You have two choices as a cell and as a human (well, you have billions of choices, but for the purposes of this discussion let’s limit it to two) – you can either make a decision and become something, or keep your options open and don’t become anything.
Stem cells are the latter. They don’t do much except make more of themselves -they’re just one little bundle of potential!
An embryonic stem cell has the potential to become any cell in the body. From when you are seven days old or so, a mere 150 cell mass, your cells begin to lose that potential, and they start differentiating down into adult stem cells. These are like partly differentiated cells… like students that haven’t picked their major yet, for instance haemopoietic stem cells live in your bone marrow and create all the blood cells in your body, red and white. Basically I see differentiation as a process of gaining a function, but losing the possibility of having other functions – like specialising in a subject or buying a house, or getting married.
This is described briefly in MY FIRST VIDEO!
I may have gotten slightly distracted by lip syncing into the inbuilt mac webcam while making this (admittedly very average) video. Promise the quality of these videos will improve dramatically so bear with me, bear with me, bear with me, BE WITH ME TONIGHT! Dumdumdumdaadaa I know that it isn’t right… Dumdumdumdaadaa be with me tonight…
At least I didn’t upload the lip syncing to youtube. Could be worse.
So, why the fuss on stem cells? They’ve been in the media spotlight for a few years as the one-day wonderdrug. People hope that we can take stem cells from our own body (harvested from when you are an embryo, or taken from your nose or something and converted back to embryonic state) and turn them into any part of the body you need. Need a new liver? We’ll grow one for you! Insulin-producing cells for diabetics? No problem! New brain cells for Alzheimer’s? You get the idea…
One of the biggest bonuses is that it uses your own DNA, so the chance of rejection is low, and if it’s grown in the lab it’s probably free of disease and stuff. Some of the negatives are the could-become-cancerous thing, and the aren’t-embryos-alive-and-shouldn’t-we-not-kill them thing. My biggest concern is the government dressing up like aliens and taking eggs from abducted women like Scully, but that’s me. Oh, and stuff like in the movie The Island.
Say what you might about the ethical greyness, stem cell therapies have a lot of potential (lol, sry), but are still a ways down the track. It’s pretty tricky to get all the messages to the cell in culture in the right order, concentration, and combination so that you end up with a proper liver cell and not just a lump of tumour. Still, it is possible… I’ve seen some stem cell derived heart cells in teh lab, very cool stuff, they all spontaneously contract together like a beating heart, quite a sight to see.