Promyelocytic Leukemia Research Articles

Therapeutic potential of xtr-miR-22-3p from Plastrum testudinis in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is marked by a block at the promyelocyte stage. Treatments like ATRA and ATO face resistance and relapse issues. Plastrum testudinis, a traditional Chinese medicine, may offer therapeutic potential. This study investigated xtr-miR-22-3p from P. testudinis for treating APL. High expression of xtr-miR-22-3p was confirmed, with target prediction indicating interactions with key genes, including PML. xtr-miR-22-3p reduced HL-60 leukemia cell growth, altered the cell cycle, and selectively inhibited HL-60 proliferation while promoting BMSC growth, suggesting its potential as a targeted APL therapy.

An Atypical Mechanism of SUMOylation of Neurofibromin SecPH Domain Provides New Insights into SUMOylation Site Selection

Neurofibromin (Nf1) is a giant multidomain protein encoded by the tumour-suppressor gene NF1. NF1 is mutated in a common genetic disease, neurofibromatosis type I (NF1), and in various cancers. The protein has a Ras-GAP (GTPase activating protein) activity but is also connected to diverse signalling pathways through its SecPH domain, which interacts with lipids and different protein partners. We previously showed that Nf1 partially colocalized with the ProMyelocytic Leukemia (PML) protein in PML nuclear bodies, hotspots of SUMOylation, thereby suggesting the potential SUMOylation of Nf1. Here, we demonstrate that the full-length isoform 2 and a SecPH fragment of Nf1 are substrates of the SUMO pathway and identify a well-defined SUMOylation profile of SecPH with two main modified lysines. One of these sites, K1731, is highly conserved and surface-exposed. Despite the presence of an inverted SUMO consensus motif surrounding K1731, and a potential SUMO-interacting motif (SIM) within SecPH, we show that neither of these elements is necessary for K1731 SUMOylation, which is also independent of Ubc9 SUMOylation on K14. A 3D model of an interaction between SecPH and Ubc9 centred on K1731, combined with site-directed mutagenesis, identifies specific structural elements of SecPH required for K1731 SUMOylation, some of which are affected in reported NF1 pathogenic variants. This work provides a new example of SUMOylation dependent on the tertiary rather than primary protein structure surrounding the modified site, expanding our knowledge of mechanisms governing SUMOylation site selection.

MitoBADY-based Raman sensing of neutrophil-like cells

The aim was to evaluate the potential of MitoBADY as a Raman sensor in monitoring the drug-induced differentiation of promyelocytic cells into neutrophils. Neutrophils are important immune system components, and their metabolic disorders lead to serious diseases. Primary neutrophils found in the bloodstream are short-lived cells, terminally differentiated, and unable to proliferate. Thus, the characteristics of induced differentiation of promyelocytic cells are valuable for better chemotherapy design, as it is difficult to conduct such studies in vivo or ex vivo in bone marrow environments. Alternatively, a stable in vitro model can be used to analyze the differentiation process, e.g., the HL-60 promyelocytic leukemia cell line. The standard method to confirm the promyelocytic differentiation is immunophenotyping, which is complex and laborious. Here, we propose a simple spectroscopic-based alternative that uses the Raman signal of the MitoBADY sensor to identify neutrophil-like cells. We found that the ratio of the intensity of three bands, i.e., A= (I750+I2220)/I750, B=(I2850+I2220)/I2850, and A/B, of the Raman spectra of cells incubated with the MitoBADY is a specific marker indicating the induction of neutrophil differentiation of HL-60 cells. Flow cytometry, measuring the level of the expression of the CD11b surface protein, was used as a reference method. Raman measurements allowed the classification of neutrophil-like cells with a sensitivity of 79.8 % and a specificity of 79.5 %. These values demonstrate the great potential of the proposed methodology as a rapid and reliable technique for the evaluation of the differentiation of promyelocytic cells into neutrophils.

