抑制Src酪氨酸激酶活性对人肺癌A549/DDP细胞耐药性及MDR1和LRP表达的影响 Translated title: Effect of Src Tyrosine Kinase Inhibition on the Drug-resistance as well as MDR1 and LRP Expression of the Human Cis-platinum-resistant Lung Cancer Cell Line A549/DDP

Abstract

背景与目的

本研究旨在探讨抑制Src酪氨酸激酶活性对人肺癌A549/DDP细胞耐药性及多药耐药蛋白（muti-drug resistance 1, MDR1）和肺耐药相关蛋白（lung resistance-related protein, LRP）表达的影响。

方法

以Src酪氨酸激酶抑制剂作用于A549/DDP细胞，应用Western blot法检测肿瘤细胞Src酪氨酸激活性的变化，CellTiter-Glo发光法检测肿瘤细胞药物敏感性的变化，流式细胞仪检测肿瘤细胞Rh-123含量变化，Western blot法和RT-PCR检测肿瘤细胞MDR1和LRP表达变化。

结果

Src酪氨酸激酶抑制剂可下调A549/DDP细胞中Src酪氨酸激活性，2.5 μM和10 μM Src酪氨酸激酶抑制剂作用肿瘤细胞后，肿瘤细胞药物敏感性提高，逆转倍数（reversal fold, RF）分别为1.59倍和2.10倍，肿瘤细胞中Rh-123含量分别提高了1.21倍和1.59倍，MDR1 mRNA表达分别是对照组的53.8%和27.5%，LRP mRNA表达分别是对照组的59.3%和21.4%，MDR1和LRP蛋白表达水平明显下降。

结论

抑制A549/DDP细胞中Src酪氨酸激酶活性可逆转肿瘤细胞多药耐药性，提高肿瘤细胞药物敏感性，其机制可能与降低细胞MDR1和LRP表达有关。

Translated abstract

Background and objective

The aim of this study is to investigate the effect of Src tyrosine kinase inhibition on the drug-resistance as well as the expression of multidrug resistance 1 (MDR1) and lung resistance-related protein (LRP) of the human cis-platinum-resistant lung cancer cell line A549/DDP.

Methods

4-Anilinoquirazoline was used to inhibit Src tyrosine kinase activity in A549/DDP. Western blot analysis was used to detect the Src tyrosine kinase activity. CellTiter-Glo assay was used to detect the drug sensitivity of tumor cells. Flow cytometry was used to detect the intracellular Rh-123 content. Western blot and real-time PCR assay were used to detect the expression of tumor MDR1 and LRP.

Results

4-Anilinoquirazoline can down-regulate the cellular Src tyrosine kinase activity in A549/DDP. After treatment with 2.5 μM and 10 μM of 4-anilinoquirazoline, the cells became more sensitive to the drug and the reversal folds (RFs) of tumor cell sensitivity to the drug were 1.59- and 2.10-fold, respectively. The intracellular content of Rh-123 improved by 1.21- and 1.59-fold, respectively. The mRNA levels of MDR1 were 53.8% and 27.5% of the control, respectively. The mRNA level of LRP was 59.3% and 21.4% of the control, respectively. The expression of MDR1 and LRP protein significantly decreased.

Conclusion

The inhibition of Src tyrosine kinase activity in A549/DDP cells can reverse multi-drug resistance and increase the sensitivity of the cells to the drug. The mechanism may be related to the down-regulation of cellular MDR1 and LRP.