Tumor-suppressive activity of sTRAIL on circulating CD44+ cells in patients with non-small cell lung cancer

Self-powered biosensing platform for Highly sensitive detection of soluble CD44 protein

In this study, a self-powered biosensor based on an enzymatic biofuel cell was proposed for the first time for the ultrasensitive detection of soluble CD44 protein. The as-prepared biosensor was composed of the co-exist aptamer and glucose oxidase bioanode and bilirubin oxidase modified biocathode. Initially, the electron transfer from bioanode to biocathode was hindered due to the presence of the aptamer with high insulation, generating a low open-circuit voltage (EOCV). Once the target CD44 protein was present, it was recognized and captured by the aptamer at the bioanode, thus the interaction between the target CD44 protein and the immobilized aptamer caused the structural change at the surface of the electrode, which facilitated the transfer of electrons. The EOCV showed a good linear relationship with the logarithm of the CD44 protein concentrations in the range of 0.5-1000 ng mL-1 and the detection limit was 0.052 ng mL-1 (S/N = 3). The sensing platform showed excellent anti-interference performance and outstanding stability that maintained over 97% of original EOCV after 15 days. In addition, the relative standard deviation (1.40-1.96%) and recovery (100.23-101.31%) obtained from detecting CD44 protein in real-life blood samples without special pre-treatment indicated that the constructed biosensor had great potential for early cancer diagnosis.

The inhibitory effect of human umbilical cord mesenchymal stem cells expressing anti-HAAH scFv-sTRAIL fusion protein on glioma

Glioma is the most common malignant intracranial tumor with low 5-year survival rate. In this study, we constructed a plasmid expressing anti-HAAH single-chain antibody and sTRAIL fusion protein (scFv-sTRAIL), and explored the effects of the double gene modified human umbilical cord mesenchyreal stem cells (hucMSCs) on the growth of glioma in vitro and in vivo. The isolated hucMSCs were identified by detecting the adipogenic differentiation ability and the osteogenic differentiation ability. The phenotypes of hucMSCs were determined by the flow cytometry. The hucMSCs were infected with lentivirus expression scFv-sTRAIL fusion protein. The expression of sTRAIL in hucMSCs were detected by immunofluorescence staining, western blot and ELISA. The tropism of hucMSCs toward U87G cells was assessed by transwell assay. The inhibitory effect of hucMSCs on U87G cells were explored by CCK8 and apoptosis assay. The xenograft tumor was established by subcutaneously injection of U87G cells into the back of mice. The hucMSCs were injected via tail veins. The inhibitory effect of hucMSCs on glioma in vivo was assessed by TUNEL assay. The hucMSCs migrated into the xenograft tumor were revealed by detecting the green fluorescent. The results showed that the scFv-sTRAIL expression did not affect the phenotypes of hucMSCs. The scFv-sTRAIL expression promoted the tropism of hucMSCs toward U87G cells, enhanced the inhibitory effect and tumor killing effect of hucMSCs on U87G cells. The in vivo study showed that hucMSCs expressing scFv-sTRAIL demonstrated significantly higher inhibitory effect and tumor killing effect than hucMSCs expressing sTRAIL. The green fluorescence intensity in the mice injected with hucMSCs expressing scFv-sTRAIL was significantly higher than that injected with hucMSCs expressing sTRAIL. These data suggested that the scFv conferred the targeting effect of hucMSCs tropism towards the xenograft tumor. In conclusion, the hucMSCs expressing scFv-sTRAIL fusion protein gained the capability to target and kill gliomas cells in vitro and in vivo. These findings shed light on a potential therapy for glioma treatment.

Advances in the Biology, Detection Techniques, and Clinical Applications of Circulating Tumor Cells

Circulating tumor cells (CTCs) play a crucial role in tumor recurrence and metastasis, and their early detection has shown remarkable benefits in clinical theranostics. However, CTCs are extremely rare, thus detecting them in the blood is very challenging. New CTC detection techniques are continuously being developed, enabling deeper analysis of CTC biology and potential clinical application. This article reviews current CTC detection techniques and their clinical application. CTCs have provided, and will continue to provide, important insights into the process of metastasis, which could lead to development of new therapies for different cancers.

The Role of Proteoglycans in Cancer Metastasis and Circulating Tumor Cell Analysis

Circulating tumor cells (CTCs) are accessible by liquid biopsies via an easy blood draw. They represent not only the primary tumor site, but also potential metastatic lesions, and could thus be an attractive supplement for cancer diagnostics. However, the analysis of rare CTCs in billions of normal blood cells is still technically challenging and novel specific CTC markers are needed. The formation of metastasis is a complex process supported by numerous molecular alterations, and thus novel CTC markers might be found by focusing on this process. One example of this is specific changes in the cancer cell glycocalyx, which is a network on the cell surface composed of carbohydrate structures. Proteoglycans are important glycocalyx components and consist of a protein core and covalently attached long glycosaminoglycan chains. A few CTC assays have already utilized proteoglycans for both enrichment and analysis of CTCs. Nonetheless, the biological function of proteoglycans on clinical CTCs has not been studied in detail so far. Therefore, the present review describes proteoglycan functions during the metastatic cascade to highlight their importance to CTCs. We also outline current approaches for CTC assays based on targeting proteoglycans by their protein cores or their glycosaminoglycan chains. Lastly, we briefly discuss important technical aspects, which should be considered for studying proteoglycans.