C-CAM1 expression: Differential effects on morphology, differentiation state and suppression of human PC-3 prostate carcinoma cells

Two Variable Regions in Carcinoembryonic Antigen-related Cell Adhesion Molecule1 N-terminal Domains Located in or Next to Monoclonal Antibody and Adhesion Epitopes Show Evidence of Recombination in Rat but Not in Human

“…The Ceacam10 and RER N-domainenriched ligation mixtures used to transform competent INV␣FЈ cells and plasmid DNAs from recombinant white colonies were screened by RE digest and PCR/RE assays. The authenticity of the Ceacam1 a and Ceacam10 N-domain inserts and the sequence of the unique RER Ndomain inserts were confirmed by automated sequencing as described previously (19), using the following vector specific primers: forward SP6 primer (5Ј-CTATTTAGGTGACACTATAG-3Ј) and a reverse T7 promoter primer (5Ј-TAATACGACTCACTATAGGG-3Ј). Automated sequence readouts were transferred into the MacVector program for MacIntosh and were aligned with the known sequences of the Ceacam1 a , -1 b and -10 N-domains.…”

“…Liver samples were obtained from Japanese Fischer 344 males (Charles River, Japan), American Fischer F344 males (Charles River, Wilmington, DE), and German Fischer 344 males selected from a colony maintained at Rhode Island Hospital that was initiated with breeder pairs obtained from Charles River, Germany; ACI and Sprague-Dawley males were from Harlan Sprague-Dawley, Indianapolis, IN. RT-PCR on 1 g of total RNA was performed as described previously (19) by using random hexamers (PerkinElmer Life Sciences) in the RT step and the following Ceacam1 a N-domain primers in the amplification step as follows: 1) 5Ј-UTR/Sig 5Ј-CAGGCAGCAGAGACTATGGAGCTA-3Ј (nucleotides Ϫ14 -9) and 2) D2AS 5Ј-GGGATTGGAGTTGTTACCTGTGA-C-3Ј (nucleotides 445-468). Control templates for the PCR included 20 g of pCDM8 plasmid carrying either the Ceacam1 a -4L or Ceacam1 b -4S cDNAs.…”

“…The AML-12 cell line was kindly provided by Dr. Nelson Fausto, University of Washington, Seattle, WA. The construction of the retroviral expression plasmid LNCL containing the Ceacam1 a -4L cDNA has been described previously (19). Another retroviral expression plasmid, LNCS, containing the Ceacam1 b -4S cDNA was also constructed for these experiments (19).…”

“…The major splice variants in rodents and humans have from 2 to 4 Ig-like domains and cyto domains with either 70 -71 (L forms) or 9 -10 amino acids (S forms) (1-3, 5, 6). In rodents, allelic variants (Ceacam1 a and 1 b ) 2 or separate genes differing in both the nucleotide and amino acid sequence of their N-terminal Ig domains (rats and mice) have also been described (1, 13).Interest in the role of CEACAM1 in cancer has blossomed since early reports showed that this gene was lost or greatly down-regulated in rodent hepatocellular carcinomas (4 -16) and colon carcinomas (13,17,18) and that restoration of CEACAM1-4L expression in human prostate (19,20), mouse colon (21, 22), or human bladder carcinomas (23) produced a marked decrease or loss of tumorigenicity. Relatively recent studies have also shown that the ectodomain is not required for tumor suppression; the CEACAM1 a -4L cyto domain is necessary and sufficient for inhibiting tumorigenicity (24).…”

“…Interest in the role of CEACAM1 in cancer has blossomed since early reports showed that this gene was lost or greatly down-regulated in rodent hepatocellular carcinomas (4 -16) and colon carcinomas (13,17,18) and that restoration of CEACAM1-4L expression in human prostate (19,20), mouse colon (21,22), or human bladder carcinomas (23) produced a marked decrease or loss of tumorigenicity. Relatively recent studies have also shown that the ectodomain is not required for tumor suppression; the CEACAM1 a -4L cyto domain is necessary and sufficient for inhibiting tumorigenicity (24).…”