scholarly journals Enhanced Hybridization Selectivity Using Structured GammaPNA Probes

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 970 ◽  
Author(s):  
Taylor D. Canady ◽  
April S. Berlyoung ◽  
Joe A. Martinez ◽  
Cole Emanuelson ◽  
Cheryl A. Telmer ◽  
...  

High affinity nucleic acid analogues such as gammaPNA (γPNA) are capable of invading stable secondary and tertiary structures in DNA and RNA targets but are susceptible to off-target binding to mismatch-containing sequences. We introduced a hairpin secondary structure into a γPNA oligomer to enhance hybridization selectivity compared with a hairpin-free analogue. The hairpin structure features a five base PNA mask that covers the proximal five bases of the γPNA probe, leaving an additional five γPNA bases available as a toehold for target hybridization. Surface plasmon resonance experiments demonstrated that the hairpin probe exhibited slower on-rates and faster off-rates (i.e., lower affinity) compared with the linear probe but improved single mismatch discrimination by up to a factor of five, due primarily to slower on-rates for mismatch vs. perfect match targets. The ability to discriminate against single mismatches was also determined in a cell-free mRNA translation assay using a luciferase reporter gene, where the hairpin probe was two-fold more selective than the linear probe. These results validate the hairpin design and present a generalizable approach to improving hybridization selectivity.

Planta Medica ◽  
2017 ◽  
Vol 83 (14/15) ◽  
pp. 1242-1250 ◽  
Author(s):  
Xin Liu ◽  
Simone Latkolik ◽  
Atanas Atanasov ◽  
Olaf Kunert ◽  
Eva-Maria Pferschy-Wenzig ◽  
...  

AbstractThe roots of Bupleurum chinense have a long history in traditional medicine to treat infectious diseases and inflammatory disorders. Two major compounds, saikosaponins A and D, were reported to exert potent anti-inflammatory activity by inhibiting NF-κB. In the present study, we isolated new saikosaponin analogues from the roots of B. chinese interfering with NF-κB activity in vitro. The methanol-soluble fraction of the dichloromethane extract of Radix Bupleuri was subjected to activity-guided isolation yielding 18 compounds, including triterpenoids and polyacetylenes. Their structures were determined by spectroscopic methods as saikogenin D (1), prosaikogenin D (2), saikosaponins B2 (3), W (4), B1 (5), Y (6), D (7), A (8), E (9), B4 (10), B3 (11), and T (12), saikodiyne A (13), D (14), E (15) and F (16), falcarindiol (17), and 1-linoleoyl-sn-glycero-3-phosphorylcholine (18). Among them, 4, 15, and 16 are new compounds, whereas 6, previously described as a semi-synthetic compound, is isolated from a natural source for the first time, and 13–17 are the first reports of polyacetylenes from this plant. Nine saponins/triterpenoids were tested for inhibition of NF-κB signaling in a cell-based NF-κB-dependent luciferase reporter gene model in vitro. Five of them (1, 2, 4, 6, and 8) showed strong (> 50%, at 30 µM) NF-κB inhibition, but also varying degrees of cytotoxicity, with compounds 1 and 4 (showing no significant cytotoxicity) presenting IC50 values of 14.0 µM and 14.1 µM in the cell-based assay, respectively.


2018 ◽  
Author(s):  
Hella Baumann ◽  
Holly Matthews ◽  
Mengqiao Li ◽  
Jenny J. Hu ◽  
Keith R. Willison ◽  
...  

ABSTRACTDrugs that target protein synthesis are well-validated for use as antimicrobials, yet specific high throughput (HTP) methods to screen for those targeting malaria are lacking. Here, we have developed a cell free in vitro translation (IVT) assay for the human malaria parasite, Plasmodium falciparum, which reconstitutes the native parasite protein translation machinery. Combining clarified IVT lysate with a click beetle luciferase reporter gene fused to untranslated regions of Pf histidine-rich proteins (hrp)-2 and 3, the HTP IVT assay accurately reports protein translation in a 384-well plate format using a standard spectrofluorometer. We validate the assay as effective in detecting compounds targeting the ribosome, ribosome co-factors (elongation factor 2) and cytosolic tRNA synthetases as well as its ability to find translation inhibitors in a blind screen using a high-density assay format amenable for high throughput. This demonstrates an ability to reconstitute the breadth of the parasite eukaryotic protein translation machinery in vitro and use it as a powerful platform for antimalarial drug discovery.


