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1.
J Pathol ; 262(1): 76-89, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37842959

RESUMO

A 'classical' and a 'basal-like' subtype of pancreatic cancer have been reported, with differential expression of GATA6 and different dosages of mutant KRAS. We established in situ detection of KRAS point mutations and mRNA panels for the consensus subtypes aiming to project these findings to paraffin-embedded clinical tumour samples for spatial quantitative analysis. We unveiled that, next to inter-patient and intra-patient inter-ductal heterogeneity, intraductal spatial phenotypes exist with anti-correlating expression levels of GATA6 and KRASG12D . The basal-like mRNA panel better captured the basal-like cell states than widely used protein markers. The panels corroborated the co-existence of the classical and basal-like cell states in a single tumour duct with functional diversification, i.e. proliferation and epithelial-to-mesenchymal transition respectively. Mutant KRASG12D detection ascertained an epithelial origin of vimentin-positive cells in the tumour. Uneven spatial distribution of cancer-associated fibroblasts could recreate similar intra-organoid diversification. This extensive heterogeneity with functional cooperation of plastic tumour cells poses extra challenges to therapeutic approaches. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Neoplasias Pancreáticas/patologia , Fenótipo , RNA Mensageiro , Carcinoma Ductal Pancreático/patologia
2.
BMC Cancer ; 24(1): 723, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38872153

RESUMO

BACKGROUND: Among the 10% of pancreatic cancers that occur in a familial context, around a third carry a pathogenic variant in a cancer predisposition gene. Genetic studies of pancreatic cancer predisposition are limited by high mortality rates amongst index patients and other affected family members. The genetic risk for pancreatic cancer is often shared with breast cancer susceptibility genes, most notably BRCA2, PALB2, ATM and BRCA1. Therefore, we hypothesized that additional shared genetic etiologies might be uncovered by studying families presenting with both breast and pancreatic cancer. METHODS: Focusing on a multigene panel of 276 DNA Damage Repair (DDR) genes, we performed next-generation sequencing in a cohort of 41 families with at least three breast cancer cases and one pancreatic cancer. When the index patient with pancreatic cancer was deceased, close relatives (first or second-degree) affected with breast cancer were tested (39 families). RESULTS: We identified 27 variants of uncertain significance in DDR genes. A splice site variant (c.1605 + 2T > A) in the RAD17 gene stood out, as a likely loss of function variant. RAD17 is a checkpoint protein that recruits the MRN (MRE11-RAD50-NBS1) complex to initiate DNA signaling, leading to DNA double-strand break repair. CONCLUSION: Within families with breast and pancreatic cancer, we identified RAD17 as a novel candidate predisposition gene. Further genetic studies are warranted to better understand the potential pathogenic effect of RAD17 variants and in other DDR genes.


Assuntos
Neoplasias da Mama , Predisposição Genética para Doença , Neoplasias Pancreáticas , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Sequenciamento de Nucleotídeos em Larga Escala , Proteínas Nucleares , Neoplasias Pancreáticas/genética , Linhagem
3.
Bioorg Med Chem Lett ; 79: 129066, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36410591

RESUMO

Treatment of advanced stage epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) is often complicated by the occurrence of acquired resistance, which emphasizes the need for improved treatment options. Based on a previously reported structure-activity relationship (SAR) study of Spautin-1, which resulted in the discovery of 10a, the search for more potent analogues was envisaged through optimization of the amine substituent. Our search led to the discovery of analogue 15b, harbouring the 2-[4-(4-fluoro-phenoxy)-phenyl]ethylamine substituent, among other potent and original analogues, with nanomolar activity towards EGFR-mutant NSCLC cells. Moreover, this compound 15b showed good selectivity for cancer cells over healthy lung epithelial cells and provides additive effects with food and drug administration (FDA) approved EGFR-tyrosine kinase inhibitors (TKIs), as proven by the co-administration of 15b with Afatinib. Altogether, we report promising lead compounds which show the potential to improve current treatment options.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/efeitos dos fármacos , Receptores ErbB/genética , Neoplasias Pulmonares/tratamento farmacológico , Quinazolinas/química , Quinazolinas/farmacologia
4.
Int J Cancer ; 148(10): 2579-2593, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33210294

