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Drug combination therapy is a highly effective approach for enhancing the therapeutic efficacy of anti-cancer drugs and overcoming drug resistance. However, the innumerable possible drug combinations make it impractical to screen all synergistic drug pairs. Moreover, biological insights into synergistic drug pairs are still lacking. To address this challenge, we systematically analyzed drug combination datasets curated from multiple databases to identify drug pairs more likely to show synergy. We classified drug pairs based on their MoA and discovered that 110 MoA pairs were significantly enriched in synergy in at least one type of cancer. To improve the accuracy of predicting synergistic effects of drug pairs, we developed a suite of machine learning models that achieve better predictive performance. Unlike most previous methods that were rarely validated by wet-lab experiments, our models were validated using two-dimensional cell lines and three-dimensional tumor slice culture (3D-TSC) models, implying their practical utility. Our prediction and validation results indicated that the combination of the RTK inhibitors Lapatinib and Pazopanib exhibited a strong therapeutic effect in breast cancer by blocking the downstream PI3K/AKT/mTOR signaling pathway. Furthermore, we incorporated molecular features to identify potential biomarkers for synergistic drug pairs, and almost all potential biomarkers found connections between drug targets and corresponding molecular features using protein-protein interaction network. Overall, this study provides valuable insights to complement and guide rational efforts to develop drug combination treatments.
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Antineoplásicos , Neoplasias da Mama , Humanos , Feminino , Fosfatidilinositol 3-Quinases , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Transdução de Sinais , Neoplasias da Mama/tratamento farmacológico , Sistemas de Liberação de MedicamentosRESUMO
Purpose Combining small-molecule inhibitors of different targets was shown to be synergistic in preclinical studies. Testing this concept in clinical trials is, however, daunting due to challenges in toxicity management and efficacy assessment. This study attempted to evaluate the safety and efficacy of vatalanib plus everolimus in patients with advanced solid tumors and explore the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) studies as a predictive biomarker. Patients and Methods This single-center, phase I trial containing 70 evaluable patients consisted of a dose escalation proportion based on the traditional "3 + 3" design (cohort IA and IB) and a dose expansion proportion (cohort IIA and IIB). Toxicity was evaluated using the Common Terminology Criteria of Adverse Events. Antitumor activity was assessed using the Modified Response Evaluation Criteria in Solid Tumors. Results The maximum tolerated doses were determined to be vatalanib 1250 mg once daily or 750 mg twice daily in combination with everolimus 10 mg once daily. No treatment-related death occurred. The most common toxicities were hypertriglyceridemia, hypercholesterolemia, fatigue, vomiting, nausea and diarrhea. There was no complete response. Nine patients (12.9%) had partial response (PR) and 41 (58.6%) had stable disease (SD). Significant antitumor activity was observed in neuroendocrine tumors with a disease-control rate (PR + SD) of 66.7% and other tumor types including renal cancer, melanoma, and non-small-cell lung cancer. Conclusions The combination of vatalanib and everolimus demonstrated reasonable toxicity and clinical activity. Future studies combining targeted therapies and incorporating biomarker analysis are warranted based on this phase I trial.
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Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Everolimo/administração & dosagem , Neoplasias/tratamento farmacológico , Ftalazinas/administração & dosagem , Inibidores de Proteínas Quinases/administração & dosagem , Piridinas/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Serina-Treonina Quinases TOR/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Everolimo/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ftalazinas/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Piridinas/efeitos adversos , Resultado do Tratamento , Adulto JovemRESUMO
Introduction Vatalanib is an oral receptor tyrosine kinase inhibitor that blocks all known VEGF, PDGF, and c-Kit receptors. This phase I study evaluated the safety, tolerability, and biologic activity of the combination of vatalanib with pemetrexed disodium in patients with advanced solid tumors. Methods Patients were administered escalating twice daily doses of vatalanib in combination with pemetrexed disodium in 21-day cycles. A dose expansion cohort was enrolled to further define the maximum tolerated dose (MTD) and further evaluate efficacy. Results A total of 29 patients were enrolled in the study (dose escalation, 9; dose expansion, 20). Dose-limiting toxicities included grade 4 thrombocytopenia (6.9%) and febrile neutropenia, anorexia, constipation, and dehydration. Other common adverse events were fatigue (75%), nausea (66%), vomiting (48%), oral mucositis (31%) and diarrhea (28%). The majority of these toxicities were Grade 1-2. The MTD was reached at vatalanib 250 mg twice daily continuously combined with pemetrexed disodium 500 mg/m2 day 1. Overall, 2 patients (6.9%) had partial responses, 8 (27.6%) had stable disease for at least 4 cycles, 5 had progressive disease (17.2%) and 5 went off study before disease assessment. Conclusion The combination of vatalanib with pemetrexed disodium was feasible, but not well tolerated. The modest efficacy results are consistent with other results obtained from combinations of chemotherapy and a large number of VEGF tyrosine kinase inhibitors. This combination should not be developed further unless predictive biomarkers can be identified.
