肿瘤细胞的甲硫氨酸依赖性对提高肿瘤化疗疗效的作用

The implication of tumor cells' methionine dependence in chemotherapy

目的探讨肿瘤细胞的甲硫氨酸依赖性在提高肿瘤化疗疗效方面的作用及意义。方法将甲硫氨酸（Ｍｅｔ）依赖性肿瘤细胞ＳＧＣ７９０１、ＭＣＦ７和非Ｍｅｔ依赖性肿瘤细胞Ａ５４９、Ａ３７５培养于Ｍｅｔ－Ｈｃｙ＋和Ｍｅｔ＋Ｈｃｙ－培养基中，加入不同浓度的周期特异性化疗药５Ｆｕ或非周期特异性化疗药ＭＭＣ；在细胞与药物接触不同时间段，用ＭＴＴ比色法检测化疗药物的抑瘤率。结果Ｍｅｔ－Ｈｃｙ＋中的５Ｆｕ对Ｍｅｔ依赖性肿瘤细胞的抑瘤率较Ｍｅｔ＋Ｈｃｙ－中的５Ｆｕ的抑瘤率有显著性提高；而５Ｆｕ对非Ｍｅｔ依赖性肿瘤细胞的抑瘤率，在两种培养基间差异无显著性。ＭＭＣ对Ｍｅｔ依赖性、非Ｍｅｔ依赖性肿瘤细胞的抑瘤率未因培养基的不同而差异有显著性。结论利用肿瘤细胞的Ｍｅｔ依赖性，Ｍｅｔ－Ｈｃｙ＋培养基可显著提高周期特异性化疗药（５Ｆｕ）对Ｍｅｔ依赖性肿瘤细胞的抑瘤率，但不能提高周期非特异性化疗药（ＭＭＣ）的抑瘤率。

Objective\ To study the implication of tumor cells' methionine (Met) dependence in promoting the effects of chemotherapy.Methods\ Met dependent tumor cells (SGC 7901 and MCF 7) and Met independent tumor cells (A549 and A375) were cultured in Met - Hcy + and Met + Hcy - media separately, then cell cycle specific chemotherapeutic agent (5 Fu) and cell cycle nonspecific chemotherapeutic agent (MMC) in different concentration gradients were added. The inhibitory rate of tumor cells were tested by MTT assay after different contacting time between the cells and the agents. Results\ The combination of 5 Fu with Met - Hcy + medium made a significantly higher inhibitory rate to Met dependent tumor cells than the combination of Met + Hcy - medium with 5 Fu. However, to Met independent tumor cells, there was no significant difference of inhibitory rate that 5 Fu could make, whether it was combined with Met - Hcy + or Met + Hcy - medium. As a cell cycle nonspecific chemotherapeutic agent, MMC did not make significantly different in inbibitory rate between Met - Hcy + medium and Met + Hcy - medium, whether to Met dependent tumor cells or Met nondependent tumor cells.Conclusion\ In the light of Met dependence of tumor cells, Met - Hcy + medium can significantly increase the inhibitory rate of cell cycle specific chemotherapeutical agent to Met dependent tumor cells, but cannot do it when the drug is cell cycle nonspecific chemotherapeutical agent.