title: MicroRNA-29b-1 impairs in vitro cell proliferation, self‑renewal and chemoresistance of human osteosarcoma 3AB-OS cancer stem cells.
abstract: Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we showed a potent downregulation of miR-29b. In this study, after stable transfection of 3AB-OS cells with miR-29b-1, we investigated the role of miR-29b-1 in regulating cell proliferation, sarcosphere-forming ability, clonogenic growth, chemosensitivity, migration and invasive ability of 3AB-OS cells, in vitro. We found that, miR-29b-1 overexpression consistently reduced both, 3AB-OS CSCs growth in two- and three-dimensional culture systems and their sarcosphere- and colony-forming ability. In addition, while miR-29b-1 overexpression sensitized 3AB-OS cells to chemotherapeutic drug-induced apoptosis, it did not influence their migratory and invasive capacities, thus suggesting a context-depending role of miR-29b-1. Using publicly available databases, we proceeded to identify potential miR-29b target genes, known to play a role in the above reported functions. Among these targets we analyzed CD133, N-Myc, CCND2, E2F1 and E2F2, Bcl-2 and IAP-2. We also analyzed the most important stemness markers as Oct3/4, Sox2 and Nanog. Real-time RT-PCR and western-blot analyses showed that miR-29b-1 negatively regulated the expression of these markers. Overall, the results show that miR-29b-1 suppresses stemness properties of 3AB-OS CSCs and suggest that developing miR-29b-1 as a novel therapeutic agent might offer benefits for OS treatment.
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Di Fiore
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Drago-Ferrante
authors.affiliation: INT-CROM, 'Pascale Foundation', National Cancer Institute - Cancer Research Center, Mercogliano, Avellino, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pentimalli
authors.affiliation: INT-CROM, 'Pascale Foundation', National Cancer Institute - Cancer Research Center, Mercogliano, Avellino, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Di Marzo
authors.affiliation: INT-CROM, 'Pascale Foundation', National Cancer Institute - Cancer Research Center, Mercogliano, Avellino, Italy.
authors.forename: Iris Maria
authors.initials: IM
authors.lastname: Forte
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: D'Anneo
authors.affiliation: Laboratory of Biochemistry, Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Carlisi
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: De Blasio
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Giuliano
authors.affiliation: Institute for Cancer Research and Molecular Medicine and Center of Biotechnology - College of Science and Biotechnology, Temple University, Philadelphia, PA, USA.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tesoriere
authors.affiliation: INT-CROM, 'Pascale Foundation', National Cancer Institute - Cancer Research Center, Mercogliano, Avellino, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Giordano
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Polyclinic, Palermo, Italy.
authors.forename: Renza
authors.initials: R
authors.lastname: Vento
mesh_terms: D001859:Bone Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D009361:Neoplasm Invasiveness / Q000235:genetics; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology
chemical_list: C532045:MIRN29a microRNA, human; D035683:MicroRNAs