NK4拮抗HGF促进肿瘤细胞凋亡的生物学效应

观察NK4通过拮抗肝细胞生长因子（HGF）诱导不同肿瘤细胞凋亡，研究其生物学作用及分子机制.以足叶乙甙（VP-16）诱导凋亡，分别或经HGF蛋白、NK4蛋白处理5种肿瘤细胞（B细胞淋巴瘤细胞系Raji、人急性粒细胞白血病细胞系HL-60、宫颈癌细胞系HeLa、前列腺癌细胞系PC-3、非小细胞肺癌细胞系A549），采用流式细胞术（FCM）、吖啶橙 (AO) 染色法、苏木素 伊红（HE）染色法定量观察5种肿瘤细胞的凋亡情况，并进行相关分析. FCM发现，经VP-16处理5种肿瘤细胞凋亡率均显著高于对照组(P<0.001)，而HGF+VP-16组凋亡率明显下降(P<0.01)，HGF+NK4+VP-16组细胞凋亡率均明显高于HGF+VP-16组(P<0.05). AO染色和HE染色结果也证实，5种肿瘤细胞经VP-16处理后凋亡率均显著增高 (P<0.001，P<0.001)，而HGF+VP-16组细胞凋亡率均明显低于VP-16组(P<0.001,P<0.01)， HGF+NK4+VP-16组细胞凋亡率均明显高于HGF+VP-16组(P<0.001，P<0.05).此外，发现NK4+VP-16组、HGF+ NK4+VP-16组、VP-16组等3组间凋亡率无统计学差异(P>0.05). 以上结果提示，HGF蛋白可抵抗凋亡诱导剂VP-16的作用, 明显降低细胞凋亡；NK4通过竞争性抑制HGF从而促进肿瘤细胞的凋亡，具有潜在的肿瘤治疗价值.

NK4 Promotes Apoptosis by Antagonizing HGF in Tumor Cells

We studied the induction of tumor cell apoptosis by NK4 with its antagonist effect to hepatocyte growth factor (HGF). Five tumor cell lines (B-cell lymphoma cell line Raji, human acute myeloid leukemia cell line HL-60, cervical cancer cell line HeLa, prostate cancer cell line PC-3, non small cell lung cancer cell lines A549) were analyzed for etoposide (VP-16) induced apoptosis with the presence of HGF protein or NK4. The degree of cell apoptosis were quantified by flow cytometry (FCM) with acridine orange (AO) and hematoxylin-eosin (HE) staining. After VP-16 treatment, higher apoptosis was observed than that of the non-treated control (P<0.001). The HGF + VP-16 treatment decreased the apoptosis rate significantly (P<0.01), while the HGF + NK4 + VP-16 group showed higher apoptosis than that of HGF + VP-16 group (P<0.05). The AO and HE staining results verified the findings in the five tumor cell lines. These results signified that the HGF reduced apoptosis in tumor cells under VP-16 treatment; while NK4 promoted apoptosis possibly through the competitive inhibition of HGF.