HSP60, a protein downregulated by IGFBP7 in colorectal carcinoma.
BACKGROUND
In our previous study, it was well defined that IGFBP7 was an important tumor suppressor gene in colorectal cancer (CRC). We aimed to uncover the downstream molecules responsible for IGFBP7's behaviour in this study.


METHODS
Differentially expressed protein profiles between PcDNA3.1(IGFBP7)-transfected RKO cells and the empty vector transfected controls were generated by two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) identification. The selected differentially expressed protein induced by IGFBP7 was confirmed by western blot and ELISA. The biological behaviour of the protein was explored by cell growth assay and colony formation assay.


RESULTS
Six unique proteins were found differentially expressed in PcDNA3.1(IGFBP7)-transfected RKO cells, including albumin (ALB), 60 kDa heat shock protein(HSP60), Actin cytoplasmic 1 or 2, pyruvate kinase muscle 2(PKM2), beta subunit of phenylalanyl-tRNA synthetase(FARSB) and hypothetical protein. The downregulation of HSP60 by IGFBP7 was confirmed by western blot and ELISA. Recombinant human HSP60 protein could increase the proliferation rate and the colony formation ability of PcDNA3.1(IGFBP7)-RKO cells.


CONCLUSIONS
HSP60 was an important downstream molecule of IGFBP7. The downregulation of HSP60 induced by IGFBP7 may be, at least in part, responsible for IGFBP7's tumor suppressive biological behaviour in CRC.
Ruan
Wenjing
W
Department of Pathology, School of Medicine, Zhejiang University, 388 Yuhangtang Road, Hangzhou 310058, Zhejiang Province, China.
Wang
Yinghong
Y
Ma
Yu
Y
Xing
Xiaoming
X
Lin
Jie
J
Cui
Jing
J
Lai
Maode
M
D015153:Blotting, Western; D002277:Carcinoma / Q000378:metabolism*; D049109:Cell Proliferation; D018834:Chaperonin 60 / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018969:Insulin-Like Growth Factor Binding Proteins / Q000096:biosynthesis*; D013058:Mass Spectrometry / Q000379:methods; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D018834:Chaperonin 60; D018969:Insulin-Like Growth Factor Binding Proteins; C102529:insulin-like growth factor binding protein-related protein 1