自然杀伤细胞对高与低表达ABCG_2的人耐药鼻咽癌细胞杀伤作用

Different cytotoxicity of NK cells against high and low expression of ATP-binding cassette transporter (ABCG_2) of human multi-drug resistant nasopharyngeal carcinoma cells

目的:探讨自然杀伤(NK)细胞对高与低表达三磷酸腺苷(ATP)结合转运蛋白G超家族成员2(ABCG2)人多药耐药鼻咽癌CNE2/DDP细胞(ABCG2High细胞、ABCG2Low细胞)的杀伤活性差异。方法:利用免疫磁珠技术分离ABCG2High及ABCG2LowCNE2/DDP细胞、NK细胞,LDH释放测定法检测NK细胞对K562细胞、ABCG2High及ABCG2LowCNE2/DDP细胞的杀伤活性,流式细胞技术(FCM)检测两种靶细胞NKG2D配体表达率及杀伤后靶细胞凋亡率。结果:ABCG2High、AB-CG2LowCNE2/DDP细胞分离后ABCG2表达率分别为(91.40±2.32)%、(1.70±0.24)%,分选后NK细胞CD3-CD16+CD56+细胞的纯度达90%以上,LDH释放测定法检测结果显示,在效靶比为10vs1、20vs1时,NK细胞对ABCG2Low细胞、ABCG2High细胞及K562细胞的杀伤率以ABCG2High细胞最高,凋亡率检测结果显示ABCG2HighCNE2/DDP细胞的凋亡率为(12.90±1.51)%,ABCG2LowCNE2/DDP细胞的凋亡率为(6.13±0.85)%,NKG2D配体表达率检测结果显示AB-CG2HighCNE2/DDP细胞5种NKG2D配体(MICA、MICB、ULBP1、ULBP2、ULBP3)表达率高于ABCG2LowCNE2/DDP细胞。结论:ABCG2HighCNE2/DDP细胞比ABCG2LowCNE2/DDP细胞更容易被NK细胞杀伤,其初步的机制是ABCG2HighCNE2/DDP细胞NKG2D配体表达率高于ABCG2LowCNE2/DDP细胞,导致了ABCG2HighCNE2/DDP细胞对NK的杀伤敏感性增强。

AIM： To investigate the different cytotoxicity sensitivity of high and low expression of ATP-binding cassette transporter （ABCG2） of human multi-drug resistant nasopharyngeal carcinoma CNE2/DDP cell line （ABCG2High cell and ABCG2Low cell） to NK cells. METHODS： ABCG2High CNE2/DDP cells, ABCG2Low CNE2/DDP cells and NK cells were isolated by magnetic activated cell sorting （MACS）. The cytotoxic effects of NK cells against K562, ABCG2High and ABCG2LowWCNE2/DDP cells were detected with LDH releasing assay. The apoptosis rate and expression of NKG2D-ligands on target cells were evaluated by FCM. RESULTS： The expression of ABCG2 in ABCG2High CNE2/DDP and ABCG2 Low CNE2/DDP cells was （91.40 ±2.32） % and （1. 70 ± 0.24） %, respectively. More than 90% of the isola- ted NK cells were CD3 - CD16 ＋ CD56 ＋ cells. As for the cyto- toxicity of NK cells against ABCG2Low, ABCG2High CNE2/ DDP and K562 cells at the E vs T ratio of 10 vs 1 and 20 vs 1, ABCG2High CNE2/DDP cells possessed highest cytotoxic sensitivity. The apoptosis rate of ABCG2High CNE2/DDP cells and ABCG2LowCNE2/DDP cells was （12.90± 1.51 ）% and （6.13 ±0.8.5）%, respectively. The expression of five kinds of NKG2D ligand of ABCG2High CNE2/DDP cells is higher than that of ABCG2LowCNE2/DDP cells. CONCLUSION： ABCG2 High CNE2/DDP cells are more sensitive to NK cells than ABCG2 Low CNE2/DDP cells in cytotoxicity because the expression of NKG2D ligands of ABCG2HighCNE2/DDP cells is higher than that of ABCG2Low CNE2/DDP cells, which results in the cytotoxic sensitivity of increased tumor cells to NK cells.