (HU) is a medication used to treat various diseases and is also being studied for its effects on spermatogenesis. Vitamin C (VC), an antioxidant, has been shown to protect sperm cells from oxidative stress, potentially improving fertility and sperm quality. In a study involving twenty-four adult male albino rats divided into four groups, Group 1 served as the control, Group 2 received 5 mg of vitamin C, Group 3 received 100 mg of hydroxyurea per body weight, and Group 4 received a combination of vitamin C and hydroxyurea to assess essential functions of the reproductive system, including hormone levels, antioxidant markers, oxidative stress indicators, histopathology, and identification of DNA damage. The study found that hydroxyurea significantly reduced testicular weight, SOD, CAT, and GSH while increasing FSH and MDA levels and causing abnormalities in sperm morphology. Hydroxyurea also caused apparent alterations in the histological structure of the testes and comet parameters. Rats treated with vitamin C showed a significant increase in absolute and relative epididymis weight compared to the control group. Moreover, vitamin C intervention reversed the adverse effects observed in rats fed hydroxyurea, indicating that low doses of vitamin C can protect against testicular damage.

The Current Role of Hydroxyurea in the Treatment of Sickle Cell Anemia.

Despite advancements in treatment of sickle cell disease (SCD), hydroxyurea, a ribonucleotide reductase inhibitor, remains the cornerstone of therapy. While its primary effect is the elevation of fetal hemoglobin (HbF), hydroxyurea's mechanisms of action are multifaceted. Hydroxyurea (HU) reduces leukocyte and platelet counts, decreases the expression of endothelial adhesion molecules CD36 and CD49d, and increases nitric oxide and cyclic nucleotide levels, which may facilitate vascular dilation and further HbF induction. Numerous studies have demonstrated that hydroxyurea therapy reduces the frequency of painful episodes, acute chest syndrome, and the need for erythrocyte transfusions and hospitalizations. Long-term use of hydroxyurea leads to reduced morbidity and mortality. Hydroxyurea should be initiated in children from 9 months of age, including asymptomatic individuals, and is recommended for adults experiencing pain crises that significantly interfere with daily activities or quality of life, as well as those with severe or recurrent vaso-occlusive crises, ACS, or severe symptomatic anemia. Hydroxyurea is not recommended during pregnancy or lactation due to potential teratogenic effects and transfer into breast milk. However, its use may be considered in high-risk patients, particularly during the second and third trimesters. Concerns about secondary tumor development have not been substantiated in long-term follow-up studies. Alternative therapies, including L-glutamine, crizanlizumab, and voxelotor, are not presently approved or available for clinical use in Europe.

Prescribing Hydroxyurea in Sickle Cell Disease Patients: The Pattern and Association with Co-Prescribed Medications Used to Manage the Disease Complications.

Background and Objectives: Hydroxyurea (HU) is an effective medication used to reduce the frequency of painful crises associated with sickle cell disease (SCD). However, data describing its prevalence among SCD patients in the Eastern Region of Saudi Arabia are scarce. This is a multi-center, retrospective, cross-sectional study that aims to investigate the pattern of prescribing HU in SCD patients and to determine the association between prescribing HU and other co-prescribed medications used to manage SCD complications. Methods: Data were collected from patients who visited the hematology clinics of Al-Qatif Central Hospital (QCH) and King Fahad Hospital in Hofuf (KFHH) between June 2021 to May 2023. The data included demographics, prescribed medications, and recent laboratory test results, all of which were collected from patients' medical records. Descriptive statistics were utilized to assess the difference between HU users vs. non-users. A binary logistic regression model was used to determine the association between prescribing HU and co-prescribed medications used to manage SCD complications. The results are presented as the odds ratio (OR) and 95% confidence interval (95% CI). Results: This study included 2816 SCD patients with a 56% prevalence of HU prescription. HU was prescribed for young age groups more often compared to old age group patients. Young males were more likely to be prescribed with HU compared to females, and it becomes dominant in females after the age of 36. HU users were more likely to have paracetamol (69% vs. 53%, OR = 1.9, 95% CI 1.6-2.2), NSAIDs (50% vs. 35%, OR = 1.7, 95% CI 1.5-2), and opioids (41% vs. 37%, OR = 1.3, 95% CI 1.1-1.6) co-prescribed, and less often to have laxatives (8% vs. 5%, OR = 0.66, 95% CI 0.48-0.9) and anticoagulants (22% vs. 15%, OR = 0.56, 95% CI 0.46-0.68) co-prescribed compared to non-users. Conclusions: The pattern of prescribing HU, supported by the association findings, raises concerns about patients' compliance and adherence to HU therapy. Early health education, specifically to young female SCD patients, is warranted to increase the success rate of HU therapy.

