Production of calcitonin gene-related peptide from human cancer cells.
Calcitonin (CT) is produced ectopically from a variety of non-thyroidal cancers. The CT genes also encode another peptide, calcitonin gene-related peptide (CGRP) which is a potent vasodilator. In the present study we have used immunochemical and chromatographic methods to demonstrate the presence and characterize the molecular forms of CGRP in cultured human cancer cells. Using two highly sensitive and specific radioimmunoassays, we have detected immunoreactive CGRP (i-CGRP) in cell extracts and cell-exposed media of cultured promyelocytic leukaemia (HL60) and bronchogenic carcinoma (BEN) cells. The mean i-CGRP content of the HL60 and BEN cell extracts was 2 and 45 pmol/g wet weight respectively. On gel filtration and high performance liquid chromatography, the immunoreactive material was found to be heterogeneous, though a major proportion co-eluted with synthetic human CGRP(1-37), suggesting structural identity with the intact CGRP molecule. Finally, we have discussed some interesting features of CT-gene peptide expression in tumour cells.
Zaidi
M
M
Department of Chemical Pathology, Royal Postgraduate Medical School, Hammersmith Hospital, London.
Breimer
L H
LH
MacIntyre
I
I
D002116:Calcitonin / Q000096:biosynthesis*; D015740:Calcitonin Gene-Related Peptide / Q000096:biosynthesis*; D002283:Carcinoma, Bronchogenic / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism*; D011863:Radioimmunoassay; D014407:Tumor Cells, Cultured / Q000378:metabolism
D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide