p53-independent apoptosis induced by genistein in lung cancer cells.

Lung cancer is the leading cause of cancer-related deaths in the world, with increasing incidence in many developed countries. Epidemiological data suggest that consumption of soy products may be associated with a decreased risk of cancer. Despite the association of nutrition and cancer, the molecular mechanisms by which the active metabolite in the soy diet, genistein, exerts its biological response have not been studied. We previously showed that genistein can inhibit the growth of H460 non-small-cell lung cancer (NSCLC) cells in vitro. To explore the molecular mechanisms by which genistein inhibits the growth of NSCLC cells, we investigated cell growth inhibition, modulation in gene expression, and induction of apoptosis by genistein in H460 cells, which harbor wild-type p53, and H322 cells, which possess mutated p53. Genistein was found to inhibit H460 and H322 cell growth in a dose-dependent manner. Staining with 4,6-diamidino-2-phenylindole, poly(ADP-ribose) polymerase cleavage, and flow cytometric apoptosis analysis were used to investigate apoptotic cell death, and the results show that 30 microM genistein causes cell death via a typical apoptotic pathway. Western blot analysis demonstrated upregulations of p21WAF1 and Bax by genistein in wild-type and mutant p53 cell lines. Furthermore, cells treated with genistein showed an increased expression of endogenous wild-type p53, while the level of the mutant p53 protein remained unchanged. From these results, we conclude that genistein induces apoptosis in NSCLC cells through a p53-independent pathway and, thus, may act as an anticancer agent.     

High LET radiation enhances nocodazole Induced cell death in HeLa cells through mitotic catastrophe and apoptosis

To understand how human tumor cells respond to the combined treatment with nocodazole and high LET radiation, alterations in cell cycle, mitotic disturbances and cell death were investigated in the present study. Human cervix carcinoma HeLa cells were exposed to nocodazole for 18 h immediately followed by high LET iron ion irradiation and displayed a sequence of events leading to DNA damages, mitotic aberrations, interphase restitution and endocycle as well as cell death. A prolonged mitotic arrest more than 10 h was observed following nocodazole exposure, no matter the irradiation was present or not. The occurrence of mitotic slippage following the mitotic arrest was only drug-dependent and the irradiation did not accelerate it. The amount of polyploidy cells was increased following mitotic slippage. No detectable G(2) or G(1) arrest was observed in cells upon the combined treatment and the cells reentered the cell cycle still harboring unrepaired cellular damages. This premature entry caused an increase of multipolar mitotic spindles and amplification of centrosomes, which gave rise to lagging chromosomal material, failure of cytokinesis and polyploidization. These mitotic disturbances and their outcomes confirmed the incidence of mitotic catastrophe and delayed apoptotic features displayed by TUNEL method after the combined treatment. These results suggest that the addition of high-LET iron ion irradiation to nocodazole enhanced mitotic catastrophe and delayed apoptosis in HeLa cells. These might be important cell death mechanisms involved in tumor cells in response to the treatment of antimitotic drug combined with high LET radiation.     

