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Updated: Jul 10, 2026
High-Throughput In Vitro Assay using Patient-Derived Tumor Organoids
Published on: June 14, 2021
In vitro evaluation of dose-response curve for paclitaxel in breast cancer
Tatsuya Yoshimasu1, Shoji Oura, Issei Hirai
1Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, 641-8509, Japan. yositatu@wakayama-med.ac.jp
Background:
The dose-response curve for anticancer agents cannot be evaluated by studying patients directly. To investigate individual differences in the dose-response curve for paclitaxel in breast cancer, we utilized the histoculture drug response assay (HDRA) technique.
Materials And Methods:
Twenty specimens obtained from breast cancer patients who underwent surgical resection were used in this study. The inhibition rates of paclitaxel at several concentrations were measured and fitted to a sigmoid dose-response curve, using non-linear least squares analysis with the fitting equation y=A(1-1/(1+exp(B(x-log(C))))), where A denotes maximal response; B, slope factor; and C, ED50.
Results:
A dose-response curve was obtained in all tumors. The mean value (+/-SD) of maximum response, slope factor, and ED50 were 90.2+/-5.5%, 9.4+/-4.3, and 36.8+/-17.2 microg/ml, respectively. The slope factor was higher in nuclear grade 3 tumors compared with nuclear grade 1 and 2 tumors.
Conclusion:
An individual dose-response curve for paclitaxel in breast cancer can be obtained using the HDRA technique. Nuclear grade 3 tumors appeared to have more uniform chemosensitivity to paclitaxel compared with nuclear grade 1 and 2 tumors.
