Mining and analysis of ADE signals of two camptothecin topoisomerase 1 inhibitors / 中国药房

OBJECTIVE To mine and analyze the adverse drug events （ADE） signals of two camptothecin topoisomerase 1 inhibitors， i.e. irinotecan and topotecan， and to provide reference for clinical medication safety. METHODS Based on the U.S. Food and Drug Administration Adverse Event Reporting System （FAERS） database， ADE report data for the aforementioned two drugs were extracted from January 1， 2004 to March 31， 2023. After processing the data， signal mining was conducted by using the reporting odds ratio in conjunction with the Bayesian confidence propagation neural network， followed by analysis. RESULTS A total of 14 738 relevant ADE reports were screened， among which 11 483 were associated with irinotecan and 3 255 with topotecan. The ADE reports for irinotecan were predominantly male， whereas for topotecan， they were predominantly female； the age of patients using the two drugs mainly concentrated in 45-＜75 years old. A total of 847 signals were detected， involving 24 system organ classes （SOCs）. Among them， 565 signals of irinotecan were detected， involving 24 SOCs， primarily concentrating on gastrointestinal disorders， general disorders and administration site conditions， blood and lymphatic system disorders； the most frequently reported ADE was diarrhea， and the ADE with the strongest signal intensity was cholinergic syndrome. A total of 282 signals of topotecan were detected， involving 22 SOCs， primarily concentrating on general disorders and administration site conditions， investigations， blood and lymphatic system disorders， and gastrointestinal disorders； the most frequently reported ADEs were death and anemia， and the ADE with the strongest signal intensity was febrile bone marrow aplasia. ADE signals for irinotecan such as metastatic colorectal cancer， peripheral sensory neuropathy， steatohepatitis， and those for topotecan such as iris atrophy， retinal degeneration， vitreous hemorrhage， were not documented in their respective drug instruction. CONCLUSIONS ADEs of irinotecan and topotecan primarily involve the digestive and hematologic systems， warranting close clinical monitoring. Cholinergic syndrome caused by irinotecan should be concerned. In addition， patients receiving irinotecan should also be monitored for ADE such as metastatic colorectal cancer， peripheral sensory neuropathy， steatohepatitis， and proteinuria； for patients using topotecan， enhanced surveillance of ocular diseases is recommended to ensure medication safety.

Molecular mechanism of topoisomerase I inhibitor in protecting against experimental acute pancreatitis in mice / 中华胰腺病杂志

Objective:To investigate the protective mechanism of topoisomerase I inhibitor on pancreatic acinar cells and lung during acute pancreatitis (AP) in mice.Methods:Eighteen Balb/C male mice were randomly divided into three groups using random number method: control group, AP group and CPT+ AP group. AP model was established by intraperitoneal injection of caerulein and lipopolysaccharide. CPT+ AP group received intraperitoneal injection of camptothecin (CPT, 50 mg/kg) before AP induction. Mice in control group were intraperitoneal injected with an equal volume of normal saline. The pathological examinations of pancreas and lung tissue were analyzed. The serum levels of amylase and lipase were detected by enzyme linked immunosorbent assay (ELISA) and the mRNA expression of IL-1 and IL-6 were analyzed by reverse transcription-polymerase chain reaction (RT-PCR); the infiltration of CD 45+ cells in pancreas and lung tissue as well as the expression of phosphorylated mixed lineage kinase domain-like protein(MLKL) in pancreas were detected by immunohistochemistry; the apoptosis index of pancreatic cells was analyzed by TUNEL assay. Results:The pathological scores of pancreas and lung tissue, serum levels of amylase and lipase in CPT+ AP group were [(2.30±0.31), (2.29±0.34), (1742.33±183.51)U/L and (46.90±2.17)U/L], which were significantly lower than those in AP group [(5.06±0.88), (3.40±0.09), (2385.33±383.10)U/L and (69.13±9.76)U/L]; the mRNA expression of IL-1 and IL-6 in pancreatic tissue were 95.79±48.11, 255.50±213.32, which were also remarkably lower than those in AP group (212.35±80.61, 1006.80±509.06); the infiltration of CD 45+ inflammatory cells in pancreas and lung were (14.25±5.32, 29.20±4.44)/high power field, which were notably lower than those in AP group (59.83±13.67, 58.25±5.91)/high power field; the apoptosis index of pancreatic cells was significantly higher than that in AP group [(3.64±1.16)% vs (1.92±0.29)%]; the histochemistry score of phosphorylated MLKL protein in pancreatic tissue was significantly lower than that in AP group (1.75±0.20 vs 4.53±1.28), and the differences were statistically significant (all P value <0.05). Conclusions:Topoisomerase I inhibitor could induce the apoptosis of pancreatic acinar cells and inhibit the death mode of necrotic pancreatic acinar cells during AP remodeling, thus reducing pancreatic local injury and AP-associated lung injury.

