Anti-Depressants May Treat Deadly Small-Cell Lung Cancer

Researchers from the Stanford University School of Medicine have discovered that a grave form of cancer called SCLC (small-cell lung cancer) can be treated using two anti-depressants named imipramine and promethazine.

The study was led by Atul Butte, MD, PhD, associate professor of pediatrics and co-senior author of this study, along with Julien Sage, PhD, associate professor of pediatrics.

SCLC refers to unrestrained cell growth taking place in the lung tissues. The U.S. Food and Drug Administration have permitted the use of these two anti-depressants by humans. The researchers conducted tests on their patients using a computer technology called bioinformatics to detect massive data.

"Our collaboration with the Butte lab allowed us to move very quickly from the initial idea to very convincing results," Julien Sage said in a press release. "It was less than 20 months from the time of our first discussion to a clinical trial because the bioinformatics approach had been established and the drugs are FDA-approved. By focusing on diseases with little hope for the patient, it's easier to go forward fast."

The researchers used the anti-depressants on chemo resistant and chemo naive SCLC cells grown in a cell culture. Mouse models for human SCLC were used for the study. Researchers observed that the tricyclic anti-depressant, imipramine, did not impact the main type of lung cancer cells called non-small-cell lung adenocarcinoma, but it did slow down the cell growth of neuroendocrine tumors, Merkel cell carcinoma, an aggressive skin cancer and other cancers like pancreatic neuroendocrine cancers and pediatric cancer like neuroblastoma.

The fatal SCLC accounts for around15 percent of all lung cancers and there is no treatment for it. 

"The five-year survival for small-cell lung cancer is only 5 percent," Sage said. "There has not been a single efficient therapy developed in the last 30 years. But when we began to test these drugs in human cancer cells grown in a dish and in a mouse model, they worked, and they worked, and they worked," Sage added.

The researchers found out that these drugs worked through a class of molecule called G-protein-coupled receptors, which are present on the surface of cancer cells. The researchers are still finding out how the medicines destroy the neuroendocrine cancer cells.

"We are cutting down the decade or more and the $1 billion it can typically take to translate a laboratory finding into a successful drug treatment to about one to two years and spending about $100,000," said Atul Butte.