摘要
背景:5-氟尿嘧啶是一种常用的胃癌化疗药物,但临床治疗过程中较易出现耐药现象,影响治疗效果。研究表明肿瘤干细胞对化疗药敏感性较低,可能是导致化疗耐药的重要原因。目的:体外环境下分析胃癌干细胞对5-氟尿嘧啶的敏感性,了解胃癌化疗耐药相关机制。方法:基于克隆形态的分选策略,从人胃癌AGS细胞系内分离胃癌干细胞克隆,采用免疫细胞化学染色分析不同克隆CD44和胸苷酸合成酶的表达,克隆形成实验评估不同类型克隆的自我更新能力,CCK-8法检测不同浓度5-氟尿嘧啶作用下人胃癌AGS细胞克隆生长抑制率。结果与结论:人胃癌AGS细胞经低密度接种培养后,可形成32个不同形态的克隆,其中,副克隆、次克隆、全克隆所占比例分别为19%(6/32)、66%(21/32)、16%(5/32)。全克隆高表达CD44和胸苷酸合成酶,接种后可再次形成大量二代克隆;次克隆弱表达CD44和胸苷酸合成酶,接种后形成少量的二代克隆;副克隆不表达或弱表达CD44和胸苷酸合成酶,接种后未形成二代克隆。在不同浓度5-氟尿嘧啶的作用下,次克隆以及人胃癌AGS细胞的生长抑制率均显著高于全克隆(P均<0.05)。结果表明,在体外条件下,胃癌干细胞对5-氟尿嘧啶敏感性较低,推测其可能为临床化疗耐药的重要机制。
BACKGROUND： 5-Fluorouracil is a common chemotherapy drug for gastric cancer, but it is more likely to develop drug resistance in clinical treatment. Studies have shown that tumor stem cells are lowly sensitive to chemotherapeutic drugs, which may be an important cause of chemotherapy resistance. OBJECTIVE： To analyze the sensitivity of gastric cancer stem cells to 5-fluorouracil in vitro, and to understand the mechanism of drug resistance associated with gastric cancer. METHODS： Based on the sorting strategy, human gastric cancer cell clones were isolated from AGS cell lines. CD44 and thymidylate synthetase expression in different clones was detected using immunocytochemistry analysis. Clone formation assay was used to evaluate self-renewal capacity of different clones. Cell counting kit-8 was used to determine the clonal growth inhibition rate of AGS under treatment with different concentrations of 5-fluorouracil. RESULTS AND CONCLUSION： The AGS cells that were inoculated with low density and cultured could differentiate into 32 forms, including the full clone（16%, 5/32）, the second clone（66%, 21/32） and the accessory clone（19%, 6/32）. Among them, the full clones highly expressed CD44 and thymidylate synthetase, and could generate a great amount of passage 2 clones after inoculation; the second clones showed a weak expression of CD44 and thymidylate synthetase, and could generate a small number of passage 2 clones after inoculation; the accessory clones showed a weak or no expression of CD44 and thymidylate synthetase, and there was no passage 2 clone after inoculation. Under the effect of different concentrations of 5-fluorouracil, the growth inhibition rates of the secondary clones and AGS cells were both higher than that of the full clones（both P 0.05）. These findings indicate that gastric cancer stem cells have a relatively lower sensitivity to 5-fluorouracil in vitro, which is speculated to be an important mechanism of drug resistance.
出处
《中国组织工程研究》
CAS
北大核心
2015年第41期6606-6610,共5页
Chinese Journal of Tissue Engineering Research
