Establishment of a 5-fluorouracil-resistant triple-negative breast cancer cell line
Katsuyuki Takahashi1, Masako Tanaka, Azusa Inagaki
1Department of Pharmacology, Osaka City University Medical School, Osaka, Japan.
Abstract:
Triple-negative breast cancers (TNBCs) are defined as tumors that lack expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Clinically, TNBC patients are treated with cytotoxic drugs including 5-fluorouracil (5-FU). However, TNBCs develop resistance to such drugs after a series of treatments. To elucidate the mechanisms of drug resistance, establishment of drug-resistant cancer cell lines should be one of the most useful model systems. However, 5-FU-resistant TNBC cell lines have not been previously reported. In this study, we established a 5-FU-resistant cell line, MDA-MB-231/5-FU, from the human TNBC cell line MDA-MB-231, by repeated exposure to stepwise increases in the concentration of 5-FU. The IC₅₀ value of 5-FU for MDA-MB-231/5-FU was 5.5-fold that for the parental cells. The MDA-MB-231/5-FU cell line acquired resistance to not only 5-FU, but also vinorelbine, paclitaxel and gemcitabine. Additionally, we performed iTRAQ-based quantitative proteomics in MDA-MB-231/5-FU cells and the parental cells in order to characterize MDA-MB-231/5-FU. The proteins upregulated in the newly established cells were mainly classified into the categories of 'DNA recombination', 'cell cycle', 'complex assembly', 'cytoskeleton organization', 'transport' and 'negative regulation of cell death'. These proteins may be related to mechanisms of drug resistance in TNBCs. Our established MDA-MB-231/5-FU cell line should be a useful tool for identifying new mechanisms of drug resistance and new drug targets in TNBCs.
Insights
Researchers developed a new 5-fluorouracil (5-FU)-resistant triple-negative breast cancer (TNBC) cell line, MDA-MB-231/5-FU. This model aids in understanding drug resistance mechanisms and identifying new therapeutic targets for TNBC.
Area of Science:
- Oncology
- Molecular Biology
- Proteomics
Background:
- Triple-negative breast cancer (TNBC) lacks key receptors, limiting treatment options.
- Standard chemotherapy, like 5-fluorouracil (5-FU), faces challenges due to acquired drug resistance in TNBC.
- Establishing reliable drug-resistant models is crucial for studying resistance mechanisms.
Purpose of the Study:
- To create and characterize a novel 5-FU-resistant TNBC cell line.
- To investigate the proteomic changes associated with 5-FU resistance in TNBC.
- To provide a valuable tool for future TNBC drug resistance research.
Main Methods:
- Development of a 5-FU-resistant cell line (MDA-MB-231/5-FU) through stepwise drug exposure.
- Assessment of cross-resistance to other chemotherapeutic agents.
- iTRAQ-based quantitative proteomics to compare protein expression between resistant and parental cells.
Main Results:
- The MDA-MB-231/5-FU cell line exhibited a 5.5-fold increase in 5-FU IC₅₀ compared to parental cells.
- Acquired resistance to 5-FU, vinorelbine, paclitaxel, and gemcitabine.
- Upregulation of proteins involved in DNA recombination, cell cycle, complex assembly, cytoskeleton organization, transport, and negative regulation of cell death.
Conclusions:
- The MDA-MB-231/5-FU cell line represents a robust model for TNBC drug resistance.
- Identified protein categories may play significant roles in mediating chemoresistance.
- This cell line will facilitate the discovery of novel drug resistance mechanisms and therapeutic targets in TNBC.
