Imatinib: a review of its use in chronic myeloid leukaemia

Future Directions in Therapies for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is caused by a complex interplay among hyperinflammation, endothelial dysfunction, and alveolar epithelial injury. Targeted treatments toward the underlying pathways have been unsuccessful in unselected patient populations. The first reliable biological subphenotypes reflective of these biological disease states have been identified in the past decade. Subphenotype targeted intervention studies are needed to advance the pharmacologic treatment of ARDS.

Chlorine containing tetrahydropyrimidines: Synthesis, characterization, anticancer activity and mechanism of action

The aim of the presented research was to explore anticancer potential of eleven newly synthesized tetrahydropyrimidine derivatives. The compounds were synthesized via Biginelli multicomponent one-pot reaction using different derivatives of vanillin, ethyl 4-chloroacetoacetate and (N-methyl)urea. The cytotoxic effects of the compounds were examined on three human malignant cell lines (HeLa, K562, and MCF7), and normal lung fibroblasts MRC-5. The mechanisms of anticancer activity were examined for two compounds 4a and 4b which showed the strongest and selective cytotoxicity against chronic myelogenous leukaemia K562 cells (IC50 = 1.76 ± 0.09, and 1.66 ± 0.05, respectively). The changes of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and vascular endothelial growth factor A (VEGFA) were investigated in the K562 cell line, as well as oncomiRNA miR-10b, miR-23a described to have both features, depending on a specific type of malignancy, and miR-34a with mostly described as a tumour suppressor.

The current landscape of antifibrotic therapy across different organs: A systematic approach

Fibrosis is a common pathological process that can affect virtually all the organs, but there are hardly any effective therapeutic options. This has led to an intense search for antifibrotic therapies over the last decades, with a great number of clinical assays currently underway. We have systematically reviewed all current and recently finished clinical trials involved in the development of new antifibrotic drugs, and the preclinical studies analyzing the relevance of each of these pharmacological strategies in fibrotic processes affecting tissues beyond those being clinically studied. We analyze and discuss this information with the aim of determining the most promising options and the feasibility of extending their therapeutic value as antifibrotic agents to other fibrotic conditions.

Chronic myeloid leukemia with two rare fusion gene transcripts of atypical BCR::ABL: A case report and literature review

RATIONALE

Imatinib is a standard treatment for Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML), but its efficacy in rare BCR::ABL variants is underexplored.

PATIENT CONCERNS

A 67-year-old woman was admitted to the Second Affiliated Hospital of Xi'an Jiaotong University in March 2022 due to elevated white blood cells.

DIAGNOSIS

Karyotype analysis revealed clonal abnormalities involving the variant t(9;22) and positive results for atypical BCR::ABL variants (e14a3 and e13a3). The clinical diagnosis was CML, chronic phase, Ph+, with rare BCR::ABL-e13a3- and BCR::ABL-e14a3-positive findings.

INTERVENTION

The patient was administered daily imatinib mesylate (400 mg).

OUTCOMES

After 4 weeks, a swift molecular response was observed: BCR::ABL-e13a3 transcript level at 2.82 × 10-1 (28.24%), and BCR::ABL-e14a3 transcript level at 4.68 × 10-1 (46.76%). Within 3 months, a complete cytogenetic response was achieved, with a Ph chromosome ratio of 0. Early molecular response was evident as BCR::ABL-e13a3 transcript level reached 5.11 × 10-3 (0.51%), and BCR::ABL-e14a3 transcript level at 6.26 × 10-3 (0.63%). The imatinib mesylate treatment continued without significant toxicity.

LESSONS

This case emphasizes the potential effectiveness of imatinib mesylate in managing rare BCR::ABL fusion gene variants of CML. Screening for these atypical variants is advised for suspected CML patients who test negative for common BCR::ABL fusion gene variants. The presented case underscores the positive outcomes achieved with imatinib treatment for a patient with rare BCR::ABL variants, contributing valuable insights for the management of similar cases. Screening for unusual fusion gene variants should be a consideration in CML diagnosis for comprehensive treatment strategies.

Case Report of Renal Calculi in a Child Receiving Imatinib for Acute Lymphoblastic Leukemia

Rationale

Imatinib is used in the treatment of Philadelphia chromosome positive (Ph+) leukemias and has been reported to have a direct effect on bone physiology.

Presentation

To report on a child with Ph+ acute lymphoblastic leukemia who presented with bilateral flank pain and gross hematuria.

Diagnosis

She was diagnosed with obstructive kidney stones 101 days after commencing daily oral imatinib. Stone analysis revealed the presence of calcium phosphate.

Interventions and outcome

The patient passed the stones spontaneously with medical therapy that included the use of thiazide, allopurinol, and potassium citrate, but she required temporary insertion of a double-J stent to relieve an obstruction.

Novel findings

Imatinib inhibits receptor tyrosine kinases and stimulates the flux of calcium from the extracellular fluid into bone, resulting in hypocalcemia with a compensatory rise in parathyroid hormone that may result in phosphaturia and the formation of calcium phosphate stones. Given that kidney stones are rare events in children, we believe that monitoring for kidney stone formation needs to be performed in children receiving imatinib.

Analysis of intracellular tyrosine phosphorylation in circulating neutrophils as a rapid assay for the in vivo effect of oral tyrosine kinase inhibitors

Tyrosine kinases are crucial signaling components of diverse biological processes and are major therapeutic targets in various malignancies and immune-mediated disorders. A critical step of development of novel tyrosine kinase inhibitors is the transition from the confirmation of the in vitro effects of drug candidates to the analysis of their in vivo efficacy. To facilitate this transition, we have developed a rapid in vivo assay for the analysis of the effect of oral tyrosine kinase inhibitors on basal tyrosine phosphorylation of circulating mouse neutrophils. The assay uses a single drop of peripheral blood without sacrificing the mice. Flow cytometry using intracellular staining by fluorescently labeled anti-phosphotyrosine antibodies revealed robust basal tyrosine phosphorylation in resting circulating neutrophils. This signal was abrogated by the use of isotype control antibodies or by pre-saturation of the anti-phosphotyrosine antibodies with soluble phosphotyrosine amino acids or tyrosine-phosphorylated peptides. Basal tyrosine phosphorylation was dramatically reduced in neutrophils of triple knockout mice lacking the Src-family tyrosine kinases Hck, Fgr, and Lyn. Neutrophil tyrosine phosphorylation was also abrogated by oral administration of the Abl/Src-family inhibitor dasatinib, a clinically used anti-leukemic agent. Detailed dose-response and kinetic studies revealed half-maximal reduction of neutrophil tyrosine phosphorylation by 2.9 mg/kg dasatinib, with maximal reduction observed 2 h after inhibitor administration. Taken together, our assay allows highly efficient analysis of the in vivo effect of orally administered tyrosine kinase inhibitors, and may be used as a suitable alternative to other existing approaches.

