Best Practices in Chronic Myeloid Leukemia Monitoring and Management

Leukemia in pregnancy: Diagnosis and therapeutic approach (Review)

The present study aimed to evaluate the epidemiological, diagnostic and therapeutic data of hematological malignancies in pregnancy. Leukemia in pregnancy is rare, and literature data are not extensive. Risk factors, epidemiology and pathogenesis of these diseases are not fully developed. Furthermore, there is a detailed report on the complications in pregnancy and the overall (per trimester) management of these diseases, specifically their treatment strategy. The possibility of achieving a future pregnancy in women with leukemia is described in the present study. The limited clinical research data currently available is mainly due to the inability to conduct randomized clinical trials for ethical reasons. Further research is needed, firstly due to the importance of these diseases for the pregnant woman and the fetus, and secondly, due to the continuous development of novel anticancer drugs that aim to improve the prognosis of these diseases.

Comparative analysis of BCR::ABL1 p210 mRNA transcript quantification and ratio to ABL1 control gene converted to the International Scale by chip digital PCR and droplet digital PCR for monitoring patients with chronic myeloid leukemia

OBJECTIVES

Chronic myeloid leukemia (CML) is characterized by the Philadelphia chromosome, leading to the BCR::ABL1 fusion gene and hyper-proliferation of granulocytes. Tyrosine kinase inhibitors (TKIs) are effective, and minimal residual disease (MRD) monitoring is crucial. Digital PCR platforms offer increased precision compared to quantitative PCR but lack comparative studies.

METHODS

Eighty CML patient samples were analyzed in parallel using digital droplet PCR (ddPCR) (QXDx™ BCR-ABL %IS Kit) and chip digital PCR (cdPCR) (Dr. PCR™ BCR-ABL1 Major IS Detection Kit).

RESULTS

Overall, qualitative and quantitative agreement was good. Sensitivity analysis showed positive percentage agreement and negative percentage agreement were both ≥90 %, and the quadratic weighted kappa index for molecular response (MR) level categorization was 0.94 (95 %CI 0.89, 0.98). MR levels subgroup analysis showed perfect categorical agreement on MR level at MR3 or above, while 35.4 % (17/48) of patient samples with MR4 or below showed discordant categorizations. Overall, Lin's concordance correlation coefficient (CCC) for the ratio of %BCR::ABL1/ABL1 converted to the International Scale (BCR::ABL1 IS) was almost perfect quantitative agreement (Lin's CCC=0.99). By subgroups of MR levels, Lin's CCC showed a quantitative agreement of BCR::ABL1 IS decreased as MR deepened.

CONCLUSIONS

Both cdPCR and ddPCR demonstrated comparable performance in detecting BCR::ABL1 transcripts with high concordance in MR3 level or above. Choosing between platforms may depend on cost, workflow, and sensitivity requirements.

Validation of a novel NGS based BCR::ABL1 kinase domain mutation detection assay in Indian cohort

The efficacy and treatment outcome of a CML patient are heavily dependent on BCR::ABL1 kinase domain (KD) mutation status. Next-generation sequencing technology is a bright alternative to the previously used sanger sequencing method due to its global presence in diagnostic setups, massive parallel sequencing ability, and far better sensitivity. In the present study, we have demonstrated a new protocol for kinase domain mutation analysis using the next-generation sequencing (NGS) method using the ion torrent sequencing platform. This protocol uses RNA as the starting material, followed by nested PCR to amplify the fusion transcript, which is subsequently used as a template for NGS. Initial validation and comparison of this assay with the sanger sequencing (SS) method yielded 95.23% agreement. CML samples (n = 121) with a failure to TKI response were subjected to this newly developed NGS-based assay to detect KD mutations, from which samples were found to have mutations with a sensitivity ranging from 2.32 to 93.41%. A total of 34.71% of samples (n = 42) were found to be positive for one or more KD mutations, whereas 65.29% of samples (n = 81) were found to be negative. Nine samples out of 42 positive samples, i.e., 21.42%, were found to have compound mutations. This is one of the first studies from India, which includes more than 160 samples and is analyzed by the NGS approach for KD mutation analysis.

Combination of an aurora kinase inhibitor and the ABL tyrosine kinase inhibitor asciminib against ABL inhibitor-resistant CML cells

The development of BCR::ABL1-targeting tyrosine kinase inhibitors (TKIs) has improved the prognosis of patients with chronic myeloid leukemia (CML). However, resistance to ABL TKIs can develop in CML patients due to BCR::ABL1 point mutations and CML leukemia stem cell (LSC). Aurora kinases are essential kinases for cell division and regulate mitosis, especially the process of chromosomal segregation. Aurora kinase members also promote cancer cell survival and proliferation. This study analyzed whether aurora kinases were regulated in the progression of CML. It also evaluated the efficacy of the ABL TKI asciminib and the aurora kinase inhibitor LY3295668. The expressions of AURKA and AURKB were higher in the CML cells compared with normal cells using a public database (GSE100026). Asciminib or LY3295668 alone inhibited CML cells after 72 h, and cellular cytotoxicity was increased. The combined use of Asciminib and LY3295668 increased superior efficacy compared with either drug alone. Colony formation was reduced by cotreatment with asciminib and LY3295668. In the cell-cycle analyses, LY3295668 induced G2/M arrest. Cell populations in the sub-G1 phase were observed when cotreating with asciminib and LY3295668. The combination treatment also changed the mitochondrial membrane potential. In addition, AURKA shRNA transfectant cells had increased asciminib sensitivity. Combining asciminib and aurora kinase inhibition enhanced the efficacy and is proposed as a new therapeutic option for patients with CML. These findings have clinical implications for a potential novel therapeutic strategy for CML patients.

"Combination treatments of imatinib with astaxanthin and crocin efficiently ameliorate antioxidant status, inflammation and cell death progression in imatinib-resistant chronic myeloid leukemia cells"

BACKGROUND

Imatinib resistance remains a major obstacle in the treatment of chronic myelogenous leukemia (CML). Crocin (CRC) and astaxanthin (ATX) are phytochemicals with anti-cancer properties.

AIMS

This study aimed to explore the effects of combination treatment of Imatinib with CRC and ATX on Imatinib-resistant K562 (IR-K562) cells.

