Collagen-Embedded Three-Dimensional Spheroid Model Based on Breast and Cervical Cancer for Drug Screening Application

Background Despite advancements in treatment protocols, breast and cervical cancer are the leading causes of cancer-associated deaths in Indian women. Therefore, there is a need to develop more effective treatment strategies and better tumor models to test novel therapeutics. This study reports the development of a bioengineered three-dimensional (3D) model that can mimic in vivo tumors and be used to understand disease pathophysiology, as well as for drug testing/screening applications. Methodology The liquid overlay method was used to generate 3D spheroids of uniform size, based on breast (MDA-MB-231) and cervical (HeLa and CaSki) cancer cell lines. After this, they were embedded in collagen type I. The collagen-embedded spheroids were then subjected to live/dead staining, viability study, and expression of epithelial-mesenchymal transition (EMT) markers at predetermined time points. The 3D spheroids were also subjected to anti-cancer drug testing, followed by a viability assay. The software used for analysis was GraphPad Prism 8.4 (Dotmatics, Boston, Massachusetts, United States) and MS Excel (Microsoft Corporation, Redmond, Washington, United States). Results Uniform-sized, single spheroids for three different cell lines, MDA-MB-231, HeLa, and CaSki, were successfully generated using the liquid overlay technique. There was a significant increase in the viability of 3D spheroids after day 3 of incubation when compared with day 1. Live/dead staining showed the presence of dead cells in the core of the 3D spheroids. Further, EMT markers such as twist, N-cadherin, and fibronectin were found to be elevated in the case of 3D spheroids as compared to the two-dimensional (2D) culture of cancer cells. Additionally, the IC50 values of MDA-MB-231, HeLa, and CaSki spheroids following treatment with an anti-cancer drug, cisplatin, were found to be approximately four to five-fold higher than in the 2D culture. Conclusion The collagen-embedded 3D spheroid model is a robust model that can be used for the generation of 3D spheroids based on various cancer cell lines, recapitulating the properties of solid tumors in vivo. The model further demonstrates its potential to be used as a drug screening platform and can be used for the generation of patient tumor-derived 3D spheroids in the future.