ABSTRACT
Objective:To investigate the characteristics of bacterial community in upper gastrointestinal tumors.Methods:The study population was patients with upper gastrointestinal tumors (esophageal cancer and gastric cancer). Gastroscopy was performed on the enrolled patients ( n=17), and the specimens were taken from the tumor sites. At the same time, non-tumor tissues more than 4 cm away from the tumor tissues were taken as the control. After total DNA was extracted and purified, high-throughput 16S DNA gene sequencing was used to detect the microbiota in tumor tissues and control tissues. Bioinformatics analysis was carried out and the differences between groups were compared. Results:16S DNA PCR showed that there was no significant difference in bacterial load between tumor tissues and control tissues. The α-diversity and β-diversity indexes showed that the community composition of the two groups was similar; the samples were discrete and the colony composition was different, but there was no significant difference between the two groups. The results of Venn diagram showed that there were more operational taxonomic units (OTUs) in non-tumor tissues than in tumor tissues (2 068 vs 1 358), indicating that the bacterial species in normal tissues were more abundant than those in tumor tissues. Compared with the control tissues, the percentages of Prevotellaceae ( Prevotella), Lactobacaceae ( Lactobacillus) and Fusobacteriaceae ( Fusobacterium) in tumor tissues were relatively higher (the average percentage was more than twice that of the control). Further paired comparison of the top ten bacteria in the family and genus abundance of the two groups of samples showed that Pseudomonas decreased significantly in tumor tissues at the family ( P=0.041) and genus ( P=0.041) levels, while Prevotella was significantly enriched in tumor tissues at the family ( P=0.031) and genus ( P=0.007) levels. Conclusions:The bacterial community in the tumor microenvironment of the upper gastrointestinal tumor changed, and the species enriched in the tumor site were mainly oral common anaerobic bacteria, such as Prevotellaceae ( Prevotella), Lactobacaceae ( Lactobacillus) and Fusobacteriaceae ( Fusobacterium), especially Prevotellaceae ( Prevotella).
ABSTRACT
This study is to investigate the effects of ubenimex on tumor cell invasion and apoptosis, dose relationship and mechanism. Immunofluorescence staining was performed to detect the expression of CD13 in HT-1080 cells. MTT assay was used to analyze the effect of ubenimex on cell proliferation. Annexin V-EGFP/PI was used to detect apoptotic cells by flow cytometry. Cell cycle was analyzed using flow cytometry. Ala-pNA was used as substrate to evaluate the effect of ubenimex on the aminopeptidase activity. Transwell assay was used to analyze the effect of ubenimex on cell invasion and migration ability. Western blotting was used to detect the expression level of CD13. MMP activity was analyzed using gelatin zymography. The results showed that ubenimex at high concentration inhibited the proliferation of HT-1080 cells (IC50: 3.8 mg x mL(-1)), and induced cell apoptosis. Cell cycle was blocked at G1 phase. Ubenimex at low concentration inhibited the aminopeptidase activity of HT-1080 cells (IC50: 8.3 microg x mL(-1)) and inhibited cell invasion, but it had no effects on the cell migration and proliferation. Ubenimex had no effects on CD13 expression and MMP activity. In conclusion, ubenimex at low concentration can inhibit the invasion ability of tumor cells by directly inhibiting the aminopeptidase activity; ubenimex at high concentration can inhibit the proliferation of tumor cells and induce cell apoptosis by a CD13-independent pathway.