LncRNA MALAT1 silencing represses CXCL12-induced proliferation, invasion, and homing behavior in multiple myeloma by inhibiting CXCR4.

Background: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified in multiple myeloma (MM); its influence on the homing behavior in MM cells is unclear. This study elucidates the impact and mechanism by which MALAT1 affects the homing behavior in MM cells.

Methods: Bone marrow was obtained from patients with MM. MALAT1 and C-X-C motif chemokine receptor 4 (CXCR4) expression in cluster of differentiation 138-purified (CD138) plasma cells were detected by qRT-PCR and Western blotting. MALAT1, CXCR4, and C-X-C motif chemokine ligand 12 (CXCL12) influences on MM cell viability, proliferation, and invasion was monitored by CCK-8, 5-Ethynyl-2'-deoxyuridine, and Transwell assays. qRT-PCR, Western blotting, and ELISA were utilized to detect homing effect-related proteins in MM cells, including intercellular adhesion molecule 1 (ICAM-1) and very late antigen-4 (VLA-4).

Results: MALAT1 and CXCR4 were overexpressed in CD138-purified plasma cells from bone marrow of MM patients, associating with bone damage. MALAT1 upregulated CXCR4 in MM cells. MALAT1 overexpression enhanced MM cell viability, proliferation, and invasion, whereas CXCR4 silencing reversed them. CXCR4 silencing attenuated MALAT1 induction on ICAM-1 and VLA-4 expression in MM cells. CXCL12 upregulation intensified MM cell proliferation and invasion and ICAM-1 and VLA-4 expression in MM cells. MALAT1 silencing counteracted the impact of CXCL12.

Conclusion: MALAT1 silencing may repress CXCL12 induction on MM cell proliferation, invasion, and homing behavior by inhibiting CXCR4. MALAT1 may be a promising target for MM treatment.