Scientists identify lung cancer protein

Researchers from the Virginia Commonwealth University Massey Cancer Center (VCUMCC) have managed to pinpoint the protein that is heavily involved in the development of lung cancer. It is hoped that this discovery could lead to new treatments.

Around 15 per cent of all lung cancers are small cell lung cancers (SCLC), patients with this version of the disease often experience rapid growth and it can even develop resistance to chemotherapy. 

Chemotherapy is based on being able to target B-cell lymphoma 2 (Bcl-2) family proteins, which are responsible for regulating cell death. However, depending on the function, these proteins can trigger a form of cell suicide known as apoptosis or they can activate mechanisms that prevent apoptosis and promote cell survival. 

Drugs have been recently developed that block the function of pro-survival Bcl-2 family proteins. One of these drugs known as ABT-737, and its oral derivative ABT-263, have been shown to kill SCLC cells, which could increase the effectiveness of chemotherapies that target the Bcl-2 family proteins. 

However, the effectiveness of ABT-737 can differ greatly depending on what SCLC cells are being affected.

A recent study, published in Nature Publishing Group's journal Cell Death & Disease, researchers from the VCUMCC found that the Noxa protein is critical to the effectiveness of ABT-737. This is because it helps regulate the function of MCL-1, another pro-survival Bcl-2 family protein. 

During experiments with cultured SCLC cells, the team of researchers found that Noxa attaches MCL-1 to the mitochondria, which breaks down MCL-1 and makes the cancer cells more sensitive to ABT-737.

Dr Hisashi Harada, member of the Cancer Cell Signaling research program at VCUMCC, said: "Essentially, we discovered how ABT-737 works and why some small cell lung cancer cells are not as affected by it."

He added that being able to target Noxa, which breaks down MCL-1, it could potentially lead to the development of novel small cell lung cancer therapies, as well as overcoming  resistance to conventional chemotherapies.