Subject: Metastasis vs Implantation

From: [email-masked] (Eleanor)
Date: 19 Aug 93 16:08:55 GMT

Hi all!  I haven't seen any discussion going on here and since I have
a question, thought I'd ask it.  So, when a mouse (or other organism)
has a known primary tumor and also several secondary tumors, is there
any way to determine whether the cells which developed into the
secondary tumors had metastasized (gone through the vasculature) as
opposed to simply breaking off and migrating to the secondary site
(such as through the abdominal cavity).  And to throw an even bigger
wrench into the situation, is there any way to determine whether a
"secondary" tumor originated from the primary tumor or from a "previous"
secondary tumor?

Thanks for any and all responses!

Eleanor Gallo-Hendrikx
Dept of Molecular Biology & Genetics
University of Guelph
Guelph, Ontario, Canada N1G 2W1
email: [email-masked]

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From: [email-masked] (Stephen Gisselbrecht)
Date: 19 Aug 93 14:05:28 EDT

In article <[email-masked]> [email-masked] (Eleanor) writes:
>So, when a mouse (or other organism)
>(such as through the abdominal cavity).

	Wow, this is a hard one.  Ah, the best I can think of would be to
look and see if the secondary tumor cells are expressing "metastasis
proteins".  This is made more difficult by the fact that we're only
beginning to know what metastasis proteins are, but I would look at what
proteases they express, what adhesion molecules, look for vascular
permeability factor, heparinases and those sorts of things.  Of course,
you'd have to look at some secondary tumors that were known to have
developed by migration, to ensure that they don't express the same
markers. 

>And to throw an even bigger

	I would think this one would be easier.  With all the genetic
instability of tumor cells, I wouldn't be surprised if you could answer
this just with karyotypes.  If all tumors have abnormalities A, B, and C,
then you can probably assume that they were present in the primary tumor
before malignancy.  If there are some abnormalities that are present in
two or more tumors, but absent from the primary, I would bet that means
that all but one of those other tumors is tertiary (or even more removed).
Deciding which one could probably be done this way too, since I would
expect that one of the tumors would appear "closer" to the primary than
the others.
	Is this all garbage?  Does anyone actually know if this would
work?  I'm just guessing here.

>Dept of Molecular Biology & Genetics

					steve gisselbrecht
					cell & dev. bio.
					harvard medical school