What are immortalized cell lines?

Answer 1

A biologically immortal cell (or, more likely, cell lineage) can continue to divide indefinitely, and will not fail due to DNA failures. Each time DNA divides, some of the ends are cut off, and after some time, something will be cut off at one end that is very important, and the cell may stop working correctly or even die. An immortal cell would have to pad the ends of its DNA to avoid this kind of damage. Cancer cells already do this, as well as stem cells and many others. It is important to note that while the cell lineage could continue forever, disease or damage could still kill the organism.

Answer 2

a population of cells from a multicellular organism which would normally not proliferate indefinitely but, due to mutation, have evaded normalcellular senescence and instead can keep undergoing division.

Primary cells normally have a limited life span and after having undergone a certain number of population doublings stop dividing, this is known as senescence. Re-establishing fresh cultures from explanted tissue is a tedious process. However, using immortalized cells can solve this problem. Immortalized cells have extended replicative capacity and offer the possibility of an inexhaustible supply of cells throughout your research project.

There are several methods for generating immortalized cell lines by Creative Bioarray. One method is introduction of a viral gene that partially deregulates the cell cycle, such as EBV, SV40 T antigens and HPV-16 E6/7 gene. Artificial expression of key proteins required for immortality is another approach to induce immortalization, for example telomerase which prevents degradation of chromosome ends during DNA replication in eukaryotes. Another method is inactivation of tumor suppression genes, such as p53, Rb and others.