Tumor-specific lytic path “hyperploid progression mediated death”: Resolving side effects through targeting retinoblastoma or p53 mutant

A major advance was made to reduce the side effects of cancer therapy via the elucidation of the tumor-specific lytic path “hyperploid progression-mediated death” targeting retinoblastoma (Rb) or p53-mutants defective in G1 DNA damage checkpoint. The genetic basis of human cancers was uncovered through the cloning of the tumor suppressor Rb gene. It encodes a nuclear DNA-binding protein whose self-interaction is regulated by cyclin-dependent kinases. A 3D-structure of Rb dimer is shown, confirming its multimeric status. Rb assumes a central role in cell cycle regulation and the “Rb pathway” is universally inactivated in human cancers. Hyperploidy refers to a state in which cells contain one or more extra chromosomes. Hyperploid progression occurs due to continued cell-cycling without cytokinesis in G1 checkpoint-defective cancer cells. The evidence for the triggering of hyperploid progression-mediated death in RB-mutant human retinoblastoma cells is shown. Hence, the very genetic mutation that predisposes to cancer can be exploited to induce lethality. The discovery helped to establish the principle of targeted cytotoxic cancer therapy at the mechanistic level. By triggering the lytic path, targeted therapy with tumor specificity at the genetic level can be developed. It sets the stage for systematically eliminating side effects for cytotoxic cancer therapy.     

死亡结构域相关蛋白及其在宫颈病变中的研究进展

宫颈癌对妇女健康构成严重威胁,人乳头瘤病毒感染与宫颈病变及宫颈癌的发生密切相关。关于宫颈癌发生发展的机制仍在研究中。近年研究发现一种多功能核蛋白,即死亡结构域相关蛋白(death domain associated protein,Daxx),其与细胞内蛋白或病毒蛋白相互作用,参与调节细胞凋亡、转录调控、抗病毒等细胞活动,在不同途径中发挥不同的生理或病理作用。通过对Daxx功能及其作用机制的研究有助于进一步阐明宫颈癌发生发展的机制,有助于发现新的预防和治疗方法。综述Daxx的一般特性和研究现况及其在宫颈病变的研究进展。     

炎症性肠病患儿血清Th17相关细胞因子表达及其意义

目的　探讨儿童IBD患者血清中Th17相关细胞因子的表达水平及其临床意义。方法　收集2017年4月至2019年5月在西安交通大学附属儿童医院消化科住院治疗的儿童IBD患者40例，以同期21例非炎症性疾病儿童作为对照组。采集受检者血清标本，通过酶联免疫吸附试验检测白细胞介素-17A（IL-17A）、 IL-17F、 IL-21、 IL-22、 IL-25的表达水平。结果　IL-17A、 IL-17F、 IL-21和IL-22在溃疡性结肠炎（UC）及克罗恩病（CD）患儿血清中表达明显升高，IL-25明显降低（P＜0.05）；IL-17A、 IL-17F及IL-21血清水平与UC患儿疾病活动度呈正相关（P＜0.05）；IL-21在UC患儿血清中的表达与IL-17A和IL-17F的表达呈正相关（P＜0.05）。结论　Th17相关细胞因子在IBD患儿血清中表达失调，为进一步研究Th17细胞在儿童IBD中的作用提供了依据；IL-17A、 IL-17F、 IL-21血清水平与UC患儿疾病活动度呈正相关，表明其可能是Th17细胞触发儿童UC的重要促炎细胞因子。     

Novel Compounds Identified by Structure-Based Prion Disease Drug Discovery Using In Silico Screening Delay the Progression of an Illness in Prion-Infected Mice

The accumulation of abnormal prion protein (PrP^Sc) produced by the structure conversion of PrP (PrP^C) in the brain induces prion disease. Although the conversion process of the protein is still not fully elucidated, it has been known that the intramolecular chemical bridging in the most fragile pocket of PrP, known as the “hot spot,” stabilizes the structure of PrP^C and inhibits the conversion process. Using our original structure-based drug discovery algorithm, we identified the low molecular weight compounds that predicted binding to the hot spot. NPR-130 and NPR-162 strongly bound to recombinant PrP in vitro, and fragment molecular orbital (FMO) analysis indicated that the high affinity of those candidates to the PrP is largely dependent on nonpolar interactions, such as van der Waals interactions. Those NPRs showed not only significant reduction of the PrP^Sc levels but also remarkable decrease of the number of aggresomes in persistently prion-infected cells. Intriguingly, treatment with those candidate compounds significantly prolonged the survival period of prion-infected mice and suppressed prion disease-specific pathological damage, such as vacuole degeneration, PrP^Sc accumulation, microgliosis, and astrogliosis in the brain, suggesting their possible clinical use. Our results indicate that in silico drug discovery using NUDE/DEGIMA may be widely useful to identify candidate compounds that effectively stabilize the protein.Electronic supplementary materialThe online version of this article (10.1007/s13311-020-00903-9) contains supplementary material, which is available to authorized users.     

miR-513a-5p慢病毒载体的构建及其对人骨肉瘤细胞放疗敏感性的影响

目的:构建miR-513a-5p慢病毒过表达载体，转染人骨肉瘤细胞株，观察miR-513a-5p对人骨肉瘤细胞放疗敏感性的影响。方法:PCR法扩增人miR-513a-5p基因，克隆入pLentis-CMV-GFP-MCS-PGK-PURO载体获得重组质粒pLentis-miR513a，双酶切鉴定并测序后将正确的重组质粒和对照质粒转染293FT细胞制备慢病毒，分别转染骨肉瘤HOS和U2OS细胞，qRT-PCR法及荧光显微镜鉴定转染结果。克隆形成实验、MTT法检测miR-513a-5p高表达HOS和U2OS细胞在X射线照射下细胞存活情况。结果:双酶切及测序结果确定成功构建miR-513a-5p慢病毒载体pLentis-miR513a。qRT-PCR结果提示，转染骨肉瘤细胞株后miR-513a-5p表达显著升高。克隆形成实验结果显示miR-513a-5p高表达后骨肉瘤细胞在X射线照射下细胞增殖减慢。MTT结果提示miR-513a-5p高表达骨肉瘤细胞经X射线照射后细胞存活减少。结论:成功构建了miR-513a-5p慢病毒载体，建立了高效稳定表达miR-513a-5p的骨肉瘤细胞株，高表达miR-513a-5p能显著增加X射线照射后骨肉瘤细胞的放疗敏感性。