Investigation Of The Effects Of Krill Oil On Triple-Negative Breast Cancer Orthotic Tumor In The Cd-1 Nude Mouse Model

This study aimed to comprehensively evaluate the multidimensional effects of krill oil on primary tumor biology, proliferative activity, the tumor microenvironment, and lung micrometastasis in a mouse model of triple-negative breast cancer (TNBC). An orthotopic breast cancer model was established in female CD-1 nude mice using the MDA-MB-231 human TNBC cell line. Krill oil was administered to the treatment group via oral gavage 24 hours after the injection of tumor cells into the breast fat tissue. Lung micrometastases were evaluated using micro-positron emission tomography (micro-PET) imaging. Tumor tissues were analyzed for necrosis rate using hematoxylin and eosin staining and for proliferative activity using Ki-67 immunohistochemical staining. The Ki-67 index was significantly lower in the krill oil treated group compared to the control group (p<0.001). Histopathological evaluation revealed a significant increase in tumor necrosis rate in the treatment group compared to controls (p=0.002). Regarding metastatic dissemination, micro-PET assessments demonstrated a significantly lower lung micrometastasis density in the krill oil group than in the control group (p=0.022). Correlation analyses revealed a strong negative correlation between the Ki-67 index and the tumor necrosis rate (p=0.006), as well as between the Ki-67 index and tumor volume (p=0.002). Conversely, a significant positive correlation was identified between the Ki-67 index and lung micrometastasis density (p=0.019). These findings demonstrate that krill oil exerts prominent biological effects in an orthotopic model of TNBC by suppressing proliferative activity, modulating the tumor microenvironment toward necrosis and stromal remodeling, and mitigating the metastatic burden.