Genotypic characteristics of resistant tumors to pre-operative ionizing radiation in rectal cancer

Due to a wide range of clinical response in patients un-dergoing neo-adjuvant chemoradiation for rectal cancer it is essential to understand molecular factors that lead to the broad response observed in patients receiving the same form of treatment.Despite extensive research in this field,the exact mechanisms still remain elusive.Data raging from DNA-repair to specific molecules lead-ing to cell survival as well as resistance to apoptosis have been investigated.Individually,or in combination,there is no single pathway that has become clinically applicable to date.In the following review,we describe the current status of various pathways that might lead to resistance to the therapeutic applications of ionizing radiation in rectal cancer.

Mechanism of exogenous nucleic acids and their precursors improving the repair of intestinal epithelium after 7-irradiation in mice

AIM To clone expressed genes associated withrepair of irradiation-damaged mice intestinalgland cells treated by small intestinal RNA,andto explore the molecular mechanism ofexogenous nucleic acids improving repair ofintestinal crypt.METHODS The animal mode of test group andcontrol group was established,forty-five micebeing irradiated by γ ray were treated with smallintestinal RNA as test group,forty mice beingirradiated by γ ray were treated withphysiological saline as control group,five micewithout irradiation were used as normal control,their jejunal specimens were collectedrespectively at 6h,12h,24h,4d and 8d afterirradiation.Then by using LD-PCR based onsubtractive hybridization,these gene fragmentsdifferentially expressed between test group andcontrol group were obtained,and then werecloned into T vectors as well as beingsequenced.Obtained sequences were screenedagainst.GeneBank,if being new sequences,they were submitted to GeneBank.RESULTS Ninety clones were associated withrepair of irradiation-damaged intestinal glandcells treated by intestinal RNA.These clonesfrom test group of 6h,12h,24h,4d and 8dwere respectively 18,22,25,13,12.By screening against GeneBank,18 of which werenew sequences,the others were dramaticallysimilar to the known sequences,mainly similarto hsp,Nmi,Dutt1,alkaline phosphatase,homeobox,anti-CEA ScFv antibody,arginine/serine kinase and BMP-4,repA.Eighteen genefragments were new sequences,their acceptnumbers in GeneBank were respectivelyAF240164-AF240181.CONCLUSION Ninety clones were obtained tobe associated with repair of irradiation-damagedmice intestinal gland cells treated by smallintestinal RNA,which may be related toabnormal expression of genes and matchedproteins of hsp,Nmi,Duttl,Na,K-ATPase,alkalineph-osphatase,glkA,single strandedreplicative centromeric gene as well as 18 newsequences.

Late Effects of Radiation on Skeletal Muscle: An Open Field of Research

This paper presents an overview of the state of the art about the late effects of ionizing radiation on skeletal muscle, helping new research and showing unexplored areas. For this, it was evaluated the interest reported by the scientific literature regarding the late effects in skeletal muscle resulting from exposure to ionizing radiation. Original and experimental papers mainly containing the key expressions “ionizing radiation” and “effects on skeletal muscle” were searched in computerized databases, and published in any language. Only 33 papers matched the search criteria. Analyzing the investigated radioinduced biological effects in those contributions, four topics were identified as being of major interest: 1) alterations in cellular metabolism and protein degradation;2) repercussions on satellite cells;3) formation of fibrosis and muscle atrophy;4) tissue regeneration. It was verified that no study evaluated possible late effects related to either morphology or properties of skeletal muscles after an exposure to ionizing radiation. Several aspects do not make possible a successful replication;all experiments of eligible group of articles are discussed, such as, lack of raw data, use of no sound methodology and inappropriate statistical technique. Briefly, the subject of this review is an open field of research.

