Identification of immune-associated biomarker for predicting lung adenocarcinoma: bioinformatics analysis and experiment verification of PTK6.

BACKGROUND: Abnormal expression of protein tyrosine kinase 6 (PTK6) has been proven to be involved in the development of gynecological tumors. However, its immune-related carcinogenic mechanism in other tumors remains unclear. OBJECTIVE: The aim of this study was to identify PTK6 as a novel prognostic biomarker in pan-cancer, especially in lung adenocarcinoma (LUAD), which is correlated with immune infiltration, and to clarify its clinicopathological and prognostic significance. METHODS: The prognostic value and immune relevance of PTK6 were investigated by using bio-informatics in this study. PTK6 expression was validated in vitro experiments (lung cancer cell lines PC9, NCI-H1975, and HCC827; human normal lung epithelial cells BEAS-2B). Western blot (WB) revealed the PTK6 protein expression in lung cancer cell lines. PTK6 expression was inhibited by Tilfrinib. Colony formation and the Cell Counting Kit-8 (CCK-8) assay were used to detect cell proliferation. The wound healing and trans-well were performed to analyze the cell migration capacity. Then flow cytometry was conducted to evaluate the cell apoptosis. Eventually, the relationship between PTK6 and immune checkpoints was examined. WB was used to estimate the PD-L1 expression at different Tilfrinib doses. RESULTS: PTK6 was an independent predictive factor for LUAD and was substantially expressed in LUAD. Pathological stage was significantly correlated with increased PTK6 expression. In accordance with survival analysis, poor survival rate in LUAD was associated with a high expression level of PTK6. Functional enrichment of the cell cycle and TGF-ß signaling pathway was demonstrated by KEGG and GSEA analysis. Moreover, PTK6 expression considerably associated with immune infiltration in LUAD, as determined by immune analysis. Thus, the result of vitro experiments indicated that cell proliferation and migration were inhibited by the elimination of PTK6. Additionally, PTK6 suppression induced cell apoptosis. Obviously, PD-L1 protein expression level up-regulated while PTK6 was suppressed. CONCLUSION: PTK6 has predictive value for LUAD prognosis, and could up regulated PD-L1.

Identification of 2,2',4,5,5'-Pentachlorobiphenyl (PCB101) metabolites and their transmission characteristics in silver crucian carp (Carassius auratus gibelio).

Polychlorinated biphenyls (PCBs) have been attracting global concern due to their persistence and toxicity. However, the study on the metabolites of PCBs in freshwater fish is limited. In this study, the metabolites of 2,2',4,5,5'-Pentachlorobiphenyl (PCB101) in silver crucian carp (Carassius auratus gibelio) were identified for the first time. After intraperitoneal injection of PCB101 (2 mg/kg), the results showed that it could be metabolized to at least three types of metabolites, including hydroxylated (OH-), methoxylated (MeO-) and methyl sulfonated (MeSO2-) PCB101. The OH- metabolites identified in most tissues were 3-OH-PCB101and 4-OH-PCB101, such as liver, gallbladder, blood and muscle. MeSO2- metabolites identified in gallbladder, blood and brain were 3-MeSO2-PCB101 and 4-MeSO2-PCB101. Meanwhile, the MeO- metabolite identified in liver, gallbladder, blood and spleen of silver crucian carp was 4-MeO-PCB101. The investigation of the types and structures of PCB101 and its metabolites, as well as the tissue distribution and accumulation characteristics in silver crucian carp are beneficial to understand the transformation and metabolic mechanisms of PCBs in aquatic organisms. It is of great significance to identify potential pollution hazards of precursor compounds and their metabolites on aquatic products and ensure the quality and safety of aquatic products.

Two-photon-excited tumor cell fluorescence targeted imaging based on transferrin-functionalized silicon nanoparticles.