Novel Phthalic-Based Anticancer Tyrosine Kinase Inhibitors: Design, Synthesis and Biological Activity

In this work, fragments of isophthalic and terephthalic acids are proposed as a structural scaffold to develop potential inhibitors of protein kinases. Novel isophthalic and terephthalic acid derivatives were designed as type-2 protein kinase inhibitors, synthesized and subjected to physicochemical characterization. The screening of their cytotoxic actions against a panel of cell lines derived from different types of tumors (liver, renal, breast and lung carcinomas, as well as chronic myelogenous and promyelocytic leukemia) and normal human B lymphocyte, for the sake of comparison, was performed. Compound 5 showed the highest inhibitory activity against four cancer cell lines, K562, HL-60, MCF-7 and HepG2 (IC50 = 3.42, 7.04, 4.91 and 8.84 µM, respectively). Isophthalic derivative 9 revealed a high potency against EGFR and HER2, at the levels of 90% and 64%, respectively, being comparable to lapatinib at 10 µM. In general, tumor cell cultures were more sensitive to isophthalic acid derivatives than to terephthalic acid ones. In cell cycle studies, isophthalic analogue 5 showed a pronounced dose-dependent effect, and with the increase in its concentration up to 10.0 µM, the number of living cells decreased to 38.66%, while necrosis reached 16.38%. The considered isophthalic compounds had a similar docking performance to that of sorafenib against the VEGFR-2 (PDB id: 4asd, 3wze). The correct binding of compounds 11 and 14 with VEGFR-2 was validated using MD simulations and MM-GPSA calculations.

Pharmacokinetics and safety of dasatinib and its generic: a phase I bioequivalence study in healthy Chinese subjects

BACKGROUND

Dasatinib (Sprycel®) is a tyrosine kinase inhibitor for treating chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia.

RESEARCH DESIGN & METHODS

We designed a clinical study to demonstrate that the dasatinib tablet (YiNiShu®) (Chia Tai Tianqing Pharmaceutical Group Co., Ltd) and Dasatinib (Bristol Myers Squibb) were bioequivalent under fasting and fed conditions. The whole study was structured into the fasting trial and the postprandial trial. Each period, subjects were given 50 mg dasatinib or its generic. The RSABE (reference scale average bioequivalence) and ABE (average bioequivalence) methods were employed to assess bioequivalence by pharmacokinetics (PK) parameters for a highly variable drug.

RESULTS

32 and 24 eligible volunteers were enrolled in the fasting and postprandial trials, respectively. In the fasting trial, the RSABE method was performed, and point estimates of C_max, AUC_0-t, and AUC_0-∞ met the bioequivalence criteria. In the postprandial trial, the ABE method was performed, and the 90% CI of the geometric mean ratio (GMR) for PK parameters met the requirements of bioequivalence standards.

CONCLUSION

The results proved that the PK parameters of the two drugs were similar and bioequivalent, indicating that both drugs had a good safety profile.

CLINICAL TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov (Number: NCT05640804) and Drug Clinical Trial Registration and Information Disclosure Platform (Number: CTR20181708).

Targeting human thymidylate synthase: Ensemble-based virtual screening for drug repositioning and the role of water

A drug repositioning computational approach was carried to search inhibitors for human thymidylate synthase. An ensemble-based virtual screening of FDA-approved drugs showed the drugs Imatinib, Lumacaftor and Naldemedine to be likely candidates for repurposing. The role of water in the drug-receptor interactions was revealed by the application of an extended AutoDock scoring function that included the water forcefield. The binding affinity scores when hydrated ligands were docked were improved in the drugs considered. Further binding free energy calculations based on the Molecular Mechanics Poisson-Boltzmann Surface Area method revealed that Imatinib, Lumacaftor and Naldemedine scored -130.7 ± 28.1, -210.6 ± 29.9 and -238.0 ± 25.4 kJ/mol, respectively, showing good binding affinity for the candidates considered. Overall, the analysis of the molecular dynamics trajectory of the receptor-drug complexes revealed stable structures for Imatinib, Lumacaftor and Naldemedine, for the entire simulation time.

Hypoxic stress and hypoxia-inducible factors in leukemias

To cope with hypoxic stress, ancient organisms have developed evolutionally conserved programs centered on hypoxia-inducible transcriptional factors (HIFs). HIFs and their regulatory proteins have evolved as rheostats to adapt cellular metabolism to atmospheric oxygen fluctuations, but the amplitude of their transcriptional programs has tremendously increased along evolution to include a wide spectrum of physiological and pathological processes. The bone marrow represents a notable example of an organ that is physiologically exposed to low oxygen levels and where basal activation of hypoxia signaling appears to be intrinsically wired within normal and neoplastic hematopoietic cells. HIF-mediated responses are mainly piloted by the oxygen-labile α subunits HIF1α and HIF2α, and current literature suggests that these genes have a functional specification that remains to be fully defined. Since their identification in the mid 90s, HIF factors have been extensively studied in solid tumors, while their implication in leukemia has lagged behind. In the last decades however, many laboratories have addressed the function of hypoxia signaling in leukemia and obtained somewhat contradictory results. Suppression of HIFs expression in different types of leukemia has unveiled common leukemia-promoting functions such as stimulation of bone marrow neoangiogenesis, maintenance of leukemia stem cells and chemoresistance. However, genetic studies are revealing that a definition of HIF factors as bona fide tumor promoters is overly simplistic, and, depending on the leukemia subtype, the specific oncogenic event, or the stage of leukemia development, activation of hypoxia-inducible genes may lead to opposite consequences. With this article we will provide an updated summary of the studies describing the regulation and function of HIF1α and HIF2α in blood malignancies, spanning from acute to chronic, lymphoid to myeloid leukemias. In discussing these data, we will attempt to provide plausible explanations to contradictory findings and point at what we believe are areas of weakness in which further investigations are urgently needed. Gaining additional knowledge into the role of hypoxia signaling in leukemia appears especially timely nowadays, as new inhibitors of HIF factors are entering the clinical arena for specific types of solid tumors but their utility for patients with leukemia is yet to be determined.