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Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias/tratamento farmacológico , Pemetrexede/administração & dosagem , Ftalazinas/administração & dosagem , Inibidores de Proteínas Quinases/administração & dosagem , Piridinas/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Pemetrexede/efeitos adversos , Ftalazinas/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Piridinas/efeitos adversos , Distribuição Aleatória , Resultado do TratamentoRESUMO
The clinical efficacy of anti-angiogenic monotherapies in metastatic breast cancer is less than originally anticipated, and it is not clear what the response of bone metastasis to anti-angiogenic therapies is. Here, we examined the impact of neutralizing tumor-derived vascular endothelial growth factor (VEGF) in animal models of subcutaneous tumor growth and bone metastasis formation. Silencing of VEGF expression (Sh-VEGF) in osteotropic human MDA-MB-231/B02 breast cancer cells led to a substantial growth inhibition of subcutaneous Sh-VEGF B02 tumor xenografts, as a result of reduced angiogenesis, when compared to that observed with animals bearing mock-transfected (Sc-VEGF) B02 tumors. However, there was scant evidence that either the silencing of tumor-derived VEGF or the use of a VEGF-neutralizing antibody (bevacizumab) affected B02 breast cancer bone metastasis progression in animals. We also examined the effect of vatalanib (a VEGF receptor tyrosine kinase inhibitor) in this mouse model of bone metastasis. However, vatalanib failed to inhibit bone metastasis caused by B02 breast cancer cells. In sharp contrast, vatalanib in combination with bevacizumab reduced not only bone destruction but also skeletal tumor growth in animals bearing breast cancer bone metastases, when compared with either agent alone. Thus, our study highlights the importance of targeting both the tumor compartment and the host tissue (i.e., skeleton) to efficiently block the development of bone metastasis. We believe this is a crucially important observation as the clinical benefit of anti-angiogenic monotherapies in metastatic breast cancer is relatively modest.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Ósseas/secundário , Neoplasias Ósseas/terapia , Neoplasias da Mama/terapia , Inibidores da Angiogênese/administração & dosagem , Animais , Anticorpos Monoclonais Humanizados/administração & dosagem , Bevacizumab , Neoplasias Ósseas/irrigação sanguínea , Neoplasias Ósseas/genética , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Hospedeiro Imunocomprometido , Camundongos , Camundongos Endogâmicos C3H , Osteólise/tratamento farmacológico , Osteólise/patologia , Ftalazinas/administração & dosagem , Gravidez , Piridinas/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Transfecção , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
AIMS: Vatalanib is an oral anti-angiogenesis agent that inhibits vascular endothelial growth factor receptor tyrosine kinases, which in patients showed auto induction of metabolism and variability in pharmacokinetic (PK) disposition. The objective was to characterize the population PK and time-dependent change in vatalanib clearance and assess exposure-toxicity relationship in patients with myelodysplastic syndrome (MDS). METHODS: This was an open-label phase II study of vatalanib in MDS patients receiving 750-1250 mg once daily in 28-day cycles. Serial blood samples were obtained and plasma vatalanib concentrations measured by HPLC. Population PK analysis was performed using nonmem 7.2 with FO estimation since FOCE failed. The final model was evaluated using goodness-of-fit plots, bootstrap analysis, and visual predictive check. RESULTS: Pharmacokinetic data were complete for 137 patients (86 M, 51 F), of median age 70 years (range 20-91). A one-compartment model with lagged first-order absorption and time-dependent change in oral clearance was fitted to the vatalanib plasma concentration versus time data. The population means for pre-induction and post-induction oral clearance were 24.1 l h(-1) (range: 9.6-45.5) and 54.9 l h(-1) (range: 39.8-75.6), respectively. The apparent oral clearance increased 2.3-fold, (range: 1.7-4.1-fold) from first dose to steady state. Our data did not identify a significant relationship of the predefined covariates with vatalanib pharmacokinetics, although power to detect such a relationship was limited. CONCLUSIONS: Vatalanib pharmacokinetics were highly variable and the extent of auto induction was not determined to correlate with any of the pre-defined covariates.
