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BACKGROUND: Medical student master's theses are often carried out as research projects, and some are published as research papers in journals. We investigated the percentage of master's theses conducted by 5th -year students at the Medical Degree Program at Lund University, Sweden, that subsequently served as the basis for research publications. In addition, we explored both student and supervisor experiences with the publishing process. METHODS: A cohort of four semesters of student data covering the period from 2019 to 2020 (n = 446) was searched in PubMed, Embase and the Web of Science to assess whether they had been published as research papers. Surveys were sent to students (n = 121) and supervisors (n = 77) to explore their experiences with the publishing process. RESULTS: We found that 33% (149 of 446) of the students in the 2019-2020 cohort subsequently published their theses, and 50% of these students were listed as first authors. Most students published original research. Students (n = 21) and supervisors (n = 44) reported that the publishing process was time-consuming and that students needed multilevel support from supervisors to achieve successful publication. The publishing process was reported by 79% of the students to have led to additional learning. Most of the papers (126 of 149, 85%) had a clinical or patient-oriented focus. CONCLUSION: A high percentage of the student publications in which students are listed as first authors require engagement from both students and supervisors. Supervisors play an essential role in supporting students in a successful publication process. Most of the published papers were either clinical or patient-oriented research.
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Estudiantes de Medicina , Humanos , Edición , Facultades de Medicina , Aprendizaje , InvestigadoresRESUMEN
Molecular targeted therapy using a drug that suppresses the growth and spread of cancer cells via inhibition of a specific protein is a foundation of precision medicine and treatment. High expression of the proto-oncogene Bcl-3 promotes the proliferation and metastasis of cancer cells originating from tissues such as the colon, prostate, breast, and skin. The development of novel drugs targeting Bcl-3 alone or in combination with other therapies can cure these patients or prolong their survival. As a proof of concept, in the present study, we focused on metastatic melanoma as a model system. High-throughput screening and in vitro experiments identified BCL3ANT as a lead molecule that could interfere with Bcl-3-mediated cyclin D1 expression and cell proliferation and migration in melanoma. In experimental animal models of melanoma, it was demonstrated that the use of a Bcl-3 inhibitor can influence the survival of melanoma cells. Since there are no other inhibitors against Bcl-3 in the clinical pipeline for cancer treatment, this presents a unique opportunity to develop a highly specific drug against malignant melanoma to meet an urgent clinical need.
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Melanoma , Neoplasias Cutáneas , Masculino , Animales , Humanos , Melanoma/patología , Ciclina D1/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Neoplasias Cutáneas/patología , Proliferación Celular , Línea Celular Tumoral , ApoptosisRESUMEN
IL-1, plays a role in some pathological inflammatory conditions. This pro-inflammatory cytokine also has a crucial role in tumorigenesis and immune responses in the tumor microenvironment (TME). IL-1 receptor accessory protein (IL-1RAP), combined with IL-1 receptor-1, provides a functional complex for binding and signaling. In addition to the direct role of IL-1, some studies demonstrated that IL1-RAP has essential roles in the progression, angiogenesis, and metastasis of solid tumors such as gastrointestinal tumors, lung carcinoma, glioma, breast and cervical cancers. This molecule also interacts with FLT-3 and c-Kit tyrosine kinases and is involved in the pathogenesis of hematological malignancies such as acute myeloid lymphoma. Additionally, IL-1RAP interacts with solute carrier family 3 member 2 (SLC3A2) and thereby increasing the resistance to anoikis and metastasis in Ewing sarcoma. This review summarizes the role of IL-1RAP in different types of cancers and discusses its targeting as a novel therapeutic approach for malignancies.
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Neoplasias Gastrointestinales , Proteína Accesoria del Receptor de Interleucina-1 , Humanos , Receptores de Interleucina-1 , Interleucina-1/uso terapéutico , Inmunoterapia , Microambiente TumoralRESUMEN
The deregulation of BCL2 family proteins plays a crucial role in leukemia development. Therefore, pharmacological inhibition of this family of proteins is becoming a prevalent treatment method. However, due to the emergence of primary and acquired resistance, efficacy is compromised in clinical or preclinical settings. We developed a drug sensitivity prediction model utilizing a deep tabular learning algorithm for the assessment of venetoclax sensitivity in T-cell acute lymphoblastic leukemia (T-ALL) patient samples. Through analysis of predicted venetoclax-sensitive and resistant samples, PLK1 was identified as a cooperating partner for the BCL2-mediated antiapoptotic program. This finding was substantiated by additional data obtained through phosphoproteomics and high-throughput kinase screening. Concurrent treatment using venetoclax with PLK1-specific inhibitors and PLK1 knockdown demonstrated a greater therapeutic effect on T-ALL cell lines, patient-derived xenografts, and engrafted mice compared with using each treatment separately. Mechanistically, the attenuation of PLK1 enhanced BCL2 inhibitor sensitivity through upregulation of BCL2L13 and PMAIP1 expression. Collectively, these findings underscore the dependency of T-ALL on PLK1 and postulate a plausible regulatory mechanism.