A case report of nilotinib-induced irreversible interstitial lung disease

RATIONALE

Nilotinib is a second line tyrosine kinase inhibitor to treat patients with chronic myeloid leukemia after imatinib resistance or intolerance. Drug related pulmonary complication is known to be rare. We discuss a case of nilotinib-induced interstitial lung disease presenting with nonspecific interstitial pneumonia on the unilateral lung.

PATIENT CONCERNS

A 46-year-old man with chronic-phase chronic myeloid leukemia presented with cough and weight loss for 2 months. He had been treated with nilotinib for 52 months.

DIAGNOSIS

Computed tomography scan showed right lung dominant consolidations, ground glass opacities and traction bronchiectasis. Bronchoalveolar lavage fluid analysis revealed no evidence of infection or malignancy. Surgical lung biopsy specimen was consistent with fibrosing nonspecific interstitial pneumonia. The patient was diagnosed with nilotinib induced interstitial lung disease.

INTERVENTIONS

Corticosteroid treatment was initiated with prednisolone (50 mg daily) and slowly tapered down for 2 months.

OUTCOMES

Cough improved after the course of corticosteroid treatment. However, fibrotic lung lesions persisted. Reinitiation of nilotinib resulted in the worsening of lung lesions.

LESSONS

We report a case of irreversible interstitial lung disease that caused by nilotinib. Clinicians should have suspicion of this potential pulmonary complication in patients with respiratory symptoms and abnormal radiologic findings during nilotinib treatment, albeit rarely.

Metal-Organic Framework-Based Composites for the Detection and Monitoring of Pharmaceutical Compounds in Biological and Environmental Matrices

The production of synthetic drugs is considered a huge milestone in the healthcare sector, transforming the overall health, aging, and lifestyle of the general population. Due to the surge in production and consumption, pharmaceutical drugs have emerged as potential environmental pollutants that are toxic with low biodegradability. Traditional chromatographic techniques in practice are time-consuming and expensive, despite good precision. Alternatively, electroanalytical techniques are recently identified to be selective, rapid, sensitive, and easier for drug detection. Metal-organic frameworks (MOFs) are known for their intrinsic porous nature, high surface area, and diversity in structural design that provides credible drug-sensing capacities. Long-term reusability and maintaining chemo-structural integrity are major challenges that are countered by ligand-metal combinations, optimization of synthetic conditions, functionalization, and direct MOFs growth over the electrode surface. Moreover, chemical instability and lower conductivities limited the mass commercialization of MOF-based materials in the fields of biosensing, imaging, drug release, therapeutics, and clinical diagnostics. This review is dedicated to analyzing the various combinations of MOFs used for electrochemical detection of pharmaceutical drugs, comprising antibiotics, analgesics, anticancer, antituberculosis, and veterinary drugs. Furthermore, the relationship between the composition, morphology and structural properties of MOFs with their detection capabilities for each drug species is elucidated.

Tyrosine kinase inhibitors as next generation oncological therapeutics: Current strategies, limitations and future perspectives

Protein kinases, a class of enzymes that govern various biological phenomena at a cellular level, are responsible for signal transduction in cells that regulate cellular proliferation, differentiation, and growth. Protein kinase enzyme mutation results in abnormal cell division leading to a pathological condition like cancer. Tyrosine kinase (TK) inhibitors, which helps as a potential drug candidate for the treatment of cancer, are continuously being developed. Majority of these drug candidates are being administered as conventional oral dosage form, which provides limited safety and efficacy due to non-specific delivery and uncontrolled biodistribution resulting into the adverse effects. A controlled drug delivery approach for the delivery of TK inhibitors may be a potential strategy with significant safety and efficacy profile. Novel drug delivery strategies provide target-specific drug delivery, improved pharmacokinetic behaviour, and sustained release leading to lower doses and dosing frequency with significantly reduced side effects. Along with basic aspects of tyrosine kinase, this review discusses various aspects related to the application of tyrosine kinase inhibitors in clinical oncological setting. Furthermore, the limitations/challenges and formulation advancements related to this class of candidates particularly for cancer management have been reviewed. It is expected that innovations in drug delivery approaches for TK inhibitors using novel techniques will surely provide a new insights for improved cancer treatment and patients' life quality.

Antiprotozoal agents: How have they changed over a decade?

Neglected tropical diseases are a diverse group of communicable diseases that are endemic in low- or low-to-middle-income countries located in tropical and subtropical zones. The number and availability of drugs for treating these diseases are low, the administration route is inconvenient in some cases, and most of them have safety, efficacy, or adverse/toxic reaction issues. The need for developing new drugs to deal with these issues is clear, but one of the most drastic consequences of this negligence is the lack of interest in the research and development of new therapeutic options among major pharmaceutical companies. Positive changes have been achieved over the last few years, although the overall situation remains alarming. After more than one decade since the original work reviewing antiprotozoal agents came to light, now it is time to question ourselves: How has the scenario for the treatment of protozoal diseases such as malaria, leishmaniasis, human African trypanosomiasis, and American trypanosomiasis changed? This review covers the last decade in terms of the drugs currently available for the treatment of these diseases as well as the clinical candidates being currently investigated.

Synthesis and Cytotoxic Activity of Combretastatin A-4 and 2,3-Diphenyl-2H-indazole Hybrids

Cancer is the second leading cause of death, after cardiovascular diseases. Different strategies have been developed to treat cancer; however, chemotherapy with cytotoxic agents is still the most widely used treatment approach. Nevertheless, drug resistance to available chemotherapeutic agents is still a serious problem, and the development of new active compounds remains a constant need. Taking advantage of the molecular hybridization approach, in the present work we designed, synthesized, and tested the cytotoxic activity of two hybrid compounds and seven derivatives based on the structure of combretastatin A-4 and 2,3-diphenyl-2H-indazole. Practical modifications of reported synthetic protocols for 2-pheny-2H-indazole and 2,3-dipheny-2H-indazole derivatives under microwave irradiation were implemented. The cytotoxicity assays showed that our designed hybrid compounds possess strong activity, especially compound 5, which resulted even better than the reference drug cisplatin against HeLa and SK-LU-1 cells (IC₅₀ of 0.16 and 6.63 µM, respectively), and it had similar potency to the reference drug imatinib against K562 cells. Additionally, in silico and in vitro studies strongly suggest tubulin as the molecular target for hybrid compound 5.

