ABSTRACT
The aim of this study was to evaluate the chitin degradation potential and whole-genome sequence of Streptomyces diastaticus strain CS1801, which had been screened out in our previous work. The results of fermentation revealed that CS1801 can convert the chitin derived from crab shells, colloidal chitin and N-acetylglucosamine to chitooligosaccharide. Additional genome-wide analysis of CS1801 was also performed to explore the genomic basis for chitin degradation. The results showed that CS1801 possesses a chromosome with 5,611,479 bp (73% GC) and a plasmid with 1,388,284 bp (73% GC). The CS1801 genome consists of 7584 protein-coding genes, 90 tRNA and 21 rRNA operons. In addition, the results of genomic CAZyme analysis indicated that CS1801 comprises 103 glycoside hydrolase family genes, which could regulate the glycoside hydrolases that contribute to chitin degradation. The whole-genome information of CS1801 could highlight the mechanism underlying the chitin degradation activity of CS1801, strongly indicating that CS1801 is characterized by a substantial number of genes encoding chitinases and the complete metabolic pathway of chitin, conferring CS1801 with promising potential applicability in chitooligosaccharide production.
ABSTRACT
As novel non-invasive tumor diagnostic biomarkers, exosomal bioactive miRNAs have received increasing attention. Herein, the aim of this study is to explore the clinical values and roles of exosomal miR106b in lung cancer. The exosomal miR-106b level was much higher in the serum of patients with lung cancer than that in healthy volunteers. Also, the exosomal miR-106b level in the lung cancer patient serum was associated with TNM stages and lymph node metastasis. Furthermore, exosomal miR-106b enhanced the migrated and invasive ability of lung cancer cells and increased the MMP-2 and MMP-9 expression. Mechanistically, exosomal miR-106b could target PTEN, and promote lung cancer cell migration and invasion. More importantly, PTEN overexpression reversed the effect of exosomal miR-106b on lung cancer cell migration and invasion. Taken together, these findings indicate that exosomal miR-106b may be a promising diagnostic biomarker and drug target for patients with lung cancer.