A growth-suppressive function for the c-fes protein-tyrosine kinase in colorectal cancer
A growth-suppressive function for the c-fes protein-tyrosine kinase in colorectal cancer
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DOI：
10.1074/jbc.m507331200
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发表时间：
2006-03-31
影响因子：
4.8
通讯作者：
Smithgall, TE
中科院分区：
文献类型：
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作者：
Delfino, FJ;Stevenson, H;Smithgall, TE
人类c-fes基因座编码一种与骨髓、血管内皮和神经元细胞分化有关的非受体蛋白酪氨酸激酶。最近对结直肠癌中酪氨酸激酶组的分析确定c-fes是仅有的七个具有一致激酶结构域突变的基因之一。虽然鉴定了四个突变（M704 V、R706 Q、V743 M、S759 F），但未探索这些突变对Fes激酶活性的影响。为了解决这个问题，具有这些取代的Fes突变体与STAT 3在人293 T细胞中共表达。令人惊讶的是，与野生型Fes相比，M704 V、R706 Q和V743 M突变显著降低了Fes自身磷酸化和STAT 3 Tyr-705磷酸化，而S759 F几乎没有影响。这些突变对酵母表达系统中的Fes激酶活性具有类似的影响，表明它们通过影响激酶结构域结构来抑制Fes。我们还首次证明了内源性Fes在结肠隐窝的基部强烈表达，在那里它与祖细胞标记物Musashi-1阳性的上皮细胞共定位。与正常结肠上皮相比，Fes表达在大多数个体的结肠肿瘤切片中减少或不存在。在一组人结肠直肠癌细胞系中，包括HT-29和HCT 116细胞，Fes蛋白水平也很低或不存在。将Fes与重组逆转录病毒一起引入这些品系中抑制了它们在软琼脂中的生长。总之，我们的研究结果强烈暗示c-Fes蛋白酪氨酸激酶作为一个肿瘤抑制因子，而不是一个显性癌基因在结直肠癌。
The human c-fes locus encodes a non-receptor protein-tyrosine kinase implicated in myeloid, vascular endothelial, and neuronal cell differentiation. A recent analysis of the tyrosine kinome in colorectal cancer identified c-fes as one of only seven genes with consistent kinase domain mutations. Although four mutations were identified (M704V, R706Q, V743M, S759F), the consequences of these mutations on Fes kinase activity were not explored. To address this issue, Fes mutants with these substitutions were co-expressed with STAT3 in human 293T cells. Surprisingly, the M704V, R706Q, and V743M mutations substantially reduced Fes autophosphorylation and STAT3 Tyr-705 phosphorylation compared with wild-type Fes, whereas S759F had little effect. These mutations had a similar impact on Fes kinase activity in a yeast expression system, suggesting that they inhibit Fes by affecting kinase domain structure. We have also demonstrated for the first time that endogenous Fes is strongly expressed at the base of colonic crypts where it co-localizes with epithelial cells positive for the progenitor cell marker Musashi-1. In contrast to normal colonic epithelium, Fes expression was reduced or absent in colon tumor sections from most individuals. Fes protein levels were also low or absent in a panel of human colorectal cancer cell lines, including HT-29 and HCT 116 cells. Introduction of Fes into these lines with a recombinant retrovirus suppressed their growth in soft agar. Together, our findings strongly implicate the c-Fes protein-tyrosine kinase as a tumor suppressor rather than a dominant oncogene in colorectal cancer.