Cellular senescence or stemness: hypoxia flips the coin
Daniel Otero-Albiol1,2, Amancio Carnero3,4
1Instituto de Biomedicina de Sevilla, IBIS, Hospital Universitario Virgen del Rocío, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Avda. Manuel Siurot s/n, 41013, Seville, Spain.
Journal of Experimental & Clinical Cancer Research : CR
|July 30, 2021
Summary
Hypoxia, or low oxygen, may help cells bypass senescence, promoting tumor growth and aggressiveness by enabling stemness properties. This challenges the view of senescence solely as a tumor suppressor mechanism.
Area of Science:
- Cellular and Molecular Biology
- Cancer Research
- Physiology
Background:
- Cellular senescence is a state of irreversible proliferative arrest, often viewed as a tumor suppressive mechanism.
- Hypoxia (low oxygen) is a common condition in tissues and has been observed to increase the lifespan of primary cells.
- Hypoxia is known to promote self-renewal and pluripotency in various stem cell types, including cancer stem cells.
Purpose of the Study:
- To investigate whether hypoxia modulates cellular senescence and its antiproliferative capacity.
- To explore the role of hypoxia in facilitating senescence bypass during malignant transformation.
- To understand how hypoxia contributes to the acquisition of stemness properties in cancer development.
Main Methods:
- Review and discussion of existing literature on cellular senescence and hypoxia.
- Analysis of studies investigating the effects of low oxygen on cell lifespan and stem cell properties.
- Synthesis of evidence linking hypoxia, senescence evasion, and cancer aggressiveness.
Main Results:
- Hypoxia appears to increase the lifespan of mammalian primary cells, suggesting a modulation of senescence.
- Hypoxia promotes self-renewal and pluripotency in embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and cancer stem cells (CSCs).
- Hypoxia facilitates bypassing senescence during malignant transformation and the acquisition of stemness.
Conclusions:
- Hypoxia plays a significant role in promoting tumor development and increasing cancer aggressiveness.
- The ability of hypoxia to facilitate senescence bypass and promote stemness properties is a key mechanism in cancer.
- Cellular senescence may not solely act as a tumor suppressor, as its function can be altered by hypoxic conditions.
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