Assuntos
Inibidores da Angiogênese/farmacocinética , Síndromes Mielodisplásicas/tratamento farmacológico , Ftalazinas/farmacocinética , Piridinas/farmacocinética , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/uso terapêutico , Área Sob a Curva , Simulação por Computador , Interpretação Estatística de Dados , Feminino , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Modelos Biológicos , Síndromes Mielodisplásicas/metabolismo , Ftalazinas/administração & dosagem , Ftalazinas/efeitos adversos , Ftalazinas/uso terapêutico , Estudos Prospectivos , Piridinas/administração & dosagem , Piridinas/efeitos adversos , Piridinas/uso terapêutico , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fatores de Tempo , Adulto JovemRESUMO
Glioblastoma multiforme (GBM) is known as the primary malignant and most devastating form of tumor found in the central nervous system of the adult population. The active pharmaceutical component in current chemotherapy regimens is mostly hydrophobic and poorly water-soluble, which hampers clinical implications. Nanodrug formulations using nanocarriers loaded with such drugs assisted in water dispersibility, improved cellular permeability, and drug efficacy at a low dose, thus adding to the overall practical value. Here, we successfully developed a water-dispersible and biocompatible nanocargo (GO-PEG) based on covalently modified graphene oxide (GO) with a 6-armed poly(ethylene glycol) amine dendrimer for effective loading of the two hydrophobic anticancer drug molecules, CPI444 and vatalanib. These drug molecules target adenosine receptor (A2AR), vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and type III stem cell receptor tyrosine kinase (c-KIT), which plays a crucial role in cancers. The effective cellular delivery of the drugs when loaded on GO-PEG is attributed to the increased permeability of the drug-nanoconjugate formulation. We observed that this combinatorial drug treatment with nanocargo resulted in a significant reduction in the overall cell survival as supported by reduced calcium levels and stem cell markers such as Oct4 and Nanog, which are two of the prime factors for GBM stem cell proliferation. Furthermore, reduced expression of CD24 upon treatment with nanoformulation impeded cellular migration. Cellular assays confirmed inhibition of cell proliferation, migration, and angiogenic potential of GBM treated with GO-PEG-Drug conjugates. Ultimately, GBM U87 cells assumed programmed cell death at a very low concentration due to nanocarrier-mediated drug delivery along with the chosen combination of drugs. Together, this study demonstrated the advantage of GO-PEG mediated combined delivery of CPI444 and vatalanib drugs with increased permeability, a three-pronged combinatorial strategy toward effective GBM treatment.
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Angiogenesis is a fundamental developmental process and a hallmark of cancer progression. Receptor tyrosine kinases (RTK) are targets for cancer therapy which may include their action as anti-angiogenic agents. Derazantinib (DZB) is an inhibitor of the fibroblast growth factor receptors (FGFRs) 1-3 as well as other kinase targets including vascular endothelial growth factor receptor 2 (VEGFR2), colony stimulating factor-1 receptor (CSF1R) and platelet-derived growth factor beta receptor (PDGFRbeta). This study aimed to investigate the effect of DZB on blood vessel morphogenesis and to compare its activity to known specific FGFR and VEGFR inhibitors. For this purpose, we used the developing vasculature in the zebrafish embryo as a model system for angiogenesis in vivo. We show that DZB interferes with multiple angiogenic processes that are linked to FGF and VEGF signalling, revealing a potential dual role for DZB as a potent anti-angiogenic treatment.
