Combined therapy with a thymidylate synthase-inhibiting vector and S-1 has effective antitumor activity against 5-FU-resistant tumors
Combined therapy with a thymidylate synthase-inhibiting vector and S-1 has effective antitumor activity against 5-FU-resistant tumors
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DOI：
10.3892/ijo.2010.880
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发表时间：
2011-02-01
影响因子：
5.2
通讯作者：
Wada, Hiromi
中科院分区：
文献类型：
--
作者：
Kadota, Kyuichi;Huang, Cheng-Long;Wada, Hiromi
高水平的肿瘤内胸苷酸合成酶（TS）表达与5-氟尿嘧啶（5-FU）耐药相关。为了建立一种新的治疗5-FU耐药肿瘤的方法，使用腺病毒载体表达短发夹RNA（shRNA）靶向TS的基因治疗的疗效进行了研究。构建了人U6启动子调控下的复制缺陷型重组腺病毒载体（Ad-shTS）。使用三种5-FU耐药癌细胞系DLD-1/5 FU、KM 12 C/5 FU和NUGC-3/5 FU。用Ad-shTS转导有效地下调了所有三种5-FU耐药肿瘤细胞中的TS表达。MTT法显示Ad-shTS能显著抑制3种5-FU耐药肿瘤细胞的生长。此外，与单独的5-FU处理和单独的Ad-shTS处理相比，Ad-shTS和5-FU的组合处理显示出显著更大的肿瘤细胞生长抑制。通过体内实验，将替加氟、吉美拉西和奥替拉西钾的组合S-1用于5-FU治疗。Ad-shTS和S-1的联合治疗被发现对裸鼠中的5-FU抗性DLD-1/5 FU异种移植物具有最强的抗肿瘤作用，与单独的S-1治疗和单独的Ad-shTS治疗相比。此外，与单独用S-1处理的肿瘤和单独用Ad-shTS处理的肿瘤相比，用Ad-shTS和S-1组合处理的肿瘤中的凋亡指数显著更高。因此，TS抑制性腺病毒载体和S-1的联合治疗对5-FU耐药肿瘤具有有效的抗肿瘤活性。
High levels of intratumoral thymidylate synthase (TS) expression are associated with resistance to 5-fluorourcil (5-FU). In order to establish a new treatment method for 5-FU-resistant tumors, the efficacy of gene therapy was investigated using an adenoviral vector expressing short hairpin RNA (shRNA) targeting TS. A replication-deficient recombinant adenoviral vector expressing shRNA targeting TS was constructed under the control of the human U6 promoter (Ad-shTS). Three 5-FU-resistant cancer cell lines, DLD-1/5FU, KM12C/5FU and NUGC-3/5FU, were used. Transduction with Ad-shTS effectively downregulated TS expression in all three 5-FU-resistant tumor cells. MTT assays demonstrated that treatment with Ad-shTS significantly inhibited the growth of all three 5-FU-resistant tumor cells. Furthermore, combined treatment with Ad-shTS and 5-FU demonstrated significantly greater inhibition of tumor cell growth in comparison to 5-FU treatment alone and Ad-shTS treatment alone. S-1, a combination of tegafur, gimeracil and oteracil potassium, was used for the 5-FU treatment by in vivo experiments. The combined treatment of Ad-shTS and S-1 was found to have the strongest antitumor effect against 5-FU-resistant DLD-1/5FU xenografts in nude mice in comparison to S-1 treatment alone and Ad-shTS treatment alone. Furthermore, the apoptotic index in tumors treated with combined Ad-shTS and S-1 was significantly higher in comparison to that in tumors treated with S-1 alone and that in tumors treated with Ad-shTS alone. Consequently, the combined treatment of the TS-inhibiting adenoviral vector and S-1 has effective antitumor activity against 5-FU-resistant tumors.