title: The insulin-like growth factor receptor 1 is a promising target for novel treatment approaches in neuroendocrine gastrointestinal tumours.
abstract: Gastrointestinal neuroendocrine tumours (NET) represent a heterogeneous tumour entity. The anti-neoplastic therapy of advanced NET disease is still unsatisfactory and innovative therapeutic approaches are needed. As NET frequently express insulin-like growth factors (IGFs) and their receptors (IGFR), known to promote survival, oncogenic transformation, tumour growth and spreading, the inhibition of the IGF/IGF-receptor system may offer possibilities for novel targeted treatment strategies of NET. Here, we studied the anti-neoplastic effects of an inhibition of the IGF-I receptor (IGF-1R) signalling in NET cells by the novel IGF-1R tyrosine kinase (TK) inhibitor NVP-AEW541, whose anti-neoplastic potency has not yet been tested in NET disease. Using two human NET cell lines with different growth characteristics, we demonstrated that NVP-AEW541 dose-dependently inhibited the proliferation of NET cells by inducing apoptosis and cell cycle arrest. Anti-neoplastic effects of NVP-AEW541 were also detected in primary cultures of human neuroendocrine gastrointestinal tumours. Apoptosis was characterized by activation of the apoptotic key enzyme, caspase-3, as well as by detection of changes in the expression of the pro- and anti-apoptotic proteins, BAX and Bcl-2, after NVP-AEW541 treatment. Cell cycle was arrested at the G1/S checkpoint. The anti-neoplastic effects of NVP-AEW541 involved the inactivation of ERK1/2. Induction of immediate cytotoxicity did not account for the anti-neoplastic effects of NVP-AEW541, as shown by measurement of lactate dehydrogenase release. Moreover, additive anti-neoplastic effects were observed when NVP-AEW541 was combined with cytostatics such as doxorubicin or the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, fluvastatin. This is the first report on the induction of apoptosis and cell cycle arrest by the IGF-1R-TK inhibitor, NVP-AEW541, in NET cells. The inhibition of the IGF/IGFR system appears to be a promising novel approach for future treatment strategies of NET disease.
authors.affiliation: Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Medical Clinic I, Gastroenterology/Infectious Diseases/Rheumatology, Hindenburgdamm 30, 12200 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Höpfner
authors.forename: Viola
authors.initials: V
authors.lastname: Baradari
authors.forename: Alexander
authors.initials: A
authors.lastname: Huether
authors.forename: Christof
authors.initials: C
authors.lastname: Schöfl
authors.forename: Hans
authors.initials: H
authors.lastname: Scherübl
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology; D004338:Drug Combinations; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D000077340:Fluvastatin; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D018358:Neuroendocrine Tumors / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011743:Pyrimidines / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D017526:Receptor, IGF Type 1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
chemical_list: D000903:Antibiotics, Antineoplastic; D004338:Drug Combinations; D005229:Fatty Acids, Monounsaturated; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007211:Indoles; C501177:NVP-AEW541; D011743:Pyrimidines; D011758:Pyrroles; D000077340:Fluvastatin; D004317:Doxorubicin; D007770:L-Lactate Dehydrogenase; D017526:Receptor, IGF Type 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases