Chronic myeloid leukaemia

Single-cell multiomics analysis of chronic myeloid leukemia links cellular heterogeneity to therapy response

The advent of tyrosine kinase inhibitors (TKIs) as treatment of chronic myeloid leukemia (CML) is a paradigm in molecularly targeted cancer therapy. Nonetheless, TKI-insensitive leukemia stem cells (LSCs) persist in most patients even after years of treatment and are imperative for disease progression as well as recurrence during treatment-free remission (TFR). Here, we have generated high-resolution single-cell multiomics maps from CML patients at diagnosis, retrospectively stratified by BCR::ABL1IS (%) following 12 months of TKI therapy. Simultaneous measurement of global gene expression profiles together with >40 surface markers from the same cells revealed that each patient harbored a unique composition of stem and progenitor cells at diagnosis. The patients with treatment failure after 12 months of therapy had a markedly higher abundance of molecularly defined primitive cells at diagnosis compared to the optimal responders. The multiomic feature landscape enabled visualization of the primitive fraction as a mixture of molecularly distinct BCR::ABL1+ LSCs and BCR::ABL1-hematopoietic stem cells (HSCs) in variable ratio across patients, and guided their prospective isolation by a combination of CD26 and CD35 cell surface markers. We for the first time show that BCR::ABL1+ LSCs and BCR::ABL1- HSCs can be distinctly separated as CD26+CD35- and CD26-CD35+, respectively. In addition, we found the ratio of LSC/HSC to be higher in patients with prospective treatment failure compared to optimal responders, at diagnosis as well as following 3 months of TKI therapy. Collectively, this data builds a framework for understanding therapy response and adapting treatment by devising strategies to extinguish or suppress TKI-insensitive LSCs.

RNA-loaded nanoparticles for the treatment of hematological cancers

Hematological cancers encompass a diverse group of malignancies affecting the blood, bone marrow, lymph nodes, and spleen. These disorders present unique challenges due to their complex etiology and varied clinical manifestations. Despite significant advancements in understanding and treating hematological malignancies, innovative therapeutic approaches are continually sought to enhance patient outcomes. This review highlights the application of RNA nanoparticles (RNA-NPs) in the treatment of hematological cancers. We delve into detailed discussions on in vitro and preclinical studies involving RNA-NPs for adult patients, as well as the application of RNA-NPs in pediatric hematological cancer. The review also addresses ongoing clinical trials involving RNA-NPs and explores the emerging field of CAR-T therapy engineered by RNA-NPs. Finally, we discuss the challenges still faced in translating RNA-NP research to clinics.

Structure optimization, synthesis and bioactivity evaluation of novel BCR-ABL tyrosine kinase inhibitor targeting T315I mutation

Chronic Myeloid Leukemia (CML) is a malignant hematologic tumor caused by BCR-ABL fusion protein that binds with ATP to exert tyrosinase activity and persistently activates downstream phosphorylation pathways. The tyrosine kinase inhibitors (TKIs) represented by Imatinib are the key clinical therapy to the CML. While the mutations on the target lead to the serious drug resistance problems, especially the T315I mutation remains an unresolved challenge, and the cardiotoxicity has limited the clinical application of the third generation TKI Ponatinib despite its favorable efficacy against the T315I mutation. Even though, structural optimization of Ponatinib remains a potential strategy to overcome the resistance imposed by the mutation. Herein, we present a series of novel BCR-ABL/T315I tyrosine kinase inhibitors obtained by virtual screening using ZINC21710815, a BCR-ABL/T315I inhibitor reported earlier by our team, as a lead compound, and structural optimization of lead compounds against the T315I mutation, as well as screening of two novel compounds by activity evaluation and mechanistic studies, W4 and W8. W4 and W8 have better cell death-inducing effects and special selectivity against BaF3/T315I, which are worthy of further in-depth study to obtain more desirable anti-CML drugs as lead compounds.

Efficacy and safety of olverembatinib in adult BCR::ABL1-positive ALL with T315I mutation or relapsed/refractory disease

Third-generation tyrosine kinase inhibitors (TKIs) have much potential for the treatment of BCR::ABL1-positive leukaemia, particularly that harbouring the ABL1 T315I mutation. Olverembatinib (HQP1351), a novel third-generation TKI, has favourable efficacy and safety profiles in chronic myeloid leukaemia. Here, we present the clinical findings from 31 BCR::ABL1-positive acute lymphoblastic leukaemia (ALL) patients who received olverembatinib. Among the 14 patients with overt relapsed/refractory (R/R) disease (including 10 with the T315I mutation), 71.4% achieved an overall response. Of the other 17 patients with minimal residual disease (MRD)-positive ALL (including 14 with the T315I mutation), 60.0% and 47.1% achieved MRD flow negativity and complete molecular remission, respectively. With a median follow-up time of 16.3 months, the median event-free survival and overall survival were 3.9 and 8.3 months respectively, in overt R/R patients, and 11.5 and 18.4 months in MRD-positive patients. Allogeneic haematopoietic stem cell transplantation further improved outcomes among responders. The safety profile was generally manageable. This study suggests that olverembatinib-based therapy is another promising option for BCR::ABL1-positive ALL in addition to ponatinib, especially for patients with MRD-positive disease and a single T315I mutation.

RNA-Binding Protein Lin28B Promotes Chronic Myeloid Leukemia Blast Crisis by Transcriptionally Upregulating miR-181d

The blast crisis (BC) of chronic myeloid leukemia (CML) has poor efficacy against existing treatments and extremely short survival. However, the molecular mechanism of CML-chronic phase (CP) transformation to CML-BC is not yet fully understood. Here, we show that Lin28B, an RNA-binding protein, acted as an activator enhancing the transformation to CML-BC by mediating excessive cell proliferation. The level of Lin28B expression was apparently elevated in patients with CML-BC compared with newly diagnosed patients with CML-CP. The overexpression of Lin28B promoted the proliferation of leukemia cells. Mechanistically, we identified Lin28B as a DNA-binding protein by binding to the promoter region of miR-181d and upregulating its expression, which inhibited the expression of programmed cell death 4 (PDCD4) by binding to the PDCD4 3'UTR region, thereby enhancing the proliferation of CML cells. Overall, the "Lin28B-miR-181d-PDCD4" regulatory axis promoted CML blast crisis. Implications: Our findings highlight the oncogenic role of Lin28B in CML blast crisis, acting as a DNA-binding protein that transcriptionally upregulates miR-181d expression.

Hsa_circ_0006010 and hsa_circ_0002903 in peripheral blood serve as novel diagnostic, surveillance and prognostic biomarkers for disease progression in chronic myeloid leukemia

BACKGROUND

In the era of tyrosine kinase inhibitor (TKI) treatment, the progression of chronic myeloid leukemia (CML) remains a significant clinical challenge, and genetic biomarkers for the early identification of CML patients at risk for progression are limited. This study explored whether essential circular RNAs (circRNAs) can be used as biomarkers for diagnosing and monitoring CML disease progression and assessing CML prognosis.

METHODS

Peripheral blood (PB) samples were collected from 173 CML patients (138 patients with chronic phase CML [CML-CP] and 35 patients with accelerated phase/blast phase CML [CML-AP/BP]) and 63 healthy controls (HCs). High-throughput RNA sequencing (RNA-Seq) was used to screen dysregulated candidate circRNAs for a circRNA signature associated with CML disease progression. Quantitative real-time PCR (qRT-PCR) was used for preliminary verification and screening of candidate dysregulated genes, as well as subsequent exploration of clinical applications. Receiver operating characteristic (ROC) curve analysis, Spearman's rho correlation test, and the Kaplan-Meier method were used for statistical analysis.

RESULTS

The aberrant expression of hsa_circ_0006010 and hsa_circ_0002903 during CML progression could serve as valuable biomarkers for differentiating CML-AP/BP patients from CMP-CP patients or HCs. In addition, the expression levels of hsa_circ_0006010 and hsa_circ_0002903 were significantly associated with the clinical features of CML patients but were not directly related to the four scoring systems. Furthermore, survival analysis revealed that high hsa_circ_0006010 expression and low hsa_circ_0002903 expression indicated poor progression-free survival (PFS) in CML patients. Finally, PB hsa_circ_0006010 and hsa_circ_0002903 expression at diagnosis may also serve as disease progression surveillance markers for CML patients but were not correlated with PB BCR-ABL1/ABL1IS.

CONCLUSIONS

Our study demonstrated that PB levels of hsa_circ_0006010 and hsa_circ_0002903 may serve as novel diagnostic, surveillance, and prognostic biomarkers for CML disease progression and may contribute to assisting in the diagnosis of CML patients at risk for progression and accurate management of advanced CML patients.

