The development of imatinib as a therapeutic agent for chronic myeloid leukemia

Protein kinase inhibitor-based cancer therapies: Considering the potential of nitric oxide (NO) to improve cancer treatment

The deregulation of a wide variety of protein kinases is associated with cancer cell initiation and tumor progression. Owing to their indispensable function in signaling pathways driving malignant cell features, protein kinases constitute major therapeutic targets in cancer. Over the past two decades, intense efforts in drug development have been dedicated to this field. The development of protein kinase inhibitors (PKIs) have been a real breakthrough in targeted cancer therapy. Despite obvious successes across patients with different types of cancer, the development of PKI resistance still prevails. Combination therapies are part of a comprehensive approach to address the problem of drug resistance. The therapeutic use of nitric oxide (NO) donors to bypass PKI resistance in cancer has never been tested in clinic yet but several arguments suggest that the combination of PKIs and NO donors may exert a potential anticancer effect. The present review summarized the current state of knowledge on common targets to both PKIs and NO. Herein, we attempt to provide the rationale underlying a potential combination of PKIs and NO donors for future directions and design of new combination therapies in cancer.

ArtiFuse-computational validation of fusion gene detection tools without relying on simulated reads

MOTIVATION

Gene fusions are an important class of transcriptional variants that can influence cancer development and can be predicted from RNA sequencing (RNA-seq) data by multiple existing tools. However, the real-world performance of these tools is unclear due to the lack of known positive and negative events, especially with regard to fusion genes in individual samples. Often simulated reads are used, but these cannot account for all technical biases in RNA-seq data generated from real samples.

RESULTS

Here, we present ArtiFuse, a novel approach that simulates fusion genes by sequence modification to the genomic reference, and therefore, can be applied to any RNA-seq dataset without the need for any simulated reads. We demonstrate our approach on eight RNA-seq datasets for three fusion gene prediction tools: average recall values peak for all three tools between 0.4 and 0.56 for high-quality and high-coverage datasets. As ArtiFuse affords total control over involved genes and breakpoint position, we also assessed performance with regard to gene-related properties, showing a drop-in recall value for low-expressed genes in high-coverage samples and genes with co-expressed paralogues. Overall tool performance assessed from ArtiFusions is lower compared to previously reported estimates on simulated reads. Due to the use of real RNA-seq datasets, we believe that ArtiFuse provides a more realistic benchmark that can be used to develop more accurate fusion gene prediction tools for application in clinical settings.

AVAILABILITY AND IMPLEMENTATION

ArtiFuse is implemented in Python. The source code and documentation are available at https://github.com/TRON-Bioinformatics/ArtiFusion.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

The Bone Marrow Niche - The Tumor Microenvironment That Ensures Leukemia Progression

The human body requires a constant delivery of fresh blood cells that are needed to maintain body homeostasis. Hematopoiesis is the process that drives the formation of new blood cells from a single stem cell. This is a complex, orchestrated and tightly regulated process that occurs within the bone marrow. When such process is faulty or deregulated, leukemia arises, develops and thrives by subverting normal hematopoiesis and availing the supplies of this rich milieu.In this book chapter we will describe and characterize the bone marrow microenvironment and its key importance for leukemia expansion. The several components of the bone marrow niche, their interaction with the leukemic cells and the cellular pathways activated within the malignant cells will be emphasized. Finally, novel therapeutic strategies to target this sibling interaction will also be discussed.

Diarylamides in anticancer drug discovery: A review of pre-clinical and clinical investigations

Several diarylamide compounds have been highlighted as potential anticancer agents. Among them, imatinib, dasatinib, and nilotinib have been marketed for treatment of chronic myeloid leukemia (CML). CML is a cancer type that originates in specific cells in bone marrow and is considered as life-threating disease. Imatinib is the first generation of tyrosine kinase inhibitor (TKI) to be approved for treatment of CML. Second generation drugs, dasatinib and nilotinib, were introduced for patients that are resistant or intolerant to imatinib therapy. Second generation drugs induce faster responses with fewer side effects when compared to imatinib. In this literature review, we reviewed recent advances of diarylamide anticancer agents, including first and second generation drugs treating CML and their other uses, in addition to other compounds that are still in preclinical phases. This review focuses on the reports published in the literature from 2010 to 2019.

Evaluation of oxidative stress responses in human circulating blood cells after imatinib mesylate treatment - Implications to its mechanism of action

Imatinib mesylate (IM) is the first developed protein kinase inhibitor and recently it has topped consumption rates among targeted and total anticancer drugs. Although there are indications that IM possesses cyto/genotoxic activities against normal non-target cells as well, there is a lack of information regarding the underlying mechanism involved in those actions. Therefore, we aimed to evaluate the response of human circulating blood cells towards oxidative stress after IM treatment (0.0001–10 µg/mL) in vitro. Based on the results, IM had an influence on all of the oxidative stress parameters tested. Lower concentrations of IM induced an increase of glutathione level, following its decrease at higher IM concentrations indicating impairment in oxidative stress defences. Concomitant to a glutathione decrease, an increase of malondialdehyde and protein carbonyls level was observed indicating oxidative damage of lipids and proteins. The observed effects overlapped with the observed formation of oxidative base damage detected by formamidopyrimidine-DNA glycosylase modified-comet assay indicating that IM managed to induce oxidative DNA damage. Our results provide novelty in their mechanistic approach to IM-induced toxicity in non-target cells and suggest that IM can affect blood cells and induce oxidative stress.

