Ann R. Kennedy

faculty photo
Richard Chamberlain Professor of Research Oncology
Department: Radiation Oncology
Graduate Group Affiliations

Contact information
195 John Morgan Building
3620 Hamilton Walk
Philadelphia, PA 19104-6072
Office: 215 898-0079
Fax: 215 898-0090
A.B. (Biology)
Vassar College , 1969.
M.S. (Radiation Biology)
Harvard University , 1971.
D.Sc. (Radiation Biology)
Harvard University, 1973.
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Description of Research Expertise

Cancer, proteases, protease inhibitors, cancer prevention, oncogenes, gene expression, radiation acute effects, space radiation.

Biological effects of radiation, with emphasis on carcinogenesis, cancer prevention and acute radiation effects.

Research in the Kennedy laboratory has primarily involved studies on the mechanism(s) involved in radiation induced malignant transformation and its modification by various chemical agents in both in vitro and in vivo experimental systems. Cancer prevention continues to be a major focus of research, with the primary cancer chemopreventive agents evaluated being protease inhibitors as well as other classes of agents known to modify free radical reactions. The studies on free radical modifying agents focused on the ability of agents to affect radiation induced oxidative stress, and the ability of protease inhibitors to act as cancer preventive agents focused on the ability of dietary protease inhibitors to inhibit the activity of a protease known as chymotrypsin. Early studies identified the soybean-derived protease inhibitor known as the Bowman-Birk inhibitor (BBI) to be a particularly effective cancer preventive agent. Studies on the mechanism of action of the protease inhibitor suppression of carcinogenesis have focused on the effects of these agents on the expression of specific oncogenes and proteases thought to be involved in the conversion of a cell to the malignant state. Human trials utilizing BBI as a cancer chemopreventive agent started in 1992 and some have been completed recently. Some of the current laboratory work involves studies on the effects of BBI on surrogate endpoint biomarkers (SEBs) of carcinogenesis in tissues of experimental animals treated with BBI.

Much of the most recent work of the Kennedy laboratory has been focused on studies related to the acute radiation risks for astronauts exposed to solar particle event (SPE) radiation. SPEs can involve relatively high doses of radiation that can cause symptoms of the acute radiation syndrome (ARS). The aims of these studies are to determine whether there are adverse acute biological effects like those of the ARS, which are likely to occur in astronauts exposed to the types of radiation, at the appropriate energies, doses and dose-rates, present during an SPE. Kennedy lab. members have performed mechanistic studies on SPE radiation induced adverse effects and their mitigation or prevention by potential countermeasures, with emphasis on hematologic and immune system alterations (with many experiments performed both with and without simulated hypogravity conditions). Some specific examples include SPE radiation effects on: 1) lymphocyte and neutrophil activation and function, and 2) blood coagulation parameters. Among the most notable findings in this area of research is that both space radiations, as well as gamma or x-rays, produce disseminated intravascular coagulation (DIC) in experimental animals at relatively low doses of radiation. Our results indicate that radiation activates the coagulation cascade, which results in radiation induced coagulopathy (RIC), with bleeding/hemorrhage/microvascular thrombosis and organ damage, and the ultimate development of DIC, at relatively low-moderate doses of radiation. Current experiments are aimed at the development of novel agents that may prevent or mitigate the development and/or progression of RIC/DIC in experimental systems.

