Targeted therapy in chronic myeloid leukemia

Synthesis and in vitro evaluation of self-assembling biocompatible heparin-based targeting polymeric micelles for delivery of doxorubicin to leukemic cells

Background and purpose

Biodegradable polymeric micelles have emerged as one of the most promising platforms for targeted drug delivery. In the present study, a polymeric micelle composed of folic acid (FA), heparin (HEP), dexamethasone (DEX), and (FA-PEG-HEP-CA-TOC) was developed for the delivery of doxorubicin (DOX) to leukemic cells.

Experimental approach

FA-HEP-DEX was synthesized and characterized by 1H-NMR. DOX-loaded micelles were prepared using a dialysis method. The impact of various processing variables, including polymer-to-drug ratio, dialysis temperature, and solvent type, on the physicochemical properties of the micelles were evaluated. In vitro, cellular uptake and cytotoxicity of the micelles in folate receptor-positive (K562) and negative (HepG2) cells were evaluated.

Findings/Results

The 1H-NMR results confirmed the successful synthesis of FA-HEP-DEX. DOX-loaded micelles exhibited an average particle size of 117 to 181 nm with a high drug entrapment efficiency (36% to 71%). DOX-loaded micelles also showed sustained drug-release behavior. DOX-loaded FA-HEP-DEX micelles exhibited higher cellular uptake and in vitro cytotoxicity than free DOX and DOX-loaded HEP-DEX micelles in K562 cells.

Conclusions and implications

DOX was well incorporated into the micelles with high entrapment efficiency due to high solubility of DOX in DEX as the hydrophobic component of the micelle structure. The higher cellular uptake and cell toxicity of targeted micelles correspond to the presence of FA on the micelle surface, which promotes cell internalization of the micelles viaspecific receptor-mediated endocytosis. Our results indicated the potential of DOX-loaded heparin-based micelles with desirable antitumor activity as a targeted drug delivery system in cancer therapy.

Virtual Screening, Molecular Docking, and Dynamic Simulations Revealed TGF-β1 Potential Inhibitors to Curtail Cervical Cancer Progression

Cervical cancer is one of the main causes of cancer death in women globally, and its epidemiology is similar to that of a low-infectious venereal illness. Many sexual partners and early age at first intercourse have been demonstrated to have a significant influence on risk. TGF-β1 is a multifunctional cytokine that is required for cervical carcinoma metastasis, tumor development, progression, and invasion. The TGF-β1 signaling system plays a paradoxical function in cancer formation, suppressing early-stage tumor growth while increasing tumor progression and metastasis. Importantly, TGF-β1 and TGF-β receptor 1 (TGF-βR1), two components of the TGF-β signaling system, are substantially expressed in a range of cancers, including breast cancer, colon cancer, gastric cancer, and hepatocellular carcinoma. The current study aims to investigate possible inhibitors targeting TGF-β1 using molecular docking and dynamic simulations. To target TGF-β1, we used anti-cancer drugs and small molecules. MVD was utilized for virtual screening, and the highest scoring compound was then subjected to MD simulations using Schrodinger software package v2017-1 (Maestro v11.1) to identify the most favorable lead interactions against TGF-β1. The Nilotinib compound has shown the least XP Gscore of -2.581 kcal/mol, 30ns MD simulations revealing that the Nilotinib- TGF-β1 complex possesses the lowest energy of -77784.917 kcal/mol. Multiple parameters, including Root Mean Square Deviation, Root Mean Square Fluctuation, and Intermolecular Interactions, were used to analyze the simulation trajectory. Based on the results; we conclude that the ligand nilotinib appears to be a promising prospective TGF-β1inhibitor for reducing TGF-β1 expression ad halting cervical cancer progression.

