MiR-99a-3p downregulates TRIM21 to promote gastric cancer development.

Gastric cancer (GC) stands as one of the most formidable malignancies worldwide. It is well-established that miRNAs play a crucial role in the initiation and progression of various human cancers. Among these, miR-99a-3p has been implicated in the pathogenesis of GC. In the context of our study, we embarked on the comprehensive examination of miR-99a-3p expression in GC cells. Additionally, we sought to establish a correlation between miR-99a-3p expression levels and the overall survival (OS) of GC patients, and our findings hinted at its potential role in predicting an unfavorable prognosis. To further investigate the functional implications of miR-99a-3p in GC, we conducted a series of cell-based experiments after successfully knocking down miR-99a-3p. These investigations uncovered a substantial inhibition of cellular events associated with tumor progression. Moreover, employing TargetScan, we identified Tripartite motif-containing protein 21 (TRIM21) as a putative target with a binding site for miR-99a-3p. Subsequent dual-luciferase reporter gene assay confirmed the direct interaction between miR-99a-3p and TRIM21. Western blot analysis validated the alteration in TRIM21 expression levels, revealing an upregulation upon miR-99a-3p knockdown. Building on these molecular findings, we extended our investigations to human GC tissues, where we observed a downregulation of TRIM21, which, notably, correlated with shorter overall survival. Lastly, to further solidify our conclusions, we conducted a series of in vitro and in vivo rescue experiments, collectively suggesting that miR-99a-3p promoted the progression of GC cells through the downregulation of TRIM21. In summary, our study comprehensively explored the role of miR-99a-3p in GC, revealing its association with unfavorable patient outcomes, functional implications in tumor progression, and a direct regulatory relationship with TRIM21. These findings collectively underscore the significance of miR-99a-3p in the pathogenesis of GC and present a potential therapeutic avenue for further investigation.

Intestinal microbiota analyses of five economic fishery resources in the South China Sea.

The investigation of intestinal microbiota can provide evidence for revealing the growth and development regulation, feeding habits, environmental adaptability and pollutant indication of marine organisms. To data, the intestinal microbiota of marine organisms in the South China Sea is relatively lacking. To supplement these information, we sequenced intestinal microbiota from five fishery resources (including Auxis rochei, A. thazard, Symplectoteuthis oualaniensis, Thunnus albacores, and Coryphaena equiselis) in the South China Sea using high-throughput Illumina sequencing technology. After filtering, a total of 18,706,729 reads were finally produced and then clustered into OTUs. The mean number of OTUs detected in A. rochei, A. thazard, C. equiselis, S. oualaniensis, and T. albacores was 127, 137, 52, 136, and 142, respectively. Although the Actinobacteria, Bacteroidetes, Cyanobacteria, Deferribacteres, Firmicutes, Proteobacteria, Spirochaetes, Tenericutes, [Thermi], and unclassified_Bacteria were the most abundant in the five species, Photobacterium is the most abundant microbiota. Meanwhile, intestinal microbiota showed species- and sampling sites- specificity, thus only 84 microbiota species were common to all species. Additionally, the potential functions of OTUs in the five species is mainly involved in the synthesis and metabolism of carbohydrate, amino acid, fatty acid and vitamin. This study can provide basic data for clarifying the diversity and species- specificity of intestinal microbiota of five species in the South China Sea, and help to improve the intestinal microbiota database of marine organisms.

Gut microbiota composition and functional prediction in diarrhea-predominant irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is common and difficult to treat and its pathogenesis is closely related to gut microbiota. However, differences in gut microbiota of patients in different regions make it more difficult to elucidate the mechanism of IBS. We performed an analysis of gut microbiota composition and functional prediction in Chinese patients with diarrhea-predominant IBS (IBS-D). METHODS: Fecal samples were obtained from 30 IBS-D patients and 30 healthy controls (HCs) in Nanchang, China. Using 16S gene sequence profiles, we analyzed the abundance of dominant microbiota at different taxonomy levels. Based on 16S information, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to predicting the function of gut microbiota. RESULTS: Compared to HCs, gut microbiota richness but not diversity was decreased in IBS-D patients. The abundant phyla Firmicutes, Fusobacteria and Actinobacteria decreased significantly, and Proteobacteria increased significantly in IBS-D patients. PICRUSt indicated that function expression of gut microbiota in IBS-D patients was up-regulated in metabolism of cofactors and vitamins, xenobiotics biodegradation and metabolism, and down-regulated in environmental adaptation, cell growth and death. CONCLUSIONS: Compared with the normal population in China, IBS-D patients are characterized by complex and unstable gut microbiota, which may influence inflammation and metabolism of the host.