1. I have made extensive contributions to the field of cancer research, with particular focus on radiation carcinogenesis in both in vivo and in vitro systems. In the early stages of my career, I started studying in vivo carcinogenesis induced by high linear energy transfer (LET) radiation; these in vivo carcinogenesis studies have continued through all phases of her career up until the present time with studies on the prevention of carcinogenesis in many different animal model systems. Among my earliest research investigations were studies on alpha radiation induced lung cancer from 210Po, which is contained in cigarettes and cigarette-smokers’ lungs. Lung cancers were induced in hamsters that received doses of alpha radiation from 210Po that were within the range of doses received by the bronchial epithelium of cigarette smokers. These findings suggested that the alpha radiation resulting from the 210Po present in cigarette smoke could be a significant causative factor in lung cancer (a). Also, early in my career, I began to perform studies on radiation induced malignant transformation in vitro, with an early publication that indicated that fluorescent light was capable of causing the malignant transformation of cells (b). This finding had some practical applications. Given the results described in our publication, I understand that Hyclone, a major company that provides products for biomedical research, changed the types of bottles for their products that could be affected by fluorescent light. Two of my papers are widely considered seminar papers; specifically, these are publications (c) and (d) below. These papers served as a basis for defining the kinetics of radiation induced malignant transformation in vitro. The 1980 PNAS paper was reprinted in “Readings in Mammalian Cell Culture” (editor, Robert Pollack, pp. 235-239, Cold Spring Harbor Laboratory, 1981), which is a collection of seminar papers in cell biology. The major findings of these papers was that the first event in the induction of radiation induced malignant transformation was a high frequency event, assumed to be an epigenetic event, and that a later event in the transformation process occurred during division of an irradiated population of cells at a frequency expected for a mutational event. It was believed that the secondary or later event was the alteration that led directly to the malignant state. The transformation frequency could be greatly altered, with some agents, like tumor promoters, raising the frequency, and other agents, like protease inhibitors and antioxidants, reducing the frequency. My studies were the first to show that agents could modify radiation induced transformation in vitro. I view this concept as the foundation for the rest of my career. At the time I entered the field of radiation biology, it was believed that radiation had the ability to start a process that was destined to result in cancer. My work has focused on a new concept – that radiation carcinogenesis is not an inevitable progression and it can be prevented. It is now believed by most investigators in this field of research that radiation carcinogenesis is a potentially preventable disease.
(a) Little, J.B., Kennedy, A.R. & McGandy, R.B. (1975). Lung cancer induced in hamsters by low doses of alpha radiation from polonium-210. Science, 188(4189), 737-38.
(b) Kennedy, A.R., Ritter, M.A. & Little, J.B. (1980) Fluorescent light induces malignant transformation in mouse-embryo derived cells. Science 207(4436), 1209-11.
(c) Kennedy, A.R., Fox, M., Murphy, G. & Little, J.B. (1980) Relationship between x-ray exposure and malignant transformation in C3H10T1/2 cells. Proc Natl Acad Sci USA 77(12), 7262-66.
(d) Kennedy, A.R., Cairns, J. & Little, J.B. (1984) Timing of the steps in transformation of C3H10T1/2 cells by X-irradiation. Nature 307(5946), 85-86, 1984.

2. Although many different classes of cancer chemopreventive agents were evaluated for the ability to suppress radiation induced transformation in vitro in my laboratory (e.g., hormones (a)), the class of compounds that were most effective as cancer chemopreventive agents were protease inhibitors. My original publication indicating that protease inhibitors could suppress radiation induced transformation in vitro was in 1978 (b). Subsequent publications on the extraordinary ability of protease inhibitors to suppress radiation transformation in vitro (c) and carcinogenesis in animals (e.g., d) showed that these agents could prevent radiation and chemically induced carcinogenesis in vivo and in vitro without toxic effects.
(a) Kennedy, A.R. & Weichselbaum, R.R. (1981) Effects of dexamethasone and cortisone with x-irradiation on the malignant transformation of C3H10T1/2 cells. Nature 294(5836), 97-98.
(b) Kennedy, A.R. & Little, J.B. (1978) Protease inhibitors suppress radiation induced malignant transformation in vitro. Nature 276(5690), 825-26.
(c) Yavelow, J., Collins, M., Birk, Y., Troll, W. & Kennedy, A.R. (1985) Nanomolar concentrations of Bowman-Birk soybean protease inhibitor suppress X-ray induced transformation in vitro. Proc Natl Acad Sci USA 82(16), 5395-5399.
(d) Messadi, P.V., Billings, P., Shklar, G. and Kennedy, A.R. (1986) Inhibition of oral carcinogenesis by a protease inhibitor. J. Natl. Cancer Inst. 76(3), 447-452.

3. As part of our numerous studies on the protease inhibitor suppression of carcinogenesis, numerous studies were performed to elucidate the mechanism of action of these agents; references a-c below represent examples of these types of studies. Our studies on the cancer chemopreventive ability of protease inhibitors led to an invited article in Pharmacology and Therapeutics (d), which was peer-reviewed by the journal.
(a) Kennedy, A.R., Radner, B. and Nagasawa, H. (1984) Protease inhibitors reduce the frequency of spontaneous chromosome abnormalities in cells from patients with Bloom syndrome. Proc Natl Acad Sci USA 81(6), 1827-1830.
(b) Billings, P.C., Carew, J.A., Keller-McGandy, C.E., Goldberg, A.L. & Kennedy, A.R. (1987) A serine protease activity in C3H/10T1/2 cells that is inhibited by anticarcinogenic protease inhibitors. Proc Natl Acad Sci USA 84(14), 4801-4805.
(c) Wan, X.S., Meyskens, F.L., Jr., Armstrong, W.B. & Kennedy, A.R. (1999) Relationship between a protease activity and neu oncogene expression in patients with oral leukoplakia treated with the Bowman-Birk inhibitor. Cancer Epidemiology, Biomarkers and Prevention 8(7), 601-608.
(d) Kennedy, A.R. Chemopreventive agents: protease inhibitors. (1998) Pharmacology & Therapeutics 78(3), 167-209.

