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Objective: To development the prognostic nomogram for malignant pleural mesothelioma (MPM). Methods: Two hundred and ten patients pathologically confirmed as MPM were enrolled in this retrospective study from 2007 to 2020 in the People's Hospital of Chuxiong Yi Autonomous Prefecture, the First and Third Affiliated Hospital of Kunming Medical University, and divided into training (n=112) and test (n=98) sets according to the admission time. The observation factors included demography, symptoms, history, clinical score and stage, blood cell and biochemistry, tumor markers, pathology and treatment. The Cox proportional risk model was used to analyze the prognostic factors of 112 patients in the training set. According to the results of multivariate Cox regression analysis, the prognostic prediction nomogram was established. C-Index and calibration curve were used to evaluate the model's discrimination and consistency in raining and test sets, respectively. Patients were stratified according to the median risk score of nomogram in the training set. Log rank test was performed to compare the survival differences between the high and low risk groups in the two sets. Results: The median overall survival (OS) of 210 MPM patients was 384 days (IQR=472 days), and the 6-month, 1-year, 2-year, and 3-year survival rates were 75.7%, 52.6%, 19.7%, and 13.0%, respectively. Cox multivariate regression analysis showed that residence (HR=2.127, 95% CI: 1.154-3.920), serum albumin (HR=1.583, 95% CI: 1.017-2.464), clinical stage (stage Ⅳ: HR=3.073, 95% CI: 1.366-6.910) and the chemotherapy (HR=0.476, 95% CI: 0.292-0.777) were independent prognostic factors for MPM patients. The C-index of the nomogram established based on the results of Cox multivariate regression analysis in the training and test sets were 0.662 and 0.613, respectively. Calibration curves for both the training and test sets showed moderate consistency between the predicted and actual survival probabilities of MPM patients at 6 months, 1 year, and 2 years. The low-risk group had better outcomes than the high-risk group in both training (P=0.001) and test (P=0.003) sets. Conclusion: The survival prediction nomogram established based on routine clinical indicators of MPM patients provides a reliable tool for prognostic prediction and risk stratification.
Subject(s)
Humans , Mesothelioma, Malignant , Prognosis , Nomograms , Retrospective Studies , Proportional Hazards ModelsABSTRACT
Background Natural product sanguinarine chloride (SC) can significantly alleviate liver fibrosis and acute liver injury in mice, but whether it has a protective effect on mouse liver injury caused by sodium arsenite (SA) has not been studied. Objective To verify if SC may present preventive and therapeutic effects on SA-induced liver injury in mice. Methods A total of 140 SPF male Kunming mice were randomly divided into two sub-studies, which included a prevention sub-study and a treatment sub-study. In each sub-study, a blank group (normal saline), a model group (5 mg·kg−1 SA), and a positive control group (11.375 mg·kg−1 bicyclol and 182 mg·kg−1 glutathione), as well as SC low, medium, and high dose groups (25, 50, and 100 mg·kg−1) were arranged with 10 mice in each group. In the prevention sub-study, the blank group was given normal saline, the model group was given SA, and the other groups (the SC low, medium, and high dose groups and the positive control group) were given the corresponding treatment 30 min before gavage of SA, once a day, for 28 d. In the treatment sub-study, except for the blank group which was given normal saline, the other groups were given SA for 28 d, then the model group was given normal saline, and the other groups were given the corresponding treatment every day for 28 d. After the experiment, the mice were sacrificed to evaluate selected physiological and biochemical indicators in serum and liver tissue and to observe histopathological changes after HE staining. Results In either sub-study of preventive effect or treatment effect: compared with the blank group, body weight, liver weight, liver coefficient, as well as serum alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), malondialdehyde (MDA), glutathione peroxidase (GSH), and superoxide dismutase (SOD) among all SC groups were not significantly different (P>0.05); but compared with the model group, the SC groups showed increased body weight (P<0.01), decreased liver weight and liver coefficient (P<0.01), reduced ALT, AST, TBIL, and MDA (P<0.05 or P<0.01), and increased GSH and SOD with (P<0.05 or P<0.01) or without significance; compared with the positive control group, no differences were found in the above indicators (P＞0.05). The result of histopathological evaluation showed that the SC groups had a clear liver lobule structure, neatly arranged hepatic cords, and less infiltration of inflammatory cells. Conclusion SC has both preventive and therapeutic effects on SA-induced liver injury in mice.