Topoisomerase Ⅱα Gene as a Marker for Prognostic Prediction of Hepatocellular Carcinoma: A Bioinformatics Analysis / 中国医学科学杂志(英文版)

Objective To investigate the expression of topoisomeraseⅡα (TOP2α) in hepatocellular carcinoma (HCC) and its role in predicting prognosis of HCC patients. Methods We used HCC-related datasets in UALCAN, HCCDB, and cBioPortal databases to analyze the expression and mutation of TOP2α and its co-expressed genes in HCC tissues. GO function and KEGG pathway enrichment of TOP2α and its co-expressed genes were identified. The TIMER database was used to analyze infiltration levels of immune cells in HCC. The impacts of TOP2α and its co-expression genes and the infiltrated immune cells on the survival of HCC patients were assayed by Kaplan-Meier plotter analysis. Results TOP2α and its co-expression genes were highly expressed in HCC (P< 0.001) and detrimental to overall survival of HCC patients (P< 0.001). TOP2α and its co-expression genes were mainly involved in cell mitosis and proliferation, and cell cycle pathway (ID: hsa04110, P = 0.001945). TOP2α and its co-expression genes were mutated in HCC and the mutations were significantly detrimental to overall survival (P = 0.0247) and disease-free survival (P = 0.0265) of HCC patients. High TOP2α expression was positively correlated with the infiltration of B cell (r = 0.459, P< 0.01), CD8+ T cell (r = 0.312, P< 0.01), CD4+ T cell (r = 0.370, P< 0.01), macrophage (r = 0.459, P< 0.01), neutrophil (r = 0.405, P< 0.01), and dendritic cell (r = 0.473, P< 0.01) in HCC. The CD8+ T cell infiltration significantly prolonged the 3- and 5-year survival of HCC patients (all P< 0.05), and CD4+ T cell infiltration significantly shortened the 3-, 5-, and 10-year survival of HCC patients (all P< 0.05). ConclusionTOP2α may be an oncogene, which was associated with poor prognosis of HCC patients and could be used as a biomarker for the prognostic prediction of HCC.

Target-based anticancer indole derivatives and insight into structure‒activity relationship: A mechanistic review update (2018-2021)

Cancer, which is the uncontrolled growth of cells, is the second leading cause of death after heart disease. Targeting drugs, especially to specific genes and proteins involved in growth and survival of cancer cells, is the prime need of research world-wide. Indole moiety, which is a combination of aromatic-heterocyclic compounds, is a constructive scaffold for the development of novel leads. Owing to its bioavailability, high unique chemical properties and significant pharmacological behaviours, indole is considered as the most inquisitive scaffold for anticancer drug research. This is illustrated by the fact that the U.S. Food and Drug Administration (FDA) has recently approved several indole-based anticancer agents such as panobinostat, alectinib, sunitinib, osimertinib, anlotinib and nintedanib for clinical use. Furthermore, hundreds of studies on the synthesis and activity of the indole ring have been published in the last three years. Taking into account the facts stated above, we have presented the most recent advances in medicinal chemistry of indole derivatives, encompassing hot articles published between 2018 and 2021 in anticancer drug research. The recent advances made towards the synthesis of promising indole-based anticancer compounds that may act via various targets such as topoisomerase, tubulin, apoptosis, aromatase, kinases, etc., have been discussed. This review also summarizes some of the recent efficient green chemical synthesis for indole rings using various catalysts for the period during 2018-2021. The review also covers the synthesis, structure‒activity relationship, and mechanism by which these leads have demonstrated improved and promising anticancer activity. Indole molecules under clinical and preclinical stages are classified into groups based on their cancer targets and presented in tabular form, along with their mechanism of action. The goal of this review article is to point the way for medicinal chemists to design and develop effective indole-based anticancer agents.

