GFP Reporter Cell Line - HGC-27

Liver metastasis (LM) is one of the most common distant metastases of gastric cancer (GC). However, the underlying mechanisms of gastric cancer liver metastasis (GC-LM) remain unclear. Here, researchers identified tumor-secreted proteins associated with GC-LM and explored the mechanism by which these proteins remodel the liver microenvironment to promote GC-LM development. Results showed that LBP was identified as a key secreted protein associated with GC-LM and was associated with poor prognosis in gastric cancer patients. LBP activates the TLR4/NF-κB pathway, promoting the secretion of TGF-β1 by hepatic macrophages, which in turn activates hepatic satellite cells (HSCs) and guides the formation of hepatic fibrotic polymorphonuclear leukocytes (PMNs). Furthermore, TGF-β1 enhances the migration and invasion of metastatic gastric cancer cells in the liver. Therefore, selective targeting of the TGF-β/Smad signaling pathway with galunisertib demonstrated its efficacy in preventing GC-LM in vivo.

To verify this hypothesis, researchers constructed a mouse model and pretreated it with recombinant protein to investigate the effects of exogenous LBP on liver metastasis (LM) and the hepatic microenvironment (Figure 1A). Mice were injected with recombinant LBP (reLBP) or IgG via the tail vein every other day for 2 weeks, followed by intrasplenic injection of luciferase-labeled GC cells. As shown in Figure 1B, intrasplenic injection of AGS cells significantly exacerbated the progression of liver metastasis with exogenous LBP, ultimately leading to a significant increase in the liver metastatic burden. Notably, bioluminescence imaging (BLI) analysis showed that even in the first week after intrasplenic injection, exogenous LBP pretreatment significantly increased cancer cell colonization in the liver (Figure 1B). Furthermore, daily bioluminescence signal analysis during the first week after intrasplenic injection of GFP-HGC-27 cells consistently indicated that LBP promoted the colonization and proliferation of GC cells in the liver in the early stages (Figure 1C). Mice were sacrificed on day 7 after intrasplenic injection. Representative photographs and H&E staining showed increased dissemination and proliferation of GC cells in the liver after reLBP pretreatment (Figure 1D). Immunofluorescence analysis and flow cytometry analysis of GFP+ HGC-27 cells in liver sections further confirmed this result (Figure 1E-F).

Figure 1. LBP promotes GC cell colonization and outgrowth in the liver at the early stages by inducing intrahepatic fibrotic PMN formation in the pre-modelling mouse model. (Xie L, et al., 2023)