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1.
Semin Pediatr Surg ; 32(6): 151355, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38043262

RESUMO

The 2015 Sustainable Development Goals emphasise good health to all with reduced inequalities, and surgical and anaesthesia care is essential to achieve these. https://sdgs.un.org/goals. However, it has been estimated that 1.7 billion children do not have access to safe anaesthesia and surgery when needed and this disproportionately affects children in low- and middle-income countries (1). It is alarming that 1 in 10 individuals in LMICs do not have access to safe surgical care. Both safe surgery and anaesthesia are essential for ensuring that individuals receive proper medical attention. Economically viable public health initiatives that can avert many disability-adjusted years are needed. (2-4) Morbidity and mortality from surgical disease and anaesthesia care remain high in low-income countries, unlike in high-income countries. The incidence of severe anaesthesia-related critical events and perioperative cardiac arrest is between three and ten times more in LMICs than in HICs (5-7) A baseline POMR that is 100 times higher in LMICs compared to HICs is reported. (8) This perioperative morbidity and mortality gap is more evident in neonates and younger age groups, especially in children with congenital abnormalities. The challenges facing providers of anaesthesia and perioperative care are multifactorial and include but are not limited to the inadequate workforce, inadequate and inappropriate infrastructure, lack of adequate and appropriately sized equipment, including monitors, and safe monitoring capacity, supply chain challenges for medicines and reusable consumables, unreliable supply of oxygen and blood products, lack of data and research for policy formulation, inadequate resource allocation from governments and lack of safety culture among other things. In paediatrics, this is further multiplied by the variability in the sizes of the patients, from neonates to older children (9).


Assuntos
Anestesia , Anestesiologia , Recém-Nascido , Humanos , Criança , Adolescente , Assistência Perioperatória
2.
Skeletal Radiol ; 52(12): 2497-2501, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37544967

RESUMO

Chondromyxoid fibroma is a rare, benign tumor of the bone with excellent prognosis but a high rate of recurrence. We report a patient presenting with pain and a history of chondromyxoid fibroma of the distal left femur previously treated with multiple prior curettage and bone graft procedures. Magnetic resonance imaging and histopathology indicated a recurrence of tumor. Due to the small size of the tumor recurrence and challenges associated with prior open surgery, the patient underwent cryoablation of the lesion with computed tomography guidance. Follow-up 18 months later indicated a resolution of pain and improvement on magnetic resonance imaging, and no concerns after 20 months. To our knowledge, this is the first reported case of chondromyxoid fibroma treated with cryoablation. This case suggests cryoablation could be considered in the setting of recurrent chondromyxoid fibroma for local tumor control.


Assuntos
Neoplasias Ósseas , Condromatose , Criocirurgia , Fibroma , Humanos , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/cirurgia , Neoplasias Ósseas/patologia , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/cirurgia , Fibroma/diagnóstico por imagem , Fibroma/cirurgia , Fibroma/patologia , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Fêmur/patologia , Dor/cirurgia
3.
bioRxiv ; 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36711936

RESUMO

Targeted therapies have revolutionized cancer chemotherapy. Unfortunately, most patients develop multifocal resistance to these drugs within a matter of months. Here, we used a high-throughput phenotypic small molecule screen to identify MCB-613 as a compound that selectively targets EGFR-mutant, EGFR inhibitor-resistant non-small cell lung cancer (NSCLC) cells harboring diverse resistance mechanisms. Subsequent proteomic and functional genomic screens involving MCB-613 identified its target in this context to be KEAP1, revealing that this gene is selectively essential in the setting of EGFR inhibitor resistance. In-depth molecular characterization demonstrated that (1) MCB-613 binds KEAP1 covalently; (2) a single molecule of MCB-613 is capable of bridging two KEAP1 monomers together; and, (3) this modification interferes with the degradation of canonical KEAP1 substrates such as NRF2. Surprisingly, NRF2 knockout sensitizes cells to MCB-613, suggesting that the drug functions through modulation of an alternative KEAP1 substrate. Together, these findings advance MCB-613 as a new tool for exploiting the selective essentiality of KEAP1 in drug-resistant, EGFR-mutant NSCLC cells.