Anticorpos anti topoisomerase 1 no lúpus eritematoso sistêmico / Anti-topoisomerase 1 antibodies in systemic lupus erythematosus

Antitopoisomerase-1 (ou Scl-70) é um autoanticorpo considerado como biomarcador da forma difusa de esclerodermia. Alguns autores o têm encontrado em pacientes com lúpus. O objetivo deste estudo foi estudar a presença do anticorpo Scl-70 em lúpus eritematoso sistêmico (SLE). É pesquisa com 94 pacientes com LES para anticorpo anti Scl-70 usando o kit comercial de ELISA Virgo™, Columbia, USA. Dados clínicos, epidemiológicos e sorológicos foram obtidos dos prontuários. Como resultado, somente 2 pacientes (2.1%) tinham anticorpos anti Scl-70 em baixos títulos. Nenhum deles tinha características de esclerodermia. Em conclusão, não se confirmam achados anteriores acerca da presença de anti Scl-70 em lúpus. Este anticorpo parece ser específico para esclerodermia.

Antitopoisomerase-1 (or Scl-70) is an autoantibody considered as a biomarker of the diffuse form of scleroderma. Some authors have found it in lupus patients. The aim of this study was to study the presence of the Scl-70 antibody in systemic lupus erythematosus (SLE). It is screened with 94 SLE patients for anti Scl-70 antibody using the commercial Virgo™ ELISA kit, Columbia, USA. Clinical, epidemiological and serological data were obtained from medical records. As a result, only 2 patients (2.1%) had anti-Scl-70 antibodies at low titers. None of them had features of scleroderma. In conclusion, previous findings regarding the presence of anti Scl-70 in lupus are not confirmed. This antibody appears to be specific for scleroderma.

In silico and in vitro cytotoxicity profile of hydroalcoholic extract/ fraction(s) of Pachygone ovata

Medicinal plants have been used in the past for the treatment of diseases and continue to be an important reservoirfor the development of new drugs. With the increasing burden of cancer globally, there is a need to find neweranticancer agents. The process of identification and evaluation of cytotoxic molecules from plants can be achievedconveniently by using simple yet reliable screening models and combining with in silico techniques. Pachygone ovata,least explored plant from Menispermaceae family, is known to be rich in alkaloids. This study aimed to identify thecytotoxic constituents from Pachygone ovata through bioactivity-guided fractionation using Brine shrimp lethalitybioassay as a screening model. The active fraction in this assay was evaluated for its in vitro cytotoxic activity onhuman tumor cell lines. Some reported alkaloids were studied for their binding affinities with topoisomerase II bymolecular docking. The study revealed the cytotoxic constituents from P. ovata. The study also revealed alkaloids withhigher binding affinity with topoisomerase II, and the scope for further use leads to the development of new drugs.

Evaluation of topoisomerase II, ki-67, and P53 expression in non-muscle-invasive urothelial carcinoma and their clinical significance

Background: Transurethral resection of tumor is the main treatment of non-muscle-invasive urothelial carcinoma, but it is associated with high rate of recurrence and/or progression and this arouses the need for adjuvant therapy. Topoisomerase II (Top II), KI-67, and P53 are proliferation and cell cycle regulation markers that may predict tumor response to therapy. Aim: This study aimed to assess Top II, KI-67, and P53 expression and their effect on clinical outcome and response to therapy of non-muscle-invasive urothelial carcinoma. Materials and Methods: Fifty cases of non-muscle invasive urothelial carcinoma were collected; Top II, KI-67, and P53 expression was evaluated. Patients received treatment then tumor recurrence was correlated with the expression of previous markers. Results: There was a significant association between high Top II score, P53, and KI-67 and high tumor grade (P = 0.0001, 0.001, and 0.0001), submucosal infiltration (P = 0.0001 and 0.01), and recurrence (P = 0.01, 0.001, and 0.001). Conclusion: Top II, P53, and KI-67 may predict tumor response to therapy and the clinical outcome in non-muscle-invasive urothelial carcinoma.