DNA依赖蛋白激酶抑制剂对1,4-苯醌诱导的非p53依赖的HL60细胞凋亡的影响

目的 探讨DNA依赖蛋白激酶(DNA-PK)抑制剂NU7026和渥曼青霉素(Wortmannin)对1,4-苯醌(1,4-BQ)诱导的人早幼粒白血病细胞(HL60)细胞凋亡的影响.方法 HL60细胞分为染毒组(0、5、10、25和50μmol/L1,4-BQ染毒24 h)和NU7026 、Wortmannin预处理组(10μmol/L NU7026、25μmol/L Wortmannin分别预处理1h后以0、5、10、25和50 μmol/L 1,4-BQ染毒24 h),用流式细胞仪Annexin V/PI双染法和DNA Ladder法分析检测细胞凋亡水平.将HL60细胞分为空白对照组、NU7026处理组(10 μmol/L)、Wortmannin处理组(25 μmol/L)、1,4-BQ染毒组(10 μmol/L)、NU7026+1,4-BQ组(10μmol/L NU7026预处理1h,以10 μmol/L 1,4-BQ染毒24 h),25 μmol/L Wortmannin+1,4-BQ组(25μmol/L Wortmannin预处理1h,以10 μmol/L 1,4-BQ染毒24 h),用real-time PCR法检测Bax mRNA基因表达;蛋白免疫印迹法(Western blot)检测HL60细胞的p53蛋白表达.结果 流式细胞仪Annexin V/PI双染法结果显示,NU7026+10 μmol/L 1,4-BQ处理组细胞凋亡率为17.6％±1.19％,Wortmannin+ 10μmol/L 1,4-BQ处理组细胞凋亡率为15.2％±1.22％,两组细胞凋亡率均高于10 μmol/L 1,4-BQ染毒组(6.3％±1.04％);NU7026+25tμmol/L1,4-BQ处理组细胞凋亡率为46.2％±3.55％,Wortmannin+25 μmol/L1,4-BQ处理组细胞凋亡率为26.9％±2.62％,两组细胞凋亡率均明显高于25 μmol/L 1,4-BQ染毒组(14.1％±1.54％);NU7026+50 μmol/L1,4-BQ处理组细胞凋亡率为61.8％±1.78％,明显高于50 μmol/L1,4-BQ染毒组(35.9％±4.51％),以上各组的差异均有统计学意义(P＜0.05).DNA Ladder法结果与流式细胞仪检测数据基本一致.与NU7026组和1,4-BQ染毒组比较,NU7026+1,4-BQ组Bax mRNA表达水平升高;与Wortmannin组和1,4-BQ组比较,Wortmannin+1,4-BQ组Bax mRNA表达水平升高,差异均有统计学意义(P＜0.05).Western blot检测HL60细胞不表达p53蛋白.结论 DNA-PK抑制剂NU7026和Wortmannin促进1,4-BQ诱导的非p53依赖的HL60细胞凋亡.     

Lycopene differentially induces quiescence and apoptosis in androgen-responsive and -independent prostate cancer cell lines

BACKGROUND & AIMS: Lycopene has been credited with a number of health benefits including a decrease in prostate cancer risk. Our study investigates the molecular mechanism underlying anti-cancer activity of lycopene-based products in androgen-responsive (LNCaP) and androgen-independent (PC3) cells. METHODS: The effect of lycopene-based agents on prostate cancer growth and survival were examined using proliferation assays, bromodeoxyuridine incorporation and flow cytometric analysis of cellular DNA content. Biochemical effects of lycopene treatment were investigated by immunoblotting for changes in the absolute levels and phosphorylation states of cell cycle regulatory and signalling proteins. RESULTS: LNCaP and PC3 cells treated with the lycopene-based agents undergo mitotic arrest, accumulating in G0/G1 phase. Immunoblot screening indicated that lycopene's antiproliferative effects are likely achieved through a block in G1/S transition mediated by decreased levels of cyclins D1 and E and cyclin dependent kinase 4 and suppressed Retinoblastoma phosphorylation. These responses correlated with decreased insulin-like growth factor-I receptor expression and activation, increased insulin-like growth factor binding protein 2 expression and decreased AKT activation. Exposure to lycopene at doses as low as 10 nM for 48 h induced a profound apoptotic response in LNCaP cells. In contrast PC3 cells were resistant to apoptosis at doses up to 1 microM. CONCLUSIONS: Lycopene exposure can suppress phosphatidylinositol 3-kinase-dependent proliferative and survival signalling in androgen-responsive LNCaP and androgen-independent PC3 cells suggesting that the molecular mechanisms for the cytostatic and cytotoxic actions of lycopene involve induction of G0/G1 cell cycle arrest. This study supports further examination of lycopene as a potential agent for both the prevention and treatment of prostate cancer.     

