title: Small cell carcinoma cell lines contain opioid peptides and receptors.
abstract: Two human small cell carcinoma cell lines were assayed for total opioid and beta-endorphin-like immunoreactivity. Small cell carcinoma cell line NCI-H146 contained approximately 1.1 pmol/mg protein of total opioid immunoreactivity. This material was similar in size and immunoreactive determinants to C-terminally modified beta-endorphin. Small cell carcinoma cell line NCI-H187 contained approximately 0.2 pmol/mg protein total opioid immunoreactivity, which was of low molecular weight. NCI-H187 also contained approximately 1.2 pmol/mg protein of material similar in size and immunoreactive determinants to beta-lipotropin. The two small cell carcinoma cell lines were also examined for opioid receptors with the use of [3H]-etorphine as ligand. Both cell lines contained between 50 and 100 fmol/mg protein of specific, saturable, high-affinity opioid receptor binding sites. Together, these findings suggest a possible autocrine role for opioids in small cell carcinoma of the lung.
mesh_terms: D018288:Carcinoma, Small Cell / Q000032:analysis*; D002460:Cell Line; D004723:Endorphins / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D005048:Etorphine / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000032:analysis*; D011957:Receptors, Opioid / Q000032:analysis* / Q000502:physiology; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D011957:Receptors, Opioid; D005048:Etorphine; D001615:beta-Endorphin