Scientists at Emory University and Case University of the Western Reserve Region in the United States have created a new effective way of delivering molecular bombs to metastatic cancer cells that begin to appear in the last stage of cancer growth. Experts have modernized adenoviruses, making them elusive for the immune system. This is reported in an article published in the journal Science Translational Medicine.
Oncolytic viruses are used to kill cancer cells, and in 2015 the FDA approved the virus against melanoma. At the same time, with metastatic cancer, this method becomes ineffective due to the fact that the immune system quickly destroys the viruses introduced into the blood. The modified adenovirus Ad5-3M does not cause a massive inflammatory response, so it is able to spread throughout the body, looking for metastatic cells.
The changes were introduced into the adenovirus at three locations to minimize the interaction of the virus with certain blood factors. Thus, artificial mutations affect that part of the adenovirus that interacts with immunoglobulin M. This prevents the inactivation of the virus and its capture by liver macrophages. A sequence was also added to target Ad5-3M to tumor cells.
When mice were given high doses of standard adenovirus, liver damage and death were observed within days, and the modified virus was found to be safer. The disappearance of tumors and an increase in life expectancy were observed in 35 percent of the experimental mice.