Hypergravity induces phosphorylation of p53 at serine 15, but not an expression of p53-downstream genes

We investigated the p53 signaling pathway induced by hypergravity in the human glioblastoma cell line A172. Hypergravity (20 x g) induced the accumulation of p53 and the phosphorylation of p53 at Ser-15. The phosphorylation of p53 with hypergravity was not inhibited by wortmannin, the PI3-kinase inhibitor. This indicated that the p53 signal pathway induced by hypergravity is different from other p53 signal pathways, such as that of the DNA damage signal. Hypergravity did not induce an expression of the genes Waf-1 or Bax, located downstream from p53. We also examined the expression of genes with hypergravity by using a DNA microarray containing oligo DNA from 30,000 human genes. Hypergravity (20 x g, 6 h) did induce the expression of some genes concerned with the cell signaling pathway and cytoskeleton of the cell, but not any of the p53-downstream genes. DNA microarray revealed the induction of many genes to enable the cells to adapt to the hypergravity environment.     

Involvement of p53-dependent apoptosis in radiation teratogenesis and in the radioadaptive response in the late organogenesis of mice

The irradiation of fetuses at the late period of organogenesis has been known to induce a dramatic increase in malformations. The mechanisms involved, however, have remained unclear for a long time. Using the mouse limb bud system, we first found that radiation-induced apoptosis is involved in the malformation, namely, radiation-induced apoptosis in the predigital regions of embryonic limb buds is responsible for digital defects in mice. An examination of embryonic C57BL/6J mice with different p53 (trp53) status enabled us to further find that susceptibility to radiation-induced apoptosis in the predigital regions and digital defects depend on both the p53 status and the radiation dose; p53 wild-type mice appeared to be the most sensitive, while p53 knockout mice were the most resistant. These results indicate that p53-dependent apoptosis mediates radiation-induced digital defects in the later organogenesis period. The existence of a radioadaptive response in embryonic mice, which has not been reported so far, was found by irradiating embryos with either 5 cGy or 30 cGy on embryonic day 11 prior to a challenging irradiation at 3 Gy on embryonic day 12. p53-heterozygous embryos did not show the radioadaptive response, indicating the involvement of p53 in the radioadaptive response in embryogenesis.     

酒精性股骨细胞凋亡及其p53等基因的表达

目的　探讨细胞凋亡抑癌基因 (p5 3)和细胞凋亡抑制基因 (Bcl 2 )基因在酒精性股骨头缺血性坏死骨细胞凋亡中的作用。方法　家兔 6 0只 ,随机分为 2组。灌胃法建模 ,实验组给予含乙醇 5 0 %的烈性白酒 8ml/ (kg·d) ,对照组给予等量生理盐水 ,1～ 6个月分批处死。原位末端标记法 (TUNEL法 )检测骨细胞凋亡 ,免疫组化检测 p5 3和Bcl 2基因表达。结果　第 2 ,3,6个月 ,实验组出现大量骨细胞凋亡 ,以软骨下区最为明显 ,骨细胞凋亡数明显高于对照组 (P <0 0 1) ;两组间骨细胞Bcl 2基因阳性细胞数、p5 3基因阳性细胞数均有显著性差异 (P <0 0 1) ,实验组骨细胞Bcl 2基因阳性细胞数与细胞凋亡数成明显负相关性 (r=- 0 75 ,P <0 0 1) ,实验组骨细胞 p5 3基因阳性细胞数与细胞凋亡指数呈明显正相关性 (r=0 6 8,P <0 0 1)。结论　酒精性ANFH中骨细胞存在明显凋亡现象 ,且受 p5 3基因上调与Bcl 2基因下调影响 ,p5 3与Bcl 2共同调节骨细胞凋亡。     

p53-dependent delayed effects of radiation vary according to time of irradiation of p53 + / ? mice

