Discovery of Dehydroabietylamine Derivatives as Antibacterial and Antifungal Agents.

A diverse array of biologically active derivatives was derived by modifying the chemically active sites of dehydroabietylamine. Herein, we describe the synthesis of a new series of C-19-arylated dehydroabietylamine derivatives using a palladium-catalyzed C(sp3)-H activation reaction. Five analogues (3b, 3d, 3h, 3n, and 4a) exhibited antibacterial activity against Escherichia coli. Compound 4a exhibited strong inhibitory activity against DNA Topo II and Topo IV. Molecular docking modeling indicated that it can bind effectively to the target through interactions with amino acid residues. The synthesized compounds were tested in vitro for their antifungal activity against six common phytopathogenic fungi. The mechanism of action of compound 4c against Rhizoctorzia solani was investigated, revealing that it disrupts the morphology of the mycelium and enhances cell membrane permeability.

Novel Coumarin 7-Carboxamide/Sulfonamide Derivatives as Potential Fungicidal Agents: Design, Synthesis, and Biological Evaluation.

Coumarin compounds have a variety of biological activities such as anti-tumor, anti-coagulation, anti-HIV, anti-fungal, and insecticidal. Amide and sulfonamide compounds have been used as fungicides for half a century, and dozens of varieties have been developed so far. This study focused on the introduction of carboxamide and sulfonamide moieties in a coumarin core to discover novel derivatives. Based on this strategy, we synthesized two series of novel carboxamide and sulfonamide substituted coumarin derivatives, and their fungicidal activity was also investigated. Some designed compounds possessed potential activities against six phytopathogenic fungi in the primary assays, highlighted by compound 6r. Compound 6r exhibited stronger fungicidal activity against Botrytis cinerea (EC50 = 20.52 µg/mL) and will be the lead structure for further study.

Effect of the acid suppressor omeprazole on the proliferation, migration, invasion and cell cycle of esophageal squamous cell carcinoma cells via the aryl hydrocarbon receptor pathway.

Esophageal cancer is a malignant tumor type with one of the highest mortality rates worldwide. The aryl hydrocarbon receptor (AHR), which has been investigated in recent years, has been confirmed to be associated with the occurrence and development of esophageal cancer. AHR has a variety of different ligands, which regulate its activity following binding. The widely known acid inhibitor omeprazole (OME) also affects AHR and its downstream proteins (such as the cytochrome P450 family) by non-ligand binding; however, the mechanisms have remained to be fully elucidated. Therefore, the aim of the present study was to investigate the role of OME in esophageal squamous cell carcinoma (ESCC), whether the mechanism proceeds via the AHR pathway and how OME regulates AHR to affect the occurrence and development of esophageal carcinoma. The AHR-selective regulator OME was used to treat the ESCC cell lines TE1 and KYSE150. Western blot analysis was used to verify the effect of OME on AHR and proliferating cell nuclear antigen (PCNA) protein expression levels, while Cell Counting Kit (CCK)-8, wound-healing and Transwell assays were used to determine the proliferation, migration and invasion of the ESCCs, respectively, following treatment with OME. In addition, flow cytometry was used to investigate the cell cycle distribution of the ESCCs following incubation with OME. AHR was highly expressed in the ESCCs and following treatment with OME, the protein expression levels of AHR and PCNA were downregulated. The CCK-8 assay indicated that the proliferation of the ESCCs was also reduced following treatment with OME. Furthermore, flow cytometry revealed a notable block of the cells in G1/G0 phase, while the results of the wound-healing and Transwell assays respectively suggested that cell migration and invasion were reduced. In conclusion, OME inhibited the proliferation, migration and invasion of ESCC cells and blocked the cell cycle via the AHR pathway, which may provide a therapeutic effect on esophageal squamous cell cancer.

Novel Fluorinated 7-Hydroxycoumarin Derivatives Containing an Oxime Ether Moiety: Design, Synthesis, Crystal Structure and Biological Evaluation.

