The inhibition of 45A ncRNA expression reduces tumor formation, affecting tumor nodules compactness and metastatic potential in neuroblastoma cells.

Ilaria Penna,Andrea Mescola,Arianna Gigoni,Aldo Pagano,Delfina Costa,Tullio Florio,Antonio Daga,Claudio Canale,Serena Vella,Federico Villa,Debora Russo,Antonella Brizzolara,Claudio Russo,Paola Menichini,Mario Nizzari,Alessandro Poggi

doi:10.18632/oncotarget.14138

Abstract

We recently reported the in vitro over-expression of 45A, a RNA polymerase III-transcribed non-coding (nc)RNA, that perturbs the intracellular content of FE65L1 affecting cell proliferation rate, short-term response to genotoxic stress, substrate adhesion capacity and, ultimately, increasing the tumorigenic potential of human neuroblastoma cells. In this work, to deeply explore the mechanism by which 45A ncRNA contributes to cancer development, we targeted in vitro and in vivo 45A levels by the stable overexpression of antisense 45A RNA.45A downregulation leads to deep modifications of cytoskeleton organization, adhesion and migration of neuroblastoma cells. These effects are correlated with alterations in the expression of several genes including GTSE1 (G2 and S phase-expressed-1), a crucial regulator of tumor cell migration and metastatic potential. Interestingly, the downregulation of 45A ncRNA strongly affects the in vivo tumorigenic potential of SKNBE2 neuroblastoma cells, increasing tumor nodule compactness and reducing GTSE1 protein expression in a subcutaneous neuroblastoma mouse model. Moreover, intracardiac injection of neuroblastoma cells showed that downregulation of 45A ncRNA also influences tumor metastatic ability. In conclusion, our data highlight a key role of 45A ncRNA in cancer development and suggest that its modulation might represent a possible novel anticancer therapeutic approach.

Highlights

Non-codingRNA are widely recognized as crucial regulators of several physiological and pathological processes [1].We recently reported that the expression of 45A [2], a pol III-transcribed non-coding RNA (ncRNA), perturbs the intracellular content of FE65L1 (APBB2, amyloid beta (Aβ) precursor protein-binding, family B, member 2, NP_004298.1), a protein potentially involved in the pathogenesis of Alzheimer disease (AD) due to its binding to amyloid precursor protein (APP, P05067) [3], [4]
We recently reported that the expression of 45A [2], a pol III-transcribed ncRNA, perturbs the intracellular content of FE65L1 (APBB2, amyloid beta (Aβ) precursor protein-binding, family B, member 2, NP_004298.1), a protein potentially involved in the pathogenesis of Alzheimer disease (AD) due to its binding to amyloid precursor protein (APP, P05067) [3], [4]
We have detected an Anti45A-dependent decrease of cell proliferation rate in a non-Myc-N amplified neuroblastoma cell line, SH-SY5Y, evidencing that the results reported in this work can be obtained in different neuroblastoma cells

Summary

Introduction

Non-coding (nc)RNA are widely recognized as crucial regulators of several physiological and pathological processes [1].We recently reported that the expression of 45A [2], a pol III-transcribed ncRNA, perturbs the intracellular content of FE65L1 (APBB2, amyloid beta (Aβ) precursor protein-binding, family B, member 2, NP_004298.1), a protein potentially involved in the pathogenesis of Alzheimer disease (AD) due to its binding to amyloid precursor protein (APP, P05067) [3], [4]. Generation of the Aβ peptide and APP C-terminal fragment gamma are potentiated by the overexpression of FE65L1 and www.impactjournals.com/oncotarget decreased if an alternatively spliced, different form of the protein is synthesized [2]. In our studies we demonstrated that in neuroblastoma cells FE65L1 exerts a primary role in cell cycle regulation and genomic surveillances. Studying the effects of the 45A ncRNA overexpression on FE65L1 splicing and the consequent Aβ processing, we found, besides an altered amyloid release, an enhanced cell proliferation and, an increase of the tumorigenic potential of tumor-derived cells. Besides the increased tumorigenic potential in vitro, we showed that 45A-overexpressing cells exhibit an enhanced potential to develop tumor in vivo, confirming the active role of 45A ncRNA in the determination of the malignant phenotype of NB cells [2]

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Conclusion