Novel berberine derivatives: Design, synthesis, antimicrobial effects, and molecular docking studies / 中国天然药物

A series of berberine derivatives were synthesized by introducing substituted benzyl groups at C-9. All these synthesized compounds (4a-4m) were screened for their in vitro antibacterial activity against four Gram-positive bacteria and four Gram-negative bacteria and evaluated for their antifungal activity against three pathogenic fungal strains. All these compounds displayed good antibacterial and antifungal activities, compared to reference drugs including Ciprofloxacin and Fluconazole; Compounds 4f, 4g, and 4l showed the highest antibacterial and antifungal activities. Moreover, all the synthesized compounds were docked into topoisomerase II-DNA complex, which is a crucial drug target for the treatment of microbial infections. Docking results showed that H-bond, π-π stacked, π-cationic, and π-anionic interactions were responsible for the strong binding of the compounds with the target protein-DNA complex.

Novel berberine derivatives: Design, synthesis, antimicrobial effects, and molecular docking studies / 中国天然药物

A series of berberine derivatives were synthesized by introducing substituted benzyl groups at C-9. All these synthesized compounds (4a-4m) were screened for their in vitro antibacterial activity against four Gram-positive bacteria and four Gram-negative bacteria and evaluated for their antifungal activity against three pathogenic fungal strains. All these compounds displayed good antibacterial and antifungal activities, compared to reference drugs including Ciprofloxacin and Fluconazole; Compounds 4f, 4g, and 4l showed the highest antibacterial and antifungal activities. Moreover, all the synthesized compounds were docked into topoisomerase II-DNA complex, which is a crucial drug target for the treatment of microbial infections. Docking results showed that H-bond, π-π stacked, π-cationic, and π-anionic interactions were responsible for the strong binding of the compounds with the target protein-DNA complex.

Expression of SIRT1 protein in gastric cancer and its relationship with P-gp and Top-Ⅱ alpha / 中国现代普通外科进展

Objective:Explore the expression of SIRT1 protein in gastric cancer tissues and cells.Analyze the correlation of SIRT1 protein expression and multidrug resistance protein P-gp and Top-Ⅱ alpha.Methods:Immunohistochemical to detect SIRT1,P-gp and Top-Ⅱ alpha protein in 15 cases of gastric cancer tissue and 15 cases of normal gastric mucosa tissues.Western blot test the expression of SIRT1 protein in normal gastric mucosa epithelial cell line GES-1 and human gastric cancer cell line SGC7901,MKN45,MKN28,HGC27,AGS and MGC803.Western blot test the expression of SIRT1,P-gp and Top-Ⅱ alpha protein in normal gastric mucosa epithelial cell line GES-1 and human gastric cancer cell line SGC7901,MKN45.After siRNA-SIRT1/liposome transfection gastric cancer cells SGC7901,western blot test the changes of expression of SIRT1,P-gp and Top-Ⅱ alpha protein and MTT test the changes of SGC7901 cells proliferation in vitro and the sensitivity of chemotherapy drugs 5-Fu.Results:In 15 cases of gastric cancer tissue have the positive expression of 15 cases of SIRT1 protein,13 cases of P-gp protein and 3 cases of Top-Ⅱ alpha protein.In 15 cases of normal gastric mucosa tissues have the positive expression of 6 cases of SIRT1 protein,5 cases of P-gp protein and 0 cases of Top-Ⅱ alpha protein.The relative quantity of SIRT1 protein expression average were 0.385,0.827,0.009,0.232,0.275,0.159,0.275 in GES-1,SGC7901,MKN45,MKN28,HGC27,AGS and MGC803,respectively.The relative quantity of P-gp protein expression average were 0.339,0.526,1.03 in GES 1,SGC7901 and MKN45 and Top-Ⅱ alpha protein were 0.093,0.889,and 0.158,respectively,siRNA-SIRT1 transfected SGC7901 for 8 hours and after 72 hours to test the relative quantity of SIRT1 protein expression average were 0.965,0.937,0.958,0.567,0.253,0.083 in control,BC-V,negative,siRNA-1,2,3 SIRT1,P-gp were 1.893,1.905,1.932,0.465,0.006,0.465 and Top-Ⅱ alpha were 0.09,0.07,0.073,0.085,0.168,0.085.MTT results showed that after SIRT1 protein expression was inhibited the SGC7901 proliferation has no obvious change in vitro and cell sensitivity to the chemotherapy drugs 5-Fu was increased significantly.Conclusion:SIRT1 expression in gastric cancer tissues and the expression of SIRT1 in gastric cancer tissue and cell carcinoma factors role,SIRT1 protein overexpression can promote P-gp protein expression lower Top-Ⅱ alpha protein expression in gastric cancer cells to chemotherapy of multiple drug resistance increase.

