Investigators and patients alike look forward to the day when it will be possible to correct the effects of abnormal genes by supplying the body with normal ones. Gene therapy refers to the treatment of a genetic disorder by inserting normal genes into abnormal cells. The hope is that the transferred genes will cure the basic defect rather than merely alleviating its damage.
Getting sufficient amount of the normal gene to use in the treatment was not a stumbling block. Hundreds of human genes have been cloned by recombinant DNA techniques. The major problem is however putting the normal DNA into cells of the patient so that it can be integrated into the human body, followed by production of the required normal protein.
One approach towards gene therapy is the packing of the corrected gene material into a virus (Retrovirus) and then injecting it into the diseased cells. A new virus based gene therapy has been developed by Mayo Clinic research team to help fight cancer. The finding is expected to provide an answer to the hurdles existing regarding gene therapy for cancer.
The approach relies on particles called as "therapeutic hitchhikers", derived from retroviruses (RNA-containing viruses that incorporate into the genomes of infected cells and then produce a therapeutic gene).
T cells are the immune system's major line of defense against tumors. The viral particles attach to a specific kind of T cell in the immune system and "hitchhike" to the tumor. By hitching a ride on the T cells, the therapeutic particles can hit their tumor target while avoiding detection (and destruction) by the immune system.
Experiments carried out on similar grounds in mice using human and mouse cancer cells, have been associated with significant cure rates of metastatic or spreading tumors. Autoimmune disorders or those with inflammation are other potential areas where the approach would be helpful.
"Our work is an important contribution to the maturation of the field of gene therapy because ultimately treating cancers by gene therapy depends on scientists' ability to specifically target tumor cells in the patient -- and this specific-delivery feature has eluded researchers for a variety of reasons. But by devising a way for viruses to hitch rides on antigen-specific T cells, we've been able to get over multiple obstacles to gene therapy", according to the investigator.
The work is still at an experimental phase and has to undergo large scale refinement before it can be validated for human beings.