Cytoreductive chemotherapy in induction therapy plays a key role in the prognosis of patients with low-risk acute promyelocytic leukaemia.

In order to explore the risk factors of relapse and potential optimized therapeutic regimen of low-risk acute promyelocytic leukaemia (APL), here we retrospectively analysed 282 patients who were diagnosed between February 2014 and September 2021. The median follow-up was 59 (9-102) months. The 5-year overall survival and cumulative relapse incidence were 97.9% and 5.9%, respectively. In terms of different cytoreductive therapies, 86 patients were administered with hydroxycarbamide (30.5%), 113 with anthracyclines or cytarabine (40.1%), 31 with etoposide (11.0%) and 52 with no cytoreductive therapy (18.4%) during the induction therapy. The hydroxycarbamide treatment group did not decrease the relapse rate compared to the no cytoreduction group (11.4% vs. 5.9%, p = 0.289). Compared with the hydroxycarbamide group, the anthracyclines/cytarabine treatment group showed improved 5-year RFS (88.145% vs. 98.113%, p = 0.008). Multivariate Cox regression analysis revealed that myeloblasts in bone marrow at diagnosis, and PML-RARA transcript level of 6.5% or more after induction therapy were associated with a subsequent risk of relapse. The only factor positively reducing the relapse rate was anthracyclines/cytarabine cytoreductive treatment. In conclusion, cytoreductive chemotherapy in induction therapy plays a potential key role in the prognosis of low-risk APL.

Identification of triciribine as a novel myeloid cell differentiation inducer.

Differentiation therapy using all-trans retinoic acid (ATRA) for acute promyelocytic leukemia (APL) is well established. However, because the narrow application and tolerance development of ATRA need to be improved, we searched for another efficient myeloid differentiation inducer. Kinase activation is involved in leukemia biology and differentiation block. To identify novel myeloid differentiation inducers, we used a Kinase Inhibitor Screening Library. Using a nitroblue tetrazolium dye reduction assay and real-time quantitative PCR using NB4 APL cells, we revealed that, PD169316, SB203580, SB202190 (p38 MAPK inhibitor), and triciribine (TCN) (Akt inhibitor) potently increased the expression of CD11b. We focused on TCN because it was reported to be well tolerated by patients with advanced hematological malignancies. Nuclear/cytoplasmic (N/C) ratio was significantly decreased, and myelomonocytic markers (CD11b and CD11c) were potently induced by TCN in both NB4 and acute myeloid leukemia (AML) M2 derived HL-60 cells. Western blot analysis using NB4 cells demonstrated that TCN promoted ERK1/2 phosphorylation, whereas p38 MAPK phosphorylation was not affected, suggesting that activation of the ERK pathway is involved in TCN-induced differentiation. We further examined that whether ATRA may affect phosphorylation of ERK and p38, and found that there was no obvious effect, suggesting that ATRA induced differentiation is different from TCN effect. To reveal the molecular mechanisms involved in TCN-induced differentiation, we performed microarray analysis. Pathway analysis using DAVID software indicated that "hematopoietic cell lineage" and "cytokine-cytokine receptor interaction" pathways were enriched with high significance. Real-time PCR analysis demonstrated that components of these pathways including IL1ß, CD3D, IL5RA, ITGA6, CD44, ITGA2B, CD37, CD9, CSF2RA, and IL3RA, were upregulated by TCN-induced differentiation. Collectively, we identified TCN as a novel myeloid cell differentiation inducer, and trials of TCN for APL and non-APL leukemia are worthy of exploration in the future.

Reinvent Aliphatic Arsenicals as Reversible Covalent Warheads toward Targeted Kinase Inhibition and Non-acute Promyelocytic Leukemia Cancer Treatment.

The success of arsenic in acute promyelocytic leukemia (APL) treatment is hardly transferred to non-APL cancers, mainly due to the low selectivity and weak binding affinity of traditional arsenicals to oncoproteins critical for cancer survival. We present herein the reinvention of aliphatic trivalent arsenicals (As) as reversible covalent warheads of As-based targeting inhibitors toward Bruton's tyrosine kinase (BTK). The effects of As warheads' valency, thiol protection, methylation, spacer length, and size on inhibitors' activity were studied. We found that, in contrast to the bulky and rigid aromatic As warhead, the flexible aliphatic As warheads were well compatible with the well-optimized guiding group to achieve nanomolar inhibition against BTK. The optimized As inhibitors effectively blocked the BTK-mediated oncogenic signaling pathway, leading to elevated antiproliferative activities toward lymphoma cells and xenograft tumor. Our study provides a promising strategy enabling rational design of new aliphatic arsenic-based reversible covalent inhibitors toward non-APL cancer treatment.

