吡咯烷二硫代氨基甲酸盐抑制NF-κB活化对HL-60细胞的化疗增敏作用

目的：探讨化疗诱导性核因子κB的活化机制及抗氧化抑制NF-κB活化对白血病细胞凋亡及化疗敏感性的影响。 方法： 采用间接免疫荧光方法和凝胶迁移率变动试验（EMSA）观察不同浓度的化疗药物单独或与抗氧化剂吡咯烷二硫代氨基甲酸盐（PDTC）联合作用于HL-60细胞后NF-κB的活化反应；运用流式细胞术和MTT试验比较NF-κB活化及活化抑制对HL-60细胞凋亡及化疗敏感性的影响。 结果： EMSA试验表明，柔红霉素（DNR）和足叶乙甙（VP-16）均呈剂量依赖性诱导NF-κB活化；RelA亚基位于细胞核进一步证实了NF-κB活化。PDTC呈剂量依赖性抑制诱导性NF-κB活化，当其浓度达到100 μmol/L时，NF-κB活化被完全抑制。比较PDTC干预前后细胞的凋亡反应，发现2.5 mg/L、5 mg/L、10 mg/L VP-16诱导的细胞凋亡指数分别由(5.34±0.62)%、(10.16±0.42)%、(17.32±1.15)%增至(8.97±0.81)%、(16.01±1.06)%、(22.96±1.33%)，且PDTC显著增强DNR及VP-16对HL-60细胞的生长抑制率(P<0.01)。 结论： 反应性氧中间产物介导化疗诱导性NF-κB活化，抗氧化抑制NF-κB活化可以增进HL-60细胞凋亡及化疗敏感性。     

Characterizing the influence of structure and route of exposure on the disposition of dithiocarbamates using toluene-3,4-dithiol analysis of blood and urinary carbon disulfide metabolites.

Differences in the toxicities observed for dithiocarbamates have been proposed to result from the influence of nitrogen substitution, oxidation state, and route of exposure. To better characterize the fate of dithiocarbmates in vivoas a function of structure and route of exposure, rats were administered equimolar doses of carbon disulfide (CS2), N-methyldithiocarbamate, pyrrolidine dithiocarbamate, N,N-diethyldithiocarbamate, or disulfiram daily for five days, either po or ip, and sequential blood samples obtained. Protein dithiocarbamates formed by the in vivo release of CS2, parent dithiocarbamate, and protein-bound mixed disulfides were assessed in plasma and hemolysate by measuring toluene trithiocarbonate generated upon treatment with toluene-3, 4-dithiol (TdT). To aid in determining the bioavailability of CS2 from the administered dithiocarbamates, the urinary CS2 metabolites, 2-thiothiazolidine-4-carboxylic acid (TTCA) and 2-thiothiazolidin-4-ylcarbonylglycine (TTCG), were also determined. The levels of TdT-reactive moieties detected depended upon both the compound administered and the route of exposure. Parent dithiocarbamates, with the exception of disulfiram, were eliminated from blood within 24 h; but protein associated TdT-reactive moieties persisted and accumulated with repeated exposure, regardless of the route of exposure. N-Methyldithiocarbamate demonstrated the greatest potential to produce intracellular globin modifications, presumably through its unique ability to generate a methylisothiocyanate metabolite. Urinary excretion of TTCA and TTCG was more sensitive than TdT analysis for detecting dithiocarbamate exposure, but TdT analysis appeared to be a better indicator of in vivo release of CS2 by dithiocarbamates than were urinary CS2 metabolites. These data suggest that CS2 is a more important metabolite, following oral exposure, than are other routes of exposure, e.g., inhalation or dermal. In addition, data also suggest that acid stability, nitrogen substitution, and route of exposure are important factors governing the toxicity observed for a particular dithiocarbamate.     

