TRKA EXPRESSION DECREASES THE IN-VIVO AGGRESSIVENESS OF C6 GLIOMA-CELLS

We stably expressed the nerve growth factor receptor trkA or a truncat ed trkA lacking the kinase domain (trkA Delta) in a highly tumorigenic rat glioma cell line, C6. Survival of rats with large intrastriatal i nocula of C6(trkA) cells was significantly longer than for rats bearin g C6 or C6(trkA Delta) cells, Histological studies revealed that C6(tr kA) cells were much less invasive than C6 or C6(trkA Delta) cells and had a greater rate of apoptosis, There was no apparent induction of di fferentiation of C6 cells by trkA. Therefore, unlike what is observed in neuroblastomas, trkA decreases tumorigenicity by modulating invasiv eness and tumor cell death independent of inducing differentiation. Th is novel mechanism suggests a new therapeutic strategy for malignant g liomas.