Dipartimento di Farmacia e Scienze della Salute e della Nutrizione - Tesi di Dottorato
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Questa collezione raccoglie le Tesi di Dottorato afferenti al Dipartimento di Farmacia e Scienze della Salute e della Nutrizione dell'Università della Calabria.
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Item Novel molecular mechanisms involved in the stimulatory action of zinc in breast cancer(2016-11-22) Perri, Maria Grazia; Sisci, Diego; Maggiolini, MarcelloLo Zinco (Zn), minerale essenziale che regola diverse funzioni biologiche, è coinvolto nella progressione del tumore mammario. In particolare, è stato dimostrato che in seguito all’attivazione indotta dallo Zn di recettori ad attività tirosin-chinasica, come IGF-IR, EGFR e IR, vengono innescate vie di trasduzione del segnale che sono alla base della progressione tumorale, quali la via delle MAP-chinasi (MAPK) e la via del fosfatidilinositolo3-chinasi (PI3-K)/AKT. Numerosi studi hanno inoltre dimostrato il coinvolgimento di recettori accoppiati a proteina G (GPCRs) nello sviluppo dei tumori e la loro azione sinergica con vari recettori di membrana . Alla luce di tali osservazioni, una migliore comprensione dei processi attraverso cui i recettori per i fattori di crescita cooperano con segnali mediati da GPCRs potrebbe contribuire allo sviluppo di nuove strategie terapeutiche volte a prevenire e/o ritardare la crescita tumorale. Nel presente studio, è stato dimostrato che lo Zn è coinvolto nel cross-talk funzionale tra IGF-IR, EGFR e GPER in cellule di tumore mammario e fibroblasti tumore-associati (CAFs). In particolare, è stato dimostrato che GPER, IGF-IR e EGFR contribuiscono agli effetti stimolatori indotti da ZnCl2 nella progressione del ciclo cellulare, nella proliferazione e nella migrazione di cellule di carcinoma mammario e dei CAFs. I nostri risultatievidenziano nuovi meccanismi molecolari attraverso i quali lo Zn può indurre effetti stimolatori in cellule di tumore mammario e nei CAF, suggerendo pertanto nuovi potenziali approcci farmacologici nel trattamento del carcinoma mammario.Item Bisphenol A induces gene expression changes an proliferative effects through GPER in breast cancer celles and cancer-associated fibroblasts(2012) Pupo, Marco; Maggiolini, Marcello; Sisci, DiegoBisphenol A (BPA) is the principal constituent of baby bottles, reusable water bottles, metal cans, and plastic food containers. BPA exerts estrogen-like activity by interacting with the classical estrogen receptors (ER and ER ) and through the G protein-coupled receptor (GPR30/GPER). In this regard, recent studies have shown that GPER was involved in the proliferative effects induced by BPA in both normal and tumor cells. In this study we evaluated the transduction pathways through which BPA influences cell proliferation and migration in human breast cancer cells and cancer-associated fibroblasts (CAFs), that lack the classical ERs. Specific pharmacological inhibitors and gene-silencing procedures showed that BPA induces the expression of the GPER target genes cFOS, EGR1, and CTGF through the GPER/EGFR/ERK transduction signaling in SKBR3 breast cancer cells and CAFs. Moreover, we observed that GPER is required for growth effects and migration stimulated by BPA in both cell types. Our results indicate that GPER is involved in the biological action elicited by BPA in breast cancer cells and CAFs. Hence, GPER-mediated signaling should be included among the transduction mechanisms through which BPA may stimulate cancer progressionItem PPARγ ligands as novel agents able to inhibit breast tumor growth and progression(2011) Vizza, Donatella; Sisci, Diego; Bonofiglio, DanielaItem Molecular Mechanisms of FXR-mediated Growth Inhibition in Hormone-dependent Cancers(2011) Panza, Salvatore; Sisci, Diego; Catalano, StefaniaItem <> estrogen receptor α is the key regulator of the bifunctional role of FoxO3a transcription factor in breast cancer motility and invasiveness(2013-12-02) Cesario, Maria Grazia; Sisci, DiegoThe role of the Forkhead box class O (FoxO)3a transcription factor in breast cancer migration and invasion is controversial. Here we show that FoxO3a overexpression decreases motility, invasiveness, and anchorage-independent growth in estrogen receptor α-positive (ERα+) cancer cells while eliciting opposite effects in ERα-silenced cells and in ERα-negative (ERα−) cell lines, demonstrating that the nuclear receptor represents a crucial switch in FoxO3a control of breast cancer cell aggressiveness. In ERα+ cells, FoxO3a-mediated events were paralleled by a significant induction of Caveolin-1 (Cav1), an essential constituent of caveolae negatively associated to tumor invasion and metastasis. Cav1 induction occurs at the transcriptional level through FoxO3a binding to a Forkhead responsive core sequence located at position −305/−299 of the Cav1 promoter. 17β-estradiol (E2) strongly emphasized FoxO3a effects on cell migration and invasion, while ERα and Cav1 silencing were able to reverse them, demonstrating that both proteins are pivotal mediators of these FoxO3a controlled processes. In vivo, an immunohistochemical analysis on tissue sections from patients with ERα+ or ERα− invasive breast cancers or in situ ductal carcinoma showed that nuclear FoxO3a inversely (ERα+) or directly (ERα−) correlated with the invasive phenotype of breast tumors. In conclusion, FoxO3a role in breast cancer motility and invasion depends on ERα status, disclosing a novel aspect of the well-established FoxO3a/ERα interplay. Therefore FoxO3a might become a pursuable target to be suitably exploited in combination therapies either in ERα+ or ERα− breast tumors.