We previously reported that in p53 ^{+ / −} mice that had been given a whole-body dose of 3 Gy at 8 weeks of age, p53-dependent delayed effects of radiation, as manifested in T-cell receptor (TCR) variant fractions (VF) instability in mouse splenocytes, were biphasic, namely, induction of TCR-VF mutation reappeared at 44 weeks. The manifestation of the delayed effects and the measures of biological markers varied according to the timing of irradiation. We also reported that the decrease in function of the p53 gene was related to the effects of a delayed mutation. In the present study, we investigated the functions and mutations of the p53 gene in old age for p53 ^{+ / −} mice following irradiation at various ages. p53 ^{+ / −} mice were given a whole-body dose of 3 Gy at 8, 28 or 40 weeks of age. There were significant differences for all variables tested at 8 weeks of age. This was similarly the case for mice irradiated at 28 weeks of age, in which there were also significant differences in TCR VF and the percentage of apoptosis. In mice irradiated at 40 weeks of age, there were significant differences for all considered variables except for the p53 allele. We demonstrated that the different patterns of delayed mutation of the p53 gene at 56 weeks of age depended on the age at which mice had undergone 3-Gy whole-body irradiation. Our conclusions are limited to variation in p53-dependent delayed effects according to the time of irradiation.     

p53-Bax线粒体凋亡通路DNA甲基化与胆管癌病理生物学的关系

目的探讨p53-Bax线粒体凋亡通路抑癌基因启动子区的甲基化状态与胆管癌病理生物学行为的关系。方法采用甲基化PCR检测36例胆管癌患者癌组织和癌旁组织中抑癌基因甲基化诱导静止基因（TMS1／ASC）、死亡相关蛋白激酶（DAPK）和p14启动子区甲基化状态,并对p53基因外显子5～8进行DNA测序,分析以上基因的突变与胆管癌生物学行为的关系。结果24例（66．7％）胆管癌患者癌组织中至少有1个抑癌基因启动子区存在甲基化,p14、DAPK和TMS1／ASC的甲基化率分别为25％、30．6％和36．1％。5例（13．9％）患者的癌旁组织中存在抑癌基因启动子区甲基化,其中TMS1／ASC启动子区甲基化3例（8．3％）,DAPK启动子区甲基化2例（5．6％）。DNA测序显示,22例（61．1％）胆管癌患者癌组织中p53基因外显子5～8存在突变。其中14例（38．9％）p53基因外显子突变伴1个以上抑癌基因启动子区甲基化,与胆管癌的病理类型、浸润深度、分化程度显著相关（P〈0．05）。抑癌基因非甲基化及p53突变阴性组（4例）术后1、2、3年的生存率分别为70％、43％、28％,抑癌基因甲基化及p53突变阳性组（14例）术后1、2、3年的生存率分别为28％、5％、0％,前者的生存率显著高于后者（X^2=9．060,P=0．03）。结论p53-Bax线粒体凋亡通路中抑癌基因启动子过甲基化是胆管癌组织中常见的分子事件,癌旁组织中TMS1／ASC和DAPK基因甲基化程度虽然较低,但可能对胆管癌有早期诊断意义。p53突变伴抑癌基因甲基化与胆管癌的病理生物学行为有关,趋向于较高的恶性程度和较低的生存率。     

Lycopene supplementation prevents smoke-induced changes in p53, p53 phosphorylation, cell proliferation, and apoptosis in the gastric mucosa of ferrets

Cigarette smoking increases the risk for gastric cancer. Higher intakes or blood levels of lycopene are associated with a decreased risk of gastric cancer. However, the biological mechanisms by which lycopene may protect against gastric carcinogenesis are poorly understood. We evaluated the effects of lycopene supplementation on smoke-induced changes in protein levels of p53, p53 target genes (p21(Waf1/Cip1) and Bax-1), cell proliferation, and apoptosis in the gastric mucosa of ferrets. Ferrets were assigned to cigarette smoke exposure or to no exposure and to no, low-dose, or high-dose lycopene supplementation (2 x 3 factorial design) for 9 wk. Lycopene concentrations were significantly elevated in a dose-dependent manner in the gastric mucosa of ferrets supplemented with lycopene alone, but were markedly reduced in ferrets supplemented with lycopene and exposed to smoke. Although ferrets were given lycopene containing 95% all-trans isomers, cis isomers were the predominant forms in the gastric mucosa. Total p53 and phosphorylated p53 levels were greater in ferrets exposed to smoke alone than in all other groups. Levels were approximately 300 and 500% of the controls, respectively. However, smoke-elevated total p53 and phosphorylated p53 were markedly attenuated by both doses of lycopene. p21(Waf