Kinase drug discovery 20 years after imatinib: progress and future directions

Protein kinases regulate nearly all aspects of cell life, and alterations in their expression, or mutations in their genes, cause cancer and other diseases. Here, we review the remarkable progress made over the past 20 years in improving the potency and specificity of small-molecule inhibitors of protein and lipid kinases, resulting in the approval of more than 70 new drugs since imatinib was approved in 2001. These compounds have had a significant impact on the way in which we now treat cancers and non-cancerous conditions. We discuss how the challenge of drug resistance to kinase inhibitors is being met and the future of kinase drug discovery.

Regulation of T cell differentiation by the AP-1 transcription factor JunB

JunB, a component of the activator protein-1 (AP-1) transcription factor, is known to exhibit an important role in bone formation and bone marrow cell proliferation. During T helper type 2 (Th2) cell differentiation, JunB contributes to the regulation of interleukin (IL)-4 expression, and AP-1 and nuclear factor of activated T cell (NFAT) constitute a heteromer and contribute to IL-2 production. However, the role of JunB in other T cells has not been investigated. In 2017, it was revealed that JunB, in collaboration with basic leucine zipper ATF-like transcription factor (BATF), regulates the expression of Th17-related genes. Furthermore, JunB was found to play an important role in regulatory T (Treg) cell differentiation, contributing to CD25 expression and IL-2 production. IL-2 is a T cell activator and has been shown as a necessary factor for Treg proliferation. Here, we review the role of JunB in T cells based on basic research data and discuss the potential for its clinical applications.

Drug repurposing for the treatment of COVID-19: Pharmacological aspects and synthetic approaches

In December 2019, a new variant of SARS-CoV emerged, the so-called acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus causes the new coronavirus disease (COVID-19) and has been plaguing the world owing to its unprecedented spread efficiency, which has resulted in a huge death toll. In this sense, the repositioning of approved drugs is the fastest way to an effective response to a pandemic outbreak of this scale. Considering these facts, in this review we provide a comprehensive and critical discussion on the chemical aspects surrounding the drugs currently being studied as candidates for COVID-19 therapy. We intend to provide the general chemical community with an overview on the synthetic/biosynthetic pathways related to such molecules, as well as their mechanisms of action against the evaluated viruses and some insights on the pharmacological interactions involved in each case. Overall, the review aims to present the chemical aspects of the main bioactive molecules being considered to be repositioned for effective treatment of COVID-19 in all phases, from the mildest to the most severe.

An SPR investigation into the therapeutic drug monitoring of the anticancer drug imatinib with selective aptamers operating in human plasma

An ss-DNA aptamer-based biosensor was devised to detect the anticancer drug imatinib by means of surface plasmon resonance.

Blocking PDGF-CC signaling ameliorates multiple sclerosis-like neuroinflammation by inhibiting disruption of the blood-brain barrier

Disruption of blood–brain barrier (BBB) integrity is a feature of various neurological disorders. Here we found that the BBB is differently affected during the preclinical, progression and remission phase of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). We have identified an upregulation of pro-inflammatory and pro-angiogenic factors in the BBB transcriptome and down-regulation of endothelial tight junction members coinciding with elevated BBB leakage specifically during the progression phase. These changes were antagonized by blocking PDGFRα signaling with the small tyrosine kinase inhibitor imatinib. Moreover, targeting the PDGFRα ligand PDGF-CC using a neutralizing antibody, facilitated recovery of BBB integrity and improvement of EAE symptoms. Intracerebroventricular injection of PDGF-CC induced upregulation, whereas blocking PDGF-CC during EAE led to downregulation of Tnfa and Il1a at the BBB. Our findings suggest that blocking PDGF-CC counteracts fundamental aspects of endothelial cell activation and disruption of the BBB by decreasing Tnfa and Il1a expression. We also demonstrate that both PDGF-CC and its receptor PDGFRα were upregulated in MS lesions indicating that blocking PDGF-CC may be considered a novel treatment for MS.

Potential Therapeutic Options for COVID-19: Current Status, Challenges, and Future Perspectives

The COVID-19 pandemic represents an unprecedented challenge for the researchers to offer safe, tolerable, and effective treatment strategies for its causative agent known as SARS-CoV-2. With the rapid evolution of the pandemic, even the off-label use of existing drugs has been restricted by limited availability. Several old antivirals, antimalarial, and biological drugs are being reconsidered as possible therapies. The effectiveness of the controversial treatment options for COVID-19 such as nonsteroidal antiinflammatory drugs, angiotensin 2 conversion enzyme inhibitors and selective angiotensin receptor blockers was also discussed. A systemic search in the PubMed, Science Direct, LitCovid, Chinese Clinical Trial Registry, and ClinicalTrials.gov data bases was conducted using the keywords "coronavirus drug therapy," passive immunotherapy for COVID-19', "convalescent plasma therapy," (CPT) "drugs for COVID-19 treatment," "SARS-CoV-2," "COVID-19," "2019-nCoV," "coronavirus immunology," "microbiology," "virology," and individual drug names. Systematic reviews, case presentations and very recent clinical guidelines were included. This narrative review summarizes the available information on possible therapies for COVID-19, providing recent data to health professionals.

Can Bottom-Up Synthetic Biology Generate Advanced Drug-Delivery Systems?

Creating a magic bullet that can selectively kill cancer cells while sparing nearby healthy cells remains one of the most ambitious objectives in pharmacology. Nanomedicine, which relies on the use of nanotechnologies to fight disease, was envisaged to fulfill this coveted goal. Despite substantial progress, the structural complexity of therapeutic vehicles impedes their broad clinical application. Novel modular manufacturing approaches for engineering programmable drug carriers may be able to overcome some fundamental limitations of nanomedicine. We discuss how bottom-up synthetic biology principles, empowered by microfluidics, can palliate current drug carrier assembly limitations, and we demonstrate how such a magic bullet could be engineered from the bottom up to ultimately improve clinical outcomes for patients.