Potential for a pluripotent adult stem cell treatment for acute radiation sickness

Accidental radiation exposure and the threat of deliberate radiation exposure have been in the news and are a public health concern. Experience with acute radiation sickness has been gathered from atomic blast survivors of Hiroshima and Nagasaki and from civilian nuclear accidents as well as experience gained during the development of radiation therapy for cancer. This paper reviews the medical treatment reports relevant to acute radiation sickness among the survivors of atomic weapons at Hiroshima and Nagasaki, among the victims of Chernobyl, and the two cases described so far from the Fukushima Dai-Ichi disaster. The data supporting the use of hematopoietic stem cell transplantation and the new efforts to expand stem cell populations ex vivo for infusion to treat bone marrow failure are reviewed. Hematopoietic stem cells derived from bone marrow or blood have a broad ability to repair and replace radiation induced damaged blood and immune cell production and may promote blood vessel formation and tissue repair. Additionally, a constituent of bone marrow-derived, adult pluripotent stem cells, very small embryonic like stem cells, are highly resistant to ioniz-ing radiation and appear capable of regenerating radiation damaged tissue including skin, gut and lung.

Ionizable drug delivery systems for efficient and selective gene therapy

Gene therapy has shown great potential to treat various diseases by repairing the abnormal gene function.However,a great challenge in bringing the nucleic acid formulations to the market is the safe and effective delivery to the specific tissues and cells.To be excited,the development of ionizable drug delivery systems(IDDSs)has promoted a great breakthrough as evidenced by the approval of the BNT162b2 vaccine for prevention of coronavirus disease 2019(COVID-19)in 2021.Compared with conventional cationic gene vectors,IDDSs can decrease the toxicity of carriers to cell membranes,and increase cellular uptake and endosomal escape of nucleic acids by their unique pH-responsive structures.Despite the progress,there remain necessary requirements for designing more efficient IDDSs for precise gene therapy.Herein,we systematically classify the IDDSs and summarize the characteristics and advantages of IDDSs in order to explore the underlying design mechanisms.The delivery mechanisms and therapeutic applications of IDDSs are comprehensively reviewed for the delivery of plasmid DNA(pDNA)and four kinds of RNA.In particular,organ selecting considerations and high-throughput screening are highlighted to explore efficiently multifunctional ionizable nanomaterials with superior gene delivery capacity.We anticipate providing references for researchers to rationally design more efficient and accurate targeted gene delivery systems in the future,and indicate ideas for developing next generation gene vectors.

Gene Expression Profiles Predict Sensitivity of Prostate Cancer to Radiotherapy

Ionizing radiation (IR) is the most common treatment used to control localized primary prostate cancer (PC). However, for a significant number of patients, radiotherapy fails to adequately control the tumor. Thus, a main clinical problem today is the lack of a specific marker that may be used to predict the treatment outcome and to identify prostate cancer patients who are unlikely to respond to radiation therapy. In this study, we used human PC xenografts with predetermined radioresistant/sensitive phenotypes, and gene expression microarrays, correlated their specific transcripttional profiles with response to radiation. Employing unsupervised two-way hierarchical clustering, we identified four gene clusters displaying different expression patterns. Two clusters showed higher expression levels in the resistant xenografts and the other two clusters showed higher expression levels in the sensitive xenografts. Expression levels of 113 genes differed by at least 3 fold between sensitive and resistant xenografts. These genes represent members of several cellular pathways, some of which are known to be associated with response to radiation. All or several of these genes could serve as predictive tools to determine at biopsy the expected response of a particular tumor to radiotherapy. Indeed, the profiles we identified enabled us to predict the degree of radiosensitivity of a panel of established PC cell lines. Importantly, irradiation of the PC xenografts did not induce any significant changes in gene expression, regardless of their susceptibility phenotype. These data strongly support the first of two models: a: a random effect of irradiation on a homogeneous population of cells, rather than b: of a tumor comprised of a mixture of radioresistant and radiosensitive cell subpopulations. Our findings imply that each of the radio-phenotypes represents different intrinsic characteristics that affect the ability of a tumor to survive radiotherapy.

