Hayflick's hypothesis: an approach to in vivo testing

Area of Science:

• Gerontology
• Cell Biology
• Biogerontology

Background:

• The hypothesis of finite cellular life suggests biological limitations on cell proliferation.
• Somatic cell production, even if limited, has a vast potential for regeneration.
• This vast potential implies that natural lifespans may not reach the reproductive limit of cells.

Purpose of the Study:

• To review experimental evidence for the finite cellular life hypothesis.
• To propose a method for experimentally testing the finite cellular life hypothesis.

Main Methods:

• Review of existing experimental evidence.
• Proposal of a novel experimental approach: deliberate exhaustion of stem-cell reserve.
• Description of iron-55 cytocide as a potential experimental system.

Main Results:

• Experimental evidence does not strongly support a finite cellular life limit being reached within a normal lifespan.
• The potential for cellular regeneration is vast, suggesting resilience against reaching reproductive limits.
• A method to experimentally test the hypothesis is proposed.

Conclusions:

• The actual limit of reproductive cell life is unlikely to be reached in a normal lifespan.
• Deliberate exhaustion of stem-cell reserve is a viable strategy to test the finite cellular life hypothesis.
• Iron-55 cytocide offers a potential experimental system for this investigation.