铁皮枫斗西洋参胶囊对小鼠免疫调节功能的影响

目的:探讨铁皮枫斗西洋参胶囊对小鼠免疫调节功能的影响。方法:选择低、中、高剂量的铁皮枫斗西洋参胶囊(58 mg/kg、117 mg/kg和350 mg/kg),采用免疫毒理学方法研究对小鼠免疫功能的调节作用。结果:每天补充中、高剂量的铁皮枫斗西洋参,30 d后小鼠的细胞免疫功能、体液免疫功能、单核—巨噬细胞吞噬功能和NK细胞活性明显增强(P<0.05,P<0.01)。结论:铁皮枫斗西洋参胶囊能增强小鼠的免疫调节功能。     

Effects of mycophenolic acid–glucosamine conjugates on the base of kidney targeted drug delivery

Mycophenolic acid has played an important role in treating immunosuppression and autoimmune diseases. Nevertheless, the agent needs a high dosage in treatment, following some side effects. To tackle this problem, in this study, mycophenolic acid–glucosamine conjugate (MGC), modified by 2-glucosamine, was synthesized to achieve kidney targeting and improved drug efficacy with a lower dosage. ¹H NMR, ¹³C NMR and HRMS spectroscopy were used to verify the conjugate whose stability was good in vitro. The transport of MGC by human proximal renal tubular epithelial HK-2 cells was temperature-, time-, concentration-dependent and saturable, suggesting the involvement of carrier-mediated uptake. In addition, the cellular uptake of MGC dropped substantially with the inhibition of megalin receptor. The specific tissue distribution indicated the commendable renal-targeting capability of MGC. The concentration of MGC was improved in the kidney except for other tissues, about 6.76 times higher than that of MPA. Further, the bioavailability of MGC in plasma decreased as compared with mycophenolic acid. Moreover, therapeutic effect of MGC was enhanced significantly compared with MPA in the acute kidney injury model. All the findings suggested the potential of mycophenolic acid–glucosamine conjugate in kidney targeted drug delivery.     

Identification of mutations associated with acquired resistance to sunitinib in renal cell cancer

Sunitinib is one of the most widely used targeted therapeutics for renal cell carcinoma (RCC), but acquired resistance against targeted therapies remains a major clinical challenge. To dissect mechanisms of acquired resistance and unravel reliable predictive biomarkers for sunitinib in RCC, we sequenced the exons of 409 tumor-suppressor genes and oncogenes in paired tumor samples from an RCC patient, obtained at baseline and after development of acquired resistance to sunitinib. From newly arising mutations, we selected, using in silico prediction models, six predicted to be deleterious, located in G6PD, LRP1B, SETD2, TET2, SYNE1, and DCC. Consistently, immunoblotting analysis of lysates derived from sunitinib-desensitized RCC cells and their parental counterparts showed marked differences in the levels and expression pattern of the proteins encoded by these genes. Our further analysis demonstrates essential roles for these proteins in mediating sunitinib cytotoxicity and shows that their loss of function renders tumor cells resistant to sunitinib in vitro and in vivo. Finally, sunitinib resistance induced by continuous exposure or by inhibition of the six proteins was overcome by treatment with cabozantinib or a low-dose combination of lenvatinib and everolimus. Collectively, our results unravel novel markers of acquired resistance to sunitinib and clinically relevant approaches for overcoming this resistance in RCC.     

DCC和C-erbB-2在子宫颈癌中的表达及临床意义

目的:探讨DCC、C-erbB-2基因在子宫颈癌中的表达及其在宫颈癌发生、发展中的作用,及作为肿瘤标记物用于临床筛查和判断预后的临床意义。方法:应用免疫组织化学法检测22例宫颈鳞癌,10例CINⅡ～Ⅲ及20例慢性宫颈炎(对照组)组织中的DCC和C-erbB-2基因表达水平,并比较其表达差异。结果:DCC在慢性宫颈炎、宫颈癌组织中的阳性表达率分别为80%和22.7%,两者间比较差异有统计学意义(P<0.05),DCC的表达与宫颈癌的临床分期呈正相关(P<0.01);C-erbB-2在慢性宫颈炎、宫颈癌组织中的阳性表达率分别为30.0%和86.4%,两者比较差异有统计学意义(P<0.05),C-erbB-2的表达与宫颈癌的临床分期呈正相关(P<0.05);DCC与C-erbB-2在宫颈癌组织中存在协同作用。结论:DCC在宫颈癌的生长、浸润和转移过程中发挥一定作用,其检测可为宫颈癌的预后判断提供必要的理论依据;C-erbB-2作为影响细胞凋亡因子,在宫颈癌的发生、发展过程中起一定作用;DCC与C-erbB-2在宫颈癌组织中的表达有相关性。     

DCC is required for the tangential migration of noradrenergic neurons in locus coeruleus of mouse brain

The tangential migration from the dorsal rhombomere (r) 1 to the dorsolateral pontine tegmentum is a crucial event in the development of locus coeruleus (LC), but the molecular mechanisms underlying the migration are not well understood. We show that the Netrin receptor DCC is expressed in LC neurons and is required for their tangential migration. In DCC^−/− embryos, fate determination of LC neurons appeared normal but tangential migration failed to initiate properly. Although many LC neurons eventually reached the dorsolateral pontine tegmentum in DCC^−/− embryos at late embryonic stages, a substantial number of LC neurons were abnormally distributed in the rostral pons and cerebellum. In DCC^kanga mice that lack the intracellular P3 domain of DCC, these defects were not observed. In addition, although Unc5h3, another Netrin receptor, was expressed in the dorsal r1, Unc5h3^−/− mice exhibited the normal LC morphology and gene expression profiles in the LC compared with wild-type mice. Thus, our findings demonstrate that DCC is a key regulator of tangential migration of LC neurons during the embryonic development.     

