Human Leukemia Research Articles

METTL3-mediated TIM1 promotes macrophage M1 polarization and inflammation through IGF2BP2-dependent manner.

Macrophage polarization and inflammation may play an important role in the development of sepsis. T-cell immunoglobulin mucin 1 (TIM1) has been demonstrated to promote macrophage inflammatory responses. However, whether TIM1 regulates macrophage polarization and inflammation to affect sepsis development remains unclear. Human monocytic leukemia cell line was induced into macrophages, followed by stimulated with LPS and IL-4 to induce M1 polarization and M2 polarization. The expression levels of TIM1, methyltransferase 3 (METTL3), and insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) were examined by qRT-PCR and western blot. IL-6, IL-1β, and TNF-α levels were tested by ELISA. CD86+cell rate was analyzed by flow cytometry. The m6A methylation level of TIM1 was assessed by MeRIP assay. The interaction of between TIM1 and METTL3 or IGF2BP2 was assessed by dual-luciferase reporter assay and RIP assay. TIM1 knockdown repressed LPS-induced macrophage M1 polarization and inflammation. In terms of mechanism, METTL3 promoted TIM1 expression through m6A modification, and this modification could be recognized by IGF2BP2. Besides, knockdown of METTL3/IGF2BP2 suppressed LPS-induced macrophage M1 polarization and inflammation, while this effect could be eliminated by TIM1 overexpression. METTL3/IGF2BP2/TIM1 axis promoted macrophage M1 polarization and inflammation, which might provide potential target for sepsis treatment.

Phenolic Bisabolane Sesquiterpene Derivatives from an Arctic Marine-derived Fungus Aspergillus sydowii MNP-2

Background:: Filamentous fungi in the genus Aspergillus are well known for their important roles in production of bioactive secondary metabolites with diversely chemical structures and potential application in pharmaceutical industry. Objective:: The present study aimed to investigate the phenolic bisabolane sesquiterpene (PBS) derivatives from an Arctic marine-derived fungus Aspergillus sydowii MNP-2. Methods:: In this study, antimicrobial activities were carried out according to the broth microdilution assay, nitric oxide (NO) production in mouse macrophages (RAW264.7) and BV2 microglial cells was used to detect the inhibitory effect of compounds in inflammatory reactions, and in vitro inhibitory cell proliferation activity was determined by the cell counting kit-8 (CCK-8) assay. Results:: In this work, chemical investigation of an Arctic marine-derived strain A. sydowii MNP-2 led to the isolation of 11 PBSs (1-11) using various chromatographic methods. Their chemical structures were unambiguously determined by 1H NMR spectroscopy and mass spectrometry analyses as well as comparison with literature data. It is noteworthy that compounds 1, 7 and 11 were firstly obtained from A. sydowii. Antimicrobial assay showed that these chemicals had no potent inhibitory effect on Staphylococcus aureus, Escherichia coli, and Candida albicans with MIC values > 16 μg/mL. Additionally, the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)- induced inflammation in mouse macrophages (RAW264.7) and BV2 microglial cells were all below 10% for compounds 4-6 and 8, indicating almost negligible anti-inflammatory efficacy. Among the tested compounds 4-6 and 8 for tumor-cell proliferation inhibition activities, compound 5 demonstrated the strongest inhibitory effect against human acute promyelocytic leukemia cells (HL-6) with a 44.76% inhibition rate. Conclusion:: In the present study, 11 PBS derivatives were purified and characterized from the solidand liquid-state fermentations of the Arctic marine-derived fungus A. sydowii MNP-2. Unfortunately, none of these metabolites had significant antimicrobial, anti-inflammatory, or tumor-cell proliferation inhibition activities.

HTLV-1/2 infection in Italy: a narrative review of epidemiological studies.

