Establishment and characterization of a new cell line from a hereditary renal rat tumor

A new cloned tissue culture cell line, HRRT, has been established from a hereditary renal rat tumor. Electron microscopic studies indicate that the cells are fibroblasts. The cell line has been maintained in monolayer cultures for more than 3 yr and multiplies with a population doubling time of 21 h. The HRRT cells were found to have a plating efficiency of 50% and were not able to grow at low serum concentrations; they did not multiply in suspension culture and were unable to form colonies in soft agar or to proliferate in the aggregate form. The HRRT cells did not form tumors in nude mice. The new cell line was adapted to grow in serum-free medium by decreasing the serum concentration gradually over a period of several months and by addition of sodium pyruvate, insulin, alanine, serine, ribose, thymidine, and uridine to the medium. In serum-free medium HRRT cells multiplied with a population doubling time of 42 h and were not able to form colonies in soft agar.