Study the effect of indomethacin administration on breast tumor growth and iNOS gene expression in tumor-bearing mice

Breast cancer is a public health concern among the women. iNOS is stated by the effect of various inflammatory factors and is thus called inducible NOS. Investigating iNOS expression is a potent tool for understanding effective molecular parameters in tissue and cellular responses to external factors. In this research study, iNOS expression in mice with breast cancer was investigated and the effects of various doses of indomethacin on the iNOS gene expression in breast tumors was evaluated. 4T1 cells were grown in RPMI 1640 Medium. 200 µl of cell suspension (107 cells)were injected into the mice right flank, subcutaneously. 35 Balb/C albino mice divided into five groups each group consist of 7 mice. First group was healthy control group, second group was tumor control, and the 3rd, 4th and 5th groups were treated by 25μg, 50μg and 100μg of indomethacin, respectively. The rate of breast tumor growth was measured in treated groups for two months. The levels of iNOS gene expression was determined using real time RT-PCR technique. Our results demonstrated, iNOS expression in tumor tissue increased with the growth of breast cancer cells. Furthermore, Administration of 25μg and 100μg indomethacin neither had significant effect on breast tumor growth nor effect on iNOS gene expression. While 50μg indomethacin decreased the tumor growth (P> 0.05) and decreased iNOS gene expression. Further studies such as evaluating the effects of indomethacin on the other anti-tumor immunosuppressing factor and additional tests western blot, flow cytometry and immunohistochemistry recommended in order to obtain more practical findings.