Browsing by Author "Oliveira, Tiago"
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- Activation of RAC1/PAK1 axis potentiates transcriptional upregulation of DNA damage response genes via the BCL6/STAT5 switchPublication . Barros, Patrícia; Amaral, Andreia; Abrantes, Leonor; Oliveira, Tiago; Lourio, Henriqueta; Silva, Maria João; Jordan, Peter; Gama-Carvalho, Margarida; Matos, PauloColorectal cancer is one of the most prevalent types of cancer worldwide. The GTPase RAC1 and its effector PAK1 have been found overexpressed or hyperactivated in colorectal cancers, particularly those with more aggressive and invasive features, leading to unfavourable clinical prognosis, often resulting from chemoresistance.
- CCL2 expression predicts clinical outcomes and regulates E-cadherin and angiogenesis in pituitary tumoursPublication . Silva, Ana Luísa; Barry, Sayka; Lopes-Pinto, Mariana; Joaquim, Rita; Miranda, Catarina; Reis, Fábio; Miranda, Micaella; Matos, Paulo; Suleyman, Oniz; Oliveira, Tiago; López-Presa, Dolores; Borrecho, Gonçalo; Tortosa, Francisco; Faria, Claúdia C.; Korbonits, Márta; Marques, PedroThe crosstalk between tumour cells and microenvironment components in pituitary neuroendocrine tumours (PitNETs), including chemokines, may impact tumour behaviour and clinical outcomes. CCL2 was previously identified as a key chemokine in PitNETs, but its role remains unknown. We aimed to study the role of CCL2 in defining the phenotype and clinical outcomes of PitNETs and in regulating macrophage chemotaxis, epithelial-to-mesenchymal transition (EMT) and angiogenesis. We studied CCL2 and E-cadherin expression, macrophages (CD68 and CD163) and vessels (CD31) in samples from 86 PitNET patients. Higher CCL2 mRNA expression was found in patients who required multimodal and multiple treatments and had active disease at the last follow-up. Higher CCL2 immunoreactivity was observed in patients with larger PitNETs. Among somatotroph tumours, CCL2 mRNA expression correlated with serum IGF-1 at the last follow-up. CCL2 mRNA expression levels correlated negatively with CDH1 expression and with E-cadherin complete membranous staining. In vitro, CCL2 downregulated E-cadherin expression in GH3 cells but did not affect cell morphology or migration. CCL2 expression correlated with the number of vessels, vessel perimeter and vessel area in PitNETs but not with PitNET-infiltrating macrophages. Our data suggest that CCL2 may lead to (or is at least a predictive marker of) poorer clinical outcomes and more difficult-to-treat PitNETs, potentially through its regulatory effects on different tumour-related mechanisms beyond immune cell chemotaxis, including in the activation of the EMT pathway and modulation of angiogenesis in PitNETs. Further studies are needed to corroborate our findings and to validate CCL2 as a potential predictive marker and therapeutic target in PitNETs.
- Stimulation of RAC1/PAK1 signalling upregulates DNA damage repair genes via STAT5 stimulation of BCL6 repressed lociPublication . Barros, Patrícia; Amaral, Andreia; Abrantes, Leonor; Oliveira, Tiago; Louro, Henriqueta; Silva, Maria João; Jordan, Peter; Gama-Carvalho, Margarida; Matos, PauloColorectal cancer is one of the most prevalent types of cancer worldwide. The GTPase RAC1 and its effector PAK1 have been found overexpressed or hyperactivated in colorectal cancers, particularly those with more aggressive and invasive features, leading to unfavourable clinical prognosis, often resulting from chemoresistance.
- Stimulation of RAC1/PAK1 signalling upregulates DNA damage repair genes via STAT5 stimulation of BCL6 repressed lociPublication . Barros, Patricia; Amaral, Andreia; Abrantes, Leonor; Oliveira, Tiago; Louro, Henriqueta; Silva, Maria joão; Jordan, Peter; Gama-Carvalho, Margarida; Matos, PauloColorectal cancer is one of the most prevalent types of cancer worldwide. The GTPase RAC1 and its effector PAK1 have been found overexpressed or hyperactivated in colorectal cancers, particularly those with more aggressive and invasive features, leading to unfavourable clinical prognosis, often resulting from chemoresistance.
- Stimulation of RAC1/PAK1 signalling upregulates DNA damage repair genes via the BCL6/STAT5-switchPublication . Barros, Patrícia; Amaral, Andreia; Abrantes, Leonor; Oliveira, Tiago; Louro, Henriqueta; Silva, Maria João; Jordan, Peter; Gama-Carvalho, Margarida; Matos, PauloColorectal cancer is one of the most prevalent types of cancer worldwide. The GTPase RAC1 and its effector PAK1 have been found overexpressed or hyperactivated in colorectal cancers, particularly those with more aggressive and invasive features, leading to unfavourable clinical prognosis, often resulting from chemoresistance.
- Upregulation of RAC1/PAK1 signalling promotes DNA damage repair in colorectal cancer cellsPublication . Barros, Patricia; Amaral, Andreia; Abrantes, Leonor; Oliveira, Tiago; Louro, Henriqueta; Silva, Maria Joâo; Jordan, Peter; Gama Carvalho, Margarida; Matos, PauloIntroduction: Colorectal cancer is one of the most prevalent types of cancer worldwide. The GTPase RAC1 and its effector PAK1 have been found overexpressed or hyperactivated in this type of cancers, particularly those with more aggressive and invasive features, which is frequently correlated with resistance to chemotherapeutics and unfavourable clinical prognosis. Previously, we described a new signalling pathway in which activation of RAC1/PAK1 signalling promotes a transcriptional switch between the BCL6 repressor and the STAT5 transcriptional activator at a restricted subset of gene promoters.