Expression of neural BC1 RNA: induction in murine tumours.

BC1 RNA is a small cytoplasmic RNA polymerase III transcript that is expressed in the rodent nervous system. The RNA is selectively expressed in neurons where it is located in somatodendritic domains. BC1 RNA is not normally detectable in non-neuronal somatic cells; it is however expressed in germ cells and in cultured immortal cell lines of various non-neural origins. We therefore sought to establish whether the neuron-specific regulation of BC1 expression is altered in non-neural tumour cells. Oncogen and chemical carcinogen induced mouse tumours were analysed for the presence of BC1 RNA, using Northern transfer and in situ hybridisation. Here we report that BC1 RNA is selectively expressed in tumour cells, but not in corresponding normal tissues. These results indicate that neural-specific regulation of BC1 expression is lacking in murine tumour cells of non-neural origin.