Kwak Jun-Goo, Lee Jungwoo
Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Cancers (Basel). 2023 May 12;15(10):2737. doi: 10.3390/cancers15102737.
Chemoresistance is a significant problem in the effective treatment of bone metastasis. Adipocytes are a major stromal cell type in the bone marrow and may play a crucial role in developing microenvironment-driven chemoresistance. However, detailed investigation remains challenging due to the anatomical inaccessibility and intrinsic tissue complexity of the bone marrow microenvironment. In this study, we developed 2D and 3D in vitro models of bone marrow adipocytes to examine the mechanisms underlying adipocyte-induced chemoresistance. We first established a protocol for the rapid and robust differentiation of human bone marrow stromal cells (hBMSCs) into mature adipocytes in 2D tissue culture plastic using rosiglitazone (10 μM), a PPARγ agonist. Next, we created a 3D adipocyte culture model by inducing aggregation of hBMSCs and adipogenesis to create adipocyte spheroids in porous hydrogel scaffolds that mimic bone marrow sinusoids. Simulated chemotherapy treatment with doxorubicin (2.5 μM) demonstrated that mature adipocytes sequester doxorubicin in lipid droplets, resulting in reduced cytotoxicity. Lastly, we performed direct coculture of human multiple myeloma cells (MM1.S) with the established 3D adipocyte model in the presence of doxorubicin. This resulted in significantly accelerated multiple myeloma proliferation following doxorubicin treatment. Our findings suggest that the sequestration of hydrophobic chemotherapeutics by mature adipocytes represents a potent mechanism of bone marrow microenvironment-driven chemoresistance.
化疗耐药是骨转移有效治疗中的一个重大问题。脂肪细胞是骨髓中主要的基质细胞类型，可能在微环境驱动的化疗耐药形成中起关键作用。然而，由于骨髓微环境在解剖学上难以接近且具有内在的组织复杂性，详细研究仍然具有挑战性。在本研究中，我们建立了二维和三维骨髓脂肪细胞体外模型，以研究脂肪细胞诱导化疗耐药的潜在机制。我们首先建立了一种方案，使用过氧化物酶体增殖物激活受体γ（PPARγ）激动剂罗格列酮（10 μM），在二维组织培养塑料中快速且有效地将人骨髓间充质干细胞（hBMSCs）分化为成熟脂肪细胞。接下来，我们通过诱导hBMSCs聚集并进行脂肪生成，在模拟骨髓血窦的多孔水凝胶支架中创建脂肪细胞球体，从而建立了三维脂肪细胞培养模型。用阿霉素（2.5 μM）进行模拟化疗处理表明，成熟脂肪细胞将阿霉素隔离在脂滴中，从而降低了细胞毒性。最后，我们在阿霉素存在的情况下，将人多发性骨髓瘤细胞（MM1.S）与已建立的三维脂肪细胞模型进行直接共培养。这导致阿霉素处理后多发性骨髓瘤增殖显著加速。我们的研究结果表明，成熟脂肪细胞对疏水性化疗药物的隔离是骨髓微环境驱动化疗耐药的一种有效机制。
