A carregar...
Projeto de investigação
In vitro and in vivo studies of novel glycan-based anti-cancer Immunotherapy approaches
Financiador
Autores
Publicações
Sialyl LewisX/A and Cytokeratin Crosstalk in Triple Negative Breast Cancer
Publication . Pascoal, Carlota; Carrascal, Mylène A.; Barreira, Daniela F.; Lourenço, Rita A.; Granjo, Pedro; Grosso, Ana R.; Borralho, Paula; Braga, Sofia; Videira, Paula A.; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM); MDPI - Multidisciplinary Digital Publishing Institute
Triple-negative breast cancer (TNBC) encompasses multiple entities and is generally highly aggressive and metastatic. We aimed to determine the clinical and biological relevance of Sialyl-Lewis X and A (sLeX/A)—a fucosylated glycan involved in metastasis—in TNBC. Here, we studied tissues from 50 TNBC patients, transcripts from a TNBC dataset from The Cancer Genome Atlas (TCGA) database, and a primary breast cancer cell line. All 50 TNBC tissue samples analysed expressed sLeX/A. Patients with high expression of sLeX/A had 3 years less disease-free survival than patients with lower expression. In tissue, sLeX/A negatively correlated with cytokeratins 5/6 (CK5/6, which was corroborated by the inverse correlation between fucosyltransferases and CK5/6 genes. Our observations were confirmed in vitro when inhibition of sLeX/A remarkably increased expression of CK5/6, followed by a decreased proliferation and invasion capacity. Among the reported glycoproteins bearing sLeX/A and based on the STRING tool, α6 integrin showed the highest interaction score with CK5/6. This is the first report on the sLeX/A expression in TNBC, highlighting its association with lower disease-free survival and its inverse crosstalk with CK5/6 with α6 integrin as a mediator. All in all, sLeX/A is critical for TNBC malignancy and a potential prognosis biomarker and therapeutic target.
Unraveling the biological potential of skin fibroblast
Publication . Pascoal, Carlota; Granjo, Pedro; Mexia, Patrícia; Gallego, Diana; Lourenço, Rita Adubeiro; Sharma, Shally; Pérez, Bélen; Castro-Caldas, Margarida; Grosso, Ana Rita; Ferreira, Vanessa dos Reis; Videira, Paula Alexandra; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; Elsevier Science B.V., Amsterdam.
Objective: In this study, we examined the molecular response of human skin fibroblasts to an inflammatory cytokine to evaluate their suitability as models for immunopathology research. Methods: Skin fibroblasts were stimulated with tumour necrosis factor (TNF)-α, and the transcriptome was profiled via RNA-Seq. The differentially expressed genes were screened to predict immunological pathways and interactions. The cytokines and signaling pathways were validated at protein level. Similarly to immune cells, TNF-α caused transcriptional and transductional changes in fibroblasts. Results: Functional analysis revealed significant enrichment of TNF-α signaling and cell chemotaxis (normalized enrichment score = 2.59 and 3.42). We also detected enrichment of nuclear factor kappa B (NF-κB) target genes and NF-kB activation, confirmed by complete protein degradation of its inhibitor IκBa (p = 0.0019). The MAPK/ERK and p38 MAPK pathways were also activated. Finally, we observed significant secretion of proinflammatory cytokines and chemokines, such as interleukin 6 (p = 0.02), CXCL8 (p = 0.027), CCL2 (p = 0.028) and CCL5 (p = 0.016). Conclusion: This study advances the biological understanding of skin fibroblast responses to TNF-α, revealing their intracellular pathways and secretome. It discloses techniques for leveraging fibroblasts' potential as in vitro models to identify inflammatory drivers, particularly when alternative models are inaccessible.
Studying the role of glycan-based biomarkers in cancer : Towards prognostic and therapeutic applications
Publication . Lourenço, Rita Adubeiro; Videira, Paula Alexandra Quintela; Silva, Zélia Maria Cordeiro da; Sousa, Rui Pedro Romero Amandi
Glycosylation is a complex post-translational modification that impacts most proteins in the human body and is critical for several biological processes. Disruptions in glycosylation are often associated with diseases, particularly cancer, where altered glycan structures drive tumour development and progression. One key alteration is the increase in sialylated glycans like the abnormal sialyl-Tn (STn), typically absent in healthy tissues, making it a promising cancer biomarker and therapeutic target. However, the exact role of STn in cancer progression is still unclear and remains under active investigation.
This thesis aimed to clarify the role of STn in cancer, more specifically in triple-negative breast cancer (TNBC) and colorectal cancer (CRC). A systematic review of the literature revealed that STn is generally associated with poor survival. However, its prognostic value varies across cancer types and cohorts. Mucins, along with proteins like CD44 and beta 1 integrin (ITGB1), were identified as key carriers of STn in cancers, all of which are involved in tumour progression. In TNBC, only ~25 % of the cases express STn. This subgroup is associated with reduced survival and with an immunosuppressive environment. STn shows a negative association with the c-Myc, despite promoting higher cell proliferation in vitro. In CRC, STn expression is present in most cases and correlated with important molecular features such as microsatellite instability (MSI) and with glycosylation-related genes, such as the ST6GALNAC1 gene, which explains the expression of STn and correlated with the consensus molecular subtype 3 (CMS3).
Additionally, this work presents the development of an interactive platform integrating visualisation tools of glycomic and glycosylation-related transcriptomic data from cancer cell lines and tissues. It provides a tool to visually explore glycosylation traits, which significantly contributes to cancer glycosylation research and accelerates the identification of glycan-based biomarkers that can be used in the clinic.
Overall, this work's findings elucidate the impact of STn on cancer progression, rein-forcing its significant but complex role as a cancer biomarker for prognostic and targeted therapeutic purposes.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
OE
Número da atribuição
SFRH/BD/148480/2019