复方斑蝥胶囊联合旋转容积调强技术对头颈部放疗生存期及血清XRCC1、XRCC3mRNA水平的影响

目的探究复方斑蝥胶囊联合旋转容积调强技术对头颈部放疗患者生存期及血清X线修复交错互补基因1(X-ray Repair Cross Complementing 1,XRCC1)、X线修复交错互补基因3(X-ray Repair Cross Complementing 3,XRCC3)信使核糖核酸(Messenger RNA,mRNA)水平的影响。方法选取2019年6月—2021年7月医院收治的头颈部肿瘤患者97例作为研究对象,根据治疗方法不同进行分组,对照组(48例)采用旋转容积调强技术结合放疗治疗,联合组(49例)在对照组基础上加用复方斑蝥胶囊治疗。观察比较临床疗效、中医证候积分、血清XRCC1及XRCC3mRNA水平、生存期、不良反应。结果联合组客观缓解率高于对照组(P<0.05),但疾病控制率与对照组比较差异无统计学意义(P>0.05)。联合组自汗、恶心呕吐、神疲乏力、食欲差、失眠、头晕眼花等得分低于对照组(P<0.05)。联合组血清XRCC1、XRCC3水平及外周血XRCC1、XRCC3 mRNA表达均低于对照组(P<0.05)。联合组无进展生存期和总生存期均高于对照组(P<0.05)。联合组不良反应发生率(34.69%,17/49)低于对照组不良反应发生率(72.92%,35/48)(P<0.05)。结论复方斑蝥胶囊联合旋转容积调强技术能改善头颈部放疗患者肿瘤客观缓解率,缓解临床症状,降低血清XRCC1、XRCC3mRNA水平,减少不良反应。

PTW Detector7293种剂量验证方法在调强放射治疗中的对比研究

目的 :对比PTW Detector729 3种验证方法在调强放射治疗(intensity modulated radiation therapy,IMRT)剂量验证中的差异。方法:回顾性选取2022年1—12月于某院完成放射治疗的鼻咽癌、肺癌、乳腺癌、宫颈癌和全脑放射治疗患者共50例,使用PTW Detector729二维电离室矩阵配合PTW RW3固体水与PTW Ocavius 4D旋转模体对50例患者的IMRT计划分别进行归零机架角2D剂量验证、实际机架角2D剂量验证和实际机架角3D剂量验证。将剂量评估阈值设为10%,统计3种验证方法在3%/1 mm、2%/2 mm、3%/2 mm和3%/3 mm 4种评估标准下的γ通过率。采用SPSS 22.0统计学软件进行数据分析。结果:在10%剂量评估阈值标准下,归零机架角2D剂量验证的γ通过率最高,差异有统计学意义(P<0.05);实际机架角2D剂量验证的γ通过率高于实际机架角3D剂量验证,差异有统计学意义(P<0.05)。3种验证方法的γ通过率在3%/1 mm、2%/2 mm、3%/2 mm和3%/3 mm 4种标准下逐渐升高,且在3%/2 mm标准下均超过90%,结果满足临床放射治疗要求。结论:3种验证方法的验证结果均能达到IMRT剂量验证实践指南要求,根据IMRT开展情况选择合适的验证方法,对确保治疗方案安全、有效实施具有重要意义。

Current status of tumor radiogenic therapy

Although tumor gene therapy falls behind its clinical use, the combination of irradiation and gene therapy is full ofpromise in cancer therapy based on traditional radiotherapy, chemotherapy and surgery. We have termed it as radiogenic therapy. This review focuses on the following aspects of radiogenic therapy in recent years: improvement of gene transfer efficiency by irradiation, radiotherapy combined with cytokine gene delivery or enhancement of the immunity of tumor cells by transgene, direct stimulation by radiation toproduce cytotoxic agents, increase of tumor cell radiosensitivity in gene therapy by controlling the radiosensitivity genes and adjusting the fraction dose and interval of radiation so as to achieve the optimum antitumor effect while reducing the normal tissue damage, radioprotective gene therapy enhancing radiation tumor killing effect while protecting the normal tissue and organs with transgene using transfer vectors.

Functional promoter rs189037 variant of ATM is associated with decrease in lung diffusing capacity after irradiation for nonesmall-cell lung cancer

Objective: Single-nucleotide polymorphisms (SNPs) in the ataxia telangiectasiaemutated gene ATM have been linked with pneumonitis after radiotherapy for lung cancer but have not been evaluated in terms of pulmonary function impairment. Here we investigated potential associations between SNPs in ATM and changes in diffusing capacity of the lung for carbon monoxide (DLCO) in patients with nonesmall-cell lung cancer (NSCLC) after radiotherapy. Methods: From November 1998 through June 2009, 448 consecutive patients with inoperable primary NSCLC underwent definitive (≥60 Gy) radiotherapy, with or without chemotherapy. After excluding patients with a history of thoracic surgery, ra-diation, or lung cancer; without DNA samples available for analysis; or without pulmonary function testing within the 12 months before and the 12 months after radiotherapy, 100 patients were identified who are the subjects of this study. We genotyped two SNPs of ATM previously found to be associated with radiation-induced pneumonitis (rs189037 and rs228590) and evaluated potential correlations between these SNPs and impairment (decreases) in DLCO by using logistic regression analysis. Results: Univariate and multivariate analyses showed that the AA genotype of ATM rs189037 was associated with decreased DLCO after definitive radiotherapy than the GG/AG genotypes (univariate coefficient, -0.122; 95％ confidence interval (CI),-0.236 to -0.008; P = 0.037; and multivariate coefficient, -0.102; 95％ CI, -0.198 to -0.005; P = 0.038)No such correlations were found for rs228590 (univariate coefficient, -0.096; 95％ CI, -0.208 to 0.017; P = 0.096). Conclusions: The AA genotype of ATM rs189037 was associated with higher risk of lung injury than were the GG/AG genotypes in patients with NSCLC treated with radiotherapy. This finding should be validated prospectively with other patient populations.

Changes in human pluripotent stem cell gene expression after genotoxic stress exposures

Human pluripotent stem cells(h PSCs) represent heterogeneous populations, including induced pluripotent stem cells(i PSCs), endogenous plastic somatic cells, and embryonic stem cells(ESCs). Human ESCs are derived from the inner cell mass of the blastocyst, and they are characterized by the abilities to self-renew indefinitely, and to give rise to all cell types of embryonic lineage(pluripotency) under the guidance of the appropriate chemical, mechanical and environmental cues. The combination of these critical features is unique to h ESCs, and set them apart from other human cells. The expectations are high to utilize h ESCs for treating injuries and degenerative diseases; for modeling of complex illnesses and development; for screening and testing of pharmacological products; and for examining toxicity, mutagenicity, teratogenicity, and potential carcinogenic effects of a variety of environmental factors, including ionizing radiation(IR). Exposures to genotoxic stresses, such as background IR, are unavoidable; moreover, IR is widely used in diagnostic and therapeutic procedures in medicine on a routine basis. One of the key outcomes of cell exposures to IR is the change in gene expression, which may underlie the ultimate h ESCs fate after such a stress. However, gaps in our knowledge about basic biology of h ESCs impose a serious limitation to fully realize the potential of h ESCs in practice. The purpose of this review is to examine the available evidence of alterations in gene expression in human pluripotent stem cells after genotoxic stress, and to discuss strategies for future research in this important area.

