Prophylactic Autologous Cancer Cells Immunization Inhibits Triple Negative Breast Tumors’ Growth and Metastasis in 4T1 Tumor-Bearing BALB/c Mice

Abstract

Triple negative breast cancer (TNBC), a type of breast cancer, is still incurable and 4T1 tumor is an equal experimental model of TNBC which is highly metastatic and invasive. In the present study, we assessed the prophylactic cancer vaccine effects on survival and metastasis in 4T1 tumor bearing mice. Female BALB/c mice were divided in three groups and subcutaneously (s.c) injected with PBS incomplete Freund’s adjuvant (IFA) and a mix of the homogenized 4T1 cancer cells emulsified with IFA, respectively. Also, in the third group, the last immunization was contained just the homogenized cancer cells. Tumor induction was performed with 4T1 cells injection at the 4th mammary fat pad of each mouse. Tumor diameter and the number of macroscopic metastatic nodules on the lungs’ surface were investigated two weeks after the last immunization. We found that the immunization of mice with homogenized 4T1 cancer cells and IFA significantly inhibited 4T1 tumors’ growth. Also, metastatic colonies in the lungs significantly decreased in mice which immunized with 4T1 cancer cells and IFA. Overall, the effective induction of immune response by the vaccine used in our study seems to have prevented cancer cells migration and metastasis to other organs. However, precise immunological studies are required to determine the mechanism of such a vaccine.