Hydroxyurea Pharmacokinetic Evaluation in Patients with Sickle Cell Disease

Background: Hydroxyurea (HU), also known as hydroxycarbamide, is an oral ribonucleotide reductase inhibitor. In 1999, the United States Food and Drug Administration (FDA) approved HU for the treatment of sickle cell disease (SCD). Since then, it has become the cornerstone in the management of SCD patients, helping to reduce vaso-occlusive crises, acute chest syndrome, the need for blood transfusions, hospitalizations and mortality. There is considerable variability among individuals in HU pharmacokinetic (Pk) parameters that can influence treatment efficacy and toxicity. The objective of this work is part of a clinical study aimed at investigating HU Pk and determining the optimal sampling time to estimate the Area Under the Curve (AUC) in SCD patients. Methods: HU plasma concentration in 80 patients at various time points (2, 4, 6, 24 h) following a 48-h drug washout was quantified using High-Pressure Liquid Chromatography (HPLC) coupled with an ultraviolet (UV) detection method previously described in the literature and adapted to new conditions with partial modifications. Results: The mean HU administered dose was 19.5 ± 5.1 mg/kg (range: 7.7–37.5 mg/kg). The median AUC quantified in plasma patients was 101.3 mg/L/h (Interquartile Range (IQR): 72.5–355.9) and it was not influenced by the weight-based dose. However, there was a strong positive correlation between AUC and Body Mass Index (BMI) as well as dose per Body Surface Area (BSA). Along with a three-point approach for AUC determination present in the literature, we show results obtained from a four-point sampling strategy, which is more useful and effective for better optimizing dose escalation to the maximum tolerated dose (MTD). Moreover, we observed that most patients achieved the maximum HU plasma concentration two hours after drug administration, regardless of age differences. Conclusions: HU treatment, which represents a milestone in the treatment of SCD due to its ability to reduce disease complications and improve patients’ quality of life, requires careful monitoring to optimize the individual dose for saving potential side effects and/or adverse events.

Revised mechanism of hydroxyurea-induced cell cycle arrest and an improved alternative

Replication stress describes endogenous and exogenous challenges to DNA replication in the S-phase. Stress during this critical process causes helicase-polymerase decoupling at replication forks, triggering the S-phase checkpoint, which orchestrates global replication fork stalling and delayed entry into G2. The replication stressor most often used to induce the checkpoint response in yeast is hydroxyurea (HU), a clinically used chemotherapeutic. The primary mechanism of S-phase checkpoint activation by HU has thus far been considered to be a reduction of deoxynucleotide triphosphate synthesis by inhibition of ribonucleotide reductase (RNR), leading to helicase-polymerase decoupling and subsequent activation of the checkpoint, facilitated by the replisome-associated mediator Mrc1. In contrast, we observe that HU causes cell cycle arrest in budding yeast independent of both the Mrc1-mediated replication checkpoint response and the Psk1-Mrc1 oxidative signaling pathway. We demonstrate a direct relationship between HU incubation and reactive oxygen species (ROS) production in yeast and human cells and show that antioxidants restore growth of yeast in HU. We further observe that ROS strongly inhibits the in vitro polymerase activity of replicative polymerases (Pols), Pol α, Pol δ, and Pol ε, causing polymerase complex dissociation and subsequent loss of DNA substrate binding, likely through oxidation of their integral iron-sulfur (Fe-S) clusters. Finally, we present "RNR-deg," a genetically engineered alternative to HU in yeast with greatly increased specificity of RNR inhibition, allowing researchers to achieve fast, nontoxic, and more readily reversible checkpoint activation compared to HU, avoiding harmful ROS generation and associated downstream cellular effects that may confound interpretation of results.