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Leucemia-Linfoma Linfoblástico de Células T Precursoras , Animales , Humanos , Ratones , Algoritmos , Modelos Animales de Enfermedad , Proteínas Proto-Oncogénicas c-bcl-2/genética , Quinasa Tipo Polo 1RESUMEN
Polyploidy and metastasis are associated with a low probability of disease-free survival in cancer patients. Polyploid cells are known to facilitate tumorigenesis. However, few data associate polyploidization with metastasis. Here, by generating and using diploid (2n) and tetraploid (4n) clones from malignant fibrous histiocytoma (MFH) and colon carcinoma (RKO), we demonstrate the migration and invasion advantage of tetraploid cells in vitro using several assays, including the wound healing, the OrisTM two-dimensional cell migration, single-cell migration tracking by video microscopy, the Boyden chamber, and the xCELLigence RTCA real-time cell migration. Motility advantage was observed despite tetraploid cell proliferation weakness. We could also demonstrate preferential metastatic potential in vivo for the tetraploid clone using the tail vein injection in mice and tracking metastatic tumors in the lung. Using the Mitelman Database of Chromosome Aberrations in Cancer, we found an accumulation of polyploid karyotypes in metastatic tumors compared to primary ones. This work reveals the clinical relevance of the polyploid subpopulation and the strategic need to highlight polyploidy in preclinical studies as a therapeutic target for metastasis.
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Neoplasias del Colon , Tetraploidía , Humanos , Animales , Ratones , Poliploidía , Aberraciones Cromosómicas , Neoplasias del Colon/genética , Neoplasias del Colon/tratamiento farmacológicoRESUMEN
SPATA2 mediates the recruitment of CYLD to immune receptor complexes by bridging the interaction of CYLD with the linear ubiquitylation assembly complex (LUBAC) component HOIP. Whether SPATA2 exhibits functions independently of CYLD is unclear. Here, we show that, while Cyld-/- and Spata2-/- mice are viable, double mutants exhibit highly penetrant perinatal lethality, indicating independent functions of SPATA2 and CYLD. Cyld-/-Spata2-/- fibroblasts show increased M1-linked TNFR1-SC ubiquitylation and, similar to Cyld-/-Spata2-/- macrophages and intestinal epithelial cells, elevated pro-inflammatory gene expression compared with Cyld-/- or Spata2-/- cells. We show that SPATA2 competes with OTULIN for binding to HOIP via its PUB-interacting motif (PIM) and its zinc finger domain, thereby promoting autoubiquitylation of LUBAC. Consistently, increased pro-inflammatory signaling in Cyld-/-Spata2-/- cells depends on the presence of OTULIN. Our data therefore indicate that SPATA2 counteracts, independently of CYLD, the deubiquitylation of LUBAC by OTULIN and thereby attenuates LUBAC activity and pro-inflammatory signaling.
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Transducción de Señal , Factores de Transcripción , Animales , Ratones , Ubiquitinación , Factores de Transcripción/metabolismo , FN-kappa B/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Enzima Desubiquitinante CYLD/metabolismoRESUMEN
The bone marrow microenvironment provides indispensable factors to sustain blood production throughout life. It is also a hotspot for the progression of hematologic disorders and the most frequent site of solid tumor metastasis. Preclinical research relies on xenograft mouse models, but these models preclude the human-specific functional interactions of stem cells with their bone marrow microenvironment. Instead, human mesenchymal cells can be exploited for the in vivo engineering of humanized niches, which confer robust engraftment of human healthy and malignant blood samples. However, mesenchymal cells are associated with major reproducibility issues in tissue formation. Here, we report the fast and standardized generation of human mini-bones by a custom-designed human mesenchymal cell line. These resulting humanized ossicles (hOss) consist of fully mature bone and bone marrow structures hosting a human mesenchymal niche with retained stem cell properties. As compared to mouse bones, we demonstrate superior engraftment of human cord blood hematopoietic cells and primary acute myeloid leukemia samples and also validate hOss as a metastatic site for breast cancer cells. We further report the engraftment of neuroblastoma patient-derived xenograft cells in a humanized model, recapitulating clinically described osteolytic lesions. Collectively, our human mini-bones constitute a powerful preclinical platform to model bone-developing tumors using patient-derived materials.
