Date of Submission


Document Type


Degree Name

Master of Science in Cellular and Molecular Biology


Biology and Environmental Sciences


Dr. Eva Sapi

Committee Member

Dr. Alireza G. Senejani

Committee Member

Dr. Kate E. Miller


Breast cancer, Borrelial DNA, Tumor development, Mammary tissues, Spirochetal organism, Matrigel Invasion and Wound Healing Assays


Borrelia burgdorferi, Breast Neoplasms, Immunohistochemistry, Polymerase chain reaction, Epithelial cells


Borrelia burgdorferi, Breast--Cancer--Research, Immunohistochemistry, Polymerase chain reaction, Epithelial cells


Borrelia burgdorferi, the causative agents of Lyme Disease, is known to able to disseminate and colonize various organs and tissues of its hosts, which is very crucial for its pathogenicity and survival. Recent studies have shown the presence of Borrelial DNA in various kinds of breast cancer tissues which raises the question about whether B. burgdorferi could play a role in tumor development. The first objective of the study was to confirm the presence of B. burgdorferi DNA and investigate the potential presence of antigen in normal and breast cancer tissues using immunohistochemistry (IHC) and PCR technology. IHC analysis showed approximately 32% of the breast cancer tissues were positive for B. burgdorferi s.l. and approximately 12% were positive for B. burgdorferi s.s., but none of the normal breast tissues were found to be positive for Borrelial antigen. PCR technology further confirmed the presence of Borrelial DNA in breast cancer, but not in normal mammary tissues. Confocal microscopy images confirmed individual spirochetal organism of all the positive cancer tissues as well as biofilm forms in invasive ductal breast carcinoma samples. The second part of the study was designed to assess the effect of Borrelial infection in mammary epithelial cells. The immunofluorescence and confocal microscopy results showed that Borrelia is capable of invading normal epithelial (HC11) and a breast carcinoma cell line (MDA-MB-231) within 24 hours, however, the infection rate for the breast carcinoma cells line was significantly higher. While the infection of epithelial cells with B. burgdorferi did not cause any changes in cell proliferation rates, it showed significant effect on the invasion and migration capacity for both normal and breast cancer cells determined by Matrigel Invasion and Wound Healing Assays. For HC11 cells, there was a 16-fold increased rate of invasion and 3-fold increased rate of migration, while the breast cancer cells, MDA-MB-231, showed a 3-fold increase in invasion and 2-fold increase in migration capacity. In summary, our results suggest that 7 spirochetal organism could play important role in the development of cancer in breast tissues. Further studies, however, are necessary to confirm the causal relationship of borrelial infection and cancer development.

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