New strategy against pancteato-biliary carcinoma using NK4, a four-kringle antagonist of hepatocyte growth factor

由于胰腺癌的高度侵袭性，即侵袭性、传播性和转移性，患者的结局是病态的。更好地认识和干预胰腺癌的恶性行为可能为治疗提供新的方向。本文报道了肝细胞生长因子(HGF)对人胰腺癌细胞高运动性和侵袭性的诱导，并用新发现的HGF拮抗剂NK4阻断这些特性。在我们使用的8个人胰腺癌细胞系(ASPC-1，BxPC-3，H-48N，KP-1N，KP-2，KP-3，MIA Paca-2和Suit-2)中，c-Met/HGF受体都有不同程度的表达。除BxPC-3和MIA Paca-2细胞外，HGF仅在Suit-2和KP-3细胞中表现出较弱的促有丝分裂活性，但对胰腺癌细胞的迁移和侵袭有较强的刺激作用。相反，NK4可抑制HGF诱导的KP-1N、KP-3和Suit-2细胞的迁移和侵袭。在共培养的胰腺成纤维细胞和胰腺癌切除后腹水的影响下，Suit-2细胞的侵袭性也被有效地刺激，但NK4几乎消除了这种情况下癌细胞的侵袭性。胰腺癌手术患者的腹水中始终含有高水平的HGF。此外，携带NK4的腺病毒(Ad-NK4)显著抑制裸鼠移植瘤的生长。这些结果表明，HGF可能参与了胰腺癌的侵袭、扩散和转移，尤其是通过肿瘤-间质相互作用和胰腺癌切除后的侵袭和转移。NK4是HGF的有效拮抗剂，可能具有抗肿瘤侵袭/转移的作用。

Because of the highly aggressive behaviour, i.e., invasive, disseminative, and metastatic properties, the outcome for patients with pancreatic cancer is morbid. A better understanding and interference with the malignant behavior of pancreatic cancer may provide new directions for treatment. We report here the induction of highly motile and invasive properties in human pancreatic cancer cells by hepatocyte growth factor (HGF) and blockage of these properties by NK4, a newly identified antagonist for HGF.In all of 8 human pancreatic cancer cell lines we used (AsPC-1, BxPC-3, H-48N, KP-1N, KP-2, KP-3, MIA PaCa-2 and SUIT-2 cells), the c-Met/HGF receptor was expressed at varying levels. Although weak mitogenic activity of HGF was seen only in SUIT-2 and KP-3 cells, HGF strongly stimulated migration and invasion of these pancreatic cancer cells, except for BxPC-3 and MIA PaCa-2 cells. In contrast, migration and invasion potently induced by HGF in KP-1N, KP-3, and SUIT-2 cells were inhibited by NK4. The invasion of SUIT-2 cells was also potently stimulated with the influence of co-cultured pancreatic fibroblasts and by ascitic fluid obtained after pancreatic cancer resection, however, invasiveness of the cancer cells in such conditions was practically abolished by NK4. Consistently, the ascitic fluid in patients who had undergone pancreatic cancer surgery contained high levels of HGF.Furthermore, Adenovirus harboring NK4 (Ad-NK4) significantly inhibited the growth of transplanted tumors in nude mice. The tumor reduction induced by Ad-NK4 was associated with a decreased number of blood vessels surrounding the tumors.These findings mean that HGF is probably involved in invasion, dissemination, and metastasis of pancreatic cancer, particularly through tumour-stromal interaction and after resection of the pancreatic cancer. NK4, an effective antagonist of HGF, may prove to have the potential for anti-invasion/metastasis.