Inhibition of human esophageal squamous cell carcinomas by targeted silencing of tumor enhancer genes: an overview

Esophageal cancer has been reported as the ninth most common malignancy and ranks as the sixth most frequent cause of death worldwide. Esophageal cancer treatment involves surgery, chemotherapy, radiation therapy, or combination therapy. Novel strategies are needed to boost the oncologic outcome. Recent advances in the molecular biology of esophageal cancer have documented the role of genetic alterations in tumorigenesis. Oncogenes serve a pivotal function in tumorigenesis. Targeted therapies are directed at the unique molecular signature of cancer cells for enhanced efficacy with low toxicity. RNA interference(RNAi) technology is a powerful tool for silencing endogenous or exogenous genes in mammalian cells. Related results have shown that targeting oncogenes with siRNAs, specifically the mRNA, effectively reduces tumor cell proliferation and induces apoptotic cell death. This article will briefly review studies on silencing tumor enhancer genes related to the induction of esophageal cancer.

XRCC1、XRCC3、ERCC2多态性与头颈部肿瘤患者放射性甲状腺功能异常风险的相关性

目的:探讨XRCC1、XRCC3、ERCC2多态性与头颈部肿瘤患者放射性甲状腺功能异常风险的相关性。方法:选择2019年5月~2020年12月于新疆维吾尔自治区人民医院行强调放射治疗的头颈部肿瘤患者120例作为研究对象。所有患者于放射治疗开始前收集临床资料,并抽取空腹静脉血对XRCC1、XRCC3、ERCC2多态性情况进行分析。强调放射治疗结束后进行为期1年的随访并统计随访期间出现甲状腺功能异常的情况。最后根据甲状腺功能异常情况对患者进行分组,分析XRCC1、XRCC3、ERCC2多态性与患者甲状腺功能异常的相关性。结果:异常组患者女性占比高于正常组(P<0.05)。异常组患者XRCC1单核甘酸多态性位点rs25487、rs1799782、XRCC3单核甘酸多态性位点rs861539及ERCC2单核甘酸多态性位点rs1799793基因型分布差异具有统计学意义(P<0.05)。异常组患者XRCC1单核甘酸多态性位点rs25487的G基因型频率、rs1799782的T基因型频率、XRCC3单核甘酸多态性位点rs861539的T基因型频率及ERCC2单核甘酸多态性位点rs1799793的T基因型频率高于正常组(P<0.05)。女性、XRCC1(rs25487、rs1799782)基因分型、XRCC3(rs861539)基因分型、ERCC2(rs1799793)基因分型均为放疗后甲状腺功能异常的独立影响因素(P<0.05)。结论:XRCC1、XRCC3、ERCC2基因多态性与头颈部肿瘤患者放射治疗后甲状腺功能损伤存在相关性,可以进一步探讨其作为放射后甲状腺功能异常预测因子的可能性。

桔梗过氧化物酶Ⅲ基因家族的鉴定及辐射后表达分析

为探究过氧化物酶Ⅲ(peroxidase classⅢ,PERs)基因家族在药用植物响应电离辐射中的作用,本试验研究了中药材桔梗的PERs(PgPERs)家族成员特性,及桔梗幼苗经高能重离子束和X射线辐射处理后PgPERs基因的表达量变化。通过序列比对、结构域鉴定和蛋白保守基序分析,共获得53个PgPERs,其蛋白的序列长度多数为258~621个氨基酸,碱性蛋白占多数。启动子区调控元件分析结果说明PgPERs存在多个与生长发育、植物激素和逆境胁迫相关的顺式作用元件。进化分析结果显示,PgPERs基因家族主要分为5个簇,与拟南芥过氧化物酶Ⅲ(AtPERs)有29对共线性关系。高能重离子束辐射桔梗幼苗后检测到3个PgPERs基因表达量上调,X射线辐射处理后有8个PgPERs基因差异表达。这些差异基因编码的蛋白质二级结构以α-螺旋和无规则卷曲为主,三级结构的相似度高,并含有跨膜螺旋。以上结果表明,不同类型的电离辐射处理桔梗幼苗后,其PgPERs响应机制并不相同。本研究结果为探究电离辐射影响桔梗生长发育和辐射响应过程提供了新的视角。

