29 documents found, page 1 of 3
Molecular profiling of prognostic biomarkers in Melanoma
Jesus, Marta; Correia, Beatriz; Costa, Catarina; João, Alexandre; Lopes, José Manuel; Barata, Catarina; Soares, Paula; Pópulo, HelenaCutaneous melanoma (CM) is the most aggressive and deadliest form of skin cancer (1). Its development is influenced by the genetic background, genetic mutations and environmental factors. The three most frequent mutations of CM appear in BRAF gene, which leads to uncontrolled cell growth, in NRAS gene, that disrupts normal cell signaling, and in TERT promoter, that increases telomerase activity and play a cruci...
Generation of an obese diabetic mouse model upon conditional Atrx disruption
Gaspar, Tiago Bordeira; Jesus, Tito Teles; Azevedo, Maria Teresa; Macedo, Sofia; Soares, Mariana Alves; Martins, Rui Sousa; Leite, Rúben; Rodrigues, LiaATRX mutations occur in up to 17% of human pancreatic neuroendocrine tumours (PanNETs), and recent evidence points towards its inability to drive PanNET formation in mouse pancreas while predisposing individuals to inflammageing. Aiming to explore the additional non-tumourigenic consequences of Atrx deletion, we characterised an aged series of Atrx conditional disruption in β cells using the Pdx1 promoter. Homo...
A 30-year long-term experience in appendix neuroendocrine neoplasms—granting a ...
Vinagre, João; Pinheiro, Jorge; Martinho, Olga; Reis, Rui Manuel; Preto, John; Soares, Paula; Lopes, José ManuelNeuroendocrine neoplasms (NENs) are the most common tumor of the appendix and have an excellent prognosis. Appendiceal tumors diagnosed between 1989 and 2019 were reviewed, and clinical data were collected from patient files. Part of the series was immuno-profiled for markers related to cell cycle proliferation and/or senescence-type, apoptotic, and metastatic potential. Appendix NENs were detected in 74 patien...
Histological Subtypes and Clinical Behavior Evaluation of Salivary Gland Tumors
Pinheiro, Jorge; Sá Fernandes, Margarida; Pereira, Ana Rodrigues; Lopes, José ManuelIntroduction: Salivary gland tumors include a wide spectrum of histological subtypes and clinical behavior, which we aim to evaluate.Material and Methods: We performed a retrospective study of all salivary gland tumors diagnosed and treated at the Centro Hospitalar São João, Porto, between 2005 and 2015. Histological re- evaluation was performed in all cases and patient files were reviewed and both clinical and...
TERT promoter mutations in pancreatic endocrine tumours are rare and mainly fou...
Vinagre, João; Nabais, Joana; Pinheiro, Jorge; Batista, Rui; Oliveira, Rui Caetano; Gonçalves, António Pedro; Pestana, Ana; Reis, MartaOne of the hallmarks of cancer is its unlimited replicative potential that needs a compensatory mechanism for the consequential telomere erosion. Telomerase promoter (TERTp) mutations were recently reported as a novel mechanism for telomerase re-activation/expression in order to maintain telomere length. Pancreatic endocrine tumors (PETs) were so far recognized to rely mainly on the alternative lengthening of t...
CUTANEOUS LUPUS ERYTHEMATOSUS - CLINICALPATHOLOGICAL CORRELATION OF LUPUS-SPECI...
Pedrosa, Ana; Lopes, José Manuel; Azevedo, FilomenaBackground: Lupus Erythematosus (LE) represents a multiorganic, autoimmune disease that affects mainly women of child-bearing age. The skin is the second most frequently affected organ, after the joints, and may precede the clinical onset of systemic symptoms.Objectives: To present the clinical findings which evoke the possibility of LE-specific skin lesions and the histopathological findings that may co-substa...
Telomerase promoter mutations in cancer: an emerging molecular biomarker?
Vinagre, João; Pinto, Vasco; Celestino, Ricardo; Reis, Marta; Populo, H; Boaventura, Paula; Melo, Miguel; Catarino, T.; Lima, Jorge; Lopes, José ManuelCell immortalization has been considered for a long time as a classic hallmark of cancer cells. Besides telomerase reactivation, such immortalization could be due to telomere maintenance through the “alternative mechanism of telomere lengthening” (ALT) but the mechanisms underlying both forms of reactivation remained elusive. Mutations in the coding region of telomerase gene are very rare in the cancer setting,...
Low frequency of TERT promoter mutations in gastrointestinal stromal tumors (GI...
Campanella, Natália C; Celestino, Ricardo; Pestana, Ana; Scapulatempo-Neto, C; Oliveira, Antonio Talvane de; Brito, Maria josé; Gouveia, AntónioSomatic mutations in the promoter region of telomerase reverse transcriptase (TERT) gene, mainly at positions c.-124 and c.-146 bp, are frequent in several human cancers; yet its presence in gastrointestinal stromal tumor (GIST) has not been reported to date. Herein, we searched for the presence and clinicopathological association of TERT promoter mutations in genomic DNA from 130 bona fide GISTs. We found TERT...
Frequency of TERT promoter mutations in human cancers
Vinagre, João; Almeida, Ana; Pópulo, Helena; Batista, Rui; Lyra, Joana; Pinto, Vasco; Coelho, Ricardo; Celestino, Ricardo; Prazeres, Hugo; Lima, LuísReactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechanisms remain poorly understood. Here we report the presence of recurrent somatic mutations in the TERT promoter in cancers of the central nervous system (43%), bladder (59%), thyroid (follicular cell-derived, 10%) and skin (melanoma, 29%). In thyroid cancers, the presence of TERT promoter mutations (when occurring tog...
Loss of WNK2 expression by promoter gene methylation occurs in adult gliomas an...
Moniz, Sónia; Martinho, Olga; Pinto, Filipe; Sousa, Bárbara; Loureiro, Cláudia; Oliveira, Maria José; Moita, Luís Ferreira; Honavar, MrinaliniThe gene encoding protein kinase WNK2 was recently identified to be silenced by promoter hypermethylation in gliomas and meningiomas, suggesting a tumour-suppressor role in these brain tumours. Following experimental depletion in cell lines, WNK2 was further found to control GTP-loading of Rac1, a signalling guanosine triphosphatase involved in cell migration and motility. Here we show that WNK2 promoter methyl...