靶向CD59的siRNA抑制人卵巢癌细胞A2780裸鼠移植瘤的实验研究

目的:通过体内动物实验研究CD59-siRNA对卵巢癌移植瘤CD59的沉默效应及其抑瘤作用,探讨CD59在肿瘤免疫逃逸中的作用.方法:采用脂质体转染法将CD59干扰质粒(T组)和空质粒(V组)转染A2780细胞,获得稳定表达细胞株,将前两组A2780细胞和未转染(C组)的A2780细胞分别接种于裸鼠皮下建立肿瘤模型,通过绘制肿瘤生长曲线、RT-PCR和Western Blot 研究其抑瘤效应及对CD59的沉默效应.结果:肿瘤生长曲线显示,与对照组相比,CD59干扰质粒转染组肿瘤生长明显受抑制(P<0.05). RT-PCR和Western Blot结果表明,干扰组的CD59mRNA及CD59蛋白与对照组相比显著降低(P<0.05).结论:动物实验表明,特异性沉默CD59基因的siRNA表达载体可以明显抑制CD59的表达及卵巢癌在体内的生长,进一步说明了CD59在肿瘤免疫逃逸中的作用.     

肿瘤干细胞标记物CD_(133)与miR-429在大肠癌组织中的表达及其相关性研究

目的:检测CD133不同亚群大肠癌细胞HT-29的miR-429表达情况,探讨miR-429及CD133的表达与肿瘤的发生发展之间的关系。方法:采用荧光活化细胞分选法(FACS)分选出CD133不同亚群细胞,实时荧光定量PCR分别检测两组细胞miR-429的表达,合成miR-429寡核苷酸和阴性对照miRNA并分别转染CD133+和CD133-两个亚群细胞。再将细胞种植于非肥胖糖尿病/严重联合免疫缺陷(NOD/SCID)小鼠体内构建移植瘤模型,不同时间测量肿瘤体积和重量,RT-PCR及蛋白质印迹检测CD133+和CD133-两组肿瘤CD133mRNA和蛋白质表达。结果:血清检出CD133+细胞为67.9%,miR-429的表达量是CD133+细胞的(1.83±0.91)倍(P0.05),CD133+比例与miR-429表达呈负相关(r=0.591,P0.05);miR-429+/CD133+组的移植瘤体积及重量与对照组比较有统计学差异(P0.05),且miR-429+/CD133+组成瘤时间较对照组晚约2周,但miR-429+/CD133+组的移植瘤CD133表达量低,与阴性对照组比较无明显差异(P0.05)。结论:miR-429可能作为CD133的负性调控因子,具有抑制肿瘤生长的作用,但miR-429与CD133在肿瘤发生、发展过程中的作用机制有待进一步研究阐明。     

小檗碱对CT26皮下移植瘤组织中肿瘤相关巨噬细胞的影响

目的观察小檗碱的抑瘤作用及其对肿瘤组织内肿瘤相关巨噬细胞数量的影响。方法 BABL/c小鼠40只随机分2组,全部皮下移植结肠癌细胞(CT26细胞系),次日进行药物干预。治疗组小鼠腹腔注射小檗碱,100mmol/L,200μl/d,14d;对照组腹腔注射等量生理盐水。肿瘤细胞接种7d后连续动态测定肿瘤体积,接种15d处死全部动物,取肿瘤组织、免疫组织化学显色检测肿瘤组织中M2型巨噬细胞标志物CD206及CD68的表达。结果小鼠皮下移植CT26后,小檗碱治疗组小鼠皮下移植瘤生长缓慢。与对照组比较,肿瘤体积及瘤重均显著减少(P<0.05);皮下移植15d肿瘤组织中可见大量CD206及CD68阳性细胞;肿瘤组织中CD206及CD68阳性细胞数量显著减少(P<0.05 orP<0.01)。结论小檗碱可能通过抑制肿瘤相关巨噬细胞的形成而发挥抗肿瘤作用。     

