Just to make this clear up front:
WHAT I AM ABOUT TO WRITE ABOUT IS NOT A 'CURE' FOR CANCER. ITS A NEAT IDEA WE MIGHT BE ABLE TO CAPITALIZE ON IN THE FUTURE. ITS COOL! NOT A 'CURE'.
Perfect example of the potential domesticated viruses have to tame deadly diseases!
Tumor Cell Marker PVRL4 (Nectin 4) Is an Epithelial Cell Receptor for Measles Virus
... only the human tumor cell marker PVRL4 (Nectin 4) rendered cells amenable to measles virus infections... It is highly expressed on many lung, breast, colon, and ovarian tumors suggesting that they could be targeted with oncolytic measles virus.
Some of the measles viruses we use in the lab and in vaccines, they dont behave 'normally'. Its not in an 'Outbreak'-like bad way-- its more like they had a 'posh' upbringing in the lab, while their 'natural' relatives had a much harder life. Because they grew up with a silver pipette in their measle-mouths, they had the luxury to explore options untamed viruses couldnt. We capitalize on this, on purpose, to attenuate viruses for use in vaccines.
But there was a neat side-effect with measles. Maybe because we grow viruses in cell lines in the labs, and cell lines are kinda like tumors, some measles viruses can use a protein, PVRL4, on the surface of some tumors to initiate infection. PVRL4 is a totally normal human protein that is expressed in certain cells at certain times. But cancers are all kinds of messed up. They behave in ways 'normal' tissue shouldnt, and they likewise make proteins they arent supposed to make, like PVRL4.
So some kinds of measles can use PVRL4 to infect cells... and well, measles kills the cells it infects... including the tumor cells! Especially adenocarcinomas, apparently! Its not that we could use measles to deliver an anti-cancer drug or gene to tell the tumor to commit suicide or something-- measles is naturally lytic, thus 'naturally' oncolytic! It just kills the cancer, all on its own.
This paper was very thorough in determining the receptor measles was using to perform this trick, and figuring out which cells measles could be used on. But it is all just in cells in the lab. Lab â Real World Therapy.
But other folks have been trying it out in animal models! Mice that have been grafted with human tumors! And according to those authors, 'Clinical trials using vaccine measles virus (MV) as anticancer therapy are already underway.'
I have no idea how those clinicians are getting around the fact everyone has antibodies to measles (if your immune system kills measles before it can kill your tumor, hows it gonna work?), but I cant wait to see how this turns out!
I know nothing about viral engineering, but is there a way to engineer a measles virus so it both infects cells expressing that protein, and also is not recognizable as measles by the immune system? That sounds like almost like a silver bullet, but I don't know if that's at all possible.
By the way, I meant infects only cells expressing that protein.
I was wondering about modifying the virus too. I guess it just depends upon how our antibodies to measles behave, but in that case there's a big question as to how rapidly we would develop an immunity to the cancer-killing virus, so that it might not be that effective.
Then I thought about a potential other option: maybe we could give people immunosuppressive drugs? That sounds dangerous as hell, but at least you can take people off of the immune suppressants, and you can test the virus on a tissue sample to see if it works first.
YEAH!!! CURE FOR CANCER!!!1!!
off to smoke and tan
SWEET! We all saw it here first. 100% definitive cure for all cancers! Now I can finally pursue my dream of bathing in Mt. Dew!
Well, at least a cure for cancer in under two year olds who didn't have their MMR shot yet.
This is what I love about this blog. Information from the trenches of basic research that I don't hear from anywhere else.
BTW, I loved your discussion on Vince's podcast.
Ok, the e-mail about this post *just* showed up. 10 hours travel time from your neck of the woods to mine I suppose.
This all very interesting stuff. I'll definitely pray about it tonight. I'll let you know if that turns up any leads.
I have half a mind to e-mail this to Jenny McCarthy to see if I can get that rocket surgeon to make mention of how not vaccinated one's children might be useful in later in life fighting cancer. Screw that autism angle, this will sell the product much, much better. Besides, I'd love to see you pull a, "I'll call you dentist Horowitcz" type move on that nutter.
Alas, it would do no good. Here's a taste of what passes for mental ability worth her endorsement, as it relates to the 'National Childhood Vaccine Injury Act', taken from a Texas department of something another whatever,
Damages were awarded, often without scientific evidence to support vaccine injury claims.
Anyway, I digressed a little. Abbie, to the direct question, if the vexvaxers have their way, your last pondering will be moot. Of course, not vaccinating in addition to potentially opening up some treatment lines for cancers will also directly reduce the number of cancers developed. Dead kids, turns out, don't grow up to get cancer. Who knew.
Hey Abbie,good post. Glad to see some measles attention going on. Check out the post I put up covering this paper (I kind of didnt mention the whole cancer side..). But my group is heavily involved in measles research and this discover was a big deal for them.
I think when developing an anticancer virus you need to "retarget, arm and shield" the engineered virus. (see review - http://www.ncbi.nlm.nih.gov/pubmed/18552863). One way of re-targeting measles is by making chimeric envelope proteins with a closely related non-human virus, like canine distemper virus.
The furthest they have got with anticancer measles: http://www.ncbi.nlm.nih.gov/pubmed/21610701
Just this morning I was reading a poster about someone coming to my institute to give a talk on this in a couple weeks. I don't do viruses or cancer, but this looks cool.
Ins't this the plot to the movie I Am Legend? I think I'm going to stock up on water and dry goods. Stay away from me if you get sick or if you develop a fear of sunlight.