Discovering Methotrexate's Role in Lung Cancer Treatment

MicroRNAs, or miRNAs, are tiny molecules that can greatly influence how cancer cells grow. Out of all these miRNAs, miR-20b is particularly interesting because it's often out of balance in lung cancer. Scientists used a special computer program to search for small molecules that could tame miR-20b. Out of many options, Methotrexate (MTX), a known drug, stood out. MTX seemed to work best in lung cancer cells that still had a functional p53 protein, a key player in cell growth control. In these cells, MTX blocked a process called Dicer processing, which is essential for miR-20b to do its job. This led to less miR-20b activity and slowed down the growth, survival, and spread of the cancer cells. MTX also boosted the levels of certain proteins that miR-20b usually keeps in check, like PTEN, STAT3, and HIF1α. When tested in a mouse model, MTX slowed tumor growth without causing any major side effects. This finding is exciting because it shows that MTX, an already approved drug, might have a new job in fighting lung cancer by controlling miR-20b. This could pave the way for new treatment strategies targeting miR-20b in lung cancer.