The human T-cell leukemia virus type 1 (HTLV-1) was first described in 1980. It is spread in highly endemic regions in the world, such as the Southwestern part of Japan, sub-Saharan Africa and South America, Caribbean, Middle East, and Australo-Melanesia regions. HTLV-1 causes adult T cell leukemia and is associated with many inflammatory conditions, most notably HTLV-1-associated myelopathy/tropic spastic paraparesis. HTLV-2, first isolated in 1982, was recognized as a common infection in intravenous drug users, but a clear association with disease remains elusive. The first estimate of HTLV-1-positive individuals worldwide, in 1993, was around 10-20 millions. Due to the lack of global population-based prevalence studies, this is considered an underestimate at the moment. Furthermore, HTLV-1 prevalence in Europe is impacted by changing migration flows. Particularly, no data on HTLV-1 prevalence in the general population in Italy are available. Here, we report a systematic literature review of studies conducted in Italy on HTLV-1/2 from 1980 to 2023. Based on the criteria we adopted a total of 426 publications were found (64 reviews, 99 epidemiological, and 263 translational studies). The contents of some representative publications are summarized and discussed. Moreover, an approximate estimation of about 26,000 HTLV-1 positive foreigners living in Italy was obtained from updated data of foreigners from each single country officially registered as resident in Italy and from data on HTLV-1 prevalence among the general population in the corresponding countries.

Long-Term Survival of Patients with Adult T-Cell Leukemia/Lymphoma Treated with Amplified Natural Killer Cell Therapy

Background: Adult T-cell leukemia/lymphoma (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1) after a long latent infection. HTLV-1 induces the indolent or aggressive type of leukemia in 5% of HTLV-1 carriers. ATL, especially the aggressive type, is resistant to multi-agent chemotherapy. The indolent type often progresses to the aggressive type. Even in the most indolent-type cases, that is, smoldering ATL, the average survival time is 55.0 months. Case Presentation: Five patients with ATL were followed up for their clinical course after amplified natural killer cell (ANK) therapy. Four patients who received ANK therapy as first-line therapy achieved complete remission and showed long-term survival without aggressive conversion or relapse for more than 5 years. One patient was treated with multiagent chemotherapy due to acute exacerbation but relapsed 2 months later. She was subsequently treated with radiation and ANK therapy and survived for more than 6 years. Furthermore, ANK therapy enhanced the immune function of ATL patients to a level higher than that of normal individuals. Conclusions: ANK therapy has great potential as first-line treatment for ATL.

RETRACTION: Antisense inhibition of Bcr-Abl/c-Abl synthesis promotes telomerase activity and upregulates tankyrase in human leukemia cells.

R. Bakalova, H. Ohba, Z. Zhelev, T. Kubo, M. Fujii, M. Ishikawa, Y. Shinohara, and Y. Baba, 'Antisense inhibition of Bcr-Abl/c-Abl synthesis promotes telomerase activity and upregulates tankyrase in human leukemia cells,' FEBS Letters 564, no. 1-2 (2004): 73-84, https://doi.org/10.1016/S0014-5793(04)00318-7. The above article, published online on 9 April 2004 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors; the journal Editor-in-Chief, Michael Brunner; FEBS Press; the National Institute of Advanced Industrial Science and Technology (AIST); and John Wiley and Sons Ltd. Following publication, concerns were raised by a third-party regarding several figures in the article. The subsequent institutional investigation conducted by the AIST revealed: Inappropriate duplication of image panels within the article, between the β-actin loading controls for 4 and 6 days in the Western blot of Fig. 2A K-562; between the subpanels of the electrophoresis blots in Fig. 4A K-562 and Jurkat cells; and between the subpanels of the electrophoresis blots in Fig. 6B. Band insertion in the Western blot of Fig. 6A p210 Bcr-Ab lane. Inappropriate duplication of images between this article (Fig. 2A K562 β-actin and Fig. 4B K562 6 days treatment bands) and an earlier publication from 2003 by an overlapping group of authors representing different experimental conditions. Inappropriate duplication and modification of an image between this article (Figure 3A2) and an earlier publication from 2004 by an overlapping group of authors representing different experimental conditions. Therefore, the conclusions of the paper are substantially compromised and the institute has recommended the paper to be retracted. The editors of the journal agree with the retraction based on the institutional investigation.

Pharmacological restriction of genomic binding sites redirects PU.1 pioneer transcription factor activity.