Amide Bond Bioisosteres: Strategies, Synthesis, and Successes

The amide functional group plays a key role in the composition of biomolecules, including many clinically approved drugs. Bioisosterism is widely employed in the rational modification of lead compounds, being used to increase potency, enhance selectivity, improve pharmacokinetic properties, eliminate toxicity, and acquire novel chemical space to secure intellectual property. The introduction of a bioisostere leads to structural changes in molecular size, shape, electronic distribution, polarity, pK_a, dipole or polarizability, which can be either favorable or detrimental to biological activity. This approach has opened up new avenues in drug design and development resulting in more efficient drug candidates introduced onto the market as well as in the clinical pipeline. Herein, we review the strategic decisions in selecting an amide bioisostere (the why), synthetic routes to each (the how), and success stories of each bioisostere (the implementation) to provide a comprehensive overview of this important toolbox for medicinal chemists.

Imidazo[1,2-b]pyrazole-7-Carboxamide Derivative Induces Differentiation-Coupled Apoptosis of Immature Myeloid Cells Such as Acute Myeloid Leukemia and Myeloid-Derived Suppressor Cells

Chemotherapy-induced differentiation of immature myeloid progenitors, such as acute myeloid leukemia (AML) cells or myeloid-derived suppressor cells (MDSCs), has remained a challenge for the clinicians. Testing our imidazo[1,2-b]pyrazole-7-carboxamide derivative on HL-60 cells, we obtained ERK phosphorylation as an early survival response to treatment followed by the increase of the percentage of the Bcl-xl^bright and pAkt^bright cells. Following the induction of Vav1 and the AP-1 complex, a driver of cellular differentiation, FOS, JUN, JUNB, and JUND were elevated on a concentration and time-dependent manner. As a proof of granulocytic differentiation, the cells remained non-adherent, the expression of CD33 decreased; the granularity, CD11b expression, and MPO activity of HL-60 cells increased upon treatment. Finally, viability of HL-60 cells was hampered shown by the depolarization of mitochondria, activation of caspase-3, cleavage of Z-DEVD-aLUC, appearance of the sub-G1 population, and the leakage of the lactate-dehydrogenase into the supernatant. We confirmed the differentiating effect of our drug candidate on human patient-derived AML cells shown by the increase of CD11b and decrease of CD33+, CD7+, CD206+, and CD38^bright cells followed apoptosis (IC₅₀: 80 nM) after treatment ex vivo. Our compound reduced both CD11b+/Ly6C+ and CD11b+/Ly6G+ splenic MDSCs from the murine 4T1 breast cancer model ex vivo.

Synthesis of imatinib, a tyrosine kinase inhibitor, labeled with carbon-14

Imatinib (Gleevec) is a multiple tyrosine kinase inhibitor that decreases the activity of the fusion oncogene called BCR-ABL (breakpoint cluster region protein-Abelson murine leukemia viral oncogene homolog) and is clinically used for the treatment of chronic myelogenous leukemia and acute lymphocytic leukemia. Small molecule drugs, such as imatinib, can bind to several cellular proteins including the target proteins in the cells, inducing undesirable effects along with the effects against the disease. In this study, we report the synthetic optimization for 14 C-labeling and radiosynthesis of [14 C]imatinib to analyze binding with cellular proteins using accelerator mass spectroscopy. 14 C-labeling of imatinib was performed by the synthesis of 14 C-labeld 2-aminopyrimidine intermediate using [14 C]guanidine·HCl, which includes an in situ reduction of an inseparable byproduct for easy purification by HPLC, followed by a cross-coupling reaction with aryl bromide precursor. The radiosynthesis of [14 C]imatinib (specific activity, 631 MBq/mmol; radiochemical purity, 99.6%) was achieved in six steps with a total chemical yield of 29.2%.

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.

Synthesis of Novel Structural Hybrids between Aza-Heterocycles and Azelaic Acid Moiety with a Specific Activity on Osteosarcoma Cells

Nine compounds bearing pyridinyl (or piperidinyl, benzimidazolyl, benzotriazolyl) groups bound to an azelayl moiety through an amide bond were synthesized. The structural analogy with some histone deacetylase inhibitors inspired their syntheses, seeking new selective histone deacetylase inhibitors (HDACi). The azelayl moiety recalls part of 9-hydroxystearic acid, a cellular lipid showing antiproliferative activity toward cancer cells with HDAC as a molecular target. Azelayl derivatives bound to a benzothiazolyl moiety further proved to be active as HDACi. The novel compounds were tested on a panel of both normal and tumor cell lines. Non-specific induction of cytotoxicity was observed in the normal cell line, while three of them induced a biological effect only on the osteosarcoma (U2OS) cell line. One of them induced a change in nuclear shape and size. Cell-cycle alterations are associated with post-transcriptional modification of both H2/H3 and H4 histones. In line with recent studies, revealing unexpected HDAC7 function in osteoclasts, molecular docking studies on the active molecules predicted their proneness to interact with HDAC7. By reducing side effects associated with the action of the first-generation inhibitors, the herein reported compounds, thus, sound promising as selective HDACi.

Study of therapeutic effect of different concentrations of imatinib on Balb/c model of cutaneous leishmaniasis

Leishmaniasis, as a tropical and subtropical disease, is endemic in more than 90 countries around the world. Today, cutaneous leishmaniasis (CL) that affects more than 1.5 million people per year lacks a definitive treatment approach. Imatinib is an anticancer drug that inhibits the abnormal function of Bcr-Abl due to its tyrosine kinase inhibitor, and that was the reason why the drug was tested for CL treatment because protein kinases are essential enzymes in the Leishmania genus. In this study, the L. major CL model of Balb/c mice was produced by injection of the cultured metacyclic form of parasite at the base of the tail. The possible recovery of CL ulcers and determination of the optimum dose of imatinib against Leishmania amastigotes were evaluated. A significant decrease was observed in mice treated with amphotericin B (positive control group) as well as imatinib 50 mg/kg compared to the unreceived drug, negative control group (P<0.05). This study could be promising in gaining insight into the potential of imatinib as an effective treatment approach against CL.

Rational Use of Medicine in Children-The Conflict of Interests Story. A Review

BACKGROUND

United States (US) and European Union (EU) legislation attempts to counterbalance the presumed discrimination in pediatric drug treatment and development.

METHODS

We analyzed the history of drug development, US/EU pediatric laws, and pediatric studies required by US/EU regulatory authorities and reviewed relevant literature.

RESULTS

The US and EU definitions of a child are defined administratively (rather than physiologically) as being aged <17 years and <18 years, respectively. However, children mature physiologically well before their seventeenth or eighteenth birthdays. The semantic blur for these differing definitions may indicate certain conflicts of interest.

