CMTM3 protects the gastric epithelial cells from apoptosis and promotes IL-8 by stabilizing NEMO during Helicobacter pylori infection

CMTM6 promotes hepatocellular carcinoma invasion and metastasis and tumor-associated neutrophil immunoinfiltration through the Wnt/β-catenin pathway

BACKGROUND

CMTM6 has been closely associated with the onset and progression of various tumor types. However, the precise mechanism by which CMTM6 operates in hepatocellular carcinoma remains elusive, necessitating further investigation.

METHODS

Expression levels of CMTM6 in hepatocellular carcinoma tissues and cells were analyzed using immunohistochemistry and quantitative real-time PCR. The correlation between CMTM6 expression in hepatocellular carcinoma tissues and clinical pathological characteristics, as well as patient prognosis, was investigated. Proliferation and apoptosis of hepatocellular carcinoma cells with silenced or overexpressed CMTM6 were assessed, alongside measurements of β-catenin and Wnt1 protein expression levels. In vivo research was conducted utilizing a murine subcutaneous transplantation model. Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed to elucidate the regulatory mechanism of CMTM6. Additionally, CD66b expression levels in tumor tissue were examined using immunohistochemistry, and the immune infiltration of CMTM6 and tumor-associated neutrophils (TANs) was analyzed.

RESULTS

Elevated expression levels of CMTM6 in hepatocellular carcinoma tissues and cells were found to be associated with poor patient prognosis. Overexpression of CMTM6 in hepatocellular carcinoma cells was demonstrated to promote cellular proliferation and inhibit apoptosis. Mechanistically, CMTM6 expression levels in hepatocellular carcinoma tissues were observed to positively correlate with β-catenin expression. GSEA and KEGG analysis revealed significant enrichment of CMTM6 in the Wnt/β-catenin pathway, indicating its involvement in pathway regulation. Furthermore, CMTM6 was found to be associated with immune infiltration of TANs in hepatocellular carcinoma tissues.

CONCLUSION

CMTM6 plays a pivotal role in the development and progression of hepatocellular carcinoma through regulation of the Wnt/β-catenin pathway via β-catenin. Moreover, CMTM6 demonstrates the capacity to promote immune infiltration of TANs in hepatocellular carcinoma tissues. Consequently, CMTM6 exhibits potential as both an early diagnostic marker and a novel therapeutic target for patients with hepatocellular carcinoma.

CMTM4 inhibits gastric tumorigenesis and metastasis

Background

CKLF-like MARVEL transmembrane domain-containing 4 (CMTM4) is involved in immune regulation and tumor progression; however, its role in gastric cancer (GC) remains unclear. This study explored the role and mechanism of CMTM4 in GC.

Methods

Immunohistochemistry was used to analyze CMTM4 expression in human gastric biopsied cells from patients with GC (N=23) or chronic superficial gastritis (N=23). To investigate the function of CMTM4 in GC cells, the gene CMTM4 was knocked down and overexpressed in human gastric adenocarcinoma cell line AGS. The gene CMTM4 was overexpressed in AGS cells and human gastric cell line SGC7901. Cell Counting Kit 8 (CCK-8) and cell clonogenic assays were used to analyze the proliferation of the GC cells. Flow cytometry was used to analyze the effects of CMTM4 on apoptosis and the cell cycle. Wound healing and transwell assays were used to analyze the migration and invasion of the gastric cells, respectively. The mechanism of CMTM4 in GC cells was explored using the tandem mass tags (TMTs) proteome and verified by western blot analysis.

Results

CMTM4 expression was more downregulated in the human GC tissues than the gastritis tissues. CMTM4 overexpression significantly inhibited the proliferation, migration, and invasion of the GC cells, whereas CMTM4 knockdown enhanced gastric cell proliferation (P>0.05), migration (P>0.05), and invasion (P>0.05). Flow cytometry showed that CMTM4 promoted apoptosis and resulted in G1/S arrest in the GC cells. In addition, the proteome and western blot results showed that STAT1 was significantly upregulated, and the STAT1 signaling pathways were enriched in the GC cells overexpressing CMTM4.

