Identification of a novel tumor transforming gene GAEC1 at 7q22 which encodes a nuclear protein and is frequently amplified and overexpressed in esophageal squamous cell carcinoma

• Published in: Oncogene Vol. 26; no. 40; pp. 5877 - 5888
• Main Authors: LAW, F. B. F, CHEN, Y. W, TSAO, S. W, LAM, K. Y, WONG, J, SRIVASTAVA, G, TANG, J. C. O, WONG, K. Y, YING, J, TAO, Q, LANGFORD, C, LEE, P. Y, LAW, S, CHEUNG, R. W. L, CHUI, C. H
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing 30-08-2007; Nature Publishing Group
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Cancer; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - metabolism; Cell Line, Tumor; Cell Nucleus - metabolism; Cell physiology; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cellular proteins; Chromosome 7; Chromosomes, Human, Pair 7; Diagnosis; DNA fingerprinting; DNA fingerprints; DNA testing; Esophageal cancer; Esophageal carcinoma; Esophageal Neoplasms - genetics; Esophageal Neoplasms - metabolism; Esophagus; Expressed sequence tags; Fibroblasts; Fundamental and applied biological sciences. Psychology; Gastroenterology. Liver. Pancreas. Abdomen; Gene expression; Gene Expression Regulation, Neoplastic; Genetic aspects; Genomics; H-Ras protein; Humans; Hybridization; Medical sciences; Mice; Mice, Nude; Models, Genetic; Molecular and cellular biology; Molecular Sequence Data; mRNA; Neoplasm Transplantation; Nuclear Proteins - biosynthesis; Nuclear Proteins - genetics; Physiological aspects; Proteins; Rodents; Sarcoma; Squamous cell carcinoma; Tumors; China; 7q22; esophageal cancer; Esophageal disease; Esophagus squamous cell carcinoma; Gene overexpression; Identification; Malignant tumor; Carcinogenesis; Esophagus cancer; Gene amplification; Gene; overexpression; Digestive diseases; Nuclear protein; transforming gene
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/sj.onc.1210390

By comparative DNA fingerprinting, we identified a 357-bp DNA fragment frequently amplified in esophageal squamous cell carcinomas (ESCC). This fragment overlaps with an expressed sequence tag mapped to 7q22. Further 5' and 3'-rapid amplification of cDNA ends revealed that it is part of a novel, single-exon gene with full-length mRNA of 2052 bp and encodes a nuclear protein of 109 amino acids ( approximately 15 kDa). This gene, designated as gene amplified in esophageal cancer 1 (GAEC1), was located within a 1-2 Mb amplicon at 7q22.1 identified by high-resolution 1 Mb array-comparative genomic hybridization in 6/10 ESCC cell lines. GAEC1 was ubiquitously expressed in normal tissues including esophageal and gastrointestinal organs; with amplification and overexpression in 6/10 (60%) ESCC cell lines and 34/99 (34%) primary tumors. Overexpression of GAEC1 in 3T3 mouse fibroblasts caused foci formation and colony formation in soft agar, comparable to H-ras and injection of GAEC1-transfected 3T3 cells into athymic nude mice formed undifferentiated sarcoma in vivo, indicating that GAEC1 is a transforming oncogene. Although no significant correlation was observed between GAEC1 amplification and clinicopathological parameters and prognosis, our study demonstrated that overexpressed GAEC1 has tumorigenic potential and suggest that overexpressed GAEC1 may play an important role in ESCC pathogenesis.