3066 – DUAL REPLACEMENT OF LNC-MEG3 AND MIR-155 TRIGGER TUMOR SUPPRESSIVE ACTIVITY IN MULTIPLE MYELOMA

Abstract

Background: Multiple Myeloma is an aggressive hemopoietic malignancy with high morbidity and mortality. Although new therapeutic strategies have improved the clinical outcome, the disease is still incurable, therefore, the development of promising molecular targets becomes an urgent need. Recent evidence demonstrated a definitive tumor suppressor role of Long non-coding RNA maternally expressed gene 3 (MEG3) and miR-155 in Multiple Myeloma (MM), however, their biological role remains unclear. It has been demonstrated that both markers are downregulated in MM patients compared to healthy. Objectives: We aimed to investigate the biological effect of double hit replacement for both lnc-MEG3 and miR-155 in MM cells, and compare it with the effect of each biomarker separately. Methods: MM cells were transfected by MEG3 overexpression plasmid and miR-155 mimic, the miR-155 and lnc-MEG3 expression levels were measured by qRT-PCR. MTT assay was performed to assess the cell proliferation, cell cycle, and apoptosis were monitored by Flow cytometry analysis. Results: lnc-MEG3 and miR-155 were downregulated in MM cells. In- vitro overexpression of lnc-MEG3 and miR-155 suppresses cell proliferation, induce cell cycle arrest, and promote apoptosis, the effect was more prominent with upregulation of both markers than with each individual biomarker. Conclusion: the present data demonstrate that dual overexpression of lnc-MEG3 and miR-155 elicits a powerful dual tumor suppressor effect in MM cells, in spite they have different signaling pathways, thus providing a promising therapeutic strategy in MM patients.