Tumors Induced in Hamsters by Injection of Rhesus Monkey Kidney Cell Extracts

Summary

Injection of newborn hamsters with extracts of certain lots of rhesus monkey kidney cell cultures has been followed some months later by occurrence of neoplasms at site of injection in 109 of 154 hamsters. Three of the neoplasms were transplanted to other hamsters and the recipient hamsters developed tumors in 13 to 48 days. Transplants from the second tumor were passed from hamster to hamster 5 times and tumors developed in all surviving animals in 6 to 24 days. Tumors could not be induced in newborn hamsters by inoculation of extracts of the hamster tumors. No changes indicative of a virus were observed when extracts of a tumor or a tumor mince were incubated with primary mouse embryo, primary vervet monkey kidney cells, or a continuous line of rhesus monkey kidney cell cultures. The tumors appeared to be somewhat different from those induced by the SE polyoma virus.