title: Expression of gastrointestinal endocrine tumours in culture systems.
abstract: Human endocrine tumours were studied in in vitro systems (cell suspensions and tissue cultures) and in in vivo systems (tumour transplants to the anterior eye-chamber of immunosuppressed rats). In the experimental systems the tumour cells were demonstrated to synthesize and secrete the same hormonal products as in the patient. Intraocular transplants of a gastrinoma secreted gastrin-17 into the chamber fluid. This molecule, normally not secreted in the rat, was also detected in the peripheral plasma of tumour-bearing rats. Intraocular transplants of midgut carcinoid tumours released serotonin (5-HT) at adrenoceptor stimulation, of a similar type as demonstrated in acute tumour cell suspensions. However, in tissue cultures genuine beta-adrenoceptors seemed to be modified, since pretreatment with beta-adrenoceptor antagonists or calcium deprivation did not prevent stimulated 5-HT release. Tachykinins were not liberated by adrenoceptor stimulation. In certain cultures of midgut carcinoid tumour cells, two different phenotypes developed: small rounded endocrine tumour cells with positive immunoreactions against 5-HT and tachykinins (TK), and large elongated neuron-like cells, which gradually lost 5-HT immunoreactivity, while TK immunoreactivity remained unchanged. These cultured tumour cells may produce an endogenous factor inducing transformation into a neuron-like phenotype. One candidate factor is nerve growth factor (NGF), since NGF-like immunoreactivity was demonstrated in cells of the endocrine phenotype.
authors.affiliation: Department of Surgery, University of Göteborg, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Ahlman
authors.forename: L
authors.initials: L
authors.lastname: Ahlund
authors.forename: A
authors.initials: A
authors.lastname: Dahlström
authors.forename: E
authors.initials: E
authors.lastname: Theodorsson
mesh_terms: D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D006801:Humans; D009474:Neurons / Q000166:cytology; D010641:Phenotype; D014407:Tumor Cells, Cultured / Q000473:pathology