大分割电离辐射对鼻咽癌细胞共培养后的树突状细胞成熟状态的影响

目的研究大分割电离辐射对鼻咽癌(NPC)细胞与树突状细胞(DCs)共培养后DCs免疫表型和迁移能力的影响。方法核磁共振检测放化疗后NPC患者(NPC组)鼻咽部肿瘤变化,流式细胞术检测NPC组及健康志愿者(健康对照组)外周血DCs数量分群[髓系DCs(CD11c+myeloid DCs,MDCs)和浆系DCs(CD123+plasmacytoid DCs,PDCs)]情况;将DCs细胞分为未成熟树突状细胞组(imDCs组)、成熟DCs组(mDCs组)、imDCs+4 Gy组以及imDCs+18 Gy组,后两组是将imDCs与大分割电离辐射(4 Gy、18 Gy)照射后的NPC细胞共培养所得;流式细胞术、Transwell小室实验以及蛋白免疫印迹(Western blot)分别检测各组DCs免疫表型[人白细胞抗原DR(HLA-DR)、白细胞分化抗原(CD80)、CD83、CD86、CC基序趋化因子受体7(CCR7)]、细胞迁移能力以及细胞中环磷酸鸟苷-磷酸腺苷合成酶(cGAS)和干扰素基因刺激因子(STING)蛋白的表达。结果与放疗前相比,放疗后NPC组患者鼻咽黏膜稍增厚,肿瘤明显退缩,外周血中MDCs的数量明显减少(P<0.001);与imDCs组比较,imDCs+4 Gy组以及imDCs+18 Gy组中imDCs的免疫表型分子HLA-DR、CD80、CD83、CD86及CCR7的表达显著上调(P<0.001),且GAS和STING蛋白的表达增加(P<0.05);Transwell实验结果显示,DCs迁移能力随着电离辐射剂量的增加而增强(P<0.05)。结论经大分割电离辐射照射的NPC细胞可诱导imDCs向mDCs分化,这可能产生特异性的抗肿瘤免疫应答。

Mn-SOD对CHO细胞电离辐射敏感性的影响

近年来的研究发现 ,IL 1和TNF是重要的辐射防护因子 ,因IL 1和TNF都能选择性诱导Mn SOD的高度表达 ,因此认为Mn SOD可能有辐射防护作用 .通过转染有义和反义Mn SODcDNA于CHO细胞 ,进一步说明了Mn SOD在抗电离辐射损伤中的作用 .研究表明 ,转染有义Mn SODcDNA可降低细胞对电离辐射的敏感性 ,而转染反义Mn

利用基因芯片筛选辐射损伤早期生物标志物

以人外周血全血为研究对象,筛选本底值均一的辐射敏感基因,寻找辐射损伤早期的生物标志物。采集3名健康成人外周血,采用?-射线对其分别进行0、0.75、2和6 Gy照射,照射后2 h提取全血总RNA,利用全基因组芯片筛选差异表达基因,并分析差异表达基因在3个个体中的本底值。结果显示,共筛选到15个具有相对均一本底值的辐射诱导基因,这些基因照射后的变化具有一定的剂量依赖性:ISG20L1、TRAF4和TRIAP1等3个基因在0.75、2和6 Gy 3个剂量照射后2 h均上调2倍以上;LOC345537、POLH、SPIB、TNFSF9和TCL1A等5个基因在2 Gy和6 Gy照射后2 h变化2倍以上,其中TLC1A为下调表达,其余4个上调表达;C12orf5、DDB2、GADD45A、MADCAM1和RPS27L仅在6 Gy照射后2 h上调2倍以上。

