GENE-EXPRESSION OF SOMATOSTATIN RECEPTOR SUBTYPES, SSTR1 AND SSTR2, IN HUMAN LUNG-CANCER CELL-LINES

Somatostatin(SS) acts as a universal endocrine off-swich, and also inh ibits the growth of neuroendocrine tumors through its specific recepto rs. Small cell lung cancer (SCLC) demonstrates some neuroendocrine cha racteristics and has been proposed as a candidate for treatment with S S and its analogues. In the present study, we investigated the express ion of somatostatin receptor (SSTR) subtype (SSTR1 and SSTR2) mRNA in various human lung cancer cell lines by the sensitive reverse-transcri ption-PCR method and Southern blotting. The levels of expression of SS TR1 mRNA were higher in both SCLC and squamous cell carcinoma than in adenocarcinoma cell lines. Interestingly, SSTR1 gene expression was in dependent of that of SSTR2 in each SCLC cell line, although the expres sion of both genes showed a positive correlation in non-SCLC cells. Me mbranes from a cell line exhibiting highest expression of SSTR2 gene b ound SS and its analogue, octreotide, with moderate affinity. These fi ndings may provide useful information for the future clinical applicat ion of SS and its analogues for the treatment of lung cancer.