A Life-Threatening Complication During the Fourth Pregnancy Due to Acute Promyelocytic Leukemia: A Case Report.

Incidents of leukemia in pregnancy are infrequent with only one case found from 75,000 to 100,000 pregnancies. The pathophysiological mechanism of leukemia during pregnancy is still unclear. Leukemia which occurs in pregnancy is usually acute and predominantly the myeloid type.A 35-year-old woman in her fourth pregnancy with a gestational age of 38-39 weeks, came to the emergency department (ED) with complaints of contractions since 4.5 hours before admission. The contraction was not accompanied by discharge, mucus, or blood, and fetal movements was still active. She denied complaints of fever, nausea, vomiting, dizziness, shortness of breath, weakness, fatigue, lethargy, and bleeding. Physical examination results, both palpebral conjunctiva were pale. Laboratory examination results of a complete blood count, white blood cell count were 2,930/uL, hemoglobin 8.3 g/dL, Hct 24.10%, erythrocytes 2.78x106/µL, platelets 62,000/µL. Bone Marrow Aspiration (BMA) revealed Acute Promyelocytic Leukemia (APL).APL is a subtype of Acute Myelogenous Leukemia (AML). Persistent fatigue, recurrent infections, and bleeding are common manifestations of APL. The diagnosis of APL is made by bone marrow aspiration examination, and it is safe for pregnancy. APL therapy in pregnancy uses All-Trans Retinoic Acid (ATRA) and Arsenic Trioxide (ATO). ATRA and ATO are highly teratogenic, but recent studies have reported no fetal abnormalities.Accuracy and speed in diagnosing and initiating APL therapy in pregnancy are essential in preventing serious complications.

Fucosylation inhibitor 6-alkynylfucose enhances the ATRA-induced differentiation effect on acute promyelocytic leukemia cells.

For acute promyelocytic leukemia (APL), differentiation therapy with all-trans retinoic acid (ATRA) is well established. However, the narrow application and tolerance development of ATRA remain to be improved. In this study, we investigated the effects of combinations of glycosylation inhibitors with ATRA to achieve better efficiency than ATRA alone. We found that the combination of fucosylation inhibitor 6-alkynylfucose (6AF) and ATRA had an additional effect on cell differentiation, as revealed by expression changes in two differentiation markers, CD11b and CD11c, and significant morphological changes in NB4 APL and HL-60 acute myeloid leukemia (AML) cells. In AAL lectin blot analyses, ATRA or 6AF alone could decrease fucosylation, while their combination decreased fucosylation more efficiently. To clarify the molecular mechanism for the 6AF effect on ATRA-induced differentiation, we performed microarray analyses using NB4 cells. In a pathway analysis using DAVID software, we found that the C-type lectin receptor (CLR) signaling pathway was enriched with high significance. In real-time PCR analyses using NB4 and HL-60 cells, FcεRIγ, CLEC6A, CLEC7A, CASP1, IL-1ß, and EGR3, as components of the CLR pathway, as well as CD45 and AKT3 were upregulated by 6AF in ATRA-induced differentiation. Taken together, the present findings suggest that the CLR signaling pathway is involved in the 6AF effect on ATRA-induced differentiation.

The influence of hospital volume and physician volume on early mortality in acute promyelocytic leukemia patients.

