Luciferase Reporter Cell Line - SW480

The microenvironment of distant organs plays a crucial role in regulating tumor metastasis. Here, researchers found that EFNB2 expression is upregulated in liver metastases (LM) of colorectal cancer (CRC), but not in lung metastases (PM) or primary CRC tumors. EFNB2 exhibits pro-tumorigenic effects on CRC liver metastases both in vitro and in vivo. EFNB2 promotes CRC liver metastasis via a forward signaling pathway through interaction with the EPHB4 receptor. The EFNB2/EPHB4 axis enhances LDLR-mediated cholesterol uptake in CRC liver metastases. Subsequently, the EFNB2/EPHB4 axis promotes LDLR transcription by regulating STAT3 phosphorylation. Blocking LDLR reverses the pro-CRC liver metastasis effect of the EFNB2/EPHB4 axis. Survival analysis using clinical data revealed that CRC LM patients with high EFNB2 expression had shorter survival compared to those with low EFNB2 expression. Inhibition of the EFNB2/EPHB4 axis significantly prolonged survival in a BALB/c nude mouse CRC LM model fed a high-cholesterol diet. These findings reveal the crucial role of the EFNB2/EPHB4 axis in cholesterol uptake regulation and its pro-tumor effect in CRC LM.

To verify the effect of the EFNB2/EPHB4 axis on CRC liver metastases (LM), researchers established LM models by injecting EFNB2-overexpressing cells or control SW480-luc cells into the spleen of nude mice, or by injecting them directly into the liver. In both the LM and liver injection models, inhibition of EPHB4 using siRNA and NVP-BHG712 significantly reduced EFNB2-promoted tumor growth (Figure 1D, E). PCNA staining also showed that blocking EPHB4 reversed EFNB2-promoted cell proliferation in both the LM and liver injection models (Figure 1F, G). Digestion and culture of LM tumor tissue (Figure 1H), CCK-8 and EdU experiments demonstrated that EFNB2 overexpression significantly promoted the in vitro proliferation of CRC LM cells (Figure 1I, J). These data indicate that EFNB2 promotes LM in CRC through interaction with the EPHB4 receptor.

Figure 1. The EFNB2-EPHB4 axis enhanced post-metastatic growth of CRC LM. (Xu C, et al., 2023)