4. The studies cited above formed the basis for my studies of the soybean-derived protease inhibitor, known as the Bowman-Birk Inhibitor (BBI), in human populations. This phase of my career began with my application to the Food and Drug Administration (FDA) for approval to use BBI in human trials. BBI achieved Investigational New Drug Status with the FDA in 1992, and human trials began at that time. I have held the INDs from the FDA for 6 different areas of research involving human trials, which include cancer prevention (in patients with oral leukoplakia, a pre-malignant condition), prevention and treatment of benign prostatic hyperplasia, prostate cancer treatment, prevention and treatment of esophagitis in patients with lung cancer, and treatment of gingivitis and ulcerative colitis. It is expected that trials of BBI in patients with muscular dystrophy and multiple sclerosis will begin at some point in the future. Some of our human trial work is described in the publications below.
(a) Manzone, H., Billings, P.C., Cummings, W.N., Feldman, R., Clark, L., Odell, C.S., Horan, A., Atiba, J.O., Meyskens, F.L., Jr., & Kennedy, A.R. (1995) Levels of proteolytic activities as intermediate marker endpoints in oral carcinogenesis. Cancer Epidemiology, Biomarkers and Prevention 4(5), 521-527.
(b) Armstrong, W.B., Kennedy, A.R., Wan, X.S., Taylor, T.H., Nguyen, Q.A., Jensen, J., Thompson, W., Lagerberg, W. & Meyskens, F.L., Jr. (2000) Clinical modulation of oral leukoplakia and protease activity by Bowman-Birk Inhibitor Concentrate in a Phase IIa Chemoprevention Trial. Clinical Cancer Research 6 (12), 4684-91.
(c) Malkowicz, S.B., McKenna, W.G., Vaughn, D.J., Wan, X.S., Propert, K.J., Rockwell, K., Marks, S.H.F., Wein, A.J. & Kennedy, A.R. (2001) Effects of Bowman-Birk Inhibitor Concentrate in patients with benign prostatic hyperplasia. The Prostate 48(1), 16-28.
(d) Lichtenstein, G.R., Deren, J.J., Katz, S., Lewis, J.D., Kennedy, A.R. & Ware, J.H. Bowman-Birk Inhibitor Concentrate (BBIC). (2008) A novel therapeutic agent for patients with active ulcerative colitis. Digestive Diseases and Sciences 53(1), 175-180.

