Publications by authors named "Mireia Vallespinos"

Article Synopsis
  • The study focuses on pancreatic ductal adenocarcinoma (PDAC) and how cancer stem cells (CSCs) contribute to its aggressive nature and resistance to therapies, particularly immune checkpoint inhibitors.
  • Researchers used a mouse model and primary tumor cell lines to identify CSC populations and their immune evasion strategies, discovering that the gene peptidoglycan recognition protein 1 (PGLYRP1) is significantly overexpressed in these cells.
  • The findings suggest PGLYRP1 plays a key role in helping CSCs evade immune responses, highlighting its potential as a new target for immunotherapy in PDAC patients.
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Background: Previous studies by our group have shown that oxidative phosphorylation (OXPHOS) is the main pathway by which pancreatic cancer stem cells (CSCs) meet their energetic requirements; therefore, OXPHOS represents an Achille's heel of these highly tumorigenic cells. Unfortunately, therapies that target OXPHOS in CSCs are lacking.

Methods: The safety and anti-CSC activity of a ruthenium complex featuring bipyridine and terpyridine ligands and one coordination labile position (Ru1) were evaluated across primary pancreatic cancer cultures and in vivo, using 8 patient-derived xenografts (PDXs).

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Objective: The lysyl oxidase-like protein 2 (LOXL2) contributes to tumour progression and metastasis in different tumour entities, but its role in pancreatic ductal adenocarcinoma (PDAC) has not been evaluated in immunocompetent in vivo PDAC models.

Design: Towards this end, we used PDAC patient data sets, patient-derived xenograft in vivo and in vitro models, and four conditional genetically-engineered mouse models (GEMMS) to dissect the role of LOXL2 in PDAC. For GEMM-based studies, ; ; mice (KPC) and the ; mice (KC) were crossed with allele floxed mice ( ) or conditional overexpressing mice (R26 ) to generate KPCL2 or KCL2 and KPCL2 or KCL2 mice, which were used to study overall survival; tumour incidence, burden and differentiation; metastases; epithelial to mesenchymal transition (EMT); stemness and extracellular collagen matrix (ECM) organisation.

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Background & Aims: The existence of different subtypes of pancreatic ductal adenocarcinoma (PDAC) and their correlation with patient outcome have shifted the emphasis on patient classification for better decision-making algorithms and personalized therapy. The contribution of mechanisms regulating the cancer stem cell (CSC) population in different subtypes remains unknown.

Methods: Using RNA-seq, we identified B-cell CLL/lymphoma 3 (BCL3), an atypical nf-κb signaling member, as differing in pancreatic CSCs.

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Pancreatic ductal adenocarcinoma (PDAC) is an inherently chemoresistant tumor. Chemotherapy leads to apoptosis of cancer cells, and in previous studies we have shown that tumor-associated macrophage (TAM) infiltration increases following chemotherapy in PDAC. Since one of the main functions of macrophages is to eliminate apoptotic cells, we hypothesized that TAMs phagocytose chemotherapy-induced apoptotic cells and secrete factors, which favor PDAC chemoresistance.

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Article Synopsis
  • - Pancreatic ductal adenocarcinoma (PDAC) features a significant amount of desmoplastic stroma primarily made up of cancer-associated fibroblasts (CAFs), which are believed to promote tumor growth and contribute to drug resistance and immune suppression.
  • - Researchers found that the gene Saa3, part of the serum amyloid A family, is significantly expressed in PDGFRα CAFs and is crucial in enhancing the tumor-promoting activity of these cells while its absence inhibits tumor growth.
  • - The study suggests that high levels of the human equivalent of Saa3 in CAFs correlate with poor survival outcomes in PDAC patients, indicating that targeting this gene could offer potential therapeutic strategies.
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The stromal microenvironment controls response to injury and inflammation, and is also an important determinant of cancer cell behavior. However, our understanding of its modulation by miRNA (miR) and their respective targets is still sparse. Here, we identified the miR-25-93-106b cluster and two new target genes as critical drivers for metastasis and immune evasion of cancer cells.

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Cancer stem cells (CSCs) are a unique subset of cells within tumors with stemlike properties that have been proposed to be key drivers of tumor initiation and progression. CSCs are functionally defined by their unlimited self-renewal capacity and their ability to initiate tumor formation in vivo. Like normal stem cells, CSCs exist in a cellular niche comprised of numerous cell types including tumor-associated macrophages (TAMs) which provides a unique microenvironment to protect and promote CSC functions.

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c-Myc, a member of the Myc family of transcription factors, is involved in numerous biological functions including the regulation of cell proliferation, differentiation, and apoptosis in various cell types. Of all of its functions, the role of c-Myc in cell differentiation is one of the least understood. We addressed the role of c-Myc in B lymphocyte differentiation.

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The c-Myc protein is a transcription factor implicated in the regulation of multiple biological processes, including cell proliferation, cell growth, and apoptosis. In vivo overexpression of c-myc is linked to tumor development in a number of mouse models. Here, we show that perinatal inactivation of c-Myc in liver causes disorganized organ architecture, decreased hepatocyte size, and cell ploidy.

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