METHODS AND RESULTS

After the establishment of IR-K562 cells, growth inhibitory activity was determined by the MTT assay. To test the regeneration potential, a colony formation assay was performed. Cell cycle analyses were examined by flow cytometry. Cell injury was evaluated by lactate dehydrogenase (LDH) leakage. Real-time PCR was applied to assess the expression of IL6, TNF-α, STAT3, BAD, CASP3, TP53, and Bcl-2 genes. Caspase-3 activity was determined by a colorimetric assay. Antioxidant activity was measured using a diphenylpicrylhydrazyl (DPPH) assay. After 48 h of treatment, ATX (IC50 = 30µM) and CRC (IC50 = 190µM) significantly inhibited cell proliferation and colony formation ability, induced G1 cell cycle arrest and cell injury, upregulated the expression of apoptosis-associated genes, and downregulated the expression of anti-apoptotic and inflammatory genes. The combination of IM with ATX and/or CRC synergistically reduced cell viability (combination index [CI] < 1).

CONCLUSION

Our data suggest that IM shows better therapeutic efficacy at lower doses when combined with ATX and/or CRC.

Minimal Residual Disease Detection at RNA and Leukemic Stem Cell (LSC) Levels: Comparison of RT-qPCR, d-PCR and CD26+ Stem Cell Measurements in Chronic Myeloid Leukemia (CML) Patients in Deep Molecular Response (DMR)

A Deep Molecular Response (DMR), defined as a BCR::ABL1 transcript at levels ≤ 0.01% by RT-qPCR, is the prerequisite for the successful interruption of treatment among patients with Chronic Myeloid Leukemia (CML). However, approximately 50% of patients in Treatment-Free Remission (TFR) studies had to resume therapy after their BCR::ABL1 transcript levels rose above the 0.1% threshold. To improve transcript detection sensitivity and accuracy, transcript levels can be analyzed using digital PCR (dPCR). dPCR increases BCR::ABL1 transcript detection sensitivity 10-100 fold; however, its ability to better select successful TFR patients remains unclear. Beyond the role of the immune system, relapses may be due to the presence of residual leukemic stem cells (LSCs) that are transcriptionally silent. Flow cytometry can be used to identify and quantify circulating bone marrow Ph+ LSCs CD34+/CD38- co-expressing CD26 (dipeptidylpeptidase-IV). To date, the significance of circulating Ph+ LSCs in TFR is unclear. The aim of this work is to compare and examine the values obtained using the three different methods of detecting minimal residual disease (MRD) in CML at RNA (RT-qPCR and dPCR) and LSC (flowcytometry) levels among patients in TFR or exhibiting a DMR. The twenty-seven patients enrolled received treatment with either imatinib (12), dasatinib (6), nilotinib (7), bosutinib (1), or interferon (1). Twelve patients were in TFR, while the rest exhibited a DMR. The TFR patients had stopped therapy for less than 1 year (3), <3 years (2), 6 years (6), and 17 years (1). Blood samples were collected and tested using the three methods at the same time. Both d-PCR and LSCs showed higher sensitivity than RT-qPCR, exhibiting positive results in samples that were undetectable using RT-qPCR (17/27). None of the patients tested negative with d-PCR; however, 23/27 were under the threshold of 0.468 copies/μL, corresponding to a stable DMR. The results were divided into quartiles, and the lowest quartiles defined the lowest MRD. These data were strongly correlated in 15/27 patients, corresponding to almost half of the TFR patients. Indeed, the TFR patients, some lasting up to 17 years, corresponded to the lowest detectable DMR categories. To the best of our knowledge, this is the first attempt to analyze and compare DMRs in a CML population using standard (RT-qPCR) and highly sensitive (dPCR and LSCs) methods.

Rash with different types of BCR-ABL inhibitors in chronic myelogenous leukemia: a systematic review and meta-analysis

Objective: A meta-analysis was conducted to systematically review the risks of all-grade as well as high-grade rash in chronic myelogenous leukemia (CML) patients using different types of BCR-ABL inhibitors. Methods: Literature published between 2000 and April 2022 were searched using PubMed, Cochrane Library, Embase and ClinicalTrials.gov. Results: A total of 12 studies were included for meta-analysis. The results showed that the incidence of all-grade or high-grade rash associated with new-generation BCR-ABL inhibitors had no significant difference compared with a standard dose of imatinib. Subgroup analysis suggested that, compared with imatinib, the incidence of all grades of rash was higher in the nilotinib, bosutinib and ponatinib groups. Conclusion: For CML patients treated with nilotinib, bosutinib and ponatinib, the occurrence of skin toxicity should not be ignored.

The Application of Virtual Therapeutic Drug Monitoring to Assess the Pharmacokinetics of Imatinib in a Chinese Cancer Population Group

PURPOSE

Imatinib is used in gastrointestinal stromal tumours (GIST) and chronic myeloid leukaemia (CML). Oncology patients demonstrate altered physiology compared to healthy adults, e.g. reduced haematocrit, increased α-1 acid glycoprotein, decreased albumin and reduced glomerular filtration rate (GFR), which may influence imatinib pharmacokinetics. Given that Chinese cancer patients often report raised imatinib plasma concentrations and wider inter-individual variability reported in trough concentration when compared to Caucasian cancer patients, therapeutic drug monitoring (TDM) has been advocated.

METHOD

This study utilised a previously validated a Chinese cancer population and assessed the impact of imatinib virtual-TDM in Chinese and Caucasian cancer populations across a dosing range from 200-800 mg daily.

RESULTS

Staged dose titration to 800 mg daily, resulted in recapitulation to within the target therapeutic range for 50 % (Chinese) and 42.1% (Caucasian) subjects possessing plasma concentration < 550 ng/mL when dosed at 400 mg daily. For subjects with plasma concentrations >1500 ng/mL when dosed at 400 mg daily, a dose reduction to 200 mg once daily was able to recover 67 % (Chinese) and 87.4 % (Caucasian) patients to the target therapeutic range.

CONCLUSION

Virtual TDM highlights the benefit of pharmacokinetic modelling to optimising treatments in challenging oncology population groups.

From bench to bedside: bridging the gaps in best practices for real-world chronic myeloid leukemia care

INTRODUCTION

Although tyrosine kinase inhibitors (TKIs) determined an improvement of responses and overall survival (OS) in chronic phase chronic myeloid leukemia (CP-CML) patients, some patients still fail the achievement of important milestones.

AREAS COVERED

In this review, we focus on the need of appropriate molecular and mutational monitoring during TKI treatment with new laboratory tools and on new compounds developed to counteract the unmet clinical need in CP-CML.

EXPERT OPINION

The appropriate identification of BCR::ABL1 dependent and independent mechanisms of resistance with Next Generation Sequencing (NGS) and digital droplet PCR (ddPCR) can allow to improve the therapeutic strategies and prevent the onset of a failure to treatment. New compounds have been recently approved or are still in investigational trials to improve the response in some critical forms of resistance and/or intolerance to available TKIs.

