'DNA origami' tackles multidrug-resistant cancer cells
28 November, 2018
A DNA tool that combines gene therapy with chemotherapy could be a promising new way to defeat multidrug-resistant cancer cells.
The tool is a "tailored DNA nanoplatform" that can carry chemotherapy drugs into targeted cancer cells while also silencing the cells' drug-resistance genes.
The technique is the work of scientists at the National Center for Nanoscience and Technology in Beijing, China.
A recent paper in the journal Angewandte Chemie International Edition gives a detailed account of how the team developed and tested the DNA nanoplatforms.
Drug treatments have significantly improved rates of survival and quality of life for people with cancer.
However, there are many cases in which cancer responds well to treatment at first but then relapses or comes back because of drug resistance.
Drug efflux
Scientists have identified several cell mechanisms that enable or promote drug resistance in cancer.
One of these is "drug efflux," a process in which transporter proteins pump drugs out of the cell body through its membranes. Efflux mechanisms exist "in all living cells," not just cancer cells.
For example, cells in the walls of the gut have an abundance of transporter proteins that pump drugs and other harmful agents back toward the digestive tract.
Thanks to extensive research, scientists now know a lot about the role of efflux mechanisms and transporter proteins in developing drug resistance in cancer.
One of the first transporter proteins that they identified was one that is coded by the Multi-Drug Resistance Gene 1 (MDR1).
Studies have also revealed that when certain organs become cancerous, their tissues start to express MDR1 more strongly.
One study, in particular, discovered that treatment with the potent anticancer drug doxorubicin greatly increased expression of MDR1 in cancerous cells but not healthy cells of the lung.