Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve... more
Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve specificity. The dasatinib-l-arginine derivative (Das-R, 7) was found to be the most potent of the inhibitors tested, with IC50 values of 4.4, <0.25, and <0.45 nm against Csk, Src, and Abl kinases, respectively. The highest selectivity ratio obtained in our study, 91.4 Csk/Src, belonged to compound 18 (Das-C10 ) with an IC50 value of 3.2 μm for Csk compared with 35 nm for Src. Furthermore, many compounds displayed increased selectivity toward Src over Abl. Compounds 15 (Das-glutamic acid) and 13 (Das-cysteine) demonstrated the largest gains (10.2 and 10.3 Abl/Src IC50 ratios). Das-R (IC50 =2.06 μm) was significantly more potent than the parent dasatinib (IC50 =26.3 μm) against Panc-1 cells, whereas both compounds showed IC50 <51.2 pm against BV-...
Dasatinib (Sprycel) is a potent Breakpoint Cluster Region-Abelson (BCR-ABL) oral tyrosine kinase inhibitor which has been used in the treatment of Philadelphia-positive hematological malignancies such as Chronic Myeloid Leukemia (CML)... more
Dasatinib (Sprycel) is a potent Breakpoint Cluster Region-Abelson
(BCR-ABL) oral tyrosine kinase inhibitor which has been used in
the treatment of Philadelphia-positive hematological malignancies
such as Chronic Myeloid Leukemia (CML) and Acute Lymphoblastic
Leukemia (ALL). Herein, we describe a case in which the continuous
administration of Dasatinib led, after two months, to the transient
appearance of a clonal, Natural-Killer (NK)-like T-cell population.
This was first detected by the presence of an increased white blood
cell count consisting of lymphocytes, and review of the peripheral
smear showed large granular lymphocytes. The lymphocytosis and
the associated leukocytosis resolved within three weeks without
any interventions while the patient continued Dasatinib. This paper
will review the current literature on this subject, which suggests
that Dasatinib-associated large granular lymphocytosis (LGL) is
associated with a superior disease response.
Treatment of patients with chronic myeloid leukaemia (CML) has become increasingly difficult in recent years due to the variety of treatment options available and challenge deciding on the most appropriate treatment strategy for an... more
Treatment of patients with chronic myeloid leukaemia (CML) has become increasingly difficult in recent years due to the variety of treatment options available and challenge deciding on the most appropriate treatment strategy for an individual patient. To facilitate the treatment strategy decision, disease assessment should involve molecular response to initial treatment for an individual patient. Patients predicted not to achieve major molecular response (MMR) at 24 months to frontline imatinib may be better treated with alternative frontline therapies, such as nilotinib or dasatinib. The aims of this study were to i) understand the clinical prediction 'rules' for predicting MMR at 24 months for CML patients treated with imatinib using clinical, molecular, and cell count observations (predictive factors collected at diagnosis and categorised based on available knowledge) and ii) develop a predictive model for CML treatment management. This predictive model was developed, bas...
During the last few years many Checkpoint kinase 1/2 (Chk1/Chk2) inhibitors have been developed for the treatment of different type of cancers. In this study we evaluated the efficacy of the Chk 1/2 inhibitor prexasertib mesylate... more
During the last few years many Checkpoint kinase 1/2 (Chk1/Chk2) inhibitors have been developed for the treatment of different type of cancers. In this study we evaluated the efficacy of the Chk 1/2 inhibitor prexasertib mesylate monohydrate in B-/T- cell progenitor acute lymphoblastic leukemia (ALL) as single agent and in combination with other drugs. The prexasertib reduced the cell viability in a dose and time dependent manner in all the treated cell lines. The cytotoxic activity was confirmed by the increment of apoptotic cells (Annexin V/Propidium Iodide staining), by the increase of γH2A.X protein expression and by the activation of different apoptotic markers (Parp-1 and pro-Caspase3 cleavage). Furthermore, the inhibition of Chk1 changed the cell cycle profile. In order to evaluate the chemo-sensitizer activity of the compound, different cell lines were treated for 24 and 48 hours with prexasertib in combination with other drugs (imatinib, dasatinib and clofarabine). The resu...
