In vitro sensitivity of nitrosourea-induced neurogenic tumors to ACNU.

The effect of ACNU on the in vitro viability of a methylnitrosourea-induced gliosarcoma (T9) and two ethylnitrosourea-induced brain tumors, TR-481 (a malignant neurinoma) and EB-679 (a glioma) was studied. T9 was highly sensitive to ACNU, demonstrating loss of cells following a 3 hour exposure time to 5 microgram/ml; TR-481 was sensitive to 40 microgram/ml of ACNU and EB-679 was highly resistant to 40 microgram/ml of ACNU. The in vitro sensitivity of the tumor cell lines to ACNU is: T 9 greater than TR-481 greater than EB-679. This data indicates that variability of response to both concentration and exposure time of ACNU of malignant brain tumor cells must be taken into consideration in planning in vitro and/or in vivo treatment of experimental brain tumors.