Acute promyelocytic leukemia (APL) is a highly curable hematologic malignancy in the era of all-trans retinoic acid (ATRA) combination treatment. However, only a modest change in early mortality rate has been observed despite the wide availability of ATRA. In addition to the clinical characteristics of APL patients, studies on the hospital volume-outcome relationship and the physician volume-outcome relationship remained limited. We aim to evaluate the association between hospital and physician volume and the early mortality rate among APL patients. The patients were collected from Taiwan's National Health Insurance Research Database (NHIRD). Early mortality is defined as death within 30 days of diagnosis. Patients were categorized into four groups according to individual cumulative hospital and physician volume. The risk of all-cause mortality in APL patients with different cumulative volume groups was compared using a Cox proportional hazard model. The probability of overall survival was estimated using the Kaplan-Meier method. All 741 patients were divided into four quartile volume groups. In the multivariate analysis, only physician volume was significantly associated with early mortality rate. The physician volume of the highest quartile was a protective factor for early mortality compared with the physician volume of the lowest quartile (HR 0.10, 95% CI 0.02-0.65). Hospital characteristics were not associated with early mortality. In the sensitivity analyses, the results remained consistent using two other different definitions of early mortality. Higher physician volume was independently associated with lower early mortality, while hospital volume was not. Enhancing the clinical expertise of low-volume physicians may ensure better outcomes.

A Case of Relapsed/Refractory CD56-Positive Acute Promyelocytic Leukemia, in Which Complete Molecular Remission Was Achieved Following Combination Therapy with Venetoclax and Azacitidine.

An 84-year-old woman was diagnosed as having acute promyelocytic leukemia(APL)in July Year X-3. The test for promyelocytic leukemia- retinoic acid receptor alpha(PML-RARA)mRNA was positive, while that for CD56 was negative. Since her white blood cell( WBC) count was <3,000/µL, with a count of APL cells of <1,000/µL, she was started on monotherapy with all-trans retinoic acid(ATRA). In September Year X-3, complete hematological remission(CHR)was confirmed. she refused to provide consent for receiving consolidation therapy. In February Year X-2, hematological relapse occurred. She was started on re-induction therapy with arsenite(ATO), and in June Year X-2, complete molecular remission(CMR)was achieved. She was started on post-remission therapy with ATO. In August Year X-1, she developed molecular relapse and was started on tamibarotene(Am80). In October Year X-1, hematological relapse was detected, and the test for CD56 was positive. She was started on combined venetoclax(VEN)+azacitidine(AZA)(VEN+AZA). After completion of 1 course of treatment, CMR was achieved, but she developed hematological relapse after 5 courses of treatment. She died of gastrointestinal hemorrhage. This is considered a valuable case for accumulating information on the treatment of CD56-positive APL resistant to ATRA and ATO.

Superiority of anthracycline-free treatment in standard-risk acute promyelocytic leukemia: A systematic review and comparative epidemiological analysis.

BACKGROUND: Recent advances in the treatment of acute promyelocytic leukemia (APML) have seen unprecedented improvements in patient outcomes. However, such rapid growth in understanding often leads to uncertainty regarding superiority among candidate treatment regimens, especially when further scrutinized from an epidemiological perspective. AIMS: The aim of this systematic review with epidemiological analysis was to identify and compare commonly utilized protocols for standard-risk APML with a particular focus on complete remission (CR), overall/disease-free survival (DFS), and reported adverse events. METHODS AND RESULTS: Medline, Scopus, and CINAHL were interrogated to identify studies utilizing all-trans retinoic acid (ATRA) in addition to arsenic trioxide (ATO) and/or anthracyclines such as idarubicin (IDA) in the treatment of de-novo APML. After collation of studies, an epidemiological analysis was subsequently performed to compare protocols with regards to outcomes of interest using number needed to benefit (NNB) and number needed to harm (NNH) measures. Seventeen articles, describing 12 distinct trials, were included in the analysis. These trials made use of three unique protocols; CR rates were 94%-100% for ATO/ATRA regimens, 95%-96% for ATO/ATRA/anthracycline regimens, and 89%-94% for ATRA/anthracycline regimens. Epidemiological analysis demonstrated NNB for CR was 9.09 (ATO/ATRA vs. ATRA/IDA) and 20.00 (ATO/ATRA vs. ATO/ATRA/IDA), NNH for neutropenia was -3.45 (ATO/ATRA vs. ATRA/IDA), and NNH for infection was -3.13 (ATO/ATRA vs. ATRA/IDA) and -1.89 (ATO/ATRA vs. ATO/ATRA/IDA). CONCLUSION: The ATO/ATRA regimen is superior to chemotherapy-containing protocols at inducing remission and promoting survival in patients with APML. The regimen is better tolerated than the proposed alternatives with fewer adverse events. Future research opportunities include quantifying APML epidemiology and pursuing oral arsenic as an option for simplification of therapeutic protocols.