RESUMO

In non-small cell lung cancer (NSCLC), activating mutations in the epidermal growth factor receptor (EGFR) induce sensitivity to EGFR tyrosine kinase inhibitors. Despite impressive clinical responses, patients ultimately relapse as a reservoir of drug-tolerant cells persist, which ultimately leads to acquired resistance mechanisms. We performed an unbiased high-throughput siRNA screen to identify proteins that abrogate the response of EGFR-mutant NSCLC to EGFR-targeted therapy. The deubiquitinase USP13 was a top hit resulting from this screen. Targeting USP13 increases the sensitivity to EGFR inhibition with small molecules in vitro and in vivo. USP13 selectively stabilizes mutant EGFR in a peptidase-independent manner by counteracting the action of members of the Cbl family of E3 ubiquitin ligases. We conclude that USP13 is a strong mutant EGFR-specific cotarget that could improve the treatment efficacy of EGFR-targeted therapies.

5.
Int J Mol Sci ; 22(2)2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33435251

RESUMO

Lung cancer is one of the most frequently diagnosed cancers accounting for the highest number of cancer-related deaths in the world. Despite significant progress including targeted therapies and immunotherapy, the treatment of advanced lung cancer remains challenging. Targeted therapies are highly efficacious at prolonging life, but not curative. In prior work we have identified Ubiquitin Specific Protease 13 (USP13) as a potential target to significantly enhance the efficacy of mutant EGFR inhibition. The current study aimed to develop lead molecules for the treatment of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) by developing potent USP13 inhibitors initially starting from Spautin-1, the only available USP13 inhibitor. A SAR study was performed which revealed that increasing the chain length between the secondary amine and phenyl group and introducing a halogen capable of inducing a halogen bond at position 4' of the phenyl group, dramatically increased the activity. However, we could not confirm the binding between Spautin-1 (or its analogues) and USP13 using isothermal titration calorimetry (ITC) or thermal shift assay (TSA) but do not exclude binding under physiological conditions. Nevertheless, we found that the anti-proliferative activity displayed by Spautin-1 towards EGFR-mutant NSCLC cells in vitro was at least partially associated with kinase inhibition. In this work, we present N-[2-(substituted-phenyl)ethyl]-6-fluoro-4-quinazolinamines as promising lead compounds for the treatment of NSCLC. These analogues are significantly more effective towards EGFR-mutant NSCLC cells than Spautin-1 and act as potent never in mitosis A related kinase 4 (NEK4) inhibitors (IC50~1 µM) with moderate selectivity over other kinases.


Assuntos
Benzilaminas/farmacologia , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Neoplasias Pulmonares/enzimologia , Quinases Relacionadas a NIMA/antagonistas & inibidores , Quinazolinas/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Benzilaminas/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Terapia de Alvo Molecular , Mutação , Proteínas de Neoplasias/antagonistas & inibidores , Quinazolinas/uso terapêutico , Relação Estrutura-Atividade
6.
NPJ Precis Oncol ; 8(1): 70, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38485987

RESUMO

At least 40% of human cancers are associated with aberrant ERK pathway activity (ERKp). Inhibitors targeting various effectors within the ERKp have been developed and explored for over two decades. Conversely, a substantial body of evidence suggests that both normal human cells and, notably to a greater extent, cancer cells exhibit susceptibility to hyperactivation of ERKp. However, this vulnerability of cancer cells remains relatively unexplored. In this review, we reexamine the evidence on the selective lethality of highly elevated ERKp activity in human cancer cells of varying backgrounds. We synthesize the insights proposed for harnessing this vulnerability of ERK-associated cancers for therapeutical approaches and contextualize these insights within established pharmacological cancer-targeting models. Moreover, we compile the intriguing preclinical findings of ERK pathway agonism in diverse cancer models. Lastly, we present a conceptual framework for target discovery regarding ERKp agonism, emphasizing the utilization of mutual exclusivity among oncogenes to develop novel targeted therapies for precision oncology.