Characterization and functional analysis of chicken promyelocytic leukemia protein

In mammals, promyelocytic leukemia (PML) protein, also named as TRIM19, is the key component of nuclear membrane-less sub structures PML nuclear bodies (PML-NBs) or nuclear domains 10 (ND10). PML-NBs are dynamic foci that consist of numerous permanently or transiently associated proteins. The mammalian PMLs are involved in the regulation of various cellular pathways, including apoptosis, intrinsic and innate antiviral immunity, cell cycle, DNA damage, senescence and etc. Nevertheless, little is known about the role of chicken PML (chPML). In this study, chPML gene was cloned, and its several functions were characterized. We found that chPML was widely expressed in different tissues of chickens, and showed different subcellular distribution pattern in DF-1 cells comparing with LMH and HD11 cells. Like human PML, chPML was identified to be SUMOylated. K463 is one critical SUMOylation site and 240RARRG244 is SUMO interaction motif (SIM) of chPML. Moreover, qPCR showed that chPML could not only up-regulate the expression of host innate immune factor IFN-β and its downstream ISGs, but also antigen presentation-related factors including class II transactivator (CIITA) and MHC II DM beta 2 (DMB2). Notably, over-expression of chIFN-β could promote the expression of endogenous chPML. All these provide novel insights into the function of chPML, and pave the way for further studying the roles of chPML in biological process and anti-infection function.

Analysis of early death in critically ill patients with acute promyelocytic leukaemia in the HICU

This study was conducted to identify the characteristics and risk factors for early death in critically ill acute promyelocytic leukaemia (APL) patients in the Hemato-oncology ICU (HICU). A total of 44 APL patients from 2017 to 2023 were included. The mortality among APL patients in the HICU was high (27/44, 61.36%). Compared with patients who survived, nonsurvivors had a longer prothrombin time (P = 0.002), lower fibrinogen (P = 0.022), higher white blood cell count (P = 0.004) and higher creatinine (P = 0.037) on hosipital admission. Severe bleeding was the most frequent complication (34 cases, 77.27%), which occurred either preinduction or on Day 5 (IQR 3–7.5 days) of induction. Cerebral bleeding associated with consciousness disturbance was the main reason for HICU admission (18 cases, 40.9%). The leading cause of death was fatal haemorrhage (18/34, 52.94%), which occurred either preinduction or on Day 4 (IQR 3–7 days) of induction. Another common cause of death was sepsis (8/18, 44.44%), which occurred on Day 12 (IQR 9.5–24.75 days) during induction. In conclusion, the main cause of death in APL patients treated in the HICU was primary being attributed to fatal bleeding, followed by sepsis.

Clinical characteristics and analysis of related factors associated with early death in newly diagnosed patients with acute promyelocytic leukemia

ObjectiveThe objective of this study was to investigate the clinical characteristics and analysis of related factors associated with early death in newly diagnosed patients with acute promyelocytic leukemia (APL).MethodsThis retrospective study included patients who visited our hospital between January 2010 and August 2022 and were diagnosed with APL for the first time. We analyzed their clinical and laboratory characteristics and analysis of related factors associated with early death.ResultsA total of 269 patients with a primary diagnosis of APL were collected. The male to female ratio was 6:5, and the median age was 42 years (range 7–80). Among patients with initial APL diagnosis, there were 34 early deaths, resulting in an early mortality rate of 13%. The median time from diagnosis to death was 8.5 days (range 3–24). Comparative analysis of the clinical characteristics between patients who died early and those who did not, using a logistic regression model, revealed that age, white blood cell count (WBC) at initial diagnosis, and prolongation time of prothrombin time (PT) were independent risk factors for early death in patients with primary APL (P < 0.05). Comparing the clinical characteristics during hospitalization between the early death group and the non-early death group, it was observed that the daily mean of WBC during hospitalization was significantly higher in patients who died early than in those who did not (P < 0.001). Conversely, the daily mean of platelet count (PLT) was significantly lower in patients who died early compared to those who did not (P < 0.001). Furthermore, statistically significant differences were found in the mean daily infusion of PLT (P < 0.05), fibrinogen (Fib) (P < 0.05), and fresh frozen plasma (FFP) (P < 0.05) during hospitalization between patients who died early and those who did not. Specifically, the mean daily infusion of PLT and FFP was significantly higher in the early-death group than in the non-early-death group. Cerebral hemorrhage was identified as the immediate cause of death in 25 out of the 34 early-death patients (74%). The remaining causes of death included infection in 5 cases (15%), all of which were severe pulmonary infections, including 2 cases of combined differentiation syndrome, and abandonment of treatment in 4 patients (11%) at initial diagnosis.ConclusionIn patients with primary APL, age, WBC at initial diagnosis, and PT prolongation time were identified as independent risk factors for early death (P < 0.05). Laboratory findings regarding WBC and PLT during hospitalization, as well as the infusion of PLT, Fib, and FFP during hospitalization, were also statistically significant. Cerebral hemorrhage was found to be the main cause of early death in patients with primary APL.