4.
Cell Signal ; 102: 110534, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36442589

RESUMO

Gα13, a heterotrimeric G protein α subunit of the G12/13 subfamily, is an oncogenic driver in multiple cancer types. Unlike other G protein subfamilies that contribute to cancer progression via amino acid substitutions that abolish their deactivating, intrinsic GTPase activity, Gα13 rarely harbors such mutations in tumors and instead appears to stimulate aberrant cell growth via overexpression as a wildtype form. It is not known why this effect is exclusive to the G12/13 subfamily, nor has a mechanism been elucidated for overexpressed Gα13 promoting tumor progression. Using a reporter gene assay for serum response factor (SRF)-mediated transcription in HEK293 cells, we found that transiently expressed, wildtype Gα13 generates a robust SRF signal, approximately half the amplitude observed for GTPase-defective Gα13. When epitope-tagged, wildtype Gα13 was titrated upward in cells, a sharp increase in SRF stimulation was observed coincident with a "spillover" of Gα13 from membrane-associated to a soluble fraction. Overexpressing G protein ß and γ subunits caused both a decrease in this signal and a shift of wildtype Gα13 back to the membranous fraction, suggesting that stoichiometric imbalance in the αßγ heterotrimer results in aberrant subcellular localization and signalling by overexpressed Gα13. We also examined the acylation requirements of wildtype Gα13 for signalling to SRF. Similar to GTPase-defective Gα13, S-palmitoylation of the wildtype α subunit was necessary for SRF activation but could be replaced functionally by an engineered site for N-terminal myristoylation. However, a key difference was observed between wildtype and GTPase-defective Gα13: whereas the latter protein lacking palmitoylation sites was rescued in its SRF signalling by either an engineered polybasic sequence or a C-terminal isoprenylation site, these motifs failed to restore signalling by wildtype, non-palmitoylated Gα13. These findings illuminate several components of the mechanism in which overexpressed, wildtype Gα13 contributes to growth and tumorigenic signalling, and reveal greater stringency in its requirements for post-translational modification in comparison to GTPase-defective Gα13.


Assuntos
Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP , Neoplasias , Humanos , Citoplasma/metabolismo , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Fator de Resposta Sérica/metabolismo
5.
J Vasc Interv Radiol ; 33(7): 841-844, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35777893

RESUMO

Hemorrhagic cystitis (HC) can lead to severe morbidity in treatment-refractory cases. Percutaneous nephrostomy (PCN) drainage was first described in 1993 as a safe, nonoperative procedure to achieve supravesical urinary diversion and treat severe HC. Despite its early success, subsequent studies in the adult population have been limited. This retrospective case series describes long-term outcomes following PCN placement in 24 patients with refractory HC. The overall technical success of the procedure was 100%. Seventeen of 24 (71%) patients experienced resolution of hematuria. The median time for hematuria resolution after the procedure was 12 days (interquartile range, 7-28 days). Postprocedural HC severity grade significantly decreased from a median Grade 3 to Grade 1 (P < .01). The complications included catheter obstruction, dislodgement, and associated urinary tract infections occurring at rates of 1.0, 1.6, and 1.7 per 1,000 catheter days, respectively. This study of PCN placement demonstrated and further confirmed the effectiveness of urinary diversion in treating refractory HC.


Assuntos
Cistite , Derivação Urinária , Adulto , Humanos , Cistite/diagnóstico por imagem , Cistite/etiologia , Cistite/cirurgia , Hematúria/etiologia , Hemorragia/etiologia , Hemorragia/cirurgia , Estudos Retrospectivos , Derivação Urinária/efeitos adversos
6.
Clin Oncol (R Coll Radiol) ; 34(8): e355-e364, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35595594

