Objective: To explore the effect of the supernatant of 4T1 murine breast cancer cell culture on arginase 1 (Arg-1) in ANA-1 macrophages in vitro by simulating the microenvironment of breast cancer.
Methods: The experimental ANA-1 macrophages were treated with the supernatant of 4T1 culture, and meanwhile, the control cells were cultured in the absence of the supernatant. Morphological changes of the ANA-1 macrophages were observed with a light microscope at 6, 8, 10, 24 hours, respectively. Real-time quantitative PCR (qRT-PCR) was performed to detect the levels of inducible nitric oxide synthase (iNOS) and Arg-1 mRNAs. Immunofluorescence and Western blotting were used to determine the levels of iNOS and Arg-1 proteins.
Results: The qRT-PCR indicated that the level of iNOS mRNA decreased in the experiment group compared with the control group, while Arg-1 mRNA level significantly increased compared with the control group and it reached a peak at the 8th hour. The immunofluorescence and Western blotting also demonstrated that Arg-1 protein expression was enhanced in the experimental group compared with the control group. However, iNOS protein expression was no significantly different between the experiment group and the control group.
Conclusion: The supernatant of 4T1 cell culture increases Arg-1 production in ANA-1 macrophages.