Disseminated intravascular coagulation score evolution in 48 h predicts early death in acute promyelocytic leukemia patients.

INTRODUCTION: Early death (ED) is the unsolved issue of acute promyelocytic leukemia (APL). The disseminated intravascular coagulation (DIC) score has been proposed as a marker of bleeding and death in APL; whether its temporal evolution predicts outcomes in APL is unknown. We evaluated whether an increasing score 48 h after diagnosis associates with ED. METHODS: Retrospective, single-center study, including patients with newly diagnosed APL between 2000 and 2023, treated with all-transretinoic acid (ATRA) plus anthracycline or arsenic trioxide (ATO). "DIC score worsening" was defined as ≥1 point increase in the score after 48 h, and ED as death within 30 days of diagnosis. RESULTS: Eighty-six patients were included, with median age of 46 years (17-82). ED patients (26.7%) more frequently had age >60 years and worsening DIC score after 48 h. These were also the only predictors of ED identified in both univariate and multivariate (OR 4.18, p = .011; OR 7.8, p = .005, respectively) logistic regression analysis. CONCLUSION: This is the first study on DIC score evolution in APL-a worsening DIC score 48 h after diagnosis is a strong independent predictive factor of ED. We propose a reduction of the DIC score from diagnosis as a new treatment goal in APL care.

Cellular and micro-environmental responses influencing the antitumor activity of all-trans retinoic acid in breast cancer.

All-trans retinoic acid (ATRA) is the most relevant and functionally active metabolite of Vitamin-A. From a therapeutic standpoint, ATRA is the first example of pharmacological agent exerting its anti-tumor activity via a cell differentiating action. In the clinics, ATRA is used in the treatment of Acute Promyelocytic Leukemia, a rare form of myeloid leukemia with unprecedented therapeutic results. The extraordinary effectiveness of ATRA in the treatment of Acute Promyelocytic Leukemia patients has raised interest in evaluating the potential of this natural retinoid in the treatment of other types of neoplasias, with particular reference to solid tumors.The present article provides an overview of the available pre-clinical and clinical studies focussing on ATRA as a therapeutic agent in the context of breast cancer from a holistic point of view. In detail, we focus on the direct effects of ATRA in breast cancer cells as well as the underlying molecular mechanisms of action. In addition, we summarize the available information on the action exerted by ATRA on the breast cancer micro-environment, an emerging determinant of the progression and invasive behaviour of solid tumors. In particular we discuss the recent evidences of ATRA activity on the immune system. Finally, we analyse and discuss the results obtained with the few ATRA-based clinical trials conducted in the context of breast cancer.

Research on different compound combinations of Realgar-Indigo naturalis formula to reverse acute promyelocytic leukemia arsenic resistance by regulating autophagy through mTOR pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: In China, the Chinese patent drug Realgar-Indigo naturalis Formula (RIF) is utilized for the therapy of acute promyelocytic leukemia (APL). Comprising four traditional Chinese herb-Realgar, Indigo naturalis, Salvia miltiorrhiza, and Pseudostellaria heterophylla-it notably includes tetra-arsenic tetra-sulfide, indirubin, tanshinone IIa, and total saponins of Radix Pseudostellariae as its primary active components. Due to its arsenic content, RIF distinctly contributes to the therapy for APL. However, the challenge of arsenic resistance in APL patients complicates the clinical use of arsenic agents. Interestingly, RIF demonstrates a high remission rate in APL patients, suggesting that its efficacy is not significantly compromised by arsenic resistance. Yet, the current state of research on RIF's ability to reverse arsenic resistance remains unclear. AIM OF THE STUDY: To investigate the mechanism of different combinations of the compound of RIF in reversing arsenic resistance in APL. MATERIALS AND METHODS: The present study utilized the arsenic-resistant HL60-PMLA216V-RARα cell line to investigate the effects of various RIF compounds, namely tetra-arsenic tetra-sulfide (A), indirubin (I), tanshinone IIa (T), and total saponins of Radix Pseudostellariae (S). The assessment of cell viability, observation of cell morphology, and evaluation of cell apoptosis were performed. Furthermore, the mitochondrial membrane potential, changes in the levels of PMLA216V-RARα, apoptosis-related factors, and the PI3K/AKT/mTOR pathway were examined, along with autophagy in all experimental groups. Meanwhile, we observed the changes about autophagy after blocking the PI3K or mTOR pathway. RESULTS: Tanshinone IIa, indirubin and total saponins of Radix Pseudostellariae could enhance the effect of tetra-arsenic tetra-sulfide down-regulating PMLA216V-RARα, and the mechanism was suggested to be related to inhibiting mTOR pathway to activate autophagy. CONCLUSIONS: We illustrated that the synergistic effect of different compound combinations of RIF can regulate autophagy through the mTOR pathway, enhance cell apoptosis, and degrade arsenic-resistant PMLA216V-RARα.

