Human carcinoma cell growth and invasiveness is impaired by the propeptide of the ubiquitous proprotein convertase furin
Human carcinoma cell growth and invasiveness is impaired by the propeptide of the ubiquitous proprotein convertase furin
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DOI：
10.1158/0008-5472.can-04-2820
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发表时间：
2005-05-15
期刊：
影响因子：
11.2
通讯作者：
Klein-Szanto, AJP
中科院分区：
文献类型：
--
作者：
de Cicco, RL;Bassi, DE;Klein-Szanto, AJP
Furin是一种参与激活几种与癌症相关的底物的强有力的前蛋白转换酶，它是以非活性酶原的形式合成的，因此最大限度地减少了导致蛋白质不适当激活或降解的过早酶活性的发生。这种自然的抑制机制是基于酶原NH2末端存在一个失活的前段。在最初的自催化切割后，前段仍然与转换酶紧密结合，直到它到达反式高尔基网络，在那里发生前段的解离和Furin的激活。我们假设，如果在肿瘤细胞中异位表达，呋喃前体段(PpFur)的抑制特性可能是有益的。将ppFur全序列(pIRES-EGFP-ppFur)和空表达载体(pIRES-EGFP)分别导入4株人头颈部鳞癌细胞系。通过体内致瘤性、侵袭性、软琼脂中非锚定生长和增殖试验以及通过研究呋喃类物质加工的损害来评估其抑制效果。在体外和体内观察到，ppFur的细胞增殖、致瘤性和侵袭性显著降低。这些生物学变化直接与抑制Furin介导的关键癌症相关底物的激活有关，如膜型基质金属蛋白酶1、转化生长因子-β、胰岛素样生长因子-1受体和血管内皮生长因子-C。PpFur在头颈部鳞状细胞癌细胞系中的表达表明，抑制Furin、减少底物加工、细胞增殖和侵袭能力之间存在机制联系。这些发现表明，呋喃西林抑制是一种可行的方法来改善甚至取消各种恶性肿瘤的恶性表型。
Furin, a potent proprotein convertase involved in activation of several cancer-related substrates, is synthesized as an inactive zymogen, thus minimizing the occurrence of premature enzymatic activity that would lead to inappropriate protein activation or degradation. This natural inhibitory mechanism is based on the presence of an inactivating prosegment at the NH2 terminal of the zymogen. After initial autocatalytic cleavage, the prosegment remains tightly associated with the convertase until it reaches the trans-Golgi network where the dissociation of the prosegment and activation of furin occurs. We hypothesized that the inhibitory properties of the preprosegment of furin (ppFur) could be beneficial if ectopically expressed in tumor cells. Transfection of four human head and neck squamous cell carcinoma cell lines with the complete ppFur cDNA sequence (pIRES-EGFP-ppFur) or with the empty expression vector (pIRES-EGFP) was done. The inhibitory effect was evaluated using in vivo tumorigenicity, invasion, anchorage-independent growth in soft agar, and proliferation assays, as well as by investigating impairment of furin substrates processing. Following transfection of ppFur, a significant reduction in cell proliferation, tumorigenicity, and invasiveness was observed in vitro and in vivo. These biological changes are directly related to the inhibition of furin-mediated activation of crucial cancer-related substrates, such as membrane type 1 matrix metalloproteinase, transforming growth factor-beta, insulin-like growth factor-1 receptor, and vascular endothelial growth factor-C. PpFur expression in head and neck squamous cell carcinoma cell lines showed a mechanistic link between furin inhibition, decreased substrate processing, cell proliferation, and invasive ability. These findings suggest that furin inhibition is a feasible approach to ameliorate and even abolish the malignant phenotype of various malignancies.