Transcription factor (TF) DNA-binding dynamics govern cell fate and identity. However, our ability to pharmacologically control TF localization is limited. Here we leverage chemically driven binding site restriction leading to robust and DNA-sequence-specific redistribution of PU.1, a pioneer TF pertinent to many hematopoietic malignancies. Through an innovative technique, 'CLICK-on-CUT&Tag', we characterize the hierarchy of de novo PU.1 motifs, predicting occupancy in the PU.1 cistrome under binding site restriction. Temporal and single-molecule studies of binding site restriction uncover the pioneering dynamics of native PU.1 and identify the paradoxical activation of an alternate target gene set driven by PU.1 localization to second-tier binding sites. These transcriptional changes were corroborated by genetic blockade and site-specific reporter assays. Binding site restriction and subsequent PU.1 network rewiring causes primary human leukemia cells to differentiate. In summary, pharmacologically induced TF redistribution can be harnessed to govern TF localization, actuate alternate gene networks and direct cell fate.

Novel alloxazine analogues: design, synthesis, and antitumour efficacy enhanced by kinase screening, molecular docking, and ADME studies

This study describes the development of novel alloxazine analogues as potent antitumor agents with enhanced selectivity for tumour cells. Twenty-nine out of 45 newly compounds were investigated in vitro for their growth inhibitory activities, against two human tumour cell lines, namely, the human T-cell acute lymphoblastoid leukaemia cell line (CCRF-HSB-2) and human oral epidermoid carcinoma cell line (KB), and the antitumor agent “Ara-C” was used as a positive reference in this investigation. Compounds 9e and 10J were the highest among their analogues, against both tumour cell lines (CCRF-HSB-2 and KB). Correlation analyses demonstrated a strong relationship between the IC50 values and AutoDock binding free energy or calculated inhibition (Ki ). The study delves into structure–activity relationships (SARs) through advanced modelling tools integrated with structure-based drug design (SBDD) using GOLD 5.2.2, AutoDock 4.2, and Accelrys Discovery Studio 3.5. Physicochemical properties, pharmacokinetics, drug-likeness, and toxicity predictions of the most potent alloxazine derivatives were conducted using ProTox-II and Swiss ADME for effective antitumor agents with improved selectivity.

Peculiar transcriptional reprogramming with functional impairment of dendritic cells upon exposure to transformed HTLV-1-infected cells.

Manipulation of immune cell functions, independently of direct infection of these cells, emerges as a key process in viral pathophysiology. Chronic infection by Human T-cell Leukemia Virus type 1 (HTLV-1) is associated with immune dysfunctions, including misdirected responses of dendritic cells (DCs). Here, we interrogate the ability of transformed HTLV-1-infected T cells to manipulate human DC functions. We show that exposure to transformed HTLV-1-infected T cells induces a biased and peculiar transcriptional signature in monocyte-derived DCs, associated with an inefficient maturation and a poor responsiveness to subsequent stimulation by a TLR4 agonist. This poor responsiveness is also associated with a unique transcriptional landscape characterized by a set of genes whose expression is either conferred, impaired or abolished by HTLV-1 pre-exposure. Induction of this functional impairment requires several hours of coculture with transformed HTLV-1-infected cells, and associated mechanisms driven by viral capture, cell-cell contacts, and soluble mediators. Altogether, this cross-talk between infected T cells and DCs illustrate how HTLV-1 might co-opt communications between cells to induce a unique local tolerogenic immune microenvironment suitable for its own persistence.

Phytochemical profiling and characterization of flavonoid derivatives from propolis sample and investigation of cytotoxic and antiprotozoal activities

Recently, the growth of consumer demand for functional foods with potential nutritional and health benefits led to rapid growth of analytical tools for profiling of bioactive metabolites and assure quality. Bee propolis is one of the most important bee products owing to its myriad health value. As a gummy exudate produced in beehives after harvesting from different plant species, bee propolis contains bioactive secondary metabolites. The current study aims to profiling the chemical composition of propolis samples from Nigeria using HPLC–UV-ELSD and with the aid of NMR-based analysis for assignment of metabolites classes abundant in Nigerian propolis. Red Nigerian propolis samples were subjected to phytochemical analysis using HPLC–UV-ELSD and NMR. Further chromatographic separation of promising fractions was performed by column chromatography and size exclusion chromatography. Screening of the antitrypanosomal and cytotoxic activities against Trypanosoma brucei and human leukemia cell lines (U937), respectively, was performed. The performance of LC–MS permitted identification of the different components from which 13 compound were identified and allowed combination of fractions to afford 9 fractions from which two isoflavonoids were isolated and identified using 1D and 2D NMR analysis with MS as isosativan and Medicarpin. Red Nigerian propolis crude extract showed the highest inhibitory activity at 6.5 µg/ml compared to moderate activity for the isolated compounds with MIC of 7.6 µg/ml and 12.1 µg/ml for medicarpin and isosativan, respectively. Moreover, the fraction RN-6 from the total extract showed the potent cytotoxic effect with IC50 = 26.5 µg/ml compared to standard diminazen which showed IC50 = 29.5 µg/ml.

