metastasis

from this month's scientific american:

"The complexity of this system [the relationship of any single gene with the myriad networks in which it participates] in normal cells is evident in what we already know about cancer -- that it results from the stepwise loss of such cellular self-control, which becomes more and more complete as the disease progresses."
-- Renato Dulbecco

The Hallmarks of Cancer
The six abnormal capabilities listed below together give tumors their lethal power to overrun their native tissue and spread through the body.
Self-sufficiency in growth signalling
Cancer cells amplify external growth cues or generate their own.
Insensitivity to antigrowth signals
Cancer cells become deaf to quiescence cues from surrounding tissue.
Evasion of cell suicide
Mechanisms that should trigger or carry out a self-destruct program in damaged cells are disabled or overridden.
Limitless replicative potential
Cancer cells evade intrinsic limits on the number of times a normal cell can divide.
Sustained blood vessel growth
Tumors emit signals promoting the development of new blood vessels to deliver oxygen and nutrients.
Invasiveness and motility
Cancer cells defy multiple signals and forces that hold a cell in place and prevent it from traveling to - and thriving in - other tissues.

and then, from atwood, morning in the burned house, circa 1995 (courtesy j.)

Cell
Now look objectively. You have to
admit the cancer cell is beautiful.
If it were a flower, you'd say, How pretty,
with its mauve centre and pink petals

or if a cover for a pulpy thirties
sci-fi magazine, How striking;
as an alien, a success,
all purple eye and jelly tentacles
and spines, or are they gills,
creeping around on granular Martian
dirt red as the inside of the body,

while its tender walls
expand and burst, its spores
scatter elsewhere, take root, like money,
drifting like a fiction or
miasma in and out of people's
brains, digging themselves
industriously in. The lab technician

says, It has forgotten
how to die. But why remember? All it wants is more
amnesia. More life, and more abundantly. To take
more. To eat more. To replicate itself. To keep on
doing these things forever. Such desires
are not unknown. Look in the mirror.

martin sexton - hallelujah