RESUMO
Objective:To explore the expression of long non-coding RNA (lncRNA) HAGLR in breast cancer and its effect on the prognosis of breast cancer, and to construct a competitive endogenous RNA (ceRNA) network.Methods:The Atlas of Genetics and Cytogenetics in Oncology and Haematology website was used to search for HAGLR chromosome gene mapping and transcript expression. The lnclocater website was used to predict the subcellular localization of HAGLR, and the differential expression of HAGLR in breast cancer tissues and adjacent tissues was analyzed by using lnCAR database. The patients in lnCAR database were divided into HAGLR high expression group and HAGLR low expression according to HAGLR expression. The Kaplan-Meier method was used to analyze the overall survival (OS) and metastasis-free survival, which was verified by using UCSC Xena database. lnCAR database was used to search the co-expressed genes of HAGLR. The top 200 co-expressed genes were submitted to the Metascape website for Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis, and protein interaction network (PPI) was constructed. Starbase, a bioinformatics online analysis website, was used to predict HAGLR targeting mircoRNA (miRNA) and mRNA that directly encoded proteins. ceRNA network of HAGLR was constructed with Cytoscape3.8 software.Results:HAGLR gene was localized in 2q31.1 and mainly distributed in cytoplasm. The expression level of HAGLR in breast cancer tissues was higher than that in adjacent tissues, and the difference was statistically significant ( P < 0.001). lnCAR database and UCSC Xena database analysis showed that OS in HAGLR high expression group was worse than that in HAGLR low expression group (all P < 0.01). lnCAR database, the metastasis-free survival in HAGLR high expression group was worse than that in HAGLR low expression group ( P = 0.030). Among the top 200 HAGLR co-expressed genes, 129 genes were negatively correlated with HAGLR and 71 genes were positively correlated with HAGLR. KEGG pathway analysis showed that HAGLR was related to metabolic pathways, MAPK signaling pathway, JAK-STAT signaling pathway and cancer pathway. GO annotation analysis showed that HAGLR was mainly enriched in cell cycle, centromeric complex assembly, mitotic progression, protein kinase binding, kinase activity regulation, cell response to DNA damage stimulation and other functions. hsa-miR-130b-3p, hsa-miR-1245b-5p, hsa-miR-182b-5p, hsa-miR-512-3p, hsa-miR-302b-3p, hsa-miR-185b-5p, hsa-miR-106b-5p were HAGLR targeting miRNA. Conclusions:HAGLR is highly expressed in breast cancer tissues, and it may be a biomarker for predicting the prognosis of breast cancer.
RESUMO
Nisin is an antimicrobial peptide widely used in food industry. In this study, Nisin A production in Lactococcus lactis ATCC 11454 was improved by overexpression of Nisin A structural gene nisA through introducing a shuttle expression vector pMG36ek-nisA and an integrated vector pDG780-nisA into the host strain. The differences of growth profiles and Nisin A production level between the two obtained genetic engineering strains FMM1/FMM2 and the parent strain were investigated. Our results show that while the growth profile (the growth rate, biomass and pH) of FMM1 was similar to the parent strain, its Nisin A production increased 31%. In contrast, the biomass of FMM2 was notably lower than the parent strain, while its yield of Nisin A enhanced slightly. The transcription level of genes involved in Nisin A biosynthesis in both engineering strains was further detected by RT-PCR. We found that all the 11 Nisin A biosynthetic genes in FMM1 and FMM2 had a higher transcription level than those in the parent strain, and these genes exhibited more significant increasing degree of transcription level in FMM1 which hosted the autonomous replicating nisA gene. These data suggest that expression of nisA may act as a rate-limit factor in Nisin A biosynthesis. In conclusion, this work provides a new method to improve Nisin A production by increasing the transcription level of nisA, paving the way to further large-scale industrial production of Nisin A.