Integrating amino acids into Bcr-Abl inhibitors: design, synthesis, biological evaluation, and in silico studies

Bcr-Abl is successfully applied to drug discovery as a CML therapeutic target, but point mutation resistance has become a major challenge in the clinical treatment of CML. Our previous studies have shown that the introduction of amino acids as flexible linkers and heterocyclic structures as HBMs can achieve potent inhibition of Bcr-AblT315I. In continuation of these studies, we further enriched the linker types by developing a library of compounds with tert-leucine or serine as a linker. Biological results showed that these compounds exhibited enhanced inhibition against Bcr-AblWT and Bcr-AblT315I kinases as well as improved antiproliferative activity in leukemia cell assays compared to previously disclosed compounds. In particular, compounds TL8, TL10, BS4, BS10, SR5 and SR11 exhibited potent inhibitory activities against Ba/F3 cells bearing a T315I mutant. Additionally, compounds TL8, BS4 and SR5 effectively induced K562 cell apoptosis, arrested the cell cycle at the S or G2/M phase, and inhibited the phosphorylation of Bcr-Abl and STAT5 in a dose-dependent manner. Docking studies verified the rationality of tert-leucine or serine as a flexible linker and indicated that phenylpyridine with an amide side chain favored the potency of these inhibitors. Moreover, ADME prediction suggested that the tested compounds had a favorable safety profile. Thus, tert-leucine or serine can be used as a promising class of flexible linkers for Bcr-Abl inhibitors with heterocyclic structures as HBMs, and compounds BS4, SR5, and especially TL8, can be used as starting points for further optimization.

Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology

Leonurine is an alkaloid unique to the Leonurus genus, which has many biological activities, such as uterine contraction, anti-inflammation, anti-oxidation, regulation of cell apoptosis, anti-tumor, angiogenesis, anti-platelet aggregation, and inhibition of vasoconstriction. This paper summarizes the extraction methods, synthetic pathways, biosynthetic mechanisms, pharmacokinetic properties, pharmacological effects in various diseases, toxicology, and clinical trials of leonurine. To facilitate a successful transition into clinical application, intensified efforts are required in several key areas: structural modifications of leonurine to optimize its properties, comprehensive pharmacokinetic assessments to understand its behavior within the body, thorough mechanistic studies to elucidate how it works at the molecular level, rigorous safety evaluations and toxicological investigations to ensure patient wellbeing, and meticulously conducted clinical trials to validate its efficacy and safety profile.

Changes in chronic myeloid leukemia treatment modalities and outcomes after introduction of second-generation tyrosine kinase inhibitors as first-line therapy: a multi-institutional retrospective study by the CML Cooperative Study Group

This study investigated changes in treatment modalities and outcomes of chronic myeloid leukemia in the chronic phase (CP-CML) after the approval of second-generation tyrosine kinase inhibitors (2G-TKIs) for first-line therapy. Patients were grouped into those who underwent TKI therapy up to December 2010 (imatinib era group, n = 185) and after January 2011 (2G-TKI era group, n = 425). All patients in the imatinib era group were initially treated with imatinib, whereas patients in the 2G-TKI era group were mostly treated with dasatinib (55%) or nilotinib (36%). However, outcomes including progression-free survival, overall survival, and CML-related death (CRD) did not differ significantly between groups. When stratified by risk scores, the prognostic performance of the ELTS score was superior to that of the Sokal score. Even though both scoring systems predicted CRD in the imatinib era, only the ELTS score predicted CRD in the 2G-TKI era. Notably, the outcome of patients classified as high-risk by ELTS score was more favorable in the 2G-TKI era group than in the imatinib era group. Thus, expanding treatment options may have improved patient outcomes in CP-CML, particularly in patients classified as high-risk by ELTS score.

Leukemic Stem Cells and Hematological Malignancies

The association between leukemic stem cells (LSCs) and leukemia development has been widely established in the context of genetic alterations, epigenetic pathways, and signaling pathway regulation. Hematopoietic stem cells are at the top of the bone marrow hierarchy and can self-renew and progressively generate blood and immune cells. The microenvironment, niche cells, and complex signaling pathways that regulate them acquire genetic mutations and epigenetic alterations due to aging, a chronic inflammatory environment, stress, and cancer, resulting in hematopoietic stem cell dysregulation and the production of abnormal blood and immune cells, leading to hematological malignancies and blood cancer. Cells that acquire these mutations grow at a faster rate than other cells and induce clone expansion. Excessive growth leads to the development of blood cancers. Standard therapy targets blast cells, which proliferate rapidly; however, LSCs that can induce disease recurrence remain after treatment, leading to recurrence and poor prognosis. To overcome these limitations, researchers have focused on the characteristics and signaling systems of LSCs and therapies that target them to block LSCs. This review aims to provide a comprehensive understanding of the types of hematopoietic malignancies, the characteristics of leukemic stem cells that cause them, the mechanisms by which these cells acquire chemotherapy resistance, and the therapies targeting these mechanisms.

RAPSYN-mediated neddylation of BCR-ABL alternatively determines the fate of Philadelphia chromosome-positive leukemia

Philadelphia chromosome-positive (Ph+) leukemia is a fatal hematological malignancy. Although standard treatments with tyrosine kinase inhibitors (TKIs) have achieved remarkable success in prolonging patient survival, intolerance, relapse, and TKI resistance remain serious issues for patients with Ph+ leukemia. Here, we report a new leukemogenic process in which RAPSYN and BCR-ABL co-occur in Ph+ leukemia, and RAPSYN mediates the neddylation of BCR-ABL. Consequently, neddylated BCR-ABL enhances the stability by competing its c-CBL-mediated degradation. Furthermore, SRC phosphorylates RAPSYN to activate its NEDD8 E3 ligase activity, promoting BCR-ABL stabilization and disease progression. Moreover, in contrast to in vivo ineffectiveness of PROTAC-based degraders, depletion of RAPSYN expression, or its ligase activity decreased BCR-ABL stability and, in turn, inhibited tumor formation and growth. Collectively, these findings represent an alternative to tyrosine kinase activity for the oncoprotein and leukemogenic cells and generate a rationale of targeting RAPSYN-mediated BCR-ABL neddylation for the treatment of Ph+ leukemia.

Analytical validation of the DropXpert S6 system for diagnosis of chronic myelocytic leukemia

Digital PCR is a powerful method for absolute nucleic acid quantification and is widely used in the absolute quantification of viral copy numbers, tumor marker detection, and prenatal diagnosis. However, for most of the existing droplet-based dPCR systems, the droplet generation, PCR reaction, and droplet detection are performed separately using different instruments. Making digital PCR both easy to use and practical by integrating the qPCR workflow into a superior all-in-one walkaway solution is one of the core ideas. A new innovative and integrated digital droplet PCR platform was developed that utilizes cutting-edge microfluidics to integrate dPCR workflows onto a single consumable chip. This makes previously complex workflows fast and simple; the whole process of droplet generation, PCR amplification, and droplet detection is completed on one chip, which meets the clinical requirement of "sample in, result out". It provides high multiplexing capabilities and strong sensitivity while all measurements were within the 95% confidence interval. This study is the first validation of the DropXpert S6 system and focuses primarily on verifying its reliability, repeatability, and consistency. In addition, the accuracy, detection limit, linearity, and precision of the system were evaluated after sample collection. Among them, the accuracy assessment by calculating the absolute bias of each target gene yielded a range from -0.1 to 0.08, all within ±0.5 logarithmic orders of magnitude; the LOB for the assay was set at 0, and the LoD value calculated using probit curves is MR4.7 (0.002%); the linearity evaluation showed that the R2 value of the BCR-ABL was 0.9996, and the R2 value of the ABL metrics calculated using the ERM standard was 0.9999; and the precision evaluation showed that all samples had a CV of less than 4% for intra-day, inter-day, and inter-instrument variation. The CV of inter-batch variation was less than 7%. The total CV was less than 5%. The results of the study demonstrate that dd-PCR can be applied to molecular detection and the clinical evaluation of CML patients and provide more precise personal treatment guidance, and its reproducibility predicts the future development of a wide range of clinical applications.

Lycorine attenuated proliferation and induced apoptosis on imatinib-resistant K562 cell by inhibiting autophagy

BACKGROUND

Tyrosine kinase inhibitor (TKI) resistance is a significant factor exacerbating the burden on chronic myeloid leukemia (CML) patients and impacting clinical efficacy. The main goal is to offer new insights into overcoming drug resistance in treating CML.

METHODS

Imatinib (IM) resistant K562/IM cells were generated using gradient induction. Responses to IM, lycorine, and autophagy modulators were assessed using CCK-8. Protein expression of Beclin-1, Atg5, LC3, Caspase-3, P62, Bax, Bcl-2, and P-gp was detected using Western blot. Lycorine-induced apoptosis and cell cycle changes were evaluated through flow cytometry, while autophagy alterations were detected using monodansylcadaverine (MDC) staining. In the K562/IM mice model, non-obese diabetic severe combined immunodeficent (NOD-SCID) mice were subcutaneously inoculated with K562/IM cells. After 17 days of lycorine injection, assessments included tumor size, hematoxylin-eosin (HE) staining, and Ki67 expression.

RESULTS

After 72 h of IM treatment, K562/IM cells showed a 55.86-fold increase in drug resistance compared to K562 cells. Lycorine treatment for 24 h inhibited cell proliferation and induced G0/G1 phase cell cycle arrest and apoptosis in both K562 and K562/IM cells. MDC staining indicated reduced autophagy in K562/IM cells, mitigated by lycorine. In vivo experiments demonstrated reduced tumor size and Ki67 proliferation index in the lycorine treatment group (K562+L, K562/IM+L) compared to the control group, particularly in the drug-resistant group. However, no significant change in Ki67 was observed in the K562 group after lycorine treatment.

