0000000000350747
AUTHOR
Maria Rita Pitari
miR-29b negatively regulates human osteoclastic cell differentiation and function: Implications for the treatment of multiple myeloma-related bone disease
Skeletal homeostasis relies upon a fine tuning of osteoclast (OCLs)-mediated bone resorption and osteoblast (OBLs)-dependent bone formation. This balance is unsettled by multiple myeloma (MM) cells, which impair OBL function and stimulate OCLs to generate lytic lesions. Emerging experimental evidence is disclosing a key regulatory role of microRNAs (miRNAs) in the regulation of bone homeostasis suggesting the miRNA network as potential novel target for the treatment of MM-related bone disease. Here, we report that miR-29b expression decreases progressively during human OCL differentiation in vitro. We found that lentiviral transduction of miR-29b into OCLs, even in the presence of MM cells,…
Selective targeting of IRF4 by synthetic microRNA-125b-5p mimics induces anti-multiple myeloma activity in vitro and in vivo
Interferon regulatory factor 4 (IRF4) is an attractive therapeutic target in multiple myeloma (MM). We here report that expression of IRF4 mRNA inversely correlates with microRNA (miR)-125b in MM patients. Moreover, we provide evidence that miR-125b is downregulated in TC2/3 molecular MM subgroups and in established cell lines. Importantly, constitutive expression of miR-125b-5p by lentiviral vectors or transfection with synthetic mimics impaired growth and survival of MM cells and overcame the protective role of bone marrow stromal cells in vitro. Apoptotic and autophagy-associated cell death were triggered in MM cells on miR-125b-5p ectopic expression. Importantly, we found that the anti-…
miR-29s: A family of epi-miRNAs with therapeutic implications in hematologic malignancies
A wealth of studies has highlighted the biological complexity of hematologic malignancies and the role of dysregulated signal transduction pathways. Along with the crucial role of genetic abnormalities, epigenetic aberrations are nowadays emerging as relevant players in cancer development, and significant research efforts are currently focusing on mechanisms by which histone post-translational modifications, DNA methylation and noncoding RNAs contribute to the pathobiology of cancer. As a consequence, these studies have provided the rationale for the development of epigenetic drugs, such as histone deacetylase inhibitors and demethylating compounds, some of which are currently in advanced p…
Inhibition of miR-21 restores RANKL/OPG ratio in multiple myeloma-derived bone marrow stromal cells and impairs the resorbing activity of mature osteoclasts.
// Maria Rita Pitari 1 , Marco Rossi 1 , Nicola Amodio 1 , Cirino Botta 1 , Eugenio Morelli 1 , Cinzia Federico 1 , Annamaria Gulla 1 , Daniele Caracciolo 1 , Maria Teresa Di Martino 1 , Mariamena Arbitrio 2 , Antonio Giordano 3, 4 , Pierosandro Tagliaferri 1 , Pierfrancesco Tassone 1, 4 1 Department of Experimental and Clinical Medicine and T. Campanella Cancer Center, Magna Graecia University, S. Venuta University Campus, Catanzaro, Italy 2 ISN-CNR, Roccelletta di Borgia, Catanzaro, Italy 3 Department of Human Pathology and Oncology, University of Siena, Siena, Italy 4 Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology,…
A 13 mer LNA-i-miR-221 Inhibitor Restores Drug Sensitivity in Melphalan-Refractory Multiple Myeloma Cells.
Abstract Purpose: The onset of drug resistance is a major cause of treatment failure in multiple myeloma. Although increasing evidence is defining the role of miRNAs in mediating drug resistance, their potential activity as drug-sensitizing agents has not yet been investigated in multiple myeloma. Experimental Design: Here we studied the potential utility of miR-221/222 inhibition in sensitizing refractory multiple myeloma cells to melphalan. Results: miR-221/222 expression inversely correlated with melphalan sensitivity of multiple myeloma cells. Inhibition of miR-221/222 overcame melphalan resistance and triggered apoptosis of multiple myeloma cells in vitro, in the presence or absence of…
MiR-29b antagonizes the pro-inflammatory tumor-promoting activity of multiple myeloma-educated dendritic cells
Dendritic cells (DCs) have a key role in regulating tumor immunity, tumor cell growth and drug resistance. We hypothesized that multiple myeloma (MM) cells might recruit and reprogram DCs to a tumor-permissive phenotype by changes within their microRNA (miRNA) network. By analyzing six different miRNA-profiling data sets, miR-29b was identified as the only miRNA upregulated in normal mature DCs and significantly downregulated in tumor-associated DCs. This finding was validated in primary DCs co-cultured in vitro with MM cell lines and in primary bone marrow DCs from MM patients. In DCs co-cultured with MM cells, enforced expression of miR-29b counteracted pro-inflammatory pathways, includin…