Codelivery of ivermectin and methyl dihydrojasmonate in nanostructured lipid carrier for synergistic antileukemia therapy.

Chronic myeloid leukemia is a life-threatening blood-cancer prevalent among children and adolescents. Research for innovative therapeutics combine drug-repurposing, phytotherapeutics and nanodrug-delivery. Ivermectin (Ivn) is a potent anthelmintic, repurposed for antileukemic-activity. However, Ivn exerts off-target toxicity. Methyl-dihydrojasmonate (MJ) is a phytochemical of known antileukemic potential. Herein, we developed for the first-time Ivn/MJ-coloaded nanostructured-lipid-carrier (Ivn@MJ-NLC) for leveraging the antileukemic-activity of the novel Ivn/MJ-combination while ameliorating possible adverse-effects. The developed Ivn@MJ-NLC possessed optimum-nanosize (97 ± 12.70 nm), PDI (0.33 ± 0.02), entrapment for Ivn (97.48 ± 1.48 %) and MJ (99.48 ± 0.57 %) and controlled-release of Ivn (83 % after 140 h) and MJ (80.98 ± 2.45 % after 48 h). In-vitro K562 studies verified Ivn@MJ-NLC prominent cytotoxicity (IC50 = 35.01 ± 2.23 µg/mL) with pronounced Ivn/MJ-synergism (combination-index = 0.59) at low-concentrations (5-10 µg/mL Ivn). Superior Ivn@MJ-NLC cytocompatibility was established on oral-epithelial-cells (OEC) with high OEC/K562 viability-ratio (1.49-1.85). The innovative Ivn@MJ-NLC enhanced K562-nuclear-fragmentation and afforded upregulation of caspase-3 and BAX (1.71 ± 0.07 and 1.45 ± 0.07-fold-increase, respectively) compared to control. Ex-vivo hemocompatibility and in-vivo-biocompatibility of parenteral-Ivn@MJ-NLC, compared to Ivn-solution, was verified via biochemical-blood analysis, histological and histomorphometric studies of liver and kidney tissues. Our findings highlight Ivn@MJ-NLC as an Ivn/MJ synergistic antileukemic platform, ameliorating possible adverse-effects.

[Optimal search conditions for identification of patients with chronic myeloid leukemia from Japanese National Health Insurance data].

This study investigated which conditions could be used to identify patients with chronic myeloid leukemia (CML) from a National Health Insurance claims dataset. During April 2012 and September 2018, 1,789,462 employees were enrolled in the dataset for Shizuoka Prefecture residents. The number of patients with the ICD-10 code for CML was 761. Among them, 246 who had been prescribed a tyrosine kinase inhibitor were considered as having true CML. The positive predictive value was calculated as 32.3% when CML was identified by ICD-10 code alone. Combination of ICD-10 code with prescribed drugs was required to accurately identify patients with CML from the insurance database.

Discovery and bioassay of disubstituted ß-elemene-NO donor conjugates: synergistic enhancement in the treatment of leukemia.

Natural products are essential sources of antitumor drugs. One such molecule, ß-elemene, is a potent antitumor compound extracted from Curcuma wenyujin. In the present investigation, a series of novel 13,14-disubstituted nitric oxide (NO)-donor ß-elemene derivatives were designed, with ß-elemene as the foundational compound, and subsequently synthesized to evaluate their therapeutic potential against leukemia. Notably, the derivative labeled as compound 13d demonstrated a potent anti-proliferative activity against the K562 cell line, with a high NO release. In vivo studies indicated that compound 13d could effectively inhibit tumor growth, exhibiting no discernible toxic manifestations. Specifically, a significant tumor growth inhibition rate of 62.9% was observed in the K562 xenograft tumor mouse model. The accumulated data propound the potential therapeutic application of compound 13d in the management of leukemia.

Canadian real-world experience of asciminib treatment in heavily pre-treated chronic myeloid leukemia (CML) patients who failed multiple lines of tyrosine kinase inhibitor (TKI) therapy.