Incidence, Prevalence and Real-World Treatment Patterns in Chronic Myeloid Leukemia: Results from a Population Representative German Claims Data Analysis

Introduction Real-world data on usage of 1st, 2nd and 3rd generation tyrosine kinase inhibitor (TKIs) in chronic myeloid leukemia (CML) is scarce. This study therefore aimed to analyze the use of different TKIs used in 1st- and 2nd-line treatment and the frequency of TKI switches in CML. Methods This observational study was based on the InGef research database, an anonymized representative claims dataset in Germany (n= 4 million). An incidence and prevalence patient CML cohort was followed for 5 and 3 years. Analyses regarding incidence, prevalence and therapy distribution were performed descriptively. Results 151 patients were included in the incidence and 636 patients in the prevalence cohort. This resulted in an incidence of 1.8 (95%-confidence interval [CI]: 1.34 - 2.20) and a prevalence of 14.9 (95%-CI 13.70 - 16.03) per 100,000 inhabitants. For the incidence cohort, data on 1st-line therapy was available for 124 patients and distributed across imatinib (N=52), nilotinib (N=44), dasatinib (N=12), chemotherapies as hydroxycarbamide (N=11) and ponatinib/bosutinib (N=5). 26% of patients switched TKI therapy at least once in three years. In the prevalence cohort, 423 patients (66.5%) had claims on existing or newly emerged cardiovascular diseases (CD). No significant differences (p=0.32) between TKIs in patients with CD were found. Discussion Every fourth patient switched TKI therapy within the first three years after treatment initiation. Switches were more likely when hints of disease progression or intolerability were observable in the database.

MiR-7 Functions as a Tumor Suppressor by Targeting the Oncogenes TAL1 in T-Cell Acute Lymphoblastic Leukemia

BACKGROUND

T-cell acute lymphoblastic leukemia is a hematologic malignancy characterized by T-cell proliferation, and in many cases, the ectopic expression of the oncogenic transcription factor T-cell acute lymphocytic leukemia protein 1 (TAL1). MicroRNA-7 has been shown to play a critical role in proliferation, migration, and treatment sensitivity in a diverse array of cancers. In this study, we sought to establish a novel link between microRNA-7 and T-cell acute lymphoblastic leukemia oncogenesis.

MATERIAL AND METHOD

To do so, we characterized gene expression of microRNA-7 as well as TAL1 in both T-cell acute lymphoblastic leukemia patient-derived tissue and cell lines, as well as performing functional luciferase assays to assess microRNA-7 binding to the TAL1 3'-untranslated region. We also performed growth, apoptosis, and migration experiments using 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide, Annexin V, and transwell assays in the context of microRNA-7 overexpression.

RESULTS

We found that microRNA-7 expression is attenuated and inversely correlated with TAL1 expression in TAL1 + T-cell acute lymphoblastic leukemia cells. Additionally, microRNA-7 directly targets and suppresses TAL1 levels. Finally, microRNA-7 overexpression reduces growth, motility, and migration while inducing apoptosis in T-cell acute lymphoblastic leukemia cells, phenotypes that can be rescued by concomitant overexpression of TAL1.

CONCLUSIONS

These results indicate that microRNA-7 functions as a potent tumor suppressor by inhibiting the oncogene TAL1 and suggest microRNA-7 could function as a prognostic biomarker and possible therapeutic in the clinical management of T-cell acute lymphoblastic leukemia.

Nanocarriers as Magic Bullets in the Treatment of Leukemia

Leukemia is a type of hematopoietic stem/progenitor cell malignancy characterized by the accumulation of immature cells in the blood and bone marrow. Treatment strategies mainly rely on the administration of chemotherapeutic agents, which, unfortunately, are known for their high toxicity and side effects. The concept of targeted therapy as magic bullet was introduced by Paul Erlich about 100 years ago, to inspire new therapies able to tackle the disadvantages of chemotherapeutic agents. Currently, nanoparticles are considered viable options in the treatment of different types of cancer, including leukemia. The main advantages associated with the use of these nanocarriers summarized as follows: i) they may be designed to target leukemic cells selectively; ii) they invariably enhance bioavailability and blood circulation half-life; iii) their mode of action is expected to reduce side effects. FDA approval of many nanocarriers for treatment of relapsed or refractory leukemia and the desired results extend their application in clinics. In the present review, different types of nanocarriers, their capability in targeting leukemic cells, and the latest preclinical and clinical data are discussed.

