Telomerase reactivation and immortalization are critical for human carcinoma progression. However, little is known about the mechanisms controlling this crucial step, due in part to the paucity of experimentally tractable model systems that can examine human epithelial cell immortalization as it might occur in vivo. We achieved efficient non-clonal immortalization of normal human mammary epithe...

The authors have established an in vitro model system which demon strates the progression of the transformed phenotypes of human cervical epithelial cells transfected with human papillomavirus (HPV) type 16 and 18 DNAs. Both viral DNAs exhibit immortalizing potential; however, only HPV 18-immortalized cell lines progress to exhibit anchorage-indepen dent growth and, in a limited number of cases...

The acquisition of immortalization is an early and carefully documented event in mouse mammary tumorigenesis. Activation of telomerase activity is one hypothesis to explain the acquisition of immortalization. We examined the activity of telomerase in well-defined immortalized, non-tumor cell populations of mouse mammary tissue in vivo. The results indicated that normal virgin and mid-pregnant m...

The authors have established an in vitro model system which demonstrates the progression of the transformed phenotypes of human cervical epithelial cells transfected with human papillomavirus (HPV) type 16 and 18 DNAs. Both viral DNAs exhibit immortalizing potential; however, only HPV 18-immortalized cell lines progress to exhibit anchorage-independent growth and, in a limited number of cases, ...

Scaffold attachment factor B1 (SAFB1) is a multifunctional protein, which has previously been implicated in breast cancer. Here, we show that genetic deletion of SAFB1 in mouse embryonic fibroblasts (MEF) leads to spontaneous immortalization and altered expression of two proteins involved in immortalization and escape from senescence: low levels of p19 and high levels of TBX2. Inactivation of T...

Recent analyses have identified a number of binding partners for E6, including E6AP, ERC55, paxillin, hDlg, p300, interferon regulatory factor 3, hMCM7, Bak, and E6TP1. Notably, association with E6 targets p53, E6TP1, myc, hMCM7, and Bak for degradation. However, the relative importance of the various E6 targets in cellular transformation remains unclear. E6 alone can dominantly immortalize nor...

Nasopharyngeal carcinoma (NPC) is common among southern Chinese including the ethnic Cantonese population living in Hong Kong. Epstein-Barr virus (EBV) infection is detected in all undifferentiated type of NPC in this endemic region. Establishment of stable and latent EBV infection in premalignant nasopharyngeal epithelial cells is an early event in NPC development and may contribute to its pat...

carcinogenesis is a multistep process characterized by the gradual accumulation of genetic changes that ultimately lead to cancer. these genetic mutations can impart limitless replicative potential to the cancer cells making them immortal. telomeres are repeat nucleotide sequence ttaggg that are present at the end of chromosomes. its functions are to protect the chromosomal ends and to ensure t...

In modern science, immortalized cells are not only a convenient tool in fundamental research, but they also increasingly used practical medicine. This happens due to their advantages compared the primary cells, such as possibility produce larger amounts of and use them for longer periods time, convenience genetic modification, absence donor-to-donor variability when comparing results different ...

The finite proliferative potential of normal human fibroblasts can be overcome, a process commonly called immortalization, by the introduction of the catalytic subunit of human telomerase. In contrast to malignant transformation, the pattern of gene expression remains largely unmodified in telomerase-induced immortalization. Here we show evidence that suggests that the maintenance of a "young" ...