The cancer switch: research breakthrough could reverse cancer growth

By: Kristina Strain, MedicalSearch Reporter
07 September, 2015

Like stepping on the brakes in a speeding car is how scientists described it: a breakthrough that could actually reverse cancer growth by targeting malignant cells.

For years, physicians have been effectively hamstrung by the limited scope of treatments available for treating cancer. If they couldn't excise the cancer via surgery, they were stuck with doing radiation or chemotherapy, both of which damage healthy cells as well as cancerous cells.

Now, they may be able to reach for a promising new option, simply injecting tumours with an elixir that can stop them from dividing, and even turn them back to "normal."

It all boils down to microRNAs, the tiny microprocessors that regulate gene expression in cells. Like little orchestra conductors, they interpret the body's signals and keep everything working in harmony — cues like when to grow and how fast are critical for maintaining the body's health. Telling cells to stop dividing is especially important.

MicroRNAs do this by producing a protein, PLEKHA7, which lyses cell bonds, but in many types of cancer, this process fails. Cells divide rampantly without microRNAs to stop them.

Amazingly, a simple injection of normal microRNAs has been shown to halt cell growth, and even return the out-of-control cells to normal form and function. The work, conducted by a team at the US-based Mayo Clinic, in Florida, was published in Nature Cell Biology in August.

The therapy, still in its development phase, has already been proven on several types of cancer. Dr. Panos Anastasiadis, of the Department of Cancer Biology, is one of the lead authors of the study.

"We have now done this in very aggressive human cell lines from breast and bladder cancer," he says.

"These cells are already missing PLEKHA7. Restoring either PLEKHA levels, or the levels of microRNAs in these cells turns tell back to a benign state. We are now working on better delivery options."

Apart from the promising new cancer treatment that may result from this work, lead author Antonis Kourtidis, PhD, says it's led to a breakthrough in understanding cell proteins.

"The study brings together two so-far unrelated research fields -- cell-to-cell adhesion and miRNA biology -- to resolve a long-standing problem about the role of adhesion proteins in cell behavior that was baffling scientists."