Chronic myeloid leukemia: 2012 update on diagnosis, monitoring, and management

Antibody-Free Fluorine-Assisted Metabolic Sequencing of RNA N4-Acetylcytidine

N4-Acetylcytidine (ac4C) has been found to affect a variety of cellular and biological processes. For a mechanistic understanding of the roles of ac4C in biology and disease, we present an antibody-free, fluorine-assisted metabolic sequencing method to detect RNA ac4C, called "FAM-seq". We successfully applied FAM-seq to profile ac4C landscapes in human 293T, HeLa, and MDA cell lines in parallel with the reported acRIP-seq method. By comparison with the classic ac4C antibody sequencing method, we found that FAM-seq is a convenient and reliable method for transcriptome-wide mapping of ac4C. Because this method holds promise for detecting nascent RNA ac4C modifications, we further investigated the role of ac4C in regulating chemotherapy drug resistance in chronic myeloid leukemia. The results indicated that drug development or combination therapy could be enhanced by appreciating the key role of ac4C modification in cancer therapy.

Expression of GnT-III decreases chemoresistance via negatively regulating P-glycoprotein expression: Involvement of the TNFR2-NF-κB signaling pathway

The phenomenon of multidrug resistance (MDR) is called chemoresistance with respect to the treatment of cancer, and it continues to be a major challenge. The role of N-glycosylation in chemoresistance, however, remains poorly understood. Here, we established a traditional model for adriamycin resistance in K562 cells, which are also known as K562/adriamycin-resistant (ADR) cells. Lectin blot, mass spectrometry, and RT-PCR analysis showed that the expression levels of N-acetylglucosaminyltransferase III (GnT-III) mRNA and its products, bisected N-glycans, are significantly decreased in K562/ADR cells, compared with the levels in parent K562 cells. By contrast, the expression levels of both P-glycoprotein (P-gp) and its intracellular key regulator, NF-κB signaling, are significantly increased in K562/ADR cells. These upregulations were sufficiently suppressed by the overexpression of GnT-III in K562/ADR cells. We found that the expression of GnT-III consistently decreased chemoresistance for doxorubicin and dasatinib, as well as activation of the NF-κB pathway by tumor necrosis factor (TNF) α, which binds to two structurally distinct glycoproteins, TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2), on the cell surface. Interestingly, our immunoprecipitation analysis revealed that only TNFR2, but not TNFR1, contains bisected N-glycans. The lack of GnT-III strongly induced TNFR2's autotrimerization without ligand stimulation, which was rescued by the overexpression of GnT-III in K562/ADR cells. Furthermore, the deficiency of TNFR2 suppressed P-gp expression while it increased GnT-III expression. Taken together, these results clearly show that GnT-III negatively regulates chemoresistance via the suppression of P-gp expression, which is regulated by the TNFR2-NF/κB signaling pathway.

A decade of approved first-in-class small molecule orphan drugs: Achievements, challenges and perspectives

In the past decade (2011-2020), there was a growing interest in the discovery and development of orphan drugs for the treatment of rare diseases. However, rare diseases only account for a population of 0.65‰-1‰ which usually occur with previously unknown biological mechanisms and lack of specific therapeutics, thus to increase the demands for the first-in-class (FIC) drugs with new biological targets or mechanisms. Considering the achievements in the past 10 years, a total of 410 drugs were approved by U.S. Food and Drug Administration (FDA), which contained 151 FIC drugs and 184 orphan drugs, contributing to make up significant numbers of the approvals. Notably, more than 50% of FIC drugs are developed as orphan drugs and some of them have already been milestones in drug development. In this review, we aim to discuss the FIC small molecules for the development of orphan drugs case by case and highlight the R&D strategy with novel targets and scientific breakthroughs.

Detachment of Hexokinase II From Mitochondria Promotes Collateral Sensitivity in Multidrug Resistant Chronic Myeloid Leukemia Cells

Chronic Myeloid Leukemia is a neoplastic disease characterized by the abnormal expansion of hematopoietic cells with compromised functions. Leukemic cells often display a multidrug resistance phenotype, enabling them to evade a number of structurally unrelated cytotoxic compounds. One of those mechanisms relies on the high expression of efflux transporters, such as the ABC proteins, whose activity depends on the hydrolysis of ATP to reduce intracellular drug accumulation. In the present work, we employed a well-known erythroleukemia cell line, K562, and a multidrug resistant derivative cell, FEPS, to evaluate how hexokinase II, a key regulator for the rate-limiting step glycolysis, contributes to the establishment of the multidrug resistance phenotype. We found that multidrug resistant cells primarily resort to glycolysis to generate ATP. Clotrimazole reduced the expression of mitochondrial hexokinase II, which destabilized bioenergetic parameters such as reactive oxygen species production, ATP, and glutathione levels on multidrug resistant cells. This impaired the activity of ABCC1, leading to increased drug accumulation and cell death. In summary, we propose that decoupling of hexokinase II from the mitochondria emerges as a promising strategy to generate collateral sensitivity and aid in the management of chronic myeloid leukemia in chemotherapy-refractory patients.

Turkey real-life data: demographic features, treatment results and effects of comorbidities in chronic myeloid leukemia

Aim:

This study aimed to identify patient characteristics, treatment patterns and outcomes and to evaluate the effects of presence of comorbidities at diagnosis in chronic phase (CP)-chronic myeloid leukemia (CML) patients in Turkey.

Materials & methods:

Hospital records between 2005 and 2018 were retrospectively reviewed.

Results:

Of 861 CP-CML patients included, 31% had at least one comorbidity at diagnosis. Sex, cardiovascular disease status at diagnosis and molecular (at least major) and cytogenetic (partial and complete) responses were the independent predictors of survival.

Conclusion:

The response rates of CP-CML patients to the tyrosine kinase inhibitors were satisfactory. In addition to tolerability and side effect profiles of drugs, comorbidity status of patients should also be considered in treatment choice in CML patients.

This study aimed to identify patient characteristics, treatment patterns and outcomes and to evaluate the effects of presence of comorbidities at diagnosis in chronic phase (CP)-chronic myeloid leukemia (CML) patients in Turkey. Hospital records of patients between 2005 and 2018 were retrospectively reviewed. Of the included 861 CP-CML patients, 31% had at least one comorbidity at diagnosis. The survival of the patients was affected by sex, cardiovascular disease status at diagnosis, and molecular (at least major) and cytogenetic (partial and complete) responses. The response rates of CP-CML patients to the tyrosine kinase inhibitors were satisfactory. In addition to tolerability and side effect profiles of drugs, comorbidity status of patients should also be considered in treatment choice in CML patients.

