Metastasis is the word no one with breast cancer (or any form of cancer really) wants to hear. Metastasis is the process where cancer spreads from the original tumor to other areas of the body. These migrating cancer cells then invade nearby healthy tissue, penetrate the lymph nodes, or enter the bloodstream for distribution throughout the body.
Promising new research, however, may have found a way to halt this migration of cancer cells. Findings suggest a way to first inhibit the cells from migrating and second suggest a new way to kill these cells.
How do cancerous cells migrate?
Cancer cells can metastasize/migrate by using a set of protrusions that help them move. In new research from the Georgia Tech School of Chemistry and Biochemistry, the team managed to cut off these protrusions using a special technique.
The long, thin protrusions that enable cancer cells to move are called filopodia, which are an extension of a set of broad, sheet-like fibers called lamellipodia that are found around the edges of a cell. Lamellipodia and filopodia can be thought of as tiny legs that help healthy cells move within a tissue. Unfortunately, in cancerous cells, these “legs” are overproduced, enabling metastasis.
Nanotechnology to the rescue
In the research, the Georgia Tech team used nanotechnology to stop the cell legs from working. In nanotechnology, scientists reduce materials down to nanoscale (nano meaning billionth part of a meter). At this incredibly tiny size, materials can show new chemical and physical properties.
The researchers used what they deemed “nanorods,” which were made of gold nanoparticles, to obstruct the filopodia and lamellipodia. The nanorods had been coated with molecules called RGD peptides. These peptides made the nanorods attach to a specific kind of protein called integrin. The nanorods inhibited the integrin, blocking its functions. This had two effects: it stopped the body from overproducing lamellipodia and filopodia, and it stopped the protrusions from forming so that the cells lacked legs to migrate.
The research findings said that simply binding the nanorods to the integrin delayed the migration of the cancer cells. Also, this method avoided healthy cells, which could make this therapy less damaging for patients undergoing chemotherapy. The research says this avoidance of healthy cells is because cancerous cells overproduce specific integrins that aren’t produced in healthy cells.
The second phase of this research heated the gold nanoparticles with near-infrared laser energy. The cells did not absorb the laser light, but the gold nanorods did. When they absorbed this energy, they heated up and partially melted the cancer cells they were attached to. The research said this “mangled” the lamellipodia and filopodia, stopping its ability to help the cell move.
The goal of this research was to stop migration, not kill all the cancer cells (otherwise they couldn’t have determined if the cells had migrated or not). But the study suggests that the method of heating the nanorods with laser energy could be adjusted with the intent of killing all of the malignant cells, rather than simply inhibiting their migration.
The study said the researchers hope to be soon able to treat head, neck, breast, and skin cancers with direct, local nanorod injections combined with low-power laser energy. The laser could reach the gold nanorods at 4 to 5 centimeters down into the tissue. Deeper tumors could be treated with deeper nanorod injections.