TGF-β Signaling-Mediated Upregulation of Podoplanin: A Promising Biomarker for Diagnosis and Prognosis in Acute Promyelocytic Leukemia

TGF-β Signaling-Mediated Upregulation of Podoplanin: A Promising Biomarker for Diagnosis and Prognosis in Acute Promyelocytic Leukemia

AML-182 TGF-β Signaling-Mediated Upregulation of Podoplanin: A Promising Biomarker for Diagnosis and Prognosis in Acute Promyelocytic Leukemia

AML-182 TGF-β Signaling-Mediated Upregulation of Podoplanin: A Promising Biomarker for Diagnosis and Prognosis in Acute Promyelocytic Leukemia

Synchronous Diagnosis of Acute Promyelocytic Leukemia (APL) and Relapsed Breast Cancer (RBC)

Synchronous Diagnosis of Acute Promyelocytic Leukemia (APL) and Relapsed Breast Cancer (RBC)

Survival and Toxicity of Acute Promyelocytic Leukemia in Children: Single-Center Experience in Tashkent

Survival and Toxicity of Acute Promyelocytic Leukemia in Children: Single-Center Experience in Tashkent

AML-715 Treatment of Acute Promyelocytic Leukemia in Patients With Renal Failure on Hemodialysis

AML-715 Treatment of Acute Promyelocytic Leukemia in Patients With Renal Failure on Hemodialysis

Treatment of Acute Promyelocytic Leukemia in Patients With Renal Failure on Hemodialysis

Treatment of Acute Promyelocytic Leukemia in Patients With Renal Failure on Hemodialysis

Distinctive features associated with differentiation syndrome in acute promyelocytic leukemia in patients treated by all-trans retinoic acid and arsenic trioxide

In acute promyelocytic leukemia (APL), the combination treatment of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) appears to have a synergistic effect. Due to this synergism, differentiation syndrome (DS) in APL assumes a distinct identity separate from the formerly known ATRA syndrome, with distinct temporal patterns, diagnostic parameters, and clinical behavior. We retrospectively evaluated single-center data of years 2013–2022. Patients with newly diagnosed APL were categorized into three groups (16 patients in ATRA/ATO standard-risk group, 3 patients in ATRA/chemotherapy standard-risk group, and 5 patients in ATRA/chemotherapy high-risk group). Our aim was to analyze leukocytosis, signs of DS, and hepatic impairment within the first 25 days of treatment. The incidence of DS in the ATRA/ATO SR group was 43.8 %, with a median of 4 days and 2 days from ATRA and ATO initiation, respectively. This group also exhibited higher peak levels of leukocytosis 34.5 (6.0–113.4) x109/L (p = 0.0809). ALT elevation was more prevalent in the ATRA/ATO SR group (93.75 %), with 68.75 % grade 3–4 elevations (p = 0.0094). Importantly, all patients in this group had ALT levels that returned to normal during the subsequent consolidations. These findings suggest hepatopathy as a potential manifestation of ATRA/ATO induced leukocyte differentiation and/or DS. Diverse differentiation patterns were identified within the ATRA/ATO group, classifying patients into three distinct subgroups based on the concurrent dynamics of leukocytes and ALT levels, illustrating simultaneous, sequential, and divergent elevation patterns. These emphasize the different distribution of differentiation (organs vs. peripheral blood). We introduced real-world data and advocated for reevaluation of the current DS definition and associated diagnostic thresholds. Our study, conducted in a small country with a limited number of APL patients, acknowledges the inherent constraints in sample size. Further investigations with larger patient cohorts are warranted to validate and reinforce the outcomes observed in our study.