Chronic myeloid leukaemia (CML) is driven by the activity of the BCR-ABL1 fusion oncoprotein. ABL1 kinase inhibitors have improved the clinical outcomes for patients with CML, with over 80% of patients treated with imatinib surviving for... more
Chronic myeloid leukaemia (CML) is driven by the activity of the BCR-ABL1 fusion oncoprotein. ABL1 kinase inhibitors have improved the clinical outcomes for patients with CML, with over 80% of patients treated with imatinib surviving for more than 10 years. Second-generation ABL1 kinase inhibitors induce more potent molecular responses in both previously untreated and imatinib-resistant patients with CML. Studies in patients with chronic-phase CML have shown that around 50% of patients who achieve and maintain undetectable BCR-ABL1 transcript levels for at least 2 years remain disease-free after the withdrawal of treatment. Here we characterize ABL001 (asciminib), a potent and selective allosteric ABL1 inhibitor that is undergoing clinical development testing in patients with CML and Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukaemia. In contrast to catalytic-site ABL1 kinase inhibitors, ABL001 binds to the myristoyl pocket of ABL1 and induces the formation of an...
Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve... more
Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve specificity. The dasatinib-l-arginine derivative (Das-R, 7) was found to be the most potent of the inhibitors tested, with IC50 values of 4.4, <0.25, and <0.45 nm against Csk, Src, and Abl kinases, respectively. The highest selectivity ratio obtained in our study, 91.4 Csk/Src, belonged to compound 18 (Das-C10 ) with an IC50 value of 3.2 μm for Csk compared with 35 nm for Src. Furthermore, many compounds displayed increased selectivity toward Src over Abl. Compounds 15 (Das-glutamic acid) and 13 (Das-cysteine) demonstrated the largest gains (10.2 and 10.3 Abl/Src IC50 ratios). Das-R (IC50 =2.06 μm) was significantly more potent than the parent dasatinib (IC50 =26.3 μm) against Panc-1 cells, whereas both compounds showed IC50 <51.2 pm against BV-...
The tyrosine kinase inhibitor dasatinib is often used after allogeneic hematopoietic cell transplantation to treat minimal residual disease in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Colitis, sometimes... more
The tyrosine kinase inhibitor dasatinib is often used after allogeneic hematopoietic cell transplantation to treat minimal residual disease in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Colitis, sometimes hemorrhagic, has occasionally been described with the use of dasatinib for both chronic myeloid leukemia and Ph+ ALL. The pathogenesis of dasatinib-induced colitis is unclear but may be related to effects of dasatinib on immune function. We describe a series of 5 patients who had 7 episodes of colitis during dasatinib use. No patient had obvious large granular lymphocytosis in peripheral blood. The histopathologic and immunohistochemical features of these cases were indistinguishable from control cases of gut graft-versus-host disease (GVHD). In all patients symptoms resolved upon discontinuation of dasatinib in addition to therapy with local or low-dose systemic steroids. An additional 3 patients who developed cytomegalovirus (CMV) colitis while on ...
Dasatinib exhibited activity in preclinical models of sarcoma. The Sarcoma Alliance for Research through Collaboration (SARC) conducted a multicenter, phase 2 trial of dasatinib in patients with advanced sarcoma. Patients received... more
Dasatinib exhibited activity in preclinical models of sarcoma. The Sarcoma Alliance for Research through Collaboration (SARC) conducted a multicenter, phase 2 trial of dasatinib in patients with advanced sarcoma. Patients received dasatinib twice daily. The primary objective was to estimate the clinical benefit rate (CBR) (complete response or partial response within 6 months or stable disease duration of ≥6 months) with a target of ≥25%. Patients were enrolled into 1 of 7 different cohorts and assessed by imaging every 8 weeks using Choi criteria tumor response and a Bayesian hierarchical design. For each subtype, enrollment was stopped after a minimum of 9 patients were treated if there was a <1% chance the CBR was ≥25%. A total of 200 patients were enrolled. Accrual was stopped early in 5 cohorts because of low CBR. The leiomyosarcoma (LMS) and undifferentiated pleomorphic sarcoma (UPS) cohorts fully accrued and 6 of 47 and 8 of 42 evaluable patients, respectively, exhibited c...