A series of fluorinated 7-hydroxycoumarin derivatives containing an oxime ether moiety have been designed, synthesized and evaluated for their antifungal activity. All the target compounds were determined by 1H-NMR, 13C-NMR, FTIR and HR-MS spectra. The single-crystal structures of compounds 4e, 4h, 5h and 6c were further confirmed using X-ray diffraction. The antifungal activities against Botrytis cinerea (B. cinerea), Alternariasolani (A. solani), Gibberella zeae (G. zeae), Rhizoctorzia solani (R. solani), Colletotrichum orbiculare (C. orbiculare) and Alternaria alternata (A. alternata) were evaluated in vitro. The preliminary bioassays showed that some of the designed compounds displayed the promising antifungal activities against the above tested fungi. Strikingly, the target compounds 5f and 6h exhibited outstanding antifungal activity against B. cinerea at 100 µg/mL, with the corresponding inhibition rates reached 90.1 and 85.0%, which were better than the positive control Osthole (83.6%) and Azoxystrobin (46.5%). The compound 5f was identified as the promising fungicide candidate against B. cinerea with the EC50 values of 5.75 µg/mL, which was obviously better than Osthole (33.20 µg/mL) and Azoxystrobin (64.95 µg/mL). Meanwhile, the compound 5f showed remarkable antifungal activities against R. solani with the EC50 values of 28.96 µg/mL, which was better than Osthole (67.18 µg/mL) and equivalent to Azoxystrobin (21.34 µg/mL). The results provide a significant foundation for the search of novel fluorinated 7-hydroxycoumarin derivatives with good antifungal activity.

High expression of CIN85 promotes proliferation and invasion of human esophageal squamous cell carcinoma.

SH3 domain­containing kinase­binding protein 1 (CIN85), an 85 kDa protein known to be a member of the signal adaptor family, is abnormally expressed in several human malignancies and has been found to be involved in the growth, migration and invasion of these tumors. The objective of the present study was to clarify the clinical significance of CIN85 in human esophageal squamous cell carcinoma (ESCC), as well as its in vitro functions. CIN85 expression was evaluated in 129 cases of ESCC and its adjacent normal tissues using immunohistochemistry to explore its clinical relevance and prognostic value. The functions of CIN85 in the ESCC TE1 cell line were analyzed in vitro using the interfering short hairpin RNA silencing technique. MTS, wound healing, clone formation and Transwell assays were used to detect the proliferation, migration and invasion of ESCC cells. CIN85 expression was identified mainly in ESCCs and their adjacent normal tissues, and the high expression of CIN85 was significantly associated with advanced Tumor Node Metastasis stage and lymph node metastasis. CIN85 gene silencing significantly inhibited TE1 cell proliferation, migration and invasion. These results demonstrated that CIN85 was highly expressed in advanced stage ESCC and lymph node metastasis, and played a critical role in tumor proliferation and progression. Therefore, CIN85 may be a promising therapeutic target for human ESCC.

Modeling the joint distribution of firm size and firm age based on grouped data.

The firm size distribution is highly skewed to the right and often follows a power law. In practice, it is common that firm size and firm age data are aggregated and released as grouped data to avoid disclosure of confidential information. We investigate multiple parametric methods for firm size and firm age modeling based on grouped data, and propose to estimate the joint distribution of firm size and firm age using the Plackett copula. The goodness-of-fit of the estimated marginal distributions are benchmarked with respect to the fit to the whole data and to the upper tails, respectively. The utilization of the proposed methods are demonstrated via an application to the 1977-2014 US firm data. Results show that the generalized lambda distribution has overall better performance in modeling both firm size and firm age data. The exponentiated Weibull distribution also works well in modeling the firm size data. As a by-product, the estimated parameter of the Plackett copula provides a measure of the association between firm size and firm age.

The landscape of gene mutations and clinical significance of tumor mutation burden in patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy.

