High-throughput screening identifies established drugs as SARS-CoV-2 PLpro inhibitors

A new coronavirus (SARS-CoV-2) has been identified as the etiologic agent for the COVID-19 outbreak. Currently, effective treatment options remain very limited for this disease; therefore, there is an urgent need to identify new anti-COVID-19 agents. In this study, we screened over 6,000 compounds that included approved drugs, drug candidates in clinical trials, and pharmacologically active compounds to identify leads that target the SARS-CoV-2 papain-like protease (PLpro). Together with main protease (M

Survivin inhibitor YM155 induces apoptosis of thyroid carcinoma cell line B-CPAP and potential mechanisms / 中国免疫学杂志

Objective:To investigate the effects of survivin inhibitor YM155{1-(2-methoxyethyl)-2-methyl-4,9-dioxo-3-(pyrazin-2-ylmethyl)-4,9-dihydro-1H-naphtho[2,3-d] imidazolium bromide} on cell viability,apoptosis and Cysteinyl aspartate specific proteinase-3,Cysteinyl aspartate specific proteinase-8,Cysteinyl aspartate specific proteinase-9 of the thyroid carcinoma cell line B-CPAP in order to discuss mitochondrial mechanisms of apoptosis.Methods: B-CPAP cells were cultured in vitro and treated with YM155 at various concentrations(0,0.5,1,2,4,8 nmol/L)for 24,48 and 72h.The cell viability of B-CPAP cells were measured by CCK-8 assay.B-CPAP cells were randomly divided into 4 groups:B-CPAP cells were treated with YM155 at various concentrations(0,1,2 nmol/L)and 5 μmol/L Cisplatin(the positive control group)for 24 h.The effects of YM155 on B-CPAP cells apoptosis were evaluated by TUNEL and flow cytometry Annexin V-FITC/PI method.The expression level of Survivin and Caspase-3,Caspase-8 ,Caspase-9 were detected by Western blot analysis.Results: Compared with the 0 nmol/L group,YM155 significantly inhibited the cell viability of B-CPAP cells and induced their apoptosis (P<0.05 or P<0.01).Compared with the 0 nmol/L group,YM155 significantly reduced the expression level of Survivin and upregulated Caspase-3,Caspase-8 ,Caspase-9(P<0.05 or P<0.01).Conclusion: YM155 can inhibit the cell viability of B-CPAP cells and induce apoptosis,its possible mechanisms maybe related to upregulated expression level of Caspase-3,Caspase-8 and Caspase-9.

Effects of survivin inhibitor YM155 on mitochondrial apoptotic pathway of retinoblastoma Y79 cells / 中国病理生理杂志

AIM:To investigate the effects of survivin inhibitor YM155 {4,9-dihydro-1-(2-methoxyethyl)-2-methyl-4,9-dioxo-3-(2-pyrazinylmethyl)-4,9-dihydro-1H-naphtho[2,3-d]imidazolium bromide} on the apoptosis, mito-chondrial membrane potential (Δψm) and cytochrome C (Cyt C) of retinoblastoma Y79 cells, and to analyze the mitochon-drial mechanisms of apoptosis .METHODS:Y79 cells were cultured in vitro and treated with YM155 at concentrations of 0, 0.5, 1, 2, 4 and 8 nmol/L.The cells in control group were treated without YM 155.The proliferation of Y79 cells were measured by CCK-8 assay and bromodeoxyuridine ( BrdU) labeling assay .Y79 cells were randomly divided into 4 groups:control group ( with equal volume of RPMI-1640 nutrient medium ) , positive control group ( 10 nmol/L topotecan ) , low-dose (1 nmol/L) YM155 group and high-dose (2 nmol/L) YM155 group.The effects of YM155 on the apoptosis, the changes of Δψm , the mitochondrial distribution and the protein level of Cyt C in the Y 79 cells were evaluated by flow cytom-etry with Annexin V-FITC/PI staining, JC-1 staining, immunofluorescence analysis and Western blot , respectively.RE-SULTS:Compared with control group , YM155 significantly inhibited the proliferation of Y 79 cells and induced apoptosis (P<0.05).YM155 significantly reduced Δψm of the Y79 cells, promoted Cyt C which released from mitochondria to the cytosol and reduced the protein level of Cyt C in the mitochondria (P<0.05).CONCLUSION:YM155 inhibits Y79 cell proliferation and induces apoptosis , and the possible mechanisms may be involved in the mitochondrium-mediated apoptotic pathway .

Effects of YM155 on proliferation and apoptosis of triple negative breast cancer MDA-MB-231 cells / 中华内分泌外科杂志

Objective To investigate the apoptosis induction effects and the possible mechanism of YM155 on triple negative breast cancer MDA-MB-231cells.Methods MDA-MB-231 cells were treated with dif-ferent concentrations of YM 155, and the survival rate of the cells was determined by CCK-8 assay and the half maximal inhibitory concentration ( IC50 ) value of YM155 was calculated .The apoptosis rate was examined by An-nexin V-FITC/PI double staining.mRNA expression of survivin and bcl-2 in MDA-MB-231cells was detected by RT-PCR.The protein expression of survivin , bcl-2, caspase-3, and PARP were detected by Western blot .Re-sults YM155 significantly inhibited the growth of MDA-MB-231 cells in a dose-and-time-dependenct way .IC50 was(1.749 ±0.265) ng/ml and(0.823 ±0.125) ng/ml respectively at 24 and 48 hours.The apoptosis rate of cells treated with 0.5 ng/ml, 1.0 ng/ml, and 1.5 ng/ml YM155 was (10.93 ±0.94)%,(31.10 ±1.51)%, and(46.83 ±2.92)%respectively, which had significant difference compared to that of the control group (6.4 ± 1.2)%(P<0.01).YM155 could significantly decrease mRNA and protein expression of surviving , besides, it reduced bcl-2 expression and increased caspase-3 and PARP protein expression .Conclusions YM155 can ef-fectively induce the apoptosis of MDA-MB-231 cells by downregulating survivin and activating caspase pathway . Bcl-2 might play a role in the apoptosis .