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Cancer stem cells (CSCs) are capable of generating multiple types of cells and play a vital role in promoting gastric cancer (GC) progression. Our previous research indicated that gastric CSCs with surface markers of CD44+ were more invasive compared to CD44- CD90+ CSCs (CD90+ CSCs), whereas CD90+ CSCs exhibited higher levels of proliferation than CD44+ CSCs. However, the mechanism and characteristics of marker-positive gastric CSCs are poorly understood. In this study, we profiled expression of miRNAs and mRNAs in CD44+ CSCs, CD90+ CSCs, and CD44- CD90- cell subtype (control) from SNU-5 cells by microarray analysis. Our results suggested some specially expressed miRNA-mRNA pairs in CD44+ and CD90+ CSCs. We performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to analyze the correlation and function of those pairs. We also validated the pairs that may play roles in metastasis by qRT-PCR. In CD44+ CSCs, we observed hsa-miR-15b-5p was up-regulated and its target genes AMOT, USP31, KALRN, EPB41L4B, ATP2B2, and EMC4 were down-regulated, which may relate to invasion and migration. In CD90+ CSCs, we observed hsa-miR-3631-3p is up-regulated, while its target genes QKI, TRIM67 and HMGA2 are down-regulated, which is associated with proliferation. We also found that hsa-miR-1910-5p is up-regulated while its target gene QKI and HMGA2 are down-regulated in CD90+ CSCs. The screened miRNA-mRNA pairs give us new insight into the mechanism of different phenotypes and biomarkers capable of identifying and isolating metastatic and tumorigenic CSCs. Those miRNA-mRNA pairs may also act as treatment for GC., Competing Interests: None., (IJCEP Copyright © 2020.)

Unlabelled: Physically loading of paclitaxel (PTX) onto carbon nanotubes (CNTs) is achieved through immersion of poly(ethylene glycol) (PEG)-graft-single walled CNTs (PEG-g-SWNTs) or PEG-graft-multi-walled CNTs (PEG-g-MWNTs) in a saturated solution of PTX in methanol. After loading once the loading capacity (LD%) is 26% (w/w) and 36% (w/w) for PEG-g-SWNTs or PEG-g-MWNTs, respectively. With these PTX contents, PTX loaded PEG-g-SWNTs and PTX loaded PEG-g-MWNTs still have good dispersity in aqueous solution and individual CNTs can be observed in TEM images. PTX can be released from PEG-g-CNTs several times faster than from free PTX but still in a sustained profile with less than 40% of PTX being released in 40 days at pH 7 or 5. In vitro cytotoxicity of samples is evaluated in HeLa cells and MCF-7 cells. PEG-g-SWNTs and PEG-g-MWNTs show low cytotoxicity in both cells with insignificant effects on the cell proliferation rates. However, both PTX loaded PEG-g-SWNTs and PTX loaded PEG-g-MWNTs show high efficacy to kill HeLa cells and MCF-7 cells, as reflected by IC(50) lower than free PTX. Therefore, PTX loaded PEG-g-CNTs are promising for cancer therapeutics., Keywords: carbon nanotubes, poly(ethylene glycol), drug delivery, cancer therapy, nanomedicine.