Simultaneous Inhibition of BCR-ABL1 Tyrosine Kinase and PAK1/2 Serine/Threonine Kinase Exerts Synergistic Effect against Chronic Myeloid Leukemia Cells

Tyrosine kinase inhibitors (TKIs) revolutionized the treatment of chronic myeloid leukemia in the chronic phase (CML-CP). However, it is unlikely that they can completely “cure” the disease. This might be because some subpopulations of CML-CP cells such as stem and progenitor cells are resistant to chemotherapy, even to the new generation of TKIs. Therefore, it is important to look for new methods of treatment to improve therapeutic outcomes. Previously, we have shown that class I p21-activated serine/threonine kinases (PAKs) remained active in TKI-naive and TKI-treated CML-CP leukemia stem and early progenitor cells. In this study, we aimed to determine if simultaneous inhibition of BCR-ABL1 oncogenic tyrosine kinase and PAK1/2 serine/threonine kinase exert better anti-CML effect than that of individual treatments. PAK1 was inhibited by small-molecule inhibitor IPA-3 (p21-activated kinase inhibitor III), PAK2 was downregulated by specific short hairpin RNA (shRNA), and BCR-ABL1 tyrosine kinase was inhibited by imatinib (IM). The studies were conducted by using (i) primary CML-CP stem/early progenitor cells and normal hematopoietic counterparts isolated from the bone marrow of newly diagnosed patients with CML-CP and from healthy donors, respectively, (ii) CML-blast phase cell lines (K562 and KCL-22), and (iii) from BCR-ABL1-transformed 32Dcl3 cell line. Herein, we show that inhibition of the activity of PAK1 and/or PAK2 enhanced the effect of IM against CML cells without affecting the normal cells. We observed that the combined use of IM with IPA-3 increased the inhibition of growth and apoptosis of leukemia cells. To evaluate the type of interaction between the two drugs, we performed median effect analysis. According to our results, the type and strength of drug interaction depend on the concentration of the drugs tested. Generally, combination of IM with IPA-3 at the 50% of the cell kill level (EC50) generated synergistic effect. Based on our results, we hypothesize that IM, a BCR-ABL1 tyrosine kinase inhibitor, combined with a PAK1/2 inhibitor facilitates eradication of CML-CP cells.

Insights into the success and failure of systemic therapy for hepatocellular carcinoma

Systemic treatment for hepatocellular carcinoma (HCC) has been boosted by the incorporation of new agents after many negative phase III trials in the decade since the approval of sorafenib. Sorafenib introduced the concept that targeting specific hallmarks of hepatocarcinogenesis could modify the dismal prognosis of this disease, with the drug remaining a cornerstone in the upfront therapy for advanced HCC. The design of clinical trials in this malignancy is complicated by important obstacles related to patient selection, prognostic assessment and the need for endpoints that correlate with improvement in survival outcomes. In addition, the currently used criteria to determine treatment response or progression might prevent physicians from making appropriate clinical judgements and interpreting evidence arising from trials. In this Review, we discuss the advances in systemic therapy for HCC and critically review trial designs in HCC. Although novel therapies, such as new targeted agents and immunotherapies, are being rapidly incorporated, it is paramount to design future clinical trials based on the lessons learned from past failures and successes.

Synthesis, Biological Activities and Docking Studies of Novel 4-(Arylaminomethyl)benzamide Derivatives as Potential Tyrosine Kinase Inhibitors

A number of new compounds containing the 4-(aminomethyl)benzamide fragment as a linker were designed and synthesized, and their biological activities were evaluated as potential anticancer agents. The cytotoxicity activity of the designed compounds was studied in two hematological and five solid cell lines in comparison with the reference drugs. Targeted structures against eight receptor tyrosine kinases including EGFR, HER-2, HER-4, IGF1R, InsR, KDR, PDGFRa, and PDGFRb were investigated. The majority of the compounds showed a potent inhibitory activity against the tested kinases. The analogues 11 and 13 with the (trifluoromethyl)benzene ring in the amide or amine moiety of the molecule were proven to be highly potent against EGFR, with 91% and 92% inhibition at 10 nM, respectively. The docking of synthesized target compounds for nine protein kinases contained in the Protein Data Bank (PDB) database was carried out. The molecular modeling results for analogue 10 showed that the use of the 4-(aminomethyl)benzamide as a flexible linker leads to a favorable overall geometry of the molecule, which allows one to bypass the bulk isoleucine residue and provides the necessary binding to the active center of the T315I-mutant Abl (PDB: 3QRJ).

Integrated systems-genetic analyses reveal a network target for delaying glioma progression

Objective

To identify a convergent, multitarget proliferation characteristic for astrocytoma transformation that could be targeted for therapy discovery.

Methods

Using an integrated functional genomics approach, we prioritized networks associated with astrocytoma progression using the following criteria: differential co‐expression between grade II and grade III IDH1‐mutated and 1p/19q euploid astrocytomas, preferential enrichment for genetic risk to cancer, association with patient survival and sample‐level genomic features. Drugs targeting the identified multitarget network characteristic for astrocytoma transformation were computationally predicted using drug transcriptional perturbation data and validated using primary human astrocytoma cells.

Results

A single network, M2, consisting of 177 genes, was associated with glioma progression on the basis of the above criteria. Functionally, M2 encoded physically interacting proteins regulating cell cycle processes and analysis of genome‐wide gene‐regulatory interactions using mutual information and DNA–protein interactions revealed the known regulators of cell cycle processes FoxM1, B‐Myb, and E2F2 as key regulators of M2. These results suggest functional disruption of M2 via gene mutation or altered expression as a convergent pathway regulating astrocytoma transformation. By considering M2 as a multitarget drug target regulating astrocytoma transformation, we identified several drugs that are predicted to restore M2 expression in anaplastic astrocytoma toward its low‐grade profile and of these, we validated the known antiproliferative drug resveratrol as down‐regulating multiple nodes of M2 including at nanomolar concentrations achievable in human cerebrospinal fluid by oral dosing.

Interpretation

Our results identify M2 as a multitarget network characteristic for astrocytoma progression and encourage M2‐based drug screening to identify new compounds for preventing glioma transformation.

Modular Continuous Flow Synthesis of Imatinib and Analogues

A modular continuous flow synthesis of imatinib and analogues is reported. Structurally diverse imatinib analogues are rapidly generated using three readily available building blocks via a flow hydration/chemoselective C-N coupling sequence. The newly developed continuous flow hydration and amidation modules each exhibit a broad scope with good to excellent yields. Overall, the method described does not require solvent switches, in-line purifications, or packed-bed apparatuses due to the judicious manipulation of flow setups and solvent mixtures.

