Scognamiglio, Iolanda (2022) The relevance of exosomal microRNAs in the re-education of stromal fibroblasts: a framework for the comprehension of triple negative breast cancer. [Tesi di dottorato]


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Item Type: Tesi di dottorato
Resource language: English
Title: The relevance of exosomal microRNAs in the re-education of stromal fibroblasts: a framework for the comprehension of triple negative breast cancer
Date: 10 March 2022
Number of Pages: 78
Institution: Università degli Studi di Napoli Federico II
Department: Medicina Molecolare e Biotecnologie Mediche
Dottorato: Medicina molecolare e biotecnologie mediche
Ciclo di dottorato: 34
Coordinatore del Corso di dottorato:
Condorelli, GerolamaUNSPECIFIED
Date: 10 March 2022
Number of Pages: 78
Keywords: CAF; microRNA; Exosomes; TME; TNBC;
Settori scientifico-disciplinari del MIUR: Area 06 - Scienze mediche > MED/04 - Patologia generale
Date Deposited: 17 Mar 2022 15:11
Last Modified: 28 Feb 2024 10:35

Collection description

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, characterized by elevated metastatic potential. TNBC progression is strongly sustained by the recruitment of the tumor microenvironment (TME), mainly composed of Cancer-Associated Fibroblasts (CAFs) able to endorse tumor hallmarks. Increasing evidence demonstrated that exosomes mediate the crosstalk between cancer cells and TME through delivering their molecular cargo. In this thesis, we examined the role of TNBC cell-derived exosomes and their microRNAs (miRNAs) cargo in the activation of stromal fibroblasts towards CAFs. We demonstrated that TNBC cell-derived exosomes increased fibroblast-mediated collagen contraction ability and migration potential alongside CAF-related molecular markers. Furthermore, fibroblasts activated by exosomes promoted the invasion potential of normal breast epithelial cells as assessed by the three-dimensional organotypic co-culture assay which resembled the in vivo context. We further investigated the role of TNBC cell-derived exosomes cargo in activating normal fibroblasts, by performing a small RNA-sequencing on fibroblasts incubated with exosomes. The findings revealed multiple upregulated miRNAs in fibroblasts upon exosome incubation. Among these, miRNAs-185-5p, -652-5p, and -1246 (combo miRs) were found to synergistically boost fibroblast migration, invasion, and contraction abilities together with the related molecular markers, thus promoting a specific CAF sub-specialization towards a pro-migratory functional state rather than a proliferative phenotype. Furthermore, conditioned medium from stromal fibroblasts transfected with combo miRs (CM_combo miRs) induced the migration of non-tumorigenic epithelial breast MCF10A cells, as assessed by transwell assay and increased the proliferation of breast cancer MCF7 cells, and MCF10A cells, as tested by MTS assay. Moreover, we investigated the invasion ability of patient-derived breast cancer organoids when incubated with CM_combo miRs through the in vitro collagen invasion assay. We found wider invasive protrusions in organoids cultured with CM_combo miRs compared to control (CM_Scra) indicating an increased invading trend of cancer cells mediated by fibroblasts activated by exosomal miRs. All together these data highlighted the role of exosomes and their miRNA cargo in the re-education of fibroblasts within the TME, shedding light on processes related to triple negative breast cancer evolution.


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