EXPRESSION OF GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR BY MESENCHYMAL STROMAL CELLS BY IN VITRO TRANSCRIBED mRNA. A THERAPEUTIC STRATEGY FOR HEPATOCELLULAR CARCINOMA

CANTERO, MARIA JOSE; BUELONI, BARBARA; FIORE, ESTEBAN; LAMEROLI, LUCÍA; ATORRASAGASTI, CATALINA; MAZZOLINI, GUILLERMO; MALVICINI, MARIANA; BAYO, JUAN; GARCIA, MARINA

Congreso; REUNIÓN CONJUNTA SAIC SAB AAFE AACYTAL 2023; 2023

Sociedad Argentina de Investigaciones Clínicas

Mesenchymal stromal cells (MSCs) are considered potentialvehicles of therapeutic factors. Transfection with invitro transcribed (IVT) mRNA is a promising tool for genetherapy. Our goal was to generate engineered MSCs byIVT mRNA transfection overexpressing granulocyte-macrophagecolony-stimulating factor (MSC-GM) and determinetheir therapeutic effect alone or in combination withdoxorubicin (dox) on a murine model of hepatocellularcarcinoma (HCC). Methods: Ds-Red or GM-CSF IVTmRNAs were transfected using lipofectamine. Gene expressionand cell surface markers were determined byqPCR and flow cytometry respectively. GM-CSF secretionwas determined by ELISA. HCC model was developedby subcutaneous inoculation (SC) of Hepa129 inC3H mice. Tumor size and mice survival were evaluatedafter SC injection of MSC-GM, dox or their combination.Tumor samples were collected for mRNA analysis andflow cytometry. Results: DS-Red expression was observedfrom 2h to 15 days after IVT transfection and didnot affect tumor growth in vivo. MSC-GM maintains thesurface markers unmodified, secret GM-CSF, inducesdifferentiation of dendritic cells and a pro-inflammatoryphenotype of macrophages (J774 cells, p>0.05 t test),and reduces HCC tumor growth in vivo (p>0.05 two-wayANOVA). Even more, combination of the MSC-GM anddox treatments strongly reduces HCC tumor growth inC3H mice (p>0.05 two-way ANOVA) and extended micesurvival in comparison with individual treatments. Notably,dox treatment results in Hepa129 cells immunogeniccell death which in turns increases the macrophagespro-inflammatory phenotype induced by MSC-GM in vitro(p>0.05 ANOVA). Besides, tumors of the MSC-GM+doxtreated group present higher levels of TNF-α, IL1-β andIFN-γ gene expression and have an increased CD8+ Tcells and macrophages infiltration. Conclusions: Our resultsdemonstrate that transfection with IVT mRNA is asuitable strategy to obtain engineered MSCs with therapeuticpurposes for HCC.