Researchers at the University of Zurich have developed a virus-based therapy that causes a tumor to destroy itself. They modified an adenovirus, which is a common virus that typically infects the respiratory tract and which is already widely used in medicine, to deliver genetic material that codes for an anti-cancer protein. In a sneaky move, the researchers designed the therapy so that the virus would infect tumor cells, forcing them to destroy themselves. Cancer therapies are constantly evolving. Immunotherapies, which include antibodies that stimulate the immune system to destroy cancer cells, are the latest class of therapy in the fight against cancer. Immunotherapy aims to be more selective and produce fewer side-effects than conventional chemotherapy agents. However, side-effects are still an issue, and more localized therapies would be welcome. This latest technique aims to be more localized, and involves stimulating the target cells so that they produce therapeutic proteins at precisely the area they are needed – the tumor. “We trick the tumor into eliminating itself through the production of anti-cancer agents by its own cells,” said Sheena Smith, a researcher involved in the study, via a University of Zurich announcement. “The therapeutic agents, such as therapeutic antibodies or signaling substances, mostly stay at the place in the body where they’re needed instead of spreading throughout the bloodstream where they can damage healthy organs and tissues,” added Andreas Plueckthun, another researcher involved in the project. The technology combines an adenoviral vector typically associated with gene therapy or vaccines, but the genetic payload encodes an anti-cancer antibody, trastuzumab. The researcher team call their system SHielded, REtargetted Adenovirus (SHREAD), and it incorporates various elements they have previously developed for adenoviral vectors, including the ability to target them to specific tissues based on cell surface markers, and help them to avoid the immune system. So far, the researchers have tested the system in mice, and showed that the viral vector resulted in significant levels of trastuzumab production in target tissues. Excitingly, the system may have relevance in treating other diseases where localized production of protein therapies is desired, including COVID-19. Adenovirus is already being deployed in COVID-19 vaccines. “By delivering the SHREAD treatment to patients via an inhaled aerosol, our approach could allow targeted production of Covid antibody therapies in lung cells, where they are needed most,” said Smith. “This would reduce costs, increase accessibility of Covid therapies and also improve vaccine delivery with the inhalation approach.” Source