EB病毒诱发人B细胞淋巴瘤的分子病理特性

EB病毒 (EBV ,Epstein Barrvirus)与人类多种肿瘤有关 ,尤其是与鼻咽癌和淋巴瘤的关系密切。为此研究了EB病毒在huPBL SCID嵌合体小鼠体内诱发人B细胞淋巴瘤的分子特性及肿瘤发生机制。从健康成人外周血分离出淋巴细胞 ,将之移植到SCID小鼠腹腔内 ,实验感染EBV ,观察肿瘤的形成 ;采用单向免疫扩散法连续监测小鼠血清中人IgG的含量。分别用PCR方法检测肿瘤组织中是否存在人Alu序列 ,原位杂交检测肿瘤组织中EB病毒小RNA分子EBER 1;免疫组织化学方法检测人白细胞分化抗原 (CD4 5、CD2 0、CD4 5RO、CD3) ,病毒基因(LMP1、EBNA2、BZLF1)的表达 ,以及细胞瘤基因蛋白 (p5 3、C myc、Bcl 2、Bax)在诱发肿瘤中的表达情况。结果发现 ,实验中 34只感染EBV的huPBL SCID小鼠有 2 4只诱发出肿瘤 ,根据病理形态学特征、Alu PCR和免疫标志均证实诱发瘤是人源性B淋巴细胞肿瘤。原位分子杂交显示肿瘤细胞核内存在EBER 1,少数瘤细胞表达EB病毒BZLF1蛋白阳性 ,部分瘤细胞表达LMP1和EBNA2蛋白阳性。连续监测 12只huPBL SCID小鼠血清中人IgG含量 ,发现IgG水平随诱瘤时间延长和肿瘤生长有逐渐增高趋势。免疫组化显示诱发的 2 4例淋巴瘤组织p5 3、C myc、Bcl 2和Bax蛋白表达阳性率分别为 83.33%、10 0 %、95 .83%、91.6 7%。结果     

敲低肿瘤细胞来源的颗粒体蛋白前体抑制C57BL/6J小鼠黑色素移植瘤的生长北大核心CSCD

颗粒体蛋白前体(progranulin,PGRN)在多种肿瘤中过表达。但PGRN在黑色素瘤发生发展中的作用尚无报道。为探究PGRN在黑色素肿瘤中的作用,本研究采用CRISPR-Cas9基因编辑技术建立了稳定敲低PGRN的小鼠黑色素瘤B16细胞株B16-PGRNlow。MTS法和Brd U掺入结合流式细胞(计量)术分析证明,敲低PGRN不影响B16细胞的细胞周期和增殖。将B16-ctrl(对照)和B16-PGRNlow细胞分别皮下接种野生型(WT)和PGRN敲除(KO)的C57BL/6J小鼠,比较观察黑色素移植瘤体积大小。移植瘤形成20 d后,与B16-ctrl细胞接种的移植瘤比较,无论在WT还是在KO荷瘤小鼠,B16-PGRNlow形成的移植瘤体积明显减小(WT鼠:P<0.05;KO鼠:P<0.01)。然而,比较B16-PGRNlow或B16-ctrl在WT鼠与KO鼠形成的移植瘤体积大小,并无显著差异,提示B16肿瘤细胞PGRN而非宿主PGRN影响移植瘤的生长。流式细胞术分析显示,在荷B16-PGRNlow移植瘤的WT型小鼠脾和淋巴结中,CD4+、CD8+T细胞数(百分比)比荷B16-ctrl移植瘤的WT鼠脾和淋巴结的CD4+、CD8+T细胞数明显增多(P<0.05,P<0.01),而在KO鼠却未见明显差异。上述结果证明,敲低肿瘤细胞PGRN可抑制黑色素移植瘤的生长。上述结果还提示,抑制PGRN在黑色瘤的表达可引起脾和淋巴结CD4+和CD8+T细胞增加,提高宿主的细胞免疫能力。其机制尚待进一步研究。本文的发现为PGRN作为黑色素瘤治疗的潜在靶点提供了新证据。     

生物信息大分子功能的研究——酵母甘露聚糖对鼠Sarcoma-180瘤生长的抑制效应

酵母甘露聚糖（Mannan,简称Man）是能参与生物信息流影响生物体、特别是在糖基化方面起着重要调控作用的生物信息大分子.它是否能在抑制生物机体中肿瘤生长方面具有重要作用？研究结果表明：酵母甘露聚糖既能使患S-180瘤鼠的体质增强的同时又有抑制其体内所患S-180瘤生长的功效.Man抑制患鼠机体内的S-180瘤生长的功效（抑瘤率）随用量的增加而提高,当Man用量达360 mg（40 mg/Kg/d·9d）时,其抑瘤率达98.4％的最高水平,此时鼠体重增加1.66倍.Man的抑瘤功效有最佳适用量并存在性别敏感性,通常是雄性鼠的抑瘤率高于雌性鼠.Man抑制鼠S-180肿瘤生长的作用优于市售5-氟尿嘧啶的作用.     