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Benign prostatic hyperplasia (BPH) is a common disease in elderly men, and transurethral laser prostatectomy (TULP) has been widely used in the clinic to remove bladder outlet obstruction caused by BPH. Previous animal models for wound repair after prostatectomy have many limitations, and there have been no previous reports of a mouse model of TULP. Therefore, this study aimed to establish a novel mouse model of TULP. Twelve healthy adult Kunming (KM) mice received transurethral laser vaporization prostatectomy with a 200-μm thulium laser. The mice were sacrificed, and wound specimens from the prostatic urethra and bladder neck were harvested at 1 day, 3 days, 5 days, and 7 days after surgery. Hematoxylin-eosin (HE) and immunohistochemistry were applied to confirm the establishment of the mouse TULP model. One day after the surgery, urothelium expressing uroplakin (UPK) was absent in the urethral wound site, and a large number of necrotic tissues were found in the wound site. There was no UPK-positive urothelium in the wound 3 days after surgery. At 5 days after surgery, monolayer urothelium expressing UPK was found in the wound site, indicating that the re-epithelization of the wound had been completed. On the 7th day after surgery, there were multiple layers of urothelium with UPK expression, indicating that the repair was completed. It is feasible to establish a mouse TULP model by using a microcystoscope system and a 200-μm thulium laser.
Subject(s)
Aged , Animals , Humans , Male , Mice , Laser Therapy , Prostatectomy , Prostatic Hyperplasia/surgery , Thulium , Transurethral Resection of ProstateABSTRACT
OBJECTIVE：To study the effe cts of the water extract from Carpesium cernuum （AECC）on the proliferation ， metastasis and invasion of prostate cancer PC 3 cells. METHODS ：Cells were divided into control group and different concentration groups of AECC （5，10，20，40，80 μg/L），and then treated with relevant medicine or medium for different time （24，48，72 h）. The survival rates of cells were detected. Cells were divided into control group ，and AECC low ，medium and high concentration groups（20，40，80 μg/L）. After cultured for 24 h，Hoechst 33258 staining and flow cytometry were used to detect the apoptosis of cells. The number of cell metastasis and invasion were detected by Transwell assay. RT-qPCR and Western blot assay were applied to detect the mRNA and protein expression of β-catenin signaling pathway related migration and apoptosis proteins （β-catenin， MMP-7，c-Myc，caspase-3，Bcl-2 and Bax ）in AECC low and medium concentration groups. RESULTS ：With the increase of the concentration and culture time ，the survival rates of cells in AECC different concentration groups were significantly lower than control group （P＜0.05 or P＜0.01），and showed a decreasing trend. Compared with control group ，the early apoptosis rate （except the medium concentration group ）and the number of cell metastasis and invasion in AECC groups ，the mRNA and protein expression of MMP- 7，c-Myc（except for the low concentration group ）and Bcl- 2（except for mRNA of the low concentration group）in AECC low and medium concentration groups were decreased significantly （P＜0.05 or P＜0.01）. Late apoptosis rate of AECC groups ，the mRNA and protein expression of β-catenin，caspases-3（except for the low concentration group ），Bax（except for mRNA of the low concentration group ）in AECC low and medium concentration groups were increased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS ：AECC could inhibit the proliferation ，metastasis and invasion of PC 3 cells；the mechanism of which may be associated with regulating the expression of β-catenin signaling pathway related migration and apoptotic factors.