Understanding the adsorption performance of hetero-nanocages (C12-B6N6, C12-Al6N6, and B6N6-Al6N6) towards hydroxyurea anticancer drug: a comprehensive study using DFT.

Cancer is a paramount health challenge to global health, which forms tumors that can invade nearby tissues and spread to neighboring cells. Recently, nanotechnology has been used to control the growth of cancer, in which anticancer drugs are delivered to cancerous cells via nanoparticles without damaging healthy tissues. In this study, DFT investigations were carried out to examine the adsorption behavior of C24, B12N12, and Al12N12 nanocages as well as their heterostructures C12-B6N6, C12-Al6N6, and B6N6-Al6N6 towards the hydroxyurea (HU) anticancer drug. In this regard, adsorption energy, interaction distance between the drug and nanocages, charge transfer, energy gap, dipole moment, quantum molecular descriptors, work function, and COSMO surface analysis were analyzed to understand their adsorption performance. Findings demonstrate that the adsorption energies of two hetero-nanocages on their hexagonal (SH) and tetragonal (ST) sites are favorable for the drug delivery process. The computed adsorption energy of B6N6-Al6N6 of the ST/AlN site is 183.59 kJ mol-1, which is higher than that of the C12-Al6N6 nanocage, including minimum adsorption distances. Negative adsorption energy with low adsorption distances implies an attractive interaction between the drug and nanocages. During the interaction, a significant amount of charge is transferred between the drug and nanocages. Furthermore, for both complexes, larger dipole moments were observed in water media compared to gas media. From DOS spectra, prominent peaks were found in the Fermi level after adsorption of HU on the nanocages, implying the reduction of the energy gap. Noticeable overlaps between the PDOS spectra of the nanocages and HU's close contact atom demonstrate the formation of chemical bonds between two specific atoms. Therefore, it can be concluded that among the nanocages, C12-Al6N6 and B6N6-Al6N6 may be suitable carriers for HU drug.

Hydroxyurea reduces the levels of the fetal globin gene repressors ZBTB7A/LRF and BCL11A in erythroid cells in vitro

Abstract Objectives Hydroxyurea (HU) is the most widely used therapy for adults and children with sickle cell disease (SCD). It is believed to act largely by inducing the transcription of fetal γ-globin genes to generate fetal hemoglobin (HbF), which inhibits the pathological polymerization of sickle hemoglobin (HbS). The mechanisms by which hydroxyurea elevates HbF are unclear. We explored the hypothesis that hydroxyurea induces HbF expression by inhibiting the expression of 2 γ-globin gene repressors, BCL11A and ZBTB7A (also known as LRF), which normally bind the γ-globin gene promoters to inhibit their expression after birth. Methods We treated immortalized murine erythroleukemia cells and normal human donor CD34+ hematopoietic stem and progenitor cell-derived erythroblasts with hydroxyurea and measured the effects on globin, BCL11A and ZBTB7A protein and mRNA expression. Results Treating murine erythroleukemia cells or human CD34+ hematopoietic stem and progenitor cell-derived erythroblasts with hydroxyurea reduced the protein levels of BCL11A and ZBTB7A compared to the vehicle-treated control. BCL11A mRNA levels were reduced in both cell types upon hydroxyurea treatment. However, ZBTB7A mRNA levels were only reduced in human CD34+ hematopoietic stem and progenitor cell-derived erythroblasts. Conclusions Hydroxyurea can act in erythroid cells to reduce the levels and activity of two direct fetal γ-globin transcriptional repressors with accompanying de-repression of the γ-globin genes and induction of HbF, which may explain the mechanism of action leading to amelioration of symptoms in SCD patients treated with this drug.