Long-term bosutinib for chronic phase chronic myeloid leukemia after failure of imatinib plus dasatinib and/or nilotinib

Bosutinib is an Src/Abl tyrosine kinase inhibitor (TKI) indicated for adults with Ph+ chronic myeloid leukemia (CML) resistant/intolerant to prior TKIs. This long-term update of an ongoing phase 1/2 study evaluated the efficacy and safety of third-/fourth-line bosutinib in adults with chronic phase (CP) CML. Median durations of treatment and follow-up were 8.6 (range, 0.2-87.7) months and 32.7 (0.3-93.3) months, respectively. Cumulative confirmed complete hematologic response (cCHR) and major cytogenetic response (MCyR) rates were 74% (95% CI, 65-81%) and 40% (31-50%), respectively; Kaplan-Meier (K-M) probability of maintaining cCHR or MCyR at 4 years was 63% (95% CI, 50-73%) and 69% (52-81%). Cumulative incidence of on-treatment disease progression (PD)/death at 4 years was 24% (95% CI, 17-33%); K-M 4-year overall survival was 78% (68-85%). Baseline Ph+ cells ≤35 vs. ≥95% was prognostic of MCyR and CCyR by 3 and 6 months, increased baseline basophils was prognostic of PD/death, and no prior response to second-line TKI was prognostic of death. Common adverse events included diarrhea (83%), nausea (48%), vomiting (38%), and thrombocytopenia (39%). Bosutinib demonstrates durable efficacy and a toxicity profile similar to previous bosutinib studies in CP CML patients resistant/intolerant to multiple TKIs, representing an important treatment option for patients in this setting. This trial is registered at www.clinicaltrials.gov (NCT00261846). Am. J. Hematol. 91:1206-1214, 2016. © 2016 Wiley Periodicals, Inc.

EphB4-VAV1 signaling pathway is associated with imatinib resistance in chronic myeloid leukemia cells

Imatinib (IM) resistant Chronic Myeloid Leukemia (CML) is an important issue to be addressed while treating CML patients. The present study analyzes the role of EphB4-VAV1 signaling in IM-resistant CML. EphB4 and VAV1 were overexpressed in IM-resistant CML patients and K562-R cell line (K562-R). Then, we established stable under-expressing EphB4 cell line K562-R-EphB4-sh. VAV1 was down-regulated in K562-R-EphB4-sh cells. K562-R-EphB4-sh cells gained re-sensitivity to IM and K562-R cells showed mild IM resistance. However, EphB4 was no changed when the VAV1 was down-regulated. EphB4 and VAV1 were overexpressed in IM-resistant CML, VAV1might be the downstream moleculars of EphB4. These results suggest a potential role of EphB4-VAV1 signaling as therapeutic target of IM-resistant CML.

Lung Cancer Genomics in the Era of Accelerated Targeted Drug Development

Lung cancer is the leading cause of cancer-related deaths in the United States and the 5-year overall survival outlook for a patient has not improved in several decades. Recently, however, molecular and genomic profiling of the lung tumors has revealed recurring somatic mutations. As a result the therapeutic landscape of lung cancer is undergoing a paradigm shift from a purely histology-based understanding of the disease to subtype distinctions based on tumor genetics, which has launched cancer-specific, mechanism-based targeted therapies with clear benefit to patients. While targeted therapy advancements are being made at an ever increasing rate, a new challenge in the form of drug resistance has also emerged. This review summarizes the current literature for these issues.

Bosutinib efficacy and safety in chronic phase chronic myeloid leukemia after imatinib resistance or intolerance: Minimum 24-month follow-up

Bosutinib is an orally active, dual Src/Abl tyrosine kinase inhibitor for treatment of chronic myeloid leukemia (CML) following resistance/intolerance to prior therapy. Here, we report the data from the 2-year follow-up of a phase 1/2 open-label study evaluating the efficacy and safety of bosutinib as second-line therapy in 288 patients with chronic phase CML resistant (n = 200) or intolerant (n = 88) to imatinib. The cumulative response rates to bosutinib were as follows: 85% achieved/maintained complete hematologic response, 59% achieved/maintained major cytogenetic response (including 48% with complete cytogenetic response), and 35% achieved major molecular response. Responses were durable, with 2-year estimates of retaining response >70%. Two-year probabilities of progression-free survival and overall survival were 81% and 91%, respectively. The most common toxicities were primarily gastrointestinal adverse events (diarrhea [84%], nausea [45%], vomiting [37%]), which were primarily mild to moderate, typically transient, and first occurred early during treatment. Thrombocytopenia was the most common grade 3/4 hematologic laboratory abnormality (24%). Outcomes were generally similar among imatinib-resistant and imatinib-intolerant patients and did not differ with age. The longer-term results of the present analysis confirm that bosutinib is an effective and tolerable second-line therapy for patients with imatinib-resistant or imatinib-intolerant chronic phase CML. http://ClinicalTrials.gov Identifier: NCT00261846. Am. J. Hematol. 89:732–742, 2014. © 2014 The Authors American Journal of Hematology Published by Wiley Periodicals, Inc.

