Biology subjects

Bragado, P.

Publications and source records attributed to Bragado, P..

5 recordsLinked to original sources

bioRxiv2025

CRISPR screening reveals SYCP3 as a key driver of metastasis in prostate cancer

Prostate cancer (PCa) is a prevalent male cancer with high survival rates, except in advanced or metastatic stages, for which effective treatments are lacking. Metastatic PCa involves complex mechanisms including loss of tumor suppressor genes and DNA repair molecules, which impacts therapy responses. We have reanalyzed data from a CRISPR/Cas9 genome wide screening previously performed to identify essential regulators of invasive abilities of the metastatic cell line DU145 identifying SYCP3 as a regulator of metastatic invasion. Subsequent analyses of tumor samples demonstrated that SYCP3 expression is frequently upregulated in PCa tumors from patients in advanced stages. Furthermore, SYCP3 genetic depletion significantly reduced the invasive and migratory abilities of DU145 cells and increased their adhesion capacity. Additionally, and due to the implication of SYCP3 on DNA repair processes, we have analyzed the role of SYCP3 on the cellular response to radiotherapy (RT) and found that its depletion induced RT resistance, suggesting a role for SYCP3 in DNA damage response and genomic instability. All these data support a role for SYCP3 in PCa metastasis and provides opportunities for personalized medicine.

cancer biology↗

bioRxiv2024

Purinergic Receptor P2Y13 Controls Activation and Mode of Division in Subependymal Adult Neural Stem Cells

The subependymal zone (SEZ) of the mammalian brain is the most active germinal area that continues to generate newborn neurons throughout life. This area harbors a population of neural stem cells (NSCs) that can be found in different states of activation, each differing in proliferative capacity and molecular signature: quiescent NSCs (qNSCs), primed NSCs (pNSCs), and activated NSCs (aNSCs). There is currently a void in terms of the specific markers available to effectively discern between these transient states. Likewise, the molecular signaling mechanisms controlling the transition from quiescence to activation remain largely unexplored, as do the factors influencing the decision between differentiation and self-renewal during NSC division. Here, we present evidence that the metabotropic P2Y13 purinergic receptor plays a critical role in regulating adult neurogenesis. We found that P2Y13 is specifically expressed in NSCs within the adult SEZ and that its levels can be used to distinguish qNSCs from aNSCs. Functionally, P2Y13 signaling promotes NSC activation, enhancing lineage progression, while dampening their self-renewal capacity. Conversely, pharmacological blockade or genetic silencing of the P2Y13 receptor favors NSC quiescence. Thus, we identified the metabotropic P2Y13 purinergic receptor as a pivotal modulator of NSC dynamics, influencing both the balance between NSC quiescence and activation and the mode of NSC division at the subependymal zone.

neuroscience↗

bioRxiv2024

In vitro FLASH irradiation of A549 lung cancer cells and IMR90 healthy human fibroblasts in the synchrocyclotron room of a clinical proton therapy system

PurposeThis study aims to investigate the FLASH irradiation effect on lung tumor (A549) and healthy fibroblast (IMR90) cell lines using an irradiation station installed at the synchrocyclotron room of a clinical proton facility without any permanent beamline modifications. Methods and MaterialsAn irradiation system composed of a lead scatterer and 3D-printed positioning system was designed and fabricated to operate within the beamline gap of the IBA Proteus One proton therapy facility after the extraction of the beam from the synchrocyclotron. A dosimetric analysis of the produced irradiation field was carried out using radiochromic films. FLASH and conventional-rate irradiations were conducted on relevant cell lines for lung cancer at the isocenter of the treatment room. Biological assessments post-irradiation included clonogenic and viability assays for cell survival, immunofluorescence analysis of p21 protein expression, and flow cytometry analysis for cell cycle arrest evaluation. ResultsThe irradiation system successfully delivered homogeneous and repeatable FLASH dose rates (>900 Gy/s) with a positioning accuracy of 1 mm and dose uniformity within 10%. Clonogenic assays revealed no statistically significant differences in survival between FLASH and conventional dose rates for both A549 and IMR90 cell lines, although a trend towards higher viability was observed in IMR90 cells under FLASH conditions. Flow cytometry demonstrated significant differences in cell cycle arrest patterns at doses above 7 Gy, with FLASH-irradiated cells exhibiting a decrease in G2/M phase arrest compared to conventional rates. Immunofluorescence analysis of p21 expression showed no significant differences between irradiation modalities. ConclusionsThe developed irradiation station effectively facilitates FLASH radiotherapy experiments in a clinical proton facility, achieving the necessary dose rates without hardware modification or extra tuning of the facility. Our analysis reported notable alterations in cell cycle dynamics suggesting distinct biological responses between FLASH and conventional rates in both healthy and tumor cells. These findings contribute to the emerging understanding of the FLASH effect and support the potential for its differential impact on cancerous versus healthy tissues.

