ENDOTHELIN-1 AND ET(A) RECEPTOR SUBTYPE ARE EXPRESSED IN THE GASTRIC HGT-1 CELL-LINE

Recent studies have revealed that endothelin-1 (ET-1) may be produced by human cancer cell lines and have suggested that in vivo the peptide might play a modulatory role in the growth of stromal cells surroundi ng tumor cells and/or in the growth of the cancer cells themselves, th rough paracrine or autocrine mechanisms. Therefore, we investigated wh ether ET-1 and ET receptors could be expressed in the human gastric ca ncer cell line HGT-1. By applying the reverse transcriptase polymerase chain reaction (RT-PCR) to total RNA extracted from the cells, using oligonucleotides synthesized from the sequence of the prepro-ET-1 mRNA , we have amplified a cDNA at the expected size (453 bp), which hybrid ized with a labeled ET-1-specific probe. In addition, RT-PCR was carri ed out to test whether HGT-1 cells expressed mRNA for ET(A) and/or ET( B) receptor subtypes. The amplified products of cDNA were at the size predicted for the ET(A) receptor (368 bp), whereas no ET(B) receptor m RNA could be detected.