MiR-199a mediated the dissemination of human mantle cell lymphoma by interacting with the CCR7/CCL21 pair.

Mantle cell lymphoma (MCL) is a rare but deadly subtype of non-Hodgkin's lymphomas because of it can progress rapidly and has a poor prognosis. MicroRNA-199a (miR-199a) is a potential diagnostic marker and therapeutic target for MCL patients. However, the function and molecular mechanisms of miRNA-199a in MCL cells are still unclear. In this study, we first analyzed the levels of miR-199a and C-C chemokine receptor 7 (CCR7) in the tumor tissues and tumor-adjacent tissues, and found that the level of miRNA-199a was lower, whereas the level of CCR7 was higher in tumor tissues. Moreover, overexpression of miR-199a in MCL cells downregulated the level of CCR7. Then, it was found that chemokine (C-C motif) ligand 21 (CCL21), a ligand of CCR7, promoted Granta-519 and Mino cell growth and migration in a concentration-dependent and time-dependent manner. Otherwise, the CCL21/CCR7 pair elevated the level of phosphorylation of protein kinase B and extracellular regulated protein kinases 1/2, upregulated the level of matrix metalloproteinases-2, matrix metalloproteinases-9, and the markers of the mesenchymal phenotype (N-cadherin and vimentin), as well as decreased the level of E-cadherin. However, the functions of CCL21/CCR7 in the growth, migration, and dissemination of MCL cells were decreased by overexpression of miR-199a. Thus, miR-199a inhibited the dissemination of MCL cells by reversing the function of CCL21/CCR7, providing a theoretical basis for miRNA-199a as a potential novel diagnostic marker and therapeutic target for MCL patients.