Biochemical characterization of riboflavin carrier protein (RCP) in prostate cancer.
Riboflavin carrier protein (RCP) is a growth- and development-specific protein. Here, we characterized the expression of this protein in prostate cancer by polyclonal and monoclonal antibodies against chicken RCP. RCP was localized to both androgen-dependent and independent prostate cancer cell lines. Compared to controls, RCP was over-expressed in all 45 prostate adenocarcinomas, irrespective of the Gleason's score or the stage of the disease. The identified RCP had a molecular weight of 38 kDa, similar to RCP purified from chicken. Presence of this protein was also confirmed by siRNA inhibition analysis. Antibodies to chicken RCP inhibited incorporation of tritiated thymidine into DNA and prevented riboflavin uptake in PC3 prostate cancer cells, suggesting a critical function of this protein in prostate cancer cell growth. These data suggest that RCP can be used as a tumor biomarker in prostate cancer.
Johnson
Tanya
T
Department of Biochemistry, Louisiana State University Health Sciences Center, New Orleans, LA, USA.
Ouhtit
Allal
A
Gaur
Rajiv
R
Fernando
Augusta
A
Schwarzenberger
Paul
P
Su
Joseph
J
Ismail
Mohamed F
MF
El-Sayyad
Hassan I
HI
Karande
Anjali
A
Elmageed
Zakaria Abd
ZA
Rao
Prakash
P
Raj
Madhwa
M
D000595:Amino Acid Sequence; D015153:Blotting, Western; D045744:Cell Line, Tumor; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D008297:Male; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D034741:RNA, Small Interfering; D012256:Riboflavin / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism
D026901:Membrane Transport Proteins; D034741:RNA, Small Interfering; C019079:riboflavin-binding protein; D012256:Riboflavin; D013936:Thymidine