RESUMO

AIMS: The British Oncology Network for Undergraduate Societies (BONUS) surveyed students who attended an oncology revision day to determine their views on the current quantity, quality and type of curriculum-based oncology teaching they have experienced. MATERIALS AND METHODS: Students attending two BONUS revision days received a questionnaire assessing their experience of oncology teaching within the medical curriculum and interest in pursuing a future career in oncology using a 10-point Likert scale. Data were collected with informed consent to be anonymised and used for research. Student demographics and qualitative and quantitative data about experiences of oncology education were analysed. RESULTS: In total, 451 students registered to attend the revision days. After removal of duplicates, non-responders and non-UK participants, responses from 153 students studying across years 1-6 at 22 UK medical schools were analysed. The mean quantity of oncology lectures students reported receiving was 8.9 hours and the mean quantity of clinic/ward-based oncology teaching was 7.5 hours. Ninety (62.1%) of the 145 students who responded to the relevant question reported that they had received dedicated teaching in oncology. Students who had received dedicated oncology teaching reported a statistically significantly higher mean quality 6.1 (95% confidence interval 5.6-6.5) versus 5.0 (95% confidence interval 4.3-5.5; P = 0.003) and quantity 5.2 (95% confidence interval 4.7-5.6) versus 4.3 (95% confidence interval 3.7-4.9; P = 0.03) of oncology teaching compared with those who had not received this. CONCLUSION: Appropriate oncology education is essential for all medical students due to the high prevalence of cancer. All future doctors need the appropriate knowledge and communication skills to care for cancer patients. Our analysis provides quantitative evidence to support the value of specialist oncology teaching within the medical school curriculum in improving student-reported experience. National student-led revision days and events may widen interest in a future career in oncology and aid collaboration between oncology societies. It is important for the general undergraduate medical curriculum to integrate specialty content. An integrated curriculum should facilitate a holistic approach that spans prevention, screening, treatment and palliation rather than being split by subspeciality.


Assuntos
Educação de Graduação em Medicina , Estudantes de Medicina , Currículo , Humanos , Oncologia , Reino Unido
8.
ESMO Open ; 7(2): 100400, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35247870

RESUMO

BACKGROUND: Microsatellite instability (MSI)/mismatch repair deficiency (dMMR) is a key genetic feature which should be tested in every patient with colorectal cancer (CRC) according to medical guidelines. Artificial intelligence (AI) methods can detect MSI/dMMR directly in routine pathology slides, but the test performance has not been systematically investigated with predefined test thresholds. METHOD: We trained and validated AI-based MSI/dMMR detectors and evaluated predefined performance metrics using nine patient cohorts of 8343 patients across different countries and ethnicities. RESULTS: Classifiers achieved clinical-grade performance, yielding an area under the receiver operating curve (AUROC) of up to 0.96 without using any manual annotations. Subsequently, we show that the AI system can be applied as a rule-out test: by using cohort-specific thresholds, on average 52.73% of tumors in each surgical cohort [total number of MSI/dMMR = 1020, microsatellite stable (MSS)/ proficient mismatch repair (pMMR) = 7323 patients] could be identified as MSS/pMMR with a fixed sensitivity at 95%. In an additional cohort of N = 1530 (MSI/dMMR = 211, MSS/pMMR = 1319) endoscopy biopsy samples, the system achieved an AUROC of 0.89, and the cohort-specific threshold ruled out 44.12% of tumors with a fixed sensitivity at 95%. As a more robust alternative to cohort-specific thresholds, we showed that with a fixed threshold of 0.25 for all the cohorts, we can rule-out 25.51% in surgical specimens and 6.10% in biopsies. INTERPRETATION: When applied in a clinical setting, this means that the AI system can rule out MSI/dMMR in a quarter (with global thresholds) or half of all CRC patients (with local fine-tuning), thereby reducing cost and turnaround time for molecular profiling.