CONCLUSIONS

Pediatric healthcare today is better than ever. Regulatory-related requirements for "pediatric" studies focus on labeling. Most of these studies lack medical usefulness and may even harm "pediatric" patients through administration of placebo and/or substandard treatment, despite the resultant publications, networking, patent extensions, and strengthened regulatory standing. Clinicians, parents, and ethics committees should be aware of these issues. New rules are needed to determine new pharmaceutical dose estimates in prepubescent patients, and when/how to clinically confirm them. Internet-based structures to divulge this information should be established between drug developers, clinicians, and regulatory authorities. A prerequisite for the rational use of pharmaceuticals in children would be to correct the flawed concept that children are discriminated against in drug treatment and development, and to abandon separate "pediatric" drug approval processes.

Cardiotoxicity in Hematological Diseases: Are the Tyrosine Kinase Inhibitors Imatinib and Nilotinib Safe?

Chemotherapy-induced cardiotoxicity is a growing concern. The cardiotoxic impact of new drugs such as tyrosine kinase inhibitors is unknown, especially the ones used for chronic myeloid leukemia. We aim to evaluate nilotinib- and imatinib-induced cardiotoxicity. Single-center prospective study of consecutive patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors was conducted during 2015. Patients underwent an initial clinical, laboratorial and echocardiographic evaluation, repeated after 1 year. Eleven patients were included [60.0 (11) years, 63.6% of males; seven patients treated with imatinib and four with nilotinib]. After 1 year of follow-up, all patients remained in functional NYHA class I, with a similar Minnesota quality of life score. Also there was no difference in the biomarkers evaluated (cystatin-C and NT-proBNP). Likewise, no modification in systolic or diastolic function evaluated by echocardiography was observed. All patients presented normal values of longitudinal, circumferential and radial strain in the baseline study, without changes during follow-up. In addition, there were no differences between the two tyrosine kinase inhibitors used, considering all the aforementioned variables. No clinical, laboratory or echocardiographic evidence of nilotinib- and imatinib-induced cardiotoxicity was observed. However, these results should be confirmed in multicenter studies given the low incidence of chronic myeloid leukemia.

Lichen Acids May Be Used as A Potential Drug For Cancer Therapy; by Inhibiting Mitochondrial Thioredoxin Reductase Purified From Rat Lung

Background:

Thioredoxin reductase (E.C 1.6.4.5.; TrxR) is a widely distributed flavoprotein that catalyzes the NADPH-dependent reduction of thioredoxin (Trx) in many cellular events such as DNA synthesis, DNA repair, angiogenesis, antioxidative defense, and regulating apoptosis. Although TrxR is indispensible in protecting cells against oxidative stress, the overexpression of TrxR is seen in many aggressive tumors. Therefore, targeted inhibition of TrxR has been accepted as a new approach for chemotherapy.

Objective:

In this study, in vitro inhibition effect of the lichen acids (diffractaic, evernic, lobaric, lecanoric, and vulpinic acid) on mitochondrial TrxR purified from rat lung was investigated.

Method:

It was the first time the enzyme was purified from rat lungs by using 2’, 5’-ADP Sepharose 4B affinity chromatography. The purity of the enzyme was checked with SDS-PAGE. In vitro inhibition effect of the lichen acids was investigated spectrophotometrically. To emphasize the importance of the obtained data, the commercial anticancer drugs cisplatin and doxorubicin were used as positive controls.

Results:

Molecular mass of the enzyme was calculated as approximately 52.4 kDa. The enzyme was purified with a 63.6% yield, 208.3 fold, and 0.5 EU/mg proteins specific activity. The IC50 values of five lichen acids were significantly lower than IC50 values of anticancer drugs.

Conclusion:

All of the lichen acids, especially lecanoric and vulpinic acid, exhibited much stronger inhibitory effect on TrxR than the anticancer drugs cisplatin and doxorubicin. These lichen acids have pharmacological potential as effective natural antioxidants, antimicrobials, and anticancer agents.

Forgotten public health impacts of cancer - an overview

Cancer is one of the diseases of greatest concern in developed countries and much effort has been invested in discovering and developing therapeutics for curing cancer. Despite the improvements in antineoplastic therapeutics in the last decades, cancer is still one of the most harmful diseases worldwide. The global burden of cancer also implies financial costs: these can be direct costs, such as those related to treatment, care, and rehabilitation and indirect, which include the loss of economic output due to missed work (morbidity costs) and premature death (mortality costs). There are also hidden costs such as health insurance premiums and nonmedical expenses that are worth noting. This paper intends to present an overview of the generally forgotten impacts that the increasing number of cancer cases can have on the environment, workers who handle antineoplastic drugs, and health services. The knowledge available of each of the impacts will be addressed and discussed regarding the expected development. Overall, lessons learnt reflect on the impact of cancer through aspects not commonly evidenced in the literature or even considered in socio-economic analysis, in part due to the fact that these are difficult to contemplate in direct and indirect cancer costs already defined. Attention may be drawn to the need of continuous investment in prevention to reduce the negative impact on the environment, and in the health of workers who handle antineoplastic drugs for patients' treatment.

TKI sensitivity patterns of novel kinase-domain mutations suggest therapeutic opportunities for patients with resistant ALK+ tumors

The anaplastic lymphoma kinase (ALK) protein drives tumorigenesis in subsets of several tumors through chromosomal rearrangements that express and activate its C-terminal kinase domain. In addition, germline predisposition alleles and acquired mutations are found in the full-length protein in the pediatric tumor neuroblastoma. ALK-specific tyrosine kinase inhibitors (TKIs) have become important new drugs for ALK-driven lung cancer, but acquired resistance via multiple mechanisms including kinase-domain mutations eventually develops, limiting median progression-free survival to less than a year. Here we assess the impact of several kinase-domain mutations that arose during TKI resistance selections of ALK+ anaplastic large-cell lymphoma (ALCL) cell lines. These include novel variants with respect to ALK-fusion cancers, R1192P and T1151M, and with respect to ALCL, F1174L and I1171S. We assess the effects of these mutations on the activity of six clinical inhibitors in independent systems engineered to depend on either the ALCL fusion kinase NPM-ALK or the lung-cancer fusion kinase EML4-ALK. Our results inform treatment strategies with a likelihood of bypassing mutations when detected in resistant patient samples and highlight differences between the effects of particular mutations on the two ALK fusions.