BACKGROUND: Asciminib is a novel drug specifically targeting ABL myristoyl pocket in the ABL1 protein. METHODS: Forty one patients with chronic myeloid leukemia treated with asciminib from 2018 to 2022 were reviewed and analyzed for the efficacy and tolerability of asciminib using real-world experience data. RESULTS: The median age was 60 years (range 17-90) with a past history of a cardiovascular event in 21 patients (51%). Patients were pretreated with a median of 3 previous tyrosine kinase inhibitors (range 1-5). After a median of 12 months of asciminib (range 3-41), major molecular response (MMR) rate was 39% (n = 11/28) and 42% (n = 5/12) at 6 and 12 months, respectively. Molecular response with 2 log reduction (MR2) was noted in 54% (n = 15/28) and 50% (n = 6/12) at 6 and 12 months. The cumulative incidence of MMR and MR2 was 46.3% and 66% at 12 months. Five patients discontinued asciminib due to treatment failure (n = 3) or thrombocytopenia (n = 2). There were no cardiovascular events. Out of 7 patients treated with high dose asciminib for T315I mutation, 5 patients achieved MMR or deeper response. The event-free survival was 63% at 12 months. CONCLUSION: This study confirmed clinical efficacy and tolerability of asciminib with real-world experience.

Long-Term Efficacy of High-Dose Imatinib in Hispanic Patients Without Access to Second-Generation Tyrosine Kinase Inhibitors Treated in LATAM Centers.

BACKGROUND: While second-generation tyrosine kinase inhibitors (TKI) revolutionized treatment for patients with chronic myeloid leukemia (CML) who developed a suboptimal response to imatinib, many patients in developing countries are fixed to the latter due to socioeconomic barriers. Despite this scenario, scarce information is available to evaluate the clinical prognosis of these patients. METHODS: We conducted a retrospective cohort analysis to compare the overall mortality of patients with CML who developed a suboptimal response to a standard dose of imatinib and were treated with either high-dose imatinib or a second-generation TKI. We created a marginal structural model with inverse probability weighting and stabilized weights. Our primary outcome was overall survival (OS) at 150 months. Our secondary outcomes were disease-free survival (DFS) at 150 months and adverse events. RESULTS: The cohort included 148 patients, of which 32 received high-dose imatinib and 116 a second-generation TKI. No difference was found in the 150-month overall survival risk (RR: 95% CI 0.91, 0.55-1.95, P-value = .77; RD: -0.04, -0.3 to 0.21, P-value = .78) and disease-free survival (RR: 1.02, 95% CI 0.53-2.71, P-value = .96; RD: 0.01, -0.26 to 0.22, P-value = .96). There was also no difference in the incidence of adverse events in either group. CONCLUSION: Ideally, patients who develop a suboptimal response to imatinib should be switched to a second-generation TKI. If impossible, however, our findings suggest that patients treated with high-dose imatinib have a similar overall survival and disease-free survival prognosis to patients receiving a second-generation TKI.

Setting up a network of comprehensive care for patients with chronic myeloid leukemia: Lessons learned from Tanzania.

Over the last 2 decades, the introduction of targeted therapies and the advances in the detection of BCR::ABL1 oncogene have dramatically improved comprehensive care for patients with Chronic myeloid leukemia (CML). The once deadly malignancy has now transformed into a chronic disease with an overall patient survival approaching that of the age-matched general population. While excellent prognoses have been reported among CML patients in high-income countries, it is unfortunately not the same for those living in low and middle-income (LMIC) countries such as Tanzania. This disparity is largely contributed by barriers associated with the provision of comprehensive care including early diagnosis, access to treatment, and regular monitoring of the disease. In this review, we will share our experiences and lessons learned in setting up a network of comprehensive care for patients with CML in Tanzania.

Molecular BCR::ABL1 Quantification and ABL1 Mutation Detection as Essential Tools for the Clinical Management of Chronic Myeloid Leukemia Patients: Results from a Brazilian Single-Center Study.

