Science of Aging  

Norman E. Sharpless Finds That Expression Of The Ink4a/Arf Locus Is A Biomarker Of Aging

Who:Norman E. Sharpless, Janakiraman Krishnamurthy, Chad Torrice, Matthew R. Ramsey, Grigoriy I. Kovalev, Khalid Al-Regaiey, Lishan Su
When:November 01, 2004
Methods: Using PCR assays on the expression of cyclin-dependent kinase inhibitor family members to find variations in expression of the gene p16INK4a
Institution: UNC Chapel Hill
Where: Chapel Hill, North Carolina, U.S.A
Funding: Sidney Kimmel Foundation for Cancer Research

Sharpless et al. have found that expression of the Ink4a/ARF locus is increased in aging cells. The Ink4a/ARF locus is also associated with cancer suppression via the molecules, p16INK4a and ARF.

They chose to look at p16INK4a and ARF because they appear to play a key role in stem cell lifespan in vivo.

Looking at cell regulation, Sharpless et al. used PCR assays of cyclin-dependent kinase inhibitor family members of both young and old cells. They found a 3 fold increase in p16INK4a expression in old cells, and a 3.5 fold increase of ARF expression in old cells.


  1. Krishnamurthy J, Torrice C, Ramsey MR, Kovalev GI, Al-Regaiey K, Su L, Sharpless NE. Ink4a/Arf expression is a biomarker of aging. J Clin Invest. 2004 Nov;114(9):1299-307.