The role of Fbxo5 in the development of human malignant tumors

Fbxo5 (F-Box only protein 5), as a substrate recognition subunit of SCF (SKP1-Cullin1-Fbox) protein, plays a crucial role in various cellular processes through ubiquitination and degradation of multiple proteins. In recent years, many studies have pointed out that Fbxo5 is critically involved in carcinogenesis. Moreover, targeting Fbxo5 could have a therapeutic potential for cancer therapy. This review focuses on the functions of Fbxo5 in various types of human malignancies and its underlying molecular mechanisms. This review might lay the foundation for enhancing future investigation on Fbxo5 functions in cancer development and progression.

Overcoming Resistance to Kinase Inhibitors: The Paradigm of Chronic Myeloid Leukemia

Protein kinases (PKs) play crucial roles in cellular proliferation and survival, hence their deregulation is a common event in the pathogenesis of solid and hematologic malignancies. Targeting PKs has been a promising strategy in cancer treatment, and there are now a variety of approved anticancer drugs targeting PKs. However, the phenomenon of resistance remains an obstacle to be addressed and overcoming resistance is a goal to be achieved. Chronic myeloid leukemia (CML) is the first as well as one of the best examples of a cancer that can be targeted by molecular therapy; hence, it can be used as a model disease for other cancers. This review aims to summarize up-to-date knowledge on the main mechanisms implicated in resistance to PK inhibitory therapies and to outline the main strategies that are being explored to overcome resistance. The importance of molecular diagnostics and disease monitoring in counteracting resistance will also be discussed.

Characterization of Drug Resistance in Chronic Myeloid Leukemia Cells Based on Laser Tweezers Raman Spectroscopy

Multidrug resistance is highly associated with poor prognosis of chronic myeloid leukemia. This work aims to explore whether the laser tweezers Raman spectroscopy (LTRS) could be practical in separating adriamycin-resistant chronic myeloid leukemia cells K562/adriamycin from its parental cells K562, and to explore the potential mechanisms. Detection of LTRS initially reflected the spectral differences caused by chemoresistance including bands assigned to carbohydrates, amino acid, protein, lipids, and nucleic acid. In addition, principal components analysis as well as the classification and regression trees algorithms showed that the specificity and sensitivity were above 90%. Moreover, the band data-based classification and regression tree model and receiver operating characteristic curve further determined some important bands and band intensity ratios to be reliable indexes in discriminating K562 chemoresistance status. Finally, we highlighted three metabolism pathways correlated with chemoresistance. This work demonstrates that the label-free LTRS analysis combined with multivariate statistical analyses have great potential to be a novel analytical strategy at the single-cell level for rapid evaluation of the chemoresistance status of K562 cells.

Molecular Monitoring of BCR-ABL Fusion Transcripts in Patients with Chronic Myeloid Leukemia During Treatment Using the Endpoint Fluorescence Method

OBJECTIVE

The purpose of the study was to compare results and evaluate the agreement between the endpoint fluorescence (EPF) method and quantitative real-time polymerase chain reaction (QPCR) during molecular monitoring of patients with chronic myeloid leukemia (CML) receiving treatment.

MATERIALS AND METHODS

The study was conducted at Molecular Lab of Riphah International University, Islamabad, Pakistan, from January 2017 to December 2018. A total of 150 blood specimens from 30 patients with CML were analyzed at regular intervals during therapy. The detection/quantification of transcript mRNA was done simultaneously using QPCR and the EPF method.

RESULTS

Out of a total of 150 RNA specimens analyzed, 117 (78%) specimens were positive, whereas 33 (22%) were negative for the transcript using both methods at various stages of treatment. Strong linear negative correlations between the cycle threshold and relative fluorescence unit values were observed with P <.0001 at 0, 3, 6, 9, and 12 months of treatment. No significant difference (P >.05) between the means of the BCR-ABL percentage was observed in either method at all stages of treatment. The bias between the 2 methods was calculated as 0.069 ± 3.50, and 95% limits of agreement were 6.92% to -6.79%.

CONCLUSION

We found that EPF is s simple method to detect/quantify BCR-ABL mRNA expression during treatment with comparable results to QPCR.

Targeting Leukemic Stem Cells in Chronic Myeloid Leukemia: Is It Worth the Effort?

Chronic myeloid leukemia (CML) is a classical example of stem cell cancer since it arises in a multipotent hematopoietic stem cell upon the acquisition of the t(9;22) chromosomal translocation, that converts it into a leukemic stem cell (LSC). The resulting BCR-ABL1 fusion gene encodes a deregulated tyrosine kinase that is recognized as the disease driver. Therapy with tyrosine kinase inhibitors (TKIs) eliminates progenitor and more differentiated cells but fails to eradicate quiescent LSCs. Thus, although many patients obtain excellent responses and a proportion of them can even attempt treatment discontinuation (treatment free remission [TFR]) after some years of therapy, LSCs persist, and represent a potentially dangerous reservoir feeding relapse and hampering TFR. Over the past two decades, intensive efforts have been devoted to the characterization of CML LSCs and to the dissection of the cell-intrinsic and -extrinsic mechanisms sustaining their persistence, in an attempt to find druggable targets enabling LSC eradication. Here we provide an overview and an update on these mechanisms, focusing in particular on the most recent acquisitions. Moreover, we provide a critical appraisal of the clinical relevance and feasibility of LSC targeting in CML.

Induction of apoptosis by Kola nut extract as a recent and promising treatment strategy for Leukemia

Kola nut extracts have recently been reported to contain chemopreventive compounds providing several pharmacological benefits. This study investigated Kola nut extracts' anti-cancer activity on human immortalized myelogenous leukemia cell line K562 through apoptosis and cell cycle arrest. Fresh Kola nuts were prepared as powder and dissolved in DMSO. Different concentrations (50, 100, 150, 200, and 250 μg/ml) of working solutions were prepared. The K562 cells were treated with the different concentrations of Kola nut extract or vehicle control (10% DMSO) followed by incubation at 37°C for 24, 48, and 72 hours, respectively. Treatment activity was investigated in K562 cells; by Resazurin, and FITC/Propidium Iodide and 7-AAD stained cells to evaluate apoptotic cells and the cell cycle's progression. Inhibition of leukemia cell proliferation was observed. The extract effectively induced cell death, early and late apoptosis by approximately 30% after 24 and 48 hours incubation, and an increase in the rate of dead cells by 50% was observed after 72 hours of incubation. Also, cell growth reduction was seen at high dose concentrations (150 and 200 µg/ml), as evident by cell count once treated with Kola nut extract. The total number of apoptotic cells increased from 5.8% of the control group to 27.4% at 250 µg/ml concentration. Moreover, Kola nut extracts' effects on K562 cells increased gradually in a dose and time-dependent manner. It was observed that Kola nut extracts could arrest the cell cycle in the G2/M phase as an increase in the number of cells by 29.8% and 14.6 % were observed from 9.8% and 5.2% after 24 and 48 hours of incubation, respectively. This increase was detected in a dose and time-dependent manner. Kola nut extracts can be used as a novel anti-cancer agent in Leukemia treatment as it has shown significant therapeutic potential and therefore provides new insights in understanding the mechanisms of its action. Keywords: Kola nut extracts, Leukemia, K562 cell line, Apoptosis, Cancer.