Effects of PDTC on the Proliferation and PCNA Expression of Human Retinal Pigment Epithelial Cells

Proliferative vitreoretinopathy (PVR) is oneof the most common eye diseases that couldlead tosevere vision i mpairment and tend to cause blind-ness .It has beenfound that the abnormal prolifer-ation of retinal pigment epithelium(RPE) plays akey role in the onset and development of PVR.Under pathologic status ,such as rhegmatogenousdetachment of retina and severe ocular trauma ,RPE cells may migrate and proliferate because ofthe sti mulations of cytokines or chemokines ,thusmay lead to path…     

广东地产中药中砷含量的测定

本文采用Ag- DDC分光光度法和新银盐法对广东地产13种中药材的砷含量进行测定,参考相关的限量标准,了解广东地产中药材砷的含量情况。结果发现石菖蒲的砷含量远远高于各项限量标准,其余12种中药材砷的含量较低。     

吡咯烷二硫代氨基甲酸盐对大鼠急性坏死性胰腺炎肝损伤的保护作用

目的:探讨核因子KB(NF-κB)抑制剂吡咯烷二硫代氨基甲酸盐(PDTC)对大鼠急性坏死性胰腺炎(ANP)的预防治疗作用。方法:大鼠80只随机分为正常对照组(Z)、胰腺炎组(Y)和干预纽.干预组又分为建模前1h PDTC干预组(A)、建模后1h PDTC干预组(B)和建模后6h干预组(C).干预组按不同时间ip PDTC.建模后6,12,24 h分批处死,临床全自动生化仪检测血清谷丙转氨酶(ALT)和淀粉酶(AMY),用凝胶迁移率改变分析法(EMSA)测定胰腺和肝脏中NF-κB的活性.同时观察胰腺和肝脏的病理改变.结果:正常大鼠组织中几乎测不到NF-κB的活性,与Z组比较,Y组胰腺和肝脏组织中6,12,24 h NF-κB活性分别明显增加(P<0.001).建模前1h,1h后使用PDTC,胰腺和肝脏组织中NF-κB活性均受到抑制(18.14±3.30,23.79±3.62 vs 24.82±4.57:10.68±2.51,13.83±2.70 vs 16.38±2.50;P<0.05),Y组血清ALT,AMY均高于对照组.病理学检查可以见到Y组和A,B,C组的胰腺和肝脏均有炎性改变,但A组较Y组明显为轻.结论:NF-κB的异常活化与SAP以及肝损伤有明显关系:PDTC对SAP时肝损伤的发生有一定的预防作用.     

Imaging prostate cancer (PCa) with [99mTc(CO)3]finasteride dithiocarbamate

This investigation aimed to modify finasteride ( 1 ) to finasteride dithiocarbamate ( 2 ) for subsequent synthesis of the rhenium analogue ( 3 ) and [^99mTc]tricarbonyl complexes ( 4 ), to assess its prostate cancer (PCa) targeting potential in a rat model. To validate the identity of ( 4) , reference ( 3) has been synthesized by using fac‐[Net₄]₂[ReBr₃(CO)₃] precursor and characterized by ¹H‐NMR, ¹³C‐NMR, ESI‐MS, and elemental analysis. The analogue ( 4) was synthesized by using fac‐[^99mTc(H₂O)₃(CO)₃]⁺ precursor, and its structure was confirmed by comparative HPLC by using ( 3) as a reference. Further, the suitability of ( 4) as a PCa imaging agent was investigated in vitro and in vivo. At room temperature, ( 4) had ≥99% radiochemical purity and remained ≥84% stable in serum. In preclinical studies, biodistribution of ( 4) in histopathologically established rat model showed adequately high in vivo uptake in the prostate attracting the possibility of using it for noninvasive imaging of PCa.     

Inhibition of EGFR autophosphorylation plays an important role in the anti-breast cancer efficacy of the dithiocarbamate derivative TM208