Transferrin-functionalized silicon nanoparticles (Trf-SiNPs) were fabricated and utilized for targeted fluorescence imaging in tumor cells. Silicon nanoparticles (SiNPs) was firstly synthesized by microwave irradiation method, and then coupled with transferrin in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The structural informations of Trf-SiNPs were measured by transmission electron microscope and Fourier transform infrared spectrometer. The optical properties of Trf-SiNPs were characterized by ultraviolet absorption spectrum, fluorescence emission spectrum, fluorescence quantum yield, fluorescence lifetime, photo-stability, and so on. MTT assay evidenced the low toxicity of Trf-SiNPs. Finally, Trf-SiNPs were successfully applied in HeLa cells and HepG2 cells for targeted fluorescence imaging under single-photon excitation and two-photon excitation.

Determination of Fe(â ¢) ion and cellular bioimaging based on a novel photoluminescent silicon nanoparticles.

The determination approaches of Fe (Ⅲ) in biological samples were developed by a novel water-soluble silicon nanoparticles (SiNPs). The SiNPs were synthesized by a facile microwave-assisted method, and simultaneously featured strong blue fluorescence (photoluminescence quantum yield: 25.2%), long lifetime (~13.29 ns) and good photo-stability. The fluorescence intensities of SiNPs were gradually quenched with Fe (Ⅲ) concentration increasing from 2.0 to 50 µmol/L. The detection limit of the established method was 0.56 µmol/L and the precision for eleven replicate detections of 20 µmol/L Fe (Ⅲ) was 3.2% (relative standard deviation, RSD). The spiked recoveries were 99.0%-104.5%. Results of the lifetime decay and cyclic voltammetry (CV) evidenced that the electron transfer was responsible for the fluorescence quenching mechanism of SiNPs and Fe (Ⅲ). Moreover, the SiNPs were successfully applied in the determination of Fe(Ⅲ) in different environmental waters and human serum. Finally, the resulting SiNPs exhibited the green fluorescence in HeLa cells as the optical probe.

Dehydrogenation of methylcyclohexane over Pt-based catalysts supported on functional granular activated carbon.

Herein, we developed the dehydrogenation of methylcyclohexane over Pt-based catalysts supported on functional granular activated carbon. Sulphuric acid, hydrogen peroxide, nitric acid and aminopropyl triethoxy silane were adopted to modify the granular activated carbon. The structural characterizations suggested that the carbon materials had a large surface area, abundant pore structure, and a high number of oxygen-containing functional groups, which influenced the Pt-based catalysts on the particle size, dispersion and dehydrogenation activity. The hydrogen temperature-programmed reduction technique was utilized to investigate the interaction between the active component Pt and the various functionalized granular activated carbon materials. The CO pulse technique revealed the particle sizes and dispersion of the as-prepared Pt-based catalysts. Finally, the Pt-based catalysts were successfully applied to study their catalytic activity in the dehydrogenation reaction of methylcyclohexane. The results showed that the Pt-based catalyst over granular activated carbon functionalized with sulphuric acid groups had a higher conversion of methylcyclohexane (63%) and a larger hydrogen evolution rate (741.1 mmol gPt -1 min-1) than the other resulting Pt-based catalysts at 300 °C.

Silicon nanoparticles coated with an epitope-imprinted polymer for fluorometric determination of cytochrome c.

