Experimental Drug Treatment Stops A Deadly Form of Lung Cancer in Mice

Scientists have been able to stop the progress of small cell lung cancer through an experimental combination of two drugs. Human trials are planned now that the promising results are behind them.

Since the 1980s, the drug cyclophosphamide has not been used to treat small cell lung cancer.

The cancer will develop resistance to the treatment if cyclophosphamide is used.

The team behind the new experiments has been able to identify how small cell lung cancer cells resist the effects of cyclophosphamide.

They've developed a technique that blocks the repair process of the cancer cells.

There is a problem with these tumors coming back after treatment. Nima Mosammaparast is a Pathologist and Immunologylogist at Washington University in St Louis.

The tumors are very resistant to everything.

The new findings build on previous research from the same team that identified the RNF113A as being involved in cancer cell repair, specifically, in the repair of a type of DNA damage known as alkylation damage.

The research showed that RNF113A is regulated by SMYD3 and that it is found in higher levels in lung cancer. There is a correlation between elevated levels and increased resistance to alkylating chemotherapy drugs.

Lung tissue has low levels of SMYD3.

The researchers were able to target SMYD3 in mice with human lung tumors because of their knowledge.

When cyclophosphamide and an SMYD3 inhibition were combined, the cancer stopped growing completely.

After other treatments had failed, this tumor suppression lasted for a month.

Mosammaparast says that the study shows that we can combine a new target with an old drug to make the treatment more effective.

Because this has only been tested in mice, scientists want to conduct further experiments to see if they can reduce the level of cyclophosphamide involved to limit the toxic side effects.

Even if they are less harmful to the body, the drugs that replaced cyclophosphamide aren't any better at fighting small cell lung cancer. Two to six months of life can be added by current treatments.

The researchers are trying to organize phase 1 clinical trials. The research shows that it can work on cancer that have already become resistant to some treatments.

Mosammaparast says that one of the challenges will be convincing doctors to use an old drug. The strategy may work if current therapies fail.

The research was published in a journal.