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Alzheimer's disease (AD) is a highly prevalent neurodegenerative disease characterized by Aß accumulation and tau hyperphosphorylation. Epidemiological evidence for a negative correlation between cancer and AD has led to the proposed use of tyrosine kinase inhibitors (TKIs) such as dasatinib and masitinib for AD, with reported beneficial effects in the AD brain. The TKI vatalanib inhibits angiogenesis by inhibiting vascular endothelial growth factor receptor (VEGFR). Although changes in VEGF and VEGFR have been documented in AD, the effect of vatalanib on AD pathology has not been investigated. In this study, the effects of vatalanib on tau phosphorylation and Aß accumulation in 5xFAD mice, a model of AD, were evaluated by immunohistochemistry. Vatalanib administration significantly reduced tau phosphorylation at AT8 and AT100 by increasing p-GSK-3ß (Ser9) in 5xFAD mice. In addition, vatalanib reduced the number and area of Aß plaques in the cortex in 5xFAD mice. Our results suggest that vatalanib has potential as a regulator of AD pathology.
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Doença de Alzheimer/patologia , Ftalazinas/farmacologia , Piridinas/farmacologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Humanos , Masculino , Camundongos Transgênicos , Fosforilação/efeitos dos fármacos , Ftalazinas/química , Piridinas/química , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteínas tau/metabolismoRESUMO
Although VEGF (vascular endothelial growth factor) inhibitors (VEGFIs), are effective anticancer therapies, they cause hypertension through unknown mechanisms. We questioned whether changes in vascular redox state may be important, because VEGF signaling involves nitric oxide (NO) and reactive oxygen species. Molecular mechanisms, including NOS, NADPH oxidase (Nox)-derived reactive oxygen species, antioxidant systems, and vasoconstrictor signaling pathways, were probed in human endothelial cells and vascular smooth muscle exposed to vatalanib, a VEGFI. Vascular functional effects of VEGFI were assessed ex vivo in mouse arteries. Cardiovascular and renal in vivo effects were studied in vatalanib- or gefitinib (EGFI [epidermal growth factor inhibitor])-treated mice. In endothelial cells, vatalanib decreased eNOS (Ser1177) phosphorylation and reduced NO and H2O2 production, responses associated with increased Nox-derived O2- and ONOO- formation. Inhibition of Nox1/4 (GKT137831) or Nox1 (NoxA1ds), prevented vatalanib-induced effects. Nrf-2 (nuclear factor erythroid 2-related factor 2) nuclear translocation and expression of Nrf-2-regulated antioxidant enzymes were variably downregulated by vatalanib. In human vascular smooth muscles, VEGFI increased Nox activity and stimulated Ca2+ influx and MLC20 phosphorylation. Acetylcholine-induced vasodilatation was impaired and U46619-induced vasoconstriction was enhanced by vatalanib, effects normalized by N-acetyl-cysteine and worsened by L-NAME. In vatalanib-, but not gefitinib-treated mice vasorelaxation was reduced and media:lumen ratio of mesenteric arteries was increased with associated increased cardiovascular and renal oxidative stress, decreased Nrf-2 activity and downregulation of antioxidant genes. We demonstrate that inhibition of VEGF signaling induces vascular dysfunction through redox-sensitive processes. Our findings identify Noxs and antioxidant enzymes as novel targets underling VEGFI-induced vascular dysfunction. These molecular processes may contribute to vascular toxicity and hypertension in VEGFI-treated patients.
