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Activity of trastuzumab emtansine (T-DM1) in 3D cell culture
Jean Zheng Boyer1, Gail D Lewis Phillips2, Hiro Nitta3
1Roche Tissue Diagnostics, 1910 E Innovation Park Drive, Tucson, AZ, 85755, USA. jean.boyer@roche.com.
Background:
Cell spheroids and aggregates generated from three-dimensional (3D) cell culture methods are similar to in vivo tumors in terms of tissue morphology, biology, and gene expression, unlike cells grown in 2D cell cultures. Breast cancer heterogeneity is one of the main drug resistant mechanisms and needs to be overcome in order to increase the efficacy of drug activity in its treatments.
Methods:
We performed a unique 3D cell culture and drug efficacy study with trastuzumab emtansine (Kadcyla®, T-DM1) across five breast cancer cell lines (BT-474, SK-BR-3, MDA-MB-361, MDA-MB-175, and MCF-7) that were previously investigated in 2D cell culture. We performed HER2 IHC staining, cell viability experiments, Gene-protein-assay (GPA), and T-DM1 internalization studies.
Results:
We obtained significantly different results including higher IC50 for some of the cell lines. Our GPA showed some significant heterogeneous HER2 gene and protein expression in 3D cultured spheroids or aggregates. The fluorescent images also showed that a longer incubation time is needed for T-DM1 to be internalized effectively into 3D cultured spheroids or aggregates.
Conclusion:
Our study demonstrated that the difference of T-DM1 drug activity in 3D spheroids or aggregates might be due to tumor heterogeneity and less efficient internalization of T-DM1 that is not seen using 2D cell culture models. Drug studies using 3D cell culture are expected to provide biologically relevant models for determining drug activity in tumor tissue in future drug response and resistance research.
Insights
Three-dimensional (3D) cell cultures reveal breast cancer heterogeneity, impacting drug efficacy. Trastuzumab emtansine (T-DM1) showed reduced effectiveness in 3D models due to heterogeneity and slower internalization.
Area of Science:
- Oncology
- Cell Biology
- Pharmacology
Background:
- Three-dimensional (3D) cell cultures mimic in vivo tumor morphology and biology better than 2D cultures.
- Breast cancer heterogeneity is a key factor in drug resistance.
- Overcoming heterogeneity is crucial for improving breast cancer treatment efficacy.
Purpose of the Study:
- To investigate the drug efficacy of trastuzumab emtansine (T-DM1) in 3D breast cancer cell cultures.
- To compare drug efficacy in 3D versus 2D cell culture models.
- To explore the role of tumor heterogeneity and T-DM1 internalization in drug response.
Main Methods:
- Utilized five breast cancer cell lines in 3D spheroid/aggregate cultures.
- Performed HER2 immunohistochemistry (IHC) staining, cell viability assays, and Gene-Protein Assay (GPA).
- Conducted T-DM1 internalization studies using fluorescent imaging.
Main Results:
- Observed higher IC50 values for T-DM1 in some 3D cell lines compared to 2D.
- GPA revealed heterogeneous HER2 gene and protein expression in 3D cultures.
- Longer incubation times were required for effective T-DM1 internalization into 3D spheroids.
Conclusions:
- Tumor heterogeneity and reduced T-DM1 internalization in 3D models contribute to differential drug activity.
- 3D cell culture models offer a more biologically relevant platform for studying drug response and resistance.
- Findings highlight the limitations of 2D models for predicting in vivo drug efficacy.