重组人p53腺病毒注射液联合放 化疗对中晚期鼻咽癌消退率的影响

目的:探讨重组人p53腺病毒注射液在治疗鼻咽癌中,与放、化疗的协同作用。方法:病例分为两组:重组人p53腺病毒注射液局部治疗+同步放化疗组(A组)、同步放化疗组(B组)。观察内容:根据鼻内窥镜检查和CT检查1)原发灶消退时,放射剂量;2)放疗至40Gy时,原发灶消退情况;3)放疗结束时和治疗结束后3个月CT的影像结果。结果:原发灶消退时,A组放疗量较B组有所减小,但无统计学意义。放疗至40Gy和放疗结束时,原发灶消退情况A组和B组各有2例消退。放疗结束时,原发灶肿瘤缩小率:A组、B组间无明显差异。治疗结束后3个月,原发灶肿瘤缩小率为:A组(91.36±23.70)%;B组(64.66±39.18)%。A组较B组有明显提高。A组CR率较B组有明显提高。A组患者接受rAd-p53瘤体内注射,除了出现一过性发热外,未发现其它不良反应。结论:重组人p53腺病毒注射液行鼻咽癌局部治疗与放、化疗有明显的协同作用,可能对提高肿瘤消退率有很大的帮助,远期疗效尚需进一步随访研究。

X射线诱导人外周血淋巴细胞GADD45和p21基因表达上调

应用实时荧光逆转录聚合酶链反应(RT-PCR)方法,定量分析不同剂量X射线体外照射对人外周血淋巴细胞GADD45和p21基因表达的影响,探讨了运用mRNA水平变化作为电离辐射生物剂量计的可能性。结果表明:经1、2、3、5Gy X射线照射后24h,GADD45和p21基因表达均明显上调。GADD45基因表达在1-5Gy照射剂量范围内呈指数相关。p21基因表达在1-3Gy照射剂量范围内呈线性剂量效应关系,但5.0Gy照射后,其表达不再继续增加。结果表明,X射线照射后人外周血淋巴细胞GADD45和p21基因的表达在一定剂量范围内呈剂量依赖性上调,GADD45更适合发展为核事故受照射人员的分子生物剂量计。

鹿角脱盘对辐射诱发小鼠胸腺淋巴瘤Notch2基因表达和免疫功能的影响

目的:观察鹿角脱盘对辐射诱发小鼠胸腺淋巴瘤Notch2基因的表达和免疫功能的影响,探讨其在辐射致癌过程中的作用。方法:将90只近交系BALB/c小鼠随机分成对照组、照射组和照射给药组,每组30只。照射组和照射给药组小鼠采用X射线照射,建立胸腺淋巴瘤动物模型,照射后给予照射给药组小鼠喂饲含鹿角脱盘超微粉的鼠粮。6个月后,取全血和胸腺,采用RT-PCR和Western blotting法分别检测胸腺淋巴瘤组织中Notch2mRNA和蛋白表达水平;采用ELISA法检测血清免疫球蛋白(IgG、IgA和IgM)水平,应用SOD试剂盒检测血清中SOD活性。结果:照射组和照射给药组小鼠胸腺瘤发生率分别为53.33%(16/30)和36.67%(11/30);照射组小鼠胸腺瘤组织中Notch2mRNA和蛋白表达水平较对照组小鼠正常胸腺组织均明显升高(P<0.05),而照射给药组小鼠胸腺瘤组织中Notch2 mRNA和蛋白表达水平均低于照射组(P<0.05);照射组小鼠血清中IgG、IgA和IgM水平均低于对照组(P<0.05),而照射给药组小鼠血清中IgG、IgM和血红蛋白水平及SOD活性均高于照射组(P<0.05)。结论:电离辐射激活Notch2基因和蛋白的高表达及降低小鼠免疫功能可能是辐射诱发胸腺淋巴瘤的发生机制之一;鹿角脱盘可通过抑制Notch2基因和蛋白的表达及提高小鼠免疫功能而降低辐射致癌的发生率,起到抑制肿瘤的作用。