UGT1A1*28基因多态性与伊立替康治疗晚期非小细胞肺癌的毒副反应及疗效的关系研究

目的探讨UGT1A1*28基因多态性与CPT-11治疗晚期NSCLC的毒副反应与疗效的关系。方法外周血检测2015年6月至2016年6月在九江市第一人民医院所收治的50例晚期NSCLC患者UGTIA1*28 TATA盒基因序列,并对所有50例患者接受CPT-11为基础化疗方案的患者出现的不良反应和近期疗效随访记录,比较不同基因型之间的差别。结果 50例晚期NSCLC患者中UGTIA1*28位点突变型可以增加发生3级以上腹泻(P=0.007)和3级以上血小板减少(41.7%VS 10.5%,P=0.027)的风险。结论在CPT-11化疗的患者中,UGTl Al*28基因型TA6/7,或TA7/7基因型可增加晚期NSCLC患者发生Ⅲ度以上腹泻及血小板减少的风险,然而不影响化疗的近期疗效。     

Resonant Formation of Strand Breaks in Sensitized Oligonucleotides Induced by Low‐Energy Electrons (0.5–9 eV)

Halogenated nucleobases are used as radiosensitizers in cancer radiation therapy, enhancing the reactivity of DNA to secondary low‐energy electrons (LEEs). LEEs induce DNA strand breaks at specific energies (resonances) by dissociative electron attachment (DEA). Although halogenated nucleobases show intense DEA resonances at various electron energies in the gas phase, it is inherently difficult to investigate the influence of halogenated nucleobases on the actual DNA strand breakage over the broad range of electron energies at which DEA can take place (<12 eV). By using DNA origami nanostructures, we determined the energy dependence of the strand break cross‐section for oligonucleotides modified with 8‐bromoadenine (^8BrA). These results were evaluated against DEA measurements with isolated ^8BrA in the gas phase. Contrary to expectations, the major contribution to strand breaks is from resonances at around 7 eV while resonances at very low energy (<2 eV) have little influence on strand breaks.     

Application of dispersive liquid–liquid microextraction for the preconcentration of eight parabens in real samples and their determination by high‐performance liquid chromatography

A simple and sensitive method for the simultaneous determination of eight parabens in human plasma and urine samples was developed. The samples were preconcentrated using dispersive liquid–liquid microextraction based on the solidification of floating organic drops and determined by high‐performance liquid chromatography with ultraviolet detection. The influence of variables affecting the extraction efficiency was investigated and optimized using Placket–Burman design and Box–Behnken design. The optimized values were: 58 μL of 1‐decanol (as extraction solvent), 0.65 mL methanol (as disperser solvent), 1.5% w/v NaCl in 5.0 mL of sample solution, pH 10.6, and 4.0 min centrifugation at 4000 rpm. The extract was injected into the high‐performance liquid chromatography system for analysis. Under the optimum conditions, the linear ranges for eight parabens in plasma and urine were 1.0–1000 ng/mL, with correlation coefficients above 0.994. The limit of detection was 0.2–0.4 and 0.1–0.4 ng/mL for plasma and urine samples, respectively. Relative recoveries were between 80.3 and 110.7%, while relative standard deviations were less than 5.4%. Finally, the method was applied to analyze the parabens in 98 patients of primary breast cancer. Results showed that parabens existed widely, at least one paraben detected in 96.9% (95/98) of plasma samples and 98.0% (96/98) of urine samples.     

5‐Methoxytryptophan‐dependent inhibition of oral squamous cell carcinoma metastasis

The metastatic status of oral cancer is highly associated with the overall survival rate of patients. Previous studies have revealed that the endogenous tryptophan metabolite 5‐methoxytryptophan (5‐MTP) can downregulate cyclooxygenase‐2 expression; suppress tumor proliferation, migration, and invasion; and reduce the tumor size. To improve the understanding of the molecular mechanisms involved in the regulation of 5‐MTP in the tumorigenesis of oral cancer, we conducted a comparative wound healing and transwell invasion assays. Our results revealed that 5‐MTP reduce oral cancer cell migration and invasion ability. In addition, the results of an in vivo assay demonstrated that the growth of primary tumors was significantly inhibited by 5‐MTP in OC3 oral cancer cells and in invasive OC3‐I5 oral cancer cells. Moreover, enlarged spleens were observed in OC3‐I5‐implanted severe combined immunodeficiency mice although 5‐MTP can inhibit spleen enlargement. Through comparative proteomics, we identified 32 differentially regulated protein spots by using 2D‐DIGE/MALDI‐TOF MS analyses. Some of the differentially regulated proteins such as amadillo‐repeat‐containing X‐linked protein 1, phosphoglycerate kinase 1, tropomyosin alpha‐1, and tropomyosin alpha‐4 may be associated with the 5‐MTP‐dependent inhibition of oral cancer growth and metastasis. We conclude that 5‐MTP plays a crucial role in inhibiting in vitro and in vivo cancer invasion and metastasis.     

