Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) have therapeutic potential in the treatment of several immune disorders, including ulcerative colitis, owing to their ...regenerative and immunosuppressive properties. We recently showed that MSCs engineered to overexpress hypoxia-inducible factor 1-alpha and telomerase (MSC-T-HIF) and conditioned with pro-inflammatory stimuli release EVs (EV
) with potent immunomodulatory activity. We tested the efficacy of EV
to repolarize M1 macrophages (Mφ1) to M2-like macrophages (Mφ2-like) by analyzing surface markers and cytokines and performing functional assays in co-culture, including efferocytosis and T-cell proliferation. We also studied the capacity of EV
to dampen the inflammatory response of activated endothelium and modulate fibrosis. Finally, we tested the therapeutic capacity of EV
in an acute colitis model. EV
induced the repolarization of monocytes from Mφ1 to an Mφ2-like phenotype, which was accompanied by reduced inflammatory cytokine release. EV
-treated Mφ1 had similar effects of immunosuppression on activated peripheral blood mononuclear cells (PBMC) as Mφ2, and reduced the adhesion of PBMCs to activated endothelium. EV
also prevented myofibroblast differentiation of TGF-β-treated fibroblasts. Finally, administration of EV
promoted healing in a TNBS-induced mouse colitis model in terms of preserving colon length and intestinal mucosa architecture and altering the ratio of Mφ1/ Mφ2 infiltration. In conclusion, EV
have effective anti-inflammatory properties, making them potential therapeutic agents in cell free-based therapies for the treatment of Crohn's disease and likely other immune-mediated inflammatory diseases.
Abemaciclib is an ATP-competitive, reversible kinase inhibitor selective for CDK4 and CDK6 that has shown antitumor activity as a single agent in hormone receptor positive (HR+) metastatic breast ...cancer in clinical trials. Here, we examined the mechanistic effects of abemaciclib treatment using
and
breast cancer models. Treatment of estrogen receptor positive (ER+) breast cancer cells with abemaciclib alone led to a decrease in phosphorylation of Rb, arrest at G1, and a decrease in cell proliferation. Moreover, abemaciclib exposure led to durable inhibition of pRb, TopoIIα expression and DNA synthesis, which were maintained after drug removal. Treatment of ER+ breast cancer cells also led to a senescence response as indicated by accumulation of β-galactosidase, formation of senescence-associated heterochromatin foci, and a decrease in FOXM1 positive cells. Continuous exposure to abemaciclib altered breast cancer cell metabolism and induced apoptosis. In a xenograft model of ER+ breast cancer, abemaciclib monotherapy caused regression of tumor growth. Overall these data indicate that abemaciclib is a CDK4 and CDK6 inhibitor that, as a single agent, blocks breast cancer cell progression, and upon longer treatment can lead to sustained antitumor effects through the induction of senescence, apoptosis, and alteration of cellular metabolism.
Despite the strong evidence for the immunomodulatory activity of mesenchymal stromal cells (MSCs), clinical trials have so far failed to clearly show benefit, likely reflecting methodological ...shortcomings and lack of standardization. MSC-mediated tissue repair is commonly believed to occur in a paracrine manner, and it has been stated that extracellular vesicles (EVs) secreted by MSCs (EVMSC) are able to recapitulate the immunosuppressive properties of parental cells. As a next step, clinical trials to corroborate preclinical studies should be performed. However, effective dose in large mammals, including humans, is quite high and EVs industrial production is hindered by the proliferative senescence that affects MSCs during massive cell expansion. We generated a genetically modified MSC cell line overexpressing hypoxia-inducible factor 1-alpha and telomerase to increase the therapeutic potency of EVMSC and facilitate their large-scale production. We also developed a cytokine-based preconditioning culture medium to prime the immunomodulatory response of secreted EVs (EV
). We tested the efficacy of this system in vitro and in a delayed-type hypersensitivity mouse model. MSC-T with an HIF-1α-GFP lentiviral vector (MSC-T-HIF) can be effectively expanded to obtain large amounts of EVs without major changes in cell phenotype and EVs composition. EV
suppressed the proliferation of activated T-cells more effectively than did EVs from unmodified MSC in vitro, and significantly blunted the ear-swelling response in vivo by inhibiting cell infiltration and improving tissue integrity. We have developed a long-lived EV source that secretes high quantities of immunosuppressive EVs, facilitating a more standard and cost-effective therapeutic product.