Research advances in tumor radiosensitization mediated by topoisomerase inhibitors / 中华放射医学与防护杂志

As anticancer drugs,topoisomerase inhibitors have been widely used in clinical practice,and their radiosensitivity has been gradually recognized.Many topoisomerase inhibitors are currently in pre-clinical and clinical studies.Several studies have shown that some topoisomerase inhibitors may be potential ideal radiosensitizers.However,the physico-chemical properties,toxicity and sensitization effects should be further investigated.

Resistance mechanism of Mycoplasma hominis to quinolones in Chengdu area / 中华检验医学杂志

Objective To detect the resistance of Mycoplasma hominis to quinolones in Chengdu area,explore resistance mechanism of topoisomerase gene gyrA, gyrB, parC and parE mutations associated with drug resistance and provide epidemiological data.Methods Mycoplasma hominis was identified by 16SrRNA gene sequencing technique and antibiotic susceptibility test was carried out by broth microdilution method.Resistance genes were amplified by PCR,whereas sequence alignment was analyzed by DNAMAN software and BLAST.Results Resistance rates of Mycoplasma hominis to ciprofloxacin, levofloxacin, moxifloxacin and gatifloxacin were 92.4%(61/66),87.9%(58/66),71.2%(47/66)and 66.7%(44/66),respectively.Totally 45 strains with different susceptibility to quinolones were screened for amplification and sequencing of topoisomerase genes, of which, 31 strains resistant to moxifloxacin and gatifloxacin harbored GyrA S153L amino acid mutation, 68.9%(31/45), 41 strains resistant to ciprofloxacin and levofloxacin harbored ParC S91I amino acid mutation, 91.1%(41/45).In addition, a new amino acid substitution of ParE A463S was found in 2 high-level resistant strains.No amino acid change was found in GyrB.Conclusions Resistance of Mycoplasma hominis to quinolones is closely associated with amino acid changes caused by mutations in gyrA and parC genes.Different quinolones have different targeting roles and high level resistance is associated with multiple gene mutations.

Inhibitory effects of lapachol on rat C6 glioma in vitro and in vivo by targeting DNA topoisomeraseⅠ and topoisomeraseⅡ / 中国药理学与毒理学杂志

OBJECTIVE Lapachol is a natural naphthoquinone compound that possesses extensive biological activities. The aim of this study is to investigate the inhibitory effects of lapachol on rat C6 glioma both in vitro and in vivo, as well as the potential mechanisms. METHODS The antitumor effect of lapachol was firstly evaluated in the C6 glioma model in Wistar rats. The effects of lapachol on C6 cell proliferation, apoptosis and DNA damage were detected by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS)/ phenazinemethosulfate (PMS) assay, hoechst 33358 staining, annexinⅤ-FITC/PI staining, and comet assay. Effects of lapachol on topoisomerase I (TOP I) and topoi?somerase Ⅱ (TOP Ⅱ) activities were detected by TOP Ⅰ and TOP Ⅱ mediated supercoiled pBR322 DNA relaxation assays and molecular docking. TOPⅠ and TOPⅡ expression levels in C6 cells were also determined. RESULTS High dose lapachol showed significant inhibitory effect on the C6 glioma in Wistar rats (P<0.05). It was showed that lapachol could inhibit proliferation, induce apoptosis and DNA damage of C6 cells in dose dependent manners. Lapachol could inhibit the activities of both TOPⅠ and Ⅱ. Lapachol-TOPⅠ showed relatively stronger interaction than that of lapachol-TOPⅡ in molecular docking study. Also, lapachol could inhibit TOPⅡ expression levels, but not TOPⅠ expression levels. CONCLUSION These results showed that lapachol could significantly inhibit C6 glioma both in vivo and in vitro, which might be related with inhibiting TOPⅠ and TOPⅡ activities, as well as TOPⅡ expression.

