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

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

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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