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this... more
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype.
Purpose: The second generation of tyrosine kinase inhibitors is a group of compounds that inhibit c-kit receptor activity and therefore widely used in the treatment of mastocytosis. In this research, the relationship between the mechanism... more
Purpose: The second generation of tyrosine kinase inhibitors is a group of compounds that inhibit c-kit receptor activity and therefore widely used in the treatment of mastocytosis. In this research, the relationship between the mechanism of action of tyrosine kinase inhibitors and protein kinase C is investigated in HMC-1 560 or HMC-1 560,816 cell lines. Results: From all the tyrosine kinase inhibitors tested, nilotinib is the compound that has the highest cytotoxic effect against HMC-1 560 mast cell line, while midostaurin is the most potent in HMC-1 560,816. Moreover, an increase on histamine release is observed after protein kinase C activation either in HMC-1 560 or HMC-1 560,816 cells. Furthermore, dasatinib increases histamine release in both mast cell lines, which could be related with the secondary reactions previously described in dasatinib-treated patients. Dasatinib also induces Ca 2+-dependent protein kinase C isoforms translocation from the cytosol to the membrane, whereas protein kinase Cd is translocated from the cytosol to the nucleus in the HMC-1 560,816 cell line, but not in HMC-1 560 cells. Conclusion: Results obtained demonstrate that dasatinib induces an important cytotoxic effect in both HMC-1 cell lines and differently regulates protein kinase Cd in HMC-1 560 and HMC-1 560,816 cells. Finally, our results confirm that PKCd is an essential target for dasatinib.
In principle, targeted therapies have optimal activity against a specific subset of tumors that depend upon the targeted molecule or pathway for growth, survival, or metastasis. Consequently, it is important in drug development and... more
In principle, targeted therapies have optimal activity against a specific subset of tumors that depend upon the targeted molecule or pathway for growth, survival, or metastasis. Consequently, it is important in drug development and clinical practice to have predictive biomarkers that can reliably identify patients who will benefit from a given therapy. We analyzed tumor cell-line secretomes (conditioned cell media) to look for predictive biomarkers; secretomes represent a potential source for potential biomarkers that are expressed in intracellular signaling and therefore may reflect changes induced by targeted therapy. Using Gene Ontology, we classified by function the secretome proteins of 12 tumor cell lines of different histotypes. Representations and hierarchical relationships among the functional groups differed among the cell lines. Using bioinformatics tools, we identified proteins involved in intracellular signaling pathways. For example, we found that secretome proteins related to TGF-beta signaling in thyroid cancer cells, such as vasorin, CD109, and βIG-H3 (TGFBI), were sensitive to RPI-1 and dasatinib treatments, which have been previously demonstrated to be effective in blocking cell proliferation. The secretome may be a valuable source of potential biomarkers for detecting cancer and measuring the effectiveness of cancer therapies.
Article history: Received 8 December 2015 Accepted 2 January 2016 Available online 6 January 2016 prior history of cardiovascular disease. This suggests that even patients without a prior history of overt cardiac disease are at risk of... more
Article history: Received 8 December 2015 Accepted 2 January 2016 Available online 6 January 2016 prior history of cardiovascular disease. This suggests that even patients without a prior history of overt cardiac disease are at risk of this complication and those with cardiac risk factors such as hypertension are at increased risk. Another key observation is that TKI precipitated heart failuremay be reversible in certain patients, and even after the patient has been taking
Bronchopulmonary dysplasia (BPD) is a common complication of premature birth. The histopathology of BPD is characterized by an arrest of alveolarization with fibroblast activation. The Wnt/β-catenin signaling pathway is important in early... more
Bronchopulmonary dysplasia (BPD) is a common complication of premature birth. The histopathology of BPD is characterized by an arrest of alveolarization with fibroblast activation. The Wnt/β-catenin signaling pathway is important in early lung development. When Wnt signaling is active, phosphorylation of β-catenin by tyrosine kinases at activating sites, specifically at tyrosine 489 (Y489), correlates with nuclear localization of β-catenin. We examined fetal lung tissue, lung tissue from term newborns, and lung tissue from infants who died with BPD, and found nuclear β-catenin phosphorylatation at Y489 in epithelial and mesenchymal cells in fetal tissue and BPD tissue, but not the lungs of term infants. Using a 3D human organoid model, we found increased nuclear localization of β-catenin phosphorylated at Y489 (p-β-catenin(Y489)) after exposure to alternating hypoxia and hyperoxia when compared with organoids cultured in normoxia. Exogenous stimulation of the canonical Wnt pathway i...