Regulatory Molecules and Corresponding Processes of BCR-ABL Protein Degradation

The BCR-ABL fusion protein with strong tyrosine kinase activity is one of the molecular biological bases of leukemia. Imatinib (Gleevec), a specific targeted drug for the treatment of chronic myeloid leukemia (CML), was developed for inhibiting the kinase activity of the BCR-ABL fusion protein. Despite the positive clinical efficacy of imatinib, the proportion of imatinib resistance has gradually increased. The main reason for the resistance is a decrease in sensitivity to imatinib caused by mutation or amplification of the BCR-ABL gene. In response to this phenomenon, the new generation of tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL fusion protein was developed to solve the problem. However this strategy only selectively inhibits the tyrosine kinase activity of the BCR-ABL protein without eliminating the BCR-ABL protein, it does not fundamentally cure the BCR-ABL-positive leukemia patients. With the accumulation of the knowledge of cellular molecular biology, it has become possible to specifically eliminate certain proteins by cellular proteases in a specific way. Therefore, the therapeutic strategy to induce the degradation of the BCR-ABL fusion protein is superior to the strategy of inhibiting its activity. The protein degradation strategy is also a solution to the TKI resistance caused by different BCR-ABL gene point mutations. In order to provide possible exploration directions and clues for eliminating the BCR-ABL fusion protein in tumor cells, we summarize the significant molecules involved in the degradation pathway of the BCR-ABL protein, as well as the reported potent compounds that can target the BCR-ABL protein for degradation.

Imatinib Mesylate

Imatinib mesylate (Gleevec, Glivec [Novartis, Basel, Switzerland], formerly referred to as STI571 or CGP57148B) represents the paradigm of a new class of anticancer agents, so-called small molecules. They have a high selectivity against a specific molecular target known to be the cause for the establishment and maintenance of the malignant phenotype. Imatinib is a rationally designed oral signal transduction inhibitor that specifically targets several protein tyrosine kinases, Abl, Arg (Abl-related gene), the stem cell factor receptor (c-KIT), platelet-derived growth factor receptor (PDGF-R), and their oncogenic forms, most notably BCR-ABL. Imatinib has been shown to have remarkable clinical activity in patients with chronic myeloid leukemia (CML) and malignant gastrointestinal stroma tumors (GIST) leading to its approval for treatment of these diseases. Treatment with imatinib is generally well tolerated with a low incidence of severe side effects. The most common adverse events include mild to moderate edema, muscle cramps, diarrhea, nausea, skin rashes, and myelosuppression. Several mechanisms of resistance have been identified. Clonal evolution, amplification, or overexpression of BCR-ABL as well as mutations in the catalytic domain, P-loop, and other mutations have been demonstrated to play a role in primary and secondary resistance to imatinib, respectively. Understanding of the underlying mechanisms of resistance has led to the development of new second- and third-generation tyrosine kinase inhibitors (see chapters on dasatinib, nilotinib, bosutinib, and ponatinib).

Imatinib mesylate does not counteract ovarian tissue fibrosis in postnatal rat ovary

Chemotherapy may result in ovarian atrophy, a depletion of the primordial follicle pool, diminished ovarian weight, cortical and stromal fibrosis. Imatinib mesylate is an anticancer agent that inhibits competitively several receptor tyrosine kinases (RTKs). RTKs play important roles in cell metabolism, proliferation, and apoptosis. In clinic, imatinib mesylate is also known as an anti-fibrotic medicine. In the present study, the impact of imatinib on the ovarian tissue was investigated by assessing ovarian tissue fibrosis in postnatal rat administered with or without imatinib for three days. Fibrosis in the ovarian tissue was determined by histology (Picrosirius and Masson's trichrome staining) and the protein expression of vimentin and alpha-smooth muscle actin (α-SMA). Furthermore, mRNA expression of Forkhead box transcription factor O1 and O3 (FOXO1 and FOXO3), which are markers of cell proliferation was quantified. A short-term exposure to imatinib showed to increase tissue fibrosis in ovaries. This was observed by Masson's trichrome staining. Exposure to imatinib led also to a down-regulation of vimentin protein expression and up-regulation mRNA expression of FOXO3. This may indicate a role of FOXO3 in ovarian tissue fibrosis in postnatal rat ovaries.

Novel Score-based Decision Approach in Chronic Myeloid Leukemia Patients After Acute Toxic Imatinib-induced Liver Injury

The tyrosine kinase inhibitor (TKI) imatinib in rare cases can cause acute toxic hepatitis, hepatic failure, and death. Currently, the choice of further chronic myeloid leukemia (CML) therapy in patients after acute hepatotoxicity is still a difficult question, which requires a complex individual approach based on the clinical guidelines of adverse event management. Data about the further follow-up strategy approach in patients with CML after acute toxic imatinib-induced liver injury are of concern, and at times controversial. In addition, one of the questions is about the necessity and safety of the imatinib therapy resumption after acute hepatotoxicity. In some publications, imatinib resumption without the recurrence of hepatotoxicity has been discussed; in others, imatinib resumption with the recurrence of imatinib hepatotoxicity has been mentioned. There are a few publications about the experience of administration of the second-line TKIs after acute imatinib hepatotoxicity. There are no clear data on which factors the physician's decision should be based on in patients with CML after acute toxic imatinib-induced liver injury. Imatinib should be restarted or withdrawn, when and for whom second-line therapy should be started. The physician's decision is usually based on the published data of similar cases, personal experience, and the severity of hepatotoxicity. We have discussed the clinical guidelines devoted to the peculiarities of the patient's management after acute toxic imatinib-induced hepatitis and main strategy approaches. A complex score-based decision algorithm for choosing the further strategy approach after acute toxic imatinib-induced hepatitis in patients with CML has been presented. The following parameters should be assessed: the grade of hepatotoxicity reaction, the presence of liver transplantation or imatinib-induced liver cirrhosis and its possible pathogenetic mechanism, the presence of early molecular response (EMR) to imatinib therapy defined as three-month BCR-ABL1 ≤10% according to the international scale (BCR-ABL1^IS ) or/and six-month BCR-ABL1 ^IS <1%; and the presence of the offender concomitant drug that probably caused the drug interaction with imatinib and the presence of viral hepatitis reactivation identified by polymerase chain reaction (PCR).