Histone chaperone HIRA, promyelocytic leukemia protein, and p62/SQSTM1 coordinate to regulate inflammation during cell senescence

Cellular senescence, a stress-induced stable proliferation arrest associated with an inflammatory senescence-associated secretory phenotype (SASP), is a cause of aging. In senescent cells, cytoplasmic chromatin fragments (CCFs) activate SASP via the anti-viral cGAS/STING pathway. Promyelocytic leukemia (PML) protein organizes PML nuclear bodies (NBs), which are also involved in senescence and anti-viral immunity. The HIRA histone H3.3 chaperone localizes to PML NBs in senescent cells. Here, we show that HIRA and PML are essential for SASP expression, tightly linked to HIRA's localization to PML NBs. Inactivation of HIRA does not directly block expression of nuclear factor κB (NF-κB) target genes. Instead, an H3.3-independent HIRA function activates SASP through a CCF-cGAS-STING-TBK1-NF-κB pathway. HIRA physically interacts with p62/SQSTM1, an autophagy regulator and negative SASP regulator. HIRA and p62 co-localize in PML NBs, linked to their antagonistic regulation of SASP, with PML NBs controlling their spatial configuration. These results outline a role for HIRA and PML in the regulation of SASP.

Analysis of the occurrence and liver function characteristics of arsenic-associated liver injury during the treatment of pediatric patients with acute promyelocytic leukemia.

Liver injury during arsenic treatment for acute promyelocytic leukemia was previously reported in adults, but not comprehensively in children until now. This study aims to investigate liver injury in pediatric patients with APL, changes in liver function during treatment, and compare the effects of Arsenic trioxide (ATO) and Realgar-Indigo naturalis formula (RIF) on liver function. One hundred and eighty-six patients with 3076 patient tests were analyzed, who were enrolled in the Chinese Children's Leukemia Group (CCLG)-APL2016 Protocol database between November 2016 and November 2018 in 38 hospitals across China(ChiCTR-OIN-17011227). Twenty of 164 patients (12.2%) suffered from liver injury after treatment with arsenic. In addition, sixteen (80%) cases of liver injury occurred during the induction period of treatment. What's not disheartening was that 18 (90%) cases of liver injury were transient, occurring at a median time of 17 days after exposure to arsenic. More importantly, the risk of liver injury associated with RIF was not higher than that associated with ATO (RR = 0.854, 95% CI: 0.292-2.495). Otherwise, the ALP of 18 cases of liver injury was not higher than the ULN of ALP. Thus, the incidence of liver injury associated with arsenic in pediatric patients with APL was similar to that in adult patients and the risk of liver injury associated with RIF was not higher than that associated with ATO. Since ALP was not higher in pediatric APL patients with liver injury, further research is needed to explore whether ALP is an index of liver injury in children.

Cancer-associated fibroblasts promote the proliferation and metastasis of colon cancer by mediating the RLIM/PML axis through paracrine COMP.

