Guiming Xiang

Procalcitonin sensitive detection based on graphene–gold nanocomposite film sensor platform and single-walled carbon nanohorns/hollow Pt chains complex as signal tags

Septicemia is a serious disease that requires early diagnosis, and procalcitonin (PCT) serves as a diagnostic biomarker for this disease. Traditional clinical detection (via immune-gold chips) remains difficult and expensive. An electrochemical immunosensor based on new nanomaterials may provide a solving approach. Herein, an ultrasensitive sandwich electrochemical strategy for PCT detection was developed. Firstly, reduced graphene oxide (rGO)-gold (Au) nano-composite film was used as the immunosensor platform to increase the amount of PCT antibody 1(Ab1) immobilized. Next, single-walled carbon nanohorns (SWCNHs)/hollow Pt chains (HPtCs) complex was firstly utilized to label PCT Ab2 as signal tags. For SWCNHs with few side effects, high surface area and HPtCs with higher specific surface, better catalytic activity, complex synthesized from both may provide more advantages. Moreover, to amplify signal, HPtC catalytic activity with H2O2 was enhanced by horseradish peroxidase (HRP) for dual synergy amplification. The whole results demonstrated that the proposed immunosensor exhibited fast operation, high sensitivity, good reproducibility, acceptable stability and ideal selectivity compared with traditional method. The linear calibration of the immunosensor ranged from 1.00 pg/mL to 2.00 × 10(1)ng/mL with a detection limit of 0.43 pg/mL. Analytical application results revealed that the immunosensor matched with the real concentrations of serum samples. Overall this immunosensor may provide a new alternative strategy for PCT detection.

Identification of Endogenous Controls for Analyzing Serum Exosomal miRNA in Patients with Hepatitis B or Hepatocellular Carcinoma

Serum exosomal microRNAs (miRNAs) have received considerable attention as potential biomarkers for diagnosing cancer. The canonical technique for measuring miRNA transcript levels is reverse transcription quantitative polymerase chain reaction (RT-qPCR). One prerequisite for validating RT-qPCR data is proper normalization with respect to stably expressed endogenous reference genes. However, genes that meet all of the criteria of a control gene for exosomal miRNAs have not yet been identified. To find out the control gene for exosomal miRNAs, we evaluated the expression stability of 11 well-known reference genes in circulating exosomes. In this study, we found that the combination of miR-221, miR-191, let-7a, miR-181a, and miR-26a can be an optimal gene reference set for normalizing the expression of liver-specific miRNAs. This combination enhanced the robustness of the relative quantification analyses. These findings highlight the importance of validating reference genes before quantifying target miRNAs. Furthermore, our findings will improve studies that monitor hepatitis progression and will aid in the discovery of noninvasive biomarkers to diagnose early stage HCC.

Ultrasensitive strategy based on PtPd nanodendrite/nano-flower-like@GO signal amplification for the detection of long non-coding RNA

Highly up-regulated in liver cancer (HULC) is a novel promising noninvasive biomarker for hepatocellular carcinoma (HCC), which is a kind of long non-coding RNAs (lncRNAs). But traditional methods limited HULC clinical detection for ownself drawbacks. Development a new HULC detection approach is urgent and necessary. Electrochemical nucleic acid sensor based on different signal amplification strategies with high sensitivity, fast, simple, and convenient, may solve this problem. Herein, we propose a novel strategy based on Pt-Pd bimetallic nanodendrites/nanoflower-like clusters on graphene oxide/Au/horseradish peroxidase (PtPd BND/BNF@GO/Au/HRP) to enhance the catalytic efficiency and sensitivity. And Au particles were simultaneously and separately capped with thionine or detection probe, which increase the binding amount of detection probe and decrease the electronic background. The results indicated that the catalytic effect was noticeably elevated and that the biosensor provides ultrasensitive detection for the lncRNA HULC. The linear calibration of the biosensor ranged from 1.00×10(-3) to 1.00×10(3) pM/mL, and the limit of detection was 0.247 fM/mL. The lncRNA biosensor based on the PtPd BND/BNF@GO/Au/HRP/Au/thionine exhibited acceptable reproducibility and clear selectivity. This strategy may provide a new alternative for clinical HCC diagnosis through the detection of HULC.