Imatinib: a breakthrough of targeted therapy in cancer

Deregulated protein tyrosine kinase activity is central to the pathogenesis of human cancers. Targeted therapy in the form of selective tyrosine kinase inhibitors (TKIs) has transformed the approach to management of various cancers and represents a therapeutic breakthrough. Imatinib was one of the first cancer therapies to show the potential for such targeted action. Imatinib, an oral targeted therapy, inhibits tyrosine kinases specifically BCR-ABL, c-KIT, and PDGFRA. Apart from its remarkable success in CML and GIST, Imatinib benefits various other tumors caused by Imatinib-specific abnormalities of PDGFR and c-KIT. Imatinib has also been proven to be effective in steroid-refractory chronic graft-versus-host disease because of its anti-PDGFR action. This paper is a comprehensive review of the role of Imatinib in oncology.

Lack of congruence between patients' and health professionals' perspectives of adherence to imatinib therapy in treatment of chronic myeloid leukemia: A qualitative study

OBJECTIVE

Consistent use of imatinib is critical for treatment success in chronic myeloid leukemia, yet perfect adherence to the prescribed clinical regimen is reported to be as low as 14%. This study aimed to understand patients' experiences of chronic myeloid leukemia with a qualitative approach, including identified facilitators and barriers to adherence, drawing on patients' and health professionals' perspectives, recording comments made by patients and health professionals involved with the same treatment team.

METHOD

We recruited patients with chronic myeloid leukemia prescribed imatinib therapy and health professionals involved in their treatment from a specialized cancer center. Semi-structured qualitative interviews were recorded, transcribed, and manually analyzed using interpretive phenomenological analysis. Recruitment ceased upon saturation, with 16 patients and 10 health professionals (hematologists n = 4, nurses n = 3, pharmacists n = 3).

RESULTS

Twelve patients reported at least one instance of nonadherence. Reasons for unintentional nonadherence included forgetfulness related to variations of routine and doctor-patient communication issues. Reasons for intentional nonadherence included desires to reduce dose-dependent side effects and insufficient support. Patients who reported higher nonadherence rates felt complacent following periods of sustained disease control or had received conflicting advice regarding nonadherence. Health professionals had difficulty in accurately evaluating medication adherence due to a lack of reliable measures, utilizing patient self-report and manifestations of suboptimal disease control to guide assessments.

SIGNIFICANCE OF RESULTS

Adherence issues persist throughout the course of treatment. While high patient-reported nonadherence rates were recorded, health professionals were often unaware of the complex causes, compounded by an inadequacy of adherence assessment tools. Some patients reported nonadherence events because of insufficient education or lack of access to prompt medical guidance. These issues should be addressed to improve clinical practice.

Tyrosine kinase gene rearrangements in epithelial malignancies

Chromosomal rearrangements that lead to oncogenic kinase activation are observed in many epithelial cancers. These cancers express activated fusion kinases that drive the initiation and progression of malignancy, and often have a considerable response to small-molecule kinase inhibitors, which validates these fusion kinases as 'druggable' targets. In this Review, we examine the aetiologic, pathogenic and clinical features that are associated with cancers harbouring oncogenic fusion kinases, including anaplastic lymphoma kinase (ALK), ROS1 and RET. We discuss the clinical outcomes with targeted therapies and explore strategies to discover additional kinases that are activated by chromosomal rearrangements in solid tumours.