Evaluation of anti-tumor effect of the exopolysaccharide from new cold-adapted yeast, Rhodotorula mucilaginosa sp. GUMS16 on chronic myeloid leukemia K562 cell line

Recently, the development and application of fungal exopolysaccharides (EPS) as natural biopolymers are on the rise. The present study is based on the investigation of possible antiproliferative and antioxidant activities of EPS from the Rhodotorula mucilaginosa sp. GUMS16 on BCR-ABL positive cells (K562). The cytotoxicity, colony formation assays lactate and dehydrogenase (LDH) activity were performed to assess the possible cancer cell death. To elucidate the underlying antiproliferative mechanism of the EPS, cell cycle analysis following real-time PCR (gene expression assessment) were evaluated. The results indicated that, the EPS with an IC50 dose of 1500 μg/ml, reduced the viability of K562 cells without having toxic effects on normal cells as well as decrease in size and number of colonies in EPS-treated group (p < 0.0001). The increase of LDH was 2.75 times more than the control (p < 0.0001). Gene expression revealed up- and down-regulation of apoptotic and anti-apoptotic genes in EPS group compared with the control. Moreover, the DPPH scavenging activity of the EPS in treated cells was significantly higher than the control group (p < 0.0001). Taken together, we concluded that the EPS from GUMS16 strain is able to inhibit the growth of K562 cells besides having antioxidant activities.

Pharmacogenomics in Children

Historically genetics has not been considered when prescribing drugs for children. However, it is clear that genetics are not only an important determinant of disease in children but also of drug response for many important drugs that are core agents used in the therapy of common problems in children. Advances in therapy and in the ethical construct of children's research have made pharmacogenomic assessment for children much easier to pursue. It is likely that pharmacogenomics will become part of the therapeutic decision-making process for children, notably in areas such as childhood cancer where weighing benefits and risks of therapy is crucial.

Age- and Gender-Independent Association of XRCC1 Arg399Gln Polymorphism with Chronic Myeloid Leukemia

Purpose

DNA damage to hematopoietic progenitor cells is an essential factor for leukemia development as a failure of the host DNA repair system to fix errors in DNA. This study aimed to assess the association of XRCC1 gene polymorphisms including Arg194Trp, Arg399Gln, and Arg280His with the risk of development of CML in Sudanese population.

Patients and Methods

The present study was conducted on 186 newly diagnosed patients with CML, aged 19–70 years (118 males and 68 females; mean age of 46.15±13.91 years) and 186 normal healthy controls (123 males and 63 females; mean age of 44.94±8.97 years). Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay was utilized to analyze the XRCC1 (Arg194Trp, Arg399Gln, and Arg280His) gene polymorphisms.

Results

The genotypic frequencies of Arg399Gln polymorphism in cases were 131 (70.4%) homozygous Arg/Arg, 46 (24.7%) homozygous Gln/Gln, and 9 (4.8%) heterozygous Arg/Gln as compared to the controls ie, 153 (82.3%), 73 (14.5%), and 6 (3.2%), respectively. The Arg399Gln variant genotypic frequencies significantly differed between the cases and controls (χ² = 7.249, P = 0.027). By comparison, no statistically significant difference was observed in the variant genotype frequencies between the cases and controls in terms of Arg194Trp and Arg280His polymorphisms.

Conclusion

XRCC1 Arg399Gln gene polymorphism might have an important role in increasing the risk of chronic myeloid leukemia among Sudanese patients. Furthermore, all tested three polymorphisms showed no association of risk of the development of CML with age and gender.

Evaluation of the outcomes in patients with chronic myeloid leukemia treated with imatinib in 18-year follow-up

The objective of this paper is to examine the effects of Imatinib on patients who are at the chronic phase of chronic myeloid leukemia (CML). Method: Totally, 79 patients with CML who received the treatment between 2003 and 2020 entered the study. The patients were evaluated in terms of molecular response rate and overall survival (OS). Results: About 75.9% of patients achieved deep molecular response in mean follow-up of 89.92 months. The OS rate was about 91.2%. Conclusion: There was no considerable cumulative toxicity with Imatinib long-term use. A high percent of patients had a deep molecular response.

A systematic review of modeling and simulation approaches in designing targeted treatment technologies for Leukemia Cancer in low and middle income countries

Virtual experimentation is a widely used approach for predicting systems behaviour especially in situations where resources for physical experiments are very limited. For example, targeted treatment inside the human body is particularly challenging, and as such, modeling and simulation is utilised to aid planning before a specific treatment is administered. In such approaches, precise treatment, as it is the case in radiotherapy, is used to administer a maximum dose to the infected regions while minimizing the effect on normal tissue. Complicated cancers such as leukemia present even greater challenges due to their presentation in liquid form and not being localised in one area. As such, science has led to the development of targeted drug delivery, where the infected cells can be specifically targeted anywhere in the body. Despite the great prospects and advances of these modeling and simulation tools in the design and delivery of targeted drugs, their use by Low and Middle Income Countries (LMICs) researchers and clinicians is still very limited. This paper therefore reviews the modeling and simulation approaches for leukemia treatment using nanoparticles as an example for virtual experimentation. A systematic review from various databases was carried out for studies that involved cancer treatment approaches through modeling and simulation with emphasis to data collected from LMICs. Results indicated that whereas there is an increasing trend in the use of modeling and simulation approaches, their uptake in LMICs is still limited. According to the review data collected, there is a clear need to employ these tools as key approaches for the planning of targeted drug treatment approaches.

Extracellular matrix and its therapeutic potential for cancer treatment

The extracellular matrix (ECM) is one of the major components of tumors that plays multiple crucial roles, including mechanical support, modulation of the microenvironment, and a source of signaling molecules. The quantity and cross-linking status of ECM components are major factors determining tissue stiffness. During tumorigenesis, the interplay between cancer cells and the tumor microenvironment (TME) often results in the stiffness of the ECM, leading to aberrant mechanotransduction and further malignant transformation. Therefore, a comprehensive understanding of ECM dysregulation in the TME would contribute to the discovery of promising therapeutic targets for cancer treatment. Herein, we summarized the knowledge concerning the following: (1) major ECM constituents and their functions in both normal and malignant conditions; (2) the interplay between cancer cells and the ECM in the TME; (3) key receptors for mechanotransduction and their alteration during carcinogenesis; and (4) the current therapeutic strategies targeting aberrant ECM for cancer treatment.

Chronic myeloid leukemia-from the Philadelphia chromosome to specific target drugs: A literature review

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm and was the first neoplastic disease associated with a well-defined genotypic anomaly - the presence of the Philadelphia chromosome. The advances in cytogenetic and molecular assays are of great importance to the diagnosis, prognosis, treatment, and monitoring of CML. The discovery of the breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) 1 fusion oncogene has revolutionized the treatment of CML patients by allowing the development of targeted drugs that inhibit the tyrosine kinase activity of the BCR-ABL oncoprotein. Tyrosine kinase inhibitors (known as TKIs) are the standard therapy for CML and greatly increase the survival rates, despite adverse effects and the odds of residual disease after discontinuation of treatment. As therapeutic alternatives, the subsequent TKIs lead to faster and deeper molecular remissions; however, with the emergence of resistance to these drugs, immunotherapy appears as an alternative, which may have a cure potential in these patients. Against this background, this article aims at providing an overview on CML clinical management and a summary on the main targeted drugs available in that context.

