In vivo investigating the chemotherapeutic treatment supportive potential of bifidobacterium infantis in breast cancer treatment

While cancer is the one of the most dangerous, deadly diseases, breast cancer is the most frequently diagnosed among cancer types in women and second among causes for cancer related death in women after lung cancer. Treatments for breast cancer includes surgery, radiotherapy, chemotherapy, hormone therapy, targeted therapy and immunotherapy. Immunotherapy activates or suppress immune system to provide objective response and disease stabilization. In this thesis, the antitumor effect of Bifidobacterium infantis strain in the mouse breast cancer model as a support for chemotherapeutic treatments was investigated in vivo. Firstly in vitro experiments were carried out and the IC50 value of doxorubicin for 4T1 cell line was determined as 0.053 μg / mL. Subsequently, in in vivo experiments Balb/c mice injected with 4T1 cells (2x10^4 cells / mouse) were fed with/without gavage B.infantis milk (10^8 cfu / ml) for 14 days and treated with doxorubicin on 5th and 10th days. During the study the weights of the mice were weighed. On 15th day, mices were sacrificed and the tumor sizes were measured with caliper. The proliferation of splenocytes which collected from mice was analyzed. Co-culture was prepared with spleen cell culture and 4T1 cell culture and cytotoxic effect was observed with microscope. CD8+ T cell response was analyzed by flow cytometry. The results were determined according to the control group (K1). Splenocyte proliferation and CD8+ T cell analysis confirm these results. The best anti-tumor effect was obtained by the combined use of B.infantis and doxorubicin.