The capacity of avian retrovirus-induced sarcomas to expand by infectious virus production

Loss of transformed phenotype upon senescence of Rous sarcoma virus-infected chicken neuroretinal cells

“…2, there was a significant decrease in the size of soft-agar colonies after 2 weeks of growth, between passages 8 ( Fig. 2A) and 12 at passage 12. This would suggest a true decrease of anchorage independence, as opposed to solely a loss of cell viability.…”

“…Similarly, in the present study, chicken neuroretinal cells, transformed and maintained in vitro, display diminished viral effects with cell passage. In vivo, recruitment of new cells (12), as well as the continuing division of previously infected cells (36), has been shown to be important for growing tumors. Likewise, in vitro, the senescence phenomenon has led some investigators to continually replenish RSV-transformed chicken cell cultures with fresh, uninfected cells to maintain the infected cell populations (26).…”