Electrochemical aptasensor detection of electron transfer flavoprotein subunit beta for leptospirosis diagnosis.

Electron transfer flavoprotein subunit beta (ETFB) of Leptospira interrogans is a biomarker for diagnosing leptospiral infection. Thus, the ETFB-specific nuclease-resistant RNA aptamer ETFB3-63 was developed and used in an electrochemical aptasensor to assay ETFB. Although the majority of reported biosensors detect various genes and antibodies of L. interrogans, this is the first attempt to construct an electrochemical biosensor to detect ETFB protein for the diagnosis of leptospiral infection. The ETFB protein can be detected without any extraction phase. In this assay, a single-stranded DNA probe complementary to the ETFB3-63 sequence was immobilized on a screen-printed carbon electrode (SPCE). The aptamer was then incubated and hybridized with the antisense probe on the SPCE. In the presence of ETFB, the aptamer dissociates from the aptamer/probe complex on the SPCE to bind with the protein. Methylene blue was then added to intercalate with the remaining hybridized aptamers, and its signal was measured using differential pulse voltammetry. The signal arising from the intercalated methylene blue decreased with increasing concentration of ETFB, showing a linear response in the range of 50-500 nM of ETFB and 10 to 109 leptospira cells per mL, respectively. The aptasensor signal was also specific to L. interrogans but not to 12 related bacteria tested. In addition, the aptasensor showed similar performance in detecting ETFB spiked in human serum to that in buffer, indicating that proteins in the serum do not interfere with the assay. Therefore, this assay has great potential to develop into a point-of-care electrochemical device that is accurate, cost-effective, and user-friendly for leptospirosis diagnosis.

PLGA nanoparticles containing α-fetoprotein siRNA induce apoptosis and enhance the cytotoxic effects of doxorubicin in human liver cancer cell line.

Hepatocellular carcinoma (HCC) is one of the most common cancers and is a leading cause of death. Delivery of therapeutic molecules, e.g., siRNA, to HCC cells could potentially be an alternative treatment for HCC. In this study, the siRNA targeting α-fetoprotein (AFP) mRNA was found to specifically induce apoptosis and significant cell death in HepG2 cells. It also enhanced the cytotoxic effects of doxorubicin by about two-fold, making it the candidate therapeutic molecule for HCC treatment. To deliver the siRNAs into HCC cells, the AFP siRNAs were loaded into the nanoparticles based on poly (lactic-co-glycolic) acid (PLGA). These nanoparticles induced apoptosis in HepG2 cells and synergistically increased the cytotoxicity of doxorubicin. In summary, the delivery of the AFP siRNA-loaded PLGA nanoparticles in combination with doxorubicin could be a very promising approach for the treatment of HCC.

Role of stratifin (14-3-3 sigma) in adenocarcinoma of gallbladder: A novel prognostic biomarker.

BACKGROUND: Gallbladder cancer (GBC) is a rare and fatal biliary tract malignancy. Genetic derangements are one of many factors that determine the prognosis of GBC. In this study, the expression of the stratifin (SFN) gene encoding 14-3-3 sigma protein, which is reported to be associated with the metastatic property of cholangiocarcinoma cells, was investigated in GBC. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded cancer (n = 37) and non-cancer control tissues (n = 14) of gallbladders from patients who underwent surgical resection from January 2006 to May 2015 were retrieved. The expression of SFN normalized with that of ACTB was determined using RT-qPCR. Multivariate analysis of factors affecting disease-free survival (DFS) and overall survival (OS) including the type of SFN expression was performed. RESULT: The average expression level of SFN in cancer was higher than that in control tissues (p = 0.002). The relative SFN expression in cancer tissue was classified as overexpression (n = 14) and control level expression (n = 23) according to the receiver operating characteristic (ROC) curves for discriminating early GBC recurrence or metastasis after surgery. The SFN overexpression group was associated with lower rates of distant metastasis and early tumor recurrence following resection. The univariate analysis demonstrated factors affecting DFS, including resection margin (p < 0.001), lymphovascular invasion (p = 0.040), perineural invasion (p = 0.046), and SFN expression (p < 0.001). The multivariate analysis revealed that the resection margin (p = 0.019) and SFN expression (P = 0.040) were independent prognostic factors of DFS. CONCLUSION: To achieve the longest survival, margin-free resection is recommended. The overexpression of SFN in GBC is associated with better prognosis, lower rates of early cancer recurrence, and distant metastasis following resection. SFN expression might be a novel prognostic biomarker in GBC treatment. Further studies to elucidate the role of SFN might unveil its clinical benefit in cancer treatment regimens.