A spectroscopic probe with FRET-ICT feature for thiophenol monitoring in real water samples.

Thiophenol (PhSH) is widely used in industry, however, it is extremely harmful to the environment and human health due to its high toxicity. In this work, we developed a new FRET-ICT-based ratiometric fluorescent and colorimetric probe (DMNP) for detecting PhSH. DMNP had an ultrahigh energy transfer efficiency (99.7%) and clear spacing of two emission peaks (133 nm). DMNP achieved a fast response to PhSH and exhibited drastic enhancement (over 2100 folds) of the fluorescence intensity ratio upon addition of PhSH. DMNP showed good linear response in the PhSH concentration ranges of 0.5-13 µM and 17.0-22.0 µM. Meanwhile, DMNP could also be applied to monitor PhSH in a variety of real water samples.

A synergetic FRET/ICT platform-based fluorescence probe for ratiometric imaging of bisulfite in lipid droplets.

A deep-red emission and lipid droplets-targeted fluorescence probe (named ZFPy) for effective bioimaging of bisulfite was developed from flavone moiety and benzoindole derivative based on intramolecular charge transfer (ICT) and Förster resonance energy transfer (FRET) platform. ZFPy displayed promising fluorescence parameters including bright deep red fluorescence (615 nm), large Stokes shift (205 nm), extended emission window gap (140 nm), high absolute fluorescence quantum yield (4.1%) and stable emission signal output. In addition, ZFPy realized ratiometric fluorescence monitoring for SO2 derivatives with low detection limit (30 nM), preferable linearity, high sensitivity and selectivity. Interestingly, dual fluorophores (i.e. the donor moiety and 1,1,2,3-tetra-substituent-1H-benzo[e]indol-3-ium iodide moiety) released the same emission band about 475 nm to enhance the emission signal when ZFPy reacted with SO2 derivatives, to the best of our knowledge, this is the first synergetic FRET/ICT platform for fluorescence probe, which might effectively offer ZFPy a high sensitivity and low detection limit in the detection of SO2 derivatives. More importantly, ZFPy could image exogenous and endogenous SO2 derivatives in living HeLa, HepG2 and L-O2 cells with good biocompatibility and photostability. ZFPy also preferred to load on lipid droplets with high Pearson's coefficient (0.95).

Kinesin family member 20B regulates tongue cancer progression by promoting cell proliferation.

Oral cancer refers to the malignant tumors that occur in the oral cavity, of which 80% are squamous cell carcinomas. The incidence of oral cancer accounts for ~5% of the incidence of systemic malignancies, with rapid progression, extensive infiltration and poor prognosis. In the present study, Kinesin family member (KIF)20B, a member of Kinesin­6 family, was identified as a potential biomarker which could promote cancer progression. A total of 82 patients were recruited and KIF20B expression levels were investigated by immunohistochemistry, and were divided into high and low groups based on the median of KIF20B expression levels. The clinicopathological features and survival­associated data of the two groups were analyzed and the results were provided as a table and by a Kaplan­Meier plot, respectively. Additionally, KIF20B was successfully silenced in two tongue cancer cell lines, CAL­27 and TCA­8113. MTT and colony formation assay were performed to determine the changes of cell proliferation in knocked down­KIF20B cell lines. In addition, proliferation­associated proteins Ki67 and PCNA were investigated, by western blotting. In animal experiments, subcutaneous tumor formation was performed with control cells and cells with knocked down KIF20B, to determine the inhibitory effect of KIF20B in vivo. Firstly, it was found that there was significantly high expression levels of KIF20B in tongue cancer patients (P<0.05). Patients with high expression of KIF20B had poorer clinicopathological results including tumor differentiation level, lymph node metastasis and clinical stages. The overall survival and relapse­free survival of high­expression group were also poor. Secondly, after successful establishment of cells with knocked down KIF20B, this resulted in a notable reduction in cell proliferation in vitro. Subsequent western blotting further confirmed that Ki67 and PCNA expression levels had a significant decline. Finally, it was demonstrated that knocking down KIF20B could inhibit tumor volume growth in vivo. In conclusion, the high level of KIF20B in oral squamous cell carcinoma was significantly associated with poor clinicopathological features and survival. KIF20B might promote cancer development through enhancing cell proliferation in vitro, and might be a potential biomarker of oral squamous cell carcinoma.