2011 ◽  
Vol 76 (11) ◽  
pp. 1347-1360 ◽  
Author(s):  
Irina V. Astakhova ◽  
T. Santhosh Kumar ◽  
Jesper Wengel

Herein, a novel fluorescent nucleotide analogue, perylene-2′-amino-α-L-LNA, has been prepared and studied within synthetic oligonucleotides of different sequences. The phosphoramidite reagent was synthesized in 85% overall yield starting from 2′-amino-α-L-LNA nucleoside. Incorporation efficiency of the resulting perylene-2′-amino-α-L-LNA monomer (T*) into synthetic oligonucleotides was significantly improved by replacement of the typically used 1H-tetrazole activator with pyridine hydrochloride. Generally, oligonucleotides containing monomerT* showed high binding affinity towards complementary DNA and RNA targets, batochromically shifted excitation/emission wavelengths with respect to the often applied polyaromatic hydrocarbon pyrene, high fluorescent quantum yields and very low target detection limits (5–10 nM). Fluorescence of single stranded LNA/DNA mixmer oligonucleotide having two incorporations of monomersT* was quenched (quantum yield ΦF= 0.21) relative to duplexes of this probe with complementary DNA and RNA (ΦF= 0.42 and 0.35, respectively). On the contrary, a strong fluorescence quenching upon target binding was demonstrated by two short oligonucleotides of analogues sequences containing monomersT* at 5′- and 3′-terminal positions. We explain the hybridization-induced light-up effect observed for double-labeled probe by a reduction of fluorescence quenching due to precise positioning of the fluorophores within the double-stranded complexes. Furthermore, we propose that a covalent link between twoT* monomers in the double-labeled probe provides a remarkable degree of rigidity in the double helix which enforces positioning of the bulky perylene moieties in the nonpolar groove resulting in reduced fluorescence quenching.


1997 ◽  
Vol 251 (1) ◽  
pp. 129-132 ◽  
Author(s):  
Elizabeth R. Fairey ◽  
J.Stewart G. Edmunds ◽  
John S. Ramsdell

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
S Vogl ◽  
P Picker ◽  
N Fakhrudin ◽  
A Atanasov ◽  
E Heiß ◽  
...  

Author(s):  
Zheng Dong ◽  
Qing-Hua Xu ◽  
Yuan-Bin Zhu ◽  
Yong-Feng Wang ◽  
Jie Xiong ◽  
...  

Aims : The present study explored the clinical significance of microRNA-22 (miR-22) expression in lung squamous cell carcinoma and to explore the targeting relationship with vascular endothelial growth factor receptor 3 (VEGFR3). Methods: A total of 49 patients with lung squamous cell carcinoma who underwent surgical treatment was selected. The expression of miR-22 was detected by fluorescence quantitative real-time PCR (qPCR), the expression of VEGFR3 was detected by Western blotting assays, and D240 labeled microlymphatic vessels density (MLVD) was detected immunohistochemistry (IHC). Lung squamous cell carcinoma cell line SK-MES-1 was selected and the targeting relationship between miR-22 and VEGFR3 was analyzed by double luciferase reporter gene assay. Western blotting assays were used to detect the expression of vascular endothelial growth factor-D (VEGF-D) and D240 in the blank control group, empty vector transfection group, miR-22 transfection group, miR-22 and VEGFR3 co-transfection group. Results: The expression range of miR-22 in lung squamous cell carcinoma was 0.8-3.5. The expression of miR-22 in lung squamous cell carcinoma was significantly different by tumor maximum diameter, lymph node metastasis, vascular invasion and TNM stage. The expression of miR-22 was linked to survival time. There was a negative correlation between miR-22 and VEGFR3, miR-22 and MLVD. Double luciferase reporter gene assays showed that miR-22 reduced the luciferase activity of pGL3-VEGFR3-WT transfected cells. Compared with the control group, the expression of VEGF-D and D2-40 in the miR-22 transfection group was significantly decreased. However, VEGF-D and D240 in the miR-22 and VEGFR3 cotransfection group reversed the changes. Conclusion: We assumed that the abnormal expression of miR-22 in lung squamous cell carcinoma may be involved in the development and progression of lung squamous cell carcinoma. MiR-22 negatively regulated the target gene VEGFR3 to mediate lymphangiogenesis. The expression of miR-22 may also be linked to the prognosis of the disease.