7.
Cancers (Basel) ; 15(9)2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37174055

RESUMO

Tyrosine kinase inhibitors (TKI) targeting the epidermal growth factor receptor (EGFR) have significantly prolonged survival in EGFR-mutant non-small cell lung cancer patients. However, the development of resistance mechanisms prohibits the curative potential of EGFR TKIs. Combination therapies emerge as a valuable approach to preventing or delaying disease progression. Here, we investigated the combined inhibition of polo-like kinase 1 (PLK1) and EGFR in TKI-sensitive EGFR-mutant NSCLC cells. The pharmacological inhibition of PLK1 destabilized EGFR levels and sensitized NSCLC cells to Osimertinib through induction of apoptosis. In addition, we found that c-Cbl, a ubiquitin ligase of EGFR, is a direct phosphorylation target of PLK1 and PLK1 impacts the stability of c-Cbl in a kinase-dependent manner. In conclusion, we describe a novel interaction between mutant EGFR and PLK1 that may be exploited in the clinic. Co-targeting PLK1 and EGFR may improve and prolong the clinical response to EGFR TKI in patients with an EGFR-mutated NSCLC.

8.
J Med Case Rep ; 17(1): 195, 2023 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-37179382

RESUMO

INTRODUCTION: Pure androgen-secreting adrenocortical tumors are a rare but important cause of peripheral precocious puberty. CASE PRESENTATION: Here, we report a pure androgen-secreting adrenocortical tumor in a 2.5-year-old boy presenting with penile enlargement, pubic hair, frequent erections, and rapid linear growth. We confirmed the diagnosis through laboratory tests, medical imaging, and histology. Furthermore, genetic testing detected a pathogenic germline variant in the TP53 gene, molecularly confirming underlying Li-Fraumeni syndrome. DISCUSSION: Only 15 well-documented cases of pure androgen-secreting adrenocortical tumors have been reported so far. No clinical or imaging signs were identified to differentiate adenomas from carcinomas, and no other cases of Li-Fraumeni syndrome were diagnosed in the four patients that underwent genetic testing. However, diagnosing Li-Fraumeni syndrome is important as it implies a need for intensive tumor surveillance and avoidance of ionizing radiation. CONCLUSION: In this article, we emphasize the need to screen for TP53 gene variants in children with androgen-producing adrenal adenomas and report an association with arterial hypertension.


Assuntos
Neoplasias do Córtex Suprarrenal , Síndrome de Li-Fraumeni , Puberdade Precoce , Masculino , Criança , Humanos , Pré-Escolar , Síndrome de Li-Fraumeni/complicações , Síndrome de Li-Fraumeni/diagnóstico , Síndrome de Li-Fraumeni/genética , Genes p53 , Androgênios , Puberdade Precoce/etiologia , Neoplasias do Córtex Suprarrenal/complicações , Neoplasias do Córtex Suprarrenal/genética
9.
Cell Death Dis ; 13(7): 611, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35840561

RESUMO

Non-small cell lung cancer (NSCLC) patients harboring activating mutations in epidermal growth factor receptor (EGFR) are sensitive to therapy with EGFR tyrosine kinase inhibitors (TKI). Despite remarkable clinical responses using EGFR TKI, surviving drug tolerant cells serve as a reservoir from which drug resistant tumors may emerge. This study addresses the need for improved efficacy of EGFR TKI by identifying targets involved in functional drug tolerance against them. To this aim, a high-throughput siRNA kinome screen was performed using two EGFR TKI-sensitive EGFR-mutant NSCLC cell lines in the presence/absence of the second-generation EGFR TKI afatinib. From the screen, Serine/Threonine/Tyrosine Kinase 1 (STYK1) was identified as a target that when downregulated potentiates the effects of EGFR inhibition in vitro. We found that chemical inhibition of EGFR combined with the siRNA-mediated knockdown of STYK1 led to a significant decrease in cancer cell viability and anchorage-independent cell growth. Further, we show that STYK1 selectively interacts with mutant EGFR and that the interaction is disrupted upon EGFR inhibition. Finally, we identified fibroblast growth factor 1 (FGF1) as a downstream effector of STYK1 in NSCLC cells. Accordingly, downregulation of STYK1 counteracted the afatinib-induced upregulation of FGF1. Altogether, we unveil STYK1 as a valuable target to repress the pool of surviving drug tolerant cells arising upon EGFR inhibition. Co-targeting of EGFR and STYK1 could lead to a better overall outcome for NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Tolerância a Medicamentos , Neoplasias Pulmonares , Inibidores de Proteínas Quinases , Afatinib/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Tolerância a Medicamentos/genética , Tolerância a Medicamentos/fisiologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Fator 1 de Crescimento de Fibroblastos/metabolismo , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , RNA Interferente Pequeno/genética , Receptores Proteína Tirosina Quinases/metabolismo
10.
Oncogene ; 39(37): 6009-6023, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32772043