BACKGROUND: The aim of this study was to evaluate the landscape of gene mutations and the clinical significance of tumor mutation burden (TMB) in patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy. METHODS: A total of 68 patients with soft tissue sarcoma were included. Postoperative tumor tissue specimens from the patients were collected for DNA extraction. Targeted next-generation sequencing of cancer-relevant genes was performed for the detection of gene mutations and the analysis of TMB. Univariate analysis between TMB status and prognosis was carried out using the Kaplan-Meier survival analysis, and multivariate analysis was adjusted by the Cox regression model. RESULTS: No specific genetic mutations associated with soft tissue sarcoma were found. The mutation frequency of TP53, PIK3C2G, NCOR1, and KRAS of the 68 patients with soft tissue sarcoma were observed in 19 cases (27.94%), 15 cases (22.06%), 14 cases (20.59%), and 14 cases (20.59%), respectively. With regard to the analysis of TMB, the overall TMB of the 68 patients with soft tissue sarcoma was relatively low (median: 2.05 per Mb (range: 0∼15.5 per Mb)). Subsequently, TMB status was divided into TMB-Low and TMB-Middle according to the median TMB. Patients with TMB-Low and TMB-Middle were 37 cases (54.41%) and 31 cases (45.59%), respectively. Overall survival analysis indicated that the median overall survival of patients with TMB-Low and TMB-Middle was not reached, and 4.5 years, respectively (P=0.015). CONCLUSION: This study characterizes the genetic background of patients with STS soft tissue sarcoma. The TMB was of clinical significance for patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy.

Meta-Analysis of Two Different Methods for Cervical Esophagogastric Anastomosis: Triangulating Versus Circular Stapling.

Background: The standard treatment for esophageal carcinoma is extensive resection of the tumor and esophagogastric anastomosis despite the high incidence of related anastomotic complications, such as stricture and leakage. Thus, the choice of the cervical esophagogastric anastomotic method-triangulating stapling (TS) versus circular stapling (CS)-is a critical decision for the surgeon. Aim: To compare the incidence of major adverse outcomes between TS and CS in patients with resectable thoracic esophageal cancer. Methods: For this meta-analysis, PubMed, Embase, Wiley Online Library, Google Scholar, Wanfang, and China National Knowledge Infrastructure databases were searched for subject-relevant studies by using a rigorous study protocol established according to the recommendations of the Cochrane Handbook. Anastomotic leakage, anastomotic stricture, and postoperative pulmonary complications were the primary endpoints used for comparison. Relative risk (RR) with 95% confidence intervals (CI) were calculated to assess the strength of association. Results: Six studies were selected by our inclusion/exclusion criteria and represented a total of 739 patients in our meta-analysis of TS (n = 376) versus CS (n = 363). The TS group showed a lower incidence of anastomotic stricture (RR: 0.23 [95% CI: 0.08-0.63]; P = .004) and pulmonary complications (RR: 0.57 [95% CI: 0.37-0.87]; P = .01). However, the incidence of anastomotic leakage was similar for the two groups (RR: 0.66 [95% CI: 0.41-1.09]; P = .1). Subgroup analysis of four studies in which the surgical methods were minimally invasive demonstrated the TS group to have a lower incidence of lung complications (RR: 0.55 [95% CI: 0.35-0.87]; P = .01), anastomotic leakage (RR: 0.36 [95% CI: 0.18-0.74]; P = .005), and anastomotic stricture (RR: 0.23 [95% CI: 0.05-0.98]; P = .05). Conclusion: The TS method for cervical esophagogastric anastomosis after esophagectomy had a lower incidence of anastomotic stricture and postoperative lung complications.

Design, synthesis and antifungal activities of novel pyrrole- and pyrazole-substituted coumarin derivatives.

We synthesized a series of novel pyrrole- and pyrazole-substituted coumarin derivatives and evaluated their antifungal activity against six phytopathogenic fungi in vitro. The primary assay results demonstrated that some designed compounds displayed potent activities. Among them, compounds 5g, 6a, 6b, 6c, 6d and 6h exhibited more effective control than Osthole against Cucumber anthrax and Alternaria leaf spot. Furthermore, compound 5g displayed stronger antifungal activity against Rhizoctorzia solani (EC50 = 15.4 µg/mL) than positive control Osthole (EC50 = 67.2 µg/mL).

Recent Advances in Indazole-Containing Derivatives: Synthesis and Biological Perspectives.

Indazole-containing derivatives represent one of the most important heterocycles in drug molecules. Diversely substituted indazole derivatives bear a variety of functional groups and display versatile biological activities; hence, they have gained considerable attention in the field of medicinal chemistry. This review aims to summarize the recent advances in various methods for the synthesis of indazole derivatives. The current developments in the biological activities of indazole-based compounds are also presented.

The Effects of Intra-Aortic Balloon Pumps on Mortality in Patients Undergoing High-Risk Coronary Revascularization: A Meta-Analysis of Randomized Controlled Trials of Coronary Artery Bypass Grafting and Stenting Era.

