c-peptide and Hemangiopericytoma

Haemangiopericytoma is a rare soft tissue tumour originating from the contractile pericapillary cells. Relatively little is known about its molecular pathogenesis. To address this issue, the insulin-like growth factor family (IGFs) was analysed in 19 tumours collected from a human tumour bank network. Seven of the tumours were associated with severe hypoglycaemia. Of these, six were retroperitoneal and one was located in the leg. 3 out of the 19 tumours (15.8 per cent) were positive for insulin-like growth factor I (IGF I) mRNA and 11 were positive for IGF II mRNA (57.9 per cent). Almost 90 per cent of haemangiopericytomas expressed IGF I receptor (IGF IR) mRNA (17 out of 19), five (26.3 per cent) expressed IGF binding protein 1 (IGF BP1), three (15.8 per cent) expressed IGF BP2, and four (21 per cent) exhibited IGF BP3 mRNA. All of the 14 haemangiopericytomas examined with regard to specific receptor binding were IGF IR positive, ranging from 1.2 to 16.2 per cent. Binding was much higher in IGF I/IGF IR positive tumours (15.3+/-0. 7) than in IGF I negative/IGF IR positive tumours (5.1+/-3.3). The potential role of IGF IR as a growth promoting factor in malignant haemangiopericytoma was studied using antisense oligonucleotides and monoclonal antibody alphaIR3 that specifically inhibit IGF IR synthesis or activity. 10 microM IGF IR antisense oligonucleotides significantly inhibited the growth of haemangiopericytoma cells in culture, by around 50 per cent; monoclonal antibody against IGF IR (alphaIR3) also significantly inhibited proliferation. The data suggest that IGF IR may play an important role in the genesis and progression of malignant haemangiopericytomas.

Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; C-Peptide; Cell Division; Child, Preschool; Female; Hemangiopericytoma; Humans; Hypoglycemia; Insulin; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Lung Neoplasms; Male; Middle Aged; Pelvic Neoplasms; Receptor, IGF Type 1; Retroperitoneal Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Somatomedins; Tumor Cells, Cultured

We have studied a patient with fasting hypoglycaemia and skin lesions (sign of Leser-Trélat) related to a retroperitoneal haemangiopericytoma in whom removal of the tumour resulted in immediate cure of hypoglycaemia. Before removal of the tumour, severe fasting hypoglycaemia was associated with undetectable insulin and C-peptide levels. She required 16.9 mumol/kg/min (10.4 g/h) of glucose intravenously to prevent hypoglycaemia and endogenous glucose production (measured using tritiated glucose) was suppressed to 1.3 mumol/kg/min while the whole-body glucose utilization rate was elevated at 18.2 mumol/kg/min. After removal of the tumour both endogenous glucose production rate and utilization rate returned to normal (11.5 mumol/kg/min). Resting energy expenditure, measured by indirect calorimetry, was markedly elevated at 2109 kcal/day (161% of predicted) and fell to 1205 (97% of predicted) after the tumour was removed. Glucose oxidation was also enhanced at 8.5 mumol/kg/min and fell to 3.3 mumol/kg/min after removal of the tumour. Other metabolites and hormones measured, and their response to oral glucose, were all consistent with the presence of a circulating substance with similar properties to insulin. We conclude that her hypoglycaemia resulted primarily from suppression of endogenous glucose production but also from enhanced glucose utilization. These effects were the result of a circulating growth factor sharing many metabolic effects with insulin, but with a much greater effect on resting energy expenditure and glucose oxidation.

Topics: Adult; Blood Glucose; C-Peptide; Calorimetry; Carbon Dioxide; Female; Hemangiopericytoma; Humans; Hypoglycemia; Insulin; Oxygen Consumption; Peritoneal Neoplasms

Tumor growth in a 72-year-old male patient with malignant haemangiopericytoma in the left hemithorax could be followed radiologically for 4 years before symptoms of recurrent hypoglycaemia appeared. The endogenous insulin level in serum was maximally and serum IGF-1 and IGF-2 markedly reduced. An intravenous arginine load test showed a normal stimulation capacity of the pancreatic glucagon secretion but not that of insulin. After resection of the tumor, blood sugar metabolism was completely normalised. The insulin level, IGF-1 and IGF-2 in serum returned to normal.

Topics: Aged; Arginine; C-Peptide; Glycated Hemoglobin; Hemangiopericytoma; Humans; Hypoglycemia; Male; Radiography, Thoracic; Thoracic Neoplasms