Isolation and characterization of PAGE-1 and GAGE-7. New genes expressed in the LNCaP prostate cancer progression model that share homology with melanoma-associated antigens.
The LNCaP progression model of human prostate cancer consists of lineage-related sublines that differ in their androgen sensitivity and metastatic potential. A differential display polymerase chain reaction was employed to evaluate mRNA expression differences between the LNCaP sublines in order to define the differences in gene expression between the androgen-sensitive, nontumorigenic LNCaP cell line and the androgen-insensitive, metastatic LNCaP sublines, C4-2 and C4-2B. An amplicon, BG16.21, was isolated that showed increased expression in the androgen-independent and metastatic LNCaP sublines, C4-2 and C4-2B. Hybridization screening of a lambda gt11 expression library with BG16.21 revealed two transcripts, both homologous to BG16.21 at the 3' end. A GenBankTM data base search using the GCG Wisconsin software package revealed the shorter approximately 600-bp transcript (designated GAGE-7) to be a new member of the GAGE family. The second approximately 700-bp transcript was a novel gene (designated PAGE-1, "prostate associated gene") with only 45% homology to GAGE gene family members. RNA blot analysis demonstrated that GAGE-7 mRNA was expressed at equal levels in all lineage related prostate cancer cell sublines, while PAGE-1 mRNA levels were elevated 5-fold in C4-2 and C4-2B as compared with LNCaP cells. Neither GAGE-7 nor PAGE-1 demonstrated any regulation by androgens in the prostate cancer cell lines used in this study. PAGE-1 and GAGE-7 expression was found to be restricted to testes (high) and placenta (low) on human multiple tissue Northern blots. As GAGE/MAGE antigens were reported previously to be targets for tumor-specific cytotoxic lymphocytes in melanoma, these results suggest that PAGE-1 and GAGE-7 may be related to prostate cancer progression and may serve as potential targets for novel therapies.
Chen
M E
ME
University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Lin
S H
SH
Chung
L W
LW
Sikes
R A
RA
D000595:Amino Acid Sequence; D000951:Antigens, Neoplasm / Q000235:genetics*; D001483:Base Sequence; D018076:DNA, Complementary; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D018076:DNA, Complementary; C113434:GAGE7 protein, human; D009363:Neoplasm Proteins; C113433:PAGE1 protein, human