Expression of urotensin II and urotensin II receptor mRNAs in various human tumor cell lines and secretion of urotensin II-like immunoreactivity by SW-13 adrenocortical carcinoma cells.

Urotensin II is the most potent vasoconstrictor peptide identified so far. Expression of urotensin II and urotensin II receptor mRNAs was studied in various human tumor cell lines by reverse transcriptase polymerase chain reaction (PCR) method. Secretion of urotensin II by these tumor cells was studied by radioimmunoassay. The tumor cell lines studied were T98G glioblastoma cells, IMR-32 neuroblastoma cells, NB69 neuroblastoma cells, BeWo choriocarcinoma cells, SW-13 adrenocortical carcinoma cells, DLD-1 colorectal adenocarcinoma cells and HeLa cervical cancer cells. Urotensin II mRNA was expressed in 6 tumor cell lines except for NB69 neuroblastoma cells. Urotensin II receptor mRNA was expressed in all 7 tumor cell lines. A significant amount of urotensin II-like immunoreactivity was detected only in the culture medium of SW-13 adrenocortical carcinoma cells by radioimmunoassay. Sephadex G-50 column chromatography showed that the urotensin II-like immunoreactivity in the culture medium extract was eluted earlier than synthetic human urotensin II, suggesting that SW-13 cells secreted higher molecular weight materials, perhaps partially processed forms of the urotensin II precursor. Reverse phase high-performance liquid chromatography (HPLC) showed three immunoreactive peaks, one of which was eluted in the position of urotensin II. The present study has shown for the first time expression of urotensin II and urotensin II receptor mRNAs in various tumor cell lines and the secretion of urotensin II-like immunoreactivity by SW-13 adrenocortical carcinoma cells.