Myeloid leukocyte recruitment into the lung in response to environmental cues represents a key factor for the induction of lung damage. We report that Hck- and Fgr-deficient mice show a profound impairment in early recruitment of... more
Myeloid leukocyte recruitment into the lung in response to environmental cues represents a key factor for the induction of lung damage. We report that Hck- and Fgr-deficient mice show a profound impairment in early recruitment of neutrophils and monocytes in response to bacterial LPS. The reduction in interstitial and airway neutrophil recruitment was not due to a cell-intrinsic migratory defect, because Hck- and Fgr-deficient neutrophils were attracted to the airways by the chemokine CXCL2 as wild type cells. However, early accumulation of chemokines and TNF-α in the airways was reduced in hck(-/-)fgr(-/-) mice. Considering that chemokine and TNF-α release into the airways was neutrophil independent, as suggested by a comparison between control and neutrophil-depleted mice, we examined LPS-induced chemokine secretion by neutrophils and macrophages in wild type and mutant cells. Notably, mutant neutrophils displayed a marked deficit in their capability to release the chemokines CXCL...
To the authors' knowledge, the optimal frequency of monitoring after tyrosine kinase inhibitor (TKI) discontinuation in patients with chronic myeloid leukemia (CML) has not been established. Data regarding the discontinuation of... more
To the authors' knowledge, the optimal frequency of monitoring after tyrosine kinase inhibitor (TKI) discontinuation in patients with chronic myeloid leukemia (CML) has not been established. Data regarding the discontinuation of second-generation TKIs used in first-line treatment or after the failure of first-line treatment with TKIs are limited. Herein, the authors report real-world experience with "reduced frequency" molecular monitoring in patients with CML in all phases who discontinued treatment with imatinib, dasatinib, or bosutinib. The records of patients who discontinued TKIs were reviewed. Patients who discontinued TKIs were monitored prospectively on an intended schedule of monthly blood quantitative reverse transcriptase-polymerase chain reaction for BCR-ABL1 for 3 months, quarterly for 12 months, and every 6 months thereafter until loss of major molecular response (MMR). After loss of MMR, the TKI that previously was discontinued was reinitiated. Between J...
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this... more
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype.
Up to now, several clinical studies have been started investigating the relevance of receptor tyrosine kinase (RTK) inhibitors upon progression free survival in various pediatric brain tumors. However, single targeted kinase inhibition... more
Up to now, several clinical studies have been started investigating the relevance of receptor tyrosine kinase (RTK) inhibitors upon progression free survival in various pediatric brain tumors. However, single targeted kinase inhibition failed, possibly due to tumor resistance mechanisms. The present study will extend our previous observations that vascular endothelial growth factor receptor (VEGFR)-2, platelet derived growth factor receptor (PDGFR)β, Src, the epidermal growth factor receptor (ErbB) family, and hepatocyte growth factor receptor (HGFR/cMet) are potentially drugable targets in pediatric low grade astrocytoma and ependymoma with investigations concerning growth-factor-driven rescue. This was investigated in pediatric low grade astrocytoma and ependymoma cell lines treated with receptor tyrosine kinase (RTK) inhibitors e.g. sorafenib, dasatinib, canertinib and crizotinib. Flow cytometry analyses showed high percentage of cells expressing VEGFR-1, fibroblast growth factor...
