Cancer Drug Resistance Explained

The biomarker that aids tumors in becoming resistant to cancer-fighting drugs has been identified by investigative researchers, according to a recent study, potentially creating opportunities to increase the effectiveness of cancer-fighting medication.

It is a little known fact among healthy people that cancer-fighting drugs given to patients before and during more intensive therapies -- such as radiation therapy -- are often double-edged swords.

The drugs, which are frequently designed to inhibit cancer-promoting signaling between cells, eventually lead to tumors cells developing a resistance to those drugs, making treatment of a resurgence of cancer extremely difficult and may even lead to growth of secondary cancers.

This causes physicians to be hesitant about prescribing cancer drugs to accompany initial treatments such as chemotherapy. If the therapy is a success, and the cancer goes into remission, these drugs can help quell a relapse or stop it from even happening; but if the drugs are used in initial treatment, relapse is a far greater danger once cancer cells resurface with significant resistance to the drugs.

Other cancer cases which were temporarily cured with the medication alone races a similar threat, where relapse happens when the cancer cells fist begin to develop a resistance.

However, according to a study published in Nature Cell Biology, researchers from the University of California and the University of Texas have successfully identified a molecule known as CD61 that is found on the surface of drug-resistant tumors.

This discovery was made after the researchers analyzed tumor cells as they became resistant to receptor tyrosine kinase inhibitors -- common drugs designed to accompany standard cancer treatment options.

After identifying the molecule, which is not found in any particular prevalence on the surface of non-resistant tumors, the researchers investigated how it worked. A number of observations were made during this process, but the most important of all was that they claim to have determine the molecular pathway responsible for facilitating drug resistance.

According to the authors of the study, now knowing the pathway, the researcher hope to determine how to use this resistance-promoting process to their benefit, potentially making tumors more vulnerable to medication than they currently are.

The study was published in Nature Cell Biology on April 20.