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 v arious human tumor cell lines by reverse transcriptase polymerase chain rea ction (PCR) method. Secretion of urotensin II by these tumor cells was stud ied by radioimmunoassay. The tumor cell lines studied were T98G glioblastom a cells, IMR-32 neuroblastoma cells, NB69 neuroblastoma cells, BeWo chorioc arcinoma cells, SW-13 adrenocortical carcinoma cells, DLD-1 colorectal aden ocarcinoma cells and HeLa cervical cancer cells. Urotensin II mRNA was expr essed in 6 tumor cell lines except for NB69 neuroblastoma cells. Urotensin II receptor mRNA was expressed in all 7 tumor cell lines. A significant amo unt of urotensin II-like immunoreactivity was detected only in the culture medium of SW-13 adrenocortical carcinoma cells by radioimmunoassay. Sephade x G-50 column chromatography showed that the urotensin II-like immunoreacti vity 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 i mmunoreactive peaks, one of which was eluted in the position of urotensin I I. The present study has shown for the first time expression of urotensin I I and urotensin II receptor mRNAs in various tumor cell lines and the secre tion of urotensin II-like immunoreactivity by SW-13 adrenocortical carcinom a cells. (C) 2001 Elsevier Science Inc. All rights reserved.