Statin expression in the untreated and SarCNU-exposed human glioma cell line, SK-MG-1

Cytokinetic analyses of gliomas and other neoplasms rely exclusively on the use of proliferation-dependent markers such as [3H]-thymidine and BuDR incorporation and the detection of growth-dependent proteins such as proliferating cell nuclear antigen (PCNA) and Ki-67. In normal tissues, the monoclonal antibody S-44 recognizes statin, a nuclear protein expressed only in nonproliferating cells. In the present study, indirect immunofluorescence microscopy using S-44 identified nuclear statin in 5.9% of a population of untreated human SK-MG-1 glioma cells in vitro. Incremental doses of the alkylating agent sarcosinamide chloroethylnitrosourea (SarCNU) induced a linear increase in the fraction of statin-positive SK-MG-1 cells. Labeling of nuclear statin with the monoclonal antibody S-44 may be a potentially useful marker of the cytotoxic effects of anticancer drugs in gliomas and other neoplastic tissues.