A case of dasatinib-induced focal segmental glomerulosclerosis in a patient with Philadelphia chromosome positive chronic myeloid leukemia

Focal segmental glomerulosclerosis is a common glomerular histological lesion, which is usually characterised by non-nephrotic range proteinuria or nephrotic syndrome. It may be idiopathic or occurs secondarily to drugs, diabetes, obesity or HIV nephropathy and other infections. Dasatinib, a tyrosine kinase inhibitor that has been used for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia, has a few renal adverse effects. Exceptional cases with non-nephrotic range proteinuria have been reported in relation with dasatinib. In this case, we report a patient with symptoms of nephrotic syndrome and nephrotic range proteinuria, who was diagnosed as focal segmental glomerulosclerosis by kidney biopsy after treated with dasatinib.

Myeloid Leukemias: A Glance at Middle Eastern Centers

BACKGROUND AND OBJECTIVES

Myeloid leukemias (MLs) are clonal stem cell disorders affecting myeloid lineage cells. Advances in cytogenetic and molecular studies partially disclosed the mystery about risk factors and pathophysiology of MLs. Regarding incidence, risk factors, response to treatment, and overall survival of patients, research showed differences among different countries. However, the Western registry data are the basis for the documented description of MLs in medical textbooks. This research aimed to study MLs in Middle Eastern health centers. Egypt has the highest population in the Middle East; furthermore, 96.6% of the population is native Egyptians; accordingly the study focused on Egypt.

PATIENTS AND METHODS

Data of 468 patients with MLs were collected from hospital records at two big tertiary health centers. They were grouped into group 1 (chronic myeloid leukemia, CML) and group 2 (acute myeloid leukemia, AML); the latter was subgrouped into 2a (primary AML) and 2b (secondary AML).

RESULTS AND CONCLUSIONS

The median age of patients was 43 years; males predominate in group 2a and females in groups 1 and 2b. 37.2% of group 1 patients were treated with Gleevec. Hematopoietic stem cell transplantation was planned for only 5% of group 2 and 18% relapsed. Of groups 1 and 2 patients, 25% and 12%, respectively, stopped follow up, and 15% and 35% died. ORR and overall survival were 53%, 27% and 7%, 0.4% for groups 1 and 2, respectively. Conclusively, this study showed a young age of ML patients, with female predominance in CML, and poor outcome. This reflected racial, ethnic and risk factor differences in incidence of MLs.

Quantitative Assay of Mutated Nucleophosmin in Acute Myeloid Leukemia

Background

In our previous work, we provided strong evidence that nucleophosmin (NPM) gene mutation has an important role in leukemogenesis of primary acute myeloid leukemia (AML). Furthermore, we speculated a new targeted therapy in patients with primary AML and bearing mutated NPM (mNPM). Based on these results together with findings of other researchers, it was essential to develop a method for accurate detection of mNPM.

Methods

Our method based on utilizing the most recent flow cytometeric techniques and instruments in measuring mNPM. Attributed to their availability and technical feasibility, we used human leukemia cell lines to validate our method.

Results

The main findings were differential expression of wild-type NPM (wtNPM) within the same sample. Furthermore flow cytometry (FCM) was a simple straightforward tool for quantitative assay of mNPM.

Conclusions

In this work we developed an innovative technique that could enable quantitative assay of mNPM, and ease its use as a biomarker in cytogenetic and molecular prognostication of primary AML. In addition the study suggested that FCM could differentiate mNPM expression within cells of the same patient thus could be used for monitoring of minimal residual disease.

Drug-drug interaction study of imatinib and voriconazole in vitro and in vivo

Background: In clinical practice, common problem polypharmacy could result in the increased risks of drug-drug interactions (DDIs). Co-administered imatinib (IMA) and voriconazole (VOR) as one treatment protocol in cancer patients with fungal infections are common.Purpose: The aim of the present study was to assess the potential DDIs associated with the concurrent use of IMA and VOR in rat liver microsomes (RLMs) and in rats.Methods and results: The concentration levels of IMA, VOR, and their metabolites N-desmethyl IMA (CGP74588) and N-oxide voriconazole (N-oxide VOR) were determined by ultra performance liquid chromatography-tandem mass spectrometry. In vitro study of RLMs, VOR inhibited the IMA metabolism with the half-maximal inhibitory concentration (IC₅₀) of 105.20 μM, while IC₅₀ for IMA against VOR was 61.30 μM. After co-administered IMA and VOR in rats, the C _max of IMA was increased significantly, while the AUC_0→t, AUC_0→∞, and C _max of CGP74588 were decreased significantly. In addition, similar results were also found that the main pharmacokinetic parameters (AUC_0→t, AUC_0→∞, MRT_0→∞, T _max, and C _max) of VOR were increased significantly, while the AUC_0→t, AUC_0→∞, and C _max of N-oxide VOR were decreased significantly. Incorporation of all the results indicated that both drugs had a inhibitory effect on each other's metabolism in vitro and in vivo.Conclusion: Thus, it is of great value to monitor the concomitant use of IMA and VOR in the clinic to reduce the risks of unexpected clinical outcomes.

Mutations in the breakpoint cluster region-Abelson murine leukemia 1 gene in Brazilian patients with chronic myeloid leukemia

Introduction

Mutations in the breakpoint cluster region-Abelson murine leukemia 1 gene are the leading cause of resistance to treatment with tyrosine kinase inhibitors in chronic myeloid leukemia patients. Mutations have been detected throughout the extension of the kinase domain of this gene and it is important to investigate their positions because there may be a difference in clinical relevance.

Objective

To evaluate mutations in the transcripts of the BCR-ABL1 gene in Brazilian patients with chronic myeloid leukemia under tyrosine kinase inhibitor treatment in the Hospital de Clínicas of the Universidade Federal do Paraná.

Methods

This retrospective observational cross-sectional study analyzed mutation data of BCR-ABL1 gene transcripts. Three hundred and thirty peripheral blood samples from 193 patients were evaluated with the search for mutations being achieved by Sanger sequencing.

Results

Sixteen mutation types were identified in 48/193 (24.87%) patients with T315I (20.83%) being the most common. Furthermore, four polymorphisms (T240T, K247R, E275E and Y275Y) were identified. The highest incidence of mutations (19/53: 35.85%) occurred in the P-loop of the tyrosine kinase domain, whereas no mutation was found in the A-loop. In 43/48 (89.58%) patients only one mutation was found and more than one mutation was found in 5/48 (10.42%). The simultaneous presence of two mutations (E189G/V299L and E255K/T315I) was observed in 2/5 patients while the different mutations were seen in sequential samples of the other three patients (Y253Y/T315I, T315I/E255K and E255K/T315I).

