Here we report a robust and sensitive DNA nanostructure-based electrochemical (E-nanoDNA) sensor that utilizes tetrahedral DNA nanostructures (TDNs) as an interfacial probe to detect biomolecules in a single-step procedure. In this study, we have firstly demonstrated that the use of TDNs can significantly suppress electrochemical background signals compared to traditional linear DNA probes upon introduction of base mismatches in the edges of TDNs. After further optimization of the two functional strands in the TDNs, quantitative, one-step detection of DNA can be achieved in the picomolar range in less than 10 min, and directly in complex media. Moreover, the baseline drift of this biosensor can be greatly decreased even after several hours in flowing whole blood in vitro, which suggests that the sensor holds potential to be employed in live animals. Furthermore, through replacing functional strands with aptamers or other DNA elements, this E-nanoDNA sensor can be easily used to probe various analytes, broadening the application range of the proposed sensor.

Background: In order to identify miRNAs expression profiling from genome-wide screen for diagnosis of acute myocardial infarction (AMI) and angina pectoris (AP), we investigated the altered profile of serum microRNAs in AMI and AP patients at a relative early stage. Methods: Serum samples were taken from 117 AMI patients, 182 AP patients and 100 age-and gender-matched controls. An initial screening of miRNAs expression was performed by Solexa sequencing. Differential expression was validated using RT-qPCR in individuals samples, the samples were arranged in a two-phase selection and validation. Results: The Solexa sequencing results demonstrated marked upregulation of serum miRNAs in AMI patients compared with controls. RT-qPCR analysis identified a profile of six serum miRNAs (miR-1, miR-134, miR-186, miR-208, miR-223 and miR-499) as AMI biomarkers. MiR-208 and miR-499 were elevated higher in AP cases than in AMI cases. The ROC curves indicated a panel of six miRNAs has a great potential to offer sensitive and specific diagnostic tests for AMI. More especially, the panel of six miRNAs presents significantly differences between the AMI and AP cases. Conclusions: The six-miRNAs signature identified from genome-wide serum miRNA expression profiling may serves as a fingerprint for AMI and AP diagnosis.

PGC-1α, a potent transcriptional coactivator, is the major regulator of mitochondrial biogenesis and activity in the cardiac muscle. The dysregulation of PGC-1α and its target genes has been reported to be associated with congenital and acquired heart diseases. By examining myocardium samples from patients with Tetralogy of Fallot, we show here that PGC-1α expression levels are markedly increased in patients compared with healthy controls and positively correlated with the severity of cyanosis. Furthermore, hypoxia significantly induced the expression of PGC-1α and mitochondrial biogenesis in cultured cardiac myocytes. Mechanistic studies suggest that hypoxia-induced PGC-1α expression is regulated through the AMPK signaling pathway. Together, our data indicate that hypoxia can stimulate the expression of PGC-1α and mitochondrial biogenesis in the cardiac myocytes, and this process might provide a potential adaptive mechanism for cardiac myocytes to increase ATP output and minimize hypoxic damage to the heart.

Sensitive and specific biomarkers for the early detection of cervical cancer are urgently required to reduce the high morbidity and mortality of this disease. We previously demonstrated that circulating microRNAs (miRNAs) are correlated with certain types of human cancer. The aim of this study was to investigate the altered profile of serum miRNAs in cervical cancer patients in order to predict cervical cancer at a relative early stage. Serum samples were collected from 213 cervical cancer patients and 158 age‑ and ethnicity‑matched controls. An initial screening of miRNA expression was performed by Solexa sequencing. Differential expression was validated using the stem‑loop miRNA quantitative polymerase chain reaction (qPCR) assay in individual samples and the samples were arranged by two‑phase selection and validation. The Solexa sequencing results revealed 12 markedly upregulated serum miRNAs in cervical cancer patients compared with controls. The reverse transcription‑qPCR analysis identified a profile of 5 serum miRNAs (miR‑21, ‑29a, ‑25, ‑200a and ‑486‑5p) as a cervical cancer biomarker. The receiver operating characteristic curves indicated that a panel of 5 miRNAs constitutes a more sensitive and specific diagnostic test compared with any single miRNA‑based assay, the squamous cell carcinoma antigen or the carbohydrate antigen 125. More importantly, miR‑29a and miR‑200a may indicate tumor histological grade and progression stage. Therefore, a 5‑miRNA signature identified from genome‑wide serum miRNA expression profiling may serve as a fingerprint for cervical cancer diagnosis.

Serum microRNAs (miRNAs), with their remarkable stability and unique concentration profiles in patients with various diseases, are promising non‑invasive biomarkers for tumor detection. The present study investigated the altered profiles of serum microRNAs in patients with endometrioid endometrial cancer (EEC) in order to predict the malignancy of the disease at a relatively early stage. TaqMan® low‑density arrays (TDLAs) were used to perform an analysis in the initial screening phase using serum samples pooled from seven EEC patients and 20 controls. The differential expression was validated using a hydrolysis probe‑based stem‑loop quantitative reverse transcription polymerase chain reaction (qRT‑PCR) in samples taken from 26 EEC patients and 22 age‑ and gender‑matched healthy controls. The data obtained from the TLDAs demonstrated that 22 serum miRNAs were markedly upregulated in the EEC patients compared with the controls. The qRT‑PCR analysis further identified a profile of four serum miRNAs (miR‑222, miR‑223, miR‑186 and miR‑204) as a fingerprint for EEC detection. The area under the receiver operating characteristic (ROC) curve of this four‑serum miRNA signature was 0.927, which was markedly higher than that of carbohydrate antigen 125 (CA‑125; 0.673). The four‑miRNA signature identified by genome‑wide serum miRNA expression profiling analysis provides a novel, non‑invasive approach for EEC diagnosis.