Efficacy of targeted liposomes and nanocochleates containing imatinib plus dexketoprofen against fibrosarcoma

The main challenges in treating cancer using chemotherapeutics are insufficient dose at the target site and the development of drug resistance, while higher doses can induce side effects by damaging nontarget tissues. Combinatorial drug therapy may overcome these limitations by permitting lower doses and more specific targeting, thereby mitigating drug resistance and nontarget side effects. Recent reports indicate that nonsteroidal anti-inflammatory drugs (NSAIDs) have anticancer potential and can be used together with conventional chemotherapeutics to improve efficacy and safety. In the present study, imatinib mesylate and dexketoprofen trometamol were selected as model drugs to develop targeted surface-modified liposome and nanocochleate formulations for fibrosarcoma treatment. The physicochemical properties and in vitro efficacy of various formulations were evaluated by measurement of particle size distribution, polydispersity index, zeta potential, encapsulation efficiency, diffusion through Caco-2 cells, and toxicity in culture. Selected formulations were then evaluated in fibrosarcoma-bearing model mice by histopathological observations and tyrosine kinase receptor inhibition assays. The most effective formulation on the fibrosarcoma model was a PEGylated nanocochleate formulation. These findings provide a foundation for developing more effective formulations and chemotherapeutic strategies for the treatment of fibrosarcoma and other types of cancer.

A numerical approach for a discrete Markov model for progressing drug resistance of cancer

The presence of treatment-resistant cells is an important factor that limits the efficacy of cancer therapy, and the prospect of resistance is considered the major cause of the treatment strategy. Several recent studies have employed mathematical models to elucidate the dynamics of generating resistant cancer cells and attempted to predict the probability of emerging resistant cells. The purpose of this paper is to present numerical approach to compute the number of resistant cells and the emerging probability of resistance. Stochastic model was designed and developed a method to approximately but efficiently compute the number of resistant cells and the probability of resistance. To model the progression of cancer, a discrete-state, two-dimensional Markov process whose states are the total number of cells and the number of resistant cells was employed. Then exact analysis and approximate aggregation approaches were proposed to calculate the number of resistant cells and the probability of resistance when the cell population reaches detection size. To confirm the accuracy of computed results of approximation, relative errors between exact analysis and approximation were computed. The numerical values of our approximation method were very close to those of exact analysis calculated in the range of small detection size M = 500, 100, and 1500. Then computer simulation was performed to confirm the accuracy of computed results of approximation when the detection size was M = 10000,30000,50000,100000 and 1000000. All the numerical results of approximation fell between the upper level and the lower level of 95% confidential intervals and our method took less time to compute over a broad range of cell size. The effects of parameter change on emerging probabilities of resistance were also investigated by computed values using approximation method. The results showed that the number of divisions until the cell population reached the detection size is important for emerging the probability of resistance. The next step of numerical approach is to compute the emerging probabilities of resistance under drug administration and with multiple mutation. Another effective approximation would be necessary for the analysis of the latter case.

Covalently Crosslinked Nanogels: An NMR Study of the Effect of Monomer Reactivity on Composition and Structure

Covalently crosslinked nanogels are widely explored as drug delivery systems and sensors. Radical polymerization provides a simple, inexpensive, and broadly applicable approach for their preparation, although the random nature of the reaction requires careful study of the final chemical composition. We demonstrate how the different reactivities of the monomers influence the total degree of incorporation into the polymer matrix and the role played by the experimental parameters in maximizing polymerization efficiency. Nanogels based on N-isopropylacrylamide, N-n-propylacrylamide, and acrylamide crosslinked with N,N'-methylenebisacrylamide were included in this study, in combination with functional monomers N-acryloyl-l-proline, 2-acrylamido-2-methyl-1-propanesulfonic acid, and 4-vinyl-1H-imidazole. Total monomer concentration and initiator quantities are determining parameters for maximizing monomer conversions and chemical yields. The results show that the introduction of functional monomers, changes in the chemical structure of the polymerizable unit, and the addition of templating molecules can all have an effect on the polymerization kinetics. This can significantly impact the final composition of the matrices and their chemical structure, which in turn influence the morphology and properties of the nanogels.

Midostaurin: its odyssey from discovery to approval for treating acute myeloid leukemia and advanced systemic mastocytosis

Midostaurin was a prototype kinase inhibitor, originally developed as a protein kinase C inhibitor and subsequently as an angiogenesis inhibitor, based on its inhibition of vascular endothelial growth factor receptor. Despite promising preclinical data, early clinical trials in multiple diseases showed only modest efficacy. In 1996, the relatively frequent occurrence of fms-like tyrosine kinase 3 (FLT3) activating mutations in acute myeloid leukemia (AML) was first recognized. Several years later, midostaurin was discovered to be a potent inhibitor of the FLT3 tyrosine kinase and to have activity against mutant forms of KIT proto-oncogene receptor tyrosine kinase, which drive advanced systemic mastocytosis (SM). Through a series of collaborations between industry and academia, midostaurin in combination with standard chemotherapy was evaluated in the Cancer and Leukemia Group B 10603/RATIFY study, a large, phase 3, randomized, placebo-controlled trial in patients with newly diagnosed FLT3-mutated AML. This was the first study to show significant improvements in overall survival and event-free survival with the addition of a targeted therapy to standard chemotherapy in this population. Around the same time, durable responses were also observed in other trials of midostaurin in patients with advanced SM. Collectively, these clinical data led to the approval of midostaurin by the US Food and Drug Administration and the European Medicines Agency for both newly diagnosed FLT3-mutated AML and advanced SM.

Approaches to the Structure-Based Design of Antivirulence Drugs: Therapeutics for the Post-Antibiotic Era

The alarming rise of multidrug-resistant bacterial strains, coupled with decades of stagnation in the field of antibiotic development, necessitates exploration of new therapeutic approaches to treat bacterial infections. Targeting bacterial virulence is an attractive alternative to traditional antibiotics in that this approach disarms pathogens that cause human diseases, without placing immediate selective pressure on the target bacterium or harming commensal species. The growing number of validated virulence protein targets for which structural information has been obtained, along with advances in computational power and screening algorithms, make the rational design of antivirulence drugs a promising avenue to explore. Here, we review the principles of structure-based drug design and the exciting opportunities this technique presents for antivirulence drug discovery.