Conclusions

Our results suggest that CMTM4 plays a tumor-suppressive role in GC and may affect the growth, migration, and invasion of GC cells through the STAT1 signaling pathway. CMTM4 might have potential value as a prognosis marker and potential therapeutic target for GC therapy.

Indole-3-Lactic Acid Derived from Lacticaseibacillus paracasei Inhibits Helicobacter pylori Infection via Destruction of Bacteria Cells, Protection of Gastric Mucosa Epithelial Cells, and Alleviation of Inflammation

Indole-3-lactic acid (ILA) has exhibited antimicrobial properties. However, its role in inhibiting Helicobacter pylori infection remains elusive. This study investigated the inhibitory effect of ILA produced by Lacticaseibacillus paracasei on H. pylori, which was further confirmed by cell and animal experiments. 5 mg/mL ILA was sufficient to directly inhibit the growth of H. pylori in vitro, with a urease inhibitory activity reaching 60.94 ± 1.03%, and the cell morphology and structure were destroyed. ILA inhibited 56.5% adhesion of H. pylori to GES-1 and significantly reduced the number of apoptotic cells. Furthermore, ILA suppresses H. pylori colonization by approximately 38% to 63%, reduced inflammation and oxidative stress in H. pylori-infected mice, and enhanced the enrichment and variety of gut microbiota, notably fostering the growth of beneficial bacteria such as Lactobacillus and Bifidobacterium strains. The results support that ILA derived from Lactobacillus can be applicated as a novel prebiotic in anti-H. pylori functional foods.

Research insights into the chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family (CMTM): their roles in various tumors

The chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing (CMTM) family includes CMTM1-8 and CKLF, and they play key roles in the hematopoietic, immune, cardiovascular, and male reproductive systems, participating in the physiological functions, cancer, and other diseases associated with these systems. CMTM family members activate and chemoattract immune cells to affect the proliferation and invasion of tumor cells through a similar mechanism, the structural characteristics typical of chemokines and transmembrane 4 superfamily (TM4SF). In this review, we discuss each CMTM family member's chromosomal location, involved signaling pathways, expression patterns, and potential roles, and mechanisms of action in pancreatic, breast, gastric and liver cancers. Furthermore, we discuss several clinically applied tumor therapies targeted at the CMTM family, indicating that CMTM family members could be novel immune checkpoints and potential targets effective in tumor treatment.

AUF1-mediated inhibition of autophagic lysosomal degradation contributes to CagA stability and Helicobacter pylori-induced inflammation

CagA, a virulence factor of Helicobacter pylori (H. pylori), is known to drive inflammation in gastric epithelial cells and is typically degraded through autophagy. However, the molecular mechanism by which CagA evades autophagy-mediated degradation remains elusive. This study found that H. pylori inhibits autophagic flux by upregulating the expression of AU-rich element RNA-binding factor 1 (AUF1). We confirmed that AUF1 does not affect autophagy initiation but instead hampers lysosomal clearance, as evidenced by treatments with 3-MA, CQ and BafA1. Upregulated AUF1 stabilizes CagA protein levels by inhibiting the autolysosomal degradation of intracellular CagA in H. pylori-infected gastric epithelial cells. Knocking down AUF1 promotes CagA degradation, an effect that can be reversed by the lysosome inhibitor BafA1 and CQ. Transcriptome analysis of AUF1-knockdown gastric epithelial cells infected with H. pylori indicated that AUF1 regulates the expression of lysosomal-associated hydrolase genes, specifically CTSD, to inhibit autolysosomal degradation. Moreover, we observed that knockdown of AUF1 enhanced the stability of CTSD mRNA and identified AUF1 binding to the 3'UTR region of CTSD mRNA. AUF1-mediated downregulation of CTSD expression contributes to CagA stability, and AUF1 overexpression leads to an increase in CagA levels in exosomes, thus promoting extracellular inflammation. In clinical gastric mucosa, the expression of AUF1 and its cytoplasmic translocation are associated with H. pylori-associated gastritis, with CagA being necessary for the translocation of AUF1 into the cytoplasm. Our findings suggest that AUF1 is a novel host-positive regulator of CagA, and dysregulation of AUF1 expression increases the risk of H. pylori-associated gastritis.