Despite the biological and therapeutic relevance of CDK4/6 for the treatment of HR+, HER2- advanced breast cancer, the detailed mode of action of CDK4/6 inhibitors is not completely understood. Of ...particular interest, phosphorylation of CDK4 at T172 (pT172) is critical for generating the active conformation, yet no such crystal structure has been reported to date. We describe here the x-ray structure of active CDK4-cyclin D3 bound to the CDK4/6 inhibitor abemaciclib and discuss the key aspects of the catalytically-competent complex. Furthermore, the effect of CDK4/6 inhibitors on CDK4 T172 phosphorylation has not been explored, despite its role as a potential biomarker of CDK4/6 inhibitor response. We show mechanistically that CDK4/6i stabilize primed (pT172) CDK4-cyclin D complex and selectively displace p21 in responsive tumor cells. Stabilization of active CDK4-cyclin D1 complex can lead to pathway reactivation following alternate dosing regimen. Consequently, sustained binding of abemaciclib to CDK4 leads to potent cell cycle inhibition in breast cancer cell lines and prevents rebound activation of downstream signaling. Overall, our study provides key insights demonstrating that prolonged treatment with CDK4/6 inhibitors and composition of the CDK4/6-cyclin D complex are both critical determinants of abemaciclib efficacy, with implications for this class of anticancer therapy.
Background: People over 65 are the ones who have higher levels of functional limitations. There are many instruments to measure mobility in this age range that causes a lack of international ...consensus on what are the most suitable for this purpose. The aim is to analyze and identify which instruments provide greater data reliability and validity in measuring mobility in elderly people. Methods: Systematic review of the instruments used to measure mobility in people over 65 years published between 2001-2013, conducted in PubMed and Science Direct. Results: The 34 items selected instruments were grouped into 4 categories: doubly labeled water (DLW), motion detectors, objective measures of mobility and questionnaires. We identified, 23 are questionnaires, 4 accelerometers, 3 to objective measures of mobility and 2 both pedometers as DLW. The other 2 to combined analysis of different instruments. Conclusions: We conclude that assessing objective and subjective data obtains the most accurate measures of mobility. To obtain objective data, objective measures of mobility will be opposed to pedometers and accelerometers, while questionnaires were selected for subjective data due to its ease of use and sociodemographic data that provides. Among these instruments, the Short Physical Performance Battery (SPPB) and Minnesota Leisure Time are the most appropriate instruments to estimate the mobility of the elderly in Spain.
Fundamentos: Las personas mayores de 65 años son quienes presentan diferentes niveles de limitaciones funcionales. Existen múltiples instrumentos de medición de la movilidad en este grupo de edad y una falta de consenso internacional sobre cuáles son los más idóneos. El objetivo fue describir los instrumentos de medición de la movilidad en personas mayores de 65 años, determinar sus ventajas y limitaciones y comparar las características de validez de cada instrumento para poder establecer cuáles son los más válidos para este fin. Métodos: Revisión sistemática de la bibliografía sobre instrumentos utilizados para medir la movilidad en personas mayores de 65 años publicados entre 2001 a 2013. La búsqueda se realizó en las bases de datos Pubmed y Science Direct. Resultados: Los 34 artículos seleccionados permitieron agrupar los instrumentos en 4 grupos: agua doblemente marcada (DLW), detectores de movimiento, medidas objetivas de la movilidad y cuestionarios. Del total de artículos, 23 correspondieron a cuestionarios, 4 fueron sobre acelerómetros, 3 sobre medidas objetivas de la movilidad y 2 tanto sobre podómetros como DLW. Los otros 2 hacían referencia al análisis combinado de diferentes instrumentos. Conclusiones: Las medidas de movilidad más precisas se obtienen evaluando datos objetivos y subjetivos. Para obtener datos objetivos se usan las medidas objetivas de la movilidad frente a podómetros y acelerómetros, mientras que los cuestionarios son utilizados para obtener datos subjetivos debido a su facilidad de uso y a los datos sociodemográficos que aportan. Entre los instrumentos, el Short Physical Performance Battery (SPPB) y el Minesotta Leisure Time resultan los instrumentos más idóneos para medir la movilidad de las personas mayores en España.