Cancer-associated fibroblasts (CAFs) are abundant in colon cancer (CC) patients with a poor prognosis. Here, the molecular regulatory mechanism of CAFs on CC growth and metastasis was explored. The genes' expression was monitored using RT-qPCR, immunoblotting, and immunohistochemistry. Cell viability and proliferation were found using CCK-8 and clone formation assays. The cell migration and invasion were probed using wound healing and Transwell. Co-IP was utilized for ascertaining the interaction between AKT and the ring finger protein, LIM domain interacting (RLIM). The in vivo murine subcutaneous tumor model and the metastasis model were built to further ascertain the axis. The result showed that CAFs motivate the growth and activate the PI3K/AKT pathway of CC cells via paracrine cartilage oligomeric matrix protein (COMP). Moreover, RLIM promoted the growth of CC cells, and its protein stability was regulated by AKT through its phosphorylation. Further, RLIM facilitated the ubiquitination and degradation of promyelocytic leukemia protein (PML). The in vitro and in vivo tests found that PML overexpression could inhibit CC's growth and metastasis, which were enhanced by CAFs. The COMP excreted from CAFs enhances the CC's growth and metastasis through regulating the RLIM/PML axis, supplying a new potential target for the cure of CC.

Successful treatment of acute promyelocytic leukemia with initial hyperleukocytosis, differentiated syndrome and massive intracranial hemorrhage in a child

Introduction. The development of hemorrhagic syndrome at the onset of the disease in patients with acute promyelocytic leukemia (APL) is one of the main causes of therapy failures and the most common cause of death in the early stages of remission induction. The risk of severe hemorrhagic complications increases in patients with the microgranular APL variant, often accompanied with hyperleukocytosis.Aim — to present a clinical case of successful diagnosis and treatment of primary APL with initial hyperleukocytosis in a patient with massive intracranial hemorrhage and differentiated syndrome.Main findings. A clinical observation of the diagnosis and treatment of APL in a 13-year-old patient with initial hyperleukocytosis, massive intracranial hemorrhage and differentiation syndrome is presented. Data on the variable manifestations of hemorrhagic syndrome in patients with APL and its effect on survival outcomes are also given. Diagnostic criteria and approaches in the treatment of differentiation syndrome are presented on the example of a clinical observation, when early clinical diagnosis and timely initiation of special antitumor treatment in the intensive care unit made it possible to achieve clinical, hematological and molecular remission, avoiding the fatal consequences of massive intracranial hemorrhage.

Eleven new glycosidic acid methyl esters from the crude resin glycoside fraction of Ipomoea alba seeds.

Resin glycosides are characteristic of plants of the Convolvulaceae family and are well-known purgative ingredients in crude drugs, such as Rhizoma Jalapae, Orizaba Jalapa Tuber, and Pharbitidis Semen, which are used in traditional medicine and derived from plants belonging to this family. Isolated resin glycosides have demonstrated diverse biological activities, including antibacterial, ionophoric, anti-inflammatory, antiviral, and multidrug-resistance-modulating properties, as well as cytotoxicity against cancer cells. These compounds consist of hydroxyl fatty acid oligoglycosides (glycosidic acids), with portions of the saccharide moieties acylated with some organic acids to form the core structure. This study investigated the glycosidic acid components of a crude resin glycoside fraction obtained from a methanolic extract of Ipomoea alba L. seeds (Convolvulaceae). Eleven new glycosidic acid methyl esters and one known methyl ester were isolated from a glycosidic acid fraction treated with trimethylsilyldiazomethane in hexane. Their structures were determined using acidic hydrolysis and electrospray ionization-time of fight mass spectrometry and NMR spectral analyses. These compounds are penta-, tetra-, or triglycosides, with methyl 11S-hydroxytetradecanoate or methyl 11S-hydroxyhexadecanoate as the aglycone. Although D-quinovose and L-rhamnose are common monosaccharide components, the remaining monosaccharides are D-glucose, D-xylose, or D-fucose. The crude resin glycoside fraction showed non-negligible cytotoxicity against HL-60 human promyelocytic leukemia cells.