Chronic myeloid leukemia (CML) is a well-characterized oncological disease in which virtually all patients possess a translocation (9;22) that generates the tyrosine kinase BCR::ABL1 protein. This translocation represents one of the milestones in molecular oncology in terms of both diagnostic and prognostic evaluations. The molecular detection of the BCR::ABL1 transcription is a required factor for CML diagnosis, and its molecular quantification is essential for assessing treatment options and clinical approaches. In the CML molecular context, point mutations on the ABL1 gene are also a challenge for clinical guidelines because several mutations are responsible for tyrosine kinase inhibitor resistance, indicating that a change may be necessary in the treatment protocol. So far, the European LeukemiaNet and the National Comprehensive Cancer Network (NCCN) have presented international guidelines on CML molecular approaches, especially those related to BCR::ABL1 expression. In this study, we show almost three years' worth of data regarding the clinical treatment of CML patients at the Erasto Gaertner Hospital, Curitiba, Brazil. These data primarily comprise 155 patients and 532 clinical samples. BCR::ABL1 quantification by a duplex-one-step RT-qPCR and ABL1 mutations detection were conducted. Furthermore, digital PCR for both BCR::ABL1 expression and ABL1 mutations were conducted in a sub-cohort. This manuscript describes and discusses the clinical importance and relevance of molecular biology testing in Brazilian CML patients, demonstrating its cost-effectiveness.

Mechanism of Procyanidin B2 in the Treatment of Chronic Myeloid Leukemia Based on Integrating Network Pharmacology and Molecular Docking.

OBJECTIVE: To study the pharmacological mechanism of procyanidin B2 (PCB2) on chronic myeloid leukemia (CML) by integrating network pharmacological methods systematically. METHODS: Firstly, the potential target genes of PCB2 were predicted by the pharmacological database and analysis platform (TCMSP and Pharmmapper). Meanwhile, the relevant target genes of CML were collected from GeneCards and DisGene. Pooled data were collected to screen for common target genes. Furthermore, the above intersection genes were imported into the String website to construct a protein-protein interaction (PPI) network, and the Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were further analyzed. Besides, molecular docking was performed to verify the possible binding conformation between PCB2 and candidate targets. Finally, MTT and RT-PCR experiments of K562 cells were performed to verify the above results of network pharmacology. RESULTS: A total of 229 PCB2 target genes were retrieved, among which 186 target genes had interaction with CML. The pharmacological effects of PCB2 on CML were related to some important oncogenes and signaling pathways. The top ten core targets predicted by Network Analysis were as follows: AKT1, EGFR, ESR1, CASP3, SRC, VEGFA, HIF1A, ERBB2, MTOR, and IGF1. Molecular docking studies confirmed that hydrogen bonding was the main interaction force of PCB2 binding targets. According to the molecular docking score, the following three target proteins were most likely to bind to PCB2: VEGFA (-5.5 kcal/mol), SRC (-5.1 kcal/mol), and EGFR (-4.6 kcal/mol). After treatment of PCB2 for 24h, mRNA expression levels of VEGFA and HIF1A decreased significantly in K562 cells. CONCLUSION: Through integrating network pharmacology combined with molecular docking, the study revealed the potential mechanism of PCB2 anti-chronic myeloid leukemia.

Combination of chemotherapy and gaseous signaling molecular therapy: Novel ß-elemene nitric oxide donor derivatives against leukemia.

This study aimed to design and synthesize active hybrids of ß-elemene and nitric oxide (NO) donor pharmacophore as potential agents for treating leukemia. Derivatives reported herein exerted better inhibitory effects against human chronic myeloid leukemia K562 cells compared to ß-elemene (IC50 > 100 µM). The most potent compound 18f showed an IC50 value of 0.53 µM against K562 cells, as well as a high NO release level in vitro. In the K562 xenograft tumor mice model, compound 18f effectively inhibited the growth of the tumor, with a significant inhibition rate of 73.18%. After treatment with compound 18f, the body weight of mice did not decrease, indicating that it possessed good safety profile. All these proved that compound 18f was an excellent potential agent against leukemia.

Mechanism of salidroside in the treatment of chronic myeloid leukemia based on the network pharmacology and molecular docking.