Assuntos
Endotélio Vascular/metabolismo , Gefitinibe/farmacologia , Oxirredução/efeitos dos fármacos , Ftalazinas/farmacologia , Piridinas/farmacologia , Fatores de Crescimento do Endotélio Vascular , Vasoconstrição , Vasodilatação , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Animais , Antioxidantes/metabolismo , Humanos , Camundongos , NADPH Oxidases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fatores de Crescimento do Endotélio Vascular/metabolismo , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologiaRESUMO
BACKGROUND: Extensive studies were reported in the synthesis of several phthalazine derivatives as promising anticancer agents as potent VEGFR-2 inhibitors. Vatalanib (PTK787) was the first anilinophthalazine published derivative as a potent inhibitor of VEGFR. The discovery of vatalanib as a clinical candidate led to the design and synthesis of different anilinophthalazine derivatives as potent inhibitors for VEGFR-2. The objective of present research work is the synthesis of new agents with the same essential pharmacophoric features of the reported and clinically used VEGFR-2 inhibitors (e.g vatalanib and sorafenib). The main core of our molecular design rationale comprised bioisosteric modification strategies of VEGFR-2 inhibitors at four different positions. MATERIAL AND METHODS: A correlation between structure and biological activity of our designed phthalazines was established using molecular docking and VEGFR-2 kinase assay. RESULTS AND DISCUSSION: In view of their expected anticancer activity, novel triazolo[3,4-a]phthalazine derivatives 5-6a-o and 3-substituted-bis([1,2,4]triazolo)[3,4-a:4',3'-c]phthalazines 9a-b were designed, synthesized and evaluated for their anti-proliferative activity against two human tumor cell lines HCT-116 human colon adenocarcinoma and MCF-7 breast cancer. It was found that, compound 6o the most potent derivative against both HCT116 and MCF-7 cancer cell lines. Compounds 6o, 6m, 6d and 9b showed the highest anticancer activities against HCT116 human colon adenocarcinoma with IC50 of 7±0.06, 13±0.11, 15±0.14 and 23±0.22 µM respectively while compounds 6o, 6d, 6a and 6n showed the highest anticancer activities against MCF-7 breast cancer with IC50 of 16.98±0.15, 18.2±0.17, 57.54±0.53 and 66.45±0.67 µM respectively. Sorafenib as a highly potent VEGFR-2 inhibitor was used as a reference drug with IC50 of 5.47±0.3 and 7.26±0.3 µM respectively. Nine compounds were further evaluated for their VEGFR-2 inhibitory activity. Compounds 6o, 6m, 6d and 9b emerged as the most active counterparts against VEGFR-2 with IC50 values of 0.1±0.01, 0.15±0.02, 0.28±0.03 and 0.38±0.04 µM, respectively comparable to that of sorafenib (IC50 = 0.1±0.02) µM. Furthermore, molecular docking studies were carried out for all synthesized compounds to investigate their binding pattern and predict their binding affinities towards VEGFR-2 active site. In silico ADMET studies were calculated for the tested compounds. Most of our designed compounds exhibited good ADMET profile. CONCLUSION: The obtained results showed that, the most active compounds could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective VEGFR-2 inhibitors with higher anticancer analogs.
Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Simulação de Acoplamento Molecular , Ftalazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Triazóis/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Células MCF-7 , Estrutura Molecular , Ftalazinas/síntese química , Ftalazinas/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
We have recently reported that vatalanib, an orally active small molecule multi-tyrosine kinase inhibitor (Hess-Stumpp et al., 2005 [1]), can sensitize multidrug resistant (MDR) colon cancer cells to chemotherapy under hypoxia by inhibiting two MDR transporters ABCB1 and ABCG2 (To et al., 2015 [2]). This data article describes the possible circumvention of resistance to specifically platinum (Pt)-based anticancer drugs by vatalanib via inhibition of two other efflux transporters ABCC2 and ATP7A. Data from the flow cytometric transporter efflux assay showed specific inhibition of ABCC2 activity by vatalanib in stable transfected cells and ABCC2-overexpressing oxaliplatin-resistant colon cancer cells HCT116/Oxa. We also performed the transporter ABCC2 ATPase assay and showed an increase in ATP hydrolysis by ABCC2 in the presence of vatalanib. ATP7A mRNA expression was also shown to be upregulated in HCT116/Oxa cells. Vatalanib was shown to suppress this upregulated ATP7A expression. Data from the cellular Pt accumulation assay showed a lower Pt accumulation in HCT116/Oxa cells than the parental sensitive HCT116 cells. Vatalanib was shown to increase cellular Pt accumulation in a concentration-dependent manner. Combination of oxaliplatin and vatalanib was shown to restore the suppressed apoptosis in HCT116/Oxa cells.