CONCLUSION

In summary, K562/IM cells displayed heightened autophagy levels compared to K562 cells. Lycorine effectively impeded the proliferation of K562/IM cells through diverse mechanisms, including reduced autophagy, enhanced apoptosis, and induced cell cycle arrest.

The FABD domain is critical for the oncogenicity of BCR/ABL in chronic myeloid leukaemia

BACKGROUND

Abnormally expressed BCR/ABL protein serves as the basis for the development of chronic myeloid leukaemia (CML). The F-actin binding domain (FABD), which is a crucial region of the BCR/ABL fusion protein, is also located at the carboxyl end of the c-ABL protein and regulates the kinase activity of c-ABL. However, the precise function of this domain in BCR/ABL remains uncertain.

METHODS

The FABD-deficient adenovirus vectors Ad-BCR/ABL△FABD, wild-type Ad-BCR/ABL and the control vector Adtrack were constructed, and 32D cells were infected with these adenoviruses separately. The effects of FABD deletion on the proliferation and apoptosis of 32D cells were evaluated by a CCK-8 assay, colony formation assay, flow cytometry and DAPI staining. The levels of phosphorylated BCR/ABL, p73, and their downstream signalling molecules were detected by western blot. The intracellular localization and interaction of BCR/ABL with the cytoskeleton-related protein F-actin were identified by immunofluorescence and co-IP. The effect of FABD deletion on BCR/ABL carcinogenesis in vivo was explored in CML-like mouse models. The degree of leukaemic cell infiltration was observed by Wright‒Giemsa staining and haematoxylin and eosin (HE) staining.

RESULTS

We report that the loss of FABD weakened the proliferation-promoting ability of BCR/ABL, accompanied by the downregulation of BCR/ABL downstream signals. Moreover, the deletion of FABD resulted in a change in the localization of BCR/ABL from the cytoplasm to the nucleus, accompanied by an increase in cell apoptosis due to the upregulation of p73 and its downstream proapoptotic factors. Furthermore, we discovered that the absence of FABD alleviated leukaemic cell infiltration induced by BCR/ABL in mice.

CONCLUSIONS

These findings reveal that the deletion of FABD diminished the carcinogenic potential of BCR/ABL both in vitro and in vivo. This study provides further insight into the function of the FABD domain in BCR/ABL.

Tyrosine Kinase Inhibitor Discontinuation in Chronic Myeloid Leukemia: Strategies to Optimize Success and New Directions

PURPOSE OF REVIEW

The discovery that patients suffering from chronic myeloid leukemia who obtain deep and long-lasting molecular responses upon treatment with tyrosine kinase inhibitors may maintain their disease silent for many years after therapy discontinuation launched the era of treatment-free remission as a key management goal in clinical practice. The purpose of this review on treatment-free remission is to discuss clinical advances, highlight knowledge gaps, and describe areas of research.

RECENT FINDINGS

Patients in treatment-free remission are a minority, and it is believed that some may still retain a reservoir of leukemic stem cells; thus, whether they can be considered as truly cured is uncertain. Strengthening BCR::ABL1 inhibition increases deep molecular responses but is not sufficient to improve treatment-free remission, and we lack biomarkers to identify and specifically target residual cells with aggressive potential. Another level of complexity resides in the intra- and inter-patient clonal heterogeneity of minimal residual disease and characteristics of the bone marrow environment. Finding determinants of deep molecular responses achievement and elucidating varying biological mechanisms enabling either post-tyrosine kinase inhibitor chronic myeloid leukemia control or relapse may help develop innovative and safe therapies. In the light of the increasing prevalence of CML, targeting the residual leukemic stem cell pool is thought to be the key.

PROteolysis-Targeting Chimeras (PROTACs) in leukemia: overview and future perspectives

Leukemia is a heterogeneous group of life-threatening malignant disorders of the hematopoietic system. Immunotherapy, radiotherapy, stem cell transplantation, targeted therapy, and chemotherapy are among the approved leukemia treatments. Unfortunately, therapeutic resistance, side effects, relapses, and long-term sequelae occur in a significant proportion of patients and severely compromise the treatment efficacy. The development of novel approaches to improve outcomes is therefore an unmet need. Recently, novel leukemia drug discovery strategies, including targeted protein degradation, have shown potential to advance the field of personalized medicine for leukemia patients. Specifically, PROteolysis-TArgeting Chimeras (PROTACs) are revolutionary compounds that allow the selective degradation of a protein by the ubiquitin-proteasome system. Developed against a wide range of cancer targets, they show promising potential in overcoming many of the drawbacks associated with conventional therapies. Following the exponential growth of antileukemic PROTACs, this article reviews PROTAC-mediated degradation of leukemia-associated targets. Chemical structures, in vitro and in vivo activities, pharmacokinetics, pharmacodynamics, and clinical trials of PROTACs are critically discussed. Furthermore, advantages, challenges, and future perspectives of PROTACs in leukemia are covered, in order to understand the potential that these novel compounds may have as future drugs for leukemia treatment.

Recent Advances in Material Technology for Leukemia Treatments

Leukemia is a widespread hematological malignancy characterized by an elevated white blood cell count in both the blood and the bone marrow. Despite notable advancements in leukemia intervention in the clinic, a large proportion of patients, especially acute leukemia patients, fail to achieve long-term remission or complete remission following treatment. Therefore, leukemia therapy necessitates optimization to meet the treatment requirements. In recent years, a multitude of materials have undergone rigorous study to serve as delivery vectors or direct intervention agents to bolster the effectiveness of leukemia therapy. These materials include liposomes, protein-based materials, polymeric materials, cell-derived materials, and inorganic materials. They possess unique characteristics and are applied in a broad array of therapeutic modalities, including chemotherapy, gene therapy, immunotherapy, radiotherapy, hematopoietic stem cell transplantation, and other evolving treatments. Here, an overview of these materials is presented, describing their physicochemical properties, their role in leukemia treatment, and the challenges they face in the context of clinical translation. This review inspires researchers to further develop various materials that can be used to augment the efficacy of multiple therapeutic modalities for novel applications in leukemia treatment.

Current Status and Management of Chronic Myeloid Leukemia in the Gulf Region: Survey Results and Expert Opinion

Studies on chronic myeloid leukemia (CML) in the Gulf region are scarce, consisting of a survey and expert meeting that included 15 experts in 2023 which discussed CML diagnosis, testing, treatment objectives, toxicities, and discontinuation in the Gulf region. Most patients were reported to be in first-line therapy, and the most common treatments were imatinib/imatinib generic in first-line and dasatinib in second- and third-lines. Mutation analysis was not reported to be routinely performed at the time of diagnosis but rather in case of progression to accelerated/blast phase or any sign of loss of response. While all participants were aware that BCR-ABL should be monitored every three months during the first year of treatment, 10% reported monitoring BCR-ABL every six months in practice due to test cost and lab capability. The most important first-line therapy objective was "achievement of major molecular response" (MMR) in younger patients and "overall survival" in older ones. The most important treatment objectives were "MMR" and "early molecular response followed by prolongation of overall survival" in the short term and "treatment-free remission" in the long term. The current practices in CML in the Gulf region appear to be similar to global figures.

Influence of genetic polymorphisms on imatinib concentration and therapeutic response in patients with chronic-phase chronic myeloid leukemia

BACKGROUND

Diminished bioavailability of imatinib in leukemic cells contributes to poor clinical response. We examined the impact of genetic polymorphisms of imatinib on the pharmacokinetics and clinical response in 190 patients with chronic myeloid leukaemia (CML).

METHODS

Single nucleotide polymorphisms were genotyped using pyrophosphate sequencing. Plasma trough levels of imatinib were measured using liquid chromatography-tandem mass spectrometry.

RESULTS

Patients carrying the TT genotype for ABCB1 (rs1045642, rs2032582, and rs1128503), GG genotype for CYP3A5-rs776746 and AA genotype for ABCG2-rs2231142 polymorphisms showed higher concentration of imatinib. Patients with T allele for ABCB1 (rs1045642, rs2032582, and rs1128503), A allele for ABCG2-rs2231142, and G allele for CYP3A5-rs776746 polymorphisms showed better cytogenetic response and molecular response. In multivariate analysis, carriers of the CYP3A5-rs776746 G allele exhibited higher rates of complete cytogenetic response (CCyR) and major molecular response (MMR). Similarly, patients with the T allele of ABCB1-rs1045642 and rs1128503 demonstrated significantly increased CCyR rates. Patients with the A allele of ABCG2-rs2231142 were associated with higher MMR rates. The AA genotype for CYP3A5-rs776746, and the CC genotype for ABCB1-rs104562, and rs1128503 polymorphisms were associated with a higher risk of imatinib failure. Patients with the G allele for CYP3A5-rs776746 exhibited a higher incidence of anemia, and T allele for ABCB1-rs2032582 demonstrated an increased incidence of diarrhea.

CONCLUSIONS

Genotyping of ABCB1, ABCG2, and CYP3A5 genes may be considered in the management of patients with CML to tailor therapy and optimize clinical outcomes.