膀胱癌分子标志物基质金属蛋白酶1的可溶性表达和尿液中的活性分析

通过分离人胚胎肾细胞(HEK293)中基质金属蛋白酶1(MMPl)基因序列,利用基因工程技术在大肠杆菌中表达并纯化了包涵体复性的MMP1;采用融合表达硫氧还蛋白(Thioredoxin,TrxA)的方法获得了可溶性的MMPl-TrxA复合蛋白,在TrxA蛋白和MMP1活性中心之间引入了一个肠激酶切割位点,通过酶切作用获得可溶性MMP1.明胶酶谱分析法对体外表达的MMP1和体内(尿液中)MMP1进行了分析比较.结果表明,TrxA蛋白能够显著提高MMP1的可溶性,且可溶性MMP1的明胶降解活性是复性的MMP1降解活性的1.54倍,与尿液中的MMP1的明胶酶降解活性相当.因此,明胶酶谱法是一种有效的、高灵敏的MMP1检测方法,所表达的可溶性MMP1为小分子探针筛选提供了更可靠的分子靶点.     

Antivitamins B12—A Structure‐ and Reactivity‐Based Concept

B₁₂‐antimetabolites are compounds that counteract the physiological effects of vitamin B₁₂ and related natural cobalamins. Presented here is a structure‐ and reactivity‐based concept of the specific ′antivitamins B₁₂′: it refers to analogues of vitamin B₁₂ that display high structural similarity to the vitamin and are ′locked chemically′ to prevent their metabolic conversion into the crucial organometallic B₁₂‐cofactors. Application of antivitamins B₁₂ to healthy laboratory animals is, thus, expected to induce symptoms of B₁₂‐deficiency. Antivitamins B₁₂ may, hence, be helpful in elucidating still largely puzzling pathophysiological phenomena associated with B₁₂‐deficiency, and also in recognizing physiological roles of B₁₂ that probably still remain to be discovered.     

Human Serum Albumin Conjugated Nanoparticles for pH and Redox‐Responsive Delivery of a Prodrug of Cisplatin

Platinum anticancer drugs are particularly in need of controlled drug delivery because of their severe side effects. Platinum(IV) agents are designed as prodrugs to reduce the side effects of platinum(II) drugs; however, premature reduction could limit the effect as a prodrug. In this work, a highly biocompatible, pH and redox dual‐responsive delivery system is prepared by using hybrid nanoparticles of human serum albumin (HSA) and calcium phosphate (CaP) for the Pt^IV prodrug of cisplatin. This conjugate is very stable under extracellular conditions, so that it protects the platinum(IV) prodrug in HSA. Upon reaching the acidic and hypoxic environment, the platinum drug is released in its active form and is able to bind to the target DNA. The Pt–HSA/CaP hybrid inhibits the proliferation of various cancer cells more efficiently than cisplatin. Different cell cycle arrests suggest different cellular responses of the Pt^IV prodrug in the CaP nanocarrier. Interestingly, this delivery system demonstrates enhanced cytotoxicity to tumor cells, but not to normal cells.     

Multivalent Polymer Nanocomplex Targeting Endosomal Receptor of Immune Cells for Enhanced Antitumor and Systemic Memory Response

We have designed and synthesized linear polymer‐based nanoconjugates and nanocomplexes bearing multivalent immunostimulatory ligands and also demonstrated that the synthetic multivalent nanocomplexes led to an enhanced stimulation of immune cells in vitro and antitumor and systemic immune memory response in vivo. We have developed hyaluronic acid (HA)‐based multivalent nanoconjugates and nanocomplexes for enhanced immunostimulation through the combination of multivalent immune adjuvants with CpG ODNs (as a TLR9 ligand) and cationic poly(L ‐lysine) (PLL; for the enhancement of cellular uptake). The multivalent HA‐CpG nanoconjugate efficiently stimulated the antigen‐presenting cells and the multivalent PLL/HA‐CpG nanocomplex also led to an enhanced cellular uptake as well as continuous stimulation of endosomal TLR9. The mice vaccinated with dendritic cells treated with the multivalent nanocomplex exhibited tumor growth inhibition as well as a strong antitumor memory response.