Detection and Enumeration of Circulating Tumor Cells with Invasive Phenotype

Size-resolved counting of circulating tumor cells on pinched flow-based microfluidic cytometry

Precise cell detecting and counting is meaningful in circulating tumor cells (CTCs) analysis. In this work, a simple cyclic olefin copolymer (COC) microflow cytometer device was developed for size-resolved CTCs counting. The proposed device is constructed by a counting channel and a pinched injection unit having three channels. Through injection flow rate control, microspheres/cells can be focused into the centerline of the counting channel. Polystyrene microspheres of 3, 9, 15, and 20 µm were used for the microspheres focusing characterization. After coupling to laser-induced fluorescence detection technique, the proposed device was used for polystyrene microspheres counting and sizing. A count accuracy up to 97.6% was obtained for microspheres. Moreover, the proposed microflow cytometer was applied to CTCs detecting and counting. To mimic blood sample containing CTCs and CTCs mixture with different subtypes, an MDA-MB-231 (human breast cell line) spiked red blood cells sample and a mixture of MDA-MB-231 and MCF-7 (human breast cell line) sample were prepared, respectively, and then analyzed by the developed pinched flow-based microfluidic cytometry. The simple fabricated and easy operating COC microflow cytometer exhibits the potential in the point-of-care clinical application.

LINC00857 promotes cell proliferation and migration in colorectal cancer by interacting with YTHDC1 and stabilizing SLC7A5

Colorectal cancer (CRC) is one of the most lethal malignances in humans. Hence, it is of great significance to identify regulatory molecules in CRC progression. Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) are involved in cancer malignancy. It has been reported that long intergenic non-protein coding RNA 857 (LINC00857) acts as a vital oncogene in many types of cancer by promoting cell proliferation and migration. However, the role of LINC00857 in CRC remains unclear. In the present study, LINC00857 was upregulated in CRC tissue samples and cells. Next, in vitro loss-of-function experiments demonstrated that LINC00857 knockdown suppressed CRC cell viability, proliferation and migration, as well as epithelial-mesenchymal transition and increased cell apoptosis. Mechanistically, LINC00857 abundantly interacted with the RNA-binding protein YTH domain containing 1 (YTHDC1). YTHDC1 ultimately combined with solute carrier family 7 member 5 (SLC7A5) and increased SLC7A5 mRNA stability. Finally, a series of rescue experiments indicated that LINC00857 promoted the proliferation and migration of CRC cells by regulating mRNA stability. Thus, the present findings illustrated that LINC00857 functions as an oncogene in CRC cells via the YTHDC1/SLC7A5 axis.