JR-AB2-011 induces fast metabolic changes independent of mTOR complex 2 inhibition in human leukemia cells.

The mechanistic target of rapamycin (mTOR) is a crucial regulator of cell metabolic activity. It forms part of several distinct protein complexes, particularly mTORC1 and mTORC2. The lack of specific inhibitors still hampers the attribution of mTOR functions to these complexes. JR-AB2-011 has been reported as a specific mTORC2 inhibitor preventing mTOR binding to RICTOR, a unique component of mTORC2. We aimed to describe the effects of JR-AB2-011 in leukemia/lymphoma cells, where the mTOR pathway is often aberrantly activated. The impact of JR-AB2-011 on leukemia/lymphoma cell metabolism was analyzed using the Seahorse platform. AKT phosphorylation at Ser473 was used as a marker of mTORC2 activity. mTOR binding to RICTOR was assessed by co-immunoprecipitation. RICTOR-null cells were derived from the Karpas-299 cell line using CRISPR/Cas9 gene editing. In leukemia/lymphoma cell lines, JR-AB2-011 induced a rapid drop in the cell respiration rate, which was variably compensated by an increased glycolytic rate. In contrast, an increase in the respiration rate due to JR-AB2-011 treatment was observed in primary leukemia cells. Unexpectedly, JR-AB2-011 did not affect AKT Ser473 phosphorylation. In addition, mTOR did not dissociate from RICTOR in cells treated with JR-AB2-011 under the experimental conditions used in this study. The effect of JR-AB2-011 on cell respiration was retained in RICTOR-null cells. JR-AB2-011 affects leukemia/lymphoma cell metabolism via a mechanism independent of mTORC2.

The Oncoprotein Fra-2 Drives the Activation of Human Endogenous Retrovirus Env Expression in Adult T-Cell Leukemia/Lymphoma (ATLL) Patients

Human endogenous retroviruses (HERVs) are retroviral sequences integrated into 8% of the human genome resulting from ancient exogenous retroviral infections. Unlike endogenous retroviruses of other mammalian species, HERVs are mostly replication and retro-transposition defective, and their transcription is strictly regulated by epigenetic mechanisms in normal cells. A significant addition to the growing body of research reveals that HERVs’ aberrant activation is often associated with offsetting diseases like autoimmunity, neurodegenerative diseases, cancers, and chemoresistance. Adult T-cell leukemia/lymphoma (ATLL) is a very aggressive and chemoresistant leukemia caused by the human T-cell leukemia virus type 1 (HTLV-1). The prognosis of ATLL remains poor despite several new agents being approved in the last few years. In the present study, we compare the expression of HERV genes in CD8+-depleted PBMCs from HTLV-1 asymptomatic carriers and patients with acute ATLL. Herein, we show that HERVs are highly upregulated in acute ATLL. Our results further demonstrate that the oncoprotein Fra-2 binds the LTR region and activates the transcription of several HERV families, including HERV-H and HERV-K families. This raises the exciting possibility that upregulated HERV expression could be a key factor in ATLL development and the observed chemoresistance, potentially leading to new therapeutic strategies and significantly impacting the field of oncology and virology.

Monitoring Apoptosis and Myeloid Differentiation of Acridine Orange-Mediated Sonodynamic Therapy-Induced Human Promyelocytic Leukemia HL60 Cells.