BACKGROUND: Salidroside is a phenolic natural product, which is a kind of Rhodiola rosea. It has been confirmed that it has inhibitory effects on chronic myeloid leukemia, but the specific performance of its molecular effects is still unclear. OBJECTIVE: To systematically study the pharmacological mechanism of salidroside on chronic myeloid leukemia by means of network pharmacology. METHODS: First, the possible target genes of salidroside were predicted through the Traditional Chinese Medicine Pharmacology Database and Analysis Platform, the target gene names were converted into standardized gene names using the Uniprot website. At the same time, the related target genes of chronic myeloid leukemia were collected from GeneCards and DisGenet; Collect summary data and screen for commonly targeted genes. Then, the above-mentioned intersected genes were imported into the String website to construct the protein-protein interaction (PPI) network, and the Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were further analyzed. To investigate the overall pharmacological effects of salidroside on chronic myeloid leukemia, we constructed a drug component-target gene-disease (CTD) network. Finally, molecular docking was performed to verify the possible binding conformation between salidroside and the candidate target. RESULTS: A total of 126 salidroside target genes were retrieved, and 106 of them had interactions with chronic myeloid leukemia. The pharmacological effects of salidroside on chronic myeloid leukemia are related to some important oncogenes and signaling pathways. Molecular docking studies confirmed that the main role of salidroside binding to the target genes is hydrogen bonding. CONCLUSIONS: We revealed the potential mechanism of action of salidroside against chronic myeloid leukemia, verified by network pharmacology combined with molecular docking. However, salidroside is a promising drug for the prevention and treatment of chronic myeloid leukemia, and further research is needed to prove it.

Guidelines for the treatment of chronic myeloid leukemia from the NCCN and ELN: differences and similarities.

Patients diagnosed with chronic myeloid leukemia (CML) in chronic phase can now have a life expectancy comparable to that of the general population thanks to the use of tyrosine kinase inhibitor (TKI) therapies. Although most patients with CML require lifelong TKI therapy, it is possible for some patients to achieve treatment-free remission. These spectacular results have been made possible by the development of superior treatment modalities as well as clinicians' efforts in strictly adhering to clinical guidelines such as the National Comprehensive Cancer Network (NCCN) and European Leukemia Network (ELN). CML treatment recommendations reported in these guidelines are the result of years of selecting and incorporating the most reliable evidence. In this review, we provide a synopsis of the differences and similarities that exist between the NCCN and ELN guidelines.

A clinician perspective on the treatment of chronic myeloid leukemia in the chronic phase.

Tyrosine kinase inhibitors (TKIs) have vastly improved long-term outcomes for patients with chronic myeloid leukemia (CML). After imatinib (a first-generation TKI), second- and third-generation TKIs were developed. With five TKIs (imatinib, dasatinib, bosutinib, nilotinib, and ponatinib) targeting BCR::ABL approved in most countries, and with the recent approval of asciminib in the USA, treatment decisions are complex and require assessment of patient-specific factors. Optimal treatment strategies for CML continue to evolve, with an increased focus on achieving deep molecular responses. Using clinically relevant case studies developed by the authors of this review, we discuss three major scenarios from the perspective of international experts. Firstly, this review explores patient-specific characteristics that affect decision-making between first- and second-generation TKIs upon initial diagnosis of CML, including patient comorbidities. Secondly, a thorough assessment of therapeutic options in the event of first-line treatment failure (as defined by National Comprehensive Cancer Network and European LeukemiaNet guidelines) is discussed along with real-world considerations for monitoring optimal responses to TKI therapy. Thirdly, this review illustrates the considerations and importance of achieving treatment-free remission as a treatment goal. Due to the timing of the writing, this review addresses global challenges commonly faced by hematologists treating patients with CML during the COVID-19 pandemic. Lastly, as new treatment approaches continue to be explored in CML, this review also discusses the advent of newer therapies such as asciminib. This article may be a useful reference for physicians treating patients with CML with second-generation TKIs and, as it is focused on the physicians' international and personal experiences, may give insight into alternative approaches not previously considered.

