We investigated the effects of the potent somatostatin analog RC-160 on the growth of human osteosarcoma cell lines SKE-ES-1 and MNNG/HOS, transplanted into nude mice or cultured in vitro. Growth of SK-ES-1 and MNNG/HOS tumors in nude mice was significantly inhibited after 4 weeks of treatment with daily s.c. injections of 100 μg RC-160, as measured by a reduction in tumor volume and weight. Histologically, the number of mitotic cells was decreased in the groups treated with RC-160. In mice bearing either tumor model, administration of RC-160 significantly decreased serum growth hormone and insulin-like growth factor I (IGF-I) levels. Specific high-affinity receptors for somatostatin and epidermal growth factor were found on membranes of MNNG/HOS tumors but not on SK-ES-1 tumors. Receptor analyses also demonstrated high-affinity binding sites for IGF-I on membranes of both tumors. In cell cultures, the proliferation rate of MNNG/HOS cells, but not of SK-ES-1, was significantly suppressed by RC-160. Our findings demonstrate that RC-160 can significantly inhibit the growth of SK-ES-1 and MNNG/HOS osteosarcomas in mice.
|Original language||English (US)|
|Number of pages||5|
|Journal||International Journal of Cancer|
|State||Published - Mar 15 1996|
ASJC Scopus subject areas
- Cancer Research