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Leucemia Mieloide Aguda , Nicho de Células Madre , Animales , Huesos , Modelos Animales de Enfermedad , Hematopoyesis , Humanos , Ratones , Reproducibilidad de los Resultados , Microambiente TumoralRESUMEN
Hepatocellular carcinoma (HCC), commonly diagnosed at an advanced stage, is the most common primary liver cancer. Owing to a lack of effective HCC treatments and the commonly acquired chemoresistance, novel therapies need to be investigated. Cyclophilins-intracellular proteins with peptidyl-prolyl isomerase activity-have been shown to play a key role in therapy resistance and cell proliferation. Here, we aimed to evaluate changes in the gene expression of HCC cells caused by cyclophilin inhibition in order to explore suitable combination treatment approaches, including the use of chemoagents, such as cisplatin. Our results show that the novel cyclophilin inhibitor NV651 decreases the expression of genes involved in several pathways related to the cancer cell cycle and DNA repair. We evaluated the potential synergistic effect of NV651 in combination with other treatments used against HCC in cisplatin-sensitive cells. NV651 showed a synergistic effect in inhibiting cell proliferation, with a significant increase in intrinsic apoptosis in combination with the DNA crosslinking agent cisplatin. This combination also affected cell cycle progression and reduced the capacity of the cell to repair DNA in comparison with a single treatment with cisplatin. Based on these results, we believe that the combination of cisplatin and NV651 may provide a novel approach to HCC treatment.
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Interleukin-1 receptor accessory protein (IL-1RAcP) is a member of the immunoglobulin superfamily proteins consisting of soluble and membranous isoforms. IL-1RAcP plays an essential role in the signaling of the IL-1 family cytokines such as IL-1, IL-33 and IL-36, as well as tyrosine kinases FLT3 and C-Kit. IL-1RAcP generally initiates inflammatory signaling pathway through the recruitment of signaling mediators, including MYD88 and IRAK. Chronic inflammation following prolonged signaling of cytokine receptors is a critical process in the pathogenesis of many inflammatory disorders, including autoimmunity, obesity, psoriasis, type 1 diabetes, endometriosis, preeclampsia and Alzheimer's disease. Recently IL-1RAcP aberrant signaling has been considered to play a central role in the pathogenesis of these chronic inflammatory diseases. Targeting IL-1RAcP signaling pathway that was recently considered in clinical trials related to malignancies also indicates its potential as therapeutic target for the inflammatory and autoimmune diseases. This review summarizes the molecular structure, components associated with IL-1RAcP signaling pathways, and their involvement in the pathogenesis of different inflammatory diseases. We will also discuss the effect of IL-1RAcP inhibition for treatment proposes.
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Proteína Accesoria del Receptor de Interleucina-1 , Transducción de Señal , Interleucina-1/metabolismo , Proteína Accesoria del Receptor de Interleucina-1/química , Proteína Accesoria del Receptor de Interleucina-1/metabolismo , Interleucina-33/metabolismo , Unión Proteica , Isoformas de Proteínas/metabolismo , Receptores de Interleucina-1/metabolismoRESUMEN
Hepatocellular carcinoma (HCC), the most common primary liver cancer, is usually diagnosed in its late state. Tyrosine kinase inhibitors such as sorafenib and regorafenib are one of the few treatment options approved for advanced HCC and only prolong the patient's life expectancy by a few months. Therefore, there is a need for novel effective treatments. Cyclophilins are intracellular proteins that catalyze the cis/trans isomerization of peptide bonds at proline residues. Cyclophilins are known to be overexpressed in HCC, affecting therapy resistance and cell proliferation. In the present study, we explored the potential of cyclophilin inhibitors as new therapeutic options for HCC in vitro and in vivo. Our results showed that the novel cyclophilin inhibitor, NV651, was able to significantly decrease proliferation in a diverse set of HCC cell lines. The exposure of HCC cells to NV651 caused an accumulation of cells during mitosis and consequent accumulation in the G2/M phase of the cell cycle. NV651 reduced tumor growth in vivo using an HCC xenograft model without affecting the body weights of the animals. The safety aspects of NV651 were also confirmed in primary human hepatocytes without any cytotoxic effects. Based on the results obtained in this study, we propose NV651 as a potential treatment strategy for HCC.