Conclusions

This molecular characterization contributed to the identification of the resistance profile to tyrosine kinase inhibitors in Brazilian patients, thus enabling the use of adequate therapeutic strategies in a timely manner.

CDA gene silencing regulated the proliferation and apoptosis of chronic myeloid leukemia K562 cells

Background

As a disease of hematopoietic stem cell, chronic myeloid leukemia (CML) possesses unique biological and clinical features. However, the biologic mechanism underlying its development remains poorly understood. Thus, the objective of the present study is to discuss the effect of cytidine deaminase (CDA) gene silencing on the apoptosis and proliferation of CML K562 cells.

Methods

CDA mRNA expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and enzymatic activity of CDA was measured by a nuclide liquid scintillation method. RT-qPCR and Western blot analysis were used to detect CDA mRNA and protein expression. Cell proliferation, apoptosis and cell cycle were measured by CCK-8 assay and flow cytometry. The expression of proteins relevant to cell proliferation, apoptosis and cell cycle was measured by Western blot analysis. Tumor xenografts were implanted in nude mice to verify the effect of CDA silencing on tumor growth in vivo.

Results

CML and AL patients showed increased mRNA expression and enzymatic activity of CDA. Compared with the blank group, the mRNA and protein expression of CDA in the shRNA-1 and shRNA-2 groups decreased significantly. As a result, the proliferation of K562 cells was inhibited after CDA silencing and the cells were mainly arrested in S and G2 phases, while the apoptosis rate of these cells was increased. In addition, CDA gene silencing in K562 cells led to down-regulated p-ERK1/2, t-AKT, p-AKT and BCL-2 expression and up-regulated expression of P21, Bax, cleaved caspase-3/total caspase-3 and cleaved PARP/total PARP. Finally, CDA gene silencing inhibited tumor growth.

Conclusion

Our study demonstrated that CDA gene silencing could inhibit CML cell proliferation and induce cell apoptosis. Therefore, CDA gene silencing may become an effective target for the treatment of leukemia.

Nanoparticles-Emerging Potential for Managing Leukemia and Lymphoma

Nanotechnology has become a powerful approach to improve the way we diagnose and treat cancer. In particular, nanoparticles (NPs) possess unique features for enhanced sensitivity and selectivity for earlier detection of circulating cancer biomarkers. In vivo, NPs enhance the therapeutic efficacy of anticancer agents when compared with conventional chemotherapy, improving vectorization and delivery, and helping to overcome drug resistance. Nanomedicine has been mostly focused on solid cancers due to take advantage from the enhanced permeability and retention (EPR) effect experienced by tissues in the close vicinity of tumors, which enhance nanomedicine's accumulation and, consequently, improve efficacy. Nanomedicines for leukemia and lymphoma, where EPR effect is not a factor, are addressed differently from solid tumors. Nevertheless, NPs have provided innovative approaches to simple and non-invasive methodologies for diagnosis and treatment in liquid tumors. In this review, we consider the state of the art on different types of nanoconstructs for the management of liquid tumors, from preclinical studies to clinical trials. We also discuss the advantages of nanoplatforms for theranostics and the central role played by NPs in this combined strategy.

PIM-1 kinase inhibitor SMI-4a exerts antitumor effects in chronic myeloid leukemia cells by enhancing the activity of glycogen synthase kinase 3β

The development of targeted tyrosine kinase inhibitors (TKIs) has succeeded in altering the course of chronic myeloid leukemia (CML). However, a number of patients have failed to respond or experienced disease relapse following TKI treatment. Proviral integration site for moloney murine leukemia virus-1 (PIM-1) is a serine/threonine kinase that participates in regulating apoptosis, cell cycle, signal transduction and transcriptional pathways, which are associated with tumor progression, and poor prognosis. SMI-4a is a selective PIM-1 kinase inhibitor that inhibits PIM-1 kinase activity in vivo and in vitro. The present study aimed to explore the mechanism underlying the antitumor effect of SMI-4a in K562 and imatinib-resistant K562 (K562/G) cell lines. It was demonstrated that SMI-4a inhibited the proliferation of K562 and K562/G cells using a WST-8 assay. The Annexin V-propidium iodide assay demonstrated that SMI-4a induced apoptosis of K562 and K562/G cells in a dose-, and time-dependent manner. Furthermore, Hoechst 33342 staining was used to verify the apoptosis rate. The clone formation assay revealed that SMI-4a significantly inhibited the colony formation capacity of K562 and K562/G cells. Western blot analysis demonstrated that SMI-4a decreased phosphorylated (p)-Ser9-glycogen synthase kinase (GSK) 3β/pGSK3β and inhibited the translocation of β-catenin. In addition, the downstream gene expression of apoptosis regulator Bax and poly(ADP-ribose) polymerase-1 was upregulated, and apoptosis regulator Bcl-2 and Myc proto-oncogene protein expression levels were downregulated. Immunofluorescence results demonstrated changes in the expression level of β-catenin in the plasma and nucleus. The results of the present study suggest that SMI-4a is an effective drug to use in combination with current chemotherapeutics for the treatment of imatinib-resistant CML.

Chronic Myeloid Leukemia in the Era of Tyrosine Kinase Inhibitors: An Evolving Paradigm of Molecularly Targeted Therapy

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm, characterized by the unrestrained expansion of pluripotent hematopoietic stem cells. CML was the first malignancy in which a unique chromosomal abnormality was identified and a pathophysiologic association was suggested. The hallmark of CML is a reciprocal chromosomal translocation between the long arms of chromosomes 9 and 22, t(9; 22)(q34; q11), creating a derivative 9q+ and a shortened 22q-. The latter, known as the Philadelphia (Ph) chromosome, harbors the breakpoint cluster region-abelson (BCR-ABL) fusion gene, encoding the constitutively active BCR-ABL tyrosine kinase that is necessary and sufficient for initiating CML. The successful implementation of tyrosine kinase inhibitors (TKIs) for the treatment of CML remains a flagship for molecularly targeted therapy in cancer. TKIs have changed the clinical course of CML; however, some patients nonetheless demonstrate primary or secondary resistance to such therapy and require an alternative therapeutic strategy. Therefore, the assessment of early response to treatment with TKIs has become an important tool in the clinical monitoring of CML patients. Although mutations in the BCR-ABL have proven to be the most prominent mechanism of resistance to TKIs, other mechanisms-either rendering the leukemic cells still dependent on BCR-ABL activity or supporting oncogenic properties of the leukemic cells independent of BCR-ABL signaling-have been identified. This article provides an overview of the current understanding of CML pathogenesis; recommendations for diagnostic tools, treatment strategies, and management guidelines; and highlights the BCR-ABL-dependent and -independent mechanisms that contribute to the development of resistance to TKIs.

