Keratin 17 identified by proteomic analysis may be involved in tumor angiogenesis.
Angiogenesis is crucial for solid tumor growth. By secreting angiogenic factors, tumor cells induce angiogenesis. However, targeting these angiogenic factors for cancer therapy is not always successful, suggesting that other factors may be involved in tumor angiogenesis. This work shows that 25 protein spots were differentially expressed by two-dimensional gel electrophoretic analysis when HepG2 cells induced endothelial cell differentiation to tube in vitro, and most of them were upregulated. Twenty-one proteins were identified with MALDI-TOF-MS, and the other four were identified by LTQ-MS/MS. Keratins were identified as one class of these upregulated proteins. Further study indicated that the expression of keratin 17 in cultured endothelial cells is likely microenvironment regulated, because its expression can be induced by HepG2 cells and bFGF as well as serum in culture media. Increased expression of keratins in endothelial cells, such as keratin 17, may contribute to the angiogenesis induced by HepG2 cells.
Xu
Yong
Y
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School and School of Life Science, Sichuan University, Chengdu, 610041, P. R. China.
Zhang
Su-Zhen
SZ
Huang
Can-Hua
CH
Liu
Xin-Yu
XY
Zhong
Zhen-Hua
ZH
Hou
Wen-Li
WL
Su
Zi-Fen
ZF
Wei
Yu-Quan
YQ
D002478:Cells, Cultured; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000378:metabolism; D006801:Humans; D053537:Keratin-17 / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology*; D009369:Neoplasms / Q000098:blood supply* / Q000235:genetics / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods
D053537:Keratin-17