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OBJECTIVE: To construct the RNA interference(RNAi) lentiviral vector of suppressor of variegation 3-9 homolog 1(Suv39 h1) and verify its interfering efficiency by transfecting it to the bone marrow-derived mesenchymal stem cells(BMSCs). METHODS: The oligonucleotides of RNA plasmid were designed and synthesized according to the gene sequence of Suv39 h1 and short hairpin RNA design principles. Three kinds of LV-Suv39 h1-RNAi recombinant plasmids with different lentivirus knockdown targets(KD1, KD2 and KD3) were constructed. After identification by restriction analysis and sequencing, the packaged lentivirus vectors with the three kinds of Suv39 h1 gene were transfected into rat BMSCs at logarithmic growth stage, and were named KD1, KD2 and KD3 transfection groups. The control group was transfected with the negative control virus. After 72 hours transfection, the transfection efficiency was evaluated, and the relative mRNA levels of Suv39 h1 were determined by quantitative real-time polymerase chain reaction(qPCR). RESULTS: Sequencing analysis demonstrated that three kinds of LV-Suv39 h1-RNAi recombinant plasmids were constructed correctly. The results of transfection efficiency evaluation showed that more than 80.00% green fluorescence was expressed in the BMSCs transfected with the three lentiviral vectors with a multiplicity of infection of 20. These results indicated that lentivirus was successfully constructed and transfection efficiency was high. The results of qPCR showed that the relative expression of Suv39 h1 mRNA in BMSCs of KD1, KD2 and KD3 transfection groups was lower than that in the control group(all P<0.05), and the relative expression of Suv39 h1 mRNA in KD1 and KD3 transfection groups was lower than that in KD2 transfection group(both P<0.05). However, there was no significant difference in the relative expression of Suv39 h1 mRNA between KD1 and KD3 transfection groups(P>0.05). CONCLUSION: The constructed lentiviral vector with low expression of Suv39 h1 was constructed successfully. This vector can be expressed in rat BMSCs, which lays a foundation to study the effect of Suv39 h1 gene in acute myeloid leukemia.
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We conducted the present study to assess the correlation of the prostatic anatomical parameters, especially the ratio of peripheral zone thickness and transitional zone thickness, with clinical and uroflowmetry characteristics suggestive of benign prostate hyperplasia (BPH). A total of 468 consecutive patients with a detailed medical history were identified. All patients were evaluated by scoring subjective symptoms with the International Prostate Symptom Score (IPSS) and quality of life (QoL). The prostatic anatomical parameters were measured using transrectal ultrasonography, and postvoid residual urine and maximum flow rate (Q
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Objective: TO synthesize novel berberine derivatives with a variety of physiological activities,and study their antitumor activity and acetylcholinesterase inhibitory activity. Method: Berberines with a variety of physiological activities were pieced together isohydroxamic acid,o-phenylenediamine,and sulfhydryl pharmacophore with effects in inhibiting histones and removing acetylases. Totally 7 novel berberine derivatives were obtained by means of organic synthesis. The structures of these derivatives were characterized and confirmed by 1H-NMR,13 C-NMR and MS spectral data.Thiazolyl blue tetrazolium bromide(MTT) method was used in the determination of the cytotoxic activity of HCT116,HepG2,HeLa and CCRF-CEM human cancer cell lines in vitro. Ellman method was used to reveal the inhibitory activities of acetylcholinesterase and butyrylcholinesterase. Result: The results showed that the berberine derivatives containing methyl ketone had good antitumor and acetylcholinesterase inhibitory activities. The results demonstrated that compound 5b had the highest anti-proliferative activity against CCRF-CEM cell line and the acetylcholinesterase inhibitory activities, with IC50=1.48 μmol · L-1 and IC50=0.38 μmol · L-1,respectivly. Conclusion: This paper provides a reference for the synthesis and biological evaluation of this kind of alkaloid derivatives. Compound 5b is a promising candidate drug and worth further study.
