What Can We Learn From Germ Line Cells?
Ouroboros looks at that little piece of immortality that resides in all of us: "The germ line (the cell lineage from which reproductive cells are derived) is replicatively immortal - distinct from the soma, where most cells capable of division have a strictly limited replicative capacity, if they're not entirely postmitotic. Why? ... Understanding the proliferative perseverance of the germ line is particularly important when one considers the way in which germ cells violate one of the time-honored justifications for a replicatively limited soma, namely, that an unlimited replicative capacity would place a cell at risk for initiating cancer ... Certainly, germ-line derived tumors are not unheard of, but they are rare, even though everyone's got germ cells - so these lineages serve as an example of replicative immortality that does not confer an unusual risk of carcinogenesis." Does the key to engineering cancer-free human biochemistry lie somewhere in our germ cells? We will probably know - in detail - the answer to that question within the next twenty years.
Link: http://ouroboros.wordpress.com/2006/11/17/germ-line-vs-somatic-immortality/