El sol y la salud son términos que siempre han ido de la mano, pero no por eso es totalmente cierto que las radiaciones solares sean siempre saludables. Son indiscutibles los beneficios que el sol ...nos brinda, e imprescindibles para el mantenimiento y desarrollo de la vida tal y como la comprendemos; pero si la insolación de radiaciones ultravioletas (UV) e infrarrojos (IR) es elevada surgirán, a la larga, problemas de salud. Esta situación se complica extraordinariamente si aparece el "síndrome de tanorexia". Hallaremos entonces problemas y patologías incluso graves, tanto físicas como psíquicas, que afectarán también a las actividades sociales. Esta situación, si bien hasta ahora sólo se observaba en personas jóvenes, comienza a aparecer, en número creciente, en edades avanzadas de la vida, aumentando así los problemas de salud integral.
Most cancers preserve functional retinoblastoma (Rb) and may, therefore, respond to inhibition of D-cyclin-dependent Rb kinases, CDK4 and CDK6. To date, CDK4/6 inhibitors have shown promising ...clinical activity in breast cancer and lymphomas, but it is not clear which additional Rb-positive cancers might benefit from these agents. No systematic survey to compare relative sensitivities across tumor types and define molecular determinants of response has been described. We report a subset of cancers highly sensitive to CDK4/6 inhibition and characterized by various genomic aberrations known to elevate D-cyclin levels and describe a recurrent CCND1 3′UTR mutation associated with increased expression in endometrial cancer. The results suggest multiple additional classes of cancer that may benefit from CDK4/6-inhibiting drugs such as abemaciclib.
•A wide range of sensitivity to abemaciclib is observed among Rb+ tumor cells•CDKN2A mutant cancers show only intermediate sensitivity to CDK4/6 inhibition•D-cyclin activating features are associated with highly sensitive cells•About 5% of endometrial cancers bear a stabilizing mutation in the CCND1 3′UTR
Gong et al. identify a subset of cancers highly sensitive to CDK4/6 inhibition, which are characterized by various genomic aberrations known to elevate D-cyclin levels but not by CDKN2A mutations. They also identify a recurrent CCND1 3′UTR mutation associated with increased CCND1 expression in endometrial cancer.
Loss-of-function mutations in the retinoblastoma gene
are common in several treatment-refractory cancers such as small-cell lung cancer and triple-negative breast cancer. To identify drugs synthetic ...lethal with
mutation (
), we tested 36 cell-cycle inhibitors using a cancer cell panel profiling approach optimized to discern cytotoxic from cytostatic effects. Inhibitors of the Aurora kinases AURKA and AURKB showed the strongest
association in this assay. LY3295668, an AURKA inhibitor with over 1,000-fold selectivity versus AURKB, is distinguished by minimal toxicity to bone marrow cells at concentrations active against
cancer cells and leads to durable regression of
tumor xenografts at exposures that are well tolerated in rodents. Genetic suppression screens identified enforcers of the spindle-assembly checkpoint (SAC) as essential for LY3295668 cytotoxicity in RB1-deficient cancers and suggest a model in which a primed SAC creates a unique dependency on AURKA for mitotic exit and survival. SIGNIFICANCE: The identification of a synthetic lethal interaction between
and AURKA inhibition, and the discovery of a drug that can be dosed continuously to achieve uninterrupted inhibition of AURKA kinase activity without myelosuppression, suggest a new approach for the treatment of RB1-deficient malignancies, including patients progressing on CDK4/6 inhibitors.
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