title: POTE paralogs are induced and differentially expressed in many cancers.
abstract: To identify new antigens that are targets for the immunotherapy of prostate and breast cancer, we used expressed sequence tag and genomic databases and discovered POTE, a new primate-specific gene family. Each POTE gene encodes a protein that contains three domains, although the proteins vary greatly in size. The NH2-terminal domain is novel and has properties of an extracellular domain but does not contain a signal sequence. The second and third domains are rich in ankyrin repeats and spectrin-like helices, respectively. The protein encoded by POTE-21, the first family member discovered, is localized on the plasma membrane of the cell. In humans, 13 highly homologous paralogs are dispersed among eight chromosomes. The expression of POTE genes in normal tissues is restricted to prostate, ovary, testis, and placenta. A survey of several cancer samples showed that POTE was expressed in 6 of 6 prostate, 12 of 13 breast, 5 of 5 colon, 5 of 6 lung, and 4 of 5 ovarian cancers. To determine the relative expression of each POTE paralog in cancer and normal samples, we employed a PCR-based cloning and analysis method. We found that POTE-2alpha, POTE-2beta, POTE-2gamma, and POTE-22 are predominantly expressed in cancers whereas POTE expression in normal tissues is somewhat more diverse. Because POTE is primate specific and is expressed in testis and many cancers but only in a few normal tissues, we conclude POTE is a new primate-specific member of the cancer-testis antigen family. It is likely that POTE has a unique role in primate biology.
authors.affiliation: Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892-4264, USA.
authors.forename: Tapan K
authors.initials: TK
authors.lastname: Bera
authors.forename: Ashley
authors.initials: A
authors.lastname: Saint Fleur
authors.forename: Yoomi
authors.initials: Y
authors.lastname: Lee
authors.forename: Andre
authors.initials: A
authors.lastname: Kydd
authors.forename: Yoonsoo
authors.initials: Y
authors.lastname: Hahn
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Popescu
authors.forename: Drazen B
authors.initials: DB
authors.lastname: Zimonjic
authors.forename: Byungkook
authors.initials: B
authors.lastname: Lee
authors.forename: Ira
authors.initials: I
authors.lastname: Pastan
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D010920:Placenta / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013736:Testicular Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology
chemical_list: D009363:Neoplasm Proteins