2020 ◽  
Vol 20 (6) ◽  
pp. 715-723
Author(s):  
Natarajan Nandakumar ◽  
Pushparathinam Gopinath ◽  
Jacob Gopas ◽  
Kannoth M. Muraleedharan

Background: The authors investigated the NF-κB inhibitory role of three Benzisothiazolone (BIT) derivatives (1, 2 and 3) in Hodgkin’s Lymphoma cells (L428) which constitutively express activated NF-κB. All three compounds showed dose-dependent NF-κB inhibition (78.3, 70.7 and 34.6%) in the luciferase reporter gene assay and were found cytotoxic at IC50 values of 3.3μg/ml, 4.35μg/ml and 13.8μg/ml, respectively by the XTT assay. BIT 1and BIT 2 (but not BIT 3) suppressed both NF-κB subunits p50 and p65 in cytoplasmic and nuclear extracts in a concentration-dependent manner. Furthermore, BIT 1 showed a moderate synergistic effect with the standard chemotherapy drugs etoposide and doxorubicin, whereas BIT 2 and 3 showed a moderate additive effect to antagonistic effect. Cisplatin exhibited an antagonist effect on all the compounds tested under various concentrations, except in the case of 1.56μg/ml of BIT 3 with 0.156μg/ml of cisplatin. The compounds also inhibited the migration of adherent human lung adenocarcinoma cells (A549) in vitro. We conclude that especially BIT 1 and BIT 2 have in vitro anti-inflammatory and anti-cancer activities, which can be further investigated for future potential therapeutic use. Methods: Inspired by the electrophilic sulfur in Nuphar alkaloids, monomeric and dimeric benzisothiazolones were synthesized from dithiodibenzoic acid and their NF-κB inhibitory role was explored. NF-κB inhibition and cytotoxicity of the synthesized derivatives were studied using luciferase reporter gene assay and XTTassay. Immunocytochemistry studies were performed using L428 cells. Cell migration assay was conducted using the A549 cell line. L428 cells were used to conduct combination studies and the results were plotted using CompuSyn software. Results: Benzisothiazolone derivatives exhibited cytotoxicity in Hodgkin’s Lymphoma cells through NF-κB inhibition. Potent compounds showed suppression of both NF-κB subunits p50 and p65 in a concentrationdependent manner, both in cytoplasmic and nuclear extracts. Combination studies suggest that benzisothiazolone derivatives possess a synergistic effect with etoposide and doxorubicin. Furthermore, the compounds also inhibited the migration of A549 cells. Conclusion: Benzisothiazolones bearing one or two electrophilic sulfur atoms as part of the heterocyclic framework exhibited cytotoxicity in Hodgkin’s Lymphoma cells through NF-κB inhibition. In addition, these derivatives also exhibited a synergistic effect with etoposide and doxorubicin along with the ability to inhibit the migration of A549 cells. Our study suggests that BIT-based new chemical entities could lead to potential anticancer agents.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110093
Author(s):  
Mingxin Liu ◽  
Hong Wu ◽  
Yiqiang Liu ◽  
Yan Tan ◽  
Songtao Wang ◽  
...  