NOVEL-1st: an observational study to assess the safety and efficacy of nilotinib in newly diagnosed patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase in Taiwan.

Nilotinib has been approved for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (Ph+ CML-CP). However, the real-world evidence of nilotinib in newly diagnosed untreated Ph+ CML-CP is limited in Taiwan. The NOVEL-1st study was a non-interventional, multi-center study collecting long-term safety and effectiveness data in patients with newly diagnosed and untreated Ph+ CML-CP receiving nilotinib. We enrolled 129 patients from 11 hospitals. Overall, 1,466 adverse events (AEs) were reported; among these, 151 were serious and 524 were nilotinib-related. Common hematological AEs were thrombocytopenia (31.0%), anemia (20.9%), and leukopenia (14.0%); common nilotinib-related AEs were thrombocytopenia (29.5%), anemia (14.7%), and leukopenia (12.4%). Early molecular response, defined as BCR-ABL ≤ 10% at Month 3, was seen in 87.6% of patients. By 36 months, the cumulative rates of complete hematologic response, complete cytogenetic response, major molecular response, molecular response 4.0-log reduction, and molecular response 4.5-log reduction were 98.5, 92.5, 85.8, 65.0, and 45.0%, respectively. Nilotinib is effective and well-tolerated in patients with newly diagnosed Ph+ CML-CP in the real-world setting. Long-term holistic care and a highly tolerable AE profile may contribute to good treatment outcomes in Ph+ CML-CP under first-line treatment with nilotinib.

Icaritin induces cellular senescence by accumulating the ROS production and regulation of the Jak2/Stat3/p21 pathway in imatinib-resistant, chronic myeloid leukemia cells.

In patients with chronic myelogenous leukemia (CML), resistance to tyrosine kinase inhibitor (TKI) therapy, like imatinib, can cause death, progression to accelerated phase or blast crises, and the need for maintenance treatment. Icaritin is an active component of the genus Epimedium, a traditional Chinese herbal medicine. Icaritin has been shown to notably inhibit the growth of CML cells. To explore the potential mechanisms of inhibiting growth and inducing cell senescence in imatinib-resistant CML cells by icaritin, MTT assays were used to assess the cell viability. The apoptosis and cell cycle arrest were evaluated using flow cytometry. The SA-ß-Gal staining and the intracellular reactive oxygen species (ROS) production were measured using flow cytometry to detect the senescent cells. qRT-PCR was conducted to assess the expression of the cell cycle-associated proteins, and western blotting was used to analyze the expressions of the JAK2 and STAT3 phosphorylation proteins. The results showed that icaritin inhibited cell growth and induced cell senescence in imatinib-resistant CML cells, which is associated with the regulation of the JAK2/STAT3/P21 axis and accompanied by the accumulation of ROS. Our data suggest that icaritin is a promising therapeutic strategy for the treatment of imatinib-resistant patients with CML.

Clinical outcome of chronic myeloid leukemia patients who switch from first-line therapy with a second generation tyrosine kinase inhibitor to an alternative TKI.

While second generation tyrosine kinase inhibitors (2GTKIs) are highly effective therapies for chronic myeloid leukemia (CML), a significant minority of patients who initiate a 2GTKI will require a switch to an alternative TKI. The long-term outcomes of those who require a change in therapy after front-line 2GTKI therapy are largely undescribed. Here we describe the clinical outcomes associated with switch to an alternative TKI after first-line therapy with a 2GTKI. Of 232 patients who initiated a 2GTKI during the study period, 76 (33 %) switched to an alternative TKI. Reasons for switching included intolerance (79 %) and resistance (21 %). Among the 60 patients who switched due to intolerance, 53 (88 %) were able to achieve or maintain a major molecular response (MMR) with 5-year progression-free survival (PFS) 90.5 % (95 % CI 90.4-90.6 %). Amongst the 16 patients who switched due to resistance, 8 patients (50 %) were able to achieve MMR with 5-year PFS 80.4 % (95 % CI 80.2-80.6 %). Most patients who switched due to intolerance remained on their second-line TKI. Approximately 25 % of patients who initiate first-line 2GTKI in a real world setting will ultimately switch to an alternate TKI due to intolerance. Patients who switch for intolerance continue to enjoy excellent clinical outcomes.

