July 28, 2006, 11:33 am
A New Dimension to Cancer Research
By Lisa Agustin
New research at MIT indicates that there may be a better way of evaluating anti-cancer therapeutics. Currently, pharmaceutical companies use simplistic two-dimensional assays, or tests, to measure success in stopping metastasis, the process by which cancer cells break away from the primary tumor, settle in a new location, and divide. Researcher Muhammad Zaman discovered the cells move differently in three dimensions:
“Two-dimensional assays ignore the obstacles that cells face in their natural contexts,” said Zaman. “In 3-D, cells move through a thick jungle of fibers, or ‘vines,’ that hinder forward progress.”
Cells need at least some vines to move, as they latch onto the “branches” with claw-like proteins called integrins and pull themselves forward. When Zaman disabled some of these claws, in a manner analogous to the workings of certain anti-cancer drugs, the cells moving across the top of the jungle canopy (in two dimensions) needed a greater number of vines to keep up their pace, while cells plowing through the jungle instead needed fewer vines to maintain the same speed.
For his 3-D study, Zaman worked with one sample at a time, using a special confocal microscope at the Whitehead-MIT BioImaging Center to divide each specimen into virtual slices, generating a new stack of images every 15 minutes. According to MIT Professor Paul Matsudaira:
“[Zaman's] computational model predicted what would happen in virtual experiments and then he was able to go straight to test the predictions with these complicated 3-D experiments. As a result, the sophisticated models of cell movement enhance our understanding of key biological processes, including metastasis.”
