University Professor Jean C. Shih has published her latest research findings, the identification of a signaling pathway and its impact on cell growth and death, in the July 7 issue of the Proceedings of the National Academy of Sciences.

The discovery, which builds on Shih’s pioneering molecular research on the MAO enzymes spanning the last three decades, demonstrates a new cellular signaling pathway, specifically involving the MAO A enzyme and R1 transcription factor.

This new enzyme function points researchers to future areas of study that eventually may impact therapies for cancer and neurodegenerative diseases.

“The involvement of MAO A in cell death suggests that this enzyme may have a larger role in neurodegenerative diseases and psychiatric disorders,” said Shih, professor of molecular pharmacology and holder of the Boyd P. and Elsie D. Welin Professorship in the USC School of Pharmacy. “Previously, we thought the enzyme’s only effect had to do with the oxidizing of the neurotransmitters. This finding opens a new direction for research in neurodegenerative diseases.”

The study also elucidates the enzyme’s action in cell growth, possibly impacting cancer therapies in the future.

“Our work provides another building block in understanding the complexities of the cell, including proliferation and death,” said Kevin Chen, co-investigator and research associate professor of molecular pharmacology and toxicology in the School of Pharmacy. “As we learn more about cell behavior, we come closer to better understanding many diseases and to discovering therapeutic regimens to fight them.”

Xiao-Ming Ou, research assistant professor of molecular pharmacology and toxicology in the School of Pharmacy, is the first author on the study.