Aim： To investigate the effects of a novel dithiocarbamate derivative TM208 on human breast cancer cells as well as the pharmacoki- netic characteristics of TM208 in human breast cancer xenograft mice. Methods： Human breast cancer MCF-7 and MDA-MB-231 cells were treated with TM208 or a positive control drug tamoxifen. Cell pro- liferation was examined using SRB and colony formation assays. Cell apoptosis was analyzed with Annexin V-FITC/PI staining assay. Protein expression was examined with Western blot, ELISA and immunohistochemical analyses. MCF-7 breast cancer xenograft nude mice were orally administered TM208 （50 or 150 mg.k$1〈1-1） or tamoxifen （50 mg.kgl〈t-~） for 18 d. On d 19, the tumors were collected for analyses. Blood samples were collected from the mice treated with the high dose of TM208, and plasma concentrations of TM208 were measured using LC-MS/MS. Results： Treatment of MCF-7 and MDA-MB-231 cells with TM208 dose-dependently inhibited the cell proliferation and colony formation in vitro （the IC~o values were 36.38＋3.77 and 18.13＋0.76 pmol/L, respectively）. TM208 （20-150pmol/L） dose-dependently induced apoptosis of both the breast cancer cells in vitro. In MCF-7 breast cancer xenograft nude mice, TM208 administration dose-depend- ently reduced the tumor growth, but did not result in the accumulation of TM208 or weight loss. TM208 dose-dependently inhibited the phosphorylation of EGFR and ERK1/2 in both the breast cancer cells in vitro as well as in the MCF-7 xenograft tumor. Conclusion： Inhibition of EGFR autophosphorylation plays an important role in the anticancer effect of TM208 against human breast cancer.     

慢加急性肝衰竭小鼠肝组织组蛋白去乙酰化酶mRNA水平变化

目的 探讨组蛋白去乙酰化酶(HDAC) 抑制剂干预慢加急性肝衰竭(ACLF)小鼠肝组织组蛋白去乙酰化酶mRNA水平变化。方法 随机将小鼠分为7组,每组4只。A组为对照组,B组为模型组,C组为曲古抑菌素 A(TSA)处理组,D组为大剂量正丁酸钠处理组,E组为小剂量正丁酸钠处理组,F组为大剂量吡咯烷二硫代氨基甲酸(PDTC)处理组,G组为小剂量PDTC处理组,采用脂多糖联合D-Gal诱导小鼠肝衰竭模型。采用Q-PCR法检测小鼠肝组织Ⅰ类和Ⅱ类HDAC mRNA水平。结果 B组肝组织HDAC1mRNA、HDAC2mRNA、HDAC3mRNA和HDAC8mRNA水平分别为(1.7±0.2)、(1.7±0.3)、(1.9±0.6)和(2.6±0.7),而C组、D组、E组、F组和G组均显著降低(P<0.05);B组肝组织HDAC4mRNA、HDAC5mRNA、HDAC6mRNA、HDAC7mRNA、HDAC9mRNA和HDAC10mRNA水平分别为(0.6±0.2)、(6.3±0.9)、(3.4±0.8)、(2.8±1.0)、(6.5±1.1)和(0.4±0.1),而C组、D组、E组、F组和G组均显著降低(P<0.05)。结论 HDAC mRNA水平可能与机体乙酰化作用相关,可为应用组蛋白乙酰化调控治疗肝衰竭小鼠提供重要的理论依据。     

NF-κB抑制剂二硫代氨基甲酸吡咯烷提高卵巢癌细胞顺铂化疗的敏感性

目的:探讨核因子κB(nuclear factor kappa B, NF-κB)抑制剂二硫代氨基甲酸吡咯烷(pyrrolidine dithiocarbamate,PDTC)提高人卵巢癌SKOV-3细胞对顺铂(cisplatin)化疗敏感性的作用及其可能的机制.方法:用不同浓度PDTC联合顺铂在不同时间作用于卵巢癌SKOV-3细胞,MTT法观察药物作用对细胞生长的抑制,Western Blotting分析胞质内NF-κB 抑制蛋白α(inhibitor of NF-κB ,I-κBα)、胞核P65蛋白的表达;流式细胞术检测细胞凋亡.结果:PDTC(10～40 μmol/L)或顺铂(0.1～100 μg/ml )均明显抑制SKOV-3细胞的生长(P<0.05或P<0.01),并引起细胞的凋亡;小剂量PDTC(2.5、5 μmol/L)和顺铂(0.01 μg/ml)联合应用与单用顺铂比较,可明显增加细胞生长抑制率和细胞凋亡率(均P<0.05).单用顺铂组与对照组比较,胞质I-κBα蛋白减少而胞核P65蛋白增多,联合使用PDTC可逆转此现象.结论:小剂量PDTC可增强卵巢癌细胞对顺铂的敏感性,这一作用可能与PDTC增加I-κBα蛋白的表达而抑制P65蛋白进入核内有关.