Long non-coding RNA PXN-AS1 promotes glutamine synthetase-mediated chronic myeloid leukemia BCR::ABL1-independent resistance to Imatinib via cell cycle signaling pathway

BACKGROUND

Chronic myeloid leukemia (CML) is a common hematological malignancy, and tyrosine kinase inhibitors (TKIs) represent the primary therapeutic approach for CML. Activation of metabolism signaling pathway has been connected with BCR::ABL1-independent TKIs resistance in CML cells. However, the specific mechanism by which metabolism signaling mediates this drug resistance remains unclear. Here, we identified one relationship between glutamine synthetase (GS) and BCR::ABL1-independent Imatinib resistance in CML cells.

METHODS

GS and PXN-AS1 in bone marrow samples of CML patients with Imatinib resistance (IR) were screened and detected by whole transcriptome sequencing. GS expression was upregulated using LVs and blocked using shRNAs respectively, then GS expression, Gln content, and cell cycle progression were respectively tested. The CML IR mice model were established by tail vein injection, prognosis of CML IR mice model were evaluated by Kaplan-Meier analysis, the ratio of spleen/body weight, HE staining, and IHC. PXN-AS1 level was blocked using shRNAs, and the effects of PXN-AS1 on CML IR cells in vitro and in vivo were tested the same as GS. Several RNA-RNA tools were used to predict the potential target microRNAs binding to both GS and PXN-AS1. RNA mimics and RNA inhibitors were used to explore the mechanism through which PXN-AS1 regulates miR-635 or miR-635 regulates GS.

RESULTS

GS was highly expressed in the bone marrow samples of CML patients with Imatinib resistance. In addition, the lncRNA PXN-AS1 was found to mediate GS expression and disorder cell cycle in CML IR cells via mTOR signaling pathway. PXN-AS1 regulated GS expression by binding to miR-635. Additionally, knockdown of PXN-AS1 attenuated BCR::ABL1-independent Imatinib resistance in CML cells via PXN-AS1/miR-635/GS/Gln/mTOR signaling pathway.

CONCLUSIONS

Thus, PXN-AS1 promotes GS-mediated BCR::ABL1-independent Imatinib resistance in CML cells via cell cycle signaling pathway.

Osteosarcoma Arising as a Secondary Malignancy following Treatment for Hematologic Cancer: A Report of 33 Affected Patients from the Cooperative Osteosarcoma Study Group (COSS)

PURPOSE

Osteosarcoma may arise as a secondary cancer following leukemias or lymphomas. We intended to increase the knowledge about such rare events.

PATIENTS AND METHODS

We searched the Cooperative Osteosarcoma Study Group's database for individuals who developed their osteosarcoma following a previous hematological malignancy. The presentation and treatment of both malignancies was investigated, and additional neoplasms were noted. Outcomes after osteosarcoma were analyzed and potential prognostic factors were searched for.

RESULTS

A total of 33 eligible patients were identified (male: 23, female: 10; median age: 12.9 years at diagnosis of hematological cancer; 20 lymphomas, 13 leukemias). A cancer predisposition syndrome was evident in one patient only. The hematological cancers had been treated by radiotherapy in 28 (1 unknown) and chemotherapy in 26 cases, including bone-marrow transplantation in 9. The secondary bone sarcomas (high-grade central 27, periosteal 2, extra-osseous 2, undifferentiated pleomorphic sarcoma of bone 2) arose after a median lag-time of 9.4 years, when patients were a median of 19.1 years old. Tumors were considered radiation-related in 26 cases (1 unknown). Osteosarcoma-sites were in the extremities (19), trunk (12), or head and neck (2). Metastases at diagnosis affected eight patients. Information on osteosarcoma therapy was available for 31 cases. All of these received chemotherapy. Local therapy involved surgery in 27 patients, with a good response reported for 9/18 eligible patients. Local radiotherapy was given to three patients. The median follow-up was 3.9 (0.3-12.0) years after bone tumor diagnosis. During this period, 21 patients had developed events as defined, and 15 had died, resulting in 5-year event-free and overall survival rates of 40% (standard error: 9%) and 56% (10%), respectively. There were multiple instances of additional neoplasms. Several factors were found to be of prognostic value (p < 0.05) for event-free (osteosarcoma site in the extremities) or overall (achievement of a surgical osteosarcoma-remission, receiving chemotherapy for the hematologic malignancy) survival.

CONCLUSIONS

We were able to prove radiation therapy for hematological malignancies to be the predominant risk factor for later osteosarcomas. A resulting overrepresentation of axial and a tendency towards additional neoplasms affects prognosis. Still, selected patients may become long-term survivors with appropriate therapies, which is an argument against therapeutic negligence.

Chronic myeloid leukaemia: Biology and therapy

Chronic myeloid leukaemia (CML) is caused by BCR::ABL1. Tyrosine kinase-inhibitors (TKIs) are the initial therapy. Several organizations have reported milestones to evaluate response to initial TKI-therapy and suggest when a change of TKI should be considered. Achieving treatment-free remission (TFR) is increasingly recognized as the optimal therapy goal. Which TKI is the best initial therapy for which persons and what depth and duration of molecular remission is needed to achieve TFR are controversial. In this review we discuss these issues and suggest future research directions.

The molecular signature of BCR::ABLP210 and BCR::ABLT315I in a Drosophila melanogaster chronic myeloid leukemia model

Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder resulting from a balanced translocation leading to BCR::ABL1 oncogene with increased tyrosine kinase activity. Despite the advancements in the development of tyrosine kinase inhibitors (TKIs), the T315I gatekeeper point mutation in the BCR::ABL1 gene remains a challenge. We have previously reported in a Drosophila CML model an increased hemocyte count and disruption in sessile hemocyte patterns upon expression of BCR::ABL1p210 and BCR::ABL1T315I in the hemolymph. In this study, we performed RNA sequencing to determine if there is a distinct gene expression that distinguishes BCR::ABL1p210 and BCR::ABL1T315I. We identified six genes that were consistently upregulated in the fly CML model and validated in adult and pediatric CML patients and in a mouse cell line expressing BCR::ABL1T315I. This study provides a comprehensive analysis of gene signatures in BCR::ABL1p210 and BCR::ABL1T315I, laying the groundwork for targeted investigations into the role of these genes in CML pathogenesis.

Oral arsenic plus imatinib versus imatinib solely for newly diagnosed chronic myeloid leukemia: a randomized phase 3 trial with 5-year outcomes

PURPOSE

The synergistic effects of combining arsenic compounds with imatinib against chronic myeloid leukemia (CML) have been established using in vitro data. We conducted a clinical trial to compare the efficacy of the arsenic realgar-indigo naturalis formula (RIF) plus imatinib with that of imatinib monotherapy in patients with newly diagnosed chronic phase CML (CP-CML).

METHODS

In this multicenter, randomized, double-blind, phase 3 trial, 191 outpatients with newly diagnosed CP-CML were randomly assigned to receive oral RIF plus imatinib (n = 96) or placebo plus imatinib (n = 95). The primary end point was the major molecular response (MMR) at 6 months. Secondary end points include molecular response 4 (MR4), molecular response 4.5 (MR4.5), progression-free survival (PFS), overall survival (OS), and adverse events.

RESULTS

The median follow-up duration was 51 months. Due to the COVID-19 pandemic, the recruitment to this study had to be terminated early, on May 28, 2020. The rates of MMR had no significant statistical difference between combination and imatinib arms at 6 months and any other time during the trial. MR4 rates were similar in both arms. However, the 12-month cumulative rates of MR4.5 in the combination and imatinib arms were 20.8% and 10.5%, respectively (p = 0.043). In core treatment since the 2-year analysis, the frequency of MR4.5 was 55.6% in the combination arm and 38.6% in the imatinib arm (p = 0.063). PFS and OS were similar at five years. The safety profiles were similar and serious adverse events were uncommon in both groups.

CONCLUSION

The results of imatinib plus RIF as a first-line treatment of CP-CML compared with imatinib might be more effective for achieving a deeper molecular response (Chinadrugtrials number, CTR20170221).

Loss of the vitamin D receptor triggers senescence in chronic myeloid leukemia via DDIT4-mediated DNA damage

Chronic myeloid leukemia (CML) is a hematopoietic malignancy driven by the fusion gene BCR::ABL1. Drug resistance to tyrosine kinase inhibitors (TKIs), due to BCR::ABL1 mutations and residual leukemia stem cells (LSCs), remains a major challenge in CML treatment. Here, we revealed the requirement of the vitamin D receptor (VDR) in the progression of CML. VDR was upregulated by BCR::ABL1 and highly expressed in CML cells. Interestingly, VDR knockdown inhibited the proliferation of CML cells driven by both BCR::ABL1 and TKI-resistant BCR::ABL1 mutations. Mechanistically, VDR transcriptionally regulated DDIT4 expression; reduced DDIT4 levels upon VDR knockdown triggered DNA damage and senescence via p53 signaling activation in CML cells. Furthermore, VDR deficiency not only suppressed tumor burden and progression in primary CML mice but also reduced the self-renewal capacity of CML-LSCs. Together, our study demonstrated that targeting VDR is a promising strategy to overcome TKI resistance and eradicate LSCs in CML.

Prognostic Impact of Bone Marrow Fibrosis and Effects of Tyrosine Kinase Inhibitors on Bone Marrow Fibrosis in Chronic Myeloid Leukemia

BACKGROUND

Myelofibrosis is reported in around 40% of newly diagnosed chronic myeloid leukemia (CML) patients and have an important role in the pathobiology and prognosis of CML. This retrospective study aimed to evaluate the effects of bone marrow (BM) fibrosis on disease prognosis and the effects of specific tyrosine-kinase inhibitors (TKIs) on BM fibrosis in CML patients.

