Establishment and characterization of rat pancreatic beta cell lines transformed by simian virus 40.

Rat pancreatic beta cells were transformed by simian virus 40 (SV40). The established beta cell lines expressed tumor antigen specific to SV40 and retained the ability to produce immunoreactive insulin (IRI) even at a high passage level. One of 12 transformed beta cell lines, SV-PB1205, was further investigated in vitro and in vivo. Firstly, effects of drugs on replication of the pancreatic beta cells were examined in in vitro experiments. Various drugs increased the uptake of 3H-thymidine into the cells. Those included D-glucose, tetragastrin and secretin. However, such effect was not observed for glucagon and growth hormone. Secondly, the SV40-transformed pancreatic beta cells were transplanted into diabetic rats. This produced such improvement of plasma glucose level at least for 2 weeks. The Significance of those experiments was discussed.