PT  - JOURNAL ARTICLE
AU  - Jennifer R. Peters-Hall
AU  - Jaewon Min
AU  - Enzo Tedone
AU  - Sei Sho
AU  - Silvia Siteni
AU  - Ilgen Mender
AU  - Jerry W. Shay
TI  - Human Lung Epithelial Cells Divide >200 Population Doublings without Engaging a Telomere Maintenance Mechanism
AID  - 10.1101/474270
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 474270
4099  - http://biorxiv.org/content/early/2018/12/01/474270.short
4100  - http://biorxiv.org/content/early/2018/12/01/474270.full
AB  - The “Hayflick limit” is a “mitotic clock” and primary cells have a finite lifespan that correlates with telomere length. However, introduction of the telomerase catalytic protein component (TERT) is insufficient to immortalize most, but not all, human cell types under typical cell culture conditions. Originally, telomerase activity was only detected in cancer cells but is now recognized as being detectable in transit amplifying cells in tissues undergoing regeneration or in extreme conditions of wound repair. Here we report that in vitro low stress culture conditions allow normal human lung basal epithelial cells to grow for over 200 population doublings without engaging any telomere maintenance mechanism. This suggests that most reported instances of telomere-based replicative senescence are due to cell culture stress-induced premature senescence.One Sentence Summary Human lung cells growing in reduced stress conditions can divide well beyond the Hayflick limit.Author ContributionsConception and design: JRP, JM, ET, JWS; Performing experiments: JRP, JM, ET, SS, SS, IM; Analysis and interpretation: JRP, JM, ET, SS, SS, IM, JWS; Drafting the manuscript for intellectual content: JRP, JWS