Influence of MDR1 and CYP3A5 genetic polymorphisms on trough levels and therapeutic response of imatinib in newly diagnosed patients with chronic myeloid leukemia

Polymorphisms in genes coding for imatinib transporters and metabolizing enzymes may affect imatinib pharmacokinetics and clinical response. Aim of this study was to assess the influence of polymorphisms in MDR1 and CYP3A5 genes on imatinib trough levels, cytogenetic and molecular response in patients with CML. Newly diagnosed patients with chronic-phase CML started on imatinib therapy were enrolled and followed up prospectively for 24 months. The following single nucleotide polymorphisms were genotyped; C1236T, C3435T, G2677T/A in MDR1 gene and A6986G in CYP3A5 gene. Genotyping was done using PCR-RFLP method and validated by direct gene sequencing. Trough levels of imatinib were measured using LC-MS/MS. Cytogenetic response was assessed by conventional bone-marrow cytogenetics. Molecular response was assessed by qRTPCR using international scale. A total of 173 patients were included, out of which 71 patients were imatinib responders, while 102 were non-responders. Marked inter-individual variability in trough levels of imatinib was seen. Patients with GG genotype for CYP3A5-A6986G (P=0.016) and TT genotype for MDR1-C3435T (P=0.013) polymorphisms had significantly higher trough levels of imatinib. Patients with AA genotype for CYP3A5-A6986G [RR=1.448, 95% CI (1.126, 1.860), P=0.029] and CC genotype for MDR1-C1236T [RR=1.397, 95% CI (1.066, 1.831), P=0.06] &MDR1-C3435T [RR=1.508, 95% CI (1.186, 1.917), P=0.018] polymorphisms were at high risk for failure of imatinib therapy. Patients with CGC haplotype for MDR1 polymorphisms had significantly lower imatinib trough levels and were at a higher risk of imatinib failure [RR=1.547, 95% CI (1.324, 1.808), P<0.001]. GG vs. non-GG genotype for CYP3A5-A6986G [adjusted OR: 0.246; 95% CI (0.116, 0.519); P<0.001] and TT vs. non-TT genotype for MDR1-C1236T [adjusted OR: 0.270; 95% CI (0.110, 0.659); P=0.004] &MDR1-C3435T [adjusted OR: 0.289; 95% CI (0.135, 0.615); P=0.001] polymorphisms were independent factors predicting imatinib response in multivariate analysis. To conclude, MDR1 and CYP3A5 genetic polymorphisms significantly influence plasma trough levels and therapeutic response of imatinib in patients with CML. Genotyping of these polymorphisms could be of value to individualize the therapy and optimize the clinical outcomes.

Non-invasive imaging of retinal blood flow in myeloproliferative neoplasms

PURPOSE

To study the circulation in the retinal vessels in patients with blood dyscrasia due to myeloproliferative neoplasms using non-invasive retinal imaging.

METHODS

Prospective consecutive case series of seven treatment-naïve patients with chronic myeloid leukaemia (n = 2), polycythemia vera (n = 4), essential thrombocytosis (n = 1) examined before and after cytoreductive treatment. We investigated retinal circulation with motion-contrast imaging, retinal oximetry and spectral-domain optical coherence tomography.

RESULTS

Retinal venous blood velocity increased by 8.14% (CI₉₅ 3.67% to 12.6%, p = 0.004) and retinal arterial oxygen saturation increased by 7.23% (CI₉₅ 2.9% to 11.6%, p = 0.010) at follow-up (mean 12 weeks, range 5-14 weeks) where complete haematological remission had been achieved by cytoreductive treatment. Abnormal optical coherence tomography reflectivity patterns were present at baseline in patients with chronic myeloid leukaemia and were replaced by normal patterns at follow-up. Retinopathy, in the form of cotton-wool spots and retinal haemorrhages, was found at presentation in the two patients with chronic myeloid leukaemia and in one patient with polycythemia vera. The retinopathy had resolved at follow-up in all patients.

CONCLUSION

With non-invasive retinal imaging, we were able to demonstrate increased retinal venous blood velocity, increased retinal arterial blood oxygenation and normalization of intravascular reflectivity patterns after successful treatment of myeloproliferative neoplasms. Larger prospective studies are needed to assess the prognostic value of these non-invasive imaging methods in predicting circulatory complications in myeloproliferative neoplasms.

Allogeneic Transplantation in Chronic Myeloid Leukemia and the Effect of Tyrosine Kinase Inhibitors on Survival: A Quasi-Experimental Study

Objective:

Tyrosine kinase inhibitors (TKIs) have changed the indications for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in chronic myeloid leukemia (CML). Therefore, we aimed to evaluate the effect of TKIs on allo-HSCT in CML.

Materials and Methods:

In this quasi-experimental study, we compared patient, disease, and transplantation characteristics as well as allo-HSCT outcomes between the pre-TKI era (before 2002) and the post-TKI era (2002 and later) in patients with CML. A total of 193 allo-HSCTs were performed between 1989 and 2012.

Results:

Patients in the post-TKI era had more advanced disease (>chronic phase 1) at the time of transplant and more frequently received reduced-intensity conditioning compared to patients in the pre-TKI era. Relapse/progression occurred more frequently in the year ≥2002 group than in the year <2002 group (48% vs. 32% at 5 years, p=0.01); however, overall survival (OS) was similar in these two groups (5-year survival was 50.8% vs. 59.5%, respectively; p=0.3). TKIs (with donor lymphocyte infusions or alone) for treatment of relapse after allo-HSCT were available in the post-TKI era and were associated with improved OS. While the rates of hematologic remission at 3 months after allo-HSCT were similar between TKI eras, patients having remission had better disease-free survival (DFS) [relative risk (RR): 0.15, confidence interval (CI) 95%: 0.09-0.24, p<0.001] and OS (RR: 0.14, CI 95%: 0.09-0.23, p<0.001). Male allo-HSCT recipients had worse DFS (RR: 1.7, CI 95%: 1.2-2.5, p=0.007) and OS (RR: 1.7, CI 95%: 1.1-2.6, p=0.02) than females.

Conclusion:

TKIs are an effective option for the treatment of relapse after allo-HSCT in CML. Hematologic remission after allo-HSCT is also an important factor for survival in CML patients.

Current trends in molecular diagnostics of chronic myeloid leukemia

Nearly 1.5 million people worldwide suffer from chronic myeloid leukemia (CML), characterized by the genetic translocation t(9;22)(q34;q11.2), involving the fusion of the Abelson oncogene (ABL1) with the breakpoint cluster region (BCR) gene. Early onset diagnosis coupled to current therapeutics allow for a treatment success rate of 90, which has focused research on the development of novel diagnostics approaches. In this review, we present a critical perspective on current strategies for CML diagnostics, comparing to gold standard methodologies and with an eye on the future trends on nanotheranostics.