PML Nuclear bodies: the cancer connection and beyond.

Promyelocytic leukemia (PML) nuclear bodies, membrane-less organelles in the nucleus, play a crucial role in cellular homeostasis. These dynamic structures result from the assembly of scaffolding PML proteins and various partners. Recent crystal structure analyses revealed essential self-interacting domains, while liquid-liquid phase separation contributes to their formation. PML bodies orchestrate post-translational modifications, particularly stress-induced SUMOylation, impacting target protein functions. Serving as hubs in multiple signaling pathways, they influence cellular processes like senescence. Dysregulation of PML expression contributes to diseases, including cancer, highlighting their significance. Therapeutically, PML bodies are promising targets, exemplified by successful acute promyelocytic leukemia treatment with arsenic trioxide and retinoic acid restoring PML bodies. Understanding their functions illuminates both normal and pathological cellular physiology, guiding potential therapies. This review explores recent advancements in PML body biogenesis, biochemical activity, and their evolving biological roles.

Arsenic-induced neurotoxicity in patients with acute promyelocytic leukaemia.

Arsenic trioxide is an essential component of therapy for acute promyelocytic leukaemia (APL) and is currently dosed on actual body weight with no upper limit. Arsenic-induced neurotoxicity is a well-recognised complication; however, there is uncertainty about its relationship to arsenic dose and obesity. We conducted a large multicentre retrospective study of 487 patients with APL treated with arsenic-based therapy across 23 sites in Australia from 2008 to 2023. The primary outcome was incidence of neurotoxicity, and secondary outcomes included relationship of neurotoxicity to obesity and cumulative arsenic dose. Any-grade neurotoxicity occurred in 113 (23%) patients, predominantly peripheral neuropathy (91%). Most events were grade 1-2 severity (85%), with grade 3 events in 12% and grade 4-5 in 3%. The incidence of neurotoxicity increased with BMI (non-obese: 16%, obesity class I: 25%, obesity class II-III: 41%; p < 0.001). On univariable analysis, obesity class I (OR 1.81, p = 0.036), obesity class II-III (OR 3.93, p < 0.001), weight >100 kg (OR 2.72, p < 0.001), daily arsenic trioxide dose >15 mg (OR 5.05, p < 0.001) and cumulative induction dose >500 mg (OR 3.95, p < 0.001) were all significantly associated with neurotoxicity. Obesity class II-III and induction dose >500 mg remained significant on multivariable analysis. Our study highlights the strong association between BMI, arsenic trioxide dose and neurotoxicity. Pre-emptive dose reductions should be considered for obese patients receiving high doses of arsenic.

A case report of acute promyelocytic leukemia with mycosis fungoides.