5. Many of my most recent research investigations have focused on the discovery of the effects of space radiation and countermeasures for those effects. The major types of space radiation evaluated in these studies were galactic cosmic rays and solar particle event (SPE) radiation. Galactic cosmic radiation includes high energy and high atomic number particles known as HZE particles; HZE particles are high LET radiation. SPE radiation is primarily composed of protons. As a major aim of the studies performed as part of the recently completed NSBRI-funded Center of Acute Radiation Research (CARR) grant was to determine relative biological effectiveness (RBE) values for space radiations to produce different types of adverse biological effects, the CARR studies were also performed with reference radiations (i.e., gamma or x-rays, or electrons). This was a large project, in which I headed a multidisciplinary team of basic researchers, with expertise in radiobiology, physics, physiology, immunology, hematology and behavioral research, and clinicians with expertise in several areas, including radiation oncology, dermatology, hematology and infectious disease. The results of the studies performed as part of the CARR grant have been described in an invited review article (a) (this article was peer-reviewed by the journal). From my perspective, among the most important findings of the CARR grant work was that both space radiations (e.g., protons), as well as gamma or x-rays, produced disseminated intravascular coagulation (DIC) in experimental animals (b, c) at relatively low doses of radiation. It has been observed that DIC develops through sequential stages in experimental animal model systems (a, b). It is believed that radiation induced DIC begins as a consumptive coagulopathy shortly after subjects are exposed to relatively low doses of radiation (e.g., d). Our results indicate that radiation activates the coagulation cascade and induces changes in hemostasis, which results in radiation induced coagulopathy (RIC). It is hypothesized that RIC induces bleeding/hemorrhage/microvascular thrombosis and organ damage at relatively low-moderate doses of radiation. It is expected that similar changes occur in irradiated people (a-c). The results from our experiments could have great significance for the consequences of the acute radiation syndrome in humans, and it is possible that our results will lead to changes in the manner in which the biologic effects of radiation exposure are diagnosed, treated and prevented in people exposed to radiation through occupational accidents, radiation terrorism or other catastrophic events.
(a) Kennedy, A.R. (2014) Biological effects of space radiation and development of effective countermeasures. Life Sciences in Space Research 1(1), 10-43.
(b) Krigsfeld, G.S., Savage, A.R., Billings, P.C., Lin, L., & Kennedy, A.R. (2014) Evidence for radiation induced disseminated intravascular coagulation as a major cause of radiation induced death in ferrets. Int J Radiat Oncol Biol Phys 88(4), 940-946.
(c) Krigsfeld, G.S., Shah, J.B., Sanzari, J.K., Lin, L. & Kennedy, A.R. (2014) Evidence of disseminated intravascular coagulation in a porcine model following radiation exposure. Life Sciences in Space Research 3: 1-9.
(d) Krigsfeld, G.S., Sanzari, J.K. & Kennedy, A.R. (2012) The effects of proton radiation on the prothrombin and partial thromboplastin times of irradiated ferrets. Int J Radiation Biology 88(4), 327-334.

Selected Publications

Sanzari JK, Krigsfeld GS, Shuman AL, Diener AK, Lin L, Mai W, Kennedy AR : Effects of granulocyte colony stimulating factor, Neulasta, in minipigs exposed to total body proton irradiation. Life Sci Space Res. 5: 13-20, Apr 1 2015.

Li M, Holmes V, Ni H, Sanzari JK, Romero-Weaver AL, Lin L, Carabe-Fernandez A, Diffenderfer ES, Kennedy AR, Weissman D : Broad-spectrum antibiotic or G-CSF as potential countermeasures for impaired control of bacterial infection associated with an SPE exposure during spaceflight. PLoS One. 10(3): e0120126, Mar 20 2015.

Billings PC, Sanzari JK, Kennedy AR, Cengel KA, Seykora JT: Comparative analysis of colorimetric staining in skin using open-source software. Exp Dermatol 24(2): 157-9, Feb 2015.

Sanzari JK, Wan XS, Muehlmatt A, Lin L, Kennedy AR : Comparison of changes over time in leukocyte counts in Yucatan minipigs irradiated with simulated solar particle event-like radiation. Life Sci Space Res. 4: 11-16, Jan 1 2015.

Sanzari JK, Billings PC, Wilson JM, Diffenderfer ES, Arce-Esquivel AA, Thorne PK, Laughlin MH, Kennedy AR.: Effect of electron radiation on vasomotor function of the left anterior descending coronary arter. Life Sci Space Res. 4: 6-10, Jan 2015.

Krigsfeld GS, Shah JB, Sanzari JK, Lin L, Kennedy AR: Evidence of disseminated intravascular coagulation in a porcine model following radiation exposure. Life Sci Space Res. 3: 1-9, Oct 1 2014.

Ni J, Romero-Weaver AL, Kennedy AR: Potential beneficial effects of Si-Wu-Tang on white blood cell numbers and the gastrointestinal tract of gamma-ray irradiated mice. Int J Biomed Sci. 10(3): 182-90, Sep 2014.

Billings PC, Romero-Weaver A, Kennedy AR: Effect of gender on the radiation sensitivity of murine blood cells. Gravit Space Res. 2(1): 25-31, Aug 1 2014.

Romero-Weaver AL, Lin L, Carabe-Fernandez A, Kennedy AR: Effects of Solar Particle Event-Like Proton Radiation and/or Simulated Microgravity on Circulating Mouse Blood Cells. Gravit Space Res. 2(1): 42-53, Aug 2014.

Romero-Weaver AL, Ni J, Lin L, Kennedy AR: Orally administered fructose increases the numbers of peripheral lymphocytes reduced by exposure of mice to gamma or SPE-like proton radiation. Life Sciences in Space Res. 2: 80-85, July 2014.

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Last updated: 07/24/2015
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