Resistance to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, often related to Ras or secondary EGFR mutations, is a relevant clinical issue in Non-Small Cell Lung Cancer (NSCLC). Although Src TK has been involved in... more
Resistance to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, often related to Ras or secondary EGFR mutations, is a relevant clinical issue in Non-Small Cell Lung Cancer (NSCLC). Although Src TK has been involved in such resistance, clinical development of its inhibitors has been so far limited.To better define the molecular targets of the Src TKIs saracatinib, dasatinib and bosutinib, we used a variety of in vitro/in vivo studies.Kinase assays supported by docking analysis demonstrated that all the compounds directly inhibit EGFR TK variants. However, in live cells only saracatinib efficiently reduced EGFR activation, while dasatinib was the most effective agent in inhibiting Src TK. Consistently, a pronounced anti-proliferative effect was achieved with saracatinib, in EGFR mutant cells, or with dasatinib, in wt EGFR/Ras mutant cells, poorly dependent on EGFR and erlotinib-resistant. We then identified the most effective drug combinations to overcome resistance...
Triple-negative breast cancer (TNBC) accounts for approximately 15-20% of all breast cancer (BC) cases and contributes disproportionately to BC mortality. TAZ, a key transducer of the Hippo pathway, has recently been demonstrated to... more
Triple-negative breast cancer (TNBC) accounts for approximately 15-20% of all breast cancer (BC) cases and contributes disproportionately to BC mortality. TAZ, a key transducer of the Hippo pathway, has recently been demonstrated to confer breast cancer stem cell (CSC) traits. However, TAZ target genes and the underlying transcriptional regulatory pathways responsible for the CSC phenomenon remain unknown. Here, we demonstrate that the oncogenic activity of TAZ is essential for propagation of the malignant phenotype. We further show that constitutively active TAZ tumor-derived cells exhibit unique tumor-initiating properties, including increased self-renewal and metastatic seeding potential, acquired chemotherapy resistance and the ability to efficiently regenerate tumor formation in vivo. Combined digital RNA expression analysis and computational network approaches identify several signaling pathways that distinguish breast cancer tumor-initiating cells (T-ICs) from bulk tumor cell...
Intratumoral heterogeneity of signaling networks may contribute to targeted cancer therapy resistance, including in the highly lethal brain cancer glioblastoma (GBM). We performed single-cell phosphoproteomics on a patient-derived in vivo... more
Intratumoral heterogeneity of signaling networks may contribute to targeted cancer therapy resistance, including in the highly lethal brain cancer glioblastoma (GBM). We performed single-cell phosphoproteomics on a patient-derived in vivo GBM model of mTOR kinase inhibitor resistance and coupled it to an analytical approach for detecting changes in signaling coordination. Alterations in the protein signaling coordination were resolved as early as 2.5 days after treatment, anticipating drug resistance long before it was clinically manifest. Combination therapies were identified that resulted in complete and sustained tumor suppression in vivo. This approach may identify actionable alterations in signal coordination that underlie adaptive resistance, which can be suppressed through combination drug therapy, including non-obvious drug combinations.
Newer tyrosine kinase inhibitors (TKIs) (bosutinib, ponatinib) and allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be utilized as a salvage therapy in patients with chronic myeloid leukemia (CML) who failed two lines... more
Newer tyrosine kinase inhibitors (TKIs) (bosutinib, ponatinib) and allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be utilized as a salvage therapy in patients with chronic myeloid leukemia (CML) who failed two lines (imatinib → nilotinib or imatinib → dasatinib) of TKI therapy. However, these TKIs are not available in many countries and not all patients can undergo allo-HSCT. In this study, CML patients who received dasatinib or nilotinib as a third-line treatment were retrospectively evaluated. Out of 209 patients, third-line dasatinib/nilotinib was administered in 21. During the follow-up, 16 out of 21 patients gained and/or maintained an optimal response, and 4 patients died due to progression. Seventeen patients were alive at the time of the analysis, of which 13 were still on TKI, whereas 4 patients quit treatment. In patients failing two lines of TKI, dasatinib or nilotinib can be beneficial and safely administered as a third-line treatment especially in na...