Proposal of Dual Inhibitor Targeting ATPase Domains of Topoisomerase II and Heat Shock Protein 90

There is a conserved ATPase domain in topoisomerase II (topo II) and heat shock protein 90 (Hsp90) which belong to the GHKL (gyrase, Hsp90, histidine kinase, and MutL) family. The inhibitors that target each of topo II and Hsp90 are intensively studied as anti-cancer drugs since they play very important roles in cell proliferation and survival. Therefore the development of dual targeting anti-cancer drugs for topo II and Hsp90 is suggested to be a promising area. The topo II and Hsp90 inhibitors, known to bind to their ATP binding site, were searched. All the inhibitors investigated were docked to both topo II and Hsp90. Four candidate compounds as possible dual inhibitors were selected by analyzing the molecular docking study. The pharmacophore model of dual inhibitors for topo II and Hsp90 were generated and the design of novel dual inhibitor was proposed.

Expressions of P53,topoisomerase Ⅱ and multi-drug resistance associated protein in tissues of colorectal cancer of patients combined with chronic schistosomiasis / 中华消化外科杂志

Objective To investigate the expressions of P53,topoisomeraseⅡ(TopoⅡ)and multidrug resistance associated protein(MRP)in tissues of colorectal cancer of patients combined with chronic schistosomiasis.Method The retrospective case-control study was adopted.The clinicopathological data of 338 colorectal cancer patients who were admitted to the Zhejiang Cancer Hospital between January 2008 and December 2010 were collected.Cancer tissue specimens from surgical resection were collected.Among 338 patients,80 were combined with chronic schistosomiasis and 258 were combined with non-chronic schistosomiasis.The expressions of P53,TopoⅡand MRP were dectected using immunohistochemistry(IHC).Ranked data were presented as percentage and analyzed using the non-parametric test.Results The negative,weak positive,positive and strong positive expressions of P53 were respectively 5.00％(4/80),87.50％(70/80),3.75％(3/80),3.75％(3/80)in tissues of colorectal cancer of patients combined with chronic schistosomiasis and 28.68％(74/258),19.38％(50/258),16.67％(43/258),35.27％(91/258)in tissues of colorectal cancer of patients combined with non-chronic schistosomiasis,with a statistically significant difference(Z=-2.962,P＜0.05).The negative,weak positive,positive and strong positive expressions of TopoⅡwere respectively 8.75％(7/80),51.25％(41/80),22.50％(18/80),17.50％(14/80)in tissues of colorectal cancer of patients combined with chronic schistosomiasis and 12.01％(31/258),55.43％(143/258),22.48％(58/258),10.08％(26/258)in tissues of colorectal cancer of patients combined with non-chronic schistosomiasis,with no statistically significant difference(Z=-1.551,P＞0.05).The negative,weak positive,positive and strong positive expressions of MRP were respectively 7.50％(6/80),40.00％(32/80),28.75％(23/80),23.75％(19/80)in issues of colorectal cancer of patients combined with chronic schistosomiasis and 24.42％(63/258),38.37％(99/258),24.03％(62/258),13.18％(34/258)in tissues of colorectal cancer of patients combined with non-chronic schistosomiasis,with a statistically significant difference(Z=-3.408,P＜0.05).Conclusion There are abnormal expressions of P53 and MRP in tissues of colorectal cancer of patients combined with chronic schistosomiasis,which may be involved in the hypothetical mechanism of chronic schistosomiasis inducing carcinogenesis of colorectal cancer.

Trimethoxy-benzaldehyde ciprofloxacin schiff base induces apoptosis in human hepatocarcinoma SMMC-7721 cells / 中国药学杂志

