Comparison of breast cancer cell culture models and drug sensitivity study

Abstract

Objective A three-dimensional (3D) culture model of human breast cancer MCF-7 cells was constructed and compared with a two-dimensional (2D) culture model to observe its drug sensitivity to doxorubicin. Methods A 2D culture model was established by using a planar culture plate, and a 3D culture model was established using an ultra-low adsorption culture plate. The morphology and growth of MCF-7 cells in the two culture models were observed under microscope. Two culture models were determined by immunohistochemistry. Expression of B cell lymphoma/leukemia-2 (bcl-2), proliferation cell nuclear antigen (Ki-67) and Permeability glycoprotein (P-gp) in cells; cell proliferation was detected by methyl thiazol tetrazolium (MTT) assay, and drug sensitivity of MCF-7 cells to doxorubicin under different culture conditions was compared; reverse transcriptase-polymerase chain reaction (RT-PCR) The gene expression levels of P-gp and CD44 were detected, and the protein expression levels of P-gp and CD44 were detected by Western blotting. Differences between groups were analyzed and compared using independent sample t-test. Results In the 3D model, MCF-7 cells aggregated and rapidly formed typical multicellular spheres; while in 2D culture, cells dispersed in adherent growth. The positive expression of bcl-2 and P-gp in the 3D group (0.159±0.127, 0.115±0.621) was significantly higher than that in the 2D group (0.144±0.151, 0.058±0.374, t=2.288, 2.500, P<0.05), Ki-67 expression. (0.034±0.175) was lower than 2D group (0.069±0.351, t=2.832, P<0.05). The proliferation inhibition rate of doxorubicin in each concentration of MCF-7 cells in 3D group (42.75±2.24, 49.21±4.80, 50.64±3.93, 51.40±4.13, 59.21±4.07, 60.64±3.08, 61.40±2.57) was significantly lower than that of 2D group. (50.37±4.02, 73.53±5.67, 64.10±3.89, 65.53±3.80, 74.10±4.14, 83.53±3.17, 84.10±3.15, t=3.701, 7.319, 5.443, 5.632, 5.734, 11.589, 12.487, P<0.05) And the proliferation inhibition rate of the two groups of cells increased significantly with the increase of drug concentration. The expression levels of P-gp and CD44 in the 3D group (2.085±0.235, 1.115±0.741) were significantly higher than those in the 2D group (1.408±0.158, 0.708±1.175, t=5.339, 4.795, P<0.05), protein level (0.432±). 0.197, 0.759±0.356) was also higher than the 2D group (0.154±0.094, 0.305±0.103, t=2.851, 2.737, P<0.05). Conclusion The tumor characteristics of MCF-7 cells in 3D culture were significantly different from those in 2D culture, and the drug sensitivity of the 3D group was higher, which provided an experimental basis for in vitro drug testing and drug resistance related mechanisms. Key words: Breast cancer; Three dimensional cell culture; Doxorubicin; Drug sensitivity