Effects of rotary cell culture system‐simulated microgravity on the ultrastructure and biological behavior of human MDA‐MB‐231 breast cancer cells

Abstract

Objective: This study aimed to investigate changes in the ultrastructure, apoptosis, cycle progression, and migration ability of human MDA-MB-231 breast cancer cells under simulated microgravity conditions. Methods: MDA-MB-231 breast cancer cells were cultured in a rotary cell culture system bioreactor to simulate microgravity for 7 days. The cells were randomly divided into a simulated microgravity (SMG) group and normal gravity control (NG) group. Changes in apoptosis, ultrastructure, cell cycle, and migration ability were evaluated.Results: Transmission electron microscopy showed that cells in the SMG group had more secondary lysosomes than the NG groups. The flow cytometry assay showed that the proportion of apoptotic cells in the SMG group was significantly increased compared with the NG group; additionally, the median and interquartile spacing of the proportion of cells in the G0/G1 phase in the SMG group was lower than in the NG group, but the proportion of cells in the S phase was increased in the SMG group compared with the NG group. The transwell migration assay showed that cell migration in the SMG group was significantly reduced compared with the NG group. The expression of BCL-2 and MMP9 in the SMG group was decreased compared with the NG group, whereas the expression of cyclin D3 in the SMG group was increased. Conclusion: Simulated microgravity through rotary cell culture system had significant effects on human MDA-MB-231 breast cancer cells: the cell cycle and ultrastructure were impaired, apoptosis increased, migration ability decreased, and the expression of BCL-2, cyclin D3, and MMP9 were affected. K E Y W O R D S cell apoptosis, cell migration, cell ultrastructure, MDA-MB-231 breast cancer, simulated microgravity 1

Recent Advances in Multicellular Tumor Spheroid Generation for Drug Screening

“…It is designed as a bioreactor system to simultaneously incorporate the ability to culture multiple types of cells with low turbulence and high mass transfer of nutrients. Jiang et al, (2019) investigated human MDA-MB-231 breast cancer cells in the RCCS to examine microgravity on the ultrastructure [31]. They aimed to determine the changes in the apoptosis, ultrastructure, and cycle progression for seven days.…”

Influence of Microgravity on Apoptosis in Cells, Tissues, and Other Systems In Vivo and In Vitro

“…Cancer cell death has often been attributed to a dysfunctional cytoskeleton or cell cycle arrest caused by microgravity [ 160 , 161 , 162 ]. In addition, abnormal expression of apoptosis-related proteins (p53, Fas, Bax, p21, and Bcl-2) and tumor suppressor genes ( TP53 , PTEN , and FOXO3 ) has been found in cancer cells that showed increased apoptosis [ 6 , 124 , 151 , 152 , 161 , 163 , 164 ].…”

“…This could explain the different starting points of apoptosis in microgravity cultures: In ML-1 and ONCO-DG1 thyroid cancer cells, apoptosis increased after 24 h exposure to simulated microgravity [ 6 , 140 ], whereas in MDA-MB-231 breast cancer and SGC-7901 gastric adenocarcinoma cells, apoptosis increased only after 72 h [ 149 , 152 ]. On the other hand, the number of secondary lysosomes also increased in MDA-MB-231 cells cultured in a RCCS [ 160 ]. A possible role of miRNA expression in the regulation of autophagy-related apoptosis in microgravity needs to be investigated in future studies [ 172 ].…”

Breast Cancer Cells in Microgravity: New Aspects for Cancer Research

“…This way, it can counteract the pro-apoptotic stress occurring during tumorigenesis. Recently, Jiang et al [ 86 ] described that apoptosis of MDA-MB-231 cells was promoted by RCCS culture (7 days) by decreased expression of the anti-apoptotic Bcl-2 as well as increased expression of the pro-apoptotic Fas protein, further accompanied by the appearance of a large number of lysosomal and vacuolar structures.…”

“…For MCF-7 cells, Qian et al [ 78 ] found that the invasive ability decreased after clinostat exposure together with a reduced expression of matrix-metallopeptidases (MMP-2, MMP-9) and vinculin. A transwell migration assay showed that the migration of MDA-MB-231 cells was also significantly reduced after 72 h on an RCCS [ 86 ]. The authors concluded that the decrease in MMP-9 expression in MDA-MB-231 cells might be closely related to a decrease in migration ability in s-µ g .…”