RESUMEN
Missense mutations in the TP53 tumor-suppressor gene inactivate its antitumorigenic properties and endow the incipient cells with newly acquired oncogenic properties that drive invasion and metastasis. Although the oncogenic effect of mutant p53 transcriptome has been widely acknowledged, the global influence of mutant p53 on cancer cell proteome remains to be fully elucidated. Here, we show that mutant p53 drives the release of invasive extracellular factors (the 'secretome') that facilitates the invasion of lung cancer cell lines. Proteomic characterization of the secretome from mutant p53-inducible H1299 human non-small cell lung cancer cell line discovered that the mutant p53 drives its oncogenic pathways through modulating the gene expression of numerous targets that are subsequently secreted from the cells. Of these genes, alpha-1 antitrypsin (A1AT) was identified as a critical effector of mutant p53 that drives invasion in vitro and in vivo, together with induction of epithelial-mesenchymal transition markers expression. Mutant p53 upregulated A1AT transcriptionally through the involvement with its family member p63. Conditioned medium containing secreted A1AT enhanced cell invasion, while an A1AT-blocking antibody attenuated the mutant p53-driven migration and invasion. Importantly, high A1AT expression correlated with increased tumor stage, elevated p53 staining and shorter overall survival in lung adenocarcinoma patients. Collectively, these findings suggest that A1AT is an indispensable target of mutant p53 with prognostic and therapeutic potential in mutant p53-expressing tumors.
Asunto(s)
Neoplasias Pulmonares/patología , Proteína p53 Supresora de Tumor/genética , alfa 1-Antitripsina/genética , Ciclo Celular , Línea Celular Tumoral , Movimiento Celular , Transición Epitelial-Mesenquimal , Humanos , Mutación , Invasividad Neoplásica , Proteómica , Proteína p53 Supresora de Tumor/fisiología , Regulación hacia ArribaRESUMEN
STUDY QUESTION: Are Sertoli cell tight junctions (TJs) disrupted in men undergoing hormonal contraception? SUMMARY ANSWER: Localization of the key Sertoli cell TJ protein, claudin-11, was markedly disrupted by 8 weeks of gonadotropin suppression, the degree of which was related to the extent of adluminal germ cell suppression. WHAT IS KNOWN ALREADY: Sertoli cell TJs are vital components of the blood-testis barrier (BTB) that sequester developing adluminal meiotic germ cells and spermatids from the vascular compartment. Claudin-11 knockout mice are infertile; additionally claudin-11 is spatially disrupted in chronically gonadotropin-suppressed rats coincident with a loss of BTB function, and claudin-11 is disorganized in various human testicular disorders. These data support the Sertoli cell TJ as a potential site of hormonal contraceptive action. STUDY DESIGN, SIZE, DURATION: BTB proteins were assessed by immunohistochemistry (n = 16 samples) and mRNA (n = 18 samples) expression levels in available archived testis tissue from a previous study of 22 men who had undergone 8 weeks of gonadotropin suppression and for whom meiotic and post-meiotic germ cell numbers were available. The gonadotropin suppression regimens were (i) testosterone enanthate (TE) plus the GnRH antagonist, acyline (A); (ii) TE + the progestin, levonorgestrel, (LNG); (iii) TE + LNG + A or (iv) TE + LNG + the 5α-reductase inhibitor, dutasteride (D). A control group consisted of seven additional men, with three archived samples available for this study. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Immunohistochemical localization of claudin-11 (TJ) and other junctional type markers [ZO-1 (cytoplasmic plaque), ß-catenin (adherens junction), connexin-43 (gap junction), vinculin (ectoplasmic specialization) and ß-actin (cytoskeleton)] and quantitative PCR was conducted using matched frozen testis tissue. MAIN RESULTS AND THE ROLE OF CHANCE: Claudin-11 formed a continuous staining pattern at the BTB in control men. Regardless of gonadotropin suppression treatment, claudin-11 localization was markedly disrupted and was broadly associated with the extent of meiotic/post-meiotic germ cell suppression; claudin-11 staining was (i) punctate (i.e. 'spotty' appearance) at the basal aspect of tubules when the average numbers of adluminal germ cells were <15% of control, (ii) presented as short fragments with cytoplasmic extensions when numbers were 15-25% of control or (iii) remained continuous when numbers were >40% of control. Changes in localization of connexin-43 and vinculin were also observed (smaller effects than for claudin-11) but ZO-1, ß-catenin and ß-actin did not differ, compared with control. LIMITATIONS, REASONS FOR CAUTION: Claudin-11 was the only Sertoli cell TJ protein investigated, but it is considered to be the most pivotal of constituent proteins given its known implication in infertility and BTB function. We were limited to testis samples which had been gonadotropin-suppressed for 8 weeks, shorter than the 74-day spermatogenic wave, which may account for the heterogeneity in claudin-11 and germ cell response observed among the men. Longer suppression (12-24 weeks) is known to suppress germ cells further and claudin-11 disruption may be more uniform, although we could not access such samples. WIDER IMPLICATIONS OF THE FINDINGS: These findings are important for our understanding of the sites of action of male hormonal contraception, because they suggest that BTB function could be ablated following long-term hormone suppression treatment. STUDY FUNDING/COMPETING INTERESTS: National Health and Medical Research Council (Australia) Program Grants 241000 and 494802; Research Fellowship 1022327 (to R.I.M.) and the Victorian Government's Operational Infrastructure Support Program. None of the authors have any conflicts to disclose. TRIAL REGISTRATION NUMBER: Not applicable.
