Immortalized Human Gastric Epithelial Cells-SV40

H. pylori-infected Macrophage Culture Medium Accelerates Disruption of the Gastric Mucosal Barrier

The Group 1 carcinogen Helicobacter pylori infect more than half of the world's population and causes chronic gastritis by interacting with immune cells in the gastric mucosa. Macrophages that appear at infection sites release inflammatory agents including CCL3 which causes mucosal damage but its pathogenic pathways remain unknown.

Chemokines released by macrophages play vital roles in inflammatory processes. Wei's team investigated how substances released by macrophages infected with H. pylori affect inflammation and damage in gastric mucosa tissue. Both immortalized human gastric epithelial cells (GES-1) and human gastric cancer cell line MKN28 were exposed to supernatant from human leukemia monocytic cells (THP-1) infected with H. pylori. H. pylori-infected macrophage medium (HMC) showed a significant reduction in TEER when compared to normal medium (NC), macrophage medium (MC), and H. pylori medium (HC) (Fig. 1A). The HMC treatment resulted in lower levels of tight junction proteins ZO-1 and Occludin according to the findings in Figures 1B and C. HMC caused disruption of cell tight junctions (Fig. 1D). H. pylori medium was found harmless to gastric mucosa so researchers chose NC and MC as control mediums for further experiments. HMC reduced cell viability and triggered apoptosis (Fig. 1G-H), and inhibited proliferation (Fig. 1I and J). H. pylori-infected macrophage medium leads to increased inflammation in gastric mucosa while breaking down the mucosal barrier.

Fig. 1. H. pylori-infected macrophage medium disrupts the gastric mucosa barrier and promotes inflammation (Wei Y F, Li X, et al., 2024).

NALCN Exerts an Inhibitory Effect on the Biological Function of GC Cells

Research first discovered NALCN during neurological studies before recognizing its important role in cancer metastasis. Li's team seeks to understand NALCN's essential role in gastric cancer development and its influence on immune cell distribution in the tumor microenvironment.

Analysis of RNA sequencing data from fresh frozen tumor and adjacent non-tumor tissues in 22 GC cases revealed that GC patients with low NALCN expression experience worse disease outcomes. The expression of NALCN mRNA and protein showed a significant reduction in GC cells (Fig. 2A). To understand NALCN's role in GC, they initiated three distinct NALCN knockdowns (siNALCN#1, siNALCN#2, siNALCN#3). NALCN expression levels decreased significantly in AGS and GES-1 cells after siRNA knockdown (Fig. 2A and B). Both cell types showed increased cell proliferation, colony formation abilities, and migration after knockdown (Fig. 2D–F). The knockdown of NALCN raised cyclin D1 protein levels while reducing G0/G1 phase cells and increasing G2/M phase cells according to Figure 2G and Figure 2H respectively and led to lower apoptosis rates in AGS and GES-1 cells as seen in Figure 2I. The results demonstrate that NALCN acts as an inhibitor of gastric cancer cell functionality.

Fig. 2. Effect of NALCN knockdown on biological function of GC cells (Li XW, Wu N, et al., 2025).