Chemically Cross-Linked Hammerhead Ribozyme as an Efficient RNA Interference Tool.

RNA-cleaving ribozymes are promising candidates as general tools of RNA interference (RNAi) in gene manipulation. However, compared with other RNA systems, such as siRNA and CRISPR technologies, the ribozyme tools are still far from broad applications on RNAi due to their poor performance in the cellular context. In this work, we report an efficient RNAi tool based on chemically modified hammerhead ribozyme (HHR). By the introduction of an intramolecular linkage into the minimal HHR to reconstruct the distal interaction within the tertiary ribozyme structure, this cross-linked HHR exhibits efficient RNA substrate cleavage activities with almost no sequence constraint. Cellular experiments suggest that both exogenous and endogenous RNA expression can be dramatically knocked down by this HHR tool with levels comparable to those of siRNA. Unlike the widely applied protein-recruiting RNA systems (siRNA and CRISPR), this ribozyme tool functions solely on RNA itself with great simplicity, which may provide a new approach for gene manipulation in both fundamental and translational studies.

Rheumatoid arthritis and hypothyroidism: a bidirectional Mendelian randomization study.

Object: Though significant correlations between rheumatoid arthritis (RA) and hypothyroidism have been found in earlier observational studies, their underlying causal relationship is still unknown. Mendelian randomization (MR) was used in the current study to assess the bidirectional causation between RA and hypothyroidism. Method: We gathered summary data from genome-wide association studies (GWASs) of RA and hypothyroidism in people of European descent. Then, using data from the FinnGen consortium, we replicated our findings. Three approaches were employed to assess the causal link between RA and hypothyroidism: MR-Egger, weighted median (WM), and inverse variance weighted (IVW). The pleiotropy and heterogeneity were examined using a variety of techniques, including the MR-Egger intercept, the MR-PRESSO approach, the leave-one-out method, and the Cochran's Q test. Results: The study looked at a bidirectional incidental relationship between RA and hypothyroidism. The risk of hypothyroidism increased with RA (IVW odds ratio (OR) = 1.28, 95% confidence interval (CI) = 1.18-1.39, P = 8.30E-10), as did the risk of secondary hypothyroidism (IVW OR = 1.12, 95% CI = 1.05-1.21, P = 9.64E-4). The results of reverse MR analysis revealed that hypothyroidism (IVW OR = 1.68, 95% CI = 1.51-1.88, P = 4.87E-21) and secondary hypothyroidism (IVW OR = 1.74, 95% CI = 1.50-2.01, P = 1.91E-13) were linked to an increased risk of RA. Additionally, we obtain the same results in the duplicated datasets as well, which makes our results even more reliable. This study revealed no evidence of horizontal pleiotropy. Conclusion: The present study established a bidirectional causal link between RA and hypothyroidism. However, it differs slightly from the findings of prior observational studies, suggesting that future research should concentrate on the interaction mechanisms between RA and hypothyroidism.

Clinical Characterization of Mismatch Repair Gene-Deficient Metastatic Castration-Resistant Prostate Cancer.

Mismatch repair-deficient (dMMR) prostate cancer is rare and has not been well studied. We aimed to evaluate the clinical characterization of dMMR metastatic castration-resistant prostate cancer (mCRPC) patients. The MMR genes include MLH1, MLH3, MSH2, MSH6, PMS1, PMS2, and EPCAM, and were analyzed by targeted sequencing of plasma cell-free DNA samples. A total of 109 mCRPC patients were identified, including 50 patients with MMR alterations (pathogenic alterations, n = 7; alterations of unknown significance, n = 43) and 59 patients with wild-type MMR. For the seven patients with pathogenic MMR alterations, the median age at diagnosis was 63.5 years, and 42.9% had a Gleason score ≥8. The median time from androgen deprivation therapy (ADT) initiation to CRPC was 24 months. Compared with the wild-type MMR subgroup, patients with MMR alterations, pathogenic MMR alterations, or MMR alterations of unknown significance showed higher rates of hotspot missense mutations or copy number amplifications in the AR gene (24/50 vs. 10/59, P = 7.8 × 10-4; 7/7 vs. 10/59, P = 2.5 × 10-5; 17/43 vs. 10/59, P = 0.013). The presence of any MMR alterations was associated with an inferior response to abiraterone [median progression-free survival (PFS): 5.0 vs. 10.9 months, P = 0.022]. Shorter PFS times were observed in both the pathogenic MMR alteration subgroup (median PFS: 5 months) and the MMR alterations of unknown significance subgroup (median PFS: 5.3 months), compared with the PFS of those with wild-type MMR genes (median PFS: 10.9 months, P = 0.052). There was no statistically significant difference in response to docetaxel chemotherapy between the MMR alterations of unknown significance and the wild-type MMR subgroups (median PFS: 8.2 vs. 8.1 months, P = 0.23). Our results demonstrate that dMMR mCRPC patients have an equivalent response to standard ADT and taxane-based chemotherapy treatments compared with wild-type MMR patients. Patients with both pathogenic and unknown significance alterations of MMR genes had poorer responses to abiraterone therapy.