In the treatment of acute myeloid leukemia (AML), conventional therapies can lead to severe side effects and drug resistance. There is a need for alternative treatments that do not cause treatment resistance and have minimal or no side effects. Sonodynamic therapy (SDT), due to its noninvasive, multiple repeatability, localized treatment feature and do not cause treatment resistance, emerges as an alternative treatment option. However, it has not received sufficient attention in the treatment of AML especially acute promyelocytic leukemia (APL). The aim of the study was to investigate the potential differentiation and antileukemic effects of acridine orange (AO)-mediated SDT on HL60 cells. Cell viability was determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT)method in the control, ultrasound, AO concentrations, and ultrasound-exposed AO concentrations groups. Transmission electron microscopy (TEM) was used to determine morphology, and flow cytometry was used to determine apoptosis, DNA cycle, cell volume, mitochondria membrane potential (Δψm), reactive oxygen species (ROS) production, and differentiation markers (CD11b and CD15) expressions. Additionally, toluidine blue staining for semithin sections was used to determine differentiation. The cytotoxicity of AO-mediated SDT on HL60 cells was significantly higher than other groups, and TEM images showed that it caused various morphological changes typical for apoptosis. Flow cytometry results showed the presence of early apoptosis, subG1 arrest, loss of Δψm, increase of intracellular ROS production, decreased cell volume, and increased expression of CD11b (1.3-fold) antigen and CD15 (1.2-fold) antigen. Data showed that AO-mediated SDT significantly induced apoptosis in HL60 cells. Increased expression of CD11b and CD15 antigens and morphological findings demonstrated that AO-mediated SDT contributes to granulocytic differentiation in HL60 cells. AO-mediated SDT has potential as an alternative treatment of APL.

Minimal Requirements for Cancer Initiation: A Comparative Consideration of Three Prototypes of Human Leukemia.

Even if its completed form is complex, cancer originates from one or two events that happened to a single cell. A simplified model can play a role in understanding how cancer initiates at the beginning. The pathophysiology of leukemia has been studied in the most detailed manner among all human cancers. In this review, based on milestone papers and the latest research developments in hematology, acute promyelocytic leukemia (APL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML) with RUNX1-RUNX1T1 are selected to consider minimal requirements for cancer initiation. A one-hit model can be applied to the initiation of APL and CML whereas a two-hit model is more suitable to the initiation of AML with RUNX1-RUNX1T1 and other AMLs. Even in cancer cells with multiple genetic abnormalities, there must be a few mutant genes critical for the mutant clone to survive and proliferate. Such genes should be identified and characterized in each case in order to develop individualized target therapy.

Synthesis, molecular docking, dynamics study and preliminary cytotoxicity study of some coumarin linked imidazothiadiazoles

A new series of coumarin-linked imidazo[2,1-b][1,3,4]thiadiazoles were synthesized and evaluated for their cytotoxicity inhuman T-lymphocyte (CEM), human cervix carcinoma (HeLa) and murine leukemia cells (L1210). Among the tested compounds, 3-[5‑bromo-2-(thiophen-2-ylmethyl)imidazo[2,1-b][1,3,4]thiadiazol-6-yl]-2H-chromen-2-one 9b exhibited cytotoxicity at 0.77 μM against CEM, 1.6 μM against L1210 and 0.38 μM against HeLa cells. Compound 6-(2-oxo-2H-chromen-3-yl)-2-(thiophen-2-ylmethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-carbaldehyde 10b showed cytotoxicity at 3.5 μM against CEM and at 9.5 μM against HeLa cells. Further, molecular docking simulations performed to evaluate the possibility of these synthesized analogs as inhibitors of heat shock protein 90 (Hsp90), Pdb ID: 1UYL revealing that docking predictions are in good agreement with in-vitro results (-10.7 for 9b and -10.5 for 10b). The in-silico ADME parameters, pharmacokinetics and drug-likeness of all derivatives were examined in detail using the Swiss ADME webserver. By applying molecular dynamics simulation experiments a better stability was observed of compounds 8b, 9a, 10b and 11b.

The Ubiquitin-Conjugating Enzyme E2 O (UBE2O) and Its Therapeutic Potential in Human Leukemias and Solid Tumors.

Protein degradation is a biological phenomenon essential for cellular homeostasis and survival. Selective protein degradation is performed by the ubiquitination system which selectively targets proteins that need to be eliminated and leads them to proteasome degradation. In this narrative review, we focus on the ubiquitin-conjugating enzyme E2 O (UBE2O) and highlight the role of UBE2O in many biological and physiological processes. We further discuss UBE2O's implications in various human diseases, particularly in leukemias and solid cancers. Ultimately, our review aims to highlight the potential role of UBE2O as a therapeutic target and offers new perspectives for developing targeted treatments for human cancers.