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To investigate the effects of thanatos-associated protein 11 (THAP11) on the proliferation and apoptosis of esophageal cancer cell and the underlying mechanism. Methods: Expression of THAP11 in human esophageal epithelial cells (Het-1A) and esophageal cancer cells (Eca109, TE-1, Ec 9706) were detected by Western blotting. Esophageal cancer TE-1 cells were divided into 3 groups: a normal control (NC) group, a negative control (LV-NC) group and a THAP11 (LV-THAP11) group. Then the cell proliferation were detected by MTT assay, cell apoptosis were detected by flow cytometry, caspase-3 and caspase-9 levels were detected by caspases kits. Ubiquitination of p53 was determined in esophageal cancer TE-1 cells. Results: Expression of THAP11 was reduced in esophageal cancer cells compared with human esophageal epithelial cells (P<0.05). After transfection with LV-THAP11 in TE-1 cells, cell viability was reduced (P<0.05), while apoptosis rate and caspase-3 and caspase-9 levels were increased (P<0.05), indicating that THAP11 inhibited growth of esophageal cancer cells. In addition, the THAP11 increased the levels of p53 (P<0.05) and inhibited the ubiquitination of p53 regulated by MDM2. Conclusion: THAP11 may inhibit the proliferation of esophageal cancer cells by inhibiting ubiquitination of p53.
Subject(s)
Humans , Apoptosis , Cell Line, Tumor , Cell Proliferation , Esophageal Neoplasms , Repressor Proteins , Metabolism , Tumor Suppressor Protein p53 , UbiquitinationABSTRACT
BACKGROUND: The most common soft liners currently used in the clinic are silicone rubbers and acrylics, but both of them have deficiencies. Therefore, the development of soft lining materials with stability, excellent performance, and antibacterial properties is of important clinical significance. OBJECTIVE: To prepare a soft lining material with high elasticity on the basis of excellent characteristics of Eucommia ulmoides gum, and to preliminarily explore its water absorption and solubility. METHODS: The basic formula was made based on the existing formula of elastic Eucommia ulmoides gum and medical rubber, in combination with the specific requirements of denture lining materials. The ratio of Eucommia ulmoides to butadiene rubber was set to be 10:90, 30:70, 50:50, 70:30 and 90:10, and the new Eucommia ulmoides gum composite soft denture liners were then prepared. Acrylate self-curing soft lining material and Silagum silicone rubber denture soft lining material served as controls. Afterwards, the samples were put into distilled water or artificial saliva for 7 and 30 days, and the value of water absorption and water solubility were calculated. RESULTS AND CONCLUSION: (1) In the artificial saliva for 7 and 30 days, the water absorption rate and solubility of samples in different ratio groups were close to those in the Silagum group, but extremely lower than those in the acrylate group. (2) In the distilled water for 7 and 30 days, the water absorption rate and solubility of samples in different ratio groups were close to those in the Silagum group, but extremely lower than those in the acrylate group. (3) The water absorption rate and solubility of the acrylate group were significantly higher than those in the other groups at 7 and 30 days of immersion in the artificial saliva or distilled water (P < 0.05). (4) After 7 and 30 days of immersion, the water absorption rate of the same sample in the artificial saliva was significantly lower than that in the distilled water. Wile at 7 days of immersion, the samples in the 30:70 and 50:50 groups showed a lower solubility in the artificial saliva than in the distilled water (P < 0.05), and at 30 days of immersion, the samples in the 30:70, 50:50, 70:30 and 90:10 groups showed a lower solubility in the artificial saliva than in the distilled water (P < 0.05). (5) In the artificial saliva, there was no significant difference in the solubility in the 50:50 and 70:30 groups at 7 and 30 days of immersion (P> 0.05), while the solubility in the other groups exhibited significant differences at different observational times (P < 0.05). In the distilled water, there was no significant difference in the solubility in the 10:90 and 30:70 groups at 7 and 30 days of immersion (P> 0.05), while the solubility in the other groups exhibited significant differences at different observational times (P < 0.05). To conclude, the water absorption of Eucommia ulmoides gum composite soft denture liner is close to Silagum, but significantly less than that of acrylate soft lining materials, and the solubility remains at a very low level.
