Quantitative polymerase Chain reaction profiling of microRNAs in peripheral lymph-monocytes from MGUS subjects

Monoclonal gammopathy of undetermined significance (MGUS) is a pre-malignant abnormality of plasma cells, with increased serum levels of immunoglobulins. Patients with MGUS may evolve to multiple myeloma through a multistep process including deregulated gene expression. microRNAs are small non-coding RNA molecules involved in post-transcriptional regulation of crucial biological processes, such as morphogenesis, cell differentiation, apoptosis, and cancer. This study aimed to evaluate microRNA expression on peripheral lymph-monocytes from MGUS subjects compared with healthy controls using qPCR arrays. Blood samples were collected by venipuncture from fifteen, newly diagnosed MGUS patients and fifteen healthy subjects. A further group (validation group) of six newly diagnosed MGUS patients and five healthy control were enrolled for the validation of miRNAs and their mRNAs target. The study was conducted performing miProfile miRNA qPCR arrays, followed by validation of miRNAs and related mRNA targets through RT-qPCR. The functional interaction between microRNAs and target gene were obtained by Ingenuity Pathways Analysis (IPA). IPA network analysis identified only molecules and relationships experimentally observed in peripheral lymphomonocytes. The following miRNAs :133a-3p, 16−5p, 291−3p, 23a-3p, 205−5p, 17−5p, 7a-5p, 221−3p, 30c-5p, 126a-3p,155−5p, let-7a-5p and 26a-5p, involved in the regulation of genes with a role in lymphocyte homeostasis, cell proliferation, apoptosis, and multiple myeloma (MM) progression, were differently expressed in MGUS with respect to healthy subjects. This miRNA signature and its relative targets could be considered for the formulation of new therapeutic strategies in the prophylaxis or treatment of monoclonal gammopathies.