Combination of PKCδ Inhibition with Conventional TKI Treatment to Target CML Models.

Numerous combinations of signaling pathway blockades in association with tyrosine kinase inhibitor (TKI) treatment have been proposed for eradicating leukemic stem cells (LSCs) in chronic myeloid leukemia (CML), but none are currently clinically available. Because targeting protein kinase Cδ (PKCδ) was demonstrated to eliminate cancer stem cells (CSCs) in solid tumors, we evaluated the efficacy of PKCδ inhibition in combination with TKIs for CML cells. We observed that inhibition of PKCδ by a pharmacological inhibitor, by gene silencing, or by using K562 CML cells expressing dominant-negative (DN) or constitutively active (CA) PKCδ isoforms clearly points to PKCδ as a regulator of the expression of the stemness regulator BMI1. As a consequence, inhibition of PKCδ impaired clonogenicity and cell proliferation for leukemic cells. PKCδ targeting in K562 and LAMA-84 CML cell lines clearly enhanced the apoptotic response triggered by any TKI. A strong synergism was observed for apoptosis induction through an increase in caspase-9 and caspase-3 activation and significantly decreased expression of the Bcl-xL Bcl-2 family member. Inhibition of PKCδ did not modify BCR-ABL phosphorylation but acted downstream of the oncogene by downregulating BMI1 expression, decreasing clonogenicity. PKCδ inhibition interfered with the clonogenicity of primary CML CD34+ and BCR-ABL-transduced healthy CD34+ cells as efficiently as any TKI while it did not affect differentiation of healthy CD34+ cells. LTC-IC experiments pinpointed that PKCδ inhibition strongly decreased the progenitors/LSCs frequency. All together, these results demonstrate that targeting of PKCδ in combination with a conventional TKI could be a new therapeutic opportunity to affect for CML cells.

Application of ZnO/CNT@Fe3O4nanocomposite in amplifying the anti-leukemic effects of Imatinib: a novel strategy to adjuvant therapy in chronic myeloid leukemia.

The advent of tyrosine kinase inhibitors in the therapeutic protocols of chronic myeloid leukemia (CML) was a revolution in the treatment strategies that guaranteed the achievement of complete remission for patients. However, due to different mutations bypassing the efficacy of Imatinib, novel and more effective treatments are indeed required for the treatment of CML. Our study declared that the combination of synthesized ZnO/CNT@Fe3O4nanocomposite with Imatinib decreased survival of CML-derived K562 cells, probably through inducing reactive oxygen species-mediated apoptosis. We also found improved cytotoxicity in the presence of a well known autophagy inhibitor, indicating that the apoptotic effect of this treatment is enhanced via autophagy suppression. Investigating the molecular mechanisms for the growth-suppressive effect of ZnO/CNT@Fe3O4-plus-Imatinib suggested that up-regulation of SIRT1 ceased cell cycle progression by increasing the expression of p21 and p27 cyclin-dependent kinase inhibitors. Notably, we reported here for the first time that either direct or indirect suppression of c-Myc results in enhanced anti-leukemic efficacy, suggesting that overexpression of c-Myc plays a contributory role in attenuating the efficacy of ZnO/CNT@Fe3O4-Imatinib in K562 cells. Given the promising effect of ZnO/CNT@Fe3O4in potentiating the anti-cancer effects of Imatinib in K562 cells, our study suggested that nanocomposite could be used as a tool for combined-strategy treatment. However, furtherin vivoexperiments are needed to provide clues for the safety and efficacy of this nanocomposite.

Evaluation of Hepatitis B Reactivation Among Patients With Chronic Myeloid Leukemia Treated With Tyrosine Kinase Inhibitors.

