Novel 5-fluorouracil-resistant human esophageal squamous cell carcinoma cells with dihydropyrimidine dehydrogenase overexpression.
Novel 5-fluorouracil-resistant human esophageal squamous cell carcinoma cells with dihydropyrimidine dehydrogenase overexpression.
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DOI：
10.14989/doctor.k19597
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发表时间：
2015-07
影响因子：
5.3
通讯作者：
Osamu Kikuchi;S. Ohashi;Y. Nakai;S. Nakagawa;K. Matsuoka;T. Kobunai;T. Takechi;Y. Amanuma;M. Yoshioka;Tomomi Ida;Yoshihiro Yamamoto;Y. Okuno;S. Miyamoto;H. Nakagawa;K. Matsubara;T. Chiba;M. Muto
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文献类型：
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作者：
Osamu Kikuchi;S. Ohashi;Y. Nakai;S. Nakagawa;K. Matsuoka;T. Kobunai;T. Takechi;Y. Amanuma;M. Yoshioka;Tomomi Ida;Yoshihiro Yamamoto;Y. Okuno;S. Miyamoto;H. Nakagawa;K. Matsubara;T. Chiba;M. Muto
5-氟尿嘧啶(5-FU)是治疗食管鳞状细胞癌(ESCC)的关键药物，但其耐药问题一直是制约其临床应用的重要因素。为了阐明5-FU耐药的机制，我们首次建立了耐5-FU的食管癌细胞系TE-5R，通过逐步增加5-FU的浓度来建立耐药细胞系TE-5R。5-FU的半数抑制浓度显示TE-5R细胞对5-FU的耐药性是亲本TE-5细胞的15.6倍。TE-5R细胞显示包括DPYD基因在内的染色体1p的区域拷贝数扩增，以及参与5-FU降解的二氢嘧啶脱氢酶(DPD)的高mRNA和蛋白表达。与TE-5细胞相比，5-FU处理后TE-5R细胞内5-FU浓度显著降低，5-FU代谢产物α-氟尿嘧啶丙酸浓度显著升高。反之，DPD抑制剂吉美拉西显著增加TE-5R细胞内5-FU浓度，降低细胞内FUPA浓度，减弱5-FU耐药性。这些结果表明，TE-5R细胞对5-FU的耐药性是由于DPD过表达导致5-FU的快速降解所致。通过DPYD基因拷贝数扩增和相应的DPD过表达来研究5-FU耐药的ESCC，可能为探索5-FU耐药的ESCC的治疗策略提供新的生物学证据。
5-Fluorouracil (5-FU) is a key drug for the treatment of esophageal squamous cell carcinoma (ESCC); however, resistance to it remains a critical limitation to its clinical use. To clarify the mechanisms of 5-FU resistance of ESCC, we originally established 5-FU-resistant ESCC cells, TE-5R, by step-wise treatment with continuously increasing concentrations of 5-FU. The half maximal inhibitory concentration of 5-FU showed that TE-5R cells were 15.6-fold more resistant to 5-FU in comparison with parental TE-5 cells. TE-5R cells showed regional copy number amplification of chromosome 1p including the DPYD gene, as well as high mRNA and protein expressions of dihydropyrimidine dehydrogenase (DPD), an enzyme involved in 5-FU degradation. 5-FU treatment resulted in a significant decrease of the intracellular 5-FU concentration and increase of the concentration of α-fluoro-ureidopropionic acid (FUPA), a metabolite of 5-FU, in TE-5R compared with TE-5 cells in vitro. Conversely, gimeracil, a DPD inhibitor, markedly increased the intracellular 5-FU concentration, decreased the intracellular FUPA concentration, and attenuated 5-FU resistance of TE-5R cells. These results indicate that 5-FU resistance of TE-5R cells is due to the rapid degradation of 5-FU by DPD overexpression. The investigation of 5-FU-resistant ESCC with DPYD gene copy number amplification and consequent DPD overexpression may generate novel biological evidence to explore strategies against ESCC with 5-FU resistance.