MARF Exposes Biased Misreading of New SV40 Research
August 24, 2000
New SV40 Study
On Tuesday, August 22, the Proceedings of the National Academy of Sciences published online a study regarding the controversial polio vaccine contaminant known as simian virus 40 (SV40), entitled, "Human mesothelial cells are unusually susceptible to simian virus 40-mediated transformation and asbestos cocarcinogenicity."
According to the study, mesothelial cells are much more susceptible than other human cells to transformation by SV40. Further, the study reports that SV40 appears to act synergistically with asbestos to transform mesothelial cells, thus indicating that SV40 and asbestos may be cocarcinogens. The report's conclusion, in its own words, is that "Malignant mesothelioma may be a new example of cocarcinogenesis between a virus (SV40) and a ubiquitous environmental carcinogen (asbestos)."
The purpose of the research, which has been funded jointly by the National Institute of Health (NIH) and the American Cancer Society, is to develop novel strategies for the treatment of mesothelioma patients. The research will provide the framework for future efforts to develop a viral antigen-targeting vaccine that can be used in a clinical trial for patients afflicted with this incurable cancer.
Distortion of Study in Favor of Asbestos Defense
Immediately upon publication of the study, HarrisMartin Publishing issued a press release which was picked up by PRNewswire and itself published nationally. Under the banner headline, "Study Appears to Eliminate Asbestos As Initiator of Mesothelioma Tumor," the article seizes on the study as a coup for the asbestos industry's defense of mesothelioma cases. No mention was made regarding the implications of the research on the development of a vaccine.
The article was replete with unfounded and irresponsible conclusions that were directly or impliedly attributed to Dr. Michele Carbone, who has spent the last several years researching the SV40 virus. The article described Dr. Carbone's study as "suggest[ing] that asbestos exposure is secondary to SV40 infection" in causing mesothelioma. It further denied the role of asbestos in causing mesothelioma, stating that according to Carbone, "exposing human tissue to asbestos actually destroys the mesothelial cells, preventing malignancy from occurring."
Quoting an asbestos defense attorney (and without any balancing statement from a patients' representative), the article concludes: "'[Mesothelioma] cases may now be medically defensible .... It would appear SV40 initiates cancer at the cellular level and that immunosuppression either from asbestos or other serious illness may allow mesothelioma to occur. But it's apparent that asbestos does not play a primary role.'"
MARF Steps In For Scientific Accuracy
The HarrisMartin article promptly drew the interest of The Mesothelioma Applied Research Foundation (http://www.MARF.org). MARF's mission is to eradicate mesothelioma as a life-ending disease, through raising awareness and funding research aimed at finding a cure. In this mission, MARF works closely with the relatively very few experts who are conducting research on novel mesothelioma therapies. The lack of interest is the result of many factors, one of which is that scientists have been reluctant to "get involved" because of the political and legal implications of the research and the fear of having one's character besmirched by unscrupulous advocates. To avoid any appearance of serving one side or the other in asbestos litigation, MARF does not support research into mesothelioma causation, whether by asbestos, SV40 or otherwise. In MARF's view, mesothelioma victims need neutral, scientific research that can be translated into meaningful therapy options; not research designed to make mesothelioma cases "medically defensible."
In view of the misleading statements made in the HarrisMartin article, MARF contacted Dr. Carbone, and discussed the article and the study with him in detail. The article's title, "Study Appears to Eliminate Asbestos As Initiator of Mesothelioma Tumor," and its statement that "asbestos exposure is secondary to SV40 infection in causing" mesothelioma are simply distortions.
Correct Reading of the SV40 Study
The study accepts as firmly established that asbestos causes mesothelioma. At the same time, it accepts (based on previous data, and without trying to prove) that in tissue culture, i.e., in vitro, asbestos does not "transform" mesothelial cells, i.e. it does not initiate or begin the malignant process of abnormal and continuous cell reproduction: "The role of asbestos in causing malignant mesothelioma has been firmly established epidemiologically; however, it has been difficult to reconcile the epidemiological findings with the inability of asbestos to transform mesothelial cells in tissue culture."
The study therefore examines transformation of mesothelial cells in tissue culture. It indicates that, again in vitro, SV40 is able to cause some mesothelial cell transformance, and that tissue culture exposed to both SV40 and asbestos results in much more transformation. (The study hypothesizes that this "may" result from the immunosuppressive activity of asbestos.) Thus the study concludes that SV40 may be a cocarcinogen, with asbestos, in causing mesothelioma. This does not prove that SV40 alone causes mesothelioma. This would require much more research, including in vivo animal studies. Nor does it eliminate asbestos as a cause or initiator of malignant mesothelial cell transformation. On the contrary, it shows that in vitro, asbestos combined with SV40 does cause transformance, significantly more than does SV40 alone.
Furthermore, the study recognizes that the way asbestos operates in isolated mesothelial cell culture in vitro does not fully describe the way it operates on actual human tissue, in vivo. Outside the petri dish, "asbestos induces the production of oxygen radicals by macrophages, which may promote gene alterations and carcinogenesis. Thus it is possible that in vivo, asbestos has stronger effects on carcinogenesis than in vivo." In its rush to exonerate asbestos as causing mesothelioma, the HarrisMartin article completely ignores this.
Dr. Carbone was most concerned about the statement attributed to him that "asbestos actually destroys the mesothelial cells, preventing malignancy from occurring." He called this "absolutely wrong." Asbestos is very toxic to mesothelial cells in vitro. However, this toxicity absolutely does not "prevent" malignancy from occurring. On the contrary, even in his in vitro study, asbestos with SV40 caused much more malignancy than SV40 by itself.
After MARF alerted Dr. Carbone to this misstatement, Dr. Carbone called HarrisMartin and asked them to correct it. Yesterday, HarrisMartin re-issued the article, deleting the paragraph regarding asbestos' supposed prevention of malignancy.
The True Story
Whether or not asbestos fibers alone "initiate" tumorigenesis, contrary to the asbestos defense lawyer's interpretation, the Carbone article does not alter 50 years of science which supports the conclusion in the legal arena that asbestos "causes" mesothelioma.
It is unfortunate that in its zeal to defend the asbestos industry, HarrisMartin misread the study and completely missed the point. The real point of the study, and of this story, is that if indeed the virus can be associated with mesothelioma, then developing an anti-SV40 vaccine might be worthwhile. This would provide life saving therapy for mesothelioma patients, which indeed is the ultimate goal. MARF applauds those doctors who despite the lack of funding and the risk of character assassination go to work every day, carefully adhere to the scientific method, and pursue the ultimate truths.