More on EBV and myeloma stem cells

A few months ago, before all the kitten chaos began in our lives (read: when I had a bit more free time!), I came across a 2013 Johns Hopkins University Ph.D. thesis titled “Persistence of EBV in the cancer stem cells fraction of multiple myeloma,” by Sunetra Biswas. [Reminder: EBV is the acronym for Epstein-Barr Virus, about which I’ve written a bunch of posts, most recently in October 2017…A connection has finally been established between EBV and MM in SOME patients.]

I began reading, and drafting a post about, Dr. Biswas’ thesis, which is very interesting but also quite technical here and there…well, okay, it’s technical everywhere 😉 Now, I might repeat some stuff, but that’s because there are some repetitions in the thesis, as you will see if you are brave enough to go have a peek. I apologize for the repetitions…I just took one out, in fact, and I’ve only re-read this post at least five times! 😉

Here’s the link:

In the abstract, Dr. Biswas states that “EBV is present in some multiple myeloma cell lines and patients and when present, it is detected in a subpopulation of cells.” This subpopulation has “a mature B cell phenotype.”

But EBV just doesn’t sit inside the cell and do nothing. Nope, it helps MM cells grow.

However, check this out: when EBV is taken out of the MM cells (using a viral inhibitor), their growth slows down. On page iii, she talks about the growth of myeloma STEM cells. Oh how I wish I’d known all this when I became infected with EBV, decades ago!!! This viral inhibitor business gets reiterated on Page 8, btw.

On Page 2 of the Introduction, she states something that I already knew (but reminders aren’t a bad thing, eh): some B-cells infected by EBV become IMMORTAL. Just like cancer cells.

On Page 8 she begins looking at multiple myeloma and at myeloma stem cells, and then states that her research “suggests that EBV persists in cancer stem cells in MM patients and in four out of seven commonly studied MM cell lines.” More than half…wow.

Further on, Dr. Biswas states what we already know: “Multiple myeloma is a neoplasm of the plasma cells that has not been previously shown to be associated with EBV.” Indeed, in the past, whenever I asked a MM expert about this possible connection, all I got were denials and eye rolls. Well, now we have more than one study showing that there IS a connection…for SOME of us, at least.

Can’t be denied now. No more eye rolls expected… 😉

Now, even though she “identified EBV in 4 out of 7 multiple myeloma cell lines, EBV wasn’t present in every single myeloma cell, but only in a subset of cells, that is, a small population of cells, which makes it different from other EBV-caused cancers. And yes, the subset of cells happen to be myeloma stem cells.

Time for a mind-boggling statistic: the B-cells of 90% of the world’s population are infected with EBV. So here’s a good question: since Epstein-Barr is such a common viral infection, why don’t more people have myeloma or other types of cancer associated with an EBV infection? Clearly something else must be going on, otherwise practically everyone in the world would have some sort of EBV-associated cancer…

There must be other factors involved for an EBV infection to lead to MGUS and so on…

I hope to find the answer to that question by the end of this post (but I may not…there may be no answer as of yet), which I am going to divide into “chapters”…although if I skip a lot of the technical stuff, and the repetitions, I might end up with less material than originally planned… 😉 …

Oh, okay, drat, Pixie and Pandora have woken up from a nice cat nap and are becoming way too interested in what I’m doing at the computer, so I have to stop for today…Meeeeow! I mean, Ciao! 🙂