bioengineering↗

bioRxiv2023

CRISPR/Cas9 screenings unearth protein arginine methyltransferase 7 as a novel driver of metastasis in prostate cancer

Owing to the inefficacy of available treatments, the survival rate of patients with metastatic prostate cancer (mPCa) is severely decreased. Therefore, it is crucial to identify new therapeutic targets to increase their survival. This study aim was to identify the most relevant regulators of mPCa onset by performing two high-throughput CRISPR/Cas9 screenings. Furthermore, some of the top hits were validated using small interfering RNA (siRNA) technology, with protein arginine methyltransferase 7 (PRMT7) being the best candidate. Its inhibition or depletion via CRISPR significantly reduced mPCa cell capacities in vitro. Moreover, PRMT7 ablation reduced mPCa appearance in chicken chorioallantoic membrane and mouse xenograft assays. Molecularly, PRMT7 reprograms the expression of several adhesion molecules through methylation of several transcription factors, such as FoxK1 or NR1H2, which results in primary tumor PCa cell adhesion loss and motility gain. Importantly, PRMT7 is upregulated in advanced stages of Spanish PCa tumor samples and PRMT7 pharmacological inhibition reduces the dissemination of mPCa cells. Thus, here is shown that PRMT7 is a potential therapeutic target and biomarker of mPCa.

cancer biology↗

bioRxiv2020

Myeloid derived Oncostatin M reprogrammes cancer-associated fibroblasts and tumour cells promoting breast cancer progression

Cancer cells are constantly communicating with the surrounding tumour microenvironment (TME) and they hijack physiological cell interactions to overcome immune system surveillance and promote cancer progression1,2. However, the contribution of stromal cells to the reprogramming of the TME is not well understood. In this study we provide unprecedented evidence of the role of the cytokine Oncostatin M (OSM) as central node for multicellular interactions between immune and non-immune stroma and the epithelial compartment. We show that stromal expression of the OSM:Oncostatin M Receptor (OSMR) axis plays a key role in breast cancer progression. OSMR deletion in a multistage breast cancer model delays tumour onset, tumour growth and reduces metastatic burden. We ascribed causality to the stromal function of OSM axis by demonstrating reduced tumour burden of syngeneic tumours implanted in mice. Single-cell and bioinformatic analysis of murine and human breast tumours revealed that the expression of OSM signalling components is compartmentalized in the tumour stroma. OSM expression is restricted to myeloid cells, whereas OSMR expression is detected predominantly in fibroblasts and, to a lower extent, cancer cells. Myeloid-derived OSM reprograms fibroblasts to a more contractile and pro-tumorigenic phenotype, elicits the secretion of VEGF and pro-inflammatory chemokines (e.g. CXCL1 and CXCL16), leading to increased neutrophil and macrophage recruitment. In summary, our work sheds light on the mechanism of immune regulation by the tumour microenvironment, and supports that targeting OSM:OSMR interactions is a potential therapeutic strategy to inhibit tumour-promoting inflammation and breast cancer progression.

cancer biology↗