1Chitiniphilus shinanonensis type strain SAY3T is a strongly chitinolytic bacterium, 2 originally isolated from the moat water in Ueda, Japan. To elucidate the chitinolytic 3 activity of this strain, 15 genes (chiA-chiO) coding for putative chitin-degrading 4 enzymes were isolated from a genomic library. Sequence analysis revealed the genes 5
Chitiniphilus shinanonensis strain SAY3T is a chitinolytic bacterium isolated from moat water of Ueda Castle in Nagano Prefecture, Japan. Fifteen genes encoding putative chitinolytic enzymes (chiA-chiO) have been isolated from this bacterium. Five of these constitute a single operon (chiCDEFG). The open reading frames of chiC, chiD, chiE, and chiG show sequence similarity to family 18 chitinases, while chiF encodes a polypeptide with two chitin-binding domains but no catalytic domain. Each of the five genes was successfully expressed in Escherichia coli, and the resulting recombinant proteins were characterized. Four of the recombinant proteins (ChiC, ChiD, ChiE, and ChiG) exhibited endo-type chitinase activity toward chitinous substrates, while ChiF showed no chitinolytic activity. In contrast to most endo-type chitinases, which mainly produce a dimer of N-acetyl-D-glucosamine (GlcNAc) as final product, ChiG completely split the GlcNAc dimer into GlcNAc monomers, indicating that it is a novel chitinase.
Objective
Based on the GEO, TCGA and GTEx databases, we reveal the possible molecular mechanism of the variable shear factor QKI in epithelial mesenchymal transformation (EMT) of oesophageal cancer.
Methods
Based on the TCGA and GTEx databases, the differential expression of the variable shear factor QKI in oesophageal cancer samples was analysed, and functional enrichment analysis of QKI was performed based on the TCGA-ESCA dataset. The percent-spliced in (PSI) data of oesophageal cancer samples were downloaded from the TCGASpliceSeq database, and the genes and variable splicing types that were significantly related to the expression of the variable splicing factor QKI were screened out. We further identified the significantly upregulated circRNAs and their corresponding coding genes in oesophageal cancer, screened the EMT-related genes that were significantly positively correlated with QKI expression, predicted the circRNA-miRNA binding relationship through the circBank database, predicted the miRNA-mRNA binding relationship through the TargetScan database, and finally obtained the circRNA-miRNA-mRNA network through which QKI promoted the EMT process.
Results
Compared with normal control tissue, QKI expression was significantly upregulated in tumour tissue samples of oesophageal cancer patients. High expression of QKI may promote the EMT process in oesophageal cancer. QKI promotes hsa_circ_0006646 and hsa_circ_0061395 generation by regulating the variable shear of BACH1 and PTK2. In oesophageal cancer, QKI may promote the production of the above two circRNAs by regulating variable splicing, and these circRNAs further competitively bind miRNAs to relieve the targeted inhibition of IL-11, MFAP2, MMP10, and MMP1 and finally promote the EMT process.
Conclusion
Variable shear factor QKI promotes hsa_circ_0006646 and hsa_circ_0061395 generation, and downstream related miRNAs can relieve the targeted inhibition of EMT-related genes (IL11, MFAP2, MMP10, MMP1) and promote the occurrence and development of oesophageal cancer, providing a new theoretical basis for screening prognostic markers of oesophageal cancer patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.