Researchers led by ETH Zurich professor Yaakov Benenson and MIT professor Ron Weiss have incorporated a diagnostic biological “computer” network in human cells.

This network recognizes certain cancer cells using logic combinations of five cancer-specific molecular factors, triggering cancer cells’ apoptosis (destruction).

The long-term goal is to construct biocomputers — biological computers that operate in living cells and detect molecules carrying important information about cell wellbeing, and then process this information to direct appropriate therapeutic response if the cell is found to be abnormal.

In a study published in Science, the researchers describe a multi-gene synthetic “circuit” whose task is to distinguish between cancer and healthy cells and subsequently target cancer cells for destruction.

This circuit works by sampling and integrating five intracellular cancer-specific molecular factors and their concentration. It combines the molecular factors using a prescribed molecular “program” and gives a diagnosis.

This, according to Benenson, represents a significant achievement in the field: “We are still very far from a fully functional treatment method for humans. This work, however, is an important first step that demonstrates feasibility of such a selective diagnostic method at a single cell level.”

Ref. Zhen Xie, et al. Multi-Input RNAi-Based Logic Circuit for Identification of Specific Cancer Cells, Science 333, 1307 (2011);