[摘要] 目的：探讨过表达IL-34 对急性单核细胞白血病（acute monocytic leukemia，AMoL）细胞恶性生物学行为的影响。方法：构建IL-34 过表达载体，制备慢病毒载体pCDH-GFP，感染AMoL细胞系THP1 和MOLM-13，通过细胞增殖实验、集落形成实验、PI 染色检测细胞周期法和Annexin-V/PI 法检测IL-34 对AMoL细胞的增殖、集落形成、细胞周期和凋亡的影响，通过流式细胞术分析过表达IL-34 对细胞分化表型的影响，通过裸鼠皮下成瘤模型观察肿瘤大小、质量差异和巨噬细胞募集情况。结果：实验组THP1 和MOLM-13 细胞IL-34 mRNA表达水平分别比对照组提高近4 000 倍和近3 000 倍(均P<0.01），表明已成功构建稳定过表达IL-34 的AMoL细胞系。体外细胞实验结果显示，过表达IL-34 提高THP1 和MOLM-13 细胞的增殖[72 h：(0.738±0.003) vs(0.646±0.008)，(0.290±0.004) vs (0.247±0.004)；均P<0.01]和集落形成能力[(127.00±3.37) vs (86.00±4.08)个，(160.70±4.70) vs(116.70 ± 3.93)个; 均P<0.01]，对细胞的凋亡没有显著影响(均P>0.05)；单核-巨噬细胞分化标志物CD11b 和CD14 表达水平升高，未成熟细胞标志物CD71 表达水平减低，表明IL-34 促进了AMoL细胞向单核-巨噬细胞方向分化（均P<0.05）。裸鼠体内荷瘤实验可见，过表达IL-34 促进瘤组织内巨噬细胞募集(P<0.01)。结论：过表达IL-34 提高AMoL细胞的增殖和集落形成能力，促进细胞向单核-巨噬细胞分化，并促进肿瘤内巨噬细胞的募集。

[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 mRNA in 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 promoted AMoL cell 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.

国家自然科学基金资助项目（No. 81570153, No. 81770183）；天津市自然科学基金重点项目（No.17JCZDJC35000）；中国医学科学院医学与健康科技创新工程资助项目（No. 2016-12M-2-006）