One-pot, one-step, label-free miRNA detection method based on the structural transition of dumbbell probe.

In this study, we present a one-pot, one-step, label-free miRNA detection method through a structural transition of a specially designed dumbbell-shape probe, initiating a rolling circle transition (RCT). In principle, target miRNA binds to right loop of the dumbbell probe (DP), which allows structural change of the DP to circular form, exposing a sequence complementary to the T7 promoter (T7p) previously hidden within the stem. This exposure allows T7 RNA polymerase to initiate RCT, producing a repetitive Mango aptamer sequence. TO1-biotin, fluorescent dye, binds to the aptamer, inducing a detectable enhancement of fluorescence intensity. Without miR-141, the DP stays closed, RCT is prevented, and the fluorescence intensity remains low. By employing this novel strategy, target miRNA was successfully identified with a detection of 73 pM and a dynamic linear range of 0-10 nM. Additionally, the method developed enables one-pot, one-step, and label-free detection of miRNA, demonstrating potential for point-of-care testing (POCT) applications. Furthermore, the practical application of the designed technique was demonstrated by reliably detecting the target miRNA in the human serum sample. We also believe that the conceived approach could be widely used to detect not only miRNAs but also diverse biomolecules by simply replacing the detection probe.

The p53-Driven Anticancer Effect of Ribes fasciculatum Extract on AGS Gastric Cancer Cells.

Cancer metastasis is directly related to the survival rate of cancer patients. Although cancer metastasis proceeds by the movement of cancer cells, it is fundamentally caused by its resistance to anoikis, a mechanism of apoptosis caused by the loss of adhesion of cancer cells. Therefore, it was found that inhibiting cancer migration and reducing anoikis resistance are important for cancer suppression, and natural compounds can effectively control it. Among them, Ribes fasciculatum, which has been used as a medicinal plant, was confirmed to have anticancer potential, and experiments were conducted to prove various anticancer effects by extracting Ribes fasciculatum (RFE). Through various experiments, it was observed that RFE induces apoptosis of AGS gastric cancer cells, arrests the cell cycle, induces oxidative stress, and reduces mobility. It was also demonstrated that anoikis resistance was attenuated through the downregulation of proteins, such as epidermal growth factor receptor (EGFR). Moreover, the anticancer effect of RFE depends upon the increase in p53 expression, suggesting that RFE is suitable for the development of p53-targeted anticancer materials. Moreover, through xenotransplantation, it was found that the anticancer effect of RFE confirmed in vitro was continued in vivo.