BCR-Abl Silencing by siRNA: A Potent Approach to Sensitize Chronic Myeloid Leukemia Cells to Tyrosine Kinase Inhibitor Therapy

Nonviral gene therapy with specific short interfering RNAs (siRNAs) against BCR-Abl can be an alternative and/or supportive therapy of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors (TKIs), given the often observed resistance to TKIs in clinical setting. In this study, we explored the feasibility of BCR-Abl siRNA therapy in CML K562 cells in vitro by employing a cationic polymer derived from cholesterol (Chol) grafted low-molecular weight polyethyleneimine (PEI). The first generation TKI imatinib upregulated the expression of BCR-Abl in K562 cells as expected. Delivery of BCR-Abl siRNA in both drug-sensitive and drug-resistant K562 cells significantly downregulated the mRNA levels in both cell types. Similarly, the BCR-Abl siRNA treatment arrested the growth of both drug-sensitive and drug-resistant K562 cells with no obvious differences despite a large difference in drug responsiveness. The BCR-Abl gene silencing in combination with TKI treatments exhibited significant synergism in drug-resistant K562 cells in generating substantial antileukemic activity, where the TKIs on their own were not effective. The effect of BCR-Abl siRNA and TKIs on non-CML cells (Jurkat and primary fibroblast) was negligible, indicating the specificity of the proposed therapy. This strategy can significantly overcome TKI resistance in CML cells, suggesting a feasible and effective treatment model for CML patients suffering from clinical resistances.

A Structural View on Medicinal Chemistry Strategies against Drug Resistance

The natural phenomenon of drug resistance is a widespread issue that hampers the performance of drugs in many major clinical indications. Antibacterial and antifungal drugs are affected, as well as compounds for the treatment of cancer, viral infections, or parasitic diseases. Despite the very diverse set of biological targets and organisms involved in the development of drug resistance, the underlying molecular mechanisms have been identified to understand the emergence of resistance and to overcome this detrimental process. Detailed structural information on the root causes for drug resistance is nowadays frequently available, so next-generation drugs can be designed that are anticipated to suffer less from resistance. This knowledge-based approach is essential for fighting the inevitable occurrence of drug resistance.

Anti-growth Effects of Imatinib and GNF5 via Regulation of Skp2 in Human Hepatocellular Carcinoma Cells

Background

Human hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells.

Methods

Cell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated.

Results

Imatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5.

Conclusions

These results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

The Identification and Interpretation of cis-Regulatory Noncoding Mutations in Cancer

In the need to characterise the genomic landscape of cancers and to establish novel biomarkers and therapeutic targets, studies have largely focused on the identification of driver mutations within the protein-coding gene regions, where the most pathogenic alterations are known to occur. However, the noncoding genome is significantly larger than its protein-coding counterpart, and evidence reveals that regulatory sequences also harbour functional mutations that significantly affect the regulation of genes and pathways implicated in cancer. Due to the sheer number of noncoding mutations (NCMs) and the limited knowledge of regulatory element functionality in cancer genomes, differentiating pathogenic mutations from background passenger noise is particularly challenging technically and computationally. Here we review various up-to-date high-throughput sequencing data/studies and in silico methods that can be employed to interrogate the noncoding genome. We aim to provide an overview of available data resources as well as computational and molecular techniques that can help and guide the search for functional NCMs in cancer genomes.

Precision Medicine: Changing the way we think about healthcare

Health care has changed since the decline in mortality caused by infectious diseases as well as chronic and non-contagious diseases, with a direct impact on the cost of public health and individual health care. We must now transition from traditional reactive medicine based on symptoms, diagnosis and treatment to a system that targets the disease before it occurs and, if it cannot be avoided, treats the disease in a personalized manner. Precision Medicine is that new way of thinking about medicine. In this paper, we performed a thorough review of the literature to present an updated review on the subject, discussing the impact of the use of genetics and genomics in the care process as well as medical education, clinical research and ethical issues. The Precision Medicine model is expanded upon in this article to include its principles of prediction, prevention, personalization and participation. Finally, we discuss Precision Medicine in various specialty fields and how it has been implemented in developing countries and its effects on public health and medical education.

(-)-Epigallocatechin-3-gallate induces cell apoptosis in chronic myeloid leukaemia by regulating Bcr/Abl-mediated p38-MAPK/JNK and JAK2/STAT3/AKT signalling pathways

Epigallocatechin-3-gallate (EGCG), a major polyphenolic constituent of green tea, possesses remarkable chemopreventive and therapeutic potential against various types of cancer, including leukaemia. However, the molecular mechanism involved in chronic myeloid leukaemia (CML), especially imatinib-resistant CML cells, is not completely understood. In the present study, we investigated the effect of EGCG on the growth of Bcr/Abl+ CML cell lines, including imatinib-resistant cell lines and primary CML cells. The results revealed that EGCG could inhibit cell growth and induce apoptosis in CML cells. The mechanisms involved inhibition of the Bcr/Abl oncoprotein and regulation of its downstream p38-MAPK/JNK and JAK2/STAT3/AKT pathways. In conclusion, we documented the anti-CML effects of EGCG in imatinib-sensitive and imatinib-resistant Bcr/Abl+ cells, especially T315I-mutated cells.

[Protein-dysregulation in human and murine myeloproliferative neoplasms]

In this work different types of dysregulation of signaling proteins in the context of myeloproliferative neoplasms are examined. In this heterogeneous disease group, uncontrolled cell proliferation plays a crucial role for the initiation of tumorigenesis, which Robert Weinberg described as a "hallmark" for the development of cancer. Protein dysregulation in form of overexpression of GAB2, a protein involved in formation of the CML-pathognomonic BCR/ABL-translocation complex, results in an enhanced disease phenotype in a Bcr/Abl-positive mouse model and disease acceleration is associated with a change of the subcellular localization of GAB2 in human blasts in CML-bone marrow biopsies. Furthermore, analyses of a mouse model show that a protein dysregulation caused by a distinct translocation (Tel-Syk) leads to the formation of a specific and morphologically very characteristic phenotype in the bone marrow of diseased mice. Moreover, results were presented which show that in certain subgroups of Myeloproliferative Neoplasms the protein NFE2, which is initially known only as a translocating factor, is apparently regulated by altering its subcellular localization. The difference in the subcellular localization of NFE2 in erythroid bone marrow cells is so clear between Essential Thrombocythemia and Primary Myelofibrosis that quantitative NFE2 immunohistochemistry can be used as an ancillary tool to diagnostically discriminate these two entities in an early stage.