Ultrasound-assisted extraction of withanolides from Tubocapsicum anomalum: Process optimization, isolation and identification, and antiproliferative activity

Tubocapsicum anomalum, a Chinese medicinal plant rich in anti-tumor withanolides, requires efficient extraction methods. In this paper, an HPLC method was first established for the detection of withanolides, and gradient elution was carried out using a methanol–water solvent system. It was found that the content of withanolides was the highest in the leaves of T. anomalum, followed by the stems and fruits, and almost none in the roots. During the actual picking process, the quantity of leaves collected was relatively small, while the number of stems was the highest. Therefore, the Box-Behnken response surface method was used to optimize the ultrasonic-assisted extraction process of withanolides from the stems of T. anomalum. The optimal extraction conditions were determined as follows: the liquid–solid ratio was 20:1, the extraction solvent was 70 % ethanol, the ultrasonic power was 250 W, the ultrasonic time was 40 min, and the ultrasonic temperature was 50 °C. Under these conditions, the average yields of tubocapsenolide A (Te-A) and tubocapsanolide A (Ta-A) can reach 2.87 ± 0.12 mg/g and 1.18 ± 0.05 mg/g, respectively. We further compared extraction rates of two withanolides from different parts of T. anomalum using ultrasonic and traditional extraction methods. Ultrasonic extraction significantly increased rates, with the highest yields from leaves, followed by stems and fruits. The results show that ultrasonic optimization can improve extraction rate, reduce time, lower costs, enhance quality, and increase yield. Therefore, the optimized ultrasonic-assisted extraction process was adopted to extract the aerial parts of T. anomalum and separate the components. After optimization, the extract underwent several chromatographic separations to isolate eight previously undescribed withanolides (1–8) and two artificial withanolides (9–10), in addition to fifteen known compounds (11–25). Their structures were established through extensive spectroscopic data analysis. The compounds were evaluated for their antiproliferative effects against multiple cancer cell lines, including human hepatocellular carcinoma cells (HepG2, Hep3B, and MHCC97-H), human lung cancer cells (A549), human fibro-sarcoma cancer cells (HT1080), human chronic myeloid leukemia cells (K562), and human breast cancer cells (MDA-MB-231 and MCF7). Compounds 1–3, 5, 7, 11, 13, 15–16, and 22 displayed significant activity with IC50 values of 5.14–19.87 μM. The above results indicate that ultrasonic-assisted extraction technology can be used to obtain new withanolides more efficiently from T. anomalum, thereby enhancing the utilization rate of T. anomalum resources.

Plasma vitamin D levels are correlated with the pathogenesis of human T-cell leukemia virus type 1-associated diseases.

The active form of vitamin D (VD) exerts hormonal effects by regulating the expression of genes involved in T-cell activity, cell differentiation, and proliferation. Human T-cell leukemia virus type 1 (HTLV-1) is a causative agent of life-threatening diseases, adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy (HAM). Among ATL patients, hypercalcemia is one of the most serious complications due to bone resorption. In this study, wild-type mice administered UV-irradiated HTLV-1-infected cells showed up to 47% decrease of plasma VD level compared with untreated mice. To clarify the effect of HTLV-1 on plasma VD level, 315 samples registered in nationwide cohort study on ATL onset were measured. The VD level in HAM (14.98 ± 8.5 ng/mL) was significantly lower than those in asymptomatic carriers and ATL (p < 0.05). Upon comparing the VD levels in ATL stratified by disease subtypes, acute ATL showed a lower level (15.81 ± 12.0 ng/mL) than chronic and smoldering types (p < 0.05). In the longitudinal observation, VD levels were significantly higher in untreated spontaneous remission cases than in ATL progression cases, in which the VD levels decreased approximately 40% after onset. In cases of relapse after transplantation, the plasma VD level dropped to 38.7% of the pre-relapse level, while in cases of complete remission, the VD level increased with improvement of the performance status. Taken together, these results suggest that plasma VD level is a potential indicator for the onset and relapse of HTLV-1-associated diseases.

Management of Refractory/Resistant Herpes Simplex Virus Infections in Haematopoietic Stem Cell Transplantation Recipients: A Literature Review.

