3D Spheroid Model of Fibroid Growth

INTRODUCTION: Fibroids are 3 times as stiff as surrounding myometrium tissue. Literature describes fibroid stiffness ranging from 5–20 kPa. This project seeks to quantify the effect of environmental stiffness on fibroid growth. METHODS: Myometrium cells (MC) and fibroid cells (FC) were collected from patients undergoing hysterectomy (n=2), and cultured as spheroids. Spheroids were suspended in low-gelling agarose (0.75–1.5%) to achieve different degrees of rigidity, and cultured in 24-well plates (n=6 per condition). Cell viability and proliferation assays were performed. Fluorescent microscopy was used to measure the cross-sectional area of spheroids after 1 and 3 weeks. RESULTS: At week 1, the average cross-sectional area (in μm2) of MC spheroids was 520.68 at 0.75%, and 495.33 at 1.0%. For FC spheroids, values were 1,899.48 at 0.75%, and 2,011.71 at 1.0%. At week 3, the average cross-sectional area of MC spheroids was 580.92 at 0.75% and for FC 2,539.30 at 0.75%. In 1.5% agarose, the ratio of week 3 to week 1 areas was 0.66 for MC, and 0.68 for FC. CONCLUSION: Both cell types initially form spheroids; however, growth with time varies with cell type and agarose concentration (rigidity). At 0.75%, MC formed spheroids after 1 week and underwent arrest of development by week 3. At 1.5% agarose, neither cells withstood mechanical stress over time. Fibroid and myometrium cells respond differently to the same stress. Further studies are warranted to determine if samples from other patients undergo similar responses, and if cells from one fibroid respond similarly to cells from another fibroid within the same patient.