Inhibition of Eukaryotic Translation by the Antitumor Natural Product Agelastatin A

Protein synthesis plays an essential role in cell proliferation, differentiation, and survival. Inhibitors of eukaryotic translation have entered the clinic, establishing the translation machinery as a promising target for chemotherapy. A recently discovered, structurally unique marine sponge-derived brominated alkaloid, (-)-agelastatin A (AglA), possesses potent antitumor activity. Its underlying mechanism of action, however, has remained unknown. Using a systematic top-down approach, we show that AglA selectively inhibits protein synthesis. Using a high-throughput chemical footprinting method, we mapped the AglA-binding site to the ribosomal A site. A 3.5 Å crystal structure of the 80S eukaryotic ribosome from S. cerevisiae in complex with AglA was obtained, revealing multiple conformational changes of the nucleotide bases in the ribosome accompanying the binding of AglA. Together, these results have unraveled the mechanism of inhibition of eukaryotic translation by AglA at atomic level, paving the way for future structural modifications to develop AglA analogs into novel anticancer agents.

Biochemical and chemical characterization of Cynara cardunculus L. extract and its potential use as co-adjuvant therapy of chronic myeloid leukemia

ETHNOPHARMACOLOGICAL RELEVANCE

Ancient mediterranean diet was characterized by consuming the spontaneous forms of Cynara cardunculus L. (CCL), commonly called artichoke. Cultivated and/or spontaneous forms of CC studies have demonstrated that methanol extract of CCL flower and/or cynaropicrin showed remarkable anti-proliferative activity in vitro models of leukocyte cancer cell.

AIM OF THE STUDY

Chronic myeloid leukemia (CML) is associated with a reciprocal translocation of the long arms of chromosomes 9 and 22 generating the BCR/ABL fusion gene, translated in the p210^BCR/ABL oncoprotein kinase. This chimeric protein is the target of a kinase inhibitor, imatinib, but the development of mutations in the ABL kinase domain resulting in drug resistance and several approaches to overcoming resistance have been study. In this concern, we investigated the effect of CCL extract on human K562 CML and K562 imatinib resistant (IMAR) cell proliferation and on p210^BCR/ABL expression.

MATERIALS AND METHODS

Chemical characterization of the CCL extracts was performed by GC/MS analysis and semipreparative RP-HPLC chromatography. Structural characterization of compounds was assessed by ¹H-¹³C NMR and LC/MS analysis. The effects of CCL extracts on the proliferation of K562 CML human cell line and K562 IMAR were screened by MTT assay. The p210^BCR/ABL mRNA and protein expressions were analyzed by qRT-PCR and Western blot techniques respectively.

RESULTS

We demonstrate that CCL extract affect cell viability of both K562 CML human cell line and K562 IMAR. The biocomponents of CCL were chemical characterized and we identify cynaropicrin and its deacyl derivative having the capability to down-regulate the p210^BCR/ABL oncoprotein.

CONCLUSIONS

Our study suggests that the use of those molecules could represent a novel and promising strategy to potentiate the ability of imatinib or of its analogues to induce cancer growth arrest in CML and to delay or overcome the resistance of CML to chemotherapy.

Combined cyto/genotoxic activity of a selected antineoplastic drug mixture in human circulating blood cells

Antineoplastic drugs are highly cytotoxic chemotherapeutic agents that can often interfere directly or indirectly with the cell's genome. In an environmental or medical setting simultaneous exposure may occur. Such multiple exposures may pose a higher risk than it could be assumed from the studies evaluating the effect of a single substance. Therefore, in the present study we tested the combined cyto/genotoxicity of a mixture of selected antineoplastic drugs with different mechanisms of action (5-fluorouracil, etoposide, and imatinib mesylate) towards human lymphocytes in vitro. The results suggest that the selected antineoplastic drug mixture is potentially cyto/genotoxic and that it can induce cell and genome damage even at low concentrations. Moreover, the changes in the measured oxidative stress parameters suggest the participation of reactive oxygen species in the cyto/genotoxicity of the selected mixture. The obtained results indicate not only that such mixtures may pose a risk to cell and genome integrity, but also that single compound toxicity data are not sufficient for the predicting toxicity in a complex environment. Altogether, the results emphasise the need for further toxicological screening of antineoplastic drug mixtures, especially at low environmentally relevant concentrations, as to avoid any possible adverse effects on the environment and human health.

Impact of CYP3A4*18 and CYP3A5*3 Polymorphisms on Imatinib Mesylate Response Among Chronic Myeloid Leukemia Patients in Malaysia

Introduction

Imatinib mesylate (IM), a selective inhibitor of the BCR-ABL tyrosine kinase, is a well-established first-line treatment for chronic myeloid leukemia (CML). IM is metabolized mainly by cytochrome P450 (CYP) in the liver, specifically the CYP3A4 and CYP3A5 enzymes. Polymorphisms in these genes can alter the enzyme activity of IM and may affect its response. In this study, the impact of two single-nucleotide polymorphisms (SNPs), CYP3A5*3 (6986A>G) and CYP3A4*18 (878T>C), on IM treatment response in CML patients (n = 270; 139 IM resistant and 131 IM good responders) was investigated.

Methods

Genotyping of CYP3A4*18 and CYP3A5*3 was performed using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) technique. The association between allelic variants and treatment response was assessed by means of odds ratio (OR) with 95% confidence intervals calculated by logistic regression.

Results

Our results indicated that CML patients carrying the heterozygous (AG) and homozygous variant (GG) genotype of CYP3A5*3 were associated with a significantly lower risk of acquiring resistance with OR 0.171; 95% CI: 0.090–0.324, p < 0.001 and OR 0.257; 95% CI: 0.126–0.525, p < 0.001, respectively. Although CML patients carrying the heterozygous (TC) genotype of CYP3A4*18 showed a lower risk of acquiring resistance toward IM (OR 0.648; 95% CI: 0.277–1.515), the association was not statistically significant (p = 0.316). No homozygous variant (CC) genotype of CYP3A4*18 was detected among the CML patients.

Conclusion

It is concluded that polymorphism of CYP3A5*3 is associated with IM treatment response in Malaysian CML patients with carriers of CYP3A5*1/*3 and CYP3A5*3/*3 genotypes posing lower risk for development of resistance to IM.