MiR-326 functions as an antioncogene in the several types of cancer. However, the underling mechanisms through which miRNA-326 regulates the anti-carcinogenesis of lung adenocarcinoma have remained elusive. The aim of this study was to explore the role and regulatory mechanism of miR-326 in cell proliferation, invasion, migration and apoptosis in lung adenocarcinoma. Quantitative real-time PCR (qRT-PCR) was used to detect the expression pattern of miR-326 in human bronchial epithelial cells (HBES-2B), 4 kinds of lung adenocarcinoma cell lines (H23, H1975, H2228, H2085) and 20 lung adenocarcinoma tissues. Then, H23 cells were infected with miR-326 mimics, miR-326 inhibitors and si-ZEB1 to build up-regulated miR-326 cell lines, down-regulated ZEB1(zinc-finger-enhancer binding protein 1)cell lines, simultaneous down-regulated ZEB1 and miR-326 cell lines. Moreover, CCK-8 assay, transwell invasion assay, wound healing assay and flow cytometry assay were employed to examine the effects of miR-326 and ZEB1 on the proliferation, invasion, migration and apoptosis abilities of H23 cells. Western blot was performed to explore the effects of miR-326 and ZEB1 on the expression of invasion and migration related proteins N-cadherin, E-cadherin, MMP7, MMP13, SLUG and apoptotic proteins PARP, BAX. On the mechanism, a dual-luciferase reporter gene was used to measure the target relationship between miR-326 and ZEB1. MiR-326 expression was significantly downregulated in lung adenocarcinoma tissues and cells. Overexpression of miR-326 significantly inhibited the malignant behaviors of H23 cells. Mechanically, luciferase reporter assay showed that ZEB1 was a direct target of miR-326. MiR-326 mimic downregulated the expression of ZEB1. Furthermore, knocking down ZEB1 strongly inhibited the proliferation, invasion and migration of H23 cells but promoted apoptosis. MiR-326 could target ZEB1 to inhibit the proliferation, invasion and migration of lung adenocarcinoma cells and promote apoptosis, which is a potential therapeutic target for lung adenocarcinoma.


2020 ◽  
Vol 15 (1) ◽  
pp. 159-172
Author(s):  
Guoning Su ◽  
Zhibing Yan ◽  
Min Deng

AbstractSevoflurane was frequently used as a volatile anesthetic in cancer surgery. However, the potential mechanism of sevoflurane on lung cancer remains largely unclear. In this study, lung cancer cell lines (H446 and H1975) were treated by various concentrations of sevoflurane. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assessment and colony formation assay were performed to detect the cell viability and proliferation, separately. Also, transwell assay or flow cytometry assay was applied as well to evaluate the invasive ability or apoptosis in lung cancer cells, respectively. Western blot assay was employed to detect the protein levels of β-catenin and Wnt5a. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the expression level of prostate cancer-associated transcript 6 (PCAT6) and miR-326 in lung cancer tissues and cells. The target interaction between miR-326 and PCAT6 or Wnt5a was predicted by bioinformatics analysis and verified by the dual-luciferase reporter gene assay. Sevoflurane inhibited the abilities on viability, proliferation, invasion, and activation of Wnt/β-catenin signaling, but promoted apoptosis of H446 and H1975 cells in a dose-dependent manner. The expression of PCAT6 was increased in lung cancer tissues and cells, except for that of miR-326. Besides, sevoflurane could lead to expressed limitation of PCAT6 or improvement of miR-326. This process presented a stepwise manner. Up-regulation of PCAT6 restored the suppression of sevoflurane on abilities of proliferation, invasion, rather than apoptosis, and re-activated the Wnt5a/β-catenin signaling in cells. Moreover, the putative binding sites between miR-326 and PCTA6 or Wnt5a were predicted by starBase v2.0 software online. PCAT6 suppressing effects on cells could be reversed by pre-treatment with miR-326 vector. The promotion of Wnt5a inverted effects led from miR-326 or sevoflurane. Our study indicated that sevoflurane inhibited the proliferation, and invasion, but enhanced the apoptosis in lung cancer cells by regulating the lncRNA PCAT6/miR-326/Wnt5a/β-catenin axis.


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