Predictive value of tyrosine phosphatase receptor gamma for the response to treatment tyrosine kinase inhibitors in chronic myeloid leukemia patients

Protein tyrosine phosphatase receptor gamma (PTPRG) is a member of the receptor-like family protein tyrosine phosphatases and acts as a tumor suppressor gene in different neoplasms. Recent studies reported the down-regulation of PTPRG expression levels in Chronic Myeloid Leukemia disease (CML). In addition, the BCR-ABL1 transcript level is currently a key predictive biomarker of CML response to treatment with Tyrosine Kinase Inhibitors (TKIs). The aim of this study was to employ flow cytometry to monitor the changes in the expression level of PTPRG in the white blood cells (WBCs) of CML patients at the time of diagnosis and following treatment with TKIs. WBCs from peripheral blood of 21 CML patients were extracted at diagnosis and during follow up along with seven healthy individuals. The PTPRG expression level was determined at protein and mRNA levels by both flow cytometry with monoclonal antibody (TPγ B9-2) and RT-qPCR, and BCR-ABL1 transcript by RT-qPCR, respectively. PTPRG expression was found to be lower in the neutrophils and monocytes of CML patients at time of diagnosis compared to healthy individuals. Treatment with TKIs nilotinib and Imatinib Mesylate restored the expression of PTPRG in the WBCs of CML patients to levels observed in healthy controls. Moreover, restoration levels were greatest in optimal responders and occurred earlier with nilotinib compared to imatinib. Our results support the measurement of PTPRG expression level in the WBCs of CML patients by flow cytometry as a monitoring tool for the response to treatment with TKIs in CML patients.

Moxetumomab pasudotox in heavily pre-treated patients with relapsed/refractory hairy cell leukemia (HCL): long-term follow-up from the pivotal trial

Background

Moxetumomab pasudotox is a recombinant CD22-targeting immunotoxin. Here, we present the long-term follow-up analysis of the pivotal, multicenter, open-label trial (NCT01829711) of moxetumomab pasudotox in patients with relapsed/refractory (R/R) hairy cell leukemia (HCL).

Methods

Eligible patients had received ≥ 2 prior systemic therapies, including ≥ 2 purine nucleoside analogs (PNAs), or ≥ 1 PNA followed by rituximab or a BRAF inhibitor. Patients received 40 µg/kg moxetumomab pasudotox intravenously on Days 1, 3, and 5 of each 28-day cycle for up to six cycles. Disease response and minimal residual disease (MRD) status were determined by blinded independent central review. The primary endpoint was durable complete response (CR), defined as achieving CR with hematologic remission (HR, blood counts for CR) lasting > 180 days.

Results

Eighty adult patients were treated with moxetumomab pasudotox and 63% completed six cycles. Patients had received a median of three lines of prior systemic therapy; 49% were PNA-refractory, and 38% were unfit for PNA retreatment. At a median follow-up of 24.6 months, the durable CR rate (CR with HR > 180 days) was 36% (29 patients; 95% confidence interval: 26–48%); CR with HR ≥ 360 days was 33%, and overall CR was 41%. Twenty-seven complete responders (82%) were MRD-negative (34% of all patients). CR lasting ≥ 60 months was 61%, and the median progression-free survival without the loss of HR was 71.7 months. Hemolytic uremic and capillary leak syndromes were each reported in ≤ 10% of patients, and ≤ 5% had grade 3–4 events; these events were generally reversible. No treatment-related deaths were reported.

Conclusions

Moxetumomab pasudotox resulted in a high rate of durable responses and MRD negativity in heavily pre-treated patients with HCL, with a manageable safety profile. Thus, it represents a new and viable treatment option for patients with R/R HCL, who currently lack adequate therapy.

Trial registration

ClinicalTrials.gov identifier: NCT01829711; first submitted: April 9, 2013. https://clinicaltrials.gov/ct2/show/NCT01829711

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13045-020-01004-y.

Higher Red Blood Cell Distribution Width is a Poor Prognostic Factor for Patients with Chronic Myeloid Leukemia

Purpose

Red blood cell distribution width (RDW) has been considered as a potential indicator of the effects of treatment or as a prognostic indicator for various malignancies. Most chronic myeloid leukemia (CML) patients are in the chronic phase, but some have transformed to accelerated phase or blast phase (blast crisis). However, the clinical significance of RDW in CML remains limited.

Patients and Methods

In the present study, detailed clinical information and the RDW of 168 healthy people and 153 CML patients (106 patients for the training cohort and 47 patients for the validation cohort) were retrospectively assessed.

Results

Multivariate analysis demonstrated that patient age (OR, 1.081; 95CI% 1.039~1.125; p < 0.001), platelet counts (OR, 0.997; 95CI% 0.994~0.999; p = 0.001) and RDW at admission (OR,1.469; 95CI% 1.121~1.925; p = 0.005) were significantly associated with the patients with advanced phase. Among CML patients in the chronic phase, higher RDW was significantly associated with overall survival (OS; p = 0.0008) and the event-free survival (EFS; p = 0.0221) among CML patients with chronic phase, but not with Transformation-free survival (TFS; p = 0.0821). Furthermore, higher RDW was associated with higher mortality compared to patients with low RDW (CML-associated deaths; p < 0.0001). In addition, a decline in RDW is associated with the treatment of CML patients with tyrosine kinase inhibitors, especially at 6 and 12 months after the start of treatment.

Conclusion

Higher RDW is a potential prognostic biomarker for chronic CML patients.