BACKGROUND: Intra-aortic balloon pumps (IABP) have generally been used for patients undergoing high-risk mechanical coronary revascularization. However, there is still insufficient evidence to determine whether they can improve outcomes in reperfusion therapy patients, mainly by percutaneous coronary intervention (PCI) with stenting or coronary artery bypass graft (CABG). This study was designed to determine the difference between high-risk mechanical coronary revascularization with and without IABPs on mortality, by performing a meta-analysis on randomized controlled trials of the current era. METHODS: Pubmed and Embase databases were searched from inception to May 2015. Unpublished data were obtained from the investigators. Randomized clinical trials of IABP and non-IABP in high-risk coronary revascularization procedures (PCI or CABG) were included. In the case of PCI procedures, stents should be used in more than 80% of patients. Numbers of events at the short-term and long-term follow-up were extracted. RESULTS: A total of 12 randomized trials enrolling 2155 patients were included. IABPs did not significantly decrease short-term mortality (relative risk (RR) 0.66; 95% CI, 0.42-1.01), or long-term mortality (RR 0.79; 95% CI, 0.47-1.35), with low heterogeneity across the studies. The findings remained stable in patients with acute myocardial infarction with or without cardiogenic shock. But in high-risk CABG patients, IABP was associated with reduced mortality (71 events in 846 patients; RR 0.40; 95%CI 0.25-0.67). CONCLUSION: In patients undergoing high-risk coronary revascularization, IABP did not significantly decrease mortality. But high-risk CABG patients may be benefit from IABP. Rigorous criteria should be applied to the use of IABPs.

Efficacy and Safety of Corticosteroids for Community-Acquired Pneumonia: A Systematic Review and Meta-Analysis.

BACKGROUND: Corticosteroids are an option in the treatment of community-acquired pneumonia (CAP). However, the benefits and adverse effects of corticosteroids, especially in severe CAP, have not been well assessed. METHODS: PubMed, Embase, and Cochrane library databases from inception to May 2015 were searched. Randomized controlled trials (RCTs) and cohort studies that evaluated use of corticosteroids in adult patients with CAP were included. The quality of outcomes was evaluated using Grading of Recommendations Assessment, Development and Evaluation methodology. The Mantel-Haenszel method with random-effects modeling was used to calculate pooled relative risks (RRs) and 95% CIs. RESULTS: Nine eligible RCTs (1,667 patients) and six cohort studies (4,095 patients) were identified. The mean corticosteroid dose and treatment duration were 30 mg/day methylprednisolone for 7 days. Corticosteroids did not have a statistically significant effect on mortality (RR, 0.72; 95% CI, 0.43-1.21; evidence rank, low) in patients with CAP and patients with severe CAP (RCTs: RR, 0.72; 95% CI, 0.43-1.21; evidence rank, low; cohort studies: RR, 1.00; 95% CI, 0.86-1.17 ). Corticosteroids treatment was associated with a decreased risk of ARDS (RR, 0.21; 95% CI, 0.08-0.59) and may reduce lengths of hospital and ICU stay, duration of IV antibiotic treatment, and time to clinical stability. Corticosteroids were not associated with increased rates of adverse events. CONCLUSIONS: Short-term treatment with corticosteroids is safe and may reduce the risk of ARDS, shortening the length of the disease in patients with CAP.

Musashi-2 promotes hepatitis Bvirus related hepatocellular carcinoma progression via the Wnt/ß-catenin pathway.

