Insulin-like growth factors are potent mitogenic factors in human lung cancer in vitro, acting via specific receptors. Using monoclonal antibodies we demonstrate the expression of insulin-like growth factor receptor I in bronchial epithelial cells of normal lung and in primary lung cancer (22/24 cases), being most prominent in squamous cell carcinoma. Electron microscopy on lung cancer cell lines reveals a distinct reaction pattern on the plasma membrane. Immunoreaction with a specific antibody directed against the insulin-like growth factor receptor II suggests a weak expression in primary lung cancer. Our findings underline the significance of the autocrine pathway of insulin-like growth factors in lung cancer.

No abstract

Intercellular adhesion molecule-1 (ICAM-1) expression correlates with tumour progression in patients with malignant melanoma or renal cell carcinoma. To assess the value of soluble ICAM-1 (sICAM-1) for lung cancer patients, sICAM-1 was determined by means of an enzyme-linked immunosorbent assay. Sera from 147 patients with lung cancer, from 75 patients with benign lung diseases and from 108 healthy adults were investigated for sICAM-1 expression. Significant differences in sICAM-1 levels were detected in lung cancer patients (387 +/- 176 ng/ml) and patients with benign lung diseases (365 +/- 110 ng/ml) compared to the group of healthy adults (310 +/- 90 ng/ml). There was no difference in sICAM-1 level among the subtypes of lung cancer. Advanced tumour stages and patients with progressive disease tended to be associated with higher sICAM-1 levels, the site of metastasis being relevant for the level attained. Patients with liver metastasis had the highest sICAM-1 levels (547 +/- 295 ng/ml) compared to patients with cerebral metastasis (317.8 +/- 92.2 ng/ml). An increase of sICAM-1 expression during the progression of the disease coincided with a poorer survival prognosis for the patients compared to patients with stable or falling sICAM-1 levels.

No abstract

Clear cell RCCs exhibit a complex and heterogeneous expression pattern for various growth factors and their receptors. Growth factor secretion and intact signal transduction pathways in most clear cell RCCs facilitate an intricate modulation of RCC growth by autocrine and paracrine interactions between tumor cells and host tissue.