Scientists have used the bacteria responsible for the deadly disease anthrax to deliver important drugs to combat cancer cells. The bacteria known as the Bacillus anthracis have an efficient way of delivering their toxic proteins inside cells thereby causing the infection. So, the researchers have rendered the anthrax toxins harmless and instead made them vehicles for the required drugs.
As diseases like cancer are wreaking havoc in our societies, finding ways to tackle the problem is getting more and more pressing. One of the ways of doing so is to administer effective drugs to the patients suffering from cancer. The challenge in this case is to have efficient drug-delivery methods so that the substance needed to combat the cancerous growths can reach its required destination for it to have the desired effect. A team of scientists have worked on a new strategy to deliver cancer drugs successfully into cells. They have used the delivery system of the bacteria of species Bacillus anthracis as model.
Bacillus anthracis is able to potently inject toxic proteins into cells via a very elaborate cell machinery thereby causing the deadly disease anthrax. The researchers have focused their efforts on the way the bacteria deliver those proteins to use as delivery system for drugs. Bear in mind that this demands getting across barriers at the microscopic cellular level, hence the more taxing. Making manufactured proteins pass through the cell membrane of the target cells is greatly challenging; as a result, finding an organism that already has an inbuilt efficient delivery system is even more beneficial.
“Anthrax toxin is a professional at delivering large enzymes into cells,” says Bradley Pentelute, one of the authors of the paper.
The researchers therefore planned to turn the anthrax toxin into a harmless version in order to use it as portal to leave antibody drugs inside cells. The antibodies to be delivered were in fact two proteins which were antibody mimics with the ability to get rid of cancer cells by interfering with certain proteins.
How does the anthrax toxin work?
The toxin consists of 3 major parts. One of them is a protective antigen (PA). The latter binds to receptors found on the surface of cells. The binding produces a site where 2 other anthrax proteins – the lethal factor (LF) and the edema factor (EF) – can be pumped into the cells. When this happens, the proteins eventually trigger the cell’s death.
The same thing was done to deliver the necessary proteins. The LF and EF were made to include the antibody mimics instead of their toxic components. In this way, the useful proteins were made to enter the cells through the entry made by the PA.
Method could be reproduced for other diseases
The study marks the first whereby antibody mimics have been successfully delivered into cells. This will potentially open the door to many other benefits: new drugs for cancer as well as for other diseases might be developed and delivered in this way.