Prognostic value of CtIP/RBBP8 expression in breast cancer

CtIP/RBBP8 is a multifunctional protein involved in transcription, DNA replication, DNA repair by homologous recombination and the G1 and G2 checkpoints. Its multiple roles are controlled by its interaction with several specific factors, including the tumor suppressor proteins BRCA1 and retinoblastoma. Both its functions and interactors point to a putative oncogenic potential of CtIP/RBBP8 loss. However, CtIP/RBBP8 relevance in breast tumor appearance, development, and prognosis has yet to be established. We performed a retrospective analysis of CtIP/RBBP8 and RB1 levels by immunohistochemistry using 384 paraffin-embedded breast cancer biopsies obtained during tumor removal surgery. We have observed that low or no expression of CtIP/RBBP8 correlates with high-grade breast cancer and with nodal metastasis. Reduction on CtIP/RBBP8 is most common in hormone receptor (HR)-negative, HER2-positive, and basal-like tumors. We observed lower levels of RB1 on those tumors with reduced CtIP/RBBP8 levels. On luminal tumors, decreased but not absence of CtIP/RBBP8 levels correlate with increased disease-free survival when treated with a combination of hormone, radio, and chemo therapies.España Ministerio de Economía y Competitividad SAF2010-14877Junta de Andalucía, Consejería de Salud AI2013-A-000

Creatividad para atender a la diversidad

Para construir una escuela inclusiva donde a cada alumno/a se le preste una adecuada atención a la diversidad, se necesita de una buena formación del profesorado, por ende, para enseñar de manera individualizada se requiere de unos adecuados conocimientos aptitudinales y actitudinales. Y en este caso concreto, pretendemos destacar dentro de la figura del maestro/a, su faceta creativa, es decir, como persona que se implica buscando soluciones ante nuevos retos y recurriendo a su ingenio para emprender nuevas situaciones. Por tanto, planteamos a la creatividad como herramienta que nos ayude a poder alcanzar una escuela para todos/as

Docentes para la inclusión educativa

En la presente comunicación se presentan aquellas competencias docentes que propician buenas prácticas educativas en relación a la inclusión, desde la perspectiva del profesorado. La metodología que se utilizó es la propia de un estudio descriptivo/comprensivo, de carácter exploratorio, donde mediante cuatro estudios de casos se analizan las percepciones de los profesionales de la educación de dos centros de educación secundaria, catalogados por la Administración Educativa Española como de “buenas prácticas”

Obatoclax and Paclitaxel Synergistically Induce Apoptosis and Overcome Paclitaxel Resistance in Urothelial Cancer Cells

Paclitaxel is a treatment option for advanced or metastatic bladder cancer after the failure of first-line cisplatin and gemcitabine, although resistance limits its clinical benefits. Mcl-1 is an anti-apoptotic protein that promotes resistance to paclitaxel in different tumors. Obatoclax, a BH3 mimetic of the Bcl-2 family of proteins, antagonizes Mcl-1 and hence may reverse paclitaxel resistance in Mcl-1-overexpressing tumors. In this study, paclitaxel-sensitive 5637 and -resistant HT1197 bladder cancer cells were treated with paclitaxel, obatoclax, or combinations of both. Apoptosis, cell cycle, and autophagy were measured by Western blot, flow cytometry, and fluorescence microscopy. Moreover, Mcl-1 expression was analyzed by immunohistochemistry in bladder carcinoma tissues. Our results confirmed that paclitaxel alone induced Mcl-1 downregulation and apoptosis in 5637, but not in HT1197 cells; however, combinations of obatoclax and paclitaxel sensitized HT1197 cells to the treatment. In obatoclax-treated 5637 and obatoclax + paclitaxel-treated HT1197 cells, the blockade of the autophagic flux correlated with apoptosis and was associated with caspase-dependent cleavage of beclin-1. Obatoclax alone delayed the cell cycle in 5637, but not in HT1197 cells, whereas combinations of both retarded the cell cycle and reduced mitotic slippage. In conclusion, obatoclax sensitizes HT1197 cells to paclitaxel-induced apoptosis through the blockade of the autophagic flux and effects on the cell cycle. Furthermore, Mcl-1 is overexpressed in many invasive bladder carcinomas, and it is related to tumor progression, so Mcl-1 expression may be of predictive value in bladder cancer.España, Sistema Público Andaluz Biobanco y ISCIII-Red de Biobancos PT17/0015/004

Both p62/SQSTM1-HDAC6-dependent autophagy and the aggresome pathway mediate CDK1 degradation in human breast cancer