Gene set based systematic analysis of prostate cancer and its subtypes.

Aim: A gene set based systematic analysis strategy is used to investigate prostate tumors and its subclusters with focuses on similarities and differences of biological functions. Results: Dysregulation of methylation status, as well as RAS/RAF/ERK and PI3K-ATK signaling pathways, were found to be the most dramatic changes during prostate cancer tumorigenesis. Besides, neural and inflammation microenvironment is also significantly divergent between tumor and adjacent tissues. Insights of subclasses within prostate tumor cohorts revealed four different clusters with distinct gene expression patterns. We found that samples are mainly clustered by immune environments and proliferation traits. Conclusion: The findings of this article may help to advance the progress of identifying better diagnosis biomarkers and therapeutic targets.

MicroRNA­494 inhibits apoptosis of murine vascular smooth muscle cells in vitro.

Apoptosis of vascular smooth muscle cells (VSMCs) is a process that regulates vessel remodeling in various cardiovascular diseases. The specific mechanisms that control VSMC apoptosis remain unclear. The present study aimed to investigate whether microRNA­494 (miR­494) is involved in regulating VSMC apoptosis and its underlying mechanisms. Cell death ELISA and terminal deoxynucleotidyl­transferase­mediated dUTP nick end labeling assays were used to detect apoptosis of murine VSMCs following stimulation with tumor necrosis factor­α (TNF­α). The results indicated that TNF­α upregulated VSMC apoptosis in a dose­dependent manner. Microarray analysis was used to evaluate the expression profile of microRNAs following TNF­α stimulation in murine VSMCs. The expression of miR­494 was downregulated, whereas B­cell lymphoma-2­like 11 (BCL2L11) protein expression levels were upregulated in VSMCs following treatment with TNF­α. Luciferase reporter assays confirmed that BCL2L11 was a direct target of miR­494. Transfection with miR­494 mimics decreased VSMC apoptosis and downregulated BCL2L11 protein levels. Conversely, transfection with miR­494 inhibitors increased cell apoptosis and upregulated BCL2L11 protein levels, suggesting that miR­494 may function as an essential regulator of BCL2L11. The increase in apoptosis caused by miR­494 inhibitors was abolished in cells co­transfected with BCL2L11­targeting small interfering RNA. The findings of the present study revealed that miR­494 inhibited TNF­α­induced VSMC apoptosis by downregulating the expression of BCL2L11.

The effect of metformin therapy on incidence and prognosis in prostate cancer: A systematic review and meta-analysis.

The relationship between metformin and prostate cancer (PCa) remains controversial. To clarify this association, the PubMed, Embase and Cochrane library databases were systematically searched from their inception dates to May 23, 2018, using the keywords "metformin" and "prostate cancer" to identify the related studies. The results included incidence, overall survival (OS), PCa-specific survival (CSS) and recurrence-free survival (RFS), which were measured as hazard ratios (HR) with a 95% confidence interval (95% CI) using Review Manager 5.3 software. A total of 30 cohort studies, including 1,660,795 patients were included in this study. Our study revealed that metformin treatment improves OS, CSS and RFS in PCa (HR = 0.72, 95% CI: 0.59-0.88, P = 0.001; HR = 0.78, 95% CI: 0.64-0.94, P = 0.009; and HR = 0.60, 95% CI: 0.42-0.87 P = 0.006, respectively) compared with non-metformin treatment. However, metformin usage did not reduce the incidence of PCa (HR = 0.86, 95% CI: 0.55-1.34, P = 0.51). In conclusion, compared with non-metformin treatment, metformin therapy can significantly improve OS, CSS and RFS in PCa patients. No association was noted between metformin therapy and PCa incidence. This study indicates a useful direction for the clinical treatment of PCa.

Spider peptide toxin lycosin-I induces apoptosis and inhibits migration of prostate cancer cells.

Spider toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. The aim of the present investigation was to explore different antitumor effects of the spider peptide toxin lycosin-I through different pathways at different concentrations. It was found that by inactivating STAT3 pathway, high concentrations of lycosin-I induce apoptosis in prostate cancer cells and low concentrations of lycosin-I inhibit the migration of prostate cancer cells. This finding provides favorable evidence for further study of the molecular diversity of spider toxins. Impact statement The spider peptide toxin has become an important research topic. These toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. Inspired by previous studies, the present study aims to investigate the effects of different concentrations of lycosin-I on the invasiveness and apoptosis of human prostate cancer cells. The findings provide favorable evidence for further study of the molecular diversity of spider toxins.