PDF(Pubmed)
Abstract：
OBJECTIVE: Clinical studies showed that prolonged infusion of methotrexate (MTX) leads to more severe adverse reactions than short infusion of MTX at the same dose. We hypothesized that it is the saturation of folate polyglutamate synthetase (FPGS) at high MTX concentration that limits the intracellular synthesis rate of methotrexate polyglutamate (MTX-PG). Due to a similar accumulation rate, a longer infusion duration may increase the concentration of MTX-PG and, result in more serious adverse reactions. In this study, we validated this hypothesis.
METHODS: A549, BEL-7402 and MHCC97H cell lines were treated with MTX at gradient concentrations. Liquid chromatograph-mass spectrometer (UPLC-MS/MS) was used to quantify the intracellular concentration of MTX-PG and the abundance of FPGS and γ-glutamyl hydrolase (GGH). High quality data were used to fit the cell pharmacokinetic model.
RESULTS: Both cell growth inhibition rate and intracellular MTX-PG concentration showed a nonlinear relationship with MTX concentration. The parameter Vmax in the model, which represents the synthesis rate of MTX-PG, showed a strong correlation with the abundance of intracellular FPGS.
CONCLUSIONS: According to the model fitting results, it was confirmed that the abundance of FPGS is a decisive factor limiting the synthesis rate of MTX-PG. The proposed hypothesis was verified in this study. In addition, based on the intracellular metabolism, a reasonable explanation was provided for the correlation between the severity of adverse reactions of MTX and infusion time. This study provides a new strategy for the individualized treatment and prediction of efficacy/side effects of MTX.
METHODS: A549, BEL-7402 and MHCC97H cell lines were treated with MTX at gradient concentrations. Liquid chromatograph-mass spectrometer (UPLC-MS/MS) was used to quantify the intracellular concentration of MTX-PG and the abundance of FPGS and γ-glutamyl hydrolase (GGH). High quality data were used to fit the cell pharmacokinetic model.
RESULTS: Both cell growth inhibition rate and intracellular MTX-PG concentration showed a nonlinear relationship with MTX concentration. The parameter Vmax in the model, which represents the synthesis rate of MTX-PG, showed a strong correlation with the abundance of intracellular FPGS.
CONCLUSIONS: According to the model fitting results, it was confirmed that the abundance of FPGS is a decisive factor limiting the synthesis rate of MTX-PG. The proposed hypothesis was verified in this study. In addition, based on the intracellular metabolism, a reasonable explanation was provided for the correlation between the severity of adverse reactions of MTX and infusion time. This study provides a new strategy for the individualized treatment and prediction of efficacy/side effects of MTX.
摘要：
目的：临床研究表明，在相同剂量下，延长甲氨蝶呤（MTX）输注比短期输注MTX导致更严重的不良反应。我们假设在高MTX浓度下叶酸多谷氨酸合成酶（FPGS）的饱和限制了甲氨蝶呤多谷氨酸（MTX-PG）的细胞内合成速率。由于相似的积累率，较长的输注时间可能会增加MTX-PG的浓度，导致更严重的不良反应。在这项研究中,我们验证了这个假设。
方法:用梯度浓度的MTX处理A549、BEL-7402和MHCC97H细胞系。使用液相色谱-质谱仪（UPLC-MS/MS）定量MTX-PG的细胞内浓度以及FPGS和γ-谷氨酰水解酶（GGH）的丰度。使用高质量数据来拟合细胞药代动力学模型。
结果：细胞生长抑制率和细胞内MTX-PG浓度均与MTX浓度呈非线性关系。模型中的参数Vmax,代表MTX-PG的合成速率，与细胞内FPGS的丰度有很强的相关性。
结论：根据模型拟合结果，证实了FPGS的丰度是限制MTX-PG合成速率的决定性因素。所提出的假设在本研究中得到了验证。此外,基于细胞内的新陈代谢，对MTX不良反应严重程度与输注时间的相关性进行了合理解释.本研究为MTX的个体化治疗和疗效/副作用预测提供了新的策略。
方法:用梯度浓度的MTX处理A549、BEL-7402和MHCC97H细胞系。使用液相色谱-质谱仪（UPLC-MS/MS）定量MTX-PG的细胞内浓度以及FPGS和γ-谷氨酰水解酶（GGH）的丰度。使用高质量数据来拟合细胞药代动力学模型。
结果：细胞生长抑制率和细胞内MTX-PG浓度均与MTX浓度呈非线性关系。模型中的参数Vmax,代表MTX-PG的合成速率，与细胞内FPGS的丰度有很强的相关性。
结论：根据模型拟合结果，证实了FPGS的丰度是限制MTX-PG合成速率的决定性因素。所提出的假设在本研究中得到了验证。此外,基于细胞内的新陈代谢，对MTX不良反应严重程度与输注时间的相关性进行了合理解释.本研究为MTX的个体化治疗和疗效/副作用预测提供了新的策略。