Inducible SHP-2 activation confers resistance to imatinib in drug-tolerant chronic myeloid leukemia cells

BCR-ABL kinase mutations, accounting for clinical resistance to tyrosine kinase inhibitor (TKI) such as imatinib, frequently occur in acquired resistance or in advanced phases of chronic myeloid leukemia (CML). Emerging evidence implicates a critical role for non-mutational drug resistance mechanisms underlying the survival of residual cancer 'persister' cells. Here, we utilized non-mutational imatinib-resistant K562/G cells to reveal SHP-2 as a resistance modulator of imatinib treatment response during the early phase. SHP-2 phosphorylation was significantly higher in K562/G cells than in sensitive K562 cells. In K562 cells, both short-term and long-term exposure to imatinib induced SHP-2 phosphorylation. Consistently, gain- and loss-of-function mutants in SHP-2 proved its regulation of imatinib resistance. SHP-2 inhibitor and imatinib exhibited a strong antitumor synergy in in vitro and in vivo K562/G models. Mechanistically, dual SHP-2 and BCR-ABL inhibition blocked RAF/MEK/ERK and PI3K/AKT/mTOR pathways, respectively, leading to dramatic apoptotic death of K562/G cells. In conclusion, our results highlight that SHP-2 could be exploited as a biomarker and therapeutic target during the early phase of imatinib resistance development in CML.

C-Abl is not actıvated in DNA damage-induced and Tap63-mediated oocyte apoptosıs in human ovary

There is a controversy in literature as to whether c-Abl is crucial for the induction of TAp63-mediated apoptosis and whether that inhibition of c-Abl with imatinib, which was designed to inhibit the oncogenic kinase BCR-ABL and c-kit, protects oocytes from chemotherapy-induced apoptosis in mice. No human data are available on this issue. We therefore aimed to explore whether genomic damage induced by chemotherapy drug cisplatin activates c-Abl along with TAp63 and the inhibition of c-Abl with imatinib prevents cisplatin-induced oocyte death and follicle loss in human ovary. Exposure to cisplatin induced DNA damage, activated TAp63 and SAPK/JNK pathway, and triggered apoptosis in the oocytes and granulosa cells. However, TAp63 activation after cisplatin was not associated with any increase in the expression of c-Abl. Imatinib did not prevent cisplatin-induced apoptosis of the granulosa cells or oocytes. Moreover, treatment with this drug resulted in the formation of bizarre shaped follicles lacking oocytes and increased follicular atresia by inducing apoptosis of granulosa cells and oocytes. Similar toxic effects were observed when ovarian tissue samples were incubated with a c-kit antagonist drug anti-CD117, but not with another c-Abl tyrosine kinase inhibitor GNF-2, which lacks an inhibitory action on c-kit. Intraperitoneal administration of imatinib to the xenografted animals produced similar histomorphological abnormalities in the follicles in human ovarian grafts and did not prevent cisplatin-induced follicle loss when co-administered with cisplatin. Our findings provide, for the first time, a molecular evidence for ovarian toxicity of this drug in human. Furthermore, this study together with two previous case reports of a severely compromised ovarian response to gonadotropin stimulation and premature ovarian failure in patients, while receiving imatinib, further heighten the concerns about its potential gonadotoxicity on human ovary and urge caution in its use in young female patients.

Desuppression of TGF-β signaling via nuclear c-Abl-mediated phosphorylation of TIF1γ/TRIM33 at Tyr-524, -610, and -1048

Protein-tyrosine kinases regulate a broad range of intracellular processes occurring primarily just beneath the plasma membrane. With the greatest care to prevent dephosphorylation, we have shown that nuclear tyrosine phosphorylation regulates global chromatin structural states. However, the roles for tyrosine phosphorylation in the nucleus are poorly understood. Here we identify transcriptional intermediary factor 1-γ (TIF1γ/TRIM33/Ectodermin), which suppresses transforming growth factor-β (TGF-β) signaling through the association with Smad2/3 transcription factor, as a new nuclear substrate of c-Abl tyrosine kinase. Replacement of the three tyrosine residues Tyr-524, -610, and -1048 with phenylalanine (3YF) inhibits c-Abl-mediated phosphorylation of TIF1γ and enhances TIF1γ's association with Smad3. Importantly, knockdown-rescue experiments show that 3YF strengthens TIF1γ's ability to suppress TGF-β signaling. Intriguingly, activation of c-Abl by epidermal growth factor (EGF) induces desuppression of TGF-β signaling via enhancing the tyrosine phosphorylation level of TIF1γ. TGF-β together with EGF synergistically provokes desuppressive responses of epithelial-to-mesenchymal transition through tyrosine phosphorylation of TIF1γ. These results suggest that nuclear c-Abl-mediated tyrosine phosphorylation of TIF1γ has a desuppressive role in TGF-β-Smad2/3 signaling.

Сase Report of Acute Toxic Imatinib-induced Hepatitis in a Patient with Chronic Myeloid Leukemia, Sulfa Allergy, and Rheumatoid Arthritis

The introduction of imatinib has substantially changed the approaches to the therapy of chronic myeloid leukemia. However, this drug can cause hepatic failure and death in rare cases. This report describes a clinical case of acute, toxic imatinib-induced hepatitis in a 56-year-old woman with chronic myeloid leukemia and concomitant sulfa allergy and rheumatoid arthritis. The patient developed acute imatinib-induced hepatitis after three months of treatment with imatinib and three days after increasing the imatinib dosage from 400 mg per day to 600 mg per day, resolving within three months after imatinib discontinuation and prednisolone administration. This confirms the necessity of great caution during imatinib therapy and the monitoring of liver tests. Approximately 25 reports about clinical cases of imatinib-induced hepatitis have been published up to the present.

