Philip C. Hanawalt

Philip Hanawalt is the Dr. Morris Herzstein Professor of Biology at Stanford University. His experience includes over half-a-century of research in the field of genomic maintenance since publication of his Ph.D. thesis on “Macromolecular synthesis in Escherichia coli during conditions of unbalanced growth”. He discovered the requirement for transcription to initiate the bacterial DNA replication cycle in E. coli. He co-discovered the ubiquitous process of DNA excision repair in 1963-‘64, and then discovered the sub-pathway of transcription-coupled repair (TCR) in mammalian cells, yeast and bacteria several decades later. While searching for a mutant resistant to thymineless death in E. coli he discovered RecQ, for which there are 5 homologues in humans. That discovery underscores the value of basic research in bacteria that can have profound implications for human health.

Hanawalt’s current interest focuses upon mechanisms and genetic control of TCR, and the search for gratuitous forms of TCR that may contribute to genomic instability. He studies the behavior of RNA polymerases encountering DNA lesions, guanine-rich DNA sequences and non-canonical DNA structures to learn the precise signals that initiate TCR to overcome transcription blockage. He is developing an approach, utilizing peptide nucleic acid targeted to unique expressed genes, to generate stable R-loops (RNA-DNA hybrids) in order to potentially render the act of transcription toxic for selected cells, such as those in a tumor and their metastases.