RESUMO

Aurora B kinase plays essential roles in mitosis. Its protein levels increase before the onset of mitosis and sharply decrease during mitosis exit. The latter decrease is due to a balance between the actions of the E3 ubiquitin ligase anaphase-promoting complex or cyclosome (activated by the Cdh1 adapter), and the deubiquitinating enzyme USP35. Aurora B also executes important functions in interphase. Abnormal modulation of Aurora B in interphase leads to cell cycle defects often linked to aberrant chromosomal condensation and segregation. Very little is however known about how Aurora B levels are regulated in interphase. Here we found that USP13-associates with and stabilizes Aurora B in cells, especially before their entry into mitosis. In order for USP13 to exert its stabilizing effect on Aurora B, their association is promoted by the Aurora B-mediated phosphorylation of USP13 at Serine 114. We also present evidence that USP13 instigates Aurora B deubiquitination and/or protect it from degradation in a non-catalytic manner. In addition, we report that genetic or chemical modulation of the cellular levels/activity of USP13 affects unperturbed cell-cycle progression. Overall our study unveils the molecular and cellular connections of the USP13-Aurora B axis, which potentially participates in the rewiring of the cell cycle happening in cancer cells.


Assuntos
Aurora Quinase B/metabolismo , Ciclo Celular/genética , Endopeptidases/genética , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Progressão da Doença , Endopeptidases/metabolismo , Estabilidade Enzimática , Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Fosforilação , Ligação Proteica , Serina/metabolismo , Proteases Específicas de Ubiquitina
11.
Pathogens ; 9(6)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580355

RESUMO

The public health goal of onchocerciasis in Africa has advanced from control to elimination. In this light, accurate diagnosis is necessary to determine treatment endpoints and confirm elimination, as well as to conduct surveillance for the identification of any possible recrudescence of the disease. Currently, the monitoring of onchocerciasis elimination relies on the Ov-16 test. However, this test is unable to discriminate between past and active infections. Furthermore, about 15-25% of infected persons are reported to be negative for the Ov-16 test, giving a misleading sense of security to false-negative individuals who might continue to serve as reservoirs for infections. Therefore, we opted to design and validate a more sensitive and specific chimeric antigen (OvMANE1) for onchocerciasis diagnosis, using previously reported immunodominant peptides of O. volvulus, the parasite responsible for the disease. In silico analysis of OvMANE1 predicted it to be more antigenic than its individual peptides. We observed that OvMANE1 reacts specifically and differentially with sera from O. volvulus infected and non-infected individuals, as well as with sera from communities of different levels of endemicity. Moreover, we found that total IgG, unlike IgG4 subclass, positively responded to OvMANE1, strongly suggesting its complementarity to the Ov-16 diagnostic tool, which detects Ov-16 IgG4 antibodies. Overall, OvMANE1 exhibited the potential to be utilized in the development of specific diagnostic tools-based on both antibody capture and antigen capture reactions-which are indispensable to monitor the progress of onchocerciasis elimination programs.

