ILS scientist identifies enzyme causing breast cancer in nicotine-consuming women

By A K SAHOO

Bhubaneswar , Dec. 15: Institute of Life Sciences is once again in the news for discovery of a “culprit” enzyme that causes metastasis in smoking group people, mostly women, suffering from breast cancer.

Metastasis is development of secondary malignant growths at a distance from a primary site of cancer.

The culprit enzyme – Enhancer of Zeste Homolog 2 (EZH2) – is mainly involved in suppression of gene expression by promoting a “chemical event” known as “methylation.”

According to Dr Mishra, who is the head of the molecular oncology lab in the department of cancer biology at ILS, pregnant women should stay away from smoking as it may lead to breast cancer and may also result in metastasis which is more alarming than simple malignant tumor.

“We have identified the culprit enzyme which is associated with the nicotine related breast cancer in smoking population. The inhibitor that enzyme may be promoted to work as a drug to checkmate the nicotine associated breast cancer. The candidate target is EZH2,” said Dr Mishra.

Nicotine associated breast cancer in smokers is mediated through high level of EZH2 expression which can be reversed by methyltranferase inhibitor DZNepA.

Breast cancer is the second leading cause of cancer related deaths in women worldwide.

“Studies show that female smoking in India is growing at a faster rate than smoking by males. In this context, using mice model, we have experimentally proven that nicotine has a significant role in breast cancer. In our investigation, we found that nicotine can regulate one of the cancer promoting genes (oncogene) named EZH2. The cancer-promoting role of nicotine can be controlled by targeting the therapeutics that has potential to suppress the nicotine-aggravated genes,” Dr Mishra claimed. Another important thing which takes the standard of the paper to the next height is Mishra and his team have also shown that EZH2 enzyme is high in nicotine related breast cancer in comparison to nicotine null breast cancer in human sample.

He added, “In our study, we blocked the EZH2 function, and showed reduced breast tumor growth in the mice model. The take home message from our study is that we should be aware that these preventable environmental factors might play significant role in breast cancer development. Therefore, as said, prevention is better than cure; – prevent smoking, and prevent breast cancer.”

The finding of the ILS research team has been accepted for publication in a highly prestigious Journal “Cell Death and Diseases” which has a high impact factor and belongs to Nature group of Journal.

Dr Mishra’s group had earlier this month “conclusively” proved that cancer cells migration and invasion can be restricted as well as induced apoptosis (programmed cell death) can also be controlled by Artemisinin in estrogen receptor positive (ER-positive) breast cancer cells.