Current management of chronic myeloid leukemia with tyrosine kinase inhibitors

The clinical outcomes and survival of tyrosine kinase inhibitor (TKI)-treated patients with chronic myeloid leukemia (CML) have been significantly improved. The aim of this editorial is to outline critical steps of TKI administration practices during the long-term clinical course of CML based on data obtained from randomized clinical trials and international recommendations. The efficacy of TKI treatment, TKI side effects, off-target complications, and long-term morbidities due to both the disease and the drug are common arguments in the management of CML. Complete hematological response, early complete cytogenetic response, faster major molecular response, and deeper, more durable molecular responses (MR4, MR4.5, MR5) are the ultimate goals for TKI-receiving patients with CML.

CONFLICT OF INTEREST

None declared.

Role of exosomes released by chronic myelogenous leukemia cells in angiogenesis

Our study is designed to assess if exosomes released from chronic myelogenous leukemia (CML) cells may modulate angiogenesis. We have isolated and characterized the exosomes generated from LAMA84 CML cells and demonstrated that addition of exosomes to human vascular endothelial cells (HUVEC) induces an increase of both ICAM-1 and VCAM-1 cell adhesion molecules and interleukin-8 expression. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of CML cells to a HUVEC monolayer. We further showed that the treatment with exosomes from CML cells caused an increase in endothelial cell motility accompanied by a loss of VE-cadherin and β-catenin from the endothelial cell surface. Functional characterization of exosomes isolated from CML patients confirmed the data obtained with exosomes derived from CML cell line. CML exosomes caused reorganization into tubes of HUVEC cells cultured on Matrigel. When added to Matrigel plugs in vivo, exosomes induced ingrowth of murine endothelial cells and vascularization of the Matrigel plugs. Our results suggest for the first time that exosomes released from CML cells directly affect endothelial cells modulating the process of neovascularization.

Bosutinib is active in chronic phase chronic myeloid leukemia after imatinib and dasatinib and/or nilotinib therapy failure

Bosutinib, a dual Src/Abl tyrosine kinase inhibitor (TKI), has shown potent activity against chronic myeloid leukemia (CML). This phase 1/2 study evaluated the efficacy and safety of once-daily bosutinib 500 mg in leukemia patients after resistance/intolerance to imatinib. The current analysis included 118 patients with chronic-phase CML who had been pretreated with imatinib followed by dasatinib and/or nilotinib, with a median follow-up of 28.5 months. In this subpopulation, major cytogenetic response was attained by 32% of patients; complete cytogenetic response was attained by 24%, including in one of 3 patients treated with 3 prior TKIs. Complete hematologic response was achieved/maintained in 73% of patients. On-treatment transformation to accelerated/blast phase occurred in 5 patients. At 2 years, Kaplan-Meier-estimated progression-free survival was 73% and estimated overall survival was 83%. Responses were seen across Bcr-Abl mutations, including those associated with dasatinib and nilotinib resistance, except T315I. Bosutinib had an acceptable safety profile; treatment-emergent adverse events were primarily manageable grade 1/2 gastrointestinal events and rash. Grade 3/4 nonhematologic adverse events (> 2% of patients) included diarrhea (8%) and rash (4%). Bosutinib may offer a new treatment option for patients with chronic-phase CML after treatment with multiple TKIs. This trial was registered at www.clinicaltrials.gov as NCT00261846.

Towards clinical applications of selected reaction monitoring for plasma protein biomarker studies

The widespread clinical adoption of protein biomarkers with diagnostic, prognostic and/or predictive value remains a formidable challenge for the biomedical community. From discovery to validation, the path to biomarkers of clinical relevance abounds with many protein candidates, yet so few concrete examples have been substantiated. In this review, we focus on the recent adoption of selected reaction monitoring (SRM) of plasma proteins in the path to clinical use for a broad range of diseases including cancer, cardiovascular disease, genetic disorders and various metabolic disorders. Recent progress reveals a promising outlook for clinical applications using SRM, which now provides the routine analysis of clinically relevant protein markers at low nanogram per millilitre in plasma.