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Claudinas/antagonistas & inhibidores , Anticonceptivos Masculinos/farmacología , Regulación hacia Abajo/efectos de los fármacos , Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Células de Sertoli/efectos de los fármacos , Uniones Estrechas/efectos de los fármacos , Inhibidores de 5-alfa-Reductasa/farmacología , Adulto , Andrógenos/farmacología , Barrera Hematotesticular/citología , Barrera Hematotesticular/efectos de los fármacos , Barrera Hematotesticular/metabolismo , Claudinas/genética , Claudinas/metabolismo , Dutasterida/farmacología , Humanos , Inmunohistoquímica , Levonorgestrel/farmacología , Masculino , Persona de Mediana Edad , Oligopéptidos/farmacología , Transporte de Proteínas/efectos de los fármacos , Reproducibilidad de los Resultados , Células de Sertoli/citología , Espermatogénesis/efectos de los fármacos , Testosterona/análogos & derivados , Testosterona/farmacología , Adulto JovenRESUMEN
SUMMARY: In this systematic review, we summarize risk factors for low bone mineral density and bone loss in healthy men age 50 years or older. Consistent risk factors were: age, smoking, low weight, physical/functional limitations, and previous fracture. Data specific to men has clinical and policy implications. INTRODUCTION: Osteoporosis is a significant health care problem in men as well as women, yet the majority of evidence on diagnosis and management of osteoporosis is focused on postmenopausal women. The objective of this systematic review is to examine risk factors for low bone mineral density (BMD) and bone loss in healthy men age 50 years or older. MATERIALS AND METHODS: A systematic search for observational studies was conducted in MEDLINE, Cochrane Database of Systematic Reviews, DARE, CENTRAL, CINAHL and Embase, Health STAR. The three main search concepts were bone density, densitometry, and risk factors. Trained reviewers assessed articles using a priori criteria. RESULTS: Of 642 screened abstracts, 299 articles required a full review, and 25 remained in the final assessment. Consistent risk factors for low BMD/bone loss were: advancing age, smoking, and low weight/weight loss. Although less evidence was available, physical/functional limitations and prevalent fracture (after age 50) were also associated with low BMD/bone loss. The evidence was inconsistent or weak for physical activity, alcohol consumption, calcium intake, muscle strength, family history of fracture/osteoporosis, and height/height loss. CONCLUSION: In this systematic review, we identified several risk factors for low BMD/bone loss in men that are measurable in primary practice.
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Osteoporosis/etiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Densidad Ósea , Fracturas Óseas/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Proyectos de Investigación , Factores de Riesgo , Fumar/efectos adversos , Pérdida de Peso/fisiologíaRESUMEN
BACKGROUND: A prospective study was performed to determine the most reliable MRI criteria to distinguish recurrent rectosigmoid carcinoma from benign postoperative fibrosis. METHODS: Twenty-two consecutive patients who were suspected to have recurrent rectosigmoid carcinoma were examined by T2 and precontrast and contrast enhanced T1 weighted images. The prospective interpretations, the presence of high signal on T2 weighted images, the shape of the margins of a mass and the degree of contrast enhancement were correlated with histology and follow up to determine their respective accuracies, sensitivities and specificities. RESULTS: The best criteria for recurrent tumor was the combination of high signal on T2 weighted images, round margins and > 40% contrast enhancement, which had an accuracy of 92%, sensitivity of 100% and specificity of 85%. In patients who were more than one year postoperative the specificity was 100%. CONCLUSIONS: The most reliable MRI criteria for distinguishing recurrent rectosigmoid carcinoma from benign postoperative fibrosis are the combination of the signal intensity on T2 weighed images, the shape of the margins of a mass and the presence of greater than 40% contrast enhancement.