Abstract
Background: miRNAs have been defined as a tumor suppressor or oncogene (oncomiR) in several human cancers. We have conducted a systematic review highlighting and specifically focusing in the advancements in preclinical molecular imaging to study in vivo the delivery and the therapeutic efficacy of miRNAs in mouse models of breast cancer.Methods: A systematic review of English articles published in peer-reviewed journals using PubMed® (including MEDLINE®), EMBASE, BIOSIS™, Scopus was performed. Search terms included breast cancer, mouse, mice, microRNA(s) and miRNA(s). The search was focused on the last five years (2015-2021). All studies using miRNA in breast cancer models which included a preclinical imaging evaluation, both in vivo or ex vivo were analyzed. Result: From a total of 2,073 records, 1,221 papers were assessed for full text eligibility, but excluding all those in which there was no use of mouse models of breast cancer, there was not in vivo imaging or ex vivo on whole organs, and without a clear link to a miRNA, our final data extraction was made on a total of 114 manuscripts. The murine genetic background most used in miRNA studies have been resulted to be the Balb/C (46,7%). Regarding cell lines, MDA-MB-231 parental and derived cells were used in most experiments (62,5%). The most used model was the i.v. metastatic model (46,8%), which was obtained via intravenous injection (68,9%) in the tail vein. The modulation of miRNA was obtained mainly by stable transfection with specific lentiviral plasmid or DNA constructs in luciferase- labelled BC cells (54,4%). Bioluminescence resulted the most used tool (64%) and was used as a surrogate of tumor growth for efficacy treatment or for the evaluation of tumorigenicity in miRNA transfected cells (29,9%); for tracking, evaluation of engraftment and for response to therapy in metastatic models (50,6%).Conclusion: this review provides a systematic and focused analysis of all the information currently available and related to the imaging protocols to test miRNA therapy in in vivo mice model of BC and has the purpose to provide an important tool to suggest the best pre-clinical imaging protocol on currently available evidences.
Preclinical Imaging Evaluation of miRNAs’ Delivery and Effects in Breast Cancer Mouse Models: A Systematic Review