Unbiased functional proteomics strategy for protein kinase inhibitor validation and identification of bona fide protein kinase substrates: application to identification of EEF1D as a substrate for CK2

Protein kinases have emerged as attractive targets for treatment of several diseases prompting large-scale phosphoproteomics studies to elucidate their cellular actions and the design of novel inhibitory compounds. Current limitations include extensive reliance on consensus predictions to derive kinase-substrate relationships from phosphoproteomics data and incomplete experimental validation of inhibitors. To overcome these limitations in the case of protein kinase CK2, we employed functional proteomics and chemical genetics to enable identification of physiological CK2 substrates and validation of CK2 inhibitors including TBB and derivatives. By 2D electrophoresis and mass spectrometry, we identified the translational elongation factor EEF1D as a protein exhibiting CK2 inhibitor-dependent decreases in phosphorylation in (32)P-labeled HeLa cells. Direct phosphorylation of EEF1D by CK2 was shown by performing CK2 assays with EEF1D -FLAG from HeLa cells. Dramatic increases in EEF1D phosphorylation following λ-phosphatase treatment and phospho- EEF1D antibody recognizing EEF1D pS162 indicated phosphorylation at the CK2 site in cells. Furthermore, phosphorylation of EEF1D in the presence of TBB or TBBz is restored using CK2 inhibitor-resistant mutants. Collectively, our results demonstrate that EEF1D is a bona fide physiological CK2 substrate for CK2 phosphorylation. Furthermore, this validation strategy could be adaptable to other protein kinases and readily combined with other phosphoproteomic methods.

Expression of EBV encoded viral RNA 1, 2 and anti-inflammatory cytokine (interleukin-10) in FFPE lymphoma specimens: a preliminary study for diagnostic implication in Pakistan

BACKGROUND

Epstein Barr Virus (EBV) plays a significant role as a cofactor in the process of tumorigenesis and has consistently been associated with a variety of malignancies. EBV encoded RNAs (EBER1 and EBER2) are the most abundant viral transcripts in latently EBV-infected cells and their role in viral infection is still unclear. Formalin fixed paraffin embedded (FFPE) tissues of surgically removed carcinoma biopsies are widely available form but have never been exploited for expressional studies previously in Pakistan. Immunohistochemistry (IHC) and in situ hybridization (ISH) in FFPE biopsy tissues remains the gold standard for proving EBV relationship in a histopathological lesion but their reagents associated limitations confines their reliability in some applications. Recently introduced targeted drug delivery systems induce viral lytic gene expression and therefore require more sensitive method to quantify viral as well as cellular gene expression.

METHODS

Eight (8) lymphoma samples were screened to detect the EBV genome. Qualitative and quantitative expression of EBV Encoded RNAs (EBER1, EBER2) and anti-inflammatory cytokine (interleukin-10) in FFPE EBV positive lymphoma tissue samples were then analysed by using reverse transcriptase polymerase chain reaction (RT-PCR) and real time polymerase chain reaction (qRT-PCR), respectively.

RESULTS

In this study we have successfully quantified elevated expressional levels of both cellular and viral transcripts, namely EBER1, EBER2 and anti-inflammatory cytokine (IL-10) in the FFPE Burkitt's lymphoma (BL) specimens of Pakistani origin.

CONCLUSIONS

These results indicate that FFPE samples may retain viral as well as cellular RNA expression information at detectable level. To our knowledge, this is first study which represents elevated expressional levels of EBER1, EBER2 and IL-10 in FFPE tissue samples of Burkitt's lymphoma in Pakistan. These observations will potentially improve current lacunas in clinical as well as diagnostic practices in Pakistan and can be further exploited to develop new strategies for studying cellular and/or viral gene expression.

Monitoring response and resistance to treatment in chronic myeloid leukemia

Chronic myeloid leukemia (cml) results from expression of the constitutive tyrosine kinase activity of the Bcr-Abl oncoprotein. Imatinib, a tyrosine kinase inhibitor (tki), is highly effective in the treatment of cml. However, some patients treated with imatinib will fail to respond, will respond suboptimally, or will relapse because of primary or acquired resistance or intolerance. Research activities focusing on the mechanisms that underlie imatinib resistance have identified mutations in the BCR-ABL gene, clonal evolution, and amplification of the BCR-ABL gene as common causes. Cytogenetic and molecular techniques are currently used to monitor cml therapy for both response and relapse. With multiple and more potent therapeutic options now available, monitoring techniques can permit treatment to be tailored to the individual patient based on disease characteristics-for example, according to BCR-ABL mutation profile or to patient characteristics such as certain comorbid conditions. This approach should benefit patients by increasing the potential for better long-term outcomes.

