FW: NCRP 136 / Immunology, DNA repair, cancer...

["Dukelow, James S Jr" <jim.dukelow@PNL.GOV>]

I am resending this because it appears the previous transmission did not

reach RADSAFE.  Of course, the alternative conclusion is that everyone read

it and said "Ho-Hum".



Best regards.



Jim Dukelow

PNNL



-----Original Message-----

From: Dukelow, James S Jr 

Sent: Tuesday, October 23, 2001 11:36 AM

To: 'Bjorn Cedervall'; radsafe@list.vanderbilt.edu

Subject: RE: NCRP 136 / Immunology, DNA repair, cancer...







After providing a bunch of evidence for his position, Bjorn wrote:

-----Original Message-----

From: Bjorn Cedervall [mailto:bcradsafers@HOTMAIL.COM]

Sent: Tuesday, October 23, 2001 10:32 AM

To: radsafe@list.vanderbilt.edu

Subject: RE: NCRP 136 / Immunology, DNA repair, cancer...



   <snip>



In order for the immune system to function on a cellular level there must be



antigens that the immune system can react against. These antigens must in 

some way be "specific" to the tumor. In principle there are no such specific



antigens (an exception is for testis tumors where certain antigens are 

immunologically invisible in the healthy individual).



   <snip>



Therefore, I don't think that the immunology has any important role in the 

protection against cancer.



For clarification: DNA repair is not a function relating to immunology.

Induced DNA repair or protection (could be phycico-chemical in nature) can 

be induced however but that is another issue.



My personal opinion,



Bjorn Cedervall    bcradsafers@hotmail.com

http://www.geocities.com/bjorn_cedervall/



===================



Offering my non-expert opinion, I have some problems with this position.



Immune deficiency diseases and congenital immune deficiencies seem to be

associated with increases in incidence of cancer.  Alcamo's Fundamentals of

Microbiology has (p. 412) regarding HIV: "As described previously, patients

with HIV infection suffer a gradual decline of helper T-lymphocytes together

with an increase in viruses.  This combination allows for continued immune

deficiency and the development of opportunistic diseases and cancers."  A

paragraph or two earlier, Alcamo lists some of the "opportunistic" cancers:

" ... secondary cancers, Kaposi's sarcoma (KS), non-Hodgkin's lymphoma, and

primary central nervous system lymphoma."  A bit further down, he notes the

CDC's 1 Jan 1993 redefinition of AIDS added three new conditions to the

definition of progression of HIV infection to AIDS, including "invasive

cervical cancer".  I am not aware of any effect of HIV infection on DNA

repair, which suggests that this increased susceptibility to cancer is

related to the immune deficiency.



Regarding expression of antigens on the tumor cells surface:  I thought that

one of the features of many tumors was the modifications of cell adhesion

properties, which are probably implemented by changes to the cell surface.



Finally, my understanding of Evo-Devo dogma is that the immune system is

designed as one of the lines of defense against cancerous cell changes

(mopping up after DNA repair failures).  Another part of the dogma is that

evolution doesn't affect (doesn't care) about what happens to people/animals

after reproductive age.  In our case, immune system function gradually

declines in older humans and, I believe more than coincidentally, cancer

incidence increases.



Best regards.



Jim Dukelow

Pacific Northwest National Laboratory

Richland, WA

jim.dukelow@pnl.gov



These comments are mine and have not been reviewed and/or approved by my

management or by the U.S. Department of Energy.

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