Browsing by Author "Ortiz, Rina"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Publication Capture and detection of extracellular vesicles derived from human breast cancer cells using a 3D self-assembled nanostructured SiO2 microfluidic chip(2025) Cabeza, Carolina; Rojas, Felipe; Lobos, Lorena; Lemaitre, Dominique; Villena, Juan; Cordero, María; Hassan, Natalia; Ortiz, RinaBackground: Tumor-derived extracellular vesicles offer a minimally invasive approach to evaluate tumor progression and metastasis. However, detecting biomarkers, such as extracellular vesicles in body fluids during the early stages of disease, remains a significant challenge. Conventional methods like ultracentrifugation-based isolation or Western blot protein quantification are time-consuming, require large sample volumes, and offer low yield and sensitivity. Therefore, the development of new biosensors for the specific and efficient analysis of tumor extracellular vesicles is urgently needed. Methods: Microfluidic devices provide extraordinary benefits for bioanalysis, offering a large surface area for the contact between target molecules and the biosensor, significantly enhancing the specificity, efficiency, and speed. These devices also enable nanoscale and microscale work using reduced sample volumes. In this study, we developed a three-dimensional self-assembled SiO2-based nanostructured microfluidic chip, bioconjugated with specific antibodies targeting exosomal markers for the selective capture of CD63- and CD81-positive extracellular vesicles from breast cancer-derived conditioned cell culture media. Results: The three-dimensional SiO2-based microfluidic chip effectively captured extracellular vesicles expressing CD63 and CD81 antigens from breast cancer cell culture media. This evidence demonstrates the potential of this platform to detect extracellular vesicles as biomarkers for cancer, providing a specific and efficient, non-invasive approach for cancer diagnostics. Conclusions: This study highlights the potential application of three-dimensional SiO2-based microfluidic chips for detecting extracellular vesicles as a non-invasive liquid biopsy tool for breast cancer. The findings show a specific and efficient device as an alternative to conventional biomarker detection techniques.Item Src-family kinase inhibitors block early steps of caveolin-1-enhanced lungmetastasis by melanoma cells(2020) Ortiz, Rina; Díaz, Jorge; Díaz-Valdivia, Natalia; Martínez, Samuel; Simón, Layla; Contreras, Pamela; Lobos-González, Lorena; Guerrero, Simón; Leyton, Lisette; Quest, Andrew F.G.In advanced stages of cancer disease, caveolin-1 (CAV1) expression increases and correlates with increased migratory and invasive capacity of the respective tumor cells. Previous findings from our laboratory revealed that specific ECM-integrin interactions and tyrosine-14 phosphorylation of CAV1 are required for CAV1-enhanced melanoma cell migration, invasion and metastasis in vivo. In this context, CAV1 phosphorylation on tyrosine-14 mediated by non-receptor Src-family tyrosine kinases seems to be important; however, the effect of Src-family kinase inhibitors on CAV1-enhanced metastasis in vivo has not been studied. Here, we evaluated the effect of CAV1 and c-Abl overexpression, as well as the use of the Src-family kinase inhibitors, PP2 and dasatinib (more specific for Src/Abl) in lung metastasis of B16F10 melanoma cells. Overexpression of CAV1 and c-Abl enhanced CAV1 phosphorylation and the metastatic potential of the B16F10 murine melanoma cells. Alternatively, treatment with PP2 or dasatinib for 2 h reduced CAV1 tyrosine-14 phosphorylation and levels recovered fully within 12 h of removing the inhibitors. Nonetheless, pre-treatment of cells with these inhibitors for 2 h sufficed to prevent migration, invasion and trans-endothelial migration in vitro. Importantly, the transient decrease in CAV1 phosphorylation by these kinase inhibitors prevented early steps of CAV1-enhanced lung metastasis by B16F10 melanoma cells injected into the tail vein of mice. In conclusion, this study underscores the relevance of CAV1 tyrosine-14 phosphorylation by Src-family kinases during the first steps of the metastatic sequence promoted by CAV1. These findings open up potential options for treatment of metastatic tumors in patients in which Src-family kinase activation and CAV1 overexpression favor dissemination of cancer cells to secondary sites.