Scientists Hack a Human Cell's DNA and Turns It Into a Biocomputer

Talk about weird headlines. This story veers a bit outside my usual interests, but is enough of a headscratcher that I had to give it a double take.

To set the scene: in what's probably the most evil-movie-scientist-wants-do-rewrite-life research field, scientists are trying to synthesize life from scratch. Yup, welcome to the field of synthetic biology, where international teams of brainiacs are hard at work trying to rewrite nature's software: DNA. 

Synthetic biologists operate on a basic idea: in order to truly understand something, we need to be able to build it ourselves. The overall goal is to understand and manipulate DNA to the point we can get any cell or any organism to do what we want. An even grander goal is to build lifeforms that don't naturally exist--microorganisms that run on silicon, not carbon; bacteria that can photosynthesize; cells that can turn into whatever type of tissue on demand.

This study is the latest towards engineering cells that respond to our needs. In a nutshell, scientists found a way to control added bits of DNA so that only certain logical operations result in the cell outputting a certain command. This is a bit hard to explain, so picture wiring an electrical circuit board that controls a lightbulb--your goal is to have it light up only when some conditions are met.

In the cell's case, the "lightbulb" is a protein that glows green under UV light. Human cells don't naturally produce this protein (called GFP - green fluorescent protein), but with gene editing we can hack it into a cell. 

Normally, a cell will happily follow its operating manual - it's DNA - and synthesize GFP. However, the scientists then put another small strand of DNA in front of GFP that tells the cell to stop. This is essentially a NOT gate in Boolean logic: don't do something.

Still with me? There's more. The scientists then zoomed in on a class of proteins called DNA recombinases that can snip DNA strands and fuse open ends back together. The team focused on one type of DNA recombinase that can cut out the stop sequence (the NOT gate). They then engineered these proteins to only activate when they give the cell a drug.

So the logic gates work like this: if there is no drug, the DNA scissors are not active, the NOT gate remains, and the cell does not glow. Else, if there is the drug, the DNA scissors active and snip out the NOT gate, the cell then glows.

That's the simplest example of the over 100 logic gates that the scientists built. They even programmed the cell to obey a 6-input Boolean logic table, which is really quite remarkable because biology is a hell lot messier than computer programming.

You may be asking: what's the point? 

The end goal isn't to have powerful cellular computers (although if a whole body's worth of cells solve logic problems simultaneously that would be pretty cool). The goal is to show that there's now a way to very reliably hack into a human cell's DNA and tell it to do something if it meets certain requirements.

For example, scientists may program an immune cell to identify cancer biomarkers, and only attack a potential cancerous cell when it detects multiple markers (if-then plus AND gates). This would enhance our bodies' ability to hunt down early tumors long before a doctor can make a diagnosis, but also add an extra layer of protection so that the immune cell doesn't go after a normal cell.

Find more of details about the story here.