Gertrude Case Buehring PhD

Professor Emeritus

Gertrude C. Buehring is a Professor of Virology whose goal has been to uncover a viral cause of breast cancer. She has received several honorary awards for her research including the Cornelius Hopper and Otto Sartorius awards for excellence in breast cancer research, a Fulbright Scholar Award, and a Lifetime Achievement Award from the Society for In Vitro Biology.

Dr. Buehring is a Professor of the Graduate Division associated with the Division of Infectious Diseases and Vaccinology in the School of Public Health, University of California, Berkeley. Her goal has been to uncover a viral cause of breast cancer, the most common cancer diagnosed in women worldwide, and in males 1% of the female rate.

Following the discovery in the 1970s that mouse mammary tumor virus caused breast cancer in mice and was transmitted in milk from mother to nursing pup, there was intensive research and funding to find a similar virus in humans. However, this dissipated around 1990, when no convincing viral cause had been uncovered. This was when Dr. Buehring reasoned that perhaps cattle, not humans, were the source of a potential breast cancer virus, since humans drink more cows milk than they do human milk. She turned her research attention to bovine leukemia virus (BLV), which causes widespread infection of beef and dairy cattle globally, and is commonly transmitted in milk from infected cows to nursing calves. Her primary method of identifying BLV in human breast cancer tissue sections, has been in situ PCR (polymerase chain reaction). Over the past 30 years, together with her students and/or collaborators, the requirements necessary for proving causation of an infectious disease (Bradford-Hill criteria), have been met for BLV as a cause of human breast cancer, including validation by laboratories in several other countries using their own populations of breast cancer patients. Her lab was also the first to determine a mechanism of carcinogenic action for BLV and the closely related HTLV (human T cell leukemia virus). They also determined that many humans have BLV-positive cells in their blood which could potentially be transmitted to other humans. After routes of transmission of BLV to humans are established, preventive measures to eliminate BLV-initiated breast cancers can be developed.

Her current research actively focuses on: 1) determining how BLV is transmitted to and among humans; 2) role of BLV in breast cancer of males; 3) comparing BLV DNA sequences and histologic patterns in metastatic versus primary breast cancer tissue specimens to help determine what triggers breast cancer metastasis. The ultimate goal of all her research is to prevent breast cancer from ever getting started, by eliminating or reducing the causes.
Dr. Buehring’s research has been funded by the NCI (National Cancer Institute), National Action Plan for Breast Cancer, US Department of Defense Breast Cancer Research Funds, Avon Foundation, California Breast Cancer Research Program, Susan Love Breast Cancer Foundation, and small grants from various organizations. Her publications on BLV and breast cancer are widely cited. One ranked in top 10% of citations of all publications in PLoS One in 2015. She has received several awards for her research: UCB Cornelius L. Hopper Scientific Achievement award, 1999; a Lifetime Achievement Award (Society for In Vitro Biology); a Fulbright Fellowship for collaborative breast cancer research in Costa Rica, and a finalist in the California Breast Cancer Research Program competition for research that would lead to breast cancer prevention. Editorial boards of many top journals request her review of about 2-4 manuscripts per month on research related to breast cancer and/or oncogencic viruses. In 2000, she was appointed to the Etiology Working Group of the National Action Plan on Breast Cancer.
Her service to UCB campus has been extensive, including the Committee on Research (COR), and the Chancellor’s Committee on Health and Medical Science (1980-87) where she was instrumental in developing and monitoring the basic science curriculum of the UCB-UCSF Joint Medical Program. She has served on many School of Public Health committees and was Associate Dean of Academic Affairs for 3 years and Chair of the Infectious Diseases and Vaccinology Division for 5 years. She received two teaching awards from BPH: Teaching excellence, (2016) for teaching PH162A, which she taught for 40 years, and a mentorship award based on a nomination by graduate student Gemma Niermann.