OBJECTIVE: To investigate the effect of 1-cyclopropyl-6-fluoro-7-(piperazin-1-yl)-3-[5-benzylsulfanyl-4-(3, 4, 5-trimethoxybenzylidene)amino-4H-1, 2, 4-triazol-3-yl]-quinolin-4(1H) -one (M27) on apoposis in hepatocarcinoma SMMC-7721 cells in vitro. METHODS: SMMC-7721 cells, colon adenocarcinoma cells(HCT-116) and leukemia cell line JURKET were treated by M27 with different concentrations for different time in vitro, the inhibitory effect of M27 and its precursor ciprofloxacin on the cell proliferation were examined by MTT assay. Cell apoptosis was determined by Hoechst 33258 fluorescence staining and TUNEL assay. The effect of M27 on topoisomerase II activity was measured using agarose gel electrophoresis by Plasmid pBR322 DNA as the substrate. Mitochondrial membrane potential(Δψm) was measured by high content screening imaging system. The p53, Caspase-9, Caspase-3, Caspase- 8, Bcl-2, Bax and cytochrome C protein expressions were determined by Western blotting analysis. RESULTS: The proliferation of the cancer cells was inhibited by M27 at 10-60 μmol·L-1 in time-and dose-dependent manner. Ciprofloxacin showed weak cytotoxicity against SMMC-7721 cell. SMMC-7721 cells treated by M27 with different concentrations for 24 h increased the percentage of apoptosis cells obviously (P < 0.05) with a decrease in the mitochondrial membrane potential. Compared with control group, M27 influenced obviously DNA topoisomerase II activity, stimulated DNA cleavage and inhibited DNA reunion mediated by topoisomerase II. In addition, M27 increased protein expression of p53, Bax, Caspase-8, Caspase-9, Caspase-3, as well as the cleaved activated forms of Caspase-9, Caspase-8 and Caspase-3 significantly, whereas the expression of Bcl-2 decreased. There was a significant increase of cytochrome C in the cytosol after 24 h of treatment with M27 and a decrease in the mitochondrial compartment. CONCLUSION: M27 as a fluoroquinolone derivative exerted potent anticancer activity through the mechanism of eukaryotic topoisomerase II poisoning. The growth inhibition is mainly mediated via apoptosis-associated mitochondrial dysfunction and regulation of Bcl-2 signaling pathways.

Ki-67 and DNA topoisomerase Ⅱ a predict survival in patients with primary hepatocellular carcinoma after liver transplantation / 中华肝胆外科杂志

Objective To investigate whether Ki-67 and DNA topoisomerase Ⅱ α (Topo Ⅱ α) are effective prognostic markers in patients with primary hepatocellular carcinoma (HCC) after liver transplantation.Methods This retrospective cohort study included 105 patients with HCC who underwent liver transplantation in a single center from 2001 to 2012.The demographic features,clinicopathological data,expressions of Topo I c and Ki-67 as detected by immunohistochemistry.The long-term survival and the potential prognostic factors,together with standard histologic parameters,were analyzed by univariate and multivariate analyses.Results A positive correlation was found between Topo II α and Ki-67 levels in HCC (r ＝ 0.469,P ＜ 0.01).Multivariate analyses showed that Ki-67 was an independent prognostic risk factor of recurrencefree survival (HR ＝ 2.296,P ＜ 0.05).The 5-year overall survival rate was related to tumor size (HR ＝ 1.743,P ＜ 0.05),AFP (HR ＝ 2.291,P ＜ 0.05),histological grade (HR ＝ 0.283,P ＜ 0.01),and high expressions of Ki-67 (HR ＝ 1.977,P ＜ 0.05) and Topo Ⅱ α levels (HR ＝ 1.883,P ＜ 0.05).The KaplanMeier analysis showed that there was a significant difference in the 5-year recurrence-free survival rate (40.4％ vs.57.6％) between patients with high and low expressions of Ki-67,which were significantly lower in the high Topo Ⅱ α expression patients (13.5％ vs.63.8％) (P ＜0.01).The 5-year overall survival rates were significantly lower in the high Ki-67 expression patients (12.7％ vs.61.1％,P ＜0.01) when compared with the low Ki-67 expression patients,which were significantly lower in the high Topo Ⅱ α-and Ki-67 expression patients (10.7％ vs.54.5％,P ＜0.01) than the low Topo Ⅱ α-or Ki-67 patients.Conclusions Ki-67 was associated with recurrence and metastasis in patients with primary hepatic carcinoma after liver transplantation.High expression of both Ki-67 and Topo Ⅱ α were associated with poor prognosis in these patients.