The skin is a squamous epithelium that is continuously renewed by a population of basal layer stem/progenitor cells and can heal wounds. Here we show that YAP and TAZ are nuclear localised in the basal layer of skin and are elevated upon... more
The skin is a squamous epithelium that is continuously renewed by a population of basal layer stem/progenitor cells and can heal wounds. Here we show that YAP and TAZ are nuclear localised in the basal layer of skin and are elevated upon wound healing. Skin-specific deletion of both YAP and TAZ in adult mice slows proliferation of basal layer cells, leads to hair loss and impairs regeneration after wounding. Contact with the basal extracellular matrix and consequent Integrin-Src signalling is a key determinant of YAP/TAZ nuclear localisation in basal layer cells and in skin tumours. Contact with the basement membrane is lost in differentiating daughter cells, where YAP and TAZ become mostly cytoplasmic. In other types of squamous epithelia and squamous cell carcinomas, a similar control mechanism is present. In contrast, columnar epithelia differentiate an apical domain that recruits CRB3, MERLIN, KIBRA and SAV to induce Hippo signalling and retain YAP/TAZ in the cytoplasm despite c...
Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve... more
Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve specificity. The dasatinib-l-arginine derivative (Das-R, 7) was found to be the most potent of the inhibitors tested, with IC50 values of 4.4, <0.25, and <0.45 nm against Csk, Src, and Abl kinases, respectively. The highest selectivity ratio obtained in our study, 91.4 Csk/Src, belonged to compound 18 (Das-C10 ) with an IC50 value of 3.2 μm for Csk compared with 35 nm for Src. Furthermore, many compounds displayed increased selectivity toward Src over Abl. Compounds 15 (Das-glutamic acid) and 13 (Das-cysteine) demonstrated the largest gains (10.2 and 10.3 Abl/Src IC50 ratios). Das-R (IC50 =2.06 μm) was significantly more potent than the parent dasatinib (IC50 =26.3 μm) against Panc-1 cells, whereas both compounds showed IC50 <51.2 pm against BV-...
Dasatinib exhibited activity in preclinical models of sarcoma. The Sarcoma Alliance for Research through Collaboration (SARC) conducted a multicenter, phase 2 trial of dasatinib in patients with advanced sarcoma. Patients received... more
Dasatinib exhibited activity in preclinical models of sarcoma. The Sarcoma Alliance for Research through Collaboration (SARC) conducted a multicenter, phase 2 trial of dasatinib in patients with advanced sarcoma. Patients received dasatinib twice daily. The primary objective was to estimate the clinical benefit rate (CBR) (complete response or partial response within 6 months or stable disease duration of ≥6 months) with a target of ≥25%. Patients were enrolled into 1 of 7 different cohorts and assessed by imaging every 8 weeks using Choi criteria tumor response and a Bayesian hierarchical design. For each subtype, enrollment was stopped after a minimum of 9 patients were treated if there was a <1% chance the CBR was ≥25%. A total of 200 patients were enrolled. Accrual was stopped early in 5 cohorts because of low CBR. The leiomyosarcoma (LMS) and undifferentiated pleomorphic sarcoma (UPS) cohorts fully accrued and 6 of 47 and 8 of 42 evaluable patients, respectively, exhibited c...
Dasatinib is a multi-kinase inhibitor in clinical trials for glioma, and thus far failed to demonstrate significant efficacy. We investigated whether the ABC efflux transporters, ABCG2 and ABCB1, expressed in the blood-brain barrier... more
Dasatinib is a multi-kinase inhibitor in clinical trials for glioma, and thus far failed to demonstrate significant efficacy. We investigated whether the ABC efflux transporters, ABCG2 and ABCB1, expressed in the blood-brain barrier (BBB), are limiting the efficacy of dasatinib in the treatment of glioma using genetic and pharmacological approaches. We utilized a genetic brainstem glioma mouse model driven by platelet-derived growth factor-B and p53 loss using abcg2/abcb1 wild type (ABC WT) or abcg2/abcb1 knockout mice (ABC KO). First, we observed that brainstem glioma tumor latency is significantly prolonged in ABC KO versus ABC WT mice (median survival of 47 vs. 34 days). Dasatinib treatment nearly doubles the survival of brainstem glioma-bearing ABC KO mice (44 vs. 80 days). Elacridar, an ABCG2 and ABCB1 inhibitor, significantly increases the efficacy of dasatinib in brainstem glioma-bearing ABC WT mice (42 vs. 59 days). Pharmacokinetic analysis demonstrates that dasatinib delive...
