Why are some cell lines immortalized with hTERT alone and others with hTERT and HPV E6/E7?
Fully understanding how to successfully immortalize some cell types is an active area of research. Transfection with hTERT alone appears to be fully capable of immortalizing many cell types. Some cell types require additional cellular intervention to become fully immortalized. This process often involves suppressing the activities of the p16/INK4a, pRB, and p53 cell cycle checkpoints. This is often accomplished by transfecting cells with hTERT and a viral transformation agent, such as HPV E6/E7 or SV40.