Expression of excision repair cross-complementing 1, topoisomeraseⅡ, ribonucleotide reductase M1,β3-tubulin and thymidylate synthase in lung cancer / 肿瘤研究与临床

Objective To analyze the expression characteristics of excision repair cross-complementing 1 (ERCC1), topoisomeraseⅡ (TOPOⅡ), ribonucleotide reductase M1 (RRM1), β3-tubulin and thymidylate synthase (TS) in lung cancer and their associations with the pathological types. Methods The immunohistochemical EnVision method was used to determine the expression of ERCC1, TOPOⅡ, RRM1,β3-tubulin and TS in 548 patients who were diagnosed as lung cancer from January 2011 to December 2014. Variance analysis was performed to analyze their expression characteristics among different pathological types and correlation. Results The expression positive rates of ERCC1, TOPOⅡ, RRM1, β3-tubulin and TS were 61.86 % (339/548), 91.06 % (499/548), 62.59 % (343/548), 73.18 % (401/548) and 70.44 % (386/548), respectively. The expression of ERCC1 was weak positive mostly (P<0.05), meanwhile the expression of TOPOⅡ was medium-strong positive mostly (P<0.05). In ERCC1 group, the positive rate of squamous cell carcinoma was higher than that of adenocarcinoma [57.39 % (167/291) vs. 42.61 % (124/291), P=0.000]. In weak positive of TOPOⅡ group, the proportion of adenocarcinoma was higher than that of squamous cell carcinoma [23.58 % (100/137) vs. 8.73 % (37/137), P=0.000]. In medium-strong positive of TOPOⅡ group, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma [47.41 % (201/287/) vs. 20.28%(86/287), P=0.000]. The expressions of ERCC1, TOPOⅡ, RRM1,β3-tubulin and TS were irrelevant (r=0.4, P=0.397). Conclusions The expressions of ERCC1 and TOPOⅡ are higher in squamous cell carcinoma than those in adenocarcinoma. The expression of ERCC1 is weak positive mostly, meanwhile the expression of TOPOⅡis medium-strong positive mostly. There is no correlation between them.

Tyrosyl-DNA phosphodiesterases: potential targets for cancer treatment / 药学学报

DNA topoisomerases-mediated DNA damages are generated from exogenous and endogenous effects, which need to be metabolized or repaired to maintain genome stability involving in many of repair enzymes. Tyrosyl-DNA phosphodiesterase 1 (TDP1) and tyrosyl-DNA phosphodiesterase 2 (TDP2) are two DNA repair enzymes discovered recently. TDP1 and TDP2 have the ability to hydrolyze the tyrosyl-phosphodiester bond of the phenol of tyrosine with 3'-and 5'-DNA end, respectively, which are contained in the metabolites of the damaged DNA mediated by topoisomerase 1 and topoisomerase 2, respectively. The abnormal activation and expression of TDP1 or TDP2 is the important reason for cancer development. Therefore, TDP1 and TDP2 have been regarded as potential targets in cancer therapy. In this review, we discuss the rationales of their potential as targets and development of their inhibitors together with topoisomerase poisons or DNA damaging agents.

Topoisomerase IB of Deinococcus radiodurans resolves guanine quadruplex DNA structures in vitro.

Deinococcus radiodurans genome contains a large number of guanine repeats interrupted by a few non-guanine bases, termed G motifs. Some of these G motifs were shown forming guanine quadruplex (G4) DNA structure in vitro. How is the formation and relaxation of G4 DNA regulated in the genome of D. radiodurans is not known and is worth investigating. Here, we showed that the topoisomerase Ib of D. radiodurans (DraTopoIB) could change the electrophoretic mobility of fast migrating intramolecular recF-G4 DNA into the slow migrating species. DraTopoIB also reduced the positive ellipticity in circular diachroism (CD) spectra of intramolecular recF-G4 DNA structures stabilized by K+. On the contrary, when DraTopoIB is incubated with G-motifs annealed without K+, it showed neither any change in electrophoretic mobility nor was ellipticity of the CD spectra affected. DNA synthesis by Taq DNA polymerase through G4 DNA structure was attenuated in the presence of G4 DNA binding drugs, which was abrogated by DraTopoIB. This implies that DraTopoIB could destabilize the G4 DNA structure, which is required for G4 drugs binding and stabilization. Camptothecin treatment inhibited DraTopoIB activity on intramolecular G4 DNA structures. These results suggested that DraTopoIB can relax intramolecular G4 DNA structure in vitro and it may be one such protein that could resolve G4 DNA under normal growth conditions in D. radiodurans.