Biology subjects

Munoz-Galvan, S.

Publications and source records attributed to Munoz-Galvan, S..

3 recordsLinked to original sources

bioRxiv2023

Essential role of PLD2 in hypoxia-induced stemness and therapy resistance in ovarian tumors

Hypoxia in solid tumors is a source of chemoresistance that determines poor patient prognosis and relies on the presence of cancer stem cells (CSCs). Here we use ovarian cancer (OC) as a model and a combination of 2D and 3D cell cultures, xenograft models, patient samples, transcriptional databases, iPSCs and ATAC-seq, to address the mechanisms leading to hypoxia-induced CSC generation and chemoresistance. We show that hypoxia activates the expression of the PLD2 gene encoding phospholipase D2. PLD2 overexpression leads to increased CSC-like features, similar to hypoxia, while PLD2 depletion in hypoxia partially suppresses these effects, indicating a role of PLD2 in hypoxia-induced CSC generation in OC. Finally, PLD2 overexpression provokes chemoresistance that is suppressed by combination treatment with PLD2 inhibition. Altogether, our work highlights the HIF-1D-PLD2 axis in hypoxia-induced CSC generation and chemoresistance in OC and proposes an alternative treatment for patients with high PLD2 expression. Statement of SignificanceHypoxia in solid tumors is a major source of chemoresistance and cancer stem cells. We show that hypoxia-induced stemness is mediated by phospholipase D2 in ovarian tumors, generating therapy resistance that is overcome by phospholipase D inhibition. Therefore, we propose an alternative treatment for patients with high PLD2 expression.

cancer biology↗

bioRxiv2023

A 3D microtumour system that faithfully represents ovarian cancer minimal residual disease

BackgroundBulk cancer and minimal residual disease (MRD) are characterised by different molecular drivers and therefore necessitate different therapeutic strategies. However, there are currently no 3D models that can faithfully recapitulate MRD ex vivo for therapy development. MethodsA microfluidic technique was implemented to construct 3D microtumours, in which tumour cells, either by themselves or with fibroblasts, were encapsulated in viscous hydrogels. The 3D microtumours were analysed for their response to first-line chemotherapeutics and characterised through RNA-Seq, by comparing them to both 2D cultures and clinical samples. ResultsOur microfluidic platform guarantees the fabrication of 3D microtumours of tailorable size and cell content, which recreate key features of tumours such as hypoxia, characteristic organization of the cytoskeleton and a dose-response to chemotherapeutics close to the physiological range. The 3D microtumours were also used to examine non-genetic heterogeneity in ovarian cancer and could fully reflect the recently described "Oxford Classic" five molecular signatures. The gene expression profile of 3D microtumours following chemotherapy treatment closely resembled that of MRD in ovarian cancer patients, showing the upregulation of genes involved in fatty acid metabolism. We demonstrate that these 3D microtumours are ideal for drug development by showing how they support the identification of a promising inhibitor of fatty acid oxidation, perhexiline, which specifically targets chemotherapy-resistant MRD ovarian cancer cells and not bulk cancer cells. ConclusionWe have obtained the first 3D model of ovarian cancer MRD by using microtumours generated through microfluidics. This system is ideal for high-throughput drug screening and, given its versatility, it can be readily extended to additional types of cancer, as well as accommodate multiple cell types to generate complex tumour microenvironments.

cancer biology↗

bioRxiv2021

Identification of a minimal biomarker profile in head-and-neck squamous cell carcinoma tumors

Although important advances have been made in the knowledge of the molecular mechanisms leading to the development, of head and neck squamous cell carcinoma (HNSCC), only PDL1 is used for the immunotherapy (pemborlizumab) treatment in the first line of metastatic or recurrent disease. There are no other molecular biomarkers currently used in clinical practice. The objective of the study was to identify transcriptional alterations in patients with oral cavity cancer that identify gene networks responsible for resistance to treatment and prognosis. To identify possible targets for the treatment or prevention of these tumors, we screened for changes in transcription of genes that were recurrently altered in patients and that successfully stratify tumoral and non-tumoral samples, as well as patient survival, based on expression levels. The gene panels are primarily related to the cell cycle, DNA damage response, cytokine signaling and the immune system but also to the embryonic stem cell core. Validation of these panels in an independent cohort led to the identification of three non-interconnected genes, WDR66, SERPINH1 and ZNF622, that can predict patient survival and are differentially expressed in 3D cultures from HNSCC primary cell lines. These genes are related to stemness phenotype are transcriptional targets of the pluripotency transcription factors Sox2 and c-Myc. Our results suggest that WDR66, SERPINH1 and ZNF622 con-stitute a minimal signature of stemness transcriptional targets able to predict the prognosis of HNSCC tumors. Simple SummaryThe objective of the study was to identify transcriptional alterations in patients with oral cavity cancer to possibly identify gene networks responsible for resistance to treatment and prognosis. We identify bioinformatically gene panels are primarily related to the cell cycle, DNA damage response, cytokine signaling and the immune system but also to the embryonic stem cell core. Validation of these panels in patients independent cohorts led to the identification of three non-interconnected genes, WDR66, SERPINHl and ZNF622, that can predict patient survival and are differentially expressed in cancer stem cells cultures from HNSCC. These genes are related to stemness phenotype and epithelial-to-mesenchymal transition and are transcriptional targets of the pluripotency transcription factors Sox2 and c-Myc.

cancer biology↗