Hepatitis B reactivation (HBVr) in cancer patients is a well-established complication due to chemotherapy-induced immunosuppression. Studies have reported HBVr associated with immunosuppressive medications, such as rituximab, methotrexate, and high dose steroids. There are different risks for different types of chemotherapy with rituximab carrying one of the highest risks for hepatitis B reactivation. Tyrosine kinase inhibitors (TKIs) are the standard of care in patients with chronic myeloid leukemia (CML). The risk of HBVr in chronic myeloid leukemia has been reported in many studies, but to this date, there are no clear guidelines or recommendations regarding screening and monitoring of HBV in CML patients receiving TKIs. We conducted this review to identify the risk of HBVr in patients with CML who are treated with tyrosine kinase inhibitors. We recommend testing for HBV status in patients who are to be treated with TKIs and to consider giving prophylaxis in those who are positive for HBsAg at baseline. More studies are needed to assess the risk of reactivation in patients with Hepatitis B core antibody positive receiving TKIs. Currently, monitoring such patients for reactivation may be the best strategy.

Emodin Inhibits Resistance to Imatinib by Downregulation of Bcr-Abl and STAT5 and Allosteric Inhibition in Chronic Myeloid Leukemia Cells.

Imatinib-resistance is a significant concern for Bcr-Abl-positive chronic myelogenous leukemia (CML) treatment. Emodin, the predominant compound of traditional medicine rhubarb, was reported to inhibit the multidrug resistance by downregulating P-glycoprotein of K562/ADM cells with overexpression of P-glycoprotein in our previous studies. In the present study, we found that emodin can be a potential inhibitor for the imatinib-resistance in K562/G01 cells which are the imatinib-resistant subcellular line of human chronic myelogenous leukemia cells with overexpression of breakpoint cluster region-abelson (Bcr-Abl) oncoprotein. Emodin greatly enhanced cell sensitivity to imatinib, suppressed resistant cell proliferation and increased potentiated apoptosis induced by imatinib in K562/G01 cells. After treatment of emodin and imatinib together, the levels of p-Bcr-Abl and Bcr-Abl were significantly downregulated. Moreover, Bcr-Abl important downstream target, STAT5 and its phosphorylation were affected. Furthermore, the expression of Bcr-Abl and signal transducers and activators of transcription 5 (STAT5) related molecules, including c-MYC, MCL-1, poly(ADP-ribose)polymerase (PARP), Bcl-2 and caspase-3, were changed. Emodin also decreased Src expression and its phosphorylation. More importantly, emodin simultaneously targeted both the ATP-binding and allosteric sites on Bcr-Abl by molecular docking, with higher affinity with the myristoyl-binding site for enhanced Bcr-Abl kinase inhibition. Overall, these data indicated emodin might be an effective therapeutic agent for inhibiting resistance to imatinib in CML treatment.

Shikonin overcomes drug resistance and induces necroptosis by regulating the miR-92a-1-5p/MLKL axis in chronic myeloid leukemia.

Development of resistance to tyrosine kinase inhibitors (TKIs) targeting the BCR/ABL fusion protein represents a major challenge in the treatment of chronic myeloid leukemia (CML). Since apoptosis resistance is the fundamental mechanism impeding TKIs' therapeutic effects, alternative approaches that induce nonapoptotic cell death are being pursued to treat TKI-resistant CML. Induction of necroptosis, a distinct, caspase-independent form of programmed cell death, may be a valuable strategy in this respect. The present study shows that shikonin, an herbal compound used in traditional Chinese medicine, overcomes TKI resistance in BCR/ABL-positive CML cells by inducing necroptosis via activation of RIPK1/RIPK3/MLKL signaling. This effect occurs both in vitro and in vivo and involves downregulation of miR-92a-1-5p, a poor-prognosis marker frequently overexpressed in leukemia patients. Based on gene expression experiments, we conclude that miR-92a-1-5p promotes CML progression by inhibiting MLKL expression. Accordingly, we show that antagomiR-mediated in vivo inhibition of miR-92a-1-5p reduces the growth of CML tumors in mice through necroptosis induction. Our research suggests that therapies that relieve MLKL suppression by targeting miR-92a-1-5p may represent a useful strategy to treat TKI-refractory CML.