Herpes simplex virus (HSV) infections in allogeneic haematopoietic stem cell transplantation (HSCT) recipients pose significant challenges, with higher incidence, severity, and risk of emergence of resistance to antivirals due to impaired T-cell mediated immunity. This literature review focuses on acyclovir-refractory/resistant HSV infections in HSCT recipients. The review addresses the efficacy of antiviral prophylaxis, the incidence of acyclovir-refractory/resistant HSV infections, and the identification of risk factors and potential prognostic impact associated with those infections. Additionally, alternative therapeutic options are discussed. While acyclovir prophylaxis demonstrates a significant benefit in reducing HSV infections in HSCT recipients and, in some cases, overall mortality, concerns arise about the emergence of drug-resistant HSV strains. Our systematic review reports a median incidence of acyclovir-resistant HSV infections of 16.1%, with an increasing trend in recent years. Despite limitations in available studies, potential risk factors of emergence of HSV resistance to acyclovir include human leucocyte antigen (HLA) mismatches, myeloid neoplasms and acute leukaemias, and graft-versus-host disease (GVHD). Limited evidences suggest a potentially poorer prognosis for allogeneic HSCT recipients with acyclovir-refractory/resistant HSV infection. Alternative therapeutic approaches, such as foscarnet, cidofovir, topical cidofovir, optimised acyclovir dosing, and helicase-primase inhibitors offer promising options but require further investigations. Overall, larger studies are needed to refine preventive and therapeutic strategies for acyclovir-refractory/resistant HSV infections in allogeneic HSCT recipients and to identify those at higher risk.

CYTOTOXICITY OF ALOE VERA EXTRACT ON CHRONIC MYELOID LEUKEMIA CELLS; IN VITRO STUDY ON CYTOTOXICITY ON HL-60 CELLS

Aloe vera has been traditionally used for its various therapeutic properties, but its potential anticancer effects have not been thoroughly explored. Understanding its efficacy against leukemia could significantly impact care recommendations for leukemia patients. Objective: This in-vitro study aims to establish the anti-cancerous effects of Aloe vera on the Human Leukemia HL-60 cell line. Methods: Following approval from the Ethical Review Committee, this study involved culturing the HL-60 cell line and treating it with increasing concentrations of Aloe vera extract to determine the half-maximal inhibitory concentration (IC50). The MTT assay was employed to assess cell viability, and the absorbance was measured using an ELISA reader. Gene expression levels of pro-apoptotic biomarkers, Caspase-3 and Caspase-9, were also quantified to gauge apoptosis induction. Results: Aloe vera demonstrated a relatively low IC50 value of 13.1 µM in the HL-60 cell line, indicating potent cytotoxicity. Notably, pro-apoptotic biomarkers were highly expressed, with Caspase-3 and Caspase-9 recording gene expression levels of 11.1 and 13.7, respectively. Conclusion: Aloe vera exhibited significant pro-apoptotic effects against the leukemia HL-60 cell line, suggesting its potential as an anti-cancer agent. Further in-vivo and clinical studies are warranted to elucidate the specific pathways through which Aloe vera exerts these effects and to validate its use in clinical settings.

The pro-differentiating capability of a flavonoid-rich extract of Citrus bergamia juice prompts autophagic death in THP-1 cells

Acute myeloid leukemia (AML) is a hematologic neoplasm, characterized by a blockage of differentiation and an unconstrained proliferation of immature myeloid cells. Recently, the survival of leukemia patients has increased thanks to the use of differentiating agents, though these may cause serious side effects. Hence, the search for safer differentiating compounds is necessary. Our aim was to assess the pro-differentiating effects of a flavonoid-rich extract of bergamot juice (BJe) in human monocytic leukemia THP-1 cells, an in vitro AML model. For the first time, we showed that treatment with BJe induced differentiation of THP-1 cells, changes in cell morphology and increased expression of differentiation-associated surface antigens CD68, CD11b and CD14. Moreover, BJe enhanced protein levels of autophagy-associated markers, such as Beclin-1 and LC3, as well as induced the phosphorylation of the MAPKs JNK, ERK and p38, hence suggesting a potential mechanism underlying its antiproliferative effects. Indeed, parallel experiments highlighted that BJe was able to hamper THP-1 cell growth. In conclusion, our study suggests that BJe induces the differentiation of THP-1 cells and reduces their proliferation, highlighting its potential in differentiation therapy of AML.