MiRNA-221/222 对肝癌的影响研究进展

MicroRNAs(mi RNAs)在人类肿瘤致瘤生长机制的作用在肝细胞肝癌(hepatocellular carcinoma,HCC)中已经通过基因增殖和功能性研究所证实。肝癌中异常表达的miRNAs与其他类型的肿瘤有密切关系,其中较为独特的是上调的miR-221/222。MiR-221/222是高度同源基因,在HCC中明显上调,被认为是致瘤基因。本文对miR-221/222的分子及生物机制进行综述,并对其作为新的HCC诊断及治疗工具的可能性做出探讨。     

PVAX-MAGE-1基因疫苗延缓小鼠肝癌细胞H22腹水瘤和实体瘤的生长

为观察重组基因疫苗PVAX-MAGE-1的抑瘤效应,构建黑色素瘤抗原-1(melanoma antigen-1,MAGE-1)真核基因表达载体--PVAX-MAGE-1.以重组质粒免疫C57BL/6小鼠后,ELISA法检测表明,与对照鼠(PVAX-1和生理盐水注射小鼠)比较,免疫小鼠脾淋巴细胞上清液中的细胞因子IL-2和IFN-γ明显升高(P0.05);淋巴细胞-肿瘤细胞混合培养证明,免疫小鼠外周血CD8+T细胞对靶细胞的特异性杀伤作用明显增强(P0.05).体内实验证明,PVAX-MAGE-1免疫C57BL/6小鼠,可显著延缓移植性H22腹水瘤及实体瘤在小鼠体内的生长.实验结果提示,重组基因疫苗PVAX-MAGE-1有明显的延缓肿瘤生长的作用,其抑瘤作用与提高T淋巴细胞IL和IFN表达,增强对肿瘤杀伤作用直接相关.     

人喉癌细胞系Hep-2 中CD133 阳性肿瘤干细胞的分离及意义

目的:研究喉癌细胞系Hep-2中CD133的表达;比较CD133~+细胞、未分选细胞、CD133~-细胞的体外增殖、克隆形成能力及其在裸鼠体内的成瘤能力;探讨喉癌肝细胞对化疗药物顺铂(cisplatin,DDP)的抵抗作用。方法:采用流式细胞仪检测CD133在Hep-2细胞系中的表达;免疫磁珠分选技术纯化CD133阳性肿瘤细胞;使用四甲基偶氮唑蓝(MTT)法和平板克隆形成实验检测分选所得各细胞亚群细胞以及未分选细胞的体外增殖能力和克隆形成能力;将CD133阳性肿瘤细胞和CD133阴性肿瘤细胞以一定的数量级注入重症联合免疫缺陷小鼠腹部皮下,比较其成瘤差异性;此外,使用DDP干预分选所得各细胞亚群细胞,检测比较CD133阳性肿瘤细胞和CD133阴性肿瘤细胞的体外增殖能力与体内成瘤能力。结果:流式细胞仪示CD133在Hep-2细胞系中呈微量恒定表达,表达概率为40.12±1.32%;CD133阳性肿瘤细胞的体外增殖能力显著强于CD133阴性肿瘤细胞的增殖能力(P0.05),且其克隆形成能力也强于CD133阴性肿瘤细胞;体内成瘤实验结果显示CD133阳性肿瘤细胞较CD133阴性细胞、未分选细胞在重症联合免疫缺陷小鼠体内具有更强的成瘤性(P0.05);在DDP的干预下,相对于CD133阴性肿瘤细胞,CD133阳性肿瘤细胞表现出更强的抵抗力。结论:喉癌Hep-2细胞系中,CD133阳性癌细胞具有强的体外增殖能力、体内成瘤能力且对化疗药物具有较强的抵抗性,可作为喉癌肿瘤干细胞的标志之一。     

CD151在垂体腺瘤中的表达及意义

目的:探讨CD151在垂体腺瘤中的表达及意义。方法:收集36例垂体腺瘤标本,5例正常垂体组织,通过Real time-PCR、Western blot及免疫组化方法,从mRNA和蛋白水平检测CD151在36例垂体腺瘤、5例正常垂体组织的表达。结果:Real time-PCR及Western blot、免疫组化发现CD151在垂体肿瘤组织中表达显著高于正常垂体组织(P0.01),在非侵袭性腺瘤和侵袭性腺瘤中的蛋白及mRNA表达量两者之间有显著差异(P0.01)。结论:CD151的表达与肿瘤大小及侵袭程度相关,表明CD151的表达与肿瘤的发生、发展密切相关,检测CD151有可能预测垂体腺瘤预后的重要指标。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.