12.
J Control Release ; 299: 107-120, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30797866

RESUMO

The tumor microenvironment of numerous prevalent cancer types is abundantly infiltrated with tumor-associated macrophages (TAMs). Macrophage mannose receptor (MMR or CD206) expressing TAMs have been shown to be key promoters of tumor progression and major opponents of successful cancer therapy. Therefore, depleting MMR+ TAMs is an interesting approach to synergize with current antitumor therapies. We studied the potential of single-domain antibodies (sdAbs) specific for MMR to target proteins to MMR+ TAMs. Anti-MMR sdAbs were genetically coupled to a reporter protein, mWasabi (wasabi green, WG), generating sdAb "drug" fusion proteins (SFPs), referred to as WG-SFPs. The resulting WG-SFPs were highly efficient in targeting MMR+ macrophages both in vitro and in vivo. As we showed that second mitochondria-derived activator of caspase (SMAC) mimetics modulate MMR+ macrophages, we further coupled the anti-MMR sdAb to an active form of SMAC, referred to as tSMAC. The resulting tSMAC-SFPs were able to bind and upregulate caspase3/7 activity in MMR+ macrophages in vitro. In conclusion, we report the proof-of-concept of an elegant approach to conjugate anti-MMR sdAbs to proteins, which opens new avenues for targeted manipulation of MMR+ tumor-promoting TAMs.


Assuntos
Sistemas de Liberação de Medicamentos , Lectinas Tipo C/metabolismo , Macrófagos/efeitos dos fármacos , Lectinas de Ligação a Manose/metabolismo , Receptores de Superfície Celular/metabolismo , Anticorpos de Domínio Único/administração & dosagem , Animais , Proteínas Reguladoras de Apoptose/administração & dosagem , Proteínas Reguladoras de Apoptose/farmacologia , Feminino , Células HEK293 , Humanos , Macrófagos/metabolismo , Receptor de Manose , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/administração & dosagem , Proteínas Mitocondriais/farmacologia , Modelos Moleculares , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/farmacologia , Anticorpos de Domínio Único/farmacologia , Microambiente Tumoral/efeitos dos fármacos
13.
Oncogene ; 38(31): 5933-5941, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31285551

RESUMO

Two out of 41 non-small cell lung cancer patients enrolled in a clinical study were found with a somatic CRAF mutation in their tumor, namely CRAFP261A and CRAFP207S. To our knowledge, both mutations are novel in lung cancer and CRAFP261A has not been previously reported in cancer. Expression of CRAFP261A in HEK293T cells and BEAS-2B lung epithelial cells led to increased ERK pathway activation in a dimer-dependent manner, accompanied with loss of CRAF phosphorylation at the negative regulatory S259 residue. Moreover, stable expression of CRAFP261A in mouse embryonic fibroblasts and BEAS-2B cells led to anchorage-independent growth. Consistent with a previous report, we could not observe a gain-of-function with CRAFP207S. Type II but not type I RAF inhibitors suppressed the CRAFP261A-induced ERK pathway activity in BEAS-2B cells, and combinatorial treatment with type II RAF inhibitors and a MEK inhibitor led to a stronger ERK pathway inhibition and growth arrest. Our findings suggest that the acquisition of a CRAFP261A mutation can provide oncogenic properties to cells, and that such cells are sensitive to combined MEK and type II RAF inhibitors. CRAF mutations should be diagnostically and therapeutically explored in lung and perhaps other cancers.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , MAP Quinase Quinase Quinases/antagonistas & inibidores , Mutação , Proteínas Proto-Oncogênicas c-raf/genética , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Células HEK293 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-raf/antagonistas & inibidores
14.
BMC Res Notes ; 11(1): 751, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30348204

RESUMO

OBJECTIVE: Our aim was to produce a mono-biotinylated single domain antibody ('nanobody') specific for the epidermal growth factor receptor (EGFR), which is overexpressed in many cancer cells. The binding of the nanobody and its function are tested in cancer cells. The construct could be used to carry variable therapeutic or diagnostic load using biotin-streptavidin bridging. RESULTS: The EGFR-specific 7D12 nanobody was genetically fused to an IgA hinge linker and to a C-terminal biotin ligase acceptor sequence, allowing mono-biotinylation in E. coli. Expression was in strain BL21-DE3 from a T7 RNA polymerase driven pET22b vector. The biotinylated nanobody, isolated from the periplasm, was purified using streptavidin-mutein affinity chromatography. Final yields were up to 5 mg/l of cell culture. We showed that the construct could bind to EGFR expressing A431 epidermoid carcinoma cells, and to transiently transformed EGFR overexpressing HEK293T cells and not to EGFR negative control cells. The specificity for the EGFR was further demonstrated by immunoprecipitation. To test the functionality, PC9 non-small cell lung cancer cells were treated with mono-biotinylated nanobody or with streptavidin-coupled tetravalent nanobodies. Both were able to block mutant EGFR phosphorylation and slow down growth of PC9 cells. Tetravalent nanobodies were able to downregulate AKT phosphorylation.


