Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

No role for simian virus 40 in human pleural mesotheliomas

24.09.2004


Mesothelioma is an aggressive cancer of the chest cavity that kills about 2000 people a year in the United States. Seventy to eighty percent of patients with this rare cancer have had exposure to asbestos. It has also been proposed that simian virus 40 (SV40), a contaminant in some polio vaccines administered in the 1950’s and 1960’s, might be a cause. However, studies reporting the detection of SV40 DNA in human tumors (including mesotheliomas, and also some lymphomas, brain cancers, and bone cancers) have not consistently yielded the same results when repeated by other groups. This has fueled an ongoing debate over laboratory methods and the strength of the association of SV40 with these tumors.



A study, published in the September 25 issue of Lancet, calls into question this proposed link between SV40 and pleural mesothelioma and provides a possible explanation for the discrepancies in the results obtained by different groups. Researchers at Memorial Sloan-Kettering Cancer Center (MSKCC) used several independent methods to detect SV40 DNA, SV40 RNA, and SV40 proteins in human pleural mesothelioma samples and found no evidence for a significant role for SV40 in human mesotheliomas. Unexpectedly, they found that the SV40 DNA fragments detected in some assays were not derived from genuine SV40 in the tissue samples but from SV40 DNA fragments engineered into common laboratory plasmid vectors used in molecular biology research. This source of SV40 DNA fragments may be unrecognized, leading to misinterpretation of assay results as indicating the presence of genuine SV40 in human tumors. Their findings are a caution to other researchers to be vigilant in avoiding these technical errors when planning future studies with SV40.

"Because SV40 was a recognized contaminant of some polio and adenovirus vaccines in the 50’s and early 60’s, its potential to cause cancer in humans has been a source of intense debate since the apparent detection of SV40 DNA in some human tumors was first reported," explained Fernando Lopez-Rios, M.D., of the Department of Pathology and the study’s lead author. "An important aspect of our study was that the availability of frozen mesothelioma tumor samples allowed us to search for SV40 RNA (an expected product of functional SV40 DNA), which has never been studied in a large series of mesotheliomas, and to show that it is completely absent."


Their study presents multiple lines of evidence against the proposed link between SV40 and human mesotheliomas. As part of their ongoing research into the biology of human pleural mesothelioma, this team of MSKCC investigators searched for SV40 DNA, RNA, or protein in frozen tissue samples from 71 human pleural mesotheliomas. According to the study, the methodology used by most researchers for the detection of SV40 DNA is associated with a high risk of false positive results. Therefore, the authors propose that data on SV40 in human tumors need to be carefully re-examined.

"Our previous work on mesothelioma showed that about 80 percent of tumors have lost both copies of the tumor suppressor gene designated p16 or CDKN2A, and this led us to ask whether SV40 infection might be a possible mechanism in the remaining 20 percent," said Marc Ladanyi, M.D., Director, Diagnostic Molecular Pathology Laboratory, and the study’s senior author. "But instead we found no evidence for SV40 in these tumors and our experiments show for the first time how the assays commonly used to detect SV40 DNA in human tumors are uniquely prone to false-positive results. We hope these results will hasten progress on this deadly cancer."

Joanne Nicholas | EurekAlert!
Further information:
http://www.mskcc.org

More articles from Life Sciences:

nachricht Nanotubes built from protein crystals: Breakthrough in biomolecular engineering
15.11.2018 | Tokyo Institute of Technology

nachricht Insect Antibiotic Provides New Way to Eliminate Bacteria
15.11.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland

15.11.2018 | Earth Sciences

When electric fields make spins swirl

15.11.2018 | Physics and Astronomy

Discovery of a cool super-Earth

15.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>