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Updated: Jun 14, 2026
Isolation and Immortalization of Patient-derived Cell Lines from Muscle Biopsy for Disease Modeling
Published on: January 18, 2015
How to become immortal: let MEFs count the ways
Adam Odell1, Jon Askham, Catherine Whibley
1Faculty of Medicine and Health, University of Leeds, LIGHT Laboratories, Leeds, UK.
Abstract:
Understanding the molecular mechanisms and biological consequences of genetic changes occurring during bypass of cellular senescence spans a broad area of medical research from the cancer field to regenerative medicine. Senescence escape and immortalisation have been intensively studied in murine embryonic fibroblasts as a model system, and are known to occur when the p53/ARF tumour suppressor pathway is disrupted. We showed recently that murine fibroblasts with a humanised p53 gene (Hupki cells, from a human p53 knock-in mouse model) first senesce, and then become immortalised in the same way as their homologues with normal murine p53. In both cell types, immortalised cultures frequently sustain either a p53 gene mutation matching a human tumour mutation and resulting in loss of p53 transcriptional transactivation, or a biallelic deletion at the p19/ARF locus. Whilst these genetic events were not unexpected, we were surprised to find that a significant proportion of immortalised cell cultures apparently had neither a p53 mutation nor loss of p19/ARF. Here we consider various routes to p53/ARF disruption in senescence bypass, and dysfunction of other tumour suppressor networks that may contribute to release from tenacious cell cycle arrest in senescent cultures.
Insights
Cellular senescence bypass involves genetic changes, often disrupting the p53/ARF tumor suppressor pathway. Unexpectedly, some immortalized cells lacked typical p53 mutations or ARF deletions, suggesting alternative mechanisms for senescence escape.
Area of Science:
- Molecular biology
- Cancer research
- Regenerative medicine
Background:
- Cellular senescence is a state of irreversible cell cycle arrest.
- Senescence escape and immortalization are critical in cancer development and regenerative medicine.
- The p53/ARF tumor suppressor pathway is a key regulator of senescence.
Purpose of the Study:
- To investigate the genetic mechanisms underlying senescence bypass.
- To explore alternative pathways for disrupting the p53/ARF pathway during immortalization.
- To understand the role of other tumor suppressor networks in releasing senescent cells.
Main Methods:
- Utilized a humanized p53 knock-in mouse model (Hupki cells).
- Compared genetic alterations in immortalized murine embryonic fibroblasts with normal and humanized p53.
- Analyzed p53 gene mutations and p19/ARF locus deletions.
Main Results:
- Both normal and Hupki cells senesce and can become immortalized.
- Immortalized cells frequently acquired p53 mutations or p19/ARF deletions.
- A significant proportion of immortalized cells lacked these expected genetic alterations.
Conclusions:
- Senescence bypass involves genetic events, primarily targeting the p53/ARF pathway.
- The study identified unexpected genetic routes to immortalization, suggesting broader mechanisms of tumor suppressor network dysfunction.
- Further research is needed to elucidate these alternative pathways for senescence escape.
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