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Glioblastoma (GB) is the most common and the most aggressive form of brain tumor in adults, which currently lacks efficient treatment strategies. In this study, we investigated the therapeutic effect of function-blocking antibodies targeting integrin α10ß1 on patient-derived-GB cell lines in vitro and in vivo. The in vitro studies demonstrated significant inhibiting effects of the integrin α10 antibodies on the adhesion, migration, proliferation, and sphere formation of GB cells. In a xenograft mouse model, the effect of the antibodies on tumor growth was investigated in luciferase-labeled and subcutaneously implanted GB cells. As demonstrated by in vivo imaging analysis and caliper measurements, the integrin α10-antibodies significantly suppressed GB tumor growth compared to control antibodies. Immunohistochemical analysis of the GB tumors showed lower expression of the proliferation marker Ki67 and an increased expression of cleaved caspase-3 after treatment with integrin α10 antibodies, further supporting a therapeutic effect. Our results suggest that function-blocking antibody targeting integrin α10ß1 is a promising therapeutic strategy for the treatment of glioblastoma.
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The Wnt signalling pathway is a central communication cascade between cells to orchestrate polarity and fate during development and adult tissue homeostasis in various organisms. This pathway can be regulated by different signalling molecules in several steps. One of the coordinators in this pathway is Nemo-like kinase (NLK), which is an atypical proline-directed serine/threonine mitogen-activated protein (MAP) kinase. Very recently, NLK was established as an essential regulator in different cellular processes and abnormal NLK expression was highlighted to affect the development and progression of various diseases. In this review, we focused on the recent discoveries by using NLK-deficient mice, which show a phenotype in the development and function of organs such as the lung, heart and skeleton. Furthermore, NLK could conduct the function and differentiation of cells from the immune system, in addition to regulating neurodegenerative diseases, such as Huntington's disease and spinocerebellar ataxias. Overall, generations of NLK-deficient mice have taught us valuable lessons about the role of this kinase in certain diseases and development.
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Susceptibilidad a Enfermedades , Desarrollo Embrionario/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Biomarcadores , Humanos , Sistema Inmunológico/inmunología , Sistema Inmunológico/metabolismo , Ratones , Neuronas/metabolismo , Vía de Señalización WntRESUMEN
Squamous cell carcinoma caused by ultraviolet light exposure represents over 40% of all malignant diseases. It is one of the most commonly found human tumours. Tumour mass within squamous cell carcinoma consists of various cell types, including cancer-initiating cells that are responsible for tumour progression, metastasis and chemoresistance and implicated in clinical relapse. In the present study, we aimed to characterise whether the cell population with high CD34 and α6-integrin expression behave as cancer-initiating cells within ultraviolet-induced squamous cell carcinoma in mouse skin. CD34highα6-integrinhigh compared to CD34lowα6-integrinhigh cells isolated from ultraviolet-induced squamous cell carcinoma could propagate effectively by displaying greater tumour initiating and self-renewal abilities. Our study suggests that CD34highα6-integrinhigh cells act as initiators upon ultraviolet-induced skin squamous cell carcinoma.
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Drug resistance of childhood cancer neuroblastoma is a serious clinical problem. Patients with relapsed disease have a poor prognosis despite intense treatment. In the present study, we aimed to identify chemoresistance gene expression signatures in vincristine resistant neuroblastoma cells. We found that vincristine-resistant neuroblastoma cells formed larger clones and survived under reduced serum conditions as compared with non-resistant parental cells. To identify the possible mechanisms underlying vincristine resistance in neuroblastoma cells, we investigated the expression profiles of genes known to be involved in cancer drug resistance. This specific gene expression patterns could predict the behavior of a tumor in response to chemotherapy and for predicting the prognosis of high-risk neuroblastoma patients. Our signature could help chemoresistant neuroblastoma patients in avoiding useless and harmful chemotherapy cycles.
