排序方式: 共有114条查询结果,搜索用时 0 毫秒
91.
92.
We present a molecular beacon-based electrochemical biosensor with high sensitivity and specificity for the detection of microRNA-21. A special oligonucleotide probe was prepared containing a nucleotide sequence complementary to miR-21 and consecutively linking eight and six thymines to the 3′ and 5′ ends, respectively, to allow the formation of a T-Hg2+-T complex-based molecular beacon on the electrode surface by the selective binding of Hg2+ ions. The introduction of multiple thymines at the end of the probe avoids base overlapping between the miRNA sequence and the molecular beacon formation sequence, enabling a universal probe design that can detect all types of miRNAs. A ferrocene moiety was attached to the 5′-end of the specially designed probe as an electrochemical signal indicator. The molecular beacons are formed by six consecutive T-Hg2+-T pairs by Hg2+ addition, and the molecular beacons are destroyed by perfect hybridization between 22 bases as a result of miR-21 addition. Based on this detection mechanism, we were able to detect miR-21 with LODs of 0.64 pM and 1.08 pM in buffer solution and human serum, respectively. In addition, the specifically designed oligonucleotide probe showed perfect specificity in detecting only miR-21 without binding to other miRNAs. Finally, the sensor showed excellent miR-21 recovery ability from samples spiked into serum, indicating that the method described in this study worked perfectly, even in a turbid complex matrix such as human serum. 相似文献
93.
Xiaohui Lu Wenjiao Fan Qinya Feng Yan Qi Prof. Dr. Chenghui Liu Prof. Dr. Zhengping Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(7):1701-1705
Plant microRNAs (miRNAs) are naturally 2′-O-methylated at the 3′-terminal; as a consequence, they cannot be efficiently detected by traditional target-triggered polymerization reactions. Here, a simple but robust enzyme-free sensing strategy was developed for plant miRNA analysis by using dynamic light scattering (DLS) to monitor the crosslinking of gold nanoparticles (AuNPs) amplified by click chemical ligation. Combining the enzyme-free cycling chemical-ligation-mediated signal amplification, and the intrinsic outstanding ability of DLS for discriminating the extremely low level of particle aggregation in a large pool of monodisperse AuNPs, high sensitivity was achieved and as low as 78.6 fm plant miRNA could be easily detected. 相似文献
94.
Kayo Horie Naoki Nanashima Yoshihito Yokoyama Haruhiko Yoshioka Jun Watanabe 《Molecules (Basel, Switzerland)》2022,27(12)
Ovarian cancer is the most common cause of gynecological malignancy-related mortality since early-stage disease is difficult to diagnose. Advanced clear cell carcinoma of the ovary (CCCO) has dismal prognosis, and its incidence has been increasing in Japan, emphasizing the need for highly sensitive diagnostic and prognostic CCCO biomarkers. Exosomal microRNAs (miRNAs) secreted by tumor cells are known to play a role in carcinogenesis; however, their involvement in ovarian cancer is unclear. In this study, we performed expression profiling of miRNAs from exosomes released by five cell lines representing different histological types of ovarian cancer. Exosomes isolated from culture media of cancer and normal cells were compared for miRNA composition using human miRNA microarray. We detected 143 exosomal miRNAs, whose expression was ≥1.5-fold higher in ovarian cancer cells than in the control. Among them, 28 miRNAs were upregulated in cells of all histological ovarian cancer types compared to control, and three were upregulated in CCCO cells compared to other types. Functional analyses indicated that miR-21 overexpressed in CCCO cells targeted tumor suppressor genes PTEN, TPM1, PDCD4, and MASP1. The identified miRNAs could represent novel candidate biomarkers to diagnose or monitor progression of ovarian cancer, particularly CCCO. 相似文献
95.
Some human mature microRNAs are featured of G≥2NxG≥2NyG≥2NzG≥2 sequences. In this study, a human mature microRNA, miR-5196-5p, was selected as an example to probe the secondary structure of G-rich microRNA. Our results have confirmed that miR-5196-5p could form a stable G-quadruplex structure with three G-quartets and three double-chain-reversal loops by electrospray ionization mass spectrometry, nuclear magnetic resonance, circular dichroism spectroscopy, and molecular dynamics simulation. Our study showed the prevalence of G-rich microRNAs in Homo sapiens, rat, mouse, and Arabidopsis thaliana, and they have great potential to fold into intramolecular G-quadruplexes which may serve as new targets for the regulatory function of G-rich mature microRNAs. 相似文献
96.
97.
The ultrasensitive detection of microRNAs (miRNAs) is currently pursued for the diagnosis of diseases. Due to its outstanding sensitivity, electrochemiluminescence (ECL) is expected to be very effective toward the above goal. In this short review, bioanalytical strategies currently employed in ECL detections of miRNAs are summarized. ECL sensors based on electrochemiluminescent resonance energy transfer (ERET), hybridization chain reaction (HCR), strand displacement reaction (SDR), and other strategies, have an extremely low detection limit of 10?18 M miRNA. In particular, the establishment of miniaturized ECL sensors has shown great potential for point-of-need testing of diseases. 相似文献
98.
99.
100.
Marta Kutwin Malwina Ewa Sosnowska Barbara Strojny-Cielak Slawomir Jaworski Maciej Trzaskowski Mateusz Wierzbicki Andre Chwalibog Ewa Sawosz 《Molecules (Basel, Switzerland)》2021,26(19)
Glioblastoma (GBM) is the most common primary and aggressive tumour in brain cancer. Novel therapies, despite achievements in chemotherapy, radiation and surgical techniques, are needed to improve the treatment of GBM tumours and extend patients’ survival. Gene delivery therapy mostly uses the viral vector, which causes serious adverse events in gene therapy. Graphene-based complexes can reduce the potential side effect of viral carries, with high efficiency of microRNA (miRNA) or antisense miRNA delivery to GBM cells. The objective of this study was to use graphene-based complexes to induce deregulation of miRNA level in GBM cancer cells and to regulate the selected gene expression involved in apoptosis. The complexes were characterised by Fourier transform infrared spectroscopy (FTIR), scanning transmission electron microscopy and zeta potential. The efficiency of miRNA delivery to the cancer cells was analysed by flow cytometry. The effect of the anticancer activity of graphene-based complexes functionalised by the miRNA sequence was analysed using 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxyanilide salt (XTT) assays at the gene expression level. The results partly explain the mechanisms of miRNA deregulation stress, which is affected by graphene-based complexes together with the forced transport of mimic miR-124, miR-137 and antisense miR-21, -221 and -222 as an anticancer supportive therapy. 相似文献