Assuntos
Receptores ErbB/imunologia , Escherichia coli , Periplasma , Anticorpos de Domínio Único , Estreptavidina , Linhagem Celular Tumoral , Células HEK293 , Humanos
15.
Oncotarget ; 9(22): 16110-16123, 2018 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-29662630

RESUMO

A large fraction of somatic driver BRAF mutations in lung cancer are non-V600 and impaired-kinase. Non-V600 BRAF mutations predict sensitivity to combination of a type I RAF inhibitor, Dabrafenib, and a MEK inhibitor, Trametinib. Singly, Dabrafenib only weakly suppresses mutant BRAF-induced ERK signaling and can induce ERK paradoxical activation in CRAF-overexpressing cells. The present study compared the effects of Dabrafenib and a type II RAF inhibitor, AZ628, on ERK activity in HEK293T cells expressing several tumor-derived BRAF mutants, and in a non-V600 and impaired-kinase BRAF-mutant lung cancer cell line (H1666). Unlike Dabrafenib, AZ628 did not induce paradoxical ERK activation in CRAF-overexpressing cells and BRAF-mutant cells overexpressing CRAF were more responsive to AZ628 compared to Dabrafenib in terms of ERK inhibition. AZ628 inhibited ERK more effectively than Dabrafenib in both H1666 cells and HEK293T cells co-expressing several different BRAF-mutants with CRAF. Similarly, AZ628 plus Trametinib had better MEK-inhibitory and pro-apoptotic effects in H1666 cells than Dabrafenib plus Trametinib. Moreover, prolonged treatment of H1666 cells with AZ628 plus Trametinib produced greater inhibition of cell growth than Dabrafenib plus Trametinib. These results indicate that AZ628 has greater potential than Dabrafenib, both as a single agent and combined with Trametinib, for the treatment of non-V600 BRAF mutant lung cancer.

16.
Oncotarget ; 9(47): 28731-28744, 2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29983892

RESUMO

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in cancer cells without causing damage to normal cells. However, some tumors are resistant to TRAIL monotherapy and clinical studies assessing targeted agents towards the TRAIL receptor have failed to show robust therapeutic activity. Evidence has shown that standard anti-mitotic drugs can induce synergistic apoptosis upon combination with TRAIL via cell cycle arrest. Polo like kinase-1 (PLK1) plays a critical role in different stages of cell cycle progression and mitosis. A number of investigations have demonstrated that PLK1 inhibition causes cell cycle arrest and mitotic catastrophe in non-small cell lung cancer (NSCLC), and we thus postulated that PLK1 inhibition could enhance TRAIL-induced apoptosis. We demonstrate that the combination of a TRAIL receptor agonist and a PLK1 inhibitor synergistically reduces cell viability, and strongly increases apoptosis in NSCLC cellular models. Consistent with our in vitro observations, this drug combination also significantly reduces tumor growth in vivo. Our data additionally reveal that G2/M cell cycle arrest and downregulation of Mcl-1 and signal transducer and activator of transcription 3 (STAT3) activity following PLK1 inhibition may contribute to the sensitization of TRAIL-induced apoptosis in NSCLC. Together, these data support the further exploration of combined TRAIL and PLK1 inhibition in the treatment of NSCLC.