The clinical impact of time to response in de novo accelerated-phase chronic myeloid leukemia

We aimed to describe the impact of time to response on the outcomes of 75 patients with accelerated-phase chronic myeloid leukemia (CML-AP) at diagnosis. Patients had at least 1 feature of AP: blasts ≥15% (n = 2), basophils ≥20% (n = 19), platelets <100 × 109 /L (n = 7), cytogenetic clonal evolution (n = 34), or more than one factor (n = 13). Thirty-three patients received imatinib; 42 received a second-generation tyrosine kinase inhibitor (2GTKI) (19 dasatinib and 23 nilotinib). We used chi-square and Kaplan-Meier analyses to determine the impact of various degrees of molecular and cytogenetic response at early time points (3 and 6 months) on rates of overall cytogenetic and molecular response, overall survival (OS), event-free survival (EFS), transformation-free survival (TFS), and failure-free survival (FFS). After a median follow-up of 96 months (range: 18-224 months), the overall rate of complete cytogenetic response was 79%, of major molecular response, 71%, and of molecular reponse (MR)4.5, 59%. Patients who achieved a major cytogenetic response (MCyR) (n = 49) at 3 months had significantly better 3-year OS (94% vs 75%; P = .002), TFS (98% vs 73%; P < .001), EFS (93% vs 42%; P < .001), and FFS (83% vs 25%; P < .001) rates than patients who did not have MCyR at 3 months. Most (67%) who eventually achieved sustained MR4.5 had achieved MCyR at 3 months. In de novo CML-AP, early response at 3 and 6 months is a strong determinant of long-term outcome.

Philadelphia Chromosome-Positive Leukemia in the Lymphoid Lineage-Similarities and Differences with the Myeloid Lineage and Specific Vulnerabilities

Philadelphia chromosome (Ph) results from a translocation between the breakpoint cluster region (BCR) gene on chromosome 9 and ABL proto-oncogene 1 (ABL1) gene on chromosome 22. The fusion gene, BCR-ABL1, is a constitutively active tyrosine kinase which promotes development of leukemia. Depending on the breakpoint site within the BCR gene, different isoforms of BCR-ABL1 exist, with p210 and p190 being the most prevalent. P210 isoform is the hallmark of chronic myeloid leukemia (CML), while p190 isoform is expressed in majority of Ph-positive B cell acute lymphoblastic leukemia (Ph+ B-ALL) cases. The crucial component of treatment protocols of CML and Ph+ B-ALL patients are tyrosine kinase inhibitors (TKIs), drugs which target both BCR-ABL1 isoforms. While TKIs therapy is successful in great majority of CML patients, Ph+ B-ALL often relapses as a drug-resistant disease. Recently, the high-throughput genomic and proteomic analyses revealed significant differences between CML and Ph+ B-ALL. In this review we summarize recent discoveries related to differential signaling pathways mediated by different BCR-ABL1 isoforms, lineage-specific genetic lesions, and metabolic reprogramming. In particular, we emphasize the features distinguishing Ph+ B-ALL from CML and focus on potential therapeutic approaches exploiting those characteristics, which could improve the treatment of Ph+ B-ALL.

Mutations in the BCR-ABL1 kinase domain in patients with chronic myeloid leukaemia treated with TKIs or at diagnosis

The aim of the present study was to analyse the incidence of mutations in the BCR-ABL1 kinase region in patients with newly diagnosed or treated chronic myeloid leukaemia (CML), and the association between mutations clinicopathological characteristics. Samples were collected for mutation analysis from patients who exhibited tyrosine kinase inhibitor resistance following treatment or were in the accelerated or blast phase at diagnosis. The mutations in the breakpoint cluster region (BCR)-ABL proto-oncogene 1 (ABL1) kinase domain were evaluated using conventional sequencing or ultra-deep sequencing (UDS) of peripheral blood samples. Sanger sequencing and UDS of the cDNA region corresponding to the BCR-ABL1 kinase domain was performed. χ² test was used to assess the association of categorical variables between the mutated and non-mutated groups. In addition, the Kaplan-Meier method was applied to generate the survival curves. Sequencing detected 28 different mutations in 54 of the 175 (30.86%) patients with CML. A total of 14 (8.0%) patients presented with the T315I mutation, accounting for the largest proportion in the mutated group. Eight patients (4.6%) presented with more than one mutation, three (37.5%) of whom harboured T315I coexisting with other mutations, and for nine (5.1%) patients, the results differed between conventional sequencing and UDS, with the mutations being missed by conventional sequencing. The results form this study suggested that programing mutation analysis in patients with chronic myeloid leukaemia timely may guide the choice of TKIs.

Prospective assessment of NGS-detectable mutations in CML patients with nonoptimal response: the NEXT-in-CML study

In chronic myeloid leukemia (CML) patients, tyrosine kinase inhibitors (TKIs) may select for drug-resistant BCR-ABL1 kinase domain (KD) mutants. Although Sanger sequencing (SS) is considered the gold standard for BCR-ABL1 KD mutation screening, next-generation sequencing (NGS) has recently been assessed in retrospective studies. We conducted a prospective, multicenter study (NEXT-in-CML) to assess the frequency and clinical relevance of low-level mutations and the feasibility, cost, and turnaround times of NGS-based BCR-ABL1 mutation screening in a routine setting. A series of 236 consecutive CML patients with failure (n = 124) or warning (n = 112) response to TKI therapy were analyzed in parallel by SS and NGS in 1 of 4 reference laboratories. Fifty-one patients (22 failure, 29 warning) who were negative for mutations by SS had low-level mutations detectable by NGS. Moreover, 29 (27 failure, 2 warning) of 60 patients who were positive for mutations by SS showed additional low-level mutations. Thus, mutations undetectable by SS were identified in 80 out of 236 patients (34%), of whom 42 (18% of the total) had low-level mutations somehow relevant for clinical decision making. Prospective monitoring of mutation kinetics demonstrated that TKI-resistant low-level mutations are invariably selected if the patients are not switched to another TKI or if they are switched to a inappropriate TKI or TKI dose. The NEXT-in-CML study provides for the first time robust demonstration of the clinical relevance of low-level mutations, supporting the incorporation of NGS-based BCR-ABL1 KD mutation screening results in the clinical decision algorithms.

A Novel Methoxybenzyl 5-Nitroacridone Derivative Effectively Triggers G1 Cell Cycle Arrest in Chronic Myelogenous Leukemia K562 Cells by Inhibiting CDK4/6-Mediated Phosphorylation of Rb

Chronic myeloid leukemia (CML) is a malignant tumor caused by the abnormal proliferation of hematopoietic stem cells. Among a new series of acridone derivatives previously synthesized, it was found that the methoxybenzyl 5-nitroacridone derivative 8q has nanomolar cytotoxicity in vitro against human chronic myelogenous leukemia K562 cells. In order to further explore the possible anti-leukemia mechanism of action of 8q on K562 cells, a metabolomics and molecular biology study was introduced. It was thus found that most of the metabolic pathways of the G1 phase of K562 cells were affected after 8q treatment. In addition, a concentration-dependent accumulation of cells in the G1 phase was observed by cell cycle analysis. Western blot analysis showed that 8q significantly down-regulated the phosphorylation level of retinoblastoma-associated protein (Rb) in a concentration-dependent manner, upon 48 h treatment. In addition, 8q induced K562 cells apoptosis, through both mitochondria-mediated and exogenous apoptotic pathways. Taken together, these results indicate that 8q effectively triggers G1 cell cycle arrest and induces cell apoptosis in K562 cells, by inhibiting the CDK4/6-mediated phosphorylation of Rb. Furthermore, the possible binding interactions between 8q and CDK4/6 protein were clarified by homology modeling and molecular docking. In order to verify the inhibitory activity of 8q against other chronic myeloid leukemia cells, KCL-22 cells and K562 adriamycin-resistant cells (K562/ADR) were selected for the MTT assay. It is worth noting that 8q showed significant anti-proliferative activity against these cell lines after 48 h/72 h treatment. Therefore, this study provides new mechanistic information and guidance for the development of new acridones for application in the treatment of CML.