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Antineoplásicos Fitogénicos/farmacología , Resistencia a Antineoplásicos/genética , Proteínas de Neoplasias/biosíntesis , Neuroblastoma/genética , Transcriptoma , Vincristina/farmacología , Antineoplásicos/farmacología , Antineoplásicos Fitogénicos/uso terapéutico , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Cisplatino/farmacología , Células Clonales , Etopósido/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Proteínas de Neoplasias/genética , Neuroblastoma/tratamiento farmacológico , Neuroblastoma/patología , Nocodazol/farmacología , Pronóstico , Vincristina/uso terapéuticoRESUMEN
Neuroblastoma is a childhood solid tumour originating from undifferentiated neural progenitor cells of the sympathetic nervous system. Drug resistance of childhood cancer neuroblastoma is a serious clinical problem. In the present study, we aimed to identify novel drugs that can inhibit the growth and survival of chemoresistant neuroblastoma. High-throughput screening identified a small molecule, epi-enprioline that was able to induce apoptosis of vincristine-resistant neuroblastoma cells via the mitochondrial apoptotic pathway. Epi-enprioline reduced tumour growth in multiple preclinical models, including an orthotopic neuroblastoma patient-derived xenograft model in vivo. In summary, our data suggest that epi-enprioline can be considered as a lead compound for the treatment of vincristine-resistant neuroblastoma uncovering a novel strategy, which can be further explored as a treatment for drug-resistant neuroblastoma.
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Antineoplásicos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Neuroblastoma/tratamiento farmacológico , Piridinas/farmacología , Animales , Antineoplásicos/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/farmacología , Ensayos de Selección de Medicamentos Antitumorales/métodos , Femenino , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Ratones , Ratones Desnudos , Bibliotecas de Moléculas Pequeñas/farmacología , Vincristina/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The ß-catenin/Wnt signaling pathway plays an important role in all stages of T cell development. Nemo-like kinase (NLK) is an evolutionary conserved serine/threonine kinase and a negative regulator of the Wnt signaling pathway. NLK can directly phosphorylate histone deacetylase 1 (HDAC1), as well as T cell factor/lymphoid enhancer-binding factor (TCF/LEF), causing subsequent repression of target gene transcription. By engineering mice lacking NLK in early stages of T cell development, we set out to characterize the role NLK plays in T cell development and found that deletion of NLK does not affect mouse health or lymphoid tissue development. Instead, these mice harbored a reduced number of single-positive (SP) CD8+ thymocytes without any defects in the SP CD4+ thymocyte population. The decrease in SP CD8+ thymocytes was not caused by a block in differentiation from double-positive CD4+CD8+ cells. Neither TCR signaling nor activation was altered in the absence of NLK. Instead, we observed a significant increase in cell death and reduced phosphorylation of LEF1 as well as HDAC1 among NLK-deleted SP CD8+ cells. Thus, NLK seems to play an important role in the survival of CD8+ thymocytes. Our data provide evidence for a new function for NLK with regard to its involvement in T cell development and supporting survival of SP CD8+ thymocytes.
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Linfocitos T CD8-positivos/fisiología , Proteínas Serina-Treonina Quinasas/metabolismo , Subgrupos de Linfocitos T/fisiología , Timocitos/fisiología , Animales , Diferenciación Celular , Supervivencia Celular , Histona Desacetilasa 1/metabolismo , Activación de Linfocitos , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal , Proteínas Wnt/metabolismoRESUMEN
Neuroblastoma is the most common paediatric cancer type. Patients diagnosed with high-risk neuroblastoma have poor prognosis and occasionally tumours relapse. As a result, novel treatment strategies are needed for relapse and refractory neuroblastoma patients. Here, we found that high expression of Mps1 kinase (mitotic kinase Monopolar Spindle 1) was associated with relapse-free neuroblastoma patient outcomes and poor overall survival. Silencing and inhibition of Mps1 in neuroblastoma or PDX-derived cells promoted cell apoptosis via the caspase-dependent mitochondrial apoptotic pathway. The mechanism of cell death upon Mps1 inhibition was dependent on the polyploidization/aneuploidization of the cells before undergoing mitotic catastrophe. Furthermore, tumour growth retardation was confirmed in a xenograft mouse model after Mps1-inhibitor treatment. Altogether, these results suggest that Mps1 expression and inhibition can be considered as a novel prognostic marker as well as a therapeutic strategy for the treatment of high-risk neuroblastoma patients.
