Cloning of the complete gene for carcinoembryonic antigen: analysis of its promoter indicates a region conveying cell type-specific expression.

Abstract

Carcinoembryonic antigen (CEA) is a widely used tumor marker, especially in the surveillance of colonic cancer patients. Although CEA is also present in some normal tissues, it is apparently expressed at higher levels in tumorous tissues than in corresponding normal tissues. As a first step toward analyzing the regulation of expression of CEA at the transcriptional level, we have isolated and characterized a cosmid clone (cosCEAl), which contains the entire coding region of the CEA gene. A close correlation exists between the exon and deduced immunoglobulin-like domain borders. We have determined a cluster of transcriptional starts for CEA and the closely related nonspecffic cross-reacting antigen (NCA) gene and have sequenced their putative promoters. Regions of sequence homology are found as far as approximately 500 nucleotides upstream from the translational starts of these genes, but farther upstream they diverge completely. In both cases we were unable to find classic TATA or CAAT boxes at their expected positions. To characterize the CEA and NCA promoters, we carried out transient transfection assays with promoter-indicator gene constructs in the CEA-producing adenocarcinoma cell line SW403, as well as in nonproducing HeLa cells. A CEA gene promoter construct, containing approximately 400 nucleotides upstream from the translational start, showed nine times higher activity in the SW403 than in the HeLa cell line. This indicates that cis-acting sequences which convey cell type-specific expression of the CEA gene are contained within this region.

Detection of colonic cells in peripheral blood of colorectal cancer patients by means of reverse transcriptase and polymerase chain reaction

“…and its expression is maintained in almost all colorectal carcinomas (Shively and Beatty, 1985). Its genomic organization (Schrewe et al, 1990) and cDNA sequence (Oikawa et al, 1987) are known. In addition, this target has been used in the specific detection of CEA-expressing tumour cells in bone marrow aspirates (Gerhard et al, 1994) and, recently, in the identification of circulating neoplastic cells in patients with colorectal liver metastasis (Jonas et al, 1996).…”

“…RT reaction was incubated at 42 C for 45 min followed by a 5-min period at 95"C to inactix-ate the rex erse transcriptase. CEA-specific oligonucleotide primers xere synthesized according, to published sequence information (Schrewe et al 1990):…”

In vitro evaluation of cancer-specific NF-κB-CEA enhancer–promoter system for 5-fluorouracil prodrug gene therapy in colon cancer cell lines

“…The CEA basal promoter sequences in this paper are numbered relative to the middle nucleotide of the first ATG (Schrewe et al, 1990). Two basal CEA promoter sequences (CEA205: À245 to À41 and CEA421: À421 to þ 1) were used to construct luciferase reporter vectors in combination with or without NF-kB enhancer elements.…”

The dominant negative H-ras mutant, N116Y, suppresses growth of metastatic human pancreatic cancer cells in the liver of nude mice

“…The 2.7 kb BglII-XbaI fragment containing the CEA promoter and N116Y cDNA was cloned into the BglII/XbaI digested pGL3-basic vector (Promega, Madison, WI, USA) to construct pGL3-CEA-N116Y. 26 The BglII-BglII fragment containing CEA promoter, N116Y cDNA, and SV40 polyadenylation signal was ligated with the BglII-BglII fragment containing the shuttle region of plasmid pCA 14 (Microbix Biosystems, Toronto, Canada) to construct pCA 14-CEA-N116Y. The shuttle plasmid, pCA 14-CEA-N116Y, and pJM 17 plasmid were cotransfected into the 293 transformed human embryonic kidney cells by calcium phosphate precipitation to generate replication-deficient adenovirus, Ad CEA-N116Y.…”

“…23,24 To accomplish selective expression of N116Y in tumor cells, we made an E1-deleted replicationdeficient recombinant adenovirus, Ad CEA-N116Y, in which N116Y cDNA was driven by a human carcinoembryonic antigen (CEA) promoter. 25,26 This construct is designed to express N116Y only in cells where the CEA promoter is active.…”