<p>Characterization of Triple-Negative Breast Cancer MDA-MB-231 Cell Spheroid Model</p>

Abstract

Background: The tumor three-dimensional (3D) spheroid model in vitro is effective on detecting malignant cells and tumorigenesis, and assessing drug resistance. Compared with two-dimensional (2D) monolayer culture, breast cancer (BC) spheroids more accurately reflect the complex microenvironment in vivo, which have been extensively reported in BC research. MDA-MB-231 cells, the triple-negative breast cancer (TNBC) cell line, display representative epithelial to mesenchymal transition (EMT) associated with BC metastasis. However, the characterization of MDA-MB-231 spheroids has been largely unknown at present, which requires further attention. Materials and Methods: Microwell array was conducted for the formation of MDA-MB-231 spheroids. In addition, H&E staining, immunohistochemistry (IHC), CellTiter-Glo ® 3D cell viability assay, and flow cytometry were performed to investigate the structure and growth characteristics. Besides, Transwell and scratch healing assays were carried out to detect the migratory capacities compared with 2D culture. Western blotting and confocal fluorescence were selected to detect the expression of EMT-associated proteins. Additionally, the half maximal inhibitory concentration (IC 50 ) values of antitumor compounds Carboplatin and Doxorubicin were measured to assess drug resistance. Results: The MDA-MB-231 spheroids were viable, which maintained a compact structure with zonation features for up to 9 days. Moreover, those spheroids had a slower growth rate than those cultured as a monolayer and differential zones of proliferation. The migratory capacities were significantly enhanced by transferring the spheroids to 2D adherent culture. Compared with 2D culture, the levels of EMT-associated proteins were significantly upregulated in spheroids. Furthermore, toxicity assessment showed that spheroids exhibited an increased resistance to the antitumor compounds. Conclusion: This study develops the simple spheroids and demonstrates their structure, growth and proliferation characteristics. According to our results, the spheroids are associated with superior EMT and high resistance to toxicological response compared with the standard 2D monocultures.

Collective Polarization of Cancer Cells at the Monolayer Boundary

“…MDA-MB-231 cell line is considered a dangerous subtype among multiple types of human breast cancer [ 39 , 40 ]. Cell polarization is an initial step of epithelial cancer metastasis and invasion.…”

Environmental control of mammary carcinoma cell expansion by acidification and spheroid formation in vitro

“…Effects of environmental acidification on viability of MDA-MB-231 cells were examined to compare their response with less aggressive MCF7 cells. MDA-MB-231 are highly tumorigenic triple negative mammary carcinoma cells 35 , 42 . In contrast with MCF7 cells which exhibited a decrease in viability of over 30% at pH 6.2 compared to pH 7.2 (see Fig.…”

“…Both MDA-MB-231 and MCF7 cells have been reported to display doxorubicin resistance accompanied by loss of E-cadherin junctions along with production of N-cadherins in response to environmental acidification and growth in spheroid cultures 42 , 58 , 59 . Our data indicate that effects of pH on cell viability and extracellular vesicle production are more pronounced by less aggressive MCF7 than more aggressive triple negative MDA-MB-231 cells.…”

Multi-omics data integration reveals correlated regulatory features of triple negative breast cancer

“…This cell line is used to model late-stage breast cancer. 10,11 HCC1937 cell line (Hamon Cancer Center) was established from a grade III infiltrating ductal primary breast tumor from a patient with a germ-line BRCA1 mutation. The primary tumor showed large vacuoles in many of the cells suggestive of secretory variant of infiltrating intraductal carcinoma.…”