METHODS

The study included 96 patients (>18 years) diagnosed with chronic phase (CP) CML. The clinical and demographic information were collected from the medical files. Post-treatment BM aspirate and core biopsy samples were analyzed for the presence of fibrosis and dysplasia.

RESULTS

The mean age of the study patients was 52.69 years; 47.9% of the patients were female. At the onset, 53 (63.1%) patients had BM fibrosis. The difference in the overall survival of the patients with respect to BM fibrosis grades was significant (p = .001). Within the BM fibrosis grade groups, there were significant differences between grade 0 vs. grade 2, grade 0 vs. grade 3, and grade 1 vs. grade 3 (p = .005, p = .002, and p = .003 respectively) There was no significant association between the presence of BM fibrosis at the onset and not responding to first-line therapy (p = .724). Moreover, no significant association was found between the presence of BM fibrosis at the onset and molecular (p = .623) or cytogenetic response (p = .535) to first-line therapy. Additionally, the association between the type of second-line and third-line therapy and molecular response (p = .773 and p = .424, respectively) or cytogenetic response (p = .298 and p = .641) was not significant.

CONCLUSION

Although BM fibrosis seems to be a crucial complication of CML with a poor prognosis, it can be reversed via TKI treatment which may result in improved survival. It might be considered to check the BM for this complication on a regular basis during therapies to test its prognostic influence in CML patients in prospective controlled trials. Further studies focused on this issue are required to utilize BM fibrosis as a candidate prognostic factor.

State-transition modeling of blood transcriptome predicts disease evolution and treatment response in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is initiated and maintained by BCR::ABL which is clinically targeted using tyrosine kinase inhibitors (TKIs). TKIs can induce long-term remission but are also not curative. Thus, CML is an ideal system to test our hypothesis that transcriptome-based state-transition models accurately predict cancer evolution and treatment response. We collected time-sequential blood samples from tetracycline-off (Tet-Off) BCR::ABL-inducible transgenic mice and wild-type controls. From the transcriptome, we constructed a CML state-space and a three-well leukemogenic potential landscape. The potential's stable critical points defined observable disease states. Early states were characterized by anti-CML genes opposing leukemia; late states were characterized by pro-CML genes. Genes with expression patterns shaped similarly to the potential landscape were identified as drivers of disease transition. Re-introduction of tetracycline to silence the BCR::ABL gene returned diseased mice transcriptomes to a near healthy state, without reaching it, suggesting parts of the transition are irreversible. TKI only reverted the transcriptome to an intermediate disease state, without approaching a state of health; disease relapse occurred soon after treatment. Using only the earliest time-point as initial conditions, our state-transition models accurately predicted both disease progression and treatment response, supporting this as a potentially valuable approach to time clinical intervention, before phenotypic changes become detectable.

The potential role of hydrogen sulfide in cancer cell apoptosis

For a long time, hydrogen sulfide (H2S) has been considered a toxic compound, but recent studies have found that H2S is the third gaseous signaling molecule which plays a vital role in physiological and pathological conditions. Currently, a large number of studies have shown that H2S mediates apoptosis through multiple signaling pathways to participate in cancer occurrence and development, for example, PI3K/Akt/mTOR and MAPK signaling pathways. Therefore, the regulation of the production and metabolism of H2S to mediate the apoptotic process of cancer cells may improve the effectiveness of cancer treatment. In this review, the role and mechanism of H2S in cancer cell apoptosis in mammals are summarized.

Long-Term Follow-Up in Patients With Chronic Myeloid Leukemia Treated With Ponatinib in a Real-World Cohort: Safety and Efficacy Analysis

BACKGROUND

Ponatinib is a third-generation tyrosine-kinase inhibitor (TKI), indicated in patients with chronic phase (CP), accelerated phase (AP), or blast phase (BP) chronic myeloid leukemia (CML), who are resistant or intolerant to ≥2 prior TKIs, patients for whom subsequent treatment with imatinib is not appropriate, and patients who have a T315I mutation.

PATIENTS AND METHODS

We aimed to evaluate outcomes of ponatinib treatment, including safety, with focus on cardiovascular toxicity, in real-world patients from Argentina. Data from patients with CP CML treated with ponatinib was retrospectively retrieved from 2013 to 2023 in 7 centers.

RESULTS

Seventy-two patients were included (median age: 44 years; male: 55.5%; T315I mutation: 32%: median treatment duration: 36 months. At baseline, 57 patients (79%) had a breakpoint cluster region-Abelson (BCR::ABL1) transcript level >10% on the international reporting scale (BCR::ABL1 IS). A molecular response (MR, BCR::ABL1 (IS) <1%) was achieved at 12 months in 51.6% of evaluable patients; 57% maintained MR at last follow-up. Overall, 43% and 25% maintained major MR (MMR) or deep MR (DMR) (MR4.0-MR5.0), respectively at last follow-up. Twelve (16.6%) ponatinib-resistant patients were rescued with allogeneic hematopoietic stem cell transplantation. The estimated 2-year progression-free survival (PFS) was 84%. Ponatinib dose was reduced during treatment in 22 patients; nevertheless, MMR was maintained in 50% of these patients. Severe arterial occlusive events (AOE) were reported in 10.9% of patients after a median treatment of 5 months.

CONCLUSION

CV toxicity was consistent with clinical trials and other real-world registries. Older age, hypercholesterolemia and a SCORE risk >2% were significantly associated with higher risk of AOEs. Controlling CV risk factors and reducing doses at optimal time points may help to optimize ponatinib use in daily practice.

Clinical pharmacokinetics and drug-drug interactions of tyrosine-kinase inhibitors in chronic myeloid leukemia: A clinical perspective

In the past decade, numerous tyrosine kinase inhibitors (TKIs) have been introduced in the treatment of chronic myeloid leukemia. Given the significant interpatient variability in TKIs pharmacokinetics, potential drug-drug interactions (DDIs) can greatly impact patient therapy. This review aims to discuss the pharmacokinetic characteristics of TKIs, specifically focusing on their absorption, distribution, metabolism, and excretion profiles. Additionally, it provides a comprehensive overview of the utilization of TKIs in special populations such as the elderly, children, and patients with liver or kidney dysfunction. We also highlight known or suspected DDIs between TKIs and other drugs, highlighting various clinically relevant interactions. Moreover, specific recommendations are provided to guide haemato-oncologists, oncologists, and clinical pharmacists in managing DDIs during TKI treatment in daily clinical practice.

Pharmacovigilance study of BCR-ABL1 tyrosine kinase inhibitors: a safety analysis of the FDA adverse event reporting system

BACKGROUND

With the increased use of BCR-ABL1 tyrosine kinase inhibitors (TKIs) in cancer patients, adverse events (AEs) have garnered considerable interest. We conducted this pharmacovigilance study to evaluate the AEs of BCR-ABL1 TKIs in cancer patients using the Food and Drug Administration Adverse Event Reporting System (FAERS) database.

METHODS

To query AE reports from the FAERS database, we used OpenVigil 2.1. Descriptive analysis was then employed to describe the characteristics of TKIs-associated AE reports. We also utilized the disproportionality analysis to detect safety signals by calculating the proportional reporting ratio (PRR) and reporting odds ratios (ROR).

RESULTS

From the FAERS database, a total of 85,989 AE reports were retrieved, with 3,080 significant AE signals identified. Specifically, imatinib, nilotinib, dasatinib, bosutinib, and ponatinib had significant AE signals of 1,058, 813, 232, 186, and 791, respectively. These significant signals were further categorized into 26 system organ classes (SOCs). The AE signals of imatinib and ponatinib were primarily associated with general disorders and administration site conditions. On the other hand, nilotinib, dasatinib, and bosutinib were mainly linked to investigations, respiratory, thoracic and mediastinal disorders, and gastrointestinal disorders, respectively. Notably, new signals of 245, 278, 47, 55, and 253 were observed in imatinib, nilotinib, dasatinib, bosutinib, and ponatinib, respectively.

CONCLUSIONS

The results of this study demonstrated that AE signals differ among the five BCR-ABL1 TKIs. Furthermore, each BCR-ABL1 TKI displayed several new signals. These findings provide valuable information for clinicians aiming to reduce the risk of AEs during BCR-ABL1 TKI treatment.

Chemoproteomics Reveals Glaucocalyxin A Induces Mitochondria-Dependent Apoptosis of Leukemia Cells via Covalently Binding to VDAC1

Chronic myelogenous leukemia (CML) that is resistant to tyrosine kinase inhibitors is one of the deadliest hematologic malignancies, and the T315I mutation in the breakpoint cluster region-Abelson (BCR-ABL) kinase domain is the most prominent point mutation responsible for imatinib resistance in CML. Glaucocalyxin A (GLA), a natural bioactive product derived from the Rabdosia rubescens plant, has strong anticancer activity. In this study, the effect and molecular mechanism of GLA on imatinib-sensitive and imatinib-resistant CML cells harboring T315I mutation via a combined deconvolution strategy of chemoproteomics and label-free proteomics is investigated. The data demonstrated that GLA restrains proliferation and induces mitochondria-dependent apoptosis in both imatinib-sensitive and resistant CML cells. GLA covalently binds to the cysteine residues of mitochondrial voltage-dependent anion channels (VDACs), resulting in mitochondrial damage and overflow of intracellular apoptotic factors, eventually leading to apoptosis. In addition, the combination of GLA with elastin, a mitochondrial channel VDAC2/3 inhibitor, enhances mitochondria-dependent apoptosis in imatinib-sensitive and -resistant CML cells, representing a promising therapeutic approach for leukemia treatment. Taken together, the results show that GLA induces mitochondria-dependent apoptosis via covalently targeting VDACs in CML cells. GLA may thus be a candidate compound for the treatment of leukemia.