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. Despite the advances in surgery, radiotherapy and chemotherapy, patient survival averages only 14.6 months. In most GBM tumors, tyrosine kinases show... more
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. Despite the advances in surgery, radiotherapy and chemotherapy, patient survival averages only 14.6 months. In most GBM tumors, tyrosine kinases show increased activity and/or expression and actively contribute to the development, recurrence and onset of treatment resistance; making their inhibition an appealing therapeutic strategy. We compared the cytotoxicity of 12 tyrosine kinase inhibitors in vitro. A combination of crizotinib and dasatinib emerged as the most cytotoxic across established and primary human GBM cell lines. The combination treatment induced apoptotic cell death and polyploidy. Furthermore, the combination treatment led to the altered expression and localization of several tyrosine kinase receptors such as Met and EGFR and downstream effectors as such as SRC. Furthermore, the combination treatment reduced the migration and invasion of GBM cells and prevented endothelial cell tube ...
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this... more
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype.
Purpose: The second generation of tyrosine kinase inhibitors is a group of compounds that inhibit c-kit receptor activity and therefore widely used in the treatment of mastocytosis. In this research, the relationship between the mechanism... more
Purpose: The second generation of tyrosine kinase inhibitors is a group of compounds that inhibit c-kit receptor activity and therefore widely used in the treatment of mastocytosis. In this research, the relationship between the mechanism of action of tyrosine kinase inhibitors and protein kinase C is investigated in HMC-1 560 or HMC-1 560,816 cell lines. Results: From all the tyrosine kinase inhibitors tested, nilotinib is the compound that has the highest cytotoxic effect against HMC-1 560 mast cell line, while midostaurin is the most potent in HMC-1 560,816. Moreover, an increase on histamine release is observed after protein kinase C activation either in HMC-1 560 or HMC-1 560,816 cells. Furthermore, dasatinib increases histamine release in both mast cell lines, which could be related with the secondary reactions previously described in dasatinib-treated patients. Dasatinib also induces Ca 2+-dependent protein kinase C isoforms translocation from the cytosol to the membrane, whereas protein kinase Cd is translocated from the cytosol to the nucleus in the HMC-1 560,816 cell line, but not in HMC-1 560 cells. Conclusion: Results obtained demonstrate that dasatinib induces an important cytotoxic effect in both HMC-1 cell lines and differently regulates protein kinase Cd in HMC-1 560 and HMC-1 560,816 cells. Finally, our results confirm that PKCd is an essential target for dasatinib.
Chronic use of tyrosine kinase inhibitors (TKIs) may lead to previously unrecognized adverse events. This study evaluated the incidence of acute kidney injury (AKI) and chronic kidney disease (CKD) in chronic-phase (CP) chronic myeloid... more
Chronic use of tyrosine kinase inhibitors (TKIs) may lead to previously unrecognized adverse events. This study evaluated the incidence of acute kidney injury (AKI) and chronic kidney disease (CKD) in chronic-phase (CP) chronic myeloid leukemia (CML) patients treated with imatinib, dasatinib, and nilotinib. Four hundred sixty-eight newly diagnosed CP CML patients treated with TKIs were analyzed. The molecular and cytogenetic response data, creatinine, and glomerular filtration rate (GFR) were followed from the start of therapy to the last follow-up (median, 52 months). GFR was estimated with the Modification of Diet in Renal Disease equation. Nineteen patients (4%) had TKI-associated AKI. Imatinib was associated with a higher incidence of AKI in comparison with dasatinib and nilotinib (P = .014). Fifty-eight patients (14%) developed CKD while they were receiving a TKI; 49 of these patients (84%) did so while they were being treated with imatinib (P < .001). Besides imatinib, age,...