CRIPTO3, a presumed pseudogene, is expressed in cancer.
Cripto is a cell surface protein highly expressed in certain solid tumors, and overexpression of Cripto protein is oncogenic. Cripto-1 protein is encoded by CRIPTO1 gene. CRIPTO3, a presumed pseudogene, has an open reading frame with six amino acid differences from Cripto-1. We show that CRIPTO3 mRNA is the CRIPTO message expressed in many cancer samples. A CRIPTO3 SAGE tag was found in several cancer SAGE libraries, while the CRIPTO1 tag was found in ES cell libraries. In vitro experiments indicate both Cripto-1 and Cripto-3 proteins are functional in the Nodal-dependent signal pathway. Our data indicate that CRIPTO3 is an expressed gene, particularly in certain cancers, and suggest a potentially novel mechanism of oncogenesis through activation of a retrogene.
Sun
Chao
C
Department of Drug Discovery, Biogen Idec Inc, 14 Cambridge Center, Cambridge, MA 02142, USA. chao.sun@biogenidec.com
Orozco
Olivia
O
Olson
Dian L
DL
Choi
Eugene
E
Garber
Ellen
E
Tizard
Rich
R
Szak
Suzanne
S
Sanicola
Michele
M
Carulli
John P
JP
D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D004815:Epidermal Growth Factor / Q000235:genetics*; D058851:GPI-Linked Proteins; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics*; D011544:Pseudogenes; D014158:Transcription, Genetic
D058851:GPI-Linked Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C070636:TDGF1 protein, human; D004815:Epidermal Growth Factor