Juxtaglomerular cell tumor cell line producing active renin and its precursors

We have established tumor cell lines from a rare juxtaglomerular cell tumor (JGCT) of the kidney. The original tumor contained both neoplastic cells and a tubular component. The tumor cell line (JX-G) maintained a capacity for renin production after the 20th passage. Cells at the fourth and 16th passage strongly reacted immunocytochemically with an antihuman renin antibody. Western blot analysis at the 9th passage revealed a positive reaction for renin at M(r) 45,000 and M(r) 62,000 which corresponded to renin precursors. However, the total amount of active renin secreted into the culture medium was high in the primary culture, but undetectable after the 4th passage. These findings indicate that the JGCT cell lines produced both active and inactive renin and the primary cultured JGCT cells secreted active renin, but that the secretion of renin had diminished after several passages. Additional stimuli thus appear necessary for maturation of renin and its subsequent secretion. These findings and the presence of a tubular component in the original tumor suggest that some signal transduction system is maintained in JGCTs. The physiological relationship of JGCT to the juxtaglomerular apparatus (JGA) and possible applications of the new cell lines are also discussed.