Mouse Sting1 Stable Cell Line - 4T1

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and effective therapeutic strategies for it remain lacking. Studies have indicated that the Stimulator of Interferon Genes (STING) can either inhibit or promote cell migration across various cancer types; however, its specific mechanism of action in TNBC remains unclear. To investigate this issue, researchers established a murine TNBC cell line overexpressing STING and evaluated its migratory and proliferative behaviors. The results demonstrated that STING overexpression significantly inhibited cell migration but had no effect on cell proliferation. Furthermore, STING overexpression significantly upregulated the expression levels of Itgb1 and Itga6, while exerting no significant impact on the expression of Icam1, Cxcl3, Itgb2, Lama5, or Rhoa. These findings highlight the potential role of STING in inhibiting cell migration, distinct from its established immunomodulatory functions.

Here, the researchers established STING-overexpressing E0771 and 4T1 cell lines (Figure 1A). Subsequently, the researchers performed Transwell migration assays (Figure 1B) to assess the impact of STING on cellular migratory capacity. The results demonstrated that, compared to the control groups, the migratory capacity of the STING-overexpressing cells was significantly reduced-specifically, the migration rate decreased by approximately 61.2% in E0771 cells and by approximately 58.0% in 4T1 cells (Figures 1C and 1D). These findings indicate that intrinsic STING protein within tumor cells is capable of inhibiting the migration of these two distinct types of triple-negative breast cancer (TNBC) cells. To rule out the possibility that the reduced cell counts observed in the Transwell assays stemmed from differences in cell proliferation rather than differences in migratory capacity, the researchers monitored cell growth over a period of four consecutive days under culture conditions identical to those used for the migration assays. The results showed that, in both the E0771 and 4T1 cell lines, the cell growth curves for the STING-overexpressing groups were essentially identical to those of the control groups (Figure 1E). Therefore, the observed decline in Transwell migratory capacity was not attributable to alterations in the rate of cell proliferation.

Figure 1. Tumor-intrinsic STING reduces cell migration in two distinct TNBC cell lines. (Xie J, et al., 2026)