Crosstalk between BCR-ABL and protease-activated receptor 1 (PAR1) suggests a novel target in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of the Philadelphia chromosome, which generates the oncogene BCR-ABL1. Protease-activated receptor 1 (PAR1) is involved in tumor progression and angiogenesis. We have previously reported that PAR1 expression is elevated in human leukemias that display a more aggressive clinical behavior, including the blast crisis of CML. In this study, we analyzed the crosstalk between the oncoprotein BCR-ABL and PAR1 in CML. Leukemic cell lines transfected with the BCR-ABL1 oncogene showed significantly higher expression levels of PAR1 compared with that of wild-type counterparts. This phenomenon was reversed by treatment with tyrosine kinase inhibitors (TKIs). Conversely, treatment with the PAR1 antagonist SCH79797 inhibited BCR-ABL expression. The PAR1 antagonist induced apoptosis in a dose- and time-dependent manner. Higher vascular endothelial growth factor (VEGF) levels were observed in cells transfected with BCR-ABL1 than in their wild-type counterparts. VEGF expression was strongly inhibited after treatment with either TKIs or the PAR1 antagonist. Finally, we evaluated PAR1 expression in CML patients who were either in the blast or chronic phases and had either received TKI treatment or no treatment. A significant decrease in PAR1 expression was observed in treatment-responsive patients, as opposed to a significant increase in PAR1 expression levels in treatment-resistant patients. Patients classified as high risk according to the Sokal index showed higher PAR1 expression levels. Our results demonstrate the crosstalk between BCR-ABL and PAR1. These data may offer important insight into the development of new therapeutic strategies for CML.

The Long Noncoding RNA MEG3 and its Target miR-147 Regulate JAK/STAT Pathway in Advanced Chronic Myeloid Leukemia

Background

Long non-coding (lnc) RNAs plays an important role in chronic myeloid leukemia (CML). In this study, we aimed to uncover the mechanism of the lncRNA maternally expressed 3 (MEG3) and its target microRNA-147 (miR-147) in CML.

Methods

Sixty CML patients and 10 healthy donors were included in the study. The methylation of MEG3 and miR-147 promoter was determined by methylation-specific PCR. The relationship of MEG3 and miR-147 was explored by luciferase assay. The interactions of proteins were studied by RNA pull-down assay, RNA immunoprecipitation and co-immunoprecipitation.

Findings

Patients in accelerated phase CML (CML-AP) and blast phase CML (CML-BP) showed lower expressions of MEG3 and miR-147 and higher expressions of DNMT1, DNMT3B, MBD2, MECP2 and HDAC1 compared to the controls. These patients also showed a higher degree of methylation of MEG3 and miR-147 while there was a reduction after chidamide treatment. Furthermore, the overexpression of MEG3 and miR-147 inhibited cell proliferation both in vivo and in vitro, promoted apoptosis and decreased the expressions of DNMT1, DNMT3A, DNMT3B, MBD2, HDAC1 and MECP2. We also found MEG3 interacted with DNMT1, JAK2, STAT3, HDAC1, and TYK2, and JAK2 was bound to STAT3, STAT5 and MYC. More interestingly, JAK2 was bound to TYK2 by the bridge of MEG3.

Interpretation

LncRNA MEG3 and its target miR-147 may serve as a novel therapeutic target for CML blast crisis, and chidamide might have a potential clinical application in treating CML blast crisis.

Comparison of Frequency and Sensitivity of BCR-ABL1 Kinase Domain Mutations in Asian and White Patients With Imatinib-resistant Chronic-Phase Chronic Myeloid Leukemia

INTRODUCTION

BCR-ABL1 mutations require consideration during second-line tyrosine kinase inhibitor selection for patients with chronic myeloid leukemia (CML). The present retrospective analysis compared the frequency of BCR-ABL1 mutations in Asian and white patients in whom imatinib therapy had failed.

PATIENTS AND METHODS

A nonstudy cohort (76 Asian patients from community clinical practices) and 2 study cohorts (29 Asian and 352 white patients from dasatinib phase II and III clinical trials) were identified.

RESULTS

In the nonstudy cohort, 80 mutations were identified; the most frequent was T315I (15%), followed by phosphate-binding loop mutations E255K (11%), G250E (10%), and Y253H (10%). Asian patients had a greater proportion of T315I and phosphate-binding loop mutations compared with the white patients. The nonstudy cohort was less likely to have multiple mutations compared with either study cohort. Single mutations highly resistant to dasatinib, nilotinib, and bosutinib were more frequent in the Asian than in the white cohorts.

CONCLUSION

These results suggest that mutational analysis findings will be invaluable for choosing an appropriate second-line tyrosine kinase inhibitor in Asia.

microRNA-199a/b-5p enhance imatinib efficacy via repressing WNT2 signaling-mediated protective autophagy in imatinib-resistant chronic myeloid leukemia cells

Imatinib (IM) is a first-line therapeutic drug for chronic myeloid leukemia (CML), a hematological disease. Mutations in the BCR-ABL domain increase formation of IM resistance in CML. However, not all patients are BCR-ABL domain-mutant dependent. Investigating non-mutant mechanisms in the development of acquired IM resistance is a critical issue. We explored the mechanisms which influence IM efficacy and resistance in CML. Higher protective autophagy was identified in IM-resistant K562 (K562R) cells. Inhibition of autophagy by the inhibitors, chloroquine and 3-methyladenine, enhanced IM's efficacy in K562R cells. In addition, microRNA (miR)-199a/b-5p were downregulated in K562R cells compared to parent cells. Overexpression of miR-199a/b-5p reduced autophagy and induced cell apoptosis, resulting in enhanced IM's efficacy in K562R cells. Moreover, expression levels of the Wingless-type MMTV integration site family member 2 (WNT2), a positive regulator of autophagy, were significantly higher in K562R cells, and it was validated as a direct target gene of miR-199a/b-5p. Overexpressions of miR-199a/b-5p inhibited WNT2 downstream signaling. Furthermore, overexpression and knockdown of WNT2 influenced autophagy formation and CML drug sensitivity to IM. Overexpression of WNT2 could also reverse miR-199a/b-5p-enhanced IM efficacy in K562R cells. These results emphasized that miR-199a/b-5p inhibited autophagy via repressing WNT2 signaling and might provide novel therapeutic strategies for future IM-resistant CML therapy and drug development.

Small-Molecule Screening for Genetic Diseases

The genetic determinants of many diseases, including monogenic diseases and cancers, have been identified; nevertheless, targeted therapy remains elusive for most. High-throughput screening (HTS) of small molecules, including high-content analysis (HCA), has been an important technology for the discovery of molecular tools and new therapeutics. HTS can be based on modulation of a known disease target (called reverse chemical genetics) or modulation of a disease-associated mechanism or phenotype (forward chemical genetics). Prominent target-based successes include modulators of transthyretin, used to treat transthyretin amyloidoses, and the BCR-ABL kinase inhibitor Gleevec, used to treat chronic myelogenous leukemia. Phenotypic screening successes include modulators of cystic fibrosis transmembrane conductance regulator, splicing correctors for spinal muscular atrophy, and histone deacetylase inhibitors for cancer. Synthetic lethal screening, in which chemotherapeutics are screened for efficacy against specific genetic backgrounds, is a promising approach that merges phenotype and target. In this article, we introduce HTS technology and highlight its contributions to the discovery of drugs and probes for monogenic diseases and cancer.

