Skip to Main Content

Joann Sweasy, PhD

Ensign Professor Emeritus of Therapeutic Radiology

Contact Information

Joann Sweasy, PhD



I am an expert in the genetics, cell biology, mutagenesis and biochemistry of DNA repair and cancer and have been funded continuously by the NIH since 1994. A major focus of my laboratory is to understand how single nucleotide polymorphisms in DNA repair genes, including genes that function in homology directed repair (HDR), nonhomologous end-joining (NHEJ) and base excision repair (BER) in the germline and somatic tissues impact cancer risk and treatment. We have recently found that RAD51, DNA glycosylase, and POLB germline and somatic tumor variants exhibit functional phenotypes that lead to cellular transformation, genomic instability, and sensitivity or resistance to chemotherapies and ionizing radiation. We have also developed methods to monitor DNA damage in tissue including the presence of single and double strand breaks that lead to PARP activation and trapping. In addition to this, I have focused on determining the roles of DNA repair in a vertebrate organism and have concentrated my studies on mouse models of DNA repair variants. Using these models I have revealed critical roles for DNA repair in preventing the autoimmune disease of lupus. As Associate Director for Basic Research at the Yale Comprehensive Cancer Center, I oversee several pilot and internal grant competitions, am the Principal Investigator of the American Cancer Society Institutional Research Grant, and am currently leading the development of a Translational Research Core which is designed to link patient health records to biospecimens, genomics data, and a living tumor registry.

Education & Training

  • Postdoctoral Research Fellow
    University of Washington, Seattle, WA (1993)
  • PhD
    Rutgers University (1989)
  • Graduate Research Fellow
    Rutgers University,Piscataway, NJ (1989)
  • Senior Staff Microbiologist
    Merck and Company, Rahway, NJ (1989)
  • BA
    Beaver College, Biology and Chemistry (1980)
  • Undergraduate Research Assistant,
    Beaver College, Glenside, PA (1980)
  • Postdoctoral Fellow
    University of Washington, Seattle, WA

Honors & Recognition

Argall and Anna Hull Award
American Cancer Society Junior Faculty Research Award
Donaghue Investigator Award

Departments & Organizations