Daxx mediated histone H3.3 deposition on HSV-1 DNA restricts genome decompaction and the progression of immediate-early transcription.

Herpesviruses are ubiquitous pathogens that cause a wide range of disease. Upon nuclear entry, their genomes associate with histones and chromatin modifying enzymes that regulate the progression of viral transcription and outcome of infection. While the composition and modification of viral chromatin has been extensively studied on bulk populations of infected cells by chromatin immunoprecipitation, this key regulatory process remains poorly defined at single-genome resolution. Here we use high-resolution quantitative imaging to investigate the spatial proximity of canonical and variant histones at individual Herpes Simplex Virus 1 (HSV-1) genomes within the first 90 minutes of infection. We identify significant population heterogeneity in the stable enrichment and spatial proximity of canonical histones (H2A, H2B, H3.1) at viral DNA (vDNA) relative to established promyelocytic leukaemia nuclear body (PML-NB) host factors that are actively recruited to viral genomes upon nuclear entry. We show the replication-independent histone H3.3/H4 chaperone Daxx to cooperate with PML to mediate the enrichment and spatial localization of variant histone H3.3 at vDNA that limits the rate of HSV-1 genome decompaction to restrict the progress of immediate-early (IE) transcription. This host response is counteracted by the viral ubiquitin ligase ICP0, which degrades PML to disperse Daxx and variant histone H3.3 from vDNA to stimulate the progression of viral genome expansion, IE transcription, and onset of HSV-1 replication. Our data support a model of intermediate and sequential histone assembly initiated by Daxx that limits the rate of HSV-1 genome decompaction independently of the stable enrichment of histones H2A and H2B at vDNA required to facilitate canonical nucleosome assembly. We identify HSV-1 genome decompaction upon nuclear infection to play a key role in the initiation and functional outcome of HSV-1 lytic infection, findings pertinent to the transcriptional regulation of many nuclear replicating herpesvirus pathogens.

Phase separation of PML/RARα and BRD4 coassembled microspeckles governs transcriptional dysregulation in acute promyelocytic leukemia

In acute promyelocytic leukemia (APL), the promyelocytic leukemia-retinoic acid receptor alpha (PML/RARα) fusion protein destroys PML nuclear bodies (NBs), leading to the formation of microspeckles. However, our understanding, largely learned from morphological observations, lacks insight into the mechanisms behind PML/RARα-mediated microspeckle formation and its role in APL leukemogenesis. This study presents evidence uncovering liquid-liquid phase separation (LLPS) as a key mechanism in the formation of PML/RARα-mediated microspeckles. This process is facilitated by the intrinsically disordered region containing a large portion of PML and a smaller segment of RARα. We demonstrate the coassembly of bromodomain-containing protein 4 (BRD4) within PML/RARα-mediated condensates, differing from wild-type PML-formed NBs. In the absence of PML/RARα, PML NBs and BRD4 puncta exist as two independent phases, but the presence of PML/RARα disrupts PML NBs and redistributes PML and BRD4 into a distinct phase, forming PML/RARα-assembled microspeckles. Genome-wide profiling reveals a PML/RARα-induced BRD4 redistribution across the genome, with preferential binding to super-enhancers and broad-promoters (SEBPs). Mechanistically, BRD4 is recruited by PML/RARα into nuclear condensates, facilitating BRD4 chromatin binding to exert transcriptional activation essential for APL survival. Perturbing LLPS through chemical inhibition (1, 6-hexanediol) significantly reduces chromatin co-occupancy of PML/RARα and BRD4, attenuating their target gene activation. Finally, a series of experimental validations in primary APL patient samples confirm that PML/RARα forms microspeckles through condensates, recruits BRD4 to coassemble condensates, and co-occupies SEBP regions. Our findings elucidate the biophysical, pathological, and transcriptional dynamics of PML/RARα-assembled microspeckles, underscoring the importance of BRD4 in mediating transcriptional activation that enables PML/RARα to initiate APL.