Expert opinion-management of chronic myeloid leukemia after resistance to second-generation tyrosine kinase inhibitors

Regardless of line of therapy, treatment goals in chronic phase chronic myeloid leukemia (CML) are: avoid progression to accelerated phase or blast crisis CML such that patients achieve a life expectancy comparable with that of the general population; avoid adverse events (AEs); and restore and maintain quality of life. The most important prognostic factor for achieving these goals is response to tyrosine kinase inhibitors (TKIs) at key milestones. For patients failing a TKI, a treatment change is mandatory to limit the risk of progression and death. There is currently no precise guideline for patients that fail a second-generation TKI, and there is a paucity of data to guide clinical decision making in this setting. There is, therefore, an unmet need for practical and actionable guidance on how to manage patients who fail a second-generation TKI. Although the term 'failure' includes patients failing for resistance or intolerance, the focus of this paper is failure of a second-generation TKI because of resistance. CML patients who fail their first second-generation TKI for true resistance need a more potent therapy. In these patients, the key issues to consider are the relative appropriateness of early allogeneic hematopoietic stem cell transplantation or the use of a further TKI. Selection of the next line of treatment after second-generation TKI resistance should be individualized and must be based on patient-specific factors including cytogenetics, mutation profile, comorbidities, age, previous history of AEs with prior TKI therapy, and risk profile for AEs on specific TKIs. This expert opinion paper is not in conflict with existing recommendations, but instead represents an evolution of previous notions, based on new data, insights, and clinical experience. We review the treatment options for patients resistant to second-generation TKI therapy and provide our clinical opinions and guidance on key considerations for treatment decision making.

Monitoring of Minimal Residual Disease (MRD) in Chronic Myeloid Leukemia: Recent Advances

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm caused by the BCR-ABL1 fusion gene generation as a consequence of the t(9;22)(q34;q11) rearrangement. The identification of the BCR-ABL1 transcript was of critical importance for both CML diagnosis and minimal residual disease (MRD) monitoring. In this review, we report the recent advances in the CML MRD monitoring based on RNA, DNA and protein analysis. The detection of the BCR-ABL1 transcript by the quantitative reverse-transcriptase polymerase chain reaction is the gold standard method, but other systems based on digital PCR or on GeneXpert technology have been developed. In the last years, DNA-based assays showed high sensitivity and specificity, and flow cytometric approaches for the detection of the BCR-ABL1 fusion protein have also been tested. Recently, new MRD monitoring systems based on the detection of molecular markers other than the BCR-ABL1 fusion were proposed. These approaches, such as the identification of CD26+ leukemic stem cells, microRNAs and mitochondrial DNA mutations, just remain preliminary and need to be implemented. In the precision medicine era, the constant improvement of the CML MRD monitoring practice could allow clinicians to choose the best therapeutic algorithm and a more accurate selection of CML patients eligible for the tyrosine kinase inhibitors discontinuation.

Statistics and measurable residual disease (MRD) testing: uses and abuses in hematopoietic cell transplantation

SERIES EDITORS' NOTE

The decision whether to recommend a transplant to someone with acute leukemia in first remission is complex and challenging. Diverse, often confounded co-variates interact to influence one's recommendation. Briefly, the decision metric can be viewed in three spheres: (1) subject-; (2) transplant-; and (3) disease-related co-variates. Subject-related co-variates include items such as age and comorbidities. Transplant-related co-variates include items such as donor-types, graft source, proposed conditioning and pre- and post-transplant immune suppression.But what of disease-related variables? Previously haematologists relied on co-variates such as WBC at diagnosis, chemotherapy cycles to achieve first remission, cytogenetics and most recently, mutation topography. However, these co-variates have largely been replaced by results of measurable residual disease (MRD)-testing. Many chemotherapy-only and transplant studies report strong correlations between results of MRD-testing on therapy outcomes such as cumulative incidence of relapse (CIR), leukemia-free survival (LFS) or survival. (CIR makes biological sense in a transplant context whereas LFS and survival do not give competing causes of death such as transplant-related mortality (TRM), graft-versus-host disease and interstitial pneumonia unrelated to relapse probability).This raises the question of how useful results are of MRD-testing in predicting CIR after transplants. Elsewhere we discussed accuracy and precision of MRD-testing in predicting outcomes of therapy of acute myeloid leukemia (Estey E, Gale RP. Leukemia 31:1255-1258, 2017; Hourigan CS, Gale RP, Gormley NJ, Ossenkoppele GJ, Walter RB. Leukemia 31:1482-1490, 2017). Briefly put, not terribly good. Although results of MRD-testing are often the most powerful predictor of CIR in multivariable analyses, the C-statistic (a measure of prediction accuracy) is often only about 0.75. This is much better than flipping a fair coin but far from ideal.In the typescript which follows, Othus and colleagues discuss statistical issues underlying MRD-testing in the context of haematopoietic cell transplants. We hope readers, especially haematologists who often need to make transplant recommendations to people with acute leukemia in first remission, will read it carefully and critically. The bottom line is MRD-test data are useful but considerable uncertainty is unavoidable with substantial false-positive and -negative rates. We need to acknowledge this uncertainty to ourselves and to the people we counsel. The authors quote Voltaire who said: Doubt is not a pleasant condition, but certainty is an absurd one. Sadly so, but we do the best we can. Robert Peter Gale, Imperial College London, and Mei-Jie Zhang, Medical College of Wisconsin and CIBMTR.