Cyclin-dependent kinase 1 (CDK1) is the central mammalian regulator of cell proliferation and a promising therapeutic target for breast cancer. In fact, CDK1 inhibition downregulates survival and induces apoptosis. Due to its essential role, CDK1 expression and activity are strictly controlled at various levels. We previously described that CDK1 stability is also regulated and that SCF(βTrCP) ubiquitinates CDK1, which is degraded via the lysosomal pathway. In addition, in breast tumors from patients, we found a negative correlation between CDK1 accumulation and βTrCP levels, and a positive correlation with the degree of tumor malignancy. This prompted us to study the molecular mechanism involved in CDK1 clearance. In this report, we determine that both chemotherapeutic agents and proteolytic stress induce CDK1 degradation in human breast cancer MCF7 cells through p62/HDAC6-mediated selective autophagy. On the one hand, CDK1 binds to p62/SQSTM1-LC3 and, on the other hand, it interacts with HDAC6. Both complexes are dependent on the presence of an intact βTrCP-binding motif on CDK1. Furthermore, we also show that CDK1 is recruited to aggresomes in response to proteasome inhibition for an extended period. We propose CDK1 clearance as a potential predictive biomarker of antitumor treatment efficacy

E-cadherin expression is associated with somatostatin analogue response in acromegaly

Acromegaly is a rare disease resulting from hypersecretion of growth hormone (GH) and insulin‐like growth factor 1 (IGF1) typically caused by pituitary adenomas, which is associated with increased mortality and morbidity. Somatostatin analogues (SSAs) represent the primary medical therapy for acromegaly and are currently used as first‐line treatment or as second‐line therapy after unsuccessful pituitary surgery. However, a considerable proportion of patients do not adequately respond to SSAs treatment, and therefore, there is an urgent need to identify biomarkers predictors of response to SSAs. The aim of this study was to examine E‐cadherin expression by immunohistochemistry in fifty‐five GH‐producing pituitary tumours and determine the potential association with response to SSAs as well as other clinical and histopathological features. Acromegaly patients with tumours expressing low E‐cadherin levels exhibit a worse response to SSAs. E‐cadherin levels are associated with GH‐producing tumour histological subtypes. Our results indicate that the immunohistochemical detection of E‐cadherin might be useful in categorizing acromegaly patients based on the response to SSAs.ISCIII‐Subdirección General de Evaluación y Fomento de la Investigación PI13/02043 PI16/00175FEDER PI13/02043 PI16/00175Junta de Andalucía A‐0023‐2015 A‐0003‐2016 CTS‐1406 BIO‐0139Andalusian Ministry of Health C‐0015‐2014CIBERobn PI13/ 02043 PI16/0017

Prognostic significance of human pituitary tumor-transforming gene immunohistochemical expression in differentiated thyroid cancer

Context: Human securin pituitary tumor-transforming gene (hPTTG) is overexpressed in a variety of primary neoplasias, including differentiated thyroid cancer (DTC). Objective: The objective of this study was to examine the immunohistochemical expression of hPTTG in DTC and its association with known prognostic factors. Design: hPTTG expression was analyzed by immunostaining on paraffin-embedded tissues. Clinical data were used to determine any associations between the expression of hPTTG and prognostic variables of DTC. A median follow-up of 43 months allowed us to analyze the persistence of disease and the response to radioiodine therapy. Setting: The study was conducted at a tertiary university hospital. Patients: Ninety-five patients undergoing surgical resection for DTC (n = 60) or benign nodular thyroid disease (n = 35) were studied. Main Outcome Measure: The main outcome measure was the association between hPTTG expression and prognostic factors in DTC. Results: Among DTC cases, 21 (35%) had low and 39 (65%) had high hPTTG immunostaining. Adjacent nonneoplastic thyroid tissue was largely unstained. Among benign nodular thyroid disease cases, immunostaining was detected focally in eight (22.8%). A significant association was found between hPTTG expression and the presence of nodal (P < 0.01) or distant metastases (P < 0.05). A significant association with TNM was also found, because 83.3% of advanced TNM stages showed elevated hPTTG (P < 0.05). The association between hPTTG overexpression and decreased radioiodine uptake during follow-up was also significant (P < 0.05). The expression levels of hPTTG were confirmed as an independent prognostic factor for persistent disease (relative risk, 3.0; 95% confidence interval, 1.1-8.7; P < 0.05). Conclusions: Immunohistochemical analysis of hPTTG is of potential value in the determination of tumor aggressiveness in DTC.Peer Reviewe

Downregulation of protein tyrosine phosphatase PTPL1 alters cell cycle and upregulates invasion-related genes in prostate cancer cells

