INFLUENCE OF EPIDERMAL GROWTH-FACTOR AND GASTRIN ON THE CELL-PROLIFERATION OF HUMAN MENINGIOMAS VERSUS ASTROCYTIC TUMORS MAINTAINED AS EX-VIVO TISSUE-CULTURES

The hormone sensitivity of a tumor is traditionally based on the prese nce of steroid receptors. Other factors should be taken into considera tion. Here, we studied the influence of 10 nM epidermal growth factor (EGF) or gastrin on the proliferation of human ex vivo tumor cultures by means of [H-3]thymidine autoradiography. The immunohistochemical EG F-receptor expression was also quantified by means of computer-assiste d microscopy. The results demonstrated that the proliferation of 6/11 astrocytic tumors and 3/16 meningiomas was sensitive to at least one f actor tested, i.e. EGF or gastrin (P < 0.01), and 5 of these 9 'hormon e-sensitive' tumors were sensitive to both factors. The immunohistoche mical labeling index for the EGF receptor was higher than 80% in 15/16 meningiomas, but only in 6/11 gliomas (P < 0.01). These results sugge st that EGF and gastrin are important for astrocytic tumor proliferati on and significantly (P < 0.01) less important for meningiomas. Thus, astrocytic tumors may be steroid insensitive in term of cell growth, b ut are certainly not hormone insensitive.