Assuntos
Neoplasias Colorretais , Instabilidade de Microssatélites , Inteligência Artificial , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Reparo de Erro de Pareamento de DNA/genética , Detecção Precoce de Câncer , Humanos
9.
NPJ Precis Oncol ; 6(1): 13, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35233056

RESUMO

The NCI-MATCH was designed to characterize the efficacy of targeted therapies in histology-agnostic driver mutation-positive malignancies. Sub-protocols F and G were developed to evaluate the role of crizotinib in rare tumors that harbored either ALK or ROS1 rearrangements. Patients with malignancies that progressed following at least one prior systemic therapy were accrued to the NCI-MATCH for molecular profiling, and those with actionable ALK or ROS1 rearrangements were offered participation in sub-protocols F or G, respectively. There were five patients who enrolled on Arm F (ALK) and four patients on Arm G (ROS1). Few grade 3 or 4 toxicities were noted, including liver test abnormalities, and acute kidney injury. For sub-protocol F (ALK), the response rate was 50% (90% CI 9.8-90.2%) with one complete response among the 4 eligible patients. The median PFS was 3.8 months, and median OS was 4.3 months. For sub-protocol G (ROS1) the response rate was 25% (90% CI 1.3-75.1%). The median PFS was 4.3 months, and median OS 6.2 months. Data from 3 commercial vendors showed that the prevalence of ALK and ROS1 rearrangements in histologies other than non-small cell lung cancer and lymphoma was rare (0.1% and 0.4% respectively). We observed responses to crizotinib which met the primary endpoint for ALK fusions, albeit in a small number of patients. Despite the limited accrual, some of the patients with these oncogenic fusions can respond to crizotinib which may have a therapeutic role in this setting.

11.
NPJ Breast Cancer ; 7(1): 85, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215753

RESUMO

Management of breast cancer in limited-resource settings is hindered by a lack of low-cost, logistically sustainable approaches toward molecular and cellular diagnostic pathology services that are needed to guide therapy. To address these limitations, we have developed a multimodal cellphone-based platform-the EpiView-D4-that can evaluate both cellular morphology and molecular expression of clinically relevant biomarkers directly from fine-needle aspiration (FNA) of breast tissue specimens within 1 h. The EpiView-D4 is comprised of two components: (1) an immunodiagnostic chip built upon a "non-fouling" polymer brush-coating (the "D4") which quantifies expression of protein biomarkers directly from crude cell lysates, and (2) a custom cellphone-based optical microscope ("EpiView") designed for imaging cytology preparations and D4 assay readout. As a proof-of-concept, we used the EpiView-D4 for assessment of human epidermal growth factor receptor-2 (HER2) expression and validated the performance using cancer cell lines, animal models, and human tissue specimens. We found that FNA cytology specimens (prepared in less than 5 min with rapid staining kits) imaged by the EpiView-D4 were adequate for assessment of lesional cellularity and tumor content. We also found our device could reliably distinguish between HER2 expression levels across multiple different cell lines and animal xenografts. In a pilot study with human tissue (n = 19), we were able to accurately categorize HER2-negative and HER2-positve tumors from FNA specimens. Taken together, the EpiView-D4 offers a promising alternative to invasive-and often unavailable-pathology services and may enable the democratization of effective breast cancer management in limited-resource settings.

12.
Vasc Endovascular Surg ; 55(8): 885-888, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34114524

RESUMO

Portal vein aneurysm (PVA) is a rare entity that can lead to hemorrhage or thrombosis. Although there is no standard treatment, most cases can be managed conservatively; intervention is reserved for symptomatic or enlarging aneurysms. For patients who are not surgical candidates due to cirrhosis and portal hypertension, endovascular creation of a trans-jugular intrahepatic porto-systemic shunt (TIPS) is an option to reduce portal venous pressure. This report describes a case of an enlarging PVA successfully treated with TIPS in a patient with cryptogenic cirrhosis.