Colorectal cancer in a population with endemic Schistosoma mansoni: is this an at-risk population?

Purpose Chronic infection with schistosomiasis has been clearly associated with the development of bladder cancer, and infestation is associated with a high incidence of colorectal cancer in endemic populations. Despite this association, the potential role of alterations in tumor suppressor genes colorectal cancers has never been evaluated in an endemically infected population. The aim of this paper was to compare histopathologic and genetic changes in schistosomal colitis-associated colorectal cancer (SCC) with colorectal cancer in a group of patients from the same population not affected by the disease (NDCC). Materials and methods Sixty patients were included in this study: SCC—40, NDCC—20. Data collected included age, sex, clinical presentation, presence of synchronous tumors, histopathology, and clinical stage. p53, DCC (deleted in colorectal cancer gene), and mismatch repair genes (MLH1 and MSH2) were studied using immunohistochemical staining. Results Patients with SCC were significantly younger than the NDCC group (34.52±11.22 years vs 50.73±12.75 years, p=0.02). Mucinous adenocarcinoma occurred significantly more frequently in SCC (35 vs 10%, p=0.02). SCC tumors were more frequently stage III or IV, and significantly more synchronous tumors were present in the affected group (SCC—8/40 vs NDCC—1/20, p=0.05). p53 staining was far more frequent in SCC (SCC—32/40 vs NDCC—8/20, p=0.006). DCC expression was similar in two groups. There were only four cases, three in SCC and one in NDCC, that showed microsatellite instability. Conclusion The data suggest that schistosomal colitis is more commonly associated with earlier onset of multicentric colorectal cancer, high percentage of mucinous adenocarcinoma, and presents at an advanced stage. The identification of a higher incidence of altered p53 expression in the SCC group raises the possibility of an association between schistosomiasis and alterations in p53 activation as an inciting event in colorectal cancer development.     

Liporetro-D-peptides - a novel class of highly selective thrombin inhibitors

Introduction

Plasma serine protease thrombin plays a key role in coagulation, haemostasis and thromboembolic diseases. Direct thrombin inhibitors could be beneficial for future anticoagulant therapy. We have synthesized and studied liporetro-D-peptides - efficient thrombin inhibitors resistant to enzymatic degradation.

Materials and Methods

Compounds X-D-Arg-D-Phe-OMe, where X = residue of lauric or myristic acid or 9-fluorenylmethoxycarbonyl, have been synthesized by conventional peptide synthesis in solution and their comparative inhibitory analysis in relation to thrombin, factor X, plasmin and trypsin has been conducted.

Results

Modification of the synthetic liporetro-D-peptides with the myristic acid residue was the most successful one. This modification has dramatically increased the inhibition efficacy (Ki = 0,17 μM) and selectivity toward the chosen target enzyme, thrombin, in comparison to factor X, plasmin and trypsin (more than 600, 900, and 5000-fold, respectively).

Conclusions

Our findings establish an important role of the fatty moiety in the structure of peptide inhibitors with regards to their potency and selectivity toward thrombin.     

Juvenile exposure to methylphenidate reduces cocaine reward and alters netrin-1 receptor expression in adulthood

The guidance cue netrin-1 acting on mesocorticolimbic dopamine (DA) neurons through its receptor DCC (deleted in colorectal cancer) has been implicated in the neuronal plasticity induced by psychostimulant drugs. We examined in C57/BL6 mice the effects of repeated juvenile methylphenidate (MPH) exposure on cocaine-reward sensitivity in adulthood and determined whether early MPH treatment alters adult expression of DCC in mesocorticolimbic DA regions. By using place conditioning, we show that adult mice exposed to MPH during the juvenile period are less sensitive to cocaine-reward compared to saline-controls. Furthermore, by means of immunoblotting, we demonstrate that early MPH treatment attenuates adult DCC expression in the ventral tegmental area (VTA) selectively. These results support previous evidence that developmental MPH treatment diminishes cocaine-reward in adulthood and are the first to suggest that DCC in the VTA may participate in this enduring effect.     

胃癌组织DCC基因表达的研究

应用逆转录多聚酶链反应（ＲＴ－ＰＣＲ）技术对２６例胃癌组织ＤＣＣ基因ｍＲＮＡ的表达进行分析。２６例胃癌中发现表达缺失８例，占３０．７％。在不同类型胃癌中，肠型胃癌表达缺失占４４．４％（４／９），弥漫型为２３．５％（４／１７）。ＤＣＣ基因表达改变与临床病理因素无显著相关（Ｐ＞０．０５）。以上结果提示ＤＣＣ基因表达缺失在胃癌的发生发展中可能起一定作用     

原发性肝癌结肠癌缺失基因杂合缺失研究

目的：了解结肠癌缺失基因（ＤＣＣ基因）在原发性肝癌发生发展中作用，方法：采用多聚酶链延伸反应－限制性片生长度多态性分析（ＰＣＲ－ＲＦＬＰ）方法对３０例外科手术切除原肝癌标本ＤＣＣ基因杂合缺失（ＬＯＨ）进行分析，结果：２８例信息个体中检出ＬＯＨ７例，占２５．０％，ＤＣＣ基因ＬＯＨ与临床病理参数和ＨＢＶ感染无显著相关，结论：ＤＣＣ基因ＬＯＨ可能参与了原发肝癌的发生发展。