[I pin this post to the top for a little while in February most years now; some of it (not the important stuff) is obviously out of date!]
OK I’ve mostly avoided mentioning anything about today’s date but a few people scuppered the plan as expected. Oh well. Happy greetings-card-marketing day 😉
I’ll stop being miserable now, let’s talk science!
People ask me what I do quite a lot. I work* in a Cancer Research centre in a group called the ‘Cell Adhesion and Angiogenesis lab’, which is a mouthful. *Ed: used to work, pre-2013
Cells, for anyone who is unaware, are the building blocks of the body. One single bacterium is a cell; they’re unicellular organisms. We mammals are multicellular; our bodies are made up of lots of individual cells. Those cells obviously have to stick to each other and to the non-cell elements of the body (bones and all the other inter-cellular stuff) or we’d fall apart!
So that’s what cell adhesion is – how cells stick to and interact with each other and their environment.
Angiogenesis is the growth of new blood vessels from pre-existing ones.
All the body’s cells need oxygen and food to stay alive. They also need to get rid of waste products like carbon dioxide. The blood carries oxygen (via haemoglobin in the red blood cells) and nutrients, so the blood itself needs to be delivered to all the body’s tissues, pumped around by the heart.
All our blood vessels are lined with a particular cell type, called endothelial cells. These guys are the main focus of our lab work, but not the only cell type involved in angiogenesis – indeed, we’re not sure what some of the cell types are exactly, or how they all work together – but that’s what research is for!
When new blood vessels are needed (e.g. to heal a wound, during the menstrual cycle, in development etc.), endothelial cells ‘wake up’ from their usually sleepy state in response to various cues from the environment – not all of which we understand – and grow and move to form new vessels.
This process is normal and necessary, but tightly regulated – switching off the response is just as important as switching it on – but it can go wrong, as the existence of more than 70 angiogenesis-related diseases shows.
The case we are particularly interested in is of course cancer – tumour cells are growing out of control so they want as much oxygen and nutrients as they can get. Solid tumours (i.e. all cancers except those of the blood) entice blood vessels to grow towards and into them, waking up nearby endothelial cells.
We want to understand how that process works; the field is relatively young, having really got going in the 80s when a major protein was discovered that causes endothelial cells to grow; vascular endothelial growth factor (VEGF), which again is another research focus in our group.
As I said, we don’t even know all the cell types involved, how they interact, what they respond to – all things we need to learn about if we’re going to make decent cancer drugs.
This is why we can’t just use computers as a lot of anti-vivisectionists like to suggest; you can’t put into a computer program what you do not know about.
Anyway, back to the researching; we do an experiment quite a lot, called the aortic ring assay. The aorta is the major blood vessel that leaves the heart. We put little rings of aorta into collagen (one of the components of the ‘stuff’ outside cells I mentioned) and see how many tiny vessels sprout from them. I’m writing a paper about it at the moment actually, not that we invented the technique or anything.
This can give us information about how endothelial cells respond to various treatments and how angiogenesis is affected; whether we’re altering some genes (making them more or less active than normal) or adding some drugs to the rings’ food.
We can look at different cell types and how the sprouts look; long/short, few/many, straight/tortured, thick/thin – you get the idea.
The picture below is from one of my experiments late last year. The aortic ring (bright central bit) here is on its side, with the middle of the vessel (the lumen, through which blood flows) pointing left/right relative to the screen so you’re looking at the outer wall. It’s about 0.5 millimetres across.
The colours show Endothelial cells, pericytes and fibroblasts and DNA in the nuclei – I can go into how one gets the colours if anyone’s interested, but otherwise you can just enjoy my serendipitous Valentine’s-themed image; I grew a heart from a bit of heart. Sorta.