Assuntos
Aneurisma , Hipertensão Portal , Derivação Portossistêmica Transjugular Intra-Hepática , Aneurisma/diagnóstico por imagem , Aneurisma/cirurgia , Humanos , Hipertensão Portal/diagnóstico por imagem , Hipertensão Portal/etiologia , Hipertensão Portal/cirurgia , Veia Porta/diagnóstico por imagem , Veia Porta/cirurgia , Resultado do Tratamento
15.
J AOAC Int ; 104(1): 39-48, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33249442

RESUMO

BACKGROUND: Many food recalls are related to the presence of undeclared allergens and microorganisms in food products. To reduce these occurrences, portable diagnostic assay kits are available to quantitate mycotoxins, to detect allergens and gluten in foods and on environmental surfaces, and for sanitation monitoring. OBJECTIVE: This article reviews diagnostic kits that can detect sources of contamination in food and ingredients as well as on surfaces and clean-in-place rinses. METHOD: Mycotoxins and gluten were detected using lateral flow diagnostic assays. Sanitation monitoring of surfaces was completed using a chemiluminescent assay to detect adenosine 5'-triphosphate disodium salt hydrate (ATP) and another assay to detect protein. RESULTS: Gluten was detected at 10 ppm in spiked commodities and on wet and dry surfaces at 2.5 µg/100cm2. Deoxynivalenol was quantitated in dry distillers grains plus solubles and mean results were within two SDs of those determined by HPLC. The chemiluminescent assay had an LOD of 6 fmol of ATP and was able to detect a 1:10 000 dilution of orange juice from surfaces. The protein assay detected 5 µg of bovine serum albumin (BSA) directly applied to the sampler, 100 µg of BSA on surfaces, and detected 1:10 dilutions of Greek yogurt and raw beef from surfaces. CONCLUSIONS: Portable diagnostic kits evaluated in this work provided accurate, rapid, and sensitive results for detection of mycotoxins, gluten, proteins, and ATP. These methods can be used in facilities with minimal training and provide results that are important to ensure food safety. HIGHLIGHTS: Portable methods to detect gluten, mycotoxins, proteins, and ATP are presented.


Assuntos
Alérgenos , Micotoxinas , Alérgenos/análise , Análise de Alimentos , Contaminação de Alimentos/análise , Glutens , Saneamento
16.
BJUI Compass ; 2(2): 126-133, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35474889

RESUMO

Objectives: To study high-frequency 29 MHz transrectal side-fire micro-ultrasound (micro-US) for the detection of clinically significant prostate cancer (csPCa) on prostate biopsy, and validate an image interpretation protocol for micro-US imaging of the prostate. Materials and methods: A prospective randomized clinical trial was performed where 1676 men with indications for prostate biopsy and without known prostate cancer were randomized 1:1 to micro-US vs conventional end-fire ultrasound (conv-US) transrectal-guided prostate biopsy across five sites in North America. The trial was split into two phases, before and after training on a micro-US image interpretation protocol that was developed during the trial using data from the pre-training micro-US arm. Investigators received a standardized training program mid-trial, and the post-training micro-US data were used to examine the training effect. Results: Detection of csPCa (the primary outcome) was no better with the first-generation micro-US system than with conv-US in the overall population (34.6% vs 36.6%, respectively, P = .21). Data from the first portion of the trial were, however, used to develop an image interpretation protocol termed PRI-MUS in order to address the lack of understanding of the appearance of cancer under micro-US. Micro-US sensitivity in the post-training group improved to 60.8% from 24.6% (P < .01), while specificity decreased (from 84.2% to 63.2%). Detection of csPCa in the micro-US arm increased by 7% after training (32% to 39%, P < .03), but training instituted mid-trial did not affect the overall results of the comparison between arms. Conclusion: Micro-US provided no clear benefit over conv-US for the detection of csPCa at biopsy. However, it became evident during the trial that training and increasing experience with this novel technology improved the performance of this first-generation system.

