utenzi

David Cheresh, a well known researcher from UCSD, gave a lecture here at UNC today. In a somewhat unusual departure from my normal habit, I actually attended and took notes. If you're curious, the title was "A Role for VEFG as a Negative Regulator of Pericyte Function and Blood Vessel Maturation." Both VEGF and PDGF are angiogenesis stimulators, and as you'd expect, both increase the growth rate of cancer tumors. What you might not expect is that if VEGF and PDGF are administered together, in tumors with receptors for both peptides, the blood vessels in the tumors regress. That is, the growth factors separately improve neovascularization but together, where you'd expect some synergy, instead they suppress neovascularization. Weird. What I found interesting is the clinical application of this research. You see, tumors tend to support their rapid growth by secreting a butt load of VEGF, which increases angiogenesis; however it does so in a pell-mell fashion which ...

Here's one of the things that was keeping me busy at work on Tuesday. You probably all recognize this. It's a microscope! I spend a lot of time around microscopes. In this case we're quantifying the formation of tubes in response to some peptides we added to the cells after first allowing them to grow for 3 days. In the picture on the left, you can see the 96 well plate that we use to grow the cells in. While we use a lot of different type of cells, in this case we're using a murine (mouse) model. Since the bottom of the wells in a 96 well plate are so small, it's hard to get a good image of the cells growing there. That's why we wander across campus and go to a core facility which has as its sole purpose to provide imaging assistance to troubled researchers like me. This is a wider view of the microscope setup that I was using. It's just one of over a dozen workstations. There's a number of different types here ranging from simple dissection scopes to t...

Or maybe I should title this post eggs and software. When I do a CAM (Chorioallantoic Membrane) assay, which is an in vivo angiogenesis model, getting the results is a 3-step process. First of all, of course you have to do the experiment, which isn't trivial since there's so many damn things that can go wrong. Some eggs aren't fertilized, lots of eggs develop problems when you break them, and there's some eggs that, for no apparent reason, don't develop properly after being added to a petri dish. Yet, eventually we end up with eggs that look like the picture above. Around 30% will develop all the way and we have 3 - 5 discs per egg which adds up to a faily significant number--statistically speaking. So step two is taking the picture. But getting the picture up on top is just the first step in the analysis. Each disc (these are filters that have drug added to them--or saline in the case of controls--so we can see what affect there is on angiogenesis) gets photographe...

The current project that I'm working on is a chicken based model for angiogenesis called CAM (Chorioallantoic Membrane). It's pretty simple. You buy fertilized eggs, place them in an incubator for a few days, then crack the eggs and add the contents to petri dishes. At this point they've been warm for 3 days and you can start to see some chick development but it's only a wee small thing. Several days later we add drug to some of the petri dishes--right on the yolk--and don't add the drug to the rest so as to have controls. Several days later you compare the controls to the drug added yolks and use that information to determine if the drug affects angiogenesis. It's a great system because the affect is easily visible and it's fast. Chicks take 21 days to develop from initial fertilization to hatching and we use the eggs for the 3 day to around the 10 day part of that cycle. I started writing this at 3pm and now it's after midnight. This working for a livi...

I work in cancer research and of late I've been investigating the affects of some chemicals on angiogenesis, particularly as it relates to breast cancer. Now I'm a technician, not a PI, so my nose is to the ground and I often miss the big picture since my concerns are oriented towards the day-to-day research. As a result, I often get tunnel vision and only look at cancer through the prism of my research. In this case that means that I frequently think of cancer as only developing when there's plenty of oxygen available--which is reasonable since as a fast dividing group of cells, a cancer tumor needs lots of energy which would seem to imply oxidative reduction, not glycolysis--which requires sufficient vascularization and thus angiogenesis. However the cancer picture is more complex than that and the Warburg Effect is one example of that. Some tumors actually preferentially grow in the absence of oxygen and use glycolysis as their primary source of energy. They do this by b...