Previously, we established a three-dimensional (3D) bone marrow culture system that maintains normal hematopoiesis, including prolongation of hematopoietic stem cell proliferation and differentiation. To analyze the role of bone marrow stromal cells that compose the microenvironment, the growth of a leukemic cell line (K562) in the 3D condition and with arginine deprivation stress was compared with two-dimensional stromal cell monolayers (2D) and suspension cultures without stromal cells (stroma (−)). Arginine is essential for the proliferation and differentiation of erythrocytes. The proliferation and differentiation of K562 cells cultured in the 3D system were stabilized compared with cells in 2D or stroma (−). Furthermore, the number of K562 cells in the G₀/G₁ phase in 3D was increased significantly compared with cells grown in 2D or stroma (−). Interestingly, the mRNA expression of various hematopoietic growth factors of stromal cells in 3D was not different from 2D, even though supportive activity on K562 cell growth was observed in the arginine deprivation condition. Thus, the hematopoietic microenvironment involves multi-dimensional and complex systems including biochemical and physiochemical factors that regulate quiescence, proliferation, activation, and differentiation of normal hematopoietic cells and cloned leukemic cells. Our 3D culture system may be a valuable new tool for investigating leukemic cell-stromal cell interactions in vitro.

以前，我们建立了三维（3D）骨髓培养系统，该系统可维持正常的造血功能，包括延长造血干细胞的增殖和分化。为了分析组成微环境的骨髓基质细胞的作用，将白血病细胞系（K562）在3D条件下和精氨酸剥夺应激下的生长与二维基质细胞单层（2D）和无基质的悬浮培养进行了比较细胞（基质（-））。精氨酸对于红细胞的增殖和分化至关重要。与2D或基质（-）中的细胞相比，在3D系统中培养的K562细胞的增殖和分化得以稳定。另外，G ₀ / G _1中的K562细胞数与2D或基质（-）中生长的细胞相比，3D中的阶段显着增加。有趣的是，即使在精氨酸剥夺条件下观察到了对K562细胞生长的支持活性，在3D中基质细胞的各种造血生长因子的mRNA表达与2D并无差异。因此，造血微环境涉及多维和复杂的系统，包括调节正常造血细胞和克隆的白血病细胞的静止，增殖，激活和分化的生化和物理化学因素。我们的3D培养系统可能是体外研究白血病细胞与基质细胞相互作用的有价值的新工具。