Structure and function encoding of a bidirectional activatable synergetic DNA machine for speeded and ultrasensitive determination of microRNAs.

This work describes the unique design of a bidirectional activatable synergetic DNA machine (BAS-DNA machine) for speeded and ultrasensitive determination of microRNA-21 (miR-21), a well-known biomarker for biomedical research and early diagnosis of lung cancer. The BAS-DNA machine is composed by a pair of track strands (Track 1 and Track 2) encoding with two regions in the opposite direction for miR-21 recognition. Introduction of miR-21 can hybridize either with Track 1 or with Track 2 to activate the BAS-DNA machine with a synergistic effect for speeded amplifying the fluorescence signal. Moreover, compared with common DNA machine with only one switch for exogenous target recognition, the BAS-DNA machine with two switches for miR-21 binding allows the speeded and strong operation of the autonomous strand scission, replication, and displacement on Track 1 and Track 2 simultaneously. This behavior makes the BAS-DNA machine powerful for ultrasensitive, specific, and fast screening of miR-21 even from real biological samples, and the fluorescence signal was found to be linear from 1 pM to 10 nM with a detection limit of 703.6 fM. We envision this BAS-DNA machine with its superior assay performance will provide a new avenue for simple, sensitive, and affordable biomedical assays.

Comparison of Talaromyces marneffei Infection in Human Immunodeficiency Virus-positive and Human Immunodeficiency Virus-negative Patients from Fujian, China.

BACKGROUND: Talaromyces (Penicillium) marneffei (TM) is an emerging dimorphic human pathogenic fungus that is endemic to Southeast Asia. TM mostly occurs as an opportunistic infection in patients with human immunodeficiency virus (HIV). The objective of this study was to compare the clinical and laboratory parameters of patients with TM infections who were HIV-positive and HIV-negative and to assess therapies and outcomes. METHODS: This was a retrospective analysis of 26 patients diagnosed with disseminated TM infection from September 2005 to April 2014 at Fujian Provincial Hospital, China. RESULTS: Patients with TM infection tend to present with fever, weight loss, and anemia. The time from symptom onset to confirmed diagnosis was greater for HIV-negative patients (n = 7; median: 60 days, range: 14-365 days) than for HIV-positive patients (n = 19; median: 30 days, range: 3-90 days, Mann-Whitney U = 31.50, P= 0.041). HIV-negative patients were more likely to have dyspnea (57.1% vs. 5.3%, χ2 = 8.86, P= 0.010), low neutrophil count (Mann-Whitney U = 27.00, P= 0.029), high CD4 count (Mann-Whitney U = 0.00, P= 0.009), and high lymphocyte count (Mann-Whitney U = 21.00, P= 0.009). There were no significant differences in other demographic, clinical, or biochemical characteristics. Among all the patients, 12 HIV-positive patient and 1 HIV-negative patient received amphotericin and fluconazole treatment, 9 of whom improved, 1 died, 2 had kidney damage, 1 had hypokalemia due to exceeded doses. CONCLUSIONS: HIV-negative patients with TM infections tend to have a longer diagnostic interval, a higher percentage of dyspnea, higher levels of CD4 and lymphocytes, and lower neutrophil counts than TM infection in HIV-positive patients. Treatment programs with amphotericin and fluconazole are mostly effective.

Silencing of Livin inhibits tumorigenesis and metastasis via VEGF and MMPs pathway in lung cancer.

Livin, an inhibitor of apoptosis protein (IAP), is overexpressed in various cancers and decreases tumor sensitivity to chemotherapy and radiotherapy. However, the effect of Livin on lung adenocarcinoma metastasis and the specific mechanism involved remain unclear. RNAi technology was used to stably silence Livin in A549 cells in the present study. The effect of Livin on tumor growth and invasion was investigated in lung cancer cells in vitro and animal models were established to determine the anti-metastasis ability of Livin silencing in vivo. The results indicated that Livin knock-down suppressed cell proliferation and inhibited cell invasion, accompanied by downregulation of VEGF and MMP-2/-9. Silencing of Livin resulted in the prevention of xenograft tumor formation. Seventy-five immunodeficient male BALB/C nude mice were randomly divided into three groups, the relative ratio of the areas with pulmonary nodules in the experimental group decreased from 46.71±7.27% to 11.07±2.94% compared with the negative control group (P<0.001), indicating the interaction between Livin, VEGF and MMPs. The xenograft tumor model of intravenous injection of tumor cells were successfully established and applied for the analysis of lung cancer tumorigenesis and metastasis in a time-dependent manner for the first time. Based on the reliable and reproducible animal model, our findings indicate that knock-down of Livin inhibits cell growth and invasion through blockade of the VEGF and MMPs pathways in lung cancer cells in vitro, and inhibits tumorigenesis and metastasis of lung cancer in vivo, suggesting that Livin is a promising antitumor target.