The final publication is available at link.springer.comPTPL1, a non-receptor type protein tyrosine phosphatase, has been involved in the regulation of apoptosis and invasiveness of various tumour cell types, but its role in prostate cancer remained to be investigated. We report here that downregulation of PTPL1 by small interfering RNA in PC3 cells decreases cell proliferation and concomitantly reduces the expression of cell cycle-related proteins such as cyclins E and B1, PCNA, PTTG1 and phospho-histone H3. PTPL1 downregulation also increases the invasion ability of PC3 cells through Matrigel coated membranes. cDNA array of PTPL1-silenced PC3 cells versus control cells showed an upregulation of invasion-related genes such as uPA, uPAR, tPA, PAI-1, integrin α6 and osteopontin. This increased expression was also confirmed in PTPL1-silenced DU145 prostate cancer cells by quantitative real time PCR and western blot. These findings suggest that PTPL1 is an important mediator of central cellular processes such as proliferation and invasion. © 2012 Springer Science+Business Media B.V.This work was supported by Grants from the Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Spain (FIS PI10/02026 and SAF2008-05046-C02-02), ISCIIIRETIC-RD06/0020-FEDER, Consejería de Salud (PI-2009-0589, AI-2010-003 to M.A.J.), and Consejería de Innovación, Ciencia y Empresa (CTS-6243), Junta de Andalucía (06/189, PI-2009-0589, and AI-2010-003 to M. A. J.). C. C. was supported by a pre-doctoral Grant from the Spanish Ministerio de Educación (F.P.I.: BES200612419) co-financiated by Fondo Social Europeo. C. S. was supported by a contract from Instituto de Salud Carlos III/FIS and Fundación Progreso y Salud, Consejería de Salud, Junta de Andalucía, Miguel Servet Program.Peer Reviewe

SCFFBXW7α modulates the intra-S-phase DNA-damage checkpoint by regulating Polo like kinase-1 stability

The intra-S-checkpoint is essential to control cell progression through S phase under normal conditions and in response to replication stress. When DNA lesions are detected, replication fork progression is blocked allowing time for repair to avoid genomic instability and the risk of cancer. DNA replication initiates at many origins of replication in eukaryotic cells, where a series of proteins form pre-replicative complexes (pre-RCs) that are activated to become pre-initiation complexes and ensure a single round of replication in each cell cycle. PLK1 plays an important role in the regulation of DNA replication, contributing to the regulation of pre-RCs formation by phosphorylating several proteins, under both normal and stress conditions. Here we report that PLK1 is ubiquitinated and degraded by SCFFBXW7α/proteasome. Moreover, we identified a new Cdc4 phosphodegron in PLK1, conserved from yeast to humans, whose mutation prevents PLK1 destruction. We established that endogenous SCFFBXW7α degrades PLK1 in the G1 and S phases of an unperturbed cell cycle and in S phase following UV irradiation. Furthermore, we showed that FBXW7α overexpression or UV irradiation prevented the loading of proteins onto chromatin to form pre-RCs and, accordingly, reduced cell proliferation. We conclude that PLK1 degradation mediated by SCFFBXW7α modulates the intra-S-phase checkpoint.Ministerio de Economía y Competitividad, MINECO SAF2011-30003Junta de Andalucía P08- CVI-0360

βTrCP controls the lysosome-mediated degradation of CDK1, whose accumulation correlates with tumor malignancy

n mammals, cell cycle progression is controlled by cyclin-dependent kinases, among which CDK1 plays important roles in the regulation of the G2/M transition, G1 progression and G1/S transition. CDK1 is highly regulated by its association to cyclins, phosphorylation and dephosphorylation, changes in subcellular localization, and by direct binding of CDK inhibitor proteins. CDK1 steady-state protein levels are held constant throughout the cell cycle by a coordinated regulation of protein synthesis and degradation. We show that CDK1 is ubiquitinated by the E3 ubiquitin ligase SCFβTrCP and degraded by the lysosome. Furthermore, we found that DNA damage not only triggers the stabilization of inhibitory phosphorylation sites on CDK1 and repression of CDK1 gene expression, but also regulates βTrCP-induced CDK1 degradation in a cell type-dependent manner. Specifically, treatment with the chemotherapeutic agent doxorubicin in certain cell lines provokes CDK1 degradation and induces apoptosis, whereas in others it inhibits destruction of the protein. These observations raise the possibility that different tumor types, depending on their pathogenic spectrum mutations, may display different sensitivity to βTrCP-induced CDK1 degradation after DNA damage. Finally, we found that CDK1 accumulation in patients’ tumors shows a negative correlation with βTrCP and a positive correlation with the degree of tumor malignancy.España, Ministerio de Economía y Competitividad SAF2011-30003Junta de Andalucía, Dirección General de Investigación, Tecnología y Empresa P08- CVI-03603 and P10-CTS-6243