Oncogene-immortalized Cell Lines

Oncogene-immortalized Cell Lines are generated by introducing specific oncogenes or viral genes that override cell cycle checkpoints and extend proliferative lifespan, often leading to full immortalization and sometimes transformation. E6/E7 immortalization is a common method using human papillomavirus (HPV) E6 and E7 proteins, which degrade p53 and inactivate Rb respectively. HPV-16 E6/E7 expression are existed in cervical cancer models and widely used for immortalizing primary human cells such as keratinocytes, fibroblasts, and epithelial cells. C-myc immortalized lines overexpress the MYC oncogene, which drives proliferation and metabolic reprogramming. SV40 large T antigen immortalized cells (SV40 TAg) inactivate both p53 and Rb, leading to extended lifespan but often not full transformation; HEK293 cells contain SV40 TAg. hTERT/oncogene combinations (e.g., hTERT + SV40, hTERT + RAS) produce robust immortalization and are used for creating long-term models of human cells. Cyclin D1 immortalized cells overexpress cyclin D1, driving G1/S transition; they are used for breast cancer and mantle cell lymphoma models. CDK4 immortalized (cyclin-dependent kinase 4) similarly drives cell cycle progression. E1A immortalized cells express adenovirus E1A, which binds Rb and disrupts its function; they are used for transformation studies and for creating immortalized human cell lines.