The multi-tyrosine kinase inhibitor ponatinib for chronic myeloid leukemia: Real-world data

Development of the highly selective targeted tyrosine kinase inhibitors (TKIs) has expanded the therapeutic options for chronic myeloid leukemia (CML). Patients undergoing TKI therapy should be closely monitored to ensure that the best therapeutic response and quality of life are achieved, and to control suboptimal responses and adverse events. Despite the high rate of response using current first-line TKIs, treatment failure may still occur, and resistance is considered a challenge in the treatment of patients with CML. The third-generation TKI, ponatinib, is a potent orally bioavailable pan BCR-ABL inhibitor that inhibits both wild-type and mutant BCR-ABL1 kinase, including the "gatekeeper" T315I mutation, which is resistant to all other currently available TKIs. This paper reviews the effectiveness, feasibility, and safety of ponatinib in the real-life clinical management of CML. Potential prognostic factors in identifying patients most likely to benefit from ponatinib treatment will be discussed, and case presentations illustrating situations encountered in real-life clinical practice are described. Ponatinib is effective in patients who have received prior TKIs in clinical studies as well as under real-life conditions. Nevertheless, the risk/benefit balance must be evaluated for each patient, particularly considering disease state, mutational status, treatment line, intolerance/resistance to prior TKIs, age, frailty, and specific comorbidities.

Novel and Rare Fusion Transcripts Involving Transcription Factors and Tumor Suppressor Genes in Acute Myeloid Leukemia

Approximately 18% of acute myeloid leukemia (AML) cases express a fusion transcript. However, few fusions are recurrent across AML and the identification of these rare chimeras is of interest to characterize AML patients. Here, we studied the transcriptome of 8 adult AML patients with poorly described chromosomal translocation(s), with the aim of identifying novel and rare fusion transcripts. We integrated RNA-sequencing data with multiple approaches including computational analysis, Sanger sequencing, fluorescence in situ hybridization and in vitro studies to assess the oncogenic potential of the ZEB2-BCL11B chimera. We detected 7 different fusions with partner genes involving transcription factors (OAZ-MAFK, ZEB2-BCL11B), tumor suppressors (SAV1-GYPB, PUF60-TYW1, CNOT2-WT1) and rearrangements associated with the loss of NF1 (CPD-PXT1, UTP6-CRLF3). Notably, ZEB2-BCL11B rearrangements co-occurred with FLT3 mutations and were associated with a poorly differentiated or mixed phenotype leukemia. Although the fusion alone did not transform murine c-Kit+ bone marrow cells, 45.4% of 14q32 non-rearranged AML cases were also BCL11B-positive, suggesting a more general and complex mechanism of leukemogenesis associated with BCL11B expression. Overall, by combining different approaches, we described rare fusion events contributing to the complexity of AML and we linked the expression of some chimeras to genomic alterations hitting known genes in AML.

Targeted Killing of Monocytes/Macrophages and Myeloid Leukemia Cells with Pro-Apoptotic Peptides

Several cells of myeloid origin, such as monocytes and macrophages are involved in various human disorders, including cancer and inflammatory diseases. Hence, they represent attractive therapeutic targets. Here we developed three lytic hybrid peptides, by fusing a monocyte- and macrophage-binding peptide to pro-apoptotic peptides, and investigated their killing potency on blood monocytes, macrophages, and leukemia cells. We first showed that the targeting NW peptide is effective for depleting monocytes from whole peripheral blood mononuclear cells (PBMCs). Incubating the cells with biotin-conjugated NW peptide, and the subsequent capture on streptavidin-conjugated magnetic beads, depleted monocytes from the PBMCs. The NW peptide also depleted myeloid leukemia blasts from patient PBMCs. The treatment of the PBMCs with the lytic hybrid NW-KLA peptide killed monocytes, but not lymphocytes and primary mammary epithelial cells. Additionally, the fusion peptide exhibited a potent toxicity against macrophages and leukemia cells. The free lytic KLA peptide did not affect cells. Similarly, a second lytic hybrid peptide killed macrophages, leukemia cell lines, and blood leukemia blasts from patients with acute and chronic myeloid leukemia. The IC₅₀ towards target cells were in the low macromolar range (4–12 µM). Overall, the data indicate that the NW peptide could be a potential drug delivery agent for monocytes, macrophages, and leukemia cells. Moreover, the engineered lytic hybrid peptides acting alone, or in combination with other therapeutic agents, might benefit many cancer patients and overcome drug resistance.

Analytical Validation of a Highly Sensitive, Multiplexed Chronic Myeloid Leukemia Monitoring System Targeting BCR-ABL1 RNA

This study describes the analytical performance of the QuantideX qPCR BCR-ABL IS Kit, the first Food and Drug Administration–cleared assay designed to monitor breakpoint cluster region–Abelson tyrosine-protein kinase 1 (BCR-ABL1) fusion transcripts isolated from peripheral blood specimens from patients with chronic myeloid leukemia. This multiplex real-time quantitative RT-PCR assay amplifies both e13a2 and e14a2 Major BCR-ABL1 transcripts and the reference target ABL1. The test results are provided in international scale (IS) values by incorporating armored RNA-based calibrators that have defined IS values tied directly to the World Health Organization BCR-ABL1 Primary Reference Materials, without the necessity of determining and maintaining conversion factors. For each batch run, the integrated interpretive software evaluates run and specimen quality control metrics (including a sufficient amount of ABL1 control transcripts to ensure a minimal limit of detection) and calculates both molecular response (MR) and %IS values for each specimen. The test has a limit of detection of MR4.7 (0.002%IS) and a linear range from MR0.3 (50%IS) to MR4.7 (0.002%IS) for both Major transcripts. Single-site and multisite precision studies demonstrated a maximum SD of 0.13 MR (30% CV within the assay range between MR0.7 and MR3.7). The performance of this BCR-ABL1 monitoring test meets all of the clinical guideline recommendations for sensitivity and IS reporting for the management of chronic myeloid leukemia patients.

Digital PCR improves the quantitation of DMR and the selection of CML candidates to TKIs discontinuation

Treatment‐free remission (TFR) by tyrosine kinase inhibitors (TKI) discontinuation in patients with deep molecular response (DMR) is a paramount goal in the current chronic myeloid leukemia (CML) therapeutic strategy. The best DMR level by real‐time quantitative PCR (RT‐qPCR) for TKI discontinuation is still a matter of debate. To compare the accuracy of digital PCR (dPCR) and RT‐qPCR for BCR‐ABL1 transcript levels detection, 142 CML patients were monitored for a median time of 24 months. Digital PCR detected BCR‐ABL1 transcripts in the RT‐qPCR undetectable cases. The dPCR analysis of the samples, grouped by the MR classes, revealed a significant difference between MR^4.0 and MR^4.5 (P = 0.0104) or MR^5.0 (P = 0.0032). The clinical and hematological characteristics of the patients grouped according to DMR classes (MR^4.0 vs MR^4.5‐5.0) were superimposable. Conversely, patients with dPCR values <0.468 BCR‐ABL1 copies/µL (as we previously described) showed a longer DMR duration (P = 0.0220) and mainly belonged to MR^4.5‐5.0 (P = 0.0442) classes compared to patients with higher dPCR values. Among the 142 patients, 111 (78%) discontinued the TKI treatment; among the 111 patients, 24 (22%) lost the MR^3.0 or MR^4.0. RT‐qPCR was not able to discriminate patients with higher risk of MR loss after discontinuation (P = 0.8100). On the contrary, according to dPCR, 12/25 (48%) patients with BCR‐ABL1 values ≥0.468 and 12/86 (14%) patients with BCR‐ABL1 values <0.468 lost DMR in this cohort, respectively (P = 0.0003). Treatment‐free remission of patients who discontinued TKI with a dPCR <0.468 was significantly higher compared to patients with dPCR ≥ 0.468 (TFR at 2 years 83% vs 52% P = 0.0017, respectively). In conclusion, dPCR resulted in an improved recognition of stable DMR and of candidates to TKI discontinuation.