Our recent study observed that the expression of Musashi-2 (MSI2), a member of the Musashi family, was up-regulated in hepatitis B virus (HBV) related hepatocellular carcinoma parenchymal cells. Using quantitative PCR, tissue microarray (TMA) and immunohistochemical staining, we evaluated MSI2 mRNA and protein levels in tumor tissues from patients with different stages of hepatocellular carcinoma with paired adjacent noncancerous sample sets. The following techniques were used to further investigate MSI2 function and its potential molecular mechanism: RNAi, wound healing assay, Transwell assay, quantitative PCR and western blot analysis. Immunohistochemical detection of MSI2 on a TMA containing 106 paired specimens showed that increased cytoplasmic and nuclear MSI2 staining was significantly associated with tumor size, tumor differentiation, recurrence, TNM stage, vessel invasion and Ki-67 proliferative index. Patients with MSI2-positive tumors had a significantly higher disease recurrence rate and poorer survival than patients with MSI2-negative tumors after radical surgery. Based on univariate analysis, MSI2 expression showed an unfavorable influence on both disease-free survival and overall survival. Multivariate analysis revealed that higher MSI2 expression, together with tumor size, tumor differentiation, tumor thrombus, and Ki-67 expression were independent predictors of overall survival. With MSI2 knockdown, hepatoma cell migration and invasion were inhibited and the expression of ß-catenin, T cell factor (TCF) and lymphoid enhancer factor (LEF) were dysregulated. Thus, we propose that MSI2 may predict unfavorable outcomes in hepatitis B virus related hepatocellular carcinoma and promote cancer progression via the Wnt/ß-catenin signaling pathway.

c-Jun N-terminal kinase 3 expression in the retina of ocular hypertension mice: a possible target to reduce ganglion cell apoptosis.

Glaucoma, a type of optic neuropathy, is characterized by the loss of retinal ganglion cells. It remains controversial whether c-Jun N-terminal kinase (JNK) participates in the apoptosis of retinal ganglion cells in glaucoma. This study sought to explore a possible mechanism of action of JNK signaling pathway in glaucoma-induced retinal optic nerve damage. We established a mouse model of chronic ocular hypertension by reducing the aqueous humor followed by photocoagulation using the laser ignition method. Results showed significant pathological changes in the ocular tissues after the injury. Apoptosis of retinal ganglion cells increased with increased intraocular pressure, as did JNK3 mRNA expression in the retina. These data indicated that the increased expression of JNK3 mRNA was strongly associated with the increase in intraocular pressure in the retina, and correlated positively with the apoptosis of retinal ganglion cells.

Serum total bilirubin and long-term outcome in patients undergoing percutaneous coronary intervention.

PURPOSE: The purpose of this study was to investigate the associated between serum total bilirubin (STB) levels and long-term outcomes in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). METHODS: A total of 1,273 consecutive patients were enrolled. Patients were grouped according to their baseline STB levels: Group 1 (STB < 3.4 µmol/L), Group 2 (3.4 µmol/L ≤ STB ≤ 10.3 µmol/L), Group 3 (10.3 µmol/L < STB ≤ 17.1 µmol/L), and Group 4 (STB < 17.1 µmol/L) and the rate of major adverse cardiovascular events (MACE) was determined RESULTS: A total of 1,152 patients were successfully followed up (90.5%) for a mean period of 30 ± 5 months, including 187 patients experiencing a major adverse cardiovascular event (MACE: death from any cause, myocardial infarction, repeat revascularization or readmission). The MACE rate in Groups 3 and 4 was lower than in Groups 1 and 2 (P < 0.01). After adjusted the confounding factors with Cox regression analysis, the MACE rates in Groups 2-4 were still lower than in Group 1 (Group 2, RR=0.293, 95% CI 0.167-0.517, P < 0.01; Group 3, RR=0.142, 95% CI 0.065-0.312, P < 0.01; Group 4, RR=0.134, 95% CI 0.071-0.252, P < 0.01). The cumulative survival rates of Groups 3 and 4 were higher than that of Groups 1and 2 (P < 0.01). CONCLUSIONS: High STB concentration is associated with lower MACE in patients with ACS after PCI.

The effects of perioperative ß-blockers on mortality in patients undergoing non-cardiac surgery in real world: a meta-analysis of cohort studies.