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Objective:To investigate the clinical significance of bone metabolism indexes and human leukocyte antigen B27 (HLA-B27)in ankylosing spondylitis(AS)and analyze their diagnostic value. Methods:The subjects were 94 cases of AS patients,239 cases with other diseases and 80 healthy controls, and the results were retrospectively surveyed. Results:In the AS group, the concentration of the β-collagen specific sequence (β-CTX ) was higher ( P<0. 05 ) while the concentrations of osteocalcin ( OC ) , 25-hydroxyvitamin D[25-(OH)D] and parathyroid hormone(PTH)were lower than those in the control group. In the AS group,there was a positive correlation between the concentration of C-reactive protein(CRP)and β-CTX(P<0. 01),and the concentration of CRP was negatively correlated with the concentration of 25-(OH)D(P<0. 05). However,the concentrations of other bone metabolic indexes had no correlation with the concentration of CRP(P<0. 05). The positive rate of HLA-B27 in the AS group was significantly higher than that in other groups(P<0. 05),and HLA-B27 had highly sensitive and specific in the diagnosis of AS. In the AS group,the sensitivity of the concentration of 25-( OH) D was higher than β-CTX,while its specificity was lower than β-CTX. Conclusion:Bone metabolic indexes have great value in early screening and clinical diagnosis of AS,especially β-CTX and 25-( OH) D were more obvious.
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AIM:To investigate the effect of piceatannol on the viability, and the abilities of migration and invasion in the prostate cancer cells.METHODS:DU145 cells were treated with piceatannol at different doses (0, 5, 10, 20, 40 and 80 μmol/L) for different time (12, 24, 36 and 48 h) as indicated.The cell viability was assessed by CCK-8 assay.The migration and invasion abilities of the cells were analyzed by wound healing assay and Transwell assay, respectively.The protein levels of p-JAK2 and p-STAT3 were detected by Western blot.RESULTS:Piceatannol dose-dependently decreased the cell viability.After treatment with piceatannol, the abilities of migration and invasion of the cells were significantly inhibited.Moreover, treatment with piceatannol resulted in marked decreases in the protein levels of p-JAK2 and p-STAT3.CONCLUSION:Piceatannol inhibits the viability, migration and invasion of the prostate cancer cells via regulating the JAK2/STAT3 signaling pathway.
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Objective To understand the distribution and drug resistance dynamic status of common pathogens isolated from neurocranial surgical inpatients to provide a basis for clinically rational use of antimicrobial drugs .Methods A total of 413 strains of pathogenic bacteria isolated from neurocranial surgical inpatients from January 2013 to June 2016 were performed the identifica-tion and drug susceptibility test by using the Compact Vitek-2 automatic bacterial identificantion analyzer and the drug susceptibility test results were analyzed by using the WHONET5 .6 software .Results The commonest pathogenic bacteria were 90 strains of Pseudomonas aeruginosa ,69 strains of Klebsiella pneumonia ,52 strains of Escherichia coli ,50 strains of Acinetobacter baumannii and 37 strains of Staphylococcus Aureus .The common bacteria were resistant to many antibiotic drugs .The detection rate of me-thicillin-resistant Staphylococcus Aureus(MRSA) was 54 .1% ,no vancomycin-resistant Staphylococcus Aureus was found .Conclu-sion Clinicians should concern about the common pathogens and their drug resistance in their department ,rationally select antibac-terial drugs ,increase the curative effect and reduce the occurrence of bacterial drug resistance .
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Objective:To investigate the clinical significance of bone metabolism indexes and human leukocyte antigen B27 (HLA-B27)in ankylosing spondylitis(AS)and analyze their diagnostic value. Methods:The subjects were 94 cases of AS patients,239 cases with other diseases and 80 healthy controls, and the results were retrospectively surveyed. Results:In the AS group, the concentration of the β-collagen specific sequence (β-CTX ) was higher ( P<0. 05 ) while the concentrations of osteocalcin ( OC ) , 25-hydroxyvitamin D[25-(OH)D] and parathyroid hormone(PTH)were lower than those in the control group. In the AS group,there was a positive correlation between the concentration of C-reactive protein(CRP)and β-CTX(P<0. 01),and the concentration of CRP was negatively correlated with the concentration of 25-(OH)D(P<0. 05). However,the concentrations of other bone metabolic indexes had no correlation with the concentration of CRP(P<0. 05). The positive rate of HLA-B27 in the AS group was significantly higher than that in other groups(P<0. 05),and HLA-B27 had highly sensitive and specific in the diagnosis of AS. In the AS group,the sensitivity of the concentration of 25-( OH) D was higher than β-CTX,while its specificity was lower than β-CTX. Conclusion:Bone metabolic indexes have great value in early screening and clinical diagnosis of AS,especially β-CTX and 25-( OH) D were more obvious.