Hypoxia Promotes Epithelial - Mesenchymal Transition of Hepatocellular Carcinoma Cells via Inducing GLIPR-2 Expression

Glioma pathogenesis related-2 (GLIPR-2) belongs to pathogenesis related-1 (PR-1) family whose function remains unknown. In our previous studies, GLIPR-2 was found to be a novel potent stimulator of epithelial-to-mesenchymal transition (EMT) in renal fibrosis which has been classified as type 2 EMT. However, whether GLIPR-2 could induce type 3 EMT in carcinogenesis needs further investigation. In this study, we showed that GLIPR-2 was expressed in hepatocellular carcinoma (HCC) tissues, hypoxia could upregulate the expression of GLIPR-2 in HepG2 and PLC/PRF/5 cells in vitro, overexpression of this protein promoted migration and invasion via EMT, knockdown of GLIPR-2 attenuated migration and invasion of HepG2 and PLC/PRF/5 cells in hypoxia. Moreover, extracellular signal-regulated kinases 1 and 2 (ERK1/2) are positively regulated by GLIPR-2. Taken together, we provide evidence for a hypoxia/GLIPR-2/EMT/migration and invasion axis in HCC cells and it provides novel insights into the mechanism of migration and invasion of hepatocellular carcinoma cells in hypoxia condition.

Development of a real-time resistance measurement for Vibrio parahaemolyticus detection by the lecithin-dependent hemolysin gene.

The marine bacterium Vibrio parahaemolyticus (V. parahaemolyticus) causes gastroenteritis in humans via the ingestion of raw or undercooked contaminated seafood, and early diagnosis and prompt treatment are important for the prevention of V. parahaemolyticus-related diseases. In this study, a real-time resistance measurement based on loop-mediated isothermal amplification (LAMP), electrochemical ion bonding (Crystal violet and Mg2+), real-time monitoring, and derivative analysis was developed. V. parahaemolyticus DNA was first amplified by LAMP, and the products (DNA and pyrophosphate) represented two types of negative ions that could combine with a positive dye (Crystal violet) and positive ions (Mg2+) to increase the resistance of the reaction liquid. This resistance was measured in real-time using a specially designed resistance electrode, thus permitting the quantitative detection of V. parahaemolyticus. The results were obtained in 1–2 hours, with a minimum bacterial density of 10 CFU.mL−1 and high levels of accuracy (97%), sensitivity (96.08%), and specificity (97.96%) when compared to cultivation methods. Therefore, this simple and rapid method has a potential application in the detection of V. parahaemolyticus on a gene chip or in point-of-care testing.

A novel strategy of procalcitonin detection based on multi-nanomaterials of single-walled carbon nanohorns–hollow Pt nanospheres/PAMAM as signal tags

Procalcitonin (PCT) is a common clinical biomarker of septicemia, and precise detection of PCT is critical to the treatment of septicemia. Conventional detection methods suffer various shortcomings that hinder precise PCT detection. An electrochemical immunosensor based on the antigen–antibody immune-reaction may provide a solution. We developed a novel electrochemical immunosensor for PCT using single-walled carbon nanohorns (SWCNHs)–hollow Pt nanospheres (HPtNPs) as signal tags. Given the high specific surface area of SWCNHs and the interesting catalytic properties of HPtNPs, the successful synthesis of SWCNHs–HPtNPs provided not only a high specific surface area for loading substantial antigen but also good catalytic properties to enhance the electrochemical signal with high sensitivity. In addition, to increase the quantity of the electrochemically active compound thionine immobilized on the surface, PAMAM, which is a class of hyper-branched polymers with a diamine core and an amido amine branching structure, was assembled on the SWCNH–HPtNP surface. A series of results demonstrated the higher sensitivity, improved stability and ideal selectivity of the novel immunosensor compared with a sensor prepared using traditional methods. Furthermore, a broad linear response from 10 pg mL−1 to 20 ng mL−1 with a detection limit of 1.74 pg mL−1 was observed under the optimized conditions of the assay. This immunosensor may provide a new option for clinical septicemia diagnosis through PCT detection.