Increase of T and B cells and altered BACH2 expression patterns in bone marrow trephines of imatinib-treated patients with chronic myelogenous leukaemia

The effect of imatinib on T and B cells in patients with chronic myelogenous leukaemia (CML) is not well understood. An upregulation of the transcription factor Broad-complex-Tramtrack-Bric-a-Brac and Cap‘n’collar 1 bZip transcription factor 2 (BACH2), which is involved in the development and differentiation of B cells, was demonstrated in a CML cell line treated with imatinib. The present study retrospectively analysed the expression and distribution of cluster of differentiation (CD)3, CD20 and BACH2 (per 1,000 cells), as well as the co-expression of CD20 and BACH2, using immunohistochemistry in serial bone marrow trephines obtained from 14 CML patients treated with imatinib in comparison to 17 patients with newly diagnosed CML and 6 control trephines. Bone marrow trephines of CML patients in remission under imatinib therapy exhibited significantly higher numbers of CD3 and CD20 infiltrates (partly ordered in aggregates) compared with patients with newly diagnosed CML and control individuals. Similarly, nuclear expression of BACH2 in granulopoietic cells was increased in CML patients treated with imatinib, which may represent the histological correlate of the positive treatment effect. Furthermore, since BACH2 is involved in B cell development, its altered expression patterns by imatinib may be one explanation for high B cell numbers, as revealed by CD20/BACH2 (nuclear)-positive cells. As the present data are preliminary, future prospective studies are required to assess the prognostic and predictive role of BACH2 in patients with CML under targeted therapy.

Biophysical differences between chronic myelogenous leukemic quiescent and proliferating stem/progenitor cells

The treatment of chronic myeloid leukemia (CML), a clonal myeloproliferative disorder has improved recently, but most patients have not yet been cured. Some patients develop resistance to the available tyrosine kinase treatments. Persistence of residual quiescent CML stem cells (LSCs) that later resume proliferation is another common cause of recurrence or relapse of CML. Eradication of quiescent LSCs is a promising approach to prevent recurrence of CML. Here we report on new biophysical differences between quiescent and proliferating CD34+ LSCs, and speculate how this information could be of use to eradicate quiescent LSCs. Using AFM measurements on cells collected from four untreated CML patients, substantial differences are observed between quiescent and proliferating cells in the elastic modulus, pericellular brush length and its grafting density at the single cell level. The higher pericellular brush densities of quiescent LSCs are common for all samples. The significance of these observations is discussed.

Computational analysis of binding between benzamide-based derivatives and Abl wt and T315I mutant kinases

An integrated computational study was performed to identify the binding mechanisms of benzamide-based derivatives with Abl_wt/Abl_T315I kinases for designing Abl inhibitors.

Expression of the ETS transcription factor GABPα is positively correlated to the BCR-ABL1/ABL1 ratio in CML patients and affects imatinib sensitivity in vitro

In Philadelphia-positive chronic myeloid leukemia (CML), imatinib resistance frequently emerges because of point mutations in the ABL1 kinase domain, but may also be the consequence of uncontrolled upstream signaling. Recently, the heteromeric transcription factor GA-binding protein (GABP) was found to promote CML-like myeloproliferative disease in mice. In a cohort of 70 CML patients, we found that expression of the GABP α subunit (GABPα) is positively correlated to the BCR-ABL1/ABL1 ratio. Moreover, significantly higher GABPα expression was detected in blast crisis than in chronic phase CML after performing data mining on 91 CML patients. In functional studies, imatinib sensitivity is enhanced after GABPα knockdown in tyrosine kinase inhibitors (TKI)-sensitive K-562, as well as by overexpression of a deletion mutant in TKI-resistant NALM-1 cells. Moreover, in K-562 cells, GABP-dependent expression variations of PRKD2 and RAC2, relevant signaling mediators in CML, were observed. Notably, protein kinase D2 (Prkd2) was reported to be a GABP target gene in mice. In line with this, we detected a positive correlation between GABPA and PRKD2 expression in primary human CML, indicating that the effects of GABP are mediated by PRKD2. These findings illustrate an important role for GABP in disease development and imatinib sensitivity in human CML.

A new internet-based tool for reporting and analysing patient-reported outcomes and the feasibility of repeated data collection from patients with myeloproliferative neoplasms

PURPOSE

An Internet-based tool for reporting and analysing patient-reported outcomes (PROs) has been developed. The tool enables merging PROs with blood test results and allows for computation of treatment responses. Data may be visualized by graphical analysis and may be exported for downstream statistical processing. The aim of this study was to investigate, whether patients with myeloproliferative neoplasms (MPNs) were willing and able to use the tool and fill out questionnaires regularly.

METHODS

Participants were recruited from the outpatient clinic at the Department of Haematology, Roskilde University Hospital, Denmark. Validated questionnaires that were used were European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, Myeloproliferative Neoplasm Symptom Assessment Form, Brief Fatigue Inventory and Short Form 36 Health Survey. Questionnaires were filled out ≥ 6 months online or on paper according to participant preference. Regularity of questionnaire submission was investigated, and participant acceptance was evaluated by focus-group interviews.

RESULTS

Of 135 invited patients, 118 (87 %) accepted participation. One hundred and seven participants (91 %) preferred to use the Internet-based tool. Of the 118 enrolled participants, 104 (88 %) submitted PROs regularly ≥ 6 months. The focus-group interviews revealed that the Internet-based tool was well accepted.

CONCLUSION

The Internet-based approach and regular collection of PROs are well accepted with a high participation rate, persistency and adherence in a population of MPN patients. The plasticity of the platform allows for adaptation to patients with other medical conditions.

Glioblastoma multiforme: Pathogenesis and treatment

Each year, about 5-6 cases out of 100,000 people are diagnosed with primary malignant brain tumors, of which about 80% are malignant gliomas (MGs). Glioblastoma multiforme (GBM) accounts for more than half of MG cases. They are associated with high morbidity and mortality. Despite current multimodality treatment efforts including maximal surgical resection if feasible, followed by a combination of radiotherapy and/or chemotherapy, the median survival is short: only about 15months. A deeper understanding of the pathogenesis of these tumors has presented opportunities for newer therapies to evolve and an expectation of better control of this disease. Lately, efforts have been made to investigate tumor resistance, which results from complex alternate signaling pathways, the existence of glioma stem-cells, the influence of the blood-brain barrier as well as the expression of 0(6)-methylguanine-DNA methyltransferase. In this paper, we review up-to-date information on MGs treatment including current approaches, novel drug-delivering strategies, molecular targeted agents and immunomodulative treatments, and discuss future treatment perspectives.

Isolated central nervous system relapse in chronic myeloid leukemia

Chronic myeloid leukemia is a myeloproliferative disorder that has three distinguished phases: chronic, accelerated, and blastic. In extremely rare cases, the blast phase can affect the central nervous system without concomitant bone marrow involvement. We report the case of a patient with chronic myeloid leukemia who, despite having achieved complete cytogenetic remission in the bone marrow for several years, experienced a blast crisis of the central nervous system following an episode of infectious meningoencephalitis.

