Analysis of high risk factors for chronic atrophic gastritis.

Background: Screening for chronic atrophic gastritis (CAG) is crucial for the prevention and early detection of gastric cancer. Endoscopy is the main method of CAG diagnosis, with high training requirements and limited accuracy, making it difficult to popularize. The study attempts to improve the positive rate and accuracy of CAG screening through non-invasive testing. Methods: A total of 2564 patients who underwent gastroscopy were included in this study. The results of gastroscopic evaluation, histological biopsy results (including H. pylori biopsy), urea breath test (UBT) results, serum pepsinogen, and testosterone were statistically analyzed. Results: We found significant differences in the diagnosis of CAG between endoscopy and histological biopsy. Pepsinogen II and pepsinogen I/II ratio were more useful for the diagnosis of CAG compared with pepsinogen I. The risk of CAG was increased when pepsinogen II exceeded 11.05 µg/L, and the pepsinogen I/II ratio was less than 3.75. CAG positivity was higher in patients with positive H. pylori infection on UBT screening. In addition, higher levels of testosterone, SHBG and HSD17B2, and lower level of GNRH1 were found in CAG mucosa. Patients with high serum testosterone had a higher risk of CAG. Conclusion: CAG screening should be combined with endoscopic evaluation, biopsy, and other non-invasive tests. Non-invasive tests include the combination of serum pepsinogen II protein and pepsinogen I/II ratio and high level of serum testosterone. UBT combined with serum pepsinogen testing may improve the positive rate of CAG and reduce gastric mucosal damage from multiple biopsies.

Regulatory T Cells Promote Overexpression of Lgr5 on Gastric Cancer Cells via TGF-beta1 and Confer Poor Prognosis in Gastric Cancer.

Background: The leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5) is considered a cancer stem cell marker, and is often overexpressed in tumors. The interaction between Lgr5 and the immune-related tumor microenvironment is not completely understood. The aim of this study was to examine the role of Lgr5 in the microenvironment of gastric cancer (GC), and to explore possible immunological mechanisms influencing Lgr5 expression that are governed by regulatory T cells. Methods: Lgr5 expression was examined in 180 GC tumors by immunohistochemistry, and in 80 pairs of GC tumors for analysis of Th1/Th2 cytokines by ELISA. In addition, SGC7901 cells were co-cultured with patient-derived Tregs, varying concentrations of TGF-ß1, TGF-ß1 neutralizing antibody, or TGF-ß receptor inhibitor SB431542, and Lgr5 and ß-catenin expression were examined by qRT-PCR and western blot. Results: In this study, an immunosuppressive microenvironment was associated with high Lgr5 expression in GC. Furthermore, Lgr5 expression was up-regulated in GC cells co-cultured with Tregs or treated with exogenous TGF-ß1. This up-regulation was partially inhibited by the TGF-ß1 neutralizing antibody, or TGF-ß1 receptor antagonist SB431542. ß-catenin was up-regulated with high Lgr5 expression induced by exogenous TGF-ß1, and this up-regulation was inhibited by SB431542. An increased number of Tregs and high Lgr5 expression in GC tissues were significantly associated with low overall survival. Conclusion: Tregs promoted increased Lgr5 expression in GC cells via TGF-ß1 and TGF-ß1 signaling pathway, which may involve activation of the Wnt signaling pathway. High Lgr5 expression via TGF-ß confer poor prognosis in gastric cancer.

Primary gastrointestinal stromal tumor of the liver treated with sequential therapy.

A 67-year-old female presented with a primary hepatic gastrointestinal stromal tumor that was detected by computed tomography and diagnosed based on histopathological and genetic analyses. The tumor was microscopically composed of spindle cells and epithelioid cells, and immunohistochemistry results showed positive staining for CD117 and CD34 expression. A genetic analysis revealed a heterozygous point mutation and deletion in exon 11 of c-KIT. After an R0 resection, imatinib mesylate was administered for 1 year until its use was discontinued due to severe side effects. Two years after the original operation, the tumor recurred in the residual liver and was completely resected again. Imatinib mesylate was administered for 2 years until it was replaced by sunitinib malate because of disease progression. The patient has survived for 53 mo after undergoing a sequential therapy consisting of surgical excision, imatinib and sunitinib.

Role of plasmacytoid dendritic cells and inducible costimulator-positive regulatory T cells in the immunosuppression microenvironment of gastric cancer.

Regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs) play important roles in the immune escape of cancer. In this study, we investigated pDCs and pDC-induced inducible costimulator (ICOS)(+) Treg populations in peripheral blood from gastric cancer (GC) patients and healthy donors by flow cytometry. The distribution of these cells in carcinoma tissue, peritumor tissue, and normal gastric mucosa was detected by immunohistochemistry. Plasma and tissue concentration of the cytokines such as interleukin-10 and transforming growth factor-ß1 were also measured. We found that the numbers of pDCs, Tregs, and ICOS(+) Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS(+) Tregs were found distributing mainly in carcinoma tissue, whereas pDCs were mainly found in peritumor tissue. Moreover, the Foxp3(+) ICOS(+) /Foxp3(+) cell ratio in carcinoma and peritumor tissue were higher than that in normal tissue. There were more ICOS(+) Tregs in tumor and peritumor tissue of late-stage GC patients. There was a positive correlation between pDCs and ICOS(+) Tregs in peripheral blood and peritumor tissue from GC patients. In conclusion, pDCs may play a potential role in recruiting ICOS(+) Tregs, and both participate in the immunosuppression microenvironment of GC.

Anti-tumor effects of Mfn2 in gastric cancer.

Mitofusin-2 (Mfn2) is a mitochondrial outer membrane protein involved in mitochondrial fusion. Its mutation can cause Charcot-Marie-Tooth disease. Recent studies of Mfn2 in cancer research have not included gastric cancer. We confirmed that Mfn2 expression was lower in tumor tissue than in normal gastric mucosal tissue and that it was negatively correlated with tumor size, indicating an anti-tumor role for Mfn2. In vitro experiments showed that Mfn2 overexpression suppressed gastric cancer cell proliferation and colony formation, weakened the invasion and migratory ability of cancer cells by downregulating MMP-2 and MMP-9, halted the cell cycle and induced apoptosis. Western blotting indicated the likely involvement of P21 and PI3K/Akt signaling. Therefore, Mfn2 is a potential anti-tumor gene and a potential therapeutic target for treating gastric cancer. The progress of gastric cancer may be delayed by controlling Mfn2 expression.