RESUMO
@#[Abstract] Objective： ：To study the effects of IL-34 over-expression on malignant biological behavior of acute monocytic leukemia (AMoL) cells. Methods: The lentiviral vector pCDH-GFP for over-expressing IL-34 was constructed and infected into AMoL cell lines (THP1 and MOLM-13). Then its effects on proliferation, colony forming and cell cycle as well as apoptosis were tested by the MTS, colony formation assay and Annexin-V/PI staining, respectively. The cell differentiation phenotypes were assessed by fflow cytometry. Nude mice xenograft model was established to observe the tumor size and mass as well as the macrophages recruitment. Results: qPCR analysis showed that the expression of IL-34 mRNAin THP1-IL-34 and MOLM-13-IL-34 cells was nearly 4 000 and 3 000 folds higher than their respective control cells (all P<0.01), indicating that AMoL cell lines over-expressing IL-34 were successfully established. In vitro study showed that over-expression of IL-34 in AMoL cell lines promoted their proliferation potential(72 h:[0.738±0.003] vs [0.646±0.008]; [0.290±0.004] vs [0.247±0.004]; all P<0.01) and colony formation ([127.00 ± 3.37] vs [86.00±4.08]; [160.70±4.70] vs [116.70±3.93]; all P<0.01), whereas had little effect on apoptosis (all P>0.05). Over-expression of IL-34 promotedAMoLcell differentiation towards monocyte-macrophage lineage as the expressions of the monocyte-macrophage markers, CD11b and CD14, were increased whereas the expression of immature marker, CD71, was decreased in AMoL cell lines over-expressing IL-34(all P<0.05). Nude mice xenograft model showed that IL-34 over-expression stimulated macrophage recruitment in tumor tissues (P<0.01). Conclusion: Over-expression of IL-34 in human AMoL cell lines promotes their proliferation, colony forming potential and differentiation towards monocyte-macrophage lineage. Furthermore, IL-34 participates in the process of macrophages recruitment in vivo.