Leukocytosis and Leukemia

Leukocytosis is among the most common findings on peripheral blood smear. A wide range of causes may mediate this finding, and careful clinical and laboratory evaluation assist in differentiating between benign and malignant causes of increased white blood cell counts. In this article, various nonmalignant causes are explored, including infectious, inflammatory, autoimmune, and allergic. In addition, malignant causes of leukocytosis are discussed, including myeloproliferative disorders, acute leukemia, and chronic leukemia, as well as treatment and monitoring for patients with these diseases.

Thermal stability and decompositions kinetics under non-isothermal conditions of imatinib mesylate α form

The thermal decomposition and kinetic parameters of synthetized imatinib mesylate α form α form were determined by thermogravimetry (TGA/DTG) under non-isothermal conditions. The experiments were performed at a 25-940°C temperature range at five different heating rates: 2.5Kmin(-1), 5Kmin(-1), 10Kmin(-1), 15Kmin(-1) and 20Kmin(-1) per minute in a nitrogen atmosphere. Imatinib mesylate α form presents one-step mass loss during the degradation process. The thermal stability of the examined material, the melting temperature (Tonset=220.6°C) and ΔH fusion=-95.74Jg(-1) at a heating rate of 10°Cmin(-1) was established. The values of activation energies have been estimated using Kissinger, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods.

Formulation and in vitro, in vivo evaluation of effervescent floating sustained-release imatinib mesylate tablet

Introduction

Imatinib mesylate is an antineoplastic agent which has high absorption in the upper part of the gastrointestinal tract (GIT). Conventional imatinib mesylate (Gleevec) tablets produce rapid and relatively high peak blood levels and requires frequent administration to keep the plasma drug level at an effective range. This might cause side effects, reduced effectiveness and poor therapeutic management. Therefore, floating sustained-release Imatinib tablets were developed to allow the tablets to be released in the upper part of the GIT and overcome the inadequacy of conventional tablets.

Methodology

Floating sustained-release Imatinib mesylate tablets were prepared using the wet granulation method. Tablets were formulated using Hydroxypropyl Methylcellulose (HPMC K4M), with Sodium alginate (SA) and Carbomer 934P (CP) as release-retarding polymers, sodium bicarbonate (NaHCO₃) as the effervescent agent and lactose as a filler. Floating behavior, in vitro drug release, and swelling index studies were conducted. Initial and total drug release duration was compared with a commercial tablet (Gleevec) in 0.1 N HCl (pH 1.2) at 37 ± 0.5°C for 24 hours. Tablets were then evaluated for various physical parameters, including weight variation, thickness, hardness, friability, and drug content. Consequently, 6 months of physical stability studies and in vitro gastro-retentive studies were conducted.

Results and Discussion

Statistical data analysis revealed that tablets containing a composition of 14.67% w/w HPMC K4M, 10.67%, w/w Na alginate, 1.33%, w/w Carbomer 934P and 9.33%, w/w NaHCO₃ produced the most favorable formulation to develop 24-hour sustained-release tablets with optimum floating behavior and satisfactory physicochemical characteristics. Furthermore, in vitro release study revealed that the formulated SR tablet had significantly lower C_max and higher T_max compared to the conventional tablet (Gleevec). Thus, formulated SR tablets preserved persistent concentration of plasma up to 24 hours.

Conclusion

In conclusion, in order to suggest a better drug delivery system with constant favorable release, resulting in optimized absorption and less side effects, formulated CP-HPMC-SA based imatinib mesylate floating sustained-release tablets can be a promising candidate for cancer chemotherapy.

A novel benzimidazole derivative binds to the DNA minor groove and induces apoptosis in leukemic cells

In the present study, we have synthesized various benzimidazole derivatives, evaluated their potential to act as DNA minor groove binder and tested their chemotherapeutic efficacy.

Differential and opposing effects of imatinib on LPS- and ventilator-induced lung injury

Endothelial dysfunction underlies the pathophysiology of vascular disorders such as acute lung injury (ALI) syndromes. Recent work has identified the Abl family kinases (c-Abl and Arg) as important regulators of endothelial cell (EC) barrier function and suggests that their inhibition by currently available pharmaceutical agents such as imatinib may be EC protective. Here we describe novel and differential effects of imatinib in regulating lung pathophysiology in two clinically relevant experimental models of ALI. Imatinib attenuates endotoxin (LPS)-induced vascular leak and lung inflammation in mice but exacerbates these features in a mouse model of ventilator-induced lung injury (VILI). We next explored these discrepant observations in vitro through investigation of the roles for Abl kinases in cultured lung EC. Imatinib attenuates LPS-induced lung EC permeability, restores VE-cadherin junctions, and reduces inflammation by suppressing VCAM-1 expression and inflammatory cytokine (IL-8 and IL-6) secretion. Conversely, in EC exposed to pathological 18% cyclic stretch (CS) (in vitro model of VILI), imatinib decreases VE-cadherin expression, disrupts cell-cell junctions, and increases IL-8 levels. Downregulation of c-Abl expression with siRNA attenuates LPS-induced VCAM-1 expression, whereas specific reduction of Arg reduces VE-cadherin expression in 18% CS-challenged ECs to mimic the imatinib effects. In summary, imatinib exhibits pulmonary barrier-protective and anti-inflammatory effects in LPS-injured mice and lung EC; however, imatinib exacerbates VILI as well as dysfunction in 18% CS-EC. These findings identify the Abl family kinases as important modulators of EC function and potential therapeutic targets in lung injury syndromes.

BreaKmer: detection of structural variation in targeted massively parallel sequencing data using kmers

Genomic structural variation (SV), a common hallmark of cancer, has important predictive and therapeutic implications. However, accurately detecting SV using high-throughput sequencing data remains challenging, especially for ‘targeted’ resequencing efforts. This is critically important in the clinical setting where targeted resequencing is frequently being applied to rapidly assess clinically actionable mutations in tumor biopsies in a cost-effective manner. We present BreaKmer, a novel approach that uses a ‘kmer’ strategy to assemble misaligned sequence reads for predicting insertions, deletions, inversions, tandem duplications and translocations at base-pair resolution in targeted resequencing data. Variants are predicted by realigning an assembled consensus sequence created from sequence reads that were abnormally aligned to the reference genome. Using targeted resequencing data from tumor specimens with orthogonally validated SV, non-tumor samples and whole-genome sequencing data, BreaKmer had a 97.4% overall sensitivity for known events and predicted 17 positively validated, novel variants. Relative to four publically available algorithms, BreaKmer detected SV with increased sensitivity and limited calls in non-tumor samples, key features for variant analysis of tumor specimens in both the clinical and research settings.