Take a moment to think about why cancer is as destructive as it is: It moves around. Some cancer cells penetrate the walls of blood or lymphatic vessels and hitch a ride through the bloodstream where they find new organs to penetrate, infiltrate and depredate. This process – metastasis – is what separates a benign tumor from a cancerous one. Stop a tumor from metastasizing, and you can beat over 90 percent of cancer-related deaths. Unfortunately, our understanding of the nuts and bolts behind metastasis is still quite limited.

A new study, just published in Nature Communications, is opening a few doors that have been up to now closed on the topic of cancer's motility. It comes from scientists at the Roswell Park Cancer Institute in Buffalo, NY, who have been studying the role of prostate cancer stem cells that promote tumor growth and metastasis.

The researchers learned that microRNAs (miRNAs) – small genetic molecules that play an essential role in regulating many aspects of cancer cell behavior – are commonly deficient or not expressed in prostate cancer stem cells.

Why not?

When the scientists dug a little deeper, they discovered that one specific miRNA molecule, miR-141, not only inhibited tumor growth but actually slowed down cancer metastasis in several pre-clinical prostate cancer models. When they factored in data from previous studies reporting the molecule’s potent tumor-suppression capability, the RPC team reckoned there was potential for miR-141 to behave as an inhibitor of prostate cancer cell invasion and metastasis. They are now suggesting that synthetic miR-141 may be developed as a “replacement” therapeutic to target prostate cancer metastasis.

“This study represents the most comprehensive investigation to date of the role of the miR-141 molecule in regulating prostate cancer stem cells and their role in metastasis,” says Dean Tang, PhD, senior author of the study. “These preliminary findings suggest that miR-141 may suppress the metastatic cascade at an early stage and that the over-expression of miR-141 in prostate cancer cells results in less metastasis. Our observations provide a rationale for developing these targeted miRNA molecules into novel anti-tumor and anti-metastasis replacement therapies.”