Many current cancer treatments include chemotherapy, which can kill cancer cells wherever they end up in the body. However, chemotherapy and many other treatments have substantial side effects that are hard on patients and can themselves, cause other cancers. Scientists have long been searching for more specific ways of attacking cancer, and we’ve previously reported on some of this research. Recently, scientists discovered another approach that could kill any cancer cell, anywhere in the body and do so with potentially no side effects.
That’s the holy grail for cancer research. I hope it proves to be safe and effective.
Scientists at Northwestern University School of Medicine have discovered that all cells have a kill signal that makes the cells self-destruct if they become cancerous.
Every cell in our body contains a copy of our DNA, which holds all our genetic information. Cells use the DNA to make molecules called ribonucleic acids (RNAs). Some of these RNAs, called mRNAs, make proteins that do many of the functions in cells. There are also other RNA molecules that regulate the mRNAs. These are small RNAs called mi-RNAs, and they target specific mRNAs to destroy them or block them from making proteins. Some mi-RNAs can cause cancer by inhibiting genes that suppress tumors, or prevent cancer by inhibiting genes that can cause cancer. The mi-RNAs appear to have evolved more than 800 million years ago, when the first animals evolved.
Scientists have discovered many mi-RNAs that kill cancer cells grown in tissue culture. The mi-RNAs kill cancer cells by targeting one end of the mRNAs made from critical survival genes. Some mi-RNAs target the RNA products of many different survival genes at once, which prevents the cancer cells from becoming resistant to this method of killing. The fact that the cancer cells cannot develop resistance to the treatment is a first.
When scientists looked at the mi-RNAs that killed cancer cells, they found that a tiny string of six molecules was sufficient for killing. The scientists screened thousands of different ways to assemble this string of molecules to find which ones were best at killing cancer cells. The mi-RNA combinations that were the best at killing cancer cells looked similar to the ones made in the body.
One of the things the scientists discovered is that these potent cancer-killing six-molecule strings can increase the production of mi-RNAs that can suppress tumors and kill cancer. Amazingly, about three percent of the human genome produces mRNAs that can be processed into killer mi-RNAs.
With what scientists now know about these cancer-killing mi-RNAs, they can design potent mi-RNAs to be highly active cancer killers. Scientists need to find ways to deliver these little RNAs into the body and make sure they are not quickly degraded by enzymes known as RNAses. Though potential therapies based on these results are years away, it’s exciting to think that a universal cancer therapy might be possible someday.