Cytotoxicity of trifluridine correlates with the thymidine kinase 1 expression level
Cytotoxicity of trifluridine correlates with the thymidine kinase 1 expression level
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DOI：
10.1038/s41598-019-44399-6
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发表时间：
2019-05-28
影响因子：
4.6
通讯作者：
Kitao, Hiroyuki
中科院分区：
文献类型：
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作者：
Kataoka, Yuki;Iimori, Makoto;Kitao, Hiroyuki
曲氟尿苷（FTD）是一种三氟胸苷类似物，是口服抗肿瘤药物FTD/TPI（也称为TAS-102）的关键组分，用于治疗难治性转移性结直肠癌。胸苷激酶1（TK 1）被认为对FTD掺入DNA具有重要作用，导致DNA功能障碍和细胞毒性。然而，由于尚未建立TK 1特异性缺陷人癌细胞系，TK 1是否是FTD掺入DNA所必需的以及该事件是否受TK 1表达水平的影响仍不清楚。在这里，我们使用CRISPR/Cas9基因组编辑系统生成了TK 1敲除的人结直肠癌细胞，并通过测量AFMID的表达来验证TK 1敲除的特异性，AFMID与TK 1在相同的基因座上编码。使用TK 1敲除细胞，我们证实TK 1对FTD的细胞敏感性至关重要。此外，我们使用由TK 1敲除细胞生成的具有诱导型TK 1表达的细胞证明了TK 1表达水平与FTD细胞毒性之间的相关性。基于我们发现TK 1表达水平与FTD敏感性相关，我们认为FTD/TPI可能有效治疗TK 1高表达的癌症。
Trifluridine (FTD), a tri-fluorinated thymidine analogue, is a key component of the oral antitumor drug FTD/TPI (also known as TAS-102), which is used to treat refractory metastatic colorectal cancer. Thymidine kinase 1 (TK1) is thought to be important for the incorporation of FTD into DNA, resulting in DNA dysfunction and cytotoxicity. However, it remains unknown whether TK1 is essential for FTD incorporation into DNA and whether this event is affected by the expression level of TK1 because TK1-specific-deficient human cancer cell lines have not been established. Here, we generated TK1-knock-out human colorectal cancer cells using the CRISPR/Cas9 genome editing system and validated the specificity of TK1 knock-out by measuring expression of AFMID, which is encoded on the same locus as TK1. Using TK1-knock-out cells, we confirmed that TK1 is essential for cellular sensitivity to FTD. Furthermore, we demonstrated a correlation between the TK1 expression level and cytotoxicity of FTD using cells with inducible TK1 expression, which were generated from TK1-knock-out cells. Based on our finding that the TK1 expression level correlates with sensitivity to FTD, we suggest that FTD/TPI might efficiently treat cancers with high TK1 expression.