Acetylome and phosphoproteome modifications in imatinib resistant chronic myeloid leukaemia cells treated with valproic acid

Chronic myeloid leukaemia has a specific therapy: BCR/ABL inhibitor imatinib. Resistance due to BCR/ABL dependent and independent mechanisms is partially reversible by histone deacetylase inhibitors. We analysed by 2D-electrophoresis and anti-pan-acetylated and anti-phosphotyrosine immunoblots, followed by spot-matching and MALDI-TOF mass spectrometry, which proteome modifications would parallel restoration of sensitivity to imatinib by valproic acid (VPA). VPA plus imatinib significantly increased acetylation of HSP90 and hnRNP L and decreased phosphorylation of HSPs and hnRNPs in imatinib resistant cells. VPA was able to modify profoundly acetylome and phosphoproteome of CML cells, while reverting resistance to imatinib.

CCC meets ICU: redefining the role of critical care of cancer patients

BACKGROUND

Currently the majority of cancer patients are considered ineligible for intensive care treatment and oncologists are struggling to get their patients admitted to intensive care units. Critical care and oncology are frequently two separate worlds that communicate rarely and thus do not share novel developments in their fields. However, cancer medicine is rapidly improving and cancer is eventually becoming a chronic disease. Oncology is therefore characterized by a growing number of older and medically unfit patients that receive numerous novel drug classes with unexpected side effects.

DISCUSSION

All of these changes will generate more medically challenging patients in acute distress that need to be considered for intensive care. An intense exchange between intensivists, oncologists, psychologists and palliative care specialists is warranted to communicate the developments in each field in order to improve triage and patient treatment. Here, we argue that "critical care of cancer patients" needs to be recognized as a medical subspecialty and that there is an urgent need to develop it systematically.

CONCLUSION

As prognosis of cancer improves, novel therapeutic concepts are being introduced and more and more older cancer patients receive full treatment the number of acutely ill patients is growing significantly. This development a major challenge to current concepts of intensive care and it needs to be redefined who of these patients should be treated, for how long and how intensively.

Small interfering RNA against BCR-ABL transcripts sensitize mutated T315I cells to nilotinib

BACKGROUND

Selective inhibition of the BCR-ABL tyrosine kinase by RNA interference has been demonstrated in leukemic cells. We, therefore, evaluated specific BCR-ABL small interfering RNA silencing in BCR-ABL-positive cell lines, including those resistant to imatinib and particularly those with the T315I mutation.

DESIGN AND METHODS

The factor-independent 32Dp210 BCR-ABL oligoclonal cell lines and human imatinib-resistant BCR-ABL-positive cells from patients with leukemic disorders were investigated. The effects of BCR-ABL small interfering RNA or the combination of BCR-ABL small interfering RNA with imatinib and nilotinib were compared with those of the ABL inhibitors imatinib and nilotinib.

RESULTS

Co-administration of BCR-ABL small interfering RNA with imatinib or nilotinib dramatically reduced BCR-ABL expression in wild-type and mutated BCR-ABL cells and increased the lethal capacity. BCR-ABL small interfering RNA significantly induced apoptosis and inhibited proliferation in wild-type (P<0.0001) and mutated cells (H396P, T315I, P<0.0001) versus controls. Co-treatment with BCR-ABL small interfering RNA and imatinib or nilotinib resulted in increased inhibition of proliferation and induction of apoptosis in T315I cells as compared to imatinib or nilotinib alone (P<0.0001). Furthermore, the combination of BCR-ABL small interfering RNA with imatinib or nilotinib significantly (P<0.01) reversed multidrug resistance-1 gene-dependent resistance of mutated cells. In T315I cells BCR-ABL small interfering RNA with nilotinib had powerful effects on cell cycle distribution.

CONCLUSIONS

Our data suggest that silencing by BCR-ABL small interfering RNA combined with imatinib or nilotinib may be associated with an additive antileukemic activity against tyrosine kinase inhibitor-sensitive and resistant BCR-ABL cells, and might be an alternative approach to overcome BCR-ABL mutations.

