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Identification of a potential tumor differentiation factor receptor candidate in prostate cancer cells
Author(s) -
Sokolowska Izabela,
Woods Alisa G.,
Gawinowicz Mary Ann,
Roy Urmi,
Darie Costel C.
Publication year - 2012
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2012.08641.x
Subject(s) - du145 , lncap , prostate cancer , cancer research , cancer cell , biology , receptor , cancer , microbiology and biotechnology , biochemistry , genetics
Tumor differentiation factor (TDF) is a pituitary protein that is secreted into the bloodstream and has an endocrine function. TDF and TDF‐P1, a 20‐residue peptide selected from the ORF of TDF, induce differentiation in human breast and prostate cancer cells, but not in other cells. TDF has no known mechanism of action. In our recent study, we identified heat shock 70 kDa proteins (HSP70s) as TDF receptors (TDF‐Rs) in breast cancer cells. Therefore, we sought to investigate whether TDF‐R candidates from prostate cancer cells are the same as those identified in breast cancer cells. Here, we used TDF‐P1 to purify the potential TDF‐R candidates by affinity purification chromatography from DU145 and PC3 steroid‐resistant prostate cancer cells, LNCaP steroid‐responsive prostate cancer cells, and nonprostate NG108 neuroblastoma and BLK CL.4 fibroblast‐like cells. We identified the purified proteins by MS, and validated them by western blotting, immunofluorescence microscopy, immunoaffinity purification chromatography, and structural biology. We identified seven candidate proteins, of which three were from the HSP70 family. These three proteins were validated as potential TDF‐R candidates in LNCaP steroid‐responsive and in DU145 and PC3 steroid‐resistant prostate cancer cells, but not in NG108 neuroblastoma and BLK CL.4 fibroblast‐like cells. Our previous study and the current study suggest that GRP78, and perhaps HSP70s, are strong TDF‐R candidates, and further suggest that TDF interacts with its receptors exclusively in breast and prostate cells, inducing cell differentiation through a novel, steroid‐independent pathway. Structured digital abstract• TDF‐P1 physicallyinteracts with GRP78 and HSP70 by pulldown ( Viewinteraction ) • GRP78 binds to TDF‐P1 by antibaitcoimmunoprecipitation ( Viewinteraction ) • TDF‐P1 physicallyinteracts with GRP78 , HSP8 , HSP70 , HSP90‐beta , Sequestosome1 and valosin‐containing‐protein by pulldown ( Viewinteraction )