17.
Brain Res ; 1740: 146851, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32339499

RESUMO

The ghrelin system has been garnering interest for its role in different neuropsychiatric disorders, including alcohol use disorder (AUD). Accordingly, targeting the ghrelin system is under investigation as a potential novel therapeutic approach. While alcohol provokes the immune system and inflammatory responses, ghrelin has potent immunomodulatory and anti-inflammatory properties. The present study aimed to shed light on the "crosstalk" between ghrelin and inflammation by examining the effects of exogenous ghrelin administration and ghrelin receptor blockade on peripheral inflammatory markers in the context of two human laboratory studies with alcohol administration. Non-treatment-seeking, heavy-drinking individuals with alcohol dependence, the majority of whom were African American males, were enrolled. In the first randomized, crossover, double-blind, placebo-controlled human laboratory study, participants underwent two experimental paradigms - an intravenous alcohol self-administration (IV-ASA) and an intravenous alcohol clamp (IV-AC) - each consisting of two counterbalanced sessions (ghrelin, placebo). A loading dose of intravenous ghrelin (3 mcg/kg) or placebo, followed by a continuous ghrelin (16.9 ng/kg/min) or placebo infusion was administered. In the second dose-escalating, single-blind, placebo-controlled human laboratory phase 1b study, participants were dosed with an oral ghrelin receptor blocker (PF-5190457) and underwent an oral alcohol challenge. Repeated blood samples were collected, and plasma concentrations of the following inflammatory markers were measured: C-reactive protein (CRP), interleukin (IL)-6, IL-10, IL-18, and tumor necrosis factor alpha (TNF-α). During the IV-ASA experiment, significant drug × time interaction effects were observed for IL-6 (F3,36 = 3.345, p = 0.030) and IL-10 (F3,53.2 = 4.638, p = 0.006), indicating that ghrelin, compared to placebo, significantly reduced blood concentrations of the proinflammatory cytokine IL-6, while increasing blood concentrations of the anti-inflammatory cytokine IL-10. No significant drug × time interaction effects were observed during the IV-AC experiment, possibly because of its much shorter duration and/or smaller sample. Treatment with PF-5190457, compared to placebo, had no significant effect on the inflammatory markers investigated. In conclusion, a supraphysiologic pharmacological challenge with exogenous ghrelin in heavy-drinking individuals produced anti-inflammatory effects in the context of intravenous alcohol administration. On the contrary, ghrelin receptor blockade did not lead to any change in the inflammatory markers included in this study. Mechanistic studies are required to better understand the interaction between ghrelin, alcohol, and inflammatory processes.


Assuntos
Consumo de Bebidas Alcoólicas/sangue , Etanol/administração & dosagem , Grelina/administração & dosagem , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/sangue , Receptores de Grelina/antagonistas & inibidores , Administração Intravenosa , Adulto , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Azetidinas/administração & dosagem , Biomarcadores/sangue , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Autoadministração , Método Simples-Cego , Compostos de Espiro/administração & dosagem
18.
Nature ; 580(7801): 136-141, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238925

RESUMO

Cancer genomics studies have identified thousands of putative cancer driver genes1. Development of high-throughput and accurate models to define the functions of these genes is a major challenge. Here we devised a scalable cancer-spheroid model and performed genome-wide CRISPR screens in 2D monolayers and 3D lung-cancer spheroids. CRISPR phenotypes in 3D more accurately recapitulated those of in vivo tumours, and genes with differential sensitivities between 2D and 3D conditions were highly enriched for genes that are mutated in lung cancers. These analyses also revealed drivers that are essential for cancer growth in 3D and in vivo, but not in 2D. Notably, we found that carboxypeptidase D is responsible for removal of a C-terminal RKRR motif2 from the α-chain of the insulin-like growth factor 1 receptor that is critical for receptor activity. Carboxypeptidase D expression correlates with patient outcomes in patients with lung cancer, and loss of carboxypeptidase D reduced tumour growth. Our results reveal key differences between 2D and 3D cancer models, and establish a generalizable strategy for performing CRISPR screens in spheroids to reveal cancer vulnerabilities.


