Rutgers University scientists have shown that neurons that produce the beta-endorphin peptide (BEP) “feel good” hormone — released during exercise, a good conversation, and many other aspects of life that give humans pleasure — play a roles in regulating the stress response and immune functions to control tumor growth and progression.

To test their hypothesis about the role of BEP in controling tumor growth and progression, the Rutgers scientists took neural stem cells, transformed them into BEP neurons by treating them with particular chemicals, and then transplanted them into brains of live rats. The authors studied tumor growth in the rats that had been given carcinogens to induce prostate tumors. The authors noted that the BEP neurons boosted the immune system by increasing the activity of particular immune cell types and decreasing inflammation.

The neurons also protected the rats against prostate cancer 90 percent of the time. The researchers discovered that the “natural killer,” or NK cells that typically attack cancer cells in the body, are activated by the inserted BEP neurons. The NK cells reduced inflammation around the cancer cells, which slowed down caner cell growth and killed many of these cells.