Among the different types of lung cancerthe form “small cell” (SCLC) is one of the most dangerous. But recently, a team of scientists took a step that could promise a future treatment for this disease. Researchers have found that you can stop tumor growth in mice by combining a new drug with one that is already outdated.
Lung cancer usually occurs in smokers, and the small cell form has a low survival rate. Used to treat the disease, chemotherapy is initially effective, but the cancer can quickly develop resistance to the drugs. This can lead to a recurrence or progression of the disease.
This new study was carried out by researchers from Washington University in St. Louis, Université Grenoble Alpes, and the University of Texas. Scientists have studied the resistance of SCLC cells to chemotherapy and the means to counter it.
The path followed
The scientists behind the study based on the results of a previous study which they had conducted. They had discovered that the protein called RNF113A was implicated in the ability of cancer cells to repair damage caused by alkylation. The latter is the mode of attack of most drugs used in chemotherapy.
By studying RNF113A more closely, scientists discovered that it was regulated by another protein called SMYD3. The latter is expressed in greater quantities in SCLC cells and other cancers. High levels of SMYD3 are especially associated with more aggressive cancer and greater drug resistance.
The researchers wanted to know if blocking the SMYD3 protein could improve the effectiveness of drugs. They thus grafted human SCLC cells into mice to obtain tumors in their lungs. They then treated some mice with cyclophosphamideothers with a SMYD3 inhibitorand even more with the combination of the two.
According to the results, mice given only chemotherapy saw their tumors stop growing for a period of two weeks. But then they are reappearedindicating resistance has developed.
On the other hand, in mice treated with the drug combinationthe tumors stopped growing for the duration of the experiment that corresponds to several months. Additionally, the treatment also worked on tumors taken from human patients whose cancer had already developed resistance to the drugs.
According to the information, cyclophosphamide has become an obsolete drug in recent decades. This product has indeed more severe side effects than platinum-based chemotherapy agents. The results of this new study could thus lead to a return of this drug.
Scientists hope their discovery will lead to the development of a new way to treat this aggressive form of cancer.