  • PhD – Genetics, UC Berkeley
  • CLS – Doctors Hospital (clinical laboratory scientist)
  • BA – Biology, Stanford University
  • Viral etiology of human breast cancer
  • Bovine leukemia virus and its possible role in causing human breast cancer
  • Primary prevention of breast cancer by eliminating bovine leukemia virus from California cattle herds, which are heavily infected.
  • Buehring GC, Kramme, PK, Schultz RD: Evidence for bovine leukemia virus in the
    mammary epithelial cells of infected cows. Laboratory Investigation 71:359-365, 1994.
  • Niermann GL, Buehring GC: Bovine leukemia virus is hormone responsive via the long
    terminal repeat. Virology 239:249-258, 1997.
  • Xiao J, Buehring GC: In vivo protein binding and functional analysis of cis-acting elements
    in the U3 region of the bovine leukemia virus long terminal repeat. Journal of Virology
    72:5994-6003, 1998.
  • Phillpott SM, Buehring GC: Defective DNA repair in cells infected with human T-cell
    leukemia/bovine leukemia virus group. Journal of the National Cancer Institute 91:933-
    942, 1999.
  • Robert-Guroff M, Buehring GC: In pursuit of a human breast cancer virus, from mouse to
    human. In Infectious Causes of Cancer: Targets for Intervention, edited by James J.
    Goedert, Humana Press Inc. Totowa, NJ 2000:475-487.
  • Choi KY, Liu RB, Buehring GC: Relative sensitivity and specificity of agar gel
    immunodiffusion, enzyme immunosorbent assay, and immunoblotting for detection of anti-
    bovine leukemia virus antibodies in cattle. Journal of Virological Methods 104: 33-39,
  • Motton D, Buehring GC: Bovine leukemia virus alters growth properties and casein
    synthesis in mammary epithelial cells. Journal of Dairy Science 86: 2826-38, 2003.
  • Buehring GC, Philpott SM, Choi KY: Humans have antibodies reactive with bovine
    leukemia virus. AIDS Research and Human Retroviruses 19: 1105-1113, 2003.
  • McGirr K, Buehring GC: tax and rex sequences of bovine leukemia virus from globally
    diverse isolates: Rex amino acid sequences more variable than tax. Journal of Veterinary
    Medicine B 52: 1-9, 2005.
  • Duncan RB, Scarratt WK, Buehring GC: Detection of bovine leukemia virus by in situ
    polymerase chain reaction in tissues from a case of sporadic bovine lymphosarcoma.
    Journal of Veterinary Diagnostic Investigation 17: 190-194, 2005.
  • McGirr KM, Buehring GC: Variation in the tax/rex region of the human T cell
    leukemia/bovine leukemia virus group: Evolutionary consequences in this overlapping
    reading frame. Virus Genes 32:229-239, 2006.
  • Zhao X, Jimenez-Sanchez C, Sentsui H, Buehring GC: Sequence polymorphisms in the
    long terminal repeat of bovine leukemia virus: Evidence for selection pressure in
    regulatory sequences. Virus Res 124: 113-124, 2007.
  • Zhao X, McGirr KM, Buehring GC: Evolutionary influences on overlapping reading frames
    in the bovine leukemia virus pXBL region. Genomics 89: 502-511, 2007.
  • Zhao X, Buehring GC: Natural genetic variations in bovine leukemia virus envelope gene:
    Possible effects of selection and escape. Virology 366:150-165, 2007.
  • Lee L, Scarratt WK, Buehring GC, Saunders GK: Bovine leukemia virus infection in a
    juvenile alpaca with multicentric lymphoma. Canadian Veterinary Journal 53:283-286,
  • Buehring GC, Shen HM, Jensen HM, Choi KY, Sun D, Nuovo, G: Bovine leukemia virus
    DNA in human breast tissue. Emerging Infectious Diseases 20: 772-782, 2014.
  • Buehring GC, Shen HM, Jensen HM, Jin DL, Hudes M, Block, G: Exposure to bovine
    leukemia virus is associated with breast cancer: A case-control study (PLoS ONE, DOI: 10.137/journal.pone.0134304)
  • Buehring GC, Shen HM, Schwartz DA, Lawson J, Bovine leukemia virus linked to breast
    cancer in Australian women and identified before breast cancer development. PLoS One. 2017
    Jun 22;12(6):e0179367. doi:10.1371/journal.pone.0179367.
  • Kimberly Baltzell, Hua Min Shen, Savitri Krishnamurty, Jennette Sison, Gerard Nuovo,
    Gertrude C. Buehring, PhD. Bovine leukemia virus linked to breast cancer but not co-infection
    with human papillomavirus: Case-control study of Texas women, Cancer 124:1342-9, 2018.
  • Lendez PA, Cuesta LM, Farias, MVN, Shen HM, Guillermina LD, Buehring GC, Ceriani,
    MC. Bovine leukemia virus presence in breast tissue of Argentinian Females and Its Association
    with Cell Proliferation and Prognosis Markers. Multidisciplinary Cancer Investigations 2:4,
    October 2018, DOI: 30699/acadpub.mci 4:16
  • Buehring GC, DeLaney A, Shen HM, Chu DL, Razavian N, Schwartz DA, Demkovich ZR,
    Bates MN. Bovine leukemia virus discovered in human blood. BMC Infectious Diseases19:297,
  • Buehring GC, Sans, H. Breast cancer gone viral? Review of bovine leukemia virus role in
    causation, and related opportunities for cancer prevention. International Journal of
    Environmental Research and Public Health, 2020, 17,209; doi:10.3390/ijerph17010209
  • PH 298
  • PH 299
  • URAP mentoring