Properties of FDA-approved small molecule protein kinase inhibitors: A 2024 update

Owing to the dysregulation of protein kinase activity in many diseases including cancer, this enzyme family has become one of the most important drug targets in the 21st century. There are 80 FDA-approved therapeutic agents that target about two dozen different protein kinases and seven of these drugs were approved in 2023. Of the approved drugs, thirteen target protein-serine/threonine protein kinases, four are directed against dual specificity protein kinases (MEK1/2), twenty block nonreceptor protein-tyrosine kinases, and 43 inhibit receptor protein-tyrosine kinases. The data indicate that 69 of these drugs are prescribed for the treatment of neoplasms. Six drugs (abrocitinib, baricitinib, deucravacitinib, ritlecitinib, tofacitinib, upadacitinib) are used for the treatment of inflammatory diseases (atopic dermatitis, rheumatoid arthritis, psoriasis, alopecia areata, and ulcerative colitis). Of the 80 approved drugs, nearly two dozen are used in the treatment of multiple diseases. The following seven drugs received FDA approval in 2023: capivasertib (HER2-positive breast cancer), fruquintinib (metastatic colorectal cancer), momelotinib (myelofibrosis), pirtobrutinib (mantle cell lymphoma, chronic lymphocytic leukemia, small lymphocytic lymphoma), quizartinib (Flt3-mutant acute myelogenous leukemia), repotrectinib (ROS1-positive lung cancer), and ritlecitinib (alopecia areata). All of the FDA-approved drugs are orally effective with the exception of netarsudil, temsirolimus, and trilaciclib. This review summarizes the physicochemical properties of all 80 FDA-approved small molecule protein kinase inhibitors including the molecular weight, number of hydrogen bond donors/acceptors, polar surface area, potency, solubility, lipophilic efficiency, and ligand efficiency.

Research Progress on the Use of Metformin in Leukemia Treatment

OPINION STATEMENT

Metformin is a first-line drug in the clinical treatment of type 2 diabetes. Its main molecular mechanism involves the activation of adenosine 5'-monophosphate-activated protein kinase (AMPK), which regulates cell energy metabolism. Many clinical studies have shown that metformin can reduce the incidence and mortality of cancer in patients with or without diabetes. In vitro studies also confirmed that metformin can inhibit proliferation, promote apoptosis, and enhance the response of cells to chemical drugs and other anticancer effects on a variety of leukemia cells. In recent years, leukemia has become one of the most common malignant diseases. Although great progress has been made in therapeutic approaches for leukemia, novel drugs and better treatments are still needed to improve the therapeutic efficacy of these treatments. This article reviews the application status and possible mechanism of metformin in the treatment of leukemia to further understand the anticancer mechanism of metformin and expand its clinical application.

Decoding leukemia at the single-cell level: clonal architecture, classification, microenvironment, and drug resistance

Leukemias are refractory hematological malignancies, characterized by marked intrinsic heterogeneity which poses significant obstacles to effective treatment. However, traditional bulk sequencing techniques have not been able to effectively unravel the heterogeneity among individual tumor cells. With the emergence of single-cell sequencing technology, it has bestowed upon us an unprecedented resolution to comprehend the mechanisms underlying leukemogenesis and drug resistance across various levels, including the genome, epigenome, transcriptome and proteome. Here, we provide an overview of the currently prevalent single-cell sequencing technologies and a detailed summary of single-cell studies conducted on leukemia, with a specific focus on four key aspects: (1) leukemia's clonal architecture, (2) frameworks to determine leukemia subtypes, (3) tumor microenvironment (TME) and (4) the drug-resistant mechanisms of leukemia. This review provides a comprehensive summary of current single-cell studies on leukemia and highlights the markers and mechanisms that show promising clinical implications for the diagnosis and treatment of leukemia.

Asperuloside regulates the proliferation, apoptosis, and differentiation of chronic myeloid leukemia cell line K562 through the RAS/MEK/ERK pathway

Context

Chronic myeloid leukemia (CML) is a malignant hematopoietic stem cell disease caused by excessive proliferation and abnormal differentiation of hematopoietic stem cells. Asperuloside (ASP) is considered to have good biological activity and may be a good anti-CML drug.

Objective

This study aimed to explore the effects and possible mechanisms of ASP on the biological behavior of K562 cells based on RNA-seq.

Materials and methods

The IC50 of ASP in K562 cells was calculated by the concentration-effect curve. Cell viability, apoptosis, and differentiation were detected by CCK8, flow cytometry, benzidine staining, and WB analysis, respectively. Further, RNA-seq was used to analyze the possible mechanism of ASP regulating K562 cells.

Results

ASP significantly inhibited the proliferation, and promoted apoptosis and differentiation of K562 cells. A total of 117 differentially expressed genes were screened by RNA-seq, mainly involved in the RAS/MEK/ERK pathway. PD98059 was used to inhibit the RAS/MEK/ERK pathway in K562 cells, and results confirmed that PD98059 could not only inhibit the RAS/MEK/ERK pathway, but also inhibit the regulation of ASP on the proliferation and differentiation of K562 cells.

Conclusion

ASP inhibited the proliferation, promoted apoptosis and differentiation of K562 cells by regulating the RAS/MEK/ERK pathway, and played a good anti-CML role.

Impact of Tyrosine Kinase Inhibitors (TKIs) on Growth in Children and Adolescents with Chronic Myeloid Leukemia: A Systematic Review

BACKGROUND

Chronic Myeloid Leukemia (CML) is a rare myeloproliferative disease in childhood. Treatment in CML includes Tyrosine Kinase Inhibitors (TKIs), which inhibit the cytoplasmic kinase BCR/ABL. Tyrosine kinases play a key role in the secretion of growth hormone and insulin-like growth factor 1 (IGF-1).

OBJECTIVE

The aim of this systematic review was to study the effect of TKIs on the growth of children and adolescents with CML.

METHODS

English-language publications were searched in the PubMed/Cochrane library/Google Scholar databases (2002-2023), and retrieved studies were assessed according to PRISMA-Statement and Newcastle- Ottawa-scale.

RESULTS

The search strategy yielded 1066 articles. After applying the inclusion/exclusion criteria, 941 were excluded based on title screening and 111 on abstract review. The systematic review included 14 articles (11 retrospective observational studies/3 clinical trials). Twelve studies reported data on the prevalence of growth disorders after the administration of 1st generation TKIs (imatinib). Two studies reported a negative effect of 2nd generation TKIs (dasatinib/nilotinib) on physical growth. Four studies recorded a decrease in height z-score after treatment compared to baseline. Two 1st-generation TKIs studies reported data on children's final height; one reported restoration of final height to normal after the onset of puberty, despite initial slowing, and the final height was lower than mid-parental target height. Serum IGF-1 levels were reported in 2 studies to be within normal range, while in 3 studies, a significant decrease was documented. Considerable study heterogeneity was observed related to dosage/duration of treatment/disease phase/stage of puberty/ethnicity.

CONCLUSION

A negative effect of TKIs on the growth and final height of children was noted.

[Optimizing the use of bosutinib in patients with chronic-phase chronic myeloid leukemia: Recommendations of a panel of experts from the Fi-LMC (French CML working group)]

The treatment of chronic myeloid leukemia relies on orally available tyrosine kinase inhibitors targeting the BCR::ABL1 oncoprotein. Bosutinib is a second generation adenosine triphosphate-competitive inhibitor approved for use in frontline adult chronic phase-chronic myeloid leukemia and all phases-chronic myeloid leukemia in the second line setting or beyond. Its efficacy was demonstrated in several pivotal clinical trials at 400mg once daily in the first line context and at 500mg once daily beyond first line. Bosutinib-related adverse events frequently occur early after treatment initiation and include gastro-intestinal symptoms and cytolytic hepatitis. These drug-related adverse events must be properly managed in order to preserve safety, efficacy and treatment acceptability. The French chronic myeloid leukemia study group gathered a panel of experts in hematology, pharmacology and hepatology in order to elaborate practical recommendations on the management of bosutinib treatment. These recommendations aim at optimizing the short and long-term tolerance and benefit/risk balance of bosutinib, mainly focusing at gastro-intestinal and liver toxicities.

Unusual presentation of extramedullary blast crisis in chronic myeloid leukemia: A case report

BACKGROUND

Extramedullary blast crisis in chronic myeloid leukemia (CML) is an uncommon occurrence of leukemic blast infiltration in regions other than the bone marrow. Malignant infiltration of the serosal membranes should be considered in cases where CML presents with ascites or pleural effusion.