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The chemical components in the decoctions of Chinese herbal medicines are not always the same as those in the crude herbs because of the insolubility or instability of some compounds. In this work, a high-performance liquid chromatography [HPLC] coupled with electrospray ionization [ESI] tandem mass spectrometry method was developed to explore dynamic variation patterns of aconitum alkaloids in Fuzi during the process of decocting aconite root. The fragmentation patterns of aconitum alkaloids using ESI and collision-induced dissociation [CID] techniques were reported. This assay method was validated with respect to linearity [r[2] > 0.9950], precision, repeatability, and accuracy [recovery rate between 94.6 and 107.9%].The result showed that the amounts of aconitum alkaloids in the decoction at different boiling time varied significantly. In the decoction process, the diester- type alkaloids in crude aconite roots have transformed into Benzoylaconines or aconines
Subject(s)
Alkaloids , Plant Extracts , Chromatography, High Pressure Liquid , Tandem Mass Spectrometry , Phytotherapy , Drugs, Chinese HerbalABSTRACT
OBJECTIVE: To preliminary investigate the effects of sodium valproate on the proliferation, the apoptosis and the cell cycle distribution and expression of p21 of lung cancer cell line H1299 in vitro, and to explore its possible mechanism.
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To establish a fast sensitive, reproducible LC-MS/MS method to study pharmacokinetic properties of THC, and compare relative bioavailability of THC and its solid dispersion in mice. 200 mice were divided randomly into two groups, and administered orally with THC and THC-solid dispersion after fasting (calculate on THC:400 mg x kg(-1)), used HPLC-MS/MS method to determine the THC concentration of each period at the following times: baseline ( predose ), 15, 30, 45 min, 1, 1.5, 2, 3, 4, 6, 24 h after dosing. Calculating the pharmacokinetic parameters according to the C-t curv, and then use the Phoenix WinNonlin software for data analysis. The calibration curves were linear over the range 9.06-972 microg x L(-1) for THC (R2 = 0.999). The limit of detection (LOD) was 0.7 microg x L(-1), respectively. The average extraction recoveries for THC was above 75%, The methodology recoveries were between 79% and 108%. The intra-day and inter-day RSD were less than 13%, the stability test showed that the plasma samples was stable under different conditions (RSD < 15%). The precision, accuracy, recovery and applicability were found to be adequate for pharmacokinetic studies. Pharmacokinetic parameters of THC and THC-solid dispersion orally to mice shows as fllows: T(max), were 60 and 15 min, AUC(0-t) were 44 500.43 and 57 497.81 mg x L(-1) x min, AUC(0-infinity) were 51 226.00 and 68 031.48 mg x L(-1) x min, MRT(0-infinity) were 596.915 6, 661.747 7 min, CL(z)/F were 0.007 809 and 0.005 88 L x min(-1) x kg(-1). Compared with THC, the MRT and t1/2 of the THC-solid dispersion were all slightly extended, the t(max) was significantly reduced, AUC(0-24 h), AUC(0-infinity) and C(max) were all significantly higher, the relative bioavailability of THC-solid dispersion is 1.34 times of THC. The results of the experiment shows that the precision, accuracy, recovery and applicability were found to be adequate for the pharmacokinetic studies. After oral administration to mice, the relative bioavailability of THC-solid dispersion show significant improvement compared to THC.
Subject(s)
Animals , Female , Male , Mice , Administration, Oral , Biological Availability , Dronabinol , Chemistry , PharmacokineticsABSTRACT
This article was aimed to study the chemical constituents in Tragopogon porrifolius L. and their activities by pharmacological experiment in order to provide evidences in the further development of the usage of this medical resource. Under the guidance of pharmacological activities screening results, compounds were isolated by repeated silica gel, macroporous resin column chromatography and HPLC. Their structures were identified by means of UV, IR, MS, NMR and other chemical evidences. The results showed that T. porrifolius L. (i.e., n-butanol extraction part) can increase survival time of mice in the oxygen-lacking state (P < 0.05). Two compounds of biological alkaloids, which were identified as 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (Ⅰ) and adenine (II), were isolated. It was concluded that compound Ⅰ and II were obtained from T. porrifolius L. for the first time.