17.
Oncotarget ; 8(36): 60094-60108, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28947956

RESUMO

Approximately half of BRAF-mutated Non-small cell lung cancers (NSCLCs) harbor a non-V600 BRAF mutation, accounting for ∼40,000 annual deaths worldwide. Recent studies have revealed the benefits of combined targeted therapy with a RAF-inhibitor (Dabrafenib) and a MEK-inhibitor (Trametinib) in treating V600 BRAF mutant cancers, including NSCLC. In contrast, sensitivity of non-V600 BRAF mutations to these inhibitors is not documented. Non-V600 mutations can either increase or impair BRAF kinase activity. However, impaired BRAF kinases can still activate the ERK pathway in a CRAF-dependent manner. Herein, beyond describing a cohort of BRAF mutant NSCLC patients and functionally analyzing 13 tumor-derived BRAF mutations, we demonstrate that both types of non-V600 BRAF mutations can be sensitive to clinically relevant doses of Dabrafenib and Trametinib in HEK293T cells, in lung epithelial cellular model (BEAS-2B) and in human cancer cell lines harboring non-V600 BRAF mutations. ERK activity induced by both types of these mutations is further reduced by combinatorial drug treatment. Moreover, the combination leads to more prolonged ERK inhibition and has anti-proliferative and pro-apoptotic effects in cells harboring both types of non-V600 BRAF mutations. This study provides a basis for the clinical exploration of non-V600 BRAF mutant lung cancers upon treatment with Trametinib and Dabrafenib.

18.
Oncotarget ; 7(3): 3068-83, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26689995

RESUMO

Somatic mutations found within the tyrosine kinase domain (TKD) of the human epidermal growth factor (HER) family of receptors have been implicated in the development and progression of non-small cell lung cancer (NSCLC). However, no conclusive reports have described pathogenic mutations in kinase-impaired HER3. Here, we report a case of an advanced chemotherapy-resistant NSCLC, harboring a novel HER3(V855A) somatic mutation homologous to the EGFR(L858R)activating mutation. Co-expression of HER3(V855A) and wild-type HER2 enhances ligand-induced transformation of murine and human cell lines, while HER-targeted inhibitors potently suppress mutant HER3 activity. Consistent with these observations, in silico computational modeling predicts that mutant V855A alters the kinase domain and c-terminal end of the HER3 protein. Taken together, these findings provide a basis for the clinical exploration of targeted therapies in HER3 mutant NSCLC and by extrapolation, in other cancers that more frequently carry somatic HER3 mutations.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Cloridrato de Erlotinib/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Inibidores de Proteínas Quinases/uso terapêutico , Receptor ErbB-3/genética , Adolescente , Sequência de Aminoácidos , Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/secundário , Linhagem Celular Tumoral , Cristalografia por Raios X , Receptores ErbB/genética , Predisposição Genética para Doença , Humanos , Neoplasias Pulmonares/patologia , Masculino , Dados de Sequência Molecular , Mutação/genética , Neuregulina-1/metabolismo , Fosforilação , Estudos Prospectivos , Estrutura Terciária de Proteína , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Tomografia Computadorizada por Raios X
19.
Cell Death Dis ; 7(12): e2560, 2016 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-28005077

RESUMO

Signal transducer and activator of transcription 5 (STAT5) and nucleophosmin (NPM1) are critical regulators of multiple biological and pathological processes. Although a reciprocal regulatory relationship was established between STAT5A and a NPM-ALK fusion protein in T-cell lymphoma, no direct connection between STAT5 and wild-type NPM1 has been documented. Here we demonstrate a mutually regulatory relationship between STAT5 and NPM1. Induction of STAT5 phosphorylation at Y694 (P-STAT5) diminished NPM1 expression, whereas inhibition of STAT5 phosphorylation enhanced NPM1 expression. Conversely, NPM1 not only negatively regulated STAT5 phosphorylation but also preserved unphosphorylated STAT5 level. Mechanistically, we show that NPM1 downregulation by P-STAT5 is mediated by impairing the BRCA1-BARD1 ubiquitin ligase, which controls the stability of NPM1. In turn, decreased NPM1 levels led to suppression of p53 expression, resulting in enhanced cell survival. This study reveals a new STAT5 signaling pathway regulating p53 expression via NPM1 and uncovers new therapeutic targets for anticancer treatment in tumors driven by STAT5 signaling.


Assuntos
Proteína BRCA1/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Fator de Transcrição STAT5/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Linhagem Celular , Sobrevivência Celular , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Modelos Biológicos , Nucleofosmina , Fosforilação , Fosfotirosina/metabolismo , Ligação Proteica , Proteólise
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