Toward theragnostics

Theragnostics is a treatment strategy that combines therapeutics with diagnostics. It associates both a diagnostic test that identifies patients most likely to be helped or harmed by a new medication, and targeted drug therapy based on the test results. Bioinformatics, genomics, proteomics, and functional genomics are molecular biology tools essential for the progress of molecular theragnostics. These tools generate the genetic and protein information required for the development of diagnostic assays. Theragnostics includes a wide range of subjects, including personalized medicine, pharmacogenomics, and molecular imaging to develop efficient new targeted therapies with adequate benefit/risk to patients and a better molecular understanding of how to optimize drug selection. Furthermore, theragnostics aims to monitor the response to the treatment, to increase drug efficacy and safety. In addition, theragnostics could eliminate the unnecessary treatment of patients for whom therapy is not appropriate, resulting in significant drug cost savings for the healthcare system. However, the introduction of theragnostic tests into routine health care requires both a demonstration of cost-effectiveness and the availability of appropriate accessible testing systems. This review reports validation studies in oncology and infectious diseases that have demonstrated the benefits of such approach in well-defined subpopulations of patients, moving the field from the drug development process toward clinical practice and routine application. Theragnostics may change the usual business model of pharmaceutical companies from the classic blockbuster model toward targeted therapies.

Kinase domain point mutations in Philadelphia chromosome-positive acute lymphoblastic leukemia emerge after therapy with BCR-ABL kinase inhibitors

BACKGROUND

BCR-ABL kinase domain (KD) mutations are detected in approximately 45% of patients with imatinib-resistant chronic myeloid leukemia. Patterns of KD mutations in Philadelphia chromosome (Ph)-positive acute lympho- blastic leukemia (ALL) are less well studied.

METHODS

The authors assessed KD mutations in patients with recurrent Ph-positive ALL after treatments that included 1 or more kinase inhibitors (n = 24 patients) or no prior kinase inhibitor (KI) therapy (n = 12 patients).

RESULTS

ABL KD mutations were detected by direct sequencing in 15 of 17 patients (88%) who had recurrent Ph-positive ALL and received prior imatinib (n = 16) or dasatinib (n = 1) treatment and in 6 of 7 patients (86%) who had resistant/recurrent tumors treated with >or=2 KIs compared with 0 of 12 patients with recurrent Ph-positive ALL who never received KIs. A restricted set of mutations was observed, mostly Y253H and T315I, and were detected on average 10 months after KI initiation, and mutations were not detected in the initial tumor samples before KI therapy in 12 patients who were assessed. Using a more sensitive pyrosequencing method, mutations were not detected at codons 315 and 253 in the diagnostic samples from those 12 patients or in 30 patients with Ph-positive ALL who never developed recurrent disease.

CONCLUSIONS

ABL KD mutations, especially at codons 315 and 253, emerged at the time of disease recurrence in the vast majority of patients who had Ph-positive ALL and received maintenance KI therapy. Thus, the authors concluded that ongoing KI exposure may alter the patterns of recurrence and favor the outgrowth of clones with KI-resistant mutations.

EVI1 activation in blast crisis CML due to juxtaposition to the rare 17q22 partner region as part of a 4-way variant translocation t(9;22)

Background

Variant translocations t(9;22) occur in 5 to 10% of newly diagnosed CMLs and additional genetic changes are present in 60–80% of patients in blast crisis (BC). Here, we report on a CML patient in blast crisis presenting with a four-way variant t(9;22) rearrangement involving the EVI1 locus.

Methods

Dual-colour Fluorescence In Situ Hybridisation was performed to unravel the different cytogenetic aberrations. Expression levels of EVI1 and BCR/ABL1 were investigated using real-time quantitative RT-PCR.

Results

In this paper we identified a patient with a complex 4-way t(3;9;17;22) which, in addition to BCR/ABL1 gene fusion, also resulted in EVI1 rearrangement and overexpression.

Conclusion

This report illustrates how a variant t(9;22) translocation can specifically target a second oncogene most likely contributing to the more aggressive phenotype of the disease. Molecular analysis of such variants is thus warranted to understand the phenotypic consequences and to open the way for combined molecular therapies in order to tackle the secondary oncogenic effect which is unresponsive to imatinib treatment.