Future translational applications from the contemporary genomics era: a scientific statement from the American Heart Association

The field of genetics and genomics has advanced considerably with the achievement of recent milestones encompassing the identification of many loci for cardiovascular disease and variable drug responses. Despite this achievement, a gap exists in the understanding and advancement to meaningful translation that directly affects disease prevention and clinical care. The purpose of this scientific statement is to address the gap between genetic discoveries and their practical application to cardiovascular clinical care. In brief, this scientific statement assesses the current timeline for effective translation of basic discoveries to clinical advances, highlighting past successes. Current discoveries in the area of genetics and genomics are covered next, followed by future expectations, tools, and competencies for achieving the goal of improving clinical care.

Co-operating STAT5 and AKT signaling pathways in chronic myeloid leukemia and mastocytosis: possible new targets of therapy

Chronic myeloid leukemia and systemic mastocytosis are myeloid neoplasms sharing a number of pathogenetic and clinical features. In both conditions, an aberrantly activated oncoprotein with tyrosine kinase activity, namely BCR-ABL1 in chronic myeloid leukemia, and mutant KIT, mostly KIT D816V, in systemic mastocytosis, is key to disease evolution. The appreciation of the role of such tyrosine kinases in these diseases has led to the development of improved therapies with tyrosine kinase-targeted inhibitors. However, most drugs, including new KIT D816V-blocking agents, have failed to achieve long-lasting remissions in advanced systemic mastocytosis, and there is a similar problem in chronic myeloid leukemia, where imatinib-resistant patients sometimes fail to achieve remission, even with second- or third-line BCR-ABL1 specific tyrosine kinase inhibitors. During disease progression, additional signaling pathways become activated in neoplastic cells, but most converge into major downstream networks. Among these, the AKT and STAT5 pathways appear most critical and may result in drug-resistant chronic myeloid leukemia and systemic mastocytosis. Inhibition of phosphorylation of these targets has proven their crucial role in disease-evolution in both malignancies. Together, these observations suggest that STAT5 and AKT are key drivers of oncogenesis in drug-resistant forms of the diseases, and that targeting STAT5 and AKT might be an interesting approach in these malignancies. The present article provides an overview of our current knowledge about the critical role of AKT and STAT5 in the pathophysiology of chronic myeloid leukemia and systemic mastocytosis and on their potential value as therapeutic targets in these neoplasms.

Chronic myeloid leukaemia

In less than 10 years, the prognosis of chronic myeloid leukaemia has changed from that of a fatal disease to a disorder amenable simply to lifelong oral medication and compatible with a normal lifespan. This change has been made possible by a deep understanding of the molecular pathogenesis and a determination to develop targeted and selective drugs. This Seminar summarises the presentation, pathophysiology, diagnosis and monitoring technology, treatment options, side-effects, and outcomes of chronic myeloid leukaemia, and discusses the possibility of cure-ie, stable undetectable or low level disease in the absence of medication. Chronic myeloid leukaemia continues to instruct us in the mechanisms of leukaemogenesis and provides hope not only for similar developments in management of other malignancies, but also for the remarkable speed with which these can move from bench to bedside.

Personalized medicine and the clinical laboratory

Personalized medicine is the use of biomarkers, most of them molecular markers, for detection of specific genetic traits to guide various approaches for preventing and treating different conditions. The identification of several genes related to heredity, oncology and infectious diseases lead to the detection of genetic polymorphisms that are involved not only in different clinical progression of these diseases but also in variations in treatment response. Currently, it is possible to detect these polymorphisms using several methodologies: detection of single nucleotide polymorphisms using polymerase chain reaction methods; nucleic acid microarray detection; and nucleic acid sequencing with automatized DNA sequencers using Sanger-derived methods and new generation sequencing. Personalized medicine assays are directed towards detecting genetic variations that alter interactions of drugs with targets or the metabolic pathways of drugs (upstream and downstream) and can be utilized for the selection of drug formulations and detect different immunogenicities of the drug. Personalized medicine applications have already been described in different areas of Medicine and allow specific treatment approaches to be applied to each patient and pathology according to the results of these assays. The application of such a protocol demands an increasing interaction between the clinical laboratory and the clinical staff. For its implementation, a coordinated team composed of basic researchers and physicians highly specialized in their areas supported by a highly specialized team of clinical analysts particularly trained in molecular biology assays is necessary.

[Generation and identification of P210(T315I-BCR/ABL) transgenic mice]

OBJECTIVE

To construct the P210(T315I-BCR/ABL) transgenic mice model.

METHODS

The transgenic vector in which the P210(T315I-BCR/ABL) gene and eGFP gene was derived by APN/CD13 promoter was constructed and microinjected into the single-cell fertilized eggs of C57 mice. Transgene integration was conformed by PCR genotyping and P210(T315I-BCR/ABL) expression levels was evaluated by RT-PCR. The CML phenotype was confirmed by blood routine examination, Wright's staining for peripheral blood and bone marrow smears, HE staining for organs of transgenic mice.

RESULTS

Three transgenic mice lines with high expression of P210(T315I-BCR/ABL) gene and eGFP gene was selected. Compared with the wild type mice, the levels of WBC, platelet and neutrophil granulocyte of transgenic mice began to increase gradually at 2 months, and increase to 23.9×10⁹/L, 4 136×10⁹/L, and 74.6% respectively at 6 months. The remarkable hyperplasia of granulocytes was seen in the peripheral blood and bone marrow smears with splenomegaly infiltrated by leukemic cells.

CONCLUSION

The P210(T315I-BCR/ABL) transgenic mice was constructed and provided a model to explore the mechanism of T315I CML and screen out the drug for T315 CML patient.

A coiled-coil mimetic intercepts BCR-ABL1 dimerization in native and kinase-mutant chronic myeloid leukemia

Targeted therapy of chronic myeloid leukemia is currently based on small-molecule inhibitors that directly bind the tyrosine kinase domain of BCR-ABL1. This strategy has generally been successful, but is subject to drug resistance due to point mutations in the kinase domain. Kinase activity requires transactivation of BCR-ABL1 following an oligomerization event, which is mediated by the coiled-coil (CC) domain at the N-terminus of the protein. Here, we describe a rationally engineered mutant version of the CC domain, called CC^mut3, which interferes with BCR-ABL1 oligomerization and promotes apoptosis in BCR-ABL1-expressing cells, regardless of kinase domain mutation status. CC^mut3 exhibits strong pro-apoptotic and anti-proliferative activity in cell lines expressing native BCR-ABL1, single kinase domain mutant BCR-ABL1 (E255V and T315I) or compound mutant BCR-ABL1 (E255V/T315I). Moreover, CC^mut3 inhibits colony formation by primary CML CD34⁺ cells ex vivo, including a sample expressing the T315I mutant. These data suggest that targeting BCR-ABL1 with CC mutants may provide a novel alternative strategy for treating patients with resistance to current targeted therapies.

Emergence of BCR-ABL kinase domain mutations associated with newly diagnosed chronic myeloid leukemia: a meta-analysis of clinical trials of tyrosine kinase inhibitors

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are a mainstay of treatment for patients suffering from chronic myeloid leukemia (CML). Testing for various mutations in the BCR-ABL gene may help predict lack of response to specific TKIs where resistance has developed.