Lifespan Extension by Retrotransposons under Conditions of Mild Stress Requires Genes Involved in tRNA Modifications and Nucleotide Metabolism

Retrotransposons are mobile DNA elements that are more active with increasing age and exacerbate aging phenotypes in multiple species. We previously reported an unexpected extension of chronological lifespan in the yeast, Saccharomyces paradoxus, due to the presence of Ty1 retrotransposons when cells were aged under conditions of mild stress. In this study, we tested a subset of genes identified by RNA-seq to be differentially expressed in S. paradoxus strains with a high-copy number of Ty1 retrotransposons compared with a strain with no retrotransposons and additional candidate genes for their contribution to lifespan extension when cells were exposed to a moderate dose of hydroxyurea (HU). Deletion of ADE8, NCS2, or TRM9 prevented lifespan extension, while deletion of CDD1, HAC1, or IRE1 partially prevented lifespan extension. Genes overexpressed in high-copy Ty1 strains did not typically have Ty1 insertions in their promoter regions. We found that silencing genomic copies of Ty1 prevented lifespan extension, while expression of Ty1 from a high-copy plasmid extended lifespan in medium with HU or synthetic medium. These results indicate that cells adapt to expression of retrotransposons by changing gene expression in a manner that can better prepare them to remain healthy under mild stress.

Prognostic value of response to first-line hydroxyurea according to IPSET stratification in essential thrombocythemia.

Hydroxyurea (HU) constitutes the first-line treatment in most patients with essential thrombocythemia (ET), but criteria for changing therapy are not clearly established. The prognostic value of complete hematological response (CHR) and resistance/intolerance to HU was assessed in 1080 patients from the Spanish Registry of ET, classified according to revised IPSET-Thrombosis stratification (Very low- n = 61, Low- n = 83, Intermediate- n = 261, and High-risk n = 675). With a median therapy duration of 5 years, CHR was registered in 720 (67%) patients (1-year probability 51%) and resistance/intolerance in 219 (20%) patients (5-years probability 13%). After correction by other risk factors, High-risk patients achieving CHR showed a reduced risk of arterial thrombosis (HR: 0.35, 95%CI: 0.2-0.6, p = 0.001) and a trend towards lower risk of venous thrombosis (HR: 0.45, 95%CI: 0.2-1.02, p = 0.06) whereas no association was observed for intermediate- or low-risk patients. In comparison with non-responders, intermediate- and high-risk patients achieving CHR had longer survival and lower myelofibrosis incidence. Development of resistance/intolerance to HU, mainly cytopenia, was associated with higher probability of myelofibrosis but no effect on survival or thrombotic risk was demonstrated. In conclusion, CHR with HU is associated with better outcomes and might be an early indicator for selecting candidates to second-line clinical trials.

Strengths and limitations of the worm development and activity test (wDAT) as a chemical screening tool for developmental hazards

The worm Development and Activity Test (wDAT) measures C. elegans developmental milestone acquisition timing and stage-specific spontaneous locomotor activity (SLA). Previously, the wDAT identified developmental delays and SLA level changes in C. elegans with mammalian developmental toxicants arsenic, lead, and mercury. 5-fluorouracil (5FU), cyclophosphamide (CP), hydroxyurea (HU), and ribavirin (RV) are teratogens that also induce growth retardation in developing mammals. In at least some studies on each of these chemicals, fetal weight reductions were seen at mammalian exposures below those that had teratogenic effects, suggesting that screening for developmental delay in a small alternative whole-animal model could act as a general toxicity endpoint to identify chemicals for further testing for more specific adverse developmental outcomes. Consistent with mammalian developmental effects, 5FU, HU, and RV were associated with developmental delays with the wDAT. Exposures associated with developmental delay induced hypoactivity with 5FU and HU, but slight hyperactivity with RV. CP is a prodrug that requires bioactivation by cytochrome P450s for both therapeutic and toxic effects. CP tests as a false negative in several in vitro assays, and it was also a false negative with the wDAT. These results suggest that the wDAT has the potential to identify some developmental toxicants, and that a positive wDAT result with an unknown may warrant further testing in mammals. Further assessment with larger panels of positive and negative controls will help qualify the applicability and utility of this C. elegans wDAT assay within toxicity test batteries or weight of evidence approaches for developmental toxicity assessment.