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<p><b>OBJECTIVE</b>To study the effect of fleroxacin (FLRX) on biological properties of Bloom (BLM) helicase catalytic core (BLM642-1290 helicase) in vitro and the molecular mechanism of interaction between the two molecules.</p><p><b>METHODS</b>DNA-binding and unwinding activities of BLM642-1290 helicase were assayed by fluorescence polarization and gel retardation assay under conditions that the helicase was subjected to different concentrations of FLRX. Effect of FLRX on helicase ATPase activity was analyzed by phosphorus-free assay based on a colorimetric estimation of ATP hydrolysis-produced inorganic phosphate. Molecular mechanism of interaction between the two molecules was assayed by ultraviolet and fluorescence spectra.</p><p><b>RESULTS</b>The DNA unwinding and ATPase activities of BLM642-1290 helicase were inhibited whereas the DNA-binding activity was promoted in vitro. A BLM-FLRX complex was formed through one binding site, electrostatic and hydrophobic interaction force. Moreover, the intrinsic fluorescence of the helicase was quenched by FLRX as a result of non-radioactive energy transfer. The biological activity of helicase was affected by FLRX, which may be through an allosteric mechanism and stabilization of enzyme conformation in low helicase activity state, disruption of the coupling of ATP hydrolysis to unwinding, and blocking helicase translocation on DNA strands.</p><p><b>CONCLUSION</b>FLRX may affect the biological activities and conformation of BLM642-1290 helicase, and DNA helicase may be used as a promising drug target for some diseases.</p>
Subject(s)
DNA , Metabolism , Fleroxacin , Pharmacology , Nucleic Acid Synthesis Inhibitors , Pharmacology , RecQ Helicases , Metabolism , Spectrometry, Fluorescence , Spectrophotometry, UltravioletABSTRACT
<p><b>OBJECTIVE</b>Bloom's syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene (encoding a BLM helicase) may form a structure of the etiology of this disease. As a global pollutant, mercury poses a major threat to human health. The current study was conducted to elucidate the effects of Hg(2+) on the structure and activity of BLM642-1290 recombinant helicase, and to further explore the molecular mechanisms of mercury toxicity to the DNA helicase.</p><p><b>METHODS</b>The effects of Hg(2+) on biological activity and structure of BLM642-1290 recombinant helicase were determined by fluorescence polarized, ultraviolet spectroscopic, and free-phosphorus assay technologies, respectively.</p><p><b>RESULTS</b>The helicase activity, the DNA-binding activity, and the ATPase activity of BLM642-1290 recombinant helicase were inhibited by Hg(2+) treatment. The LMCT (ligand-to-metal charge transition) peaks of the helicase were enhanced with the increase of the Hg(2+) level. The LMCT peaks of the same concentration of helicase gradually increased over time.</p><p><b>CONCLUSION</b>The biological activity of BLM642-1290 recombinant helicase is inhibited by Hg(2+) treatment. The conformation of the helicase is significantly altered by Hg(2+). There exist two binding sites between Hg(2+) and the helicase, which are located in the amino acid residues 1063-1066 and 940-944 of the helicase, respectively.</p>
Subject(s)
Humans , Adenosine Triphosphatases , Metabolism , Base Sequence , DNA Primers , Fluorescence Polarization , Mercury , Toxicity , Protein Conformation , RecQ Helicases , Chemistry , Metabolism , Recombinant Proteins , Chemistry , Metabolism , Spectrophotometry, Ultraviolet , Structure-Activity RelationshipABSTRACT
The effect of plant hormones on the growth of lichen-forming fungi (LFF) was evaluated. The use of 2,3,5-triiodobenzoic acid and indole-3-butyric acid resulted in a 99% and 57% increase in dry weight of the lichen-forming fungus Nephromopsis ornata. The results suggest that some plant hormones can be used as inducers or stimulators of LFF growth for large-scale culture.