Cell Death Nets 2002 Nobel Prize in Medicine

An anonymous reader writes "The recent press release at the Nobel website details the first of the 2002 Nobel Prizes. This year the Medicine prize goes to Sydney Brenner, H. Robert Horvitz, and John E. Sulston for their discovery of programmed cell death (also called apoptosis). Their seminal work in the model organism C. elegans established the foundation of cell suicide as a normal physiologic process. The implications are wide ranging including understanding organ development and cancer."

Comments

Death?

[joyoflinux]

Probably has some implications in to why we die...could understanding why cells die when they do help create ways to make us live longer?

A primer on Apoptosis (Programmed Cell Death)

[madcoder47]

<p>Because it is an interesting and often misunderstood subject, here is a small
primer on the topic of apoptosis (Programmed Cell Death). <br>
FYI I work in an immuno lab which uses apoptosis as a main treatment for transplant
tolerance.</p>
<p><strong><em>Deat h by suicide</em></strong></p>
<p>Cells that are induced to commit suicide: </p>
<ul>
<li>shrink
<li>have their mitochondria break down with the release of cytochrome c
<li>develop bubble-like blebs on their surface
<li>have the chromatin (DNA and protein) in their nucleus degraded
<li>break into small, membrane-wrapped, fragments
<li>The phospholipid phosphatidylserine, which is normally hidden within the
plasma membrane is exposed on the surface.
<li>This is bound by receptors on phagocytic cells like and dendritic cells
which then engulf the cell fragments.
<li>The phagocytic cells secrete cytokines that <b>inhibit inflammation</b>.
</ul>
<p>The pattern of events in death by suicide is so orderly that the process is
often called <b>programmed cell death</b> or <b>PCD</b>. The cellular machinery
of programmed cell death turns out to be as intrinsic to the cell as, say, mitosis.
</p>
<p>Why should a cell commit suicide?</p>
<p>There are two different reasons. </p>
<p><strong>1. Programmed cell death is as needed for proper development as mitosis
is.</strong></p>
<blockquote>
<p><em>Examples: </em></p>
<ul>
<li>The resorption of the tadpole tail at the time of its metamorphosis into
a frog occurs by apoptosis. </li>
<li>The formation of the fingers and toes of the fetus requires the removal,
by apoptosis, of the tissue between them. </li>
<li>The sloughing off of the inner lining of the uterus (the endometrium)
at the start of menstruation occurs by apoptosis. </li>
<li>The formation of the proper connections (synapses) between neurons in
the brain requires that surplus cells be eliminated by apoptosis</li>
</ul>
</blockquote>
<p><strong>2. Programmed cell death is needed to destroy cells that represent
a threat to the integrity of the organism.</strong></p>
<blockquote&gt ;
<p><em>Examples:</em> </p>
<dl>
<dl>
<dt><b>Cells infected with viruses</b> </dt>
<dd>One of the methods by which <b>cytotoxic T lymphocytes</b> (CTLs) kill
virus-infected cells is by inducing apoptosis. (And some viruses mount
countermeasures to thwart it.) </dd>
<dt><b>Cells with DNA damage</b></dt>
<dd>Damage to its genome can cause a cell
<ul>
<li>to disrupt proper embryonic development leading to birth defects
</li>
<li>to become cancerous.</li>
</ul>
<p>Cells respond to DNA damage by increasing their production of p53.
p53 is a potent causer of apoptosis. Is it any wonder that mutations
in the p53 gene, producing a defective protein, are so often found in
cancer cells (that represent a lethal threat to the organism if permitted
to live)? </p>
</dd>
<dt><b>Cancer cells</b></dt>
<dd>Radiation and chemicals used in cancer therapy induce apoptosis in some
types of cancer cells.</dd>
</dl>
</dl>
</blockquote>