Chronic myelogenous leukemia, a still unsolved problem: pitfalls and new therapeutic possibilities

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder of hematopoietic stem cells. At the molecular level, the disorder results from t(9;22)(q34;q11) reciprocal translocation between chromosomes, which leads to the formation of an oncogenic BCR–ABL gene fusion. Instead of progress in the understanding of the molecular etiology of CML and the development of novel therapeutic strategies, clinicians still face many challenges in the effective treatment of patients. In this review, we discuss the pathways of diagnosis and treatment of patients, as well as the problems appearing in the course of disease development. We also briefly refer to several aspects regarding the current knowledge on the molecular basis of CML and new potential therapeutic targets.

Analysis of major BCR-ABL1 mRNA by digital polymerase chain reaction is useful for prediction of international scale

BACKGROUND

Major BCR-ABL1 mRNA in patients with chronic myeloid leukemia (CML) has generally been analysed by real-time polymerase chain reaction (PCR). Application of the international scale (IS) for the quantification of major BCR-ABL1 mRNA has been recommended in several sets of guidelines, including those of the European LeukemiaNet. The aim of this study was to clarify the efficacy of digital PCR technology for the IS of BCR-ABL1 mRNA in the patients with CML by comparing with real-time PCR.

METHODS

The analysis of BCR-ABL1 mRNA was carried out by the Ipsogen^® BCR-ABL1 Mbcr IS-MMR DX Kit (Qiagen), and the QuantStudio 3D Digital PCR System (Thermo Fisher Scientific‎) using 20 peripheral blood samples obtained from the 9 patients with CML at Sapporo Medical University Hospital.

RESULTS

The correlation between the data obtained by digital PCR and by real-time PCR was really high at R = 0.96. The detection limit of digital PCR was up to 0.003% and was equal to IS with 0.01% or less in comparison with real-time PCR.

CONCLUSIONS

Digital PCR technology is promising for predicting the IS value with similar efficacy to real-time PCR and should be useful for simple monitoring of the effects of tyrosine kinase inhibitor (TKI) treatments.

Differential genomics and transcriptomics between tyrosine kinase inhibitor-sensitive and -resistant BCR-ABL-dependent chronic myeloid leukemia

Previously, it has been stated that the BCR-ABL fusion-protein is sufficient to induce Chronic Myeloid Leukemia (CML), but additional genomic-changes are required for disease progression. Hence, we profiled control and tyrosine kinase inhibitors (TKI) alone or in combination with other drug-treated CML-samples in different phases, categorized as drug-sensitive and drug-resistant on the basis of BCR-ABL transcripts, the marker of major molecular-response. Molecular-profiling was done using the molecular-inversion probe-based-array, Human Transcriptomics-Array2.0, and Axiom-Biobank genotyping-arrays. At the transcript-level, clusters of control, TKI-resistant and TKI-sensitive cases were correlated with BCR-ABL transcript-levels. Both at the gene- and exon-levels, up-regulation of MPO, TPX2, and TYMS and down-regulation of STAT6, FOS, TGFBR2, and ITK lead up-regulation of the cell-cycle, DNA-replication, DNA-repair pathways and down-regulation of the immune-system, chemokine- and interleukin-signaling, TCR, TGF beta and MAPK signaling pathways. A comparison between TKI-sensitive and TKI-resistant cases revealed up-regulation of LAPTM4B, HLTF, PIEZO2, CFH, CD109, ANGPT1 in CML-resistant cases, leading to up-regulation of autophagy-, protein-ubiquitination-, stem-cell-, complement-, TGFβ- and homeostasis-pathways with specific involvement of the Tie2 and Basigin signaling-pathway. Dysregulated pathways were accompanied with low CNVs in CP-new and CP-UT-TKI-sensitive-cases with undetectable BCR-ABL-copies. High CNVs (previously reported gain of 9q34) were observed in BCR-ABL-independent and -dependent TKI, non-sensitive-CP-UT/AP-UT/B-UT and B-new samples. Further, genotyping CML-CP-UT cases with BCR-ABL 0-to-77.02%-copies, the identified, rsID239798 and rsID9475077, were associated with FAM83B, a candidate for therapeutic resistance. The presence of BCR-ABL, additional genetic-events, dysregulated-signaling-pathways and rsIDs associated with FAM83B in TKI-resistant-cases can be used to develop a signature-profile that may help in monitoring therapy.

Effects of nilotinib on leukaemia cells using vibrational microspectroscopy and cell cloning

S-FTIR and Raman microspectroscopies identify spectral markers of sensitivity/resistance to nilotinib in leukaemia cell clones.

Assessment of the Number and Phenotype of Macrophages in the Human BMB Samples of CML

Macrophages have emerged as a key player in tumor biology. However, their number and phenotype in human bone marrow of biopsy (BMB) samples of chronic myeloid leukemia (CML) and their association with disease progression from an initial chronic phase (CP) to accelerated phase (AP) to advanced blast phase (BP) are still unclear. BMB samples from 127 CML patients and 30 patients with iron-deficiency anemia (IDA) as control group were analyzed by immunohistochemistry. The expression levels of CD68, CD163, and CD206 in BMB samples of CML patients were significantly higher than those in the patients of control group (P < 0.01), and we observed that their positive expression was gradually elevated during the transformation of CML-CP to AP to BP (P < 0.01). However, the expressions of CD68, CD163, and CD206 in released group were downregulated and contrasted to these in control group; there exists statistical significance (P < 0.01). The percentage ratio of CD163 and CD206 to CD68 was pronounced to be increasing from CML-CP to AP to BP (P < 0.01). Hence, the higher proportion of CD68⁺, CD163⁺ and CD206⁺ macrophages in BMB samples can be considered a key factor for disease progression of CML patients. Targeting macrophages, especially the M2 phenotype may help in designing therapeutic strategies for CML.