CASE SUMMARY

A 23-year-old female with CML presented with progressively worsening ascites and pleural effusion despite first-line tyrosine kinase inhibitor treatment. Her blood work indicated leukocytosis with myelocyte bulge and 2% blasts. Analysis of the patient’s bone marrow confirmed the chronic phase of CML. Abdominal ultrasound revealed hepatosplenomegaly with ascites. The fluid investigation of both ascites and pleural effusion revealed a predominance of neutrophils with exudate. However, no acid-fast bacilli or growth was observed after culturing. Although hydroxyurea reduced cell counts, there was no observed effect on ascites or pleural effusion. Repeat investigation of the ascitic and pleural fluid revealed a polymorphous myeloid cell population consisting of myelocytes, metamyelocytes, band forms, neutrophils and a few myeloblasts. Extramedullary blast crisis was suspected, and mutation analysis was performed. We switched the patient to dasatinib. The patient’s symptoms were relieved, and ascites and pleural effusion diminished.

CONCLUSION

Serosal membrane involvement in CML is extremely rare. In this case, the patient responded well to dasatinib treatment.

Interleukin-9 production by type 2 innate lymphoid cells induces Paneth cell metaplasia and small intestinal remodeling

Paneth cell metaplasia (PCM) typically arises in pre-existing gastrointestinal (GI) diseases; however, the mechanistic pathway that induces metaplasia and whether PCM is initiated exclusively by disorders intrinsic to the GI tract is not well known. Here, we describe the development of PCM in a murine model of chronic myelogenous leukemia (CML) that is driven by an inducible bcr-abl oncogene. Mechanistically, CML induces a proinflammatory state within the GI tract that results in the production of epithelial-derived IL-33. The binding of IL-33 to the decoy receptor ST2 leads to IL-9 production by type 2 innate lymphoid cells (ILC2) which is directly responsible for the induction of PCM in the colon and tissue remodeling in the small intestines, characterized by goblet and tuft cell hyperplasia along with expansion of mucosal mast cells. Thus, we demonstrate that an extra-intestinal disease can trigger an ILC2/IL-9 immune circuit, which induces PCM and regulates epithelial cell fate decisions in the GI tract.

Comparison of cutaneous adverse events between second-generation tyrosine kinase inhibitors and imatinib for chronic myeloid leukemia: a systematic review and meta-analysis

BACKGROUND

Patients with chronic myeloid leukemia (CML) treated with tyrosine kinase inhibitors (TKIs) often experience cutaneous adverse events, such as rashes and pruritus. In this study, we aimed to compare the risks of cutaneous adverse events between imatinib- and second-generation TKI-treated patients with CML.

MATERIAL AND METHODS

Paired reviewers independently obtained studies from PubMed, Embase, and Cochrane Library published until 15 March 2022. The following terms were searched: (Leukemia, Myelogenous, Chronic and BCR-ABL Positive), chronic myeloid leukemia, tyrosine kinase inhibitor, TKI, imatinib, dasatinib, nilotinib, bosutinib, and radotinib. Two independent reviewers screened the results and selected articles on cutaneous adverse events. RevMan 5.4 and the Cochrane Collaboration tool were used to perform the meta-analysis and risk of bias assessment.

RESULTS AND CONCLUSION

Eleven trials involving 4502 patients were analyzed in this study. Patients treated with second-generation TKIs were significantly more likely to experience cutaneous adverse events than those treated with imatinib with a relative risk (RR) of 1.62 (95% confidence interval [CI], [1.25-2.09]). Except dasatinib (RR [95% CI], 1.39 [0.75-2.56]), the risk of adverse events was more with second-generation TKIs than with imatinib as follows: nilotinib (2.11 [1.53-2.90]), bosutinib (1.41 [1.07-1.86]), and radotinib (1.87 [1.33-2.63]). Rash was the most common cutaneous adverse event that was observed in 21.6% of cases across all grades, followed by pruritus (5.7%) and alopecia (4.3%). In conclusion, our findings suggest that cutaneous adverse events occur more frequently with second-generation TKIs than with imatinib. Therefore, effective management of the cutaneous outcome is necessary to achieve high patient adherence to medication and successful treatment with TKIs.

Bioinformatic analysis of the expression profile and identification of RhoGDI2 as a biomarker in imatinib-resistant K562 cells

OBJECTIVES

Chronic myeloid leukemia (CML) is an aggressive malignancy originating from hematopoietic stem cells. Imatinib (IM), the first-generation tyrosine kinase inhibitor, has greatly improved theliving quality of CML patients. However, owing to the recurrence and treatment failure coming from tyrosine kinase inhibitor (TKIs) resistance, some CML patients still bear poor prognosis. Therefore, we aimed to seek potential signaling pathways and specific biomarkers for imatinib resistance.

METHODS

We performed mRNA and miRNA expression profiling in imatinib-sensitive K562 cells (IS-K562) and imatinib-resistant K562 cells (IR-K562). Differentially expressed genes (DEGs) were identified and pathway enrichment analyses were performed to explore the potential mechanism. The protein-protein interaction (PPI) network and miRNA-mRNA regulatory network were constructed to explore potential relationships among these genes. RT-qPCR, western blot and CCK8 were used for further experiments.

RESULTS

A total of 623 DEGs and 61 differentially expressed miRNAs were identified. GO revealed that DEGs were mainly involved in cell adhesion, cell migration, differentiation, and inflammatory response. KEGG revealed that DEGs were typically enriched in the Rap1 signaling pathway, focal adhesion, proteoglycans and transcriptional misregulation in cancer, signaling pathways regulating pluripotency of stem cells and some immune-related pathways. The protein-protein interaction (PPI) network and miRNA-mRNA regulatory network revealed a web of diverse connections among genes. Finally, we proved that RHoGDI2 played a critical role in imatinib resistance.

CONCLUSION

The dynamic interplay between genes and signaling pathways is associated with TKIs resistance and RHoGDI2 is identified as a biomarker in IR-K562.

Stem Cell Responsiveness to Imatinib in Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disease characterized by the presence of the BCR-ABL fusion gene, which results from the Philadelphia chromosome. Since the introduction of tyrosine kinase inhibitors (TKI) such as imatinib mesylate (IM), the clinical outcomes for patients with CML have improved significantly. However, IM resistance remains the major clinical challenge for many patients, underlining the need to develop new drugs for the treatment of CML. The basis of CML cell resistance to this drug is unclear, but the appearance of additional genetic alterations in leukemic stem cells (LSCs) is the most common cause of patient relapse. However, several groups have identified a rare subpopulation of CD34+ stem cells in adult patients that is present mainly in the bone marrow and is more immature and pluripotent; these cells are also known as very small embryonic-like stem cells (VSELs). The uncontrolled proliferation and a compromised differentiation possibly initiate their transformation to leukemic VSELs (LVSELs). Their nature and possible involvement in carcinogenesis suggest that they cannot be completely eradicated with IM treatment. In this study, we demonstrated that cells from CML patients with the VSELs phenotype (LVSELs) similarly harbor the fusion protein BCR-ABL and are less sensitive to apoptosis than leukemic HSCs after IM treatment. Thus, IM induces apoptosis and reduces the proliferation and mRNA expression of Ki67 more efficiently in LHSCs than in leukemic LVSELs. Finally, we found that the expression levels of some miRNAs are affected in LVSELs. In addition to the tumor suppressor miR-451, both miR-126 and miR-21, known to be responsible for LSC leukemia-initiating capacity, quiescence, and growth, appear to be involved in IM insensitivity of LVSELs CML cell population. Targeting IM-resistant CML leukemic stem cells by acting via the miRNA pathways may represent a promising therapeutic option.

Effect of BCR::ABL1 transcript type and droplet digital polymerase chain reaction on successful treatment-free remission in chronic myeloid leukemia patients who discontinued tyrosine kinase inhibitor

Background

Droplet digital polymerase chain reaction (ddPCR) is an exact method of measurement.

Objectives

We conducted this study to identify the prognostic factors for successful treatment-free remission in patients with chronic-phase chronic myeloid leukemia who discontinued tyrosine kinase inhibitors (TKIs). We also aimed to validate ddPCR for predicting molecular relapse.

Design

This is a prospective, multicenter study.

Methods

We enrolled patients treated with TKIs for at least 3 years with a confirmed sustained deep molecular response (DMR) for at least 1 year. TKI was re-administered in patients who experienced the loss of major molecular response (MMR).

Results

A total of 66 patients from five institutions in South Korea were enrolled. During a median follow-up period of 16.5 months, 29/66 (43.9%) patients experienced molecular relapse; the probability of molecular relapse-free survival (RFS) at 6 or 12 months after TKI discontinuation was 65.6% or 57.8%, respectively, with most molecular relapses occurring within the first 7 months. All patients who lost MMR were re-treated with TKI, and all re-achieved MMR at a median of 2.8 months. E14a2 transcript type (p = 0.005) and longer DMR duration (⩾48 months) prior to TKI discontinuation (p = 0.002) were associated with prolonged molecular RFS and with sustained DMR. Patients with both e13a2 transcript type and detectable BCR::ABL1 (⩾MR5.0) by ddPCR at the time of TKI discontinuation showed shorter duration of molecular RFS (p = 0.015).

Conclusion

Our data suggest that transcript type and BCR::ABL1 transcript levels on ddPCR should be taken into consideration when deciding whether to discontinue TKI therapy.