RATIONALE: Acute promyelocytic leukaemia (APL) is a rare subtype of acute myelogenous leukaemia. With advances in treatment regimens, namely, introduction of all-trans-retinoicacid, outcomes have drastically improved, its side effects should not be ignored. Mycosis fungoides is one of the side effects of all-trans-retinoicacid treatment, but it may also be a clinical manifestation before disease progression. However, it rarely appears and is easily overlooked. This leads to being easily misled during the treatment process, affecting the treatment plan, and resulting in adverse consequences. Therefore, early identification and judgment can not only provide appropriate treatment options, but also prevent and treat further disease progression. PATIENT CONCERNS: The patient was hospitalized for pancytopaenia. After completing the examination, the patient was finally diagnosed with acute promyelocytic leukaemia (acute myelogenous leukaemia-M3). We administered tretinoin and arsenous acid. Evaluation of the treatment effect on the 7th day after chemotherapy showed that the bone marrow morphology showed complete remission. After the second course of chemotherapy, the patient developed red miliary macular papules, which gradually worsened. After completing relevant inspections, Considering that the cases was complicated with skin mycosis fungoides, the patient was treated with budesonide ointment and methylprednisolone as chemotherapy. DIAGNOSES: Upon examination, the patient was initially diagnosed with acute promyelocytic leukaemia. Evaluation of the treatment effect on the 7th day after chemotherapy showed that the bone marrow morphology showed complete remission. After the second course of chemotherapy, we discovered the patient was diagnosed with skin mycosis fungoides. INTERVENTIONS: Systemic chemotherapy is first given when a patient was diagnosed with acute promyelocytic leukaemia. After the patient happened skin mycosis fungoides, We have adjusted the treatment plan and supplemented it with other treatment plans based on the original chemotherapy, After 2 months of treatment, his condition gradually improved. OUTCOMES: All-trans-retinoicacid in the treatment of APL must be given attention because mycosis fungoides should not only be distinguished from infectious diseases but also be further assessed with regard to disease progression and metastasis. LESSONS: Acute promyelocytic leukemia needs to be treated with arsenic trioxide. All-trans-retinoicacid in the treatment of APL must be given attention mycosis fungoides. Early diagnosis can guide accurate treatment, which is of great help in alleviating the pain of patients and improving the cure rate.

Identification of a novel fusion gene, RARA::ANKRD34C, in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is a specific subtype of acute myeloid leukemia that is distinguished by the chromosomal translocation t(15;17)(q24;q21), which leads to the fusion of the promyelocytic leukemia (PML) gene with the retinoic acid receptor alpha (RARA). Recently, we identified a novel fusion gene in APL, RARA::ankyrin repeat domain 34C (ANKRD34C), identified its functions by morphological, cytogenetic, molecular biological and multiplex fluorescence in situ hybridization analyses, and demonstrated the potential therapeutic effect clinically and experimentally of all-trans retinoic acid (ATRA); the findings have important implications for the diagnosis and treatment of atypical APL.

Clinical Indicators of Hepatotoxicity in Newly Diagnosed Acute Promyelocytic Leukemia Patients Undergoing Arsenic Trioxide Treatment.

Arsenic trioxide (ATO)-induced hepatotoxicity is often observed in acute promyelocytic leukemia (APL) patients and decreases therapeutic effect of ATO. Thus, concerns over hepatotoxicity have been raised. The aim of this study was to explore some noninvasive clinical indicators that can be used to guide the individualized application of ATO in the future. APL patients treated with ATO were identified retrospectively via electronic health records at our hospital from August 2014 through August 2019. APL patients without hepatotoxicity were selected as controls. The association between putative risk factors and ATO-induced hepatotoxicity was estimated with ORs and 95% CIs, which were calculated using the chi-square test. The subsequent multivariate analysis was performed using logistic regression analysis. In total, 58.04% of patients experienced ATO-induced hepatotoxicity during the first week. Elevated hemoglobin (OR 8.653, 95% CI, 1.339-55.921), administration of nonprophylactic hepatoprotective agents (OR 36.455, 95% CI, 7.409-179.364), non-single-agent ATO to combat leukocytosis (OR 20.108, 95% CI, 1.357-297.893) and decreased fibrinogen (OR 3.496, 95% CI, 1.127-10.846) were found to be statistically significant risk factors for ATO-induced hepatotoxicity. The area under the ROC curve values were 0.846 for "overall ATO-induced hepatotoxicity" and 0.819 for "early ATO-induced hepatotoxicity." The results revealed that hemoglobin ≥ 80 g/L, nonprophylactic hepatoprotective agents, and non-single-agent ATO and fibrinogen < 1 g/L are risk factors for ATO-induced hepatotoxicity in newly diagnosed APL patients. These findings can enhance the clinical diagnosis of hepatotoxicity. Prospective studies should be performed in the future to validate these findings.