Assuntos
Sistemas CRISPR-Cas/genética , Técnicas de Cultura de Células/métodos , Proliferação de Células/genética , Genoma Humano/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Esferoides Celulares/patologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Motivos de Aminoácidos , Animais , Carboxipeptidases/antagonistas & inibidores , Carboxipeptidases/deficiência , Carboxipeptidases/genética , Carboxipeptidases/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/metabolismo , Camundongos , Terapia de Alvo Molecular , Mutação , Fenótipo , Receptor IGF Tipo 1/química , Receptor IGF Tipo 1/metabolismo , Transdução de Sinais , Esferoides Celulares/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Nat Genet ; 52(4): 408-417, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32203462

RESUMO

Local adaptation directs populations towards environment-specific fitness maxima through acquisition of positively selected traits. However, rapid environmental changes can identify hidden fitness trade-offs that turn adaptation into maladaptation, resulting in evolutionary traps. Cancer, a disease that is prone to drug resistance, is in principle susceptible to such traps. We therefore performed pooled CRISPR-Cas9 knockout screens in acute myeloid leukemia (AML) cells treated with various chemotherapies to map the drug-dependent genetic basis of fitness trade-offs, a concept known as antagonistic pleiotropy (AP). We identified a PRC2-NSD2/3-mediated MYC regulatory axis as a drug-induced AP pathway whose ability to confer resistance to bromodomain inhibition and sensitivity to BCL-2 inhibition templates an evolutionary trap. Across diverse AML cell-line and patient-derived xenograft models, we find that acquisition of resistance to bromodomain inhibition through this pathway exposes coincident hypersensitivity to BCL-2 inhibition. Thus, drug-induced AP can be leveraged to design evolutionary traps that selectively target drug resistance in cancer.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Pleiotropia Genética/genética , Neoplasias/genética , Adaptação Fisiológica/genética , Animais , Evolução Biológica , Sistemas CRISPR-Cas/genética , Linhagem Celular , Linhagem Celular Tumoral , Meio Ambiente , Aptidão Genética/genética , Células HEK293 , Células HL-60 , Humanos , Camundongos , Proteínas Nucleares/genética , Fenótipo , Locos de Características Quantitativas/genética , Fatores de Transcrição/genética
20.
Cancer Res ; 80(7): 1387-1400, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32005716

RESUMO

The principal unmet need in BRAFV600E-positive melanoma is lack of an adequate therapeutic strategy capable of overcoming resistance to clinically approved targeted therapies against oncogenic BRAF and/or the downstream MEK1/2 kinases. We previously discovered that copper (Cu) is required for MEK1 and MEK2 activity through a direct Cu-MEK1/2 interaction. Repurposing the clinical Cu chelator tetrathiomolybdate (TTM) is supported by efficacy in BRAFV600E-driven melanoma models, due in part to inhibition of MEK1/2 kinase activity. However, the antineoplastic activity of Cu chelators is cytostatic. Here, we performed high-throughput small-molecule screens to identify bioactive compounds that synergize with TTM in BRAFV600E-driven melanoma cells. Genetic perturbation or pharmacologic inhibition of specific members of the BCL2 family of antiapoptotic proteins (BCL-W, BCL-XL, and MCL1) selectively reduced cell viability when combined with a Cu chelator and induced CASPASE-dependent cell death. Further, in BRAFV600E-positive melanoma cells evolved to be resistant to BRAF and/or MEK1/2 inhibitors, combined treatment with TTM and the clinically evaluated BCL2 inhibitor, ABT-263, restored tumor growth suppression and induced apoptosis. These findings further support Cu chelation as a therapeutic strategy to target oncogene-dependent tumor cell growth and survival by enhancing Cu chelator efficacy with chemical inducers of apoptosis, especially in the context of refractory or relapsed BRAFV600E-driven melanoma. SIGNIFICANCE: This study unveils a novel collateral drug sensitivity elicited by combining copper chelators and BH3 mimetics for treatment of BRAFV600E mutation-positive melanoma.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Quelantes/farmacologia , Melanoma/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Compostos de Anilina/farmacologia , Compostos de Anilina/uso terapêutico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Quelantes/uso terapêutico , Cobre/metabolismo , Reposicionamento de Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Células HEK293 , Ensaios de Triagem em Larga Escala , Humanos , Melanoma/genética , Melanoma/patologia , Camundongos , Molibdênio/farmacologia , Molibdênio/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
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