Signal molecule holds possible key to tumour growth
non-Hodgkin's lymphomas has been identified by scientists whose
studies into cancer immunity in chickens could pave the way for an
effective drug therapy to treat one of the most common cancers of
the lymphatic system.
The discovery represents a giant step forward in the research and development of these forms of cancer. Previously, humans present in the late stages of Hodgkin's and non-Hodgkin's lymphomas could only be studied. In this model the potential is there to induce the lymphomas and follow them through from their earliest stages.
Through their work on Marek's disease virus (MDV), scientists from the Institute for Animal Health (IAH) identified many many biological properties with Epstein-Barr virus (EBV), a major cause of Hodgkin's disease. Infection with these herpes viruses can lead to lymphoma formation, which is closely linked with the over-production of a cell-surface molecule called CD30.
Dr Shane Burgess, lead researcher of the study told DrugResearcher.com: "For the first time we have detected the presence of specific antibodies against CD30 after MDV infection in MD-resistant chickens."
"The presence of CD30-specific antibodies suggests anti-tumour immunity may exist in Marek's disease, and perhaps also in some Hodgkin's and non-Hodgkin's lymphoma patients."
CD30 also promotes the survival of normal lymphocytes, essential for immune responses, and can also influence cell death. However, over-expression of CD30 is associated with the survival of lymphoma cells.
"We have shown that the chicken CD30 gene resembles the ancestral form of the human CD30 gene structure, and we have developed a new understanding for how this model has evolved in mammals, including humans," commented Dr Fred Davison, head of avian immunology at IAH.
"CD30 over-expression is evolutionarily conserved, and we think that this molecule is part of a critical cell signalling pathway that is disturbed during the formation of many different lymphomas."
Burgess and his team now hope to take this information and start looking into producing a drug or gene therapy to prevent the over expression of CD30. Other approaches on the agenda include vaccination as well as chemotherapeutic options.
"While there has been interest from a pharmaceutical company on one aspect of this work, we still have more fundamental research with this model to do," he commented.
The paper 'Marek's disease is a natural model for lymphomas overexpressing Hodgkin's disease antigen (CD30' by S.C. Burgess and colleagues is published in the early on-line edition of the Proceedings of the National Academy of Sciences, 06-10 September 2004.