Long noncoding RNA MEG3 inhibits proliferation of chronic myeloid leukemia cells by sponging microRNA21

The long noncoding RNA (lnc) maternally expressed 3 (MEG3) is downregulated in many types of cancers. However, the relationship between lncRNA MEG3, microRNA-21 (miR-21) and chronic myeloid leukemia (CML) blast crisis is unknown. This study examined bone marrow samples from 40 CML patients and 10 healthy donors. Proliferation and apoptosis assays, real-time polymerase chain reaction (PCR), bisulfite sequencing PCR, Western blotting, luciferase assay, RNA pull-down, RNA immunoprecipitation (RIP), co-immunoprecipitation (CoIP) and Chromatin immunoprecipitation (ChIP) were performed. We found that MEG3 and PTEN expression were down-regulated, whereas, MDM2, DNMT1 and miR-21 were up-regulated in the accelerated and blast phases of CML. Treated with 5-azacytidine decreased the level of MDM2, DNMT1 and miR21, but increased the level of MEG3 and PTEN. Overexpression of MEG3 and silencing the expression of miR-21 inhibited proliferation and induced apoptosis. MEG3 overexpression and silencing the expression of miR21 influence the levels of MMP-2, MMP-9, bcl-2 and Bax. MEG3 was able to interact with MDM2 and EZH2. MDM2 could interact with DNMT1 and PTEN. MYC and AKT can interact with EZH2. ChIP-seq showed that the promoter of KLF4 and SFRP2 interacts with DNMT1. In conclusion, lncRNA MEG3 and its target miR21 may serve as novel therapeutic targets for CML blast crisis; and demethylation drugs might also have potential clinical application in treating CML blast crisis.

Recent Advances and Perspectives in Cancer Drug Design

Cancer is one of the leading causes of death worldwide. With the increase in life expectancy, the number of cancer cases has reached unprecedented levels. In this scenario, the pharmaceutical industry has made significant investments in this therapeutic area. Despite these efforts, cancer drug research remains a remarkably challenging field, and therapeutic innovations have not yet achieved expected clinical results. However, the physiopathology of the disease is now better understood, and the discovery of novel molecular targets has refreshed the expectations of developing improved treatments. Several noteworthy advances have been made, among which the development of targeted therapies is the most significant. Monoclonal antibodies and antibody-small molecule conjugates have emerged as a worthwhile approach to improve drug selectivity and reduce adverse effects, which are the main challenges in cancer drug discovery. This review will examine the current panorama of drug research and development (R&D) with emphasis on some of the major advances brought to clinical trials and to the market in the past five years. Breakthrough discoveries will be highlighted along with the medicinal chemistry strategies used throughout the discovery process. In addition, this review will provide perspectives and updates on the discovery of novel molecular targets as well as drugs with innovative mechanisms of action.

Big Data Approaches for Modeling Response and Resistance to Cancer Drugs

Despite significant progress in cancer research, current standard-of-care drugs fail to cure many types of cancers. Hence, there is an urgent need to identify better predictive biomarkers and treatment regimes. Conventionally, insights from hypothesis-driven studies are the primary force for cancer biology and therapeutic discoveries. Recently, the rapid growth of big data resources, catalyzed by breakthroughs in high-throughput technologies, has resulted in a paradigm shift in cancer therapeutic research. The combination of computational methods and genomics data has led to several successful clinical applications. In this review, we focus on recent advances in data-driven methods to model anticancer drug efficacy, and we present the challenges and opportunities for data science in cancer therapeutic research.

The novel piperazine-containing compound LQFM018: Necroptosis cell death mechanisms, dopamine D4 receptor binding and toxicological assessment

Piperazine is a promising scaffold for drug development due to its broad spectrum of biological activities. Based on this, the new piperazine-containing compound LQFM018 (2) [ethyl 4-((1-(4-chlorophenyl)-1H-pyrazol-4-yl)methyl)piperazine-1-carboxylate] was synthetized and some biological activities investigated. In this work, we described its ability to bind aminergic receptors, antiproliferative effects as well as the LQFM018 (2)-triggered cell death mechanisms, in K562 leukemic cells, by flow cytometric analyses. Furthermore, acute oral systemic toxicity and potential myelotoxicity assessments of LQFM018 (2) were carried out. LQFM018 (2) was originally obtained by molecular simplification from LASSBio579 (1), an analogue compound of clozapine, with 33% of global yield. Binding profile assay to aminergic receptors showed that LQFM018 (2) has affinity for the dopamine D₄ receptor (K_i = 0.26 μM). Moreover, it showed cytotoxicity in K562 cells, in a concentration and time-dependent manner; IC₅₀ values obtained were 399, 242 and 119 μM for trypan blue assay and 427, 259 and 50 μM for MTT method at 24, 48 or 72 h, respectively. This compound (427 μM) also promoted increase in LDH release and cell cycle arrest in G2/M phase. Furthermore, it triggered necrotic morphologies in K562 cells associated with intense cell membrane rupture as confirmed by Annexin V/propidium iodide double-staining. LQFM018 (2) also triggered mitochondrial disturb through loss of ΔΨm associated with increase of ROS production. No significant accumulation of cytosolic cytochrome c was verified in treated cells. Furthermore, it was verified an increase of expression of TNF-R1 and mRNA levels of CYLD with no involviment in caspase-3 and -8 activation and NF-κB in K562 cells. LQFM018 (2) showed in vitro myelotoxicity potential, but it was orally well tolerated and classified as UN GHS category 5 (LD₅₀ > 2000-5000 mg/Kg). Thus, LQFM018 (2) seems to have a non-selective action considering hematopoietic cells. In conclusion, it is suggested LQFM018 (2) promotes cell death in K562 cells via necroptotic signaling, probably with involvement of dopamine D₄ receptor. These findings open new perspectives in cancer therapy by use of necroptosis inducing agents as a strategy of reverse cancer cell chemoresistance.