BACKGROUND: Despite the fact that recent evidence from meta-analysis of randomized trials indicates an increase in mortality, perioperative treatment with ß-blockers is still widely advocated. We therefore performed a meta-analysis of cohort studies to evaluate the effects of perioperative ß-blockers on mortality in patients undergoing non-cardiac surgery in the real world scenarios. METHODS: We searched PubMed and Embase from the inception to April 2014 for cohort studies, assessing the effect of perioperative ß-blockers on mortality in patients undergoing non-cardiac surgery. Adjusted relative risk (RR) with 95% confidence interval (CI) was pooled using random effect models. RESULTS: Eight cohort studies with a total of 470,059 participants (180,441 patients in the ß-blocker group and 289,618 patients in the control group) were included in this meta-analysis. Perioperative ß-blockers were not associated with a reduced risk of mortality (RR=0.88, 95% CI, 0.75 to 1.04), postoperation myocardial infarction (RR=1.30, 95% CI, 0.76 to 2.23), and postoperation stroke (RR=1.17, 95% CI, 0.53 to 2.57). However, in subgroup analysis of mortality, taking ß-blockers on the day of surgery caused statistically significant increase in mortality of 91% (RR=1.91, 95% CI, 1.01 to 3.62). CONCLUSIONS: In the real world scenarios, for patients undergoing non-cardiac surgery, the routine use of ß-blockers does not seem to reduce the risk of death. Moreover, those who are taking ß-blockers on the day of surgery may have an increased risk of postoperative mortality. However, these results should be interpreted with caution because of the significant heterogeneity across the studies.

Effect of statin therapy on mortality from infection and sepsis: a meta-analysis of randomized and observational studies.

INTRODUCTION: Observational data have suggested that statin therapy may reduce mortality in patients with infection and sepsis; however, results from randomized studies are contradictory and do not support the use of statins in this context. Here, we performed a meta-analysis to investigate the effects of statin therapy on mortality from infection and sepsis. METHODS: We searched electronic databases (PubMed and Embase) for articles published before November 2013. Randomized or observational studies reporting the effects of statin therapy on mortality in patients with infection or sepsis were eligible. Randomized and observational studies were separately pooled with relative risks (RRs) and random-effects models. RESULTS: We examined 5 randomized controlled trials with 867 patients and 27 observational studies with 337,648 patients. Among the randomized controlled trials, statins did not significantly decrease in-hospital mortality (RR, 0.98; 95% confidence interval (CI), 0.73 to 1.33) or 28-day mortality (RR, 0.93; 95% CI, 0.46 to 1.89). However, observational studies indicated that statins were associated with a significant decrease in mortality with adjusted data (RR, 0.65; 95% CI, 0.57 to 0.75) or unadjusted data (RR, 0.74; 95% CI, 0.59 to 0.94). CONCLUSIONS: Limited evidence suggests that statins may not be associated with a significant reduction in mortality from infection and sepsis. Although meta-analysis from observational studies showed that the use of statins was associated with a survival advantage, these outcomes were limited by high heterogeneity and possible bias in the data. Therefore, we should be cautious about the use of statins in infection and sepsis.

Examination of artificial MiRNA mimics with centered-site complementarity for gene targeting.

BACKGROUND: MiRNA primarily acts to repress gene expression at the post-transcriptional level through imperfect complementarity of its 5' region to the "seed site" in the 3' untranslated region of target mRNAs, with its "3'-supplementary site" and "center site" also playing important roles under certain circumstances. The aim of this study was to test if artificial miRNA mimics (miR-Mimics) that are designed to target the "centered sites" without "seed sites" complementarity are able to repress gene expression as natural miRNAs. METHODS: We designed miR-Mimics carrying centered-site matches (CS-miR-Mimics) or seed-site matches (SS-miR-Mimics) and siRNA to two antiapoptotic genes BCL2 and AKT1. We tested the gene targeting of these constructs using real-time RT-PCR and Western blot to quantify mRNA and protein levels of BCL2 and AKT1, respectively, luciferase reporter gene assay to investigate the interaction between miR-Mimics and their target sites, and cell survival assay to study the functional outcomes of the miR-Mimics. RESULTS: We found that CS-miR-Mimic, SS-miR-Mimic and siRNA, all down regulated the mRNA and protein levels of their cognate target BCL2 or AKT1 in a concentration-dependent manner. Luciferase reporter gene assay further confirmed the functional interactions of CS-miR-Mimic, SS-miR-Mimic and siRNA with their target sites. We then observed that the miR-Mimics and siRNAs were all able to induce cell death, as indicated by the reduced survival rate of cells. CONCLUSIONS: We have provided evidence for the feasibility of CS-miR-Mimics for post-transcriptional repression of genes, which can be designed to have reduced numbers of seed type off-target sites compared to the number of target sites from an average endogenous seed-site miRNA. CS-miR-Mimics may be a novel approach for miRNA research requiring miRNA gain-of-function.