OBJECTIVE

To estimate the emergence of BCR-ABL kinase domain mutations associated with newly diagnosed CML patients exposed to first-line TKI treatment.

METHODS

Published studies were identified using a structured search of online databases. Original research studies were included if they reported the incidence of specific BCR-ABL kinase domain point mutations after first-line TKI treatment failure or baseline mutations for second-line TKI treatment following first-line treatment failure. Meta-analysis of mutation rates across studies was based on DerSimonian and Laird's random-effects model.

RESULTS

Of 1,323 citations, 12 studies met the inclusion criteria, involving a total of 1,698 patients. Overall mutation rates (95% CI) were imatinib 9.7% (6.2%-13.3%); dasatanib 1.7% (0.0%-4.3%); and nilotinib 3.3% (0.0%-7.7%). The most common specific mutations were T315I, E255K, and M351T. T315I mutations constituted 58% (7 of 12) of dasatinib-related mutations and 13% (15 of 117) of imatinib-related mutations.

CONCLUSIONS

Lack of response to TKIs associated with mutation in the BCR-ABL gene was significantly higher in imatinib-treated patients, and all mutations arose after treatment. T315I was a common treatment-emergent mutation. Further research is needed to assess the prognostic value of testing for mutations and the economic implications of treatment-emergent mutations.

Treatment patterns and prognostic indicators of response to therapy among patients with chronic myeloid leukemia in Australia, Canada, and South Korea

OBJECTIVE

Given the multiple options for treatment of chronic-phase chronic myeloid leukemia (CML) with tyrosine kinase inhibitors, our objective was to understand treatment patterns in routine practice and prognostic indicators of response.

RESEARCH DESIGN AND METHODS

We conducted a retrospective medical record review of 681 patients with CML in Australia, Canada, and South Korea. Eligible patients had a diagnosis of chronic-phase CML, were Philadelphia chromosome and/or BCR-ABL positive, were aged 18 years or older, and had been treated with first-line imatinib therapy between January 2005 and September 2010. Data on patient demographics, medical history (e.g., comorbidities, Sokal score), and treatment characteristics (e.g., time to initiation, therapy duration) were abstracted. Descriptive analyses were stratified by country and therapy line. Prognostic indicators of response to imatinib were evaluated using multivariable logistic regression, adjusting for country, patient demographics, medical history, treatment characteristics, and side effects.

MAIN OUTCOME MEASURES

Hematologic, cytogenetic, and molecular responses at 3, 6, 12, and 18 months following initiation of each therapy line.

RESULTS

Patients' average age was 57 years, and 59% were male. Overall, imatinib was initiated approximately 4 months following CML diagnosis. Complete or major molecular response (C/MMR) at 6 months following imatinib initiation was 54% in Australia, 22% in Canada, and 38% in South Korea. At 18 months, over 60% of patients achieved C/MMR. Approximately 30% of patients discontinued imatinib primarily due to intolerance and lack of response. Among patients who received second-line treatment, dasatinib was used more frequently than nilotinib. Multivariable regression results indicated Sokal score was identified as a prognostic indicator of response to imatinib therapy at several time points.

LIMITATIONS

There are several limitations to this study. First, we selected a convenience sample of patients and physicians and therefore results may not be representative of the true population of patients with chronic-phase CML. Second, data were entered by the selected physician and could be subject to data entry errors or inaccuracies. Third, limited information was collected from the patient records, and it is possible that we did not capture additional prognostic or confounding factors related to the measured outcomes. Next, because this was an analysis of previously documented data (i.e., retrospective), we were unable to provide a priori definitions of response. Finally, multivariable analyses were limited to imatinib-related outcomes.

CONCLUSIONS

Treatment patterns and prognostic indicators differed by country. Health care providers, payers, and patients can utilize these results to inform treatment and policies aimed at improving the effectiveness of care for patients with chronic-phase CML.

IGFBP-2 - taking the lead in growth, metabolism and cancer

The activity of the Insulin-like Growth Factors (IGFs) ligands elicited via their receptors and transduced by various intracellular signal pathways is modulated by the IGF Binding Proteins (IGFBPs). Among all the IGFBPs, IGFBP-2 has been implicated in the regulation of IGF activity in most tissue and organs. Besides binding to IGFs in the circulation these IGF-regulatory activities of IGFBP-2 involve interactions with components of the extracellular matrix, cell surface proteoglycans and integrin receptors. In addition to these local peri-cellular activities, IGFBP-2 exerts other key functions within the nucleus, where IGFBP-2 directly or indirectly promotes transcriptional activation of specific genes. All of these IGFBP-2 activities, intrinsic or dependent on IGFs, contribute to its functional roles in growth/development, metabolism and malignancy as evidenced by studies in IGFBP-2 animal models and also by many in vitro studies. Finally, preclinical studies have demonstrated that IGFBP-2 administration can be beneficial in improving metabolic responses (inhibition of adipogenesis and enhanced insulin sensitivity), while blockade of IGFBP-2 appears to be an effective approach to inhibiting tumour growth and metastasis.

Adverse skeletal effects of drugs - beyond Glucocorticoids

Osteoporotic fractures are an important public health problem with significant individual and societal costs. In addition to the major risk factors for osteoporotic fracture, low bone mineral density (BMD), age, low body weight and history of fracture or falls, some drugs are now considered to be important secondary risk factor for bone loss and fracture, particularly amongst predisposed individuals. Currently available data are often generated from small observational clinical studies, making risk assessment and development of management guidelines difficult. In many cases, the exposed population has a low baseline risk for fracture and additional assessment and treatment may not be necessary. In this review, we focus on drugs other than glucocorticoids identified as potentially causing adverse skeletal effects, summarizing the existing evidence from preclinical and clinical studies, and suggest recommendations for patient management.

MDR1 gene polymorphisms and imatinib response in chronic myeloid leukemia: a meta-analysis

BACKGROUND

MDR1 gene polymorphisms were demonstrated to be associated with interindividual variability of imatinib response for chronic myeloid leukemia (CML) patients in several studies; however, the results have been inconclusive.

MATERIALS & METHODS

To clarify the effect of common MDR1 variants on clinical response to imatinib, we performed a meta-analysis to quantify the accumulated information from genetic association studies. After a thorough search of the published literature, we undertook a meta-analysis to evaluate the effect of MDR1 C1236T, G2677T and C3435T polymorphisms on imatinib response.

RESULTS

Our pooled data showed a significant association between MDR1 C1236T polymorphism and the increasing risk of imatinib resistance in Asian CML patients. However, no significant association was found for the MDR1 G2677T or C3435T polymorphisms in an Asian CML population as well as a Caucasian CML population.

CONCLUSION

The synonymous MDR1 C1236T polymorphism might be a risk factor for nonoptimal clinical response to imatinib in Asian CML patients.