A novel label free long non-coding RNA electrochemical biosensor based on green L-cysteine electrodeposition and Au–Rh hollow nanospheres as tags

Nuclear paraspeckle assembly transcript 1 (NEAT1) that reflects whether the bodys anti-HIV virus immunity is strong or weak is one of many long non-coding RNAs (lncRNAs). The effective detection of NEAT1 has great scientific significance and clinical value. However, the detection of lncRNA is difficult with existing methods. The quantification of lncRNA by electrochemical methods based on changes in circuit properties such as capacitance, conductance and resistance may solve this problem. In this study, we describe a new label-free strategy based on catalytic signal amplification with single-wall carbon nanotubes wrapped with Au–Rh hollow nanospheres (Au/Rh-HNP@SWCNT). This strategy is useful for detecting the lncRNA NEAT1. Firstly, L-cysteine (L-Cys) was electrodeposited onto a Au electrode and incubated in colloidal Au to fully expose all of the binding sites of the Au particles, which can bind to L-Cys through its thiol-group. It can take advantage of each surface of the Au nanoparticles that is bound to the capture probe, which contains a (GGG)3 trimer that can bind to the electron mediator hemin. The results indicate that catalysis was noticeably enhanced and that the biosensor provided ultrasensitive detection of the lncRNA NEAT1. The linear calibration of the biosensor ranged from 1 fM mL−1 to 100 nM mL−1, and the limit of detection was 0.8863 fM mL−1. This lncRNA biosensor based on Au/Rh-HNP@SWCNT complex signal amplification and an L-Cys Au nano-film exhibited acceptable reproducibility and clear selectivity. This strategy may provide a new alternative for clinical HIV diagnosis through the detection of NEAT1.

Common functional polymorphism within miR-146a and miR-196a-2 as susceptibility loci for hepatocellular carcinoma: An updated meta-analysis.

Background Mutations or single nucleotide polymorphisms (SNPs) within the gene region of microRNAs play an important role for the development of hepatocellular carcinoma (HCC). Extensive studies have tried to investigate the susceptibility role of miR-146a rs2819164 and miR-196a-2 rs11614913. However, these results are still inconsistent and inconclusive. We undertook a meta-analysis containing primarily Asian studies to assess the associations of the two SNPs with HCC risk. Methods 19 studies including miR-146a (7170 cases and 9443 controls) and 15 studies including miR-196a-2 (6417 cases and 7627 controls) were used for meta-analysis. Odds ratios and 95% CI were calculated to assess the association in five different genetic models. Results For the rs2910164 polymorphism of miR-146a, significantly increased risks for HCC were observed when all studies were pooled under two models (CG vs CC: OR = 1.11, 95% CI = 1.02–1.21, P = 0.021; GG + CG vs CC: OR = 1.11, 95% CI = 1.01–1.22, P = 0.035). For the rs11614913 polymorphism of miR-196a-2, significant increased risks for HCC development were observed when all studies were pooled under four models (C vs T: OR = 1.14, 95% CI = 1.06–1.23, P = 0.001; CC vs TT: OR = 1.31, 95% CI = 1.12–1.53, P = 0.001; CC + TC vs TT: OR = 1.16, 95% CI = 1.03–1.31, P = 0.018; CC vs TC + TT: OR = 1.14, 95% CI = 1.00–1.30, P = 0.043). Conclusion Our results show that the two common SNPs within the miRNAs were associated with modest increased risk of HCC (OR < 1.6), especially in the Asian population. Larger population-based studies validating these results are needed.

Expression of hPOT1 in HeLa Cells and the Probability of Gene Variation of hpot1 Exon14 in Endometrial Cancer are Much Higher than in Other Cancers

To investigate the expression of hPOT1 in the HeLa cell line and screen point mutations of hpot1 in different tumor tissues a two step osmotic method was used to extract nuclear proteins. EMSA was performed to determine the expression of hPOT1 in the HeLa cell line. PCR was also employed to amplify the exon14 sequence of the hpot1 gene in various of cancer tissues. A SV gel and PCR clean-up system was performed to enrich PCR products. DNAStar was used to analyse the exon14 sequence of the hpot1 gene. hPOT1 was expressed in the HeLa cell line and the signal was gradually enhanced as the amount of extracted nuclear proteins increased. The DNA fragment of exon14 of hpot1 was successfully amplified in the HeLa cell line and all cancer tissues, point mutations being observed in 2 out of 3 cases of endometrial cancer (66.7%) despite the hpot1 sequence being highly conserved. However, the sequence of hpot1 exon14 do not demonstrate point mutations in most cancer tissues. Since hPOT1 was expressed in HeLa cell and the probability of gene point variants was obviously higher in endometrial cancer than other cancers, it may be involved in the pathogenesis of gynecological cancers, especially in cervix and endometrium.