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Proteínas de Ciclo Celular/antagonistas & inhibidores , Mitosis , Neuroblastoma/enzimología , Neuroblastoma/patología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Animales , Apoptosis/efectos de los fármacos , Biomarcadores de Tumor/metabolismo , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Humanos , Ratones , Mitocondrias/metabolismo , Poliploidía , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND/AIMS: Chromosomal instability is a well-known factor in the progression of different types of cancer, including colorectal cancer. Chromosomal instability results in severely rearranged karyotypes and aneuploidy. Tetraploidy constitutes an intermediate phase during the polyploidy/aneuploidy cascade in oncogenesis, and tetraploid cells are particularly resistant to chemotherapy. Whether inhibition of the mitotic protein polo-like kinase 1 (PLK1) prevents the survival of tetraploid colon cancer cells is unknown. METHODS: Diploid and tetraploid cells were transfected with siPLK1 or treated with PLK1 inhibitor Bi2536 in combination with spindle poison. Cell toxicity was assessed via crystal violet staining and clonogenic assay. Flow cytometry assessment analyzed numerous cell apoptotic parameters and cell cycle phases. Synergistic activity between Bi2536 and paclitaxel, vincristine or colchicine was calculated using the CompuSyn software. RESULTS: Inhibition or abrogation of PLK1 prevented the survival of colon cancer cells, specifically tetraploid cells. The cell death induced by PLK inhibition was due to mitotic slippage, followed by the activation of the intrinsic pathway of apoptosis. We further demonstrated that co-treatment of the tetraploid colon cancer cells with a PLK1 inhibitor and the microtubule polymerisation inhibitor vincristine or colchicine, but not the microtubule depolymerisation inhibitor paclitaxel, provoked a lethal synergistic effect. CONCLUSION: PLK1 inhibition together with microtubule-targeting chemicals, serve as a potent therapeutic strategy for targeting tetraploid cancer cells.
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Apoptosis/efectos de los fármacos , Proteínas de Ciclo Celular/antagonistas & inhibidores , Neoplasias del Colon/tratamiento farmacológico , Mitosis/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Pteridinas/toxicidad , Tetraploidía , Antimitóticos/farmacología , Antimitóticos/toxicidad , Antineoplásicos Fitogénicos/farmacología , Ciclo Celular/efectos de los fármacos , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Colchicina/farmacología , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Sinergismo Farmacológico , Humanos , Microtúbulos/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Paclitaxel/farmacología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Pteridinas/farmacología , ARN Interferente Pequeño , Moduladores de Tubulina/farmacología , Vincristina/farmacología , Quinasa Tipo Polo 1RESUMEN
Many signaling pathways involved in bone homeostasis also participate in the anabolic response of bone to mechanical loading. For example, TGFß signaling coordinates the maintenance of bone mass and bone quality through its effects on osteoblasts, osteoclasts, and osteocytes. TGFß signaling is also essential for the mechanosensitive formation of new bone. However, the mechanosensitive mechanisms controlling TGFß signaling in osteocytes remain to be determined, particularly those that integrate TGFß signaling with other early responses to mechanical stimulation. Here, we used an in vivo mouse hindlimb loading model to identify mechanosensitive molecules in the TGFß pathway, and MLO-Y4 cells to evaluate their interactions with the prostaglandin E2 (PGE2) pathway, which is well-known for its rapid response to mechanical stimulation and its role in bone anabolism. Although mRNA levels for several TGFß ligands, receptors, and effectors were unchanged, the level of phosphorylated Smad2/3 (pSmad2/3) was reduced in tibial bone as early as 3â¯h after early mechanical stimulation. We found that PGE2 and its receptor, EP2, repress pSmad2/3 levels and transactivation of Serpine1 in osteocytes. PGE2 and EP2 control the level of pSmad2/3 through a proteasome-dependent mechanism that relies on the deubiquitinase CYLD. CYLD protein levels were also reduced in the tibiae within 3â¯h of mechanical loading. Using CYLD-deficient mice, we found that CYLD is required for the rapid load-mediated repression of pSmad2/3 and for load-induced bone formation. These data introduce CYLD as a mechanosensitive deubiquitinase that participates in the prostaglandin-dependent repression of TGFß signaling in osteocytes.