Identification of tumor-associated antigens by large-scale analysis of genes expressed in human colorectal cancer.
Despite the high prevalence of colon cancer in the world and the great interest in targeted anti-cancer therapy, only few tumor-specific gene products have been identified that could serve as targets for the immunological treatment of colorectal cancers. The aim of our study was therefore to identify frequently expressed colon cancer-specific antigens. We performed a large-scale analysis of genes expressed in normal colon and colon cancer tissues isolated from colorectal cancer patients using massively parallel signal sequencing (MPSS). Candidates were additionally subjected to experimental evaluation by semi-quantitative RT-PCR on a cohort of colorectal cancer patients. From a pool of more than 6000 genes identified unambiguously in the analysis, we found 2124 genes that were selectively expressed in colon cancer tissue and 147 genes that were differentially expressed to a significant degree between normal and cancer cells. Differential expression of many genes was confirmed by RT-PCR on a cohort of patients. Despite the fact that deregulated genes were involved in many different cellular pathways, we found that genes expressed in the extracellular space were significantly over-represented in colorectal cancer. Strikingly, we identified a transcript from a chromosome X-linked member of the human endogenous retrovirus (HERV) H family that was frequently and selectively expressed in colon cancer but not in normal tissues. Our data suggest that this sequence should be considered as a target of immunological interventions against colorectal cancer.
Alves
Pedro M S
PM
National Center of Competence in Research, Molecular Oncology, ISREC, Ch. des Boveresses 155, 1066 Epalinges, Switzerland.
Lévy
Nicole
N
Stevenson
Brian J
BJ
Bouzourene
Hanifa
H
Theiler
Grégory
G
Bricard
Gabriel
G
Viatte
Sebastien
S
Ayyoub
Maha
M
Vuilleumier
Henri
H
Givel
Jean-Claude R
JC
Rimoldi
Donata
D
Speiser
Daniel E
DE
Jongeneel
C Victor
CV
Romero
Pedro J
PJ
Lévy
Frédéric
F
D000951:Antigens, Neoplasm / Q000032:analysis / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D015536:Down-Regulation; D020077:Endogenous Retroviruses / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C030139:colon-specific antigen