Adherence to tyrosine kinase inhibitor and clinical outcomes in patients with chronic myeloid leukemia

PURPOSE

To ensure optimal care for patients with chronic myeloid leukemia (CML), adherence to tyrosine kinase inhibitors (TKIs) has emerged as a critical component. The objective of this study was to assess the impact of TKIs adherence on clinical outcomes in a cohort of Chinese CML patients who received treatment with TKIs.

METHODS

This retrospective study employed a cross-sectional design utilizing questionnaires to assess adherence to TKIs in a sample of 398 patients diagnosed with CML. Adherence was measured using the Morisky Medication Adherence Scale (MMAS-8), which dichotomizes patients into low, medium, and high adherence groups.

RESULTS

Of the patients included in this study, 34.2% were classified as highly adherent, with 43.2% and 22.6% of patients categorized as having medium and low adherence, respectively. Compared to the low-adherence group, patients in the medium- and high-adherence groups exhibited significantly higher rates of achieving major molecular response (MMR) and lower rates of switching TKIs. Moreover, patients who failed to adhere to TKIs treatment demonstrated significantly lower event-free survival and failure-free survival compared to those in the high-adherence group. Notably, regular molecular monitoring and utilization of the "CML Academy" mobile application were positively associated with increased TKI adherence. On the other hand, patients receiving third-generation or above first-line TKIs treatment displayed reduced adherence.

CONCLUSION

The findings suggest that high adherence to TKIs treatment confers clinical benefits to patients with CML. Accordingly, the implementation of effective guidance and intervention measures aimed at promoting adherence to TKIs therapy in real-world settings is imperative.

Preservation of fertility in female patients with hematologic diseases

Recent developments of assisted reproduction techniques turned possible to avoid the infertility consequences of oncologic treatments, but fertility preservation (FP) has been somewhat neglected in women with hematologic diseases undergoing gonadotoxic treatments. For these specific cases, the current options for FP include the cryopreservation of embryos, mature oocytes and ovarian tissue, and oocyte in-vitro maturation. We intend to make patients and clinicians aware of this important and relevant issue, and provide hematologists, assisted reproduction physicians and patients, with updated tools to guide decisions for FP. The physicians of the units responsible for female FP should always be available to decide on the best-individualized FP option in strict collaboration with hematologists. With a wide range of options for FP tailored to each case, a greater level of training and information is needed among clinicians, so that patients proposed to gonadotoxic treatments can be previously advised for FP techniques in hematological conditions. ABBREVIATED ABSTRACT: Recent developments of assisted reproduction techniques turned possible to preserve the fertility of women with hematologic diseases undergoing gonadotoxic treatments. Current options for fertility preservation in women with hematologic diseases are presented. It is imperative to offer fertility preservation to all women before starting any gonadotoxic treatment and in some cases after treatment. Fertility preservation methods enable to later achieve the desired pregnancy.

Progress of research on PD-1/PD-L1 in leukemia

Leukemia cells prevent immune system from clearing tumor cells by inducing the immunosuppression of the bone marrow (BM) microenvironment. In recent years, further understanding of the BM microenvironment and immune landscape of leukemia has resulted in the introduction of several immunotherapies, including checkpoint inhibitors, T-cell engager, antibody drug conjugates, and cellular therapies in clinical trials. Among them, the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis is a significant checkpoint for controlling immune responses, the PD-1 receptor on tumor-infiltrating T cells is bound by PD-L1 on leukemia cells. Consequently, the activation of tumor reactive T cells is inhibited and their apoptosis is promoted, preventing the rejection of the tumor by immune system and thus resulting in the occurrence of immune tolerance. The PD-1/PD-L1 axis serves as a significant mechanism by which tumor cells evade immune surveillance, and PD-1/PD-L1 checkpoint inhibitors have been approved for the treatment of lymphomas and varieties of solid tumors. However, the development of drugs targeting PD-1/PD-L1 in leukemia remains in the clinical-trial stage. In this review, we tally up the basic research and clinical trials on PD-1/PD-L1 inhibitors in leukemia, as well as discuss the relevant toxicity and impacts of PD-1/PD-L1 on other immunotherapies such as hematopoietic stem cell transplantation, bi-specific T-cell engager, chimeric antigen receptor T-cell immunotherapy.

Acquired miR-142 deficit in leukemic stem cells suffices to drive chronic myeloid leukemia into blast crisis

The mechanisms underlying the transformation of chronic myeloid leukemia (CML) from chronic phase (CP) to blast crisis (BC) are not fully elucidated. Here, we show lower levels of miR-142 in CD34+CD38- blasts from BC CML patients than in those from CP CML patients, suggesting that miR-142 deficit is implicated in BC evolution. Thus, we create miR-142 knockout CML (i.e., miR-142-/-BCR-ABL) mice, which develop BC and die sooner than miR-142 wt CML (i.e., miR-142+/+BCR-ABL) mice, which instead remain in CP CML. Leukemic stem cells (LSCs) from miR-142-/-BCR-ABL mice recapitulate the BC phenotype in congenic recipients, supporting LSC transformation by miR-142 deficit. State-transition and mutual information analyses of "bulk" and single cell RNA-seq data, metabolomic profiling and functional metabolic assays identify enhanced fatty acid β-oxidation, oxidative phosphorylation and mitochondrial fusion in LSCs as key steps in miR-142-driven BC evolution. A synthetic CpG-miR-142 mimic oligodeoxynucleotide rescues the BC phenotype in miR-142-/-BCR-ABL mice and patient-derived xenografts.

Hematological Adverse Events with Tyrosine Kinase Inhibitors for Chronic Myeloid Leukemia: A Systematic Review with Meta-Analysis

Chronic myeloid leukemia (CML) is treated with tyrosine kinase inhibitors (TKI) that target the pathological BCR-ABL1 fusion oncogene. The objective of this statistical meta-analysis was to assess the prevalence of other hematological adverse events (AEs) that occur during or after predominantly first-line treatment with TKIs. Data from seventy peer-reviewed, published studies were included in the analysis. Hematological AEs were assessed as a function of TKI drug type (dasatinib, imatinib, bosutinib, nilotinib) and CML phase (chronic, accelerated, blast). AE prevalence aggregated across all severities and phases was significantly different between each TKI (p < 0.05) for anemia-dasatinib (54.5%), bosutinib (44.0%), imatinib (32.8%), nilotinib (11.2%); neutropenia-dasatinib (51.2%), imatinib (29.8%), bosutinib (14.1%), nilotinib (14.1%); thrombocytopenia-dasatinib (62.2%), imatinib (30.4%), bosutinib (35.3%), nilotinib (22.3%). AE prevalence aggregated across all severities and TKIs was significantly (p < 0.05) different between CML phases for anemia-chronic (28.4%), accelerated (66.9%), blast (55.8%); neutropenia-chronic (26.7%), accelerated (63.8%), blast (36.4%); thrombocytopenia-chronic (33.3%), accelerated (65.6%), blast (37.9%). An odds ratio (OR) with 95% confidence interval was used to compare hematological AE prevalence of each TKI compared to the most common first-line TKI therapy, imatinib. For anemia, dasatinib OR = 1.65, [1.51, 1.83]; bosutinib OR = 1.34, [1.16, 1.54]; nilotinib OR = 0.34, [0.30, 0.39]. For neutropenia, dasatinib OR = 1.72, [1.53, 1.92]; bosutinib OR = 0.47, [0.38, 0.58]; nilotinib OR = 0.47, [0.42, 0.54]. For thrombocytopenia, dasatinib OR = 2.04, [1.82, 2.30]; bosutinib OR = 1.16, [0.97, 1.39]; nilotinib OR = 0.73, [0.65, 0.82]. Nilotinib had the greatest fraction of severe (grade 3/4) hematological AEs (30%). In conclusion, the overall prevalence of hematological AEs by TKI type was: dasatinib > bosutinib > imatinib > nilotinib. Study limitations include inability to normalize for dosage and treatment duration.

Multidisciplinary management in chronic myeloid leukemia improves cardiovascular risk measured by SCORE

Introduction: Cardiovascular events are one of the main long-term complications in patients with chronic myeloid leukemia (CML) receiving treatment with tyrosine kinase inhibitors (TKIs). The proper choice of TKI and the adequate management of risk factors may reduce cardiovascular comorbidity in this population. Methods: This study evaluated the cardiovascular risk of a cohort of patients with CML at diagnosis and after follow-up in a specialized cardiovascular risk consultation. In order to do this, we performed data analysis from 35 patients who received TKIs and were referred to the aforementioned consultation between 2015 and 2018 at our center. Cardiovascular risk factors were analyzed separately, as well as integrated into the cardiovascular SCORE, both at diagnosis and at the last visit to the specialized consultation. Results: At the time of diagnosis, 60% had some type of risk factor, 20% had a high or very high risk SCORE, 40% had an intermediate risk, and 40% belonged to the low risk category. During follow-up, the main cardiovascular adverse event observed was hypertension (diagnosed in 8 patients, 23%). 66% of patients quit smoking, achieving control of blood pressure in 95%, diabetes in 50%, weight in 76%, and dyslipidemia in 92%. 5.7% of patients suffered a thrombotic event and a significant percentage of patients showed a reduction in their SCORE. Conclusion: Our study shows the benefit of controlling cardiovascular risk factors through follow-up in a specialized consultation for patients with CML treated with TKI.