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Cancer microenvironment is characterized by significantly lower oxygen concentration. This hypoxic condition is known to reduce drug responsiveness to cancer chemotherapy via multiple mechanisms, among which the upregulation of the ATP-binding cassette (ABC) efflux transporters confers resistance to a wide variety of structurally unrelated anticancer drugs. Vatalanib (PTK787/ZK22584) is a multitargeted tyrosine kinase inhibitor for all isoforms of VEGFR, PDGFR and c-Kit, which exhibit potent anticancer activity in vitro and in vivo. We investigated the potentiation effect of vatalanib on the anticancer activity of conventional cytotoxic drugs in colon cancer cell lines under both normoxic and hypoxic conditions. Mechanistically, vatalanib was found to inhibit ABCG2 and ABCB1 efflux activity, presumably by acting as a competitive inhibitor and interfering with their ATPase activity. Under hypoxic growth condition, ABCG2 and ABCB1-overexpressing cells sorted out by FACS technique as side population (SP) were found to be significantly more responsive to SN-38 (ABCG2 and ABCB1 substrate anticancer drug) in the presence of vatalanib. The anchorage independent soft agar colony formation capacity of the SP cells was remarkably reduced upon treatment with a combination of SN-38 and vatalanib, compared to SN-38 alone. However, vatalanib, at concentrations that produced the circumvention of the transporters-mediated resistance, did not appreciably alter ABCG2/ABCB1 mRNA or protein expression levels or the phosphorylation of Akt and extracellular signal-regulated kinase (ERK1/2). Our study thus advocates the further investigation of vatalanib for use in combination chemotherapy to eradicate drug-resistant cancer cells under hypoxia.
Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Inibidores da Angiogênese/farmacologia , Neoplasias do Colo/tratamento farmacológico , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Neoplasias/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos Fitogênicos/agonistas , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Camptotecina/agonistas , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Hipóxia Celular , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Células HEK293 , Humanos , Irinotecano , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Ftalazinas/farmacologia , Proteínas Proto-Oncogênicas c-kit/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-kit/metabolismo , Piridinas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismoRESUMO
Aim To investigate the reversal effect of vatalanib, a novel kinase inhibitor, on multidrug re-sistance in cancer cells and its mechanism. Methods The cytotoxicity and reversal effects of vatalanib were evaluated in both resistant and sensitive tumor cell lines by MTS or SRB assays. The intracellular accumu-lation of fluorescence substrates ( Rh-123 , MX and ADR for P-gp, BCRP, MRP1, respectively) were ana-lysed by flow cytometry. Western blot or qRT-PCR was used to determine the protein or mRNA expression lev-el of BCRP. The effect of vatalanib on ATPase activity of BCRP was determined using crude membranes pre-pared from HEK293/ABCG2 cells. Results Vata-lanib at the nontoxic dose ( 5 μmol · L-1 ) potentially reversed BCRP-mediated MDR in cancer cells, howev-er it had no effect on P-gp or MRP1 mediated MDR. Vatalanib did not alter the intracellular accumulation of MX in HEK 2 9 3 / ABCG 2 , and had no influence on the BCRP-mediated drug efflux. The ATPase assay indica-ted that vatalanib may serve as a substrate of BCRP. Furthermore, vatalanib dramatically suppressed levels of both the protein and mRNA expression of BCRP in concentration-and time-dependent manners. However, reversal concentration of vatalanib had no influence on the total and phosphorylated forms of AKT and ERK1/ 2 in resistant cancer cells. Conclusion Vatalanib could significantly reverse BCRP-mediated MDR with specificity, and its mechanism may correlate with the down-regulation levels of BCRP both mRNA and pro-tein in resistant cancer cells.