Establishment of a 5-fluorouracil-resistant triple-negative breast cancer cell line

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.

Percutaneous Carbon Dioxide Treatment using a Gas Mist Generator Enhances the Collateral Blood Flow in the Ischemic Hindlimb

“…Next, a proteome analysis was performed using a DiNa-AI nano LC System (KYA Technologies, Tokyo, Japan) coupled with a QSTAR Elite hybrid mass spectrometer (AB Sciex) through a NanoSpray ion source (AB Sciex), as previously described 13) . Briefly, mobile phase A included 98% water (2% acetonitrile [ACN], 0.1% formic acid) and mobile phase B included 70% ACN (0.1% formic acid, 30% water).…”

Knockdown of EpCAM Enhances the Chemosensitivity of Breast Cancer Cells to 5-fluorouracil by Downregulating the Antiapoptotic Factor Bcl-2

“…Russo et al showed that certain proteins such as zonulin, glucagon-like peptide-2 (GLP-2), epidermal growth factor (EGF) and ghrelin play a role in the response to FEC in breast cancer cells [4]. Previous studies have shown that the high mortality of breast cancer can be partly attributed to the acquisition of drug resistance during chemotherapy [5], [6]. Despite the steady improvement of 5-FU-basedtreatment regimens, the patient response rate to 5-FU-based chemotherapy remains modest mainly due to the development of drug resistance.…”

Role of uL3 in Multidrug Resistance in p53-Mutated Lung Cancer Cells

“…According to previous studies, 5-FU resistance is caused by an increase in the 5-FU-degrading enzyme dihydropyrimidine dehygrogenase (DPYD) and 5-FU-targeting enzyme thymidylate synthase (TS) [30]. On the other hand, ABC family proteins, such as Multi Drug Reactivity 1 (MDR1), are related to multiple drug resistance in cancer.…”

“…The determinants of the resistance mechanisms to 5-FU include the enzymes involved in the 5-FU metabolism pathway [30]. To exert its cytotoxic effects, 5-FU is converted to its active metabolites by several enzymes and the levels of these enzymes have been associated with 5-FU sensitivity [6].…”

“…To exert its cytotoxic effects, 5-FU is converted to its active metabolites by several enzymes and the levels of these enzymes have been associated with 5-FU sensitivity [6]. Previous results reported that the enhanced expression of dihydropyrimidine dehygrogenase (DPYD) and thymidylate synthase (TS), a 5-FU-degrading enzyme and a 5-FU-targeting enzyme, respectively, correlated with the development of 5-FU resistance [30]. However, we found that the expression of DPYD and TS was not enhanced in rCalu-6 cells.…”