Controlling Cancer Growth

Current therapies for head and neck cancer such as surgery, radiation therapy, and chemotherapy control cancer at the cost of normal tissues, sometimes damaging them permanently. That’s why scientists are searching for drugs that target and kill cancer cells without harming healthy tissues. Dr. Silvio Gut­kind and his team at the National Institute of Dental and Craniofacial Research (NIDCR) reported in Mole­cular Oncology that p38 kinase is active in head and neck cancer cells, and blocking p38 may help prevent cancers from growing. Al­though p38 is known to play a role in breast and bladder cancers, these results may be the first to show that p38 plays a highly active role in head and neck cancers.

After analyzing tissue samples of hundreds of head and neck cancer patients, the NIDCR team found that the most malignant tissue samples had the highest activity of p38, and the least malignant samples had the lowest p38 activity. The normal oral tissue used as a control had no p38 activity. When the team used a gene knockdown technique to turn off p38 activity in human oral cancer cells and transplanted those cells into lab mice, the oral cancers without p38 activity were smaller than those with p38 activity. In addition, turning off p38 activity diminished the growth of new blood vessels, which cancers rely on for growth and the ability to spread to other parts of the body.

The next phase of the study was to test SB203580, a drug that is known to block p38 activity. As expected, SB203580 reduced the growth of head and neck cancer cells in the lab, and when SB203580 was used to treat human head and neck cancers that had been transplanted into lab mice, SB203580 made the cancers smaller. The next step is to test a new generation of drugs that inhibit p38.

(Source: NIDCR, January 31, 2014)