By IANS
New York : Can cancer be successfully treated as an infectious disease? The answer, according to a team of researchers at the Albert Einstein College of Medicine here, is yes.
The team has shown for the first time that cancers can be treated by targeting viruses that cause them.
This raises the possibility that the virus-infected cells can be destroyed before they turn cancerous, reports PloS One, an open access science web site.
The researchers used a technique called radioimmunotherapy, in which radioisotopes are piggybacked on to antibodies. Once these precision-made molecules are injected into the body, the antibodies home in on a specific protein target, and the radioisotope “warhead” destroys the cell to which the protein is attached, the web site reported.
Nearly 20 percent of human cancers worldwide are caused by pre-existing virus infections.
Prime examples are liver cancer (caused by hepatitis B and C viruses), cervical cancer (caused by human papillomaviruses) and certain lymphomas (caused by the Epstein-Barr virus).
But while antigens on the surface of cells are susceptible to attack by antibodies, the viral antigens associated with cancers typically lurk inside infected cells. So scientists had assumed that antibodies couldn’t reach them.
“We had a hunch that rapidly growing tumours can ‘outgrow’ their blood supply, resulting in dead tumour cells that might spill their viral antigens amongst the living cancer cells,” said Arturo Casadevall, Forchheimer Professor and Chair of Microbiology & Immunology at Albert Einstein College of Medicine and co-senior author of the study.
“So we hoped that by injecting antibodies hitched to isotopes into the blood that they’d be carried deep into the tumour mass and would latch on to these now-exposed antigens. Then the blast of radiation emitted by the radioisotope would destroy the live tumour cells nearby.”
“Virus-associated cancers account for some 1.3 million cancer cases each year, so the need for new strategies in treating them is obvious and urgent,” said Ekaterina Dadachova, the study’s other senior co-author.
“Our study has shown in principle that radioimmunotherapy can help in treating cancers caused by viruses-and, just as exciting, the approach also holds promise for cancer prevention.”