Have there been studies done to test Immortality of cancer cells in culture? This website on cultured cancer cells () says cancer cells _may be immortal_. I am wondering if there has been any research done to find if cancer cells are really immortal. 1. How old is the still maintained living oldest culture of cancer cells? 2. Has there been any research done on replicative senescence of Cancer Cells invitro? Edit 1: If there is some data relating to the number of replications the cells have undergone, it will be very useful

The HeLa cell line is undoubtedly the most used and investigated **human** immortal tumor cell line. Extracted from a cervical tumor from Henrietta Lacks in 1951 at Johns Hopkins hospital, Baltimore, MD these cells proved immortal and are still used in many, many labs worldwide today. It is the oldest human cell line in use and, therefore, the **oldest human tumor cell line** (Callaway, 2013).

In terms of **senescence** of immortal cells; HeLa cells are immortal, and hence do not grow old as such. However, they are subject to mutations and the **genetic profile of HeLa cells does change over time**. Hence, although they may not be growing old, they do age in the sense that mutations are accumulating in continuous cell lines.

**References**
Callaway, _Nature_ (2013); **500** : 132-3