Unveiling a new factor that helps breast cancer cells to tolerate drugs

from biotechin.asia by Mohamad Moustafa Ali

Breast cancer is one of the most divergent and heterogeneous genetic disorders that affects hundreds of thousands of women worldwide every year. Scientists have systematically classified breast cancer tumors into different types, whereas each type possesses different characteristic features. Among these different types, endocrine receptor-positive (ER+) is the most common one.

The ER+ breast tumors depend mainly on the estrogen hormone to promote cellular division and maintain tumors size. The most commonly used treatment for ER+ tumors relies on the use of chemical components that block estrogen receptors in cancer cells. Although the available hormone-based drugs helped a lot of women to overcome the disease, a significant portion of the patients suffer from the recurrence and relapse of the disease after several years of successful treatment. For many years, scientists failed to explain how ER+ cells can adapt and tolerate the drugs, especially in post-menopausal stage.

A Japanese group, led by Professor Mitsuyoshi Nakao and Professor Noriko Saitoh at Kumamoto University, has recently published a research article in Nature Communications journal that helps to explain the adaptation process.

The research group was able to identify a new long non-coding RNA called u-Eleanors that allows cancer cells to survive harsh environment. Basically, long non-coding RNAs are ribonucleic acids which are longer than 200 base pair in length and can’t produce any proteins, unlike protein coding RNAs. For decades, scientists didn’t pay attention to long non-coding RNAs, however, recently, a lot of recent research papers are assigning many important functions to that special class of RNAs.

The Japanese group has proven that u-Eleanor RNA is produced in higher amount to enhance the function of the well-known cancer associated estrogen receptor gene (ESR1) and allow it to gain resistance against hormone-based drugs. The study concluded that eliminating the harmful u-Eleanors RNA from ER+ tumors may represent a new perspective for novel therapeutics and drugs development.

• Tomita S, Abdalla MO, Fujiwara S, Matsumori H, Maehara K, Ohkawa Y, Iwase H, Saitoh N, Nakao M. (2015) A cluster of noncoding RNAs activates the ESR1 locus during breast cancer adaptation. Nat Commun 6:6966. [article]

Source – biotechin.asia