Mesenchymal stem cells (MSCs) have recently been shown to home to tumors and contribute to the formation of the tumor-associated stroma. In addition, MSCs can secrete paracrine factors to facilitate tumor progression. However, the involvement of MSC-derived cytokines in colorectal cancer (CRC) angiogenesis and growth has not been clearly addressed. In this study, we report that interleukin-8 (IL-8) was the most highly upregulated pro-angiogenic factor in MSCs co-cultured with CRC cells and was expressed at substantially higher levels in MSCs than CRC cells. To evaluate the effect of MSC-derived IL-8 on CRC angiogenesis and growth, we used MSCs that expressed small hairpin (interfering) RNAs (shRNA) targeting IL-8 (shIL-8-MSCs). We found that MSC-secreted IL-8 promoted human umbilical vein endothelial cell (HUVEC) proliferation and migration, tube-formation ability and CRC cell proliferation. Additionally, in vivo studies showed that MSCs promoted tumor angiogenesis partially through IL-8. Taken together, these findings suggest that IL-8 secreted by MSCs promotes CRC angiogenesis and growth and can therefore serve as a potential novel therapeutic target.
Although molecular data have revealed huge amounts of plant diversity, interpreting genetic diversity into entities corresponding to species is still challenging. Taxonomic ranking based on genetic distance has been used extensively, but the results have been open to dispute, while the application of the strategy to plants has been restricted to a small number of cases. Here, levels of internal transcribed spacer 2 (ITS2) sequence variation were examined from 17,203 sequences, representing 5,439 species in 113 genera of seed plants, to ascertain the association between species status and their molecular divergence. Our results showed that, although the average genetic distances of sister species (AGDS) varied among angiosperms, the mean value was 3.98% and seemed not to be influenced by higher-level hierarchical classification or life history. AGDS was also stable within the major lineages of the gymnosperms but at approximately half the value of angiosperms, except for the Gnetidae, where the AGDS almost equaled that of angiosperms. We found that these AGDS discrepancies, associated with the rates of molecular evolution, cannot simply be attributed to generation-time differences, and highlight the complex life histories of plants. Our results provide general ITS2 thresholds in seed plants, and suggest their use in species identification.
As a complicated micro-ecosystem, gut microbes are closely related to metabolic disease, immune disease and tumor (such as constipation. Long-term constipation would cause intestinal mucosal injury, enteritis, ileus, etc., thus inducing intestine cancer). In this research, intestine cancer model group and Codonopsis foetens treatment group were successfully constructed, and the variation of intestinal microbes were analyzed by 16S rRNA sequence. Results showed that there were changes in bacteria abundance of Firmicutes, Bacteroidetes, Proteobacteria, Deferribacteres, Tenericutes, and Actinobacteria, etc. Codonopsis foetens could directly or indirectly affect the growth and metabolism of Deferribacteres by altering the nutritional ingredient and pH value of intestine “medium”, thus affecting the occurrence and development of intestinal microbes.
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