Expression of somatostatin messenger RNA and receptor in cultured brain tumor cells.

In order to understand the role of somatostatin in tumor cell growth, the expression of somatostatin in 7 cultured brain tumor cells was investigated. Radioimmunoassay demonstrated the production of somatostatin into the culture supernatant of 6 tumor cells. The expression of somatostatin mRNA and receptor was investigated by reverse transcription polymerase chain reaction (RT-PCR) and a binding assay with 125I-somatostatin-14, respectively. Only two cell lines, GBS-1 and U87MG, expressed somatostatin mRNA, whereas somatostatin receptor was expressed in all cultured cells. These results suggest that somatostatin is an important factor for regulating cell growth.