The Effect of Resveratrol on Gamma Globin Gene Expression in Patients with Beta Thalassemia: The Role of Adaptation to Cellular Stress

HbF induction is an appropriate strategy to ameliorate the severity of β-thalassemia symptoms. Hydroxyurea (HU) is the most common chemical agent introduced as an HbF inducer but responsiveness to HU is variable and the introduction of HbF inducers alternative to HU with low cytotoxicity has been a crucial challenge. Resveratrol is an HbF inducer agent that may have favorable effects on the differentiation of hematopoietic erythroid progenitors (HEPs). The present study aimed to investigate the effect of resveratrol on γ-globin, stress response, and anti-apoptotic gene expression among hydroxyurea (HU)-responders and HU-nonresponders (HU-NR). Four cases of HU-R and four cases of HU-NR were studied. HEPs of the patients were cultured, and the expression of γ-globin, Foxo3, and Bclxl was assessed. Moreover, the differentiation and apoptotic rate of the cells were investigated using flow cytometry analysis. In three cases, the γ-globin gene expression increased after resveratrol treatment. All of the HU-NR patients were also non-responders to resveratrol (Res-NR). The expression of Foxo3 and Bclxl genes was higher in responders to resveratrol (Res-R) compared to non-responders (Res-NR). The rate of apoptosis in Res-R patients was also lower than in Res-NR. Responders to resveratrol also had a higher rate of HEP maturation. The cells of both HU–NR and Res-NR patients could not adapt to stress conditions and proceed to the erythroid differentiation. In conclusion, resveratrol increased the γ-globin expression in HEPs of β-thalassemia patients. The response was observed only in R-HU patients with similar cellular pathways.

Single-cell proteo-transcriptomic profiling reveals altered characteristics of stem and progenitor cells in patients receiving cytoreductive hydroxyurea in early-phase chronic myeloid leukemia.

Hydroxyurea (HU) is frequently used in the early phase of chronic myeloid leukemia (CML) to achieve cytoreduction prior to tyrosine kinase inhibitor (TKI) therapy. However, its impact on CML stem and progenitor cells (SPC) remains largely unknown. This study utilized targeted proteo-transcriptomic expression data on 596 genes and 51 surface proteins in 60,000 CD14-CD34+ cells from chronic phase CML patients to determine effects of shortterm HU treatment (4-19 days) on CML SPC. Peripheral blood and bone marrow samples were obtained from 17 CML patients eligible for short-term HU treatment (three patients before and after HU; seven patients before HU; and seven patients after HU) and subjected to single-cell CITE-seq and/or flow cytometry analysis. The analysis revealed enhanced frequencies of hemoglobin-expressing (HBA1, HBA2, HBB) erythroid progenitor cells in blood and bone marrow following HU treatment. In addition, there was an accumulation of cell subsets with S/G2/M phase-related gene and protein expression, likely representing cells arrested in, or progressing slowly through, the cell cycle. The increased frequency of cells in S/G2/M phase after HU was observed already among the most immature leukemic stem cells (LSC), and patients with a high fraction of LSC in the S/G2/M phase showed poor responsiveness to TKI treatment. We conclude that short-term HU treatment entails differentiation of erythroid progenitor cells and alters the characteristics of LSC in CML. The results imply that studies of LSC and progenitor populations in CML should take effects of initial HU therapy into account.

