Claudin14 promotes colorectal cancer progression via the PI3K/AKT/mTOR pathway.

Colorectal cancer is the third leading cancer in the world in terms of incidence and mortality. The role of differentially expressed Claudin-14 (CLDN14) in CRC has not been reported. We observed that CLDN14 was associated with the progression of CRC. Our functional studies have shown that CLDN14 promoted the proliferation of CRC cells. In addition, CLDN14 also increased the migration and invasion of CRC cells. In vivo experiments also showed that CLDN14 promoted the growth of colorectal cancer via the PI3K/AKT/mTOR. In summary, our research suggests that CLDN14 promotes the progression of colorectal cancer. Our findings may provide new strategies for clinical management and patient prognosis of CRC.

A Comparison Study of Age and Colorectal Cancer-Related Gut Bacteria.

Intestinal microbiota is gaining increasing interest from researchers, and a series of studies proved that gut bacteria plays a significant role in various malignancies, especially in colorectal cancer (CRC). In this study, a cohort of 34 CRC patients (average age=65 years old), 26 young volunteers (below 30 years old), and 26 old volunteers (over 60 years old) was enrolled. 16S ribosomal RNA gene sequencing was used to explore fecal bacteria diversity. The operational taxonomic unit (OTU) clustering analysis and NMDS (non-metric multidimensional scaling) analysis were used to separate different groups. Cluster of ortholog genes (COG) functional annotation and Kyoto encyclopedia of genes and genomes (KEGG) were used to detect enriched pathways among three groups. Community separations were observed among the three groups of this cohort. Clostridia, Actinobacteria, Bifidobacterium, and Fusobacteria were the most enriched bacteria in the young group, old group, and CRC group respectively. Also, in the young, old, and CRC group, the ratio of Firmicutes/Bacteroidetes was increased sequentially despite no statistical differences. Further, COG showed that transcription, cell wall/membrane/envelope biogenesis, inorganic ion transport and metabolism, and signal transduction mechanisms were differentially expressed among three groups. KEGG pathways associated with ABC transporters, amino sugar and nucleotide sugar metabolism, arginine and proline metabolism, and aminoacyl-tRNA biosynthesis also showed statistical differences among the three groups. These results indicated that the intestinal bacterial community varied as age changed and was related to CRC, and we discussed that specific bacteria enriched in the young and old group may exert a protective function, while bacteria enriched in the CRC group may promote tumorigenesis.