The authors describe a composite consisting of silicon nanoparticles that were first coated with SiO2 and then with a molecularly imprinted polymer (SiNP@SiO2@MIP). The MIP was generated by dual epitope imprinting such that it can recognize cytochrome c (Cyt c). The MIP on the NPs was prepared from the functional monomer zinc(II) acrylate (ZnA), the crosslinker ethylene glycol dimethacrylate and the initiator 2,2'-azoisobutyronitrile. Dual epitope templates for Cyt c included (a) a C-terminal nonapeptide (AYLKKATNE), and (b) an N-terminal nonapeptide (GDVEKGKKI). The chelation between Zn(II) of ZnA and the amino groups or hydroxy groups of the template nonapeptides warrants good recognition and capture of Cyt c. The fluorescence originating from SiNPs has excitation/emission peaks at 360/480 nm and is quenched by Cyt c in the 0.50-40.0 µM concentration range. The correlation coefficient for the calibration plot of the imprinted NPs is 0.9937. The detection limit is 0.32 ± 0.01 µM, the precisions of six replicate detections at levels of 0.5, 20 and 40 µM Cyt c are 3.2, 2.7 and 2.8%, respectively, and the imprinting factor is 2.43. Compared to single epitope template imprinting, dual epitope imprinting results in improved selectivity. The imprinted nanoparticles can discriminate Cyt c even if one amino acid is mismatched. The method was applied to the determination of Cyt c in spiked diluted human serum and gave recoveries between 94.0 and 107.5%. Graphical Abstract A fluorescent material of the architecture silicon nanoparticle@SiO2@molecularly imprinted polymer (SiNP@SiO2@MIP) was fabricated by dual epitope imprinting and a metal-chelating method. The chelation between Zn(II) of the functional monomer zinc(II) acrylate and the amino groups or hydroxy groups of template warrants that the material recognizes and captures cytochrome c well, and this results in fluorescence quenching.

One-Pot Microwave Synthesis of Water-Dispersible, High Fluorescence Silicon Nanoparticles and Their Imaging Applications in Vitro and in Vivo.

Silicon nanoparticles (SiNPs) have been reported to be synthesized by microwave-assisted methods under high pressure. However, there is still a lack of knowledge about the synthesis of SiNPs via microwave-assisted methods under normal pressure. Here we developed a new, facile, one-pot microwave-assisted method for the synthesis SiNPs (∼4.2 nm) with excellent water solubility under normal pressure by employing glycerol as the solvent. Furthermore, glycerol might be responsible for the photoluminescence quantum yield (PLQY) value up to 47% for the resultant SiNPs. The use of organic solvent could afford less nanoparticle surface defects compared with those prepared in aqueous solution, thus improving the fluorescent efficiency. The as-prepared SiNPs simultaneously featured bright blue-green fluorescence, long lifetime (∼12.8 ns), obvious up-conversion luminescence originating from two-photon absorption, superbly strong photostability, and favorable low toxicity. As a satisfactory probe, the as-synthesized SiNPs were successfully applied in fluorescence imaging of human cervical carcinoma cell lines (HeLa) and zebrafish.

Effects of stromal interacting molecule 1 gene silencing by short hairpin RNA on the biological behavior of human gastric cancer cells.

Gastric cancer is one of the most common types of cancer worldwide. It has been reported that stromal interacting molecule 1 (STIM1) is associated with tumor progression and metastatic spread, including in cervical cancer, breast carcinoma and prostatic cancer. The present study investigated whether STIM1, an endoplasmic reticulum Ca(2+) sensor and activator of store-operated channel entry, contributed to SGC7901 cell progression. The pGPU6-shSTIM1 recombinant plasmid was constructed, and the effects of downregulation of STIM1 on the proliferation, apoptosis, migration and invasion of SGC7901 cells were examined. Western blot analysis revealed that transfection with the pGPU6-shSTIM1 plasmid successfully inhibited the expression of STIM1. STIM1 silencing in the gastric cancer cells significantly inhibited cell proliferation by arresting the cell cycle at the G0/G1 phase, and increasing the apoptotic rate following treatment of the SGC7901 cells with pGPU6-shSTIM1, indicated using an MTT cell viability assay and flow cytometery, respectively. As expected, STIM1 knock down also reduced the migration and invasion of the SGC7901 cells, demonstrated using a Transwell assay. The possible molecular mechanism involved the regulation of several signaling pathways involved in the biological behavior of cell survival, apoptosis, migration and metastasis. Together, these finding suggested that the expression of STIM1 is crucial for the proliferation and invasion of SGC7901 cells, providing a foundation for the development of novel type­specific diagnostic strategies and treatments for gastric cancer.