Hydroxyurea mobile directly observed therapy versus standard monitoring in patients with sickle cell anemia: a phase 2 randomized trial

BackgroundSickle cell anemia (SCA) prevalence remains high in sub-Saharan Africa. Long-term treatment with hydroxyurea (HU) increases survival, however, poor adherence to treatment could limit effectiveness. Whilst HU treatment adherence is currently high, this might decrease over time.MethodsWe conducted a single-center, randomized, open-label, parallel group phase 2 controlled clinical trial to determine whether mobile Directly Observed Therapy (m-DOT) increases HU treatment adherence (NCT02844673). Eligible participants were adults with homozygous SCA. People on a chronic blood transfusion program, with hemoglobin (Hb) A levels greater than 20% of the total Hb, total Hb less than 4 g/dL, pregnant or HIV positive were excluded. After a 3-month pre-treatment period participants were randomized to either m-DOT or standard monitoring arm. All participants received smart mobile phones and were treated with HU (15 mg/kg) daily for three months. In the m-DOT arm, drug intake was video recorded on cell phone by the participant and the video sent to the study team. The primary objective was to evaluate the effect of m-DOT on adherence to HU treatment by medication possession ratio (MPR).ResultsOf the 86 participants randomized, 76 completed the trial (26.13 ± 6.97 years, 63.5 % female). Adherence was high (MPR > 95 %) in both groups, 29 (80.6 %) in m-DOT versus 37 (94.9 %) in the standard monitoring arm (P = 0.079). No HU treatment was withheld from participants due to safety concerns.Conclusionsm-DOT did not increase adherence to HU treatment. We recommend that further testing in larger trials with a longer follow up period be undertaken.

Genome editing in K562 cells suggests a functional role for the XmnI Gg polymorphism: a widely used genetic marker in β-thalassemia and sickle cell disease patients.

The XmnI Gg -158 C/T polymorphism has been widely associated with fetal hemoglobin (HbF) levels, the severity of disease, and the response to the drug hydroxyurea (HU) in both β-thalassemia (β-thal) and sickle cell disease (SCD) patients. However, the functional significance of this single nucleotide polymorphism (SNP) remains unclear. To gain insight, green fluorescence protein (GFP) cassettes harboring the XmnI C or T alleles in their left homology arms (i.e. Gg promoters) were knocked into the Gg gene(s) of K562 cells via CRISPR/Cas9. Subsequently, the GFP fluorescence levels were compared in the ensuing cell populations and isolated clones. In both instances, median fluorescence intensities (MFI) of the knockin cells having the inserted XmnI T allele were higher than those having the XmnI C allele. Our results suggest that the XmnI T allele can increase Gg expression in K562 cells. The possible functional significance of the XmnI Gg -158 C/T polymorphism provides a rationale for the aforementioned associations. Furthermore, the XmnI polymorphism as a functional SNP substantiates its importance as a prognostic marker.

Enhancing the sensing performance of Al-modified graphene+ based sensor for anticancer medicinal molecules: A DFT study

It is recently reported that a new pure carbon-based structure graphene+ (G+) exhibits more excellent properties such as buckling structure similar to penta-graphene and Dirac cones like graphene. In this work, a comprehensive exploration and comparison of the adsorption behaviors and sensing performances of optimal Al-doped G+ (Al_G+) and pristine G+ are explored by combing density functional theory with non-equilibrium Green’s function for anticancer drugs molecules, namely Cisplatin (CP), Hydroxyurea (HU), 5-fluorouracil (5-FU) and 6-Mercaptopurine (6-MP). Firstly, the stable and optimal structure of Al_G+ is obtained by sequentially substituting three distinct carbon atoms with Al atom. Moreover, it is found that the introduction of Al atom leads to the disappearance of the Dirac cones, resulting in a transition from semi-metallic to metallic. Subsequently, CP and HU exhibit physical adsorption, 5-FU and 6-MP are chemically adsorbed on the surface of G+ by high adsorption energy. However, the adsorption energy of Al_G+ for both CP and HU all increased by about 1.5 eV compared with G+. 5-FU and 6-MP are chemically adsorbed on Al_G+ by appropriate adsorption energies. Finally, the G+/Al_G+-based sensor is constructed to investigate the sensitivity of medicinal molecules according to chemisorption. It is seen that the sensitivity of the G+ to 5-FU and 6-MP is all less than 22 %. Although the Al_G+ has the sensitivity below 22 % for CP, HU and 5-FU, which has up to 62 % for 6-MP, more than 40 % higher than other medicinal molecules. Further, the high sensitivity and selectivity of Al_G+ towards 6-MP are elucidated through scattering states and transmission spectra of sensors. Upon the results, it suggests that Al_G+ has broad application prospects in multiple fields such as drug delivery and medicinal molecular detection especially for 6-MP.

Impact of hydroxyurea on follicle density in patients with sickle cell disease

AbstractThe impact of hydroxyurea (HU) on the ovarian reserve of female patients with sickle cell disease (SCD) remains poorly elucidated. Only direct histological analysis of ovarian follicle density can effectively evaluate HU’s effect on ovarian reserve. By analyzing digitized slides of ovarian tissue from girls and young women with SCD who underwent ovarian tissue cryopreservation (OTC) before hematological stem cell transplantation, we meticulously counted follicles and categorized them based on their growth stage. We then calculated the densities of different follicle types and assessed their correlation with patient characteristics, clinical manifestations, and treatments extracted from medical records. Seventy-six patients with SCD participated in the study, with a median age at OTC of 10.2 years (interquartile range [IQR], 7.5-14.6), and 50 (65.8%) were prepubertal. Of these, 35 patients (46.1%) had received HU, with a median daily dosage of 23.0 mg/kg (IQR, 20.0-25.0) and median exposure time of 44 months (IQR, 24.0-54.0). Primordial follicle density was comparable between the HU and non-HU groups (5.8 follicles per mm2 [IQR, 1.0-13.3] vs 4.2 follicles per mm2 [IQR, 1.1-14.4], respectively; P = .95). However, in the HU group, after adjusting for age, the density of growing follicles was marginally lower than that in the non-HU group (P = .09). Notably, other parameters such as vaso-occlusive crisis did not affect follicular density. In conclusion, exposure to HU did not demonstrate a reduction in ovarian reserve in girls or women with SCD. Therefore, fertility preservation measures before initiating HU treatment do not seem necessary.

Towards genomic medicine: a tailored next-generation sequencing panel for hydroxyurea pharmacogenomics in Tanzania

BackgroundPharmacogenomics of hydroxyurea is an important aspect in the management of sickle cell disease (SCD), especially in the era of genomic medicine. Genetic variations in loci associated with HbF induction and drug metabolism are prime targets for hydroxyurea (HU) pharmacogenomics, as these can significantly impact the therapeutic efficacy and safety of HU in SCD patients.MethodsThis study involved designing of a custom panel targeting BCL11A, ARG2, HBB, HBG1, WAC, HBG2, HAO2, MYB, SAR1A, KLF10, CYP2C9, CYP2E1 and NOS1 as potential HU pharmacogenomics targets. These genes were selected based on their known roles in HbF induction and HU metabolism. The panel was designed using the Illumina Design Studio (Illumina, San Diego, CA, USA) and achieved a total coverage of 96% of all genomic targets over a span of 51.6 kilobases (kb). This custom panel was then sequenced using the Illumina MiSeq platform to ensure high coverage and accuracy.ResultsWe are reporting a successfully designed Illumina (MiSeq) HU pharmacogenomics custom panel encompassing 51.6 kilobases. The designed panel achieved greater than 1000x amplicon coverage which is sufficient for genomic analysis.ConclusionsThis study provides a valuable tool for research in HU pharmacogenomics, especially in Africa where SCD is highly prevalent, and personalized medicine approaches are crucial for improving patient outcomes. The custom-designed Illumina (MiSeq) panel, with its extensive coverage and high sequencing depth, provides a robust platform for studying genetic variations associated with HU response. This panel can contribute to the development of tailored therapeutic strategies, ultimately enhancing the management of SCD through more effective and safer use of hydroxyurea.