Cancer vaccines: a step towards prevention and treatment of cancer.

Breakthroughs in basic science and applied biology over the last quarter of a century have had a great deal of influence on our understanding of disease processes. The structure, function and importance of various lipid and protein molecules within cells is now well known and is central in future developments of diagnostic and therapeutic modalities. Since the discovery of the double helix DNA structure by Watson and Crick, molecular biology has come a long way enabling inroads to be made in manipulating DNA and evolving into the discipline of molecular oncology. For tumours having a viral carcinogenesis, preventive vaccines directed against viruses reduce the chance of tumour formation. Therapeutic vaccination, on the other hand, is less successful. To overcome the latter, various methods involving the use of tumour-specific antibodies, anti-idiotypic antibodies, peptides, proteins and carbohydrate products of human tumours, etc. have been tried. However, as the majority of human tumours are antigenic and not immunogenic, the problem remains. Recently, inoculation with DNA plasmids, encoding a variety of proteins, has been able to generate T-cell specific responses in vivo. This novel concept may help scientist to overcome the immunological tolerance and anti-tumour ineffectiveness induced by many human cancer cells and may lead to generation of tumour-specific vaccines.