Some recent work on cell senescence demonstrates one of my recurring points: we have reached the stage at which all new knowledge of cellular biochemistry and genetics found in the course of a single field of research has wider applications. We are seeing the ties between aging and cancer, for example, and the ways in which different conditions related to the same biochemical processes.
Earlier studies have demonstrated that as cells reach senescence, an alteration in chromatic structure called senescence-associated heterochromatin foci (SAHF) silences the genes that trigger the cells growth. This discovery reveals the process of SAHF formation. SAHF are domains of tightly packed chromatin that repress activity of the genes that normally trigger cell proliferation. The Fox researchers have identified at least three proteins in the cell that contribute to the formation of SAHF. These proteins are called ASF1a, HIRA, and promyelocytic leukemia (PML). Scientists have known for a while that PML suppresses the formation of this type of leukemia, but do not know why.
This research suggests the possibility that PML arises because the PML protein is not able to do its job in forming SAHF. If this is true, this study might help in the design of therapeutic drugs to treat cancer patients and even lessen some aspects of aging. Additional study in this field will define the molecular details by which HIRA, PML, and ASF1 and formation of SAHF may also be a factor in other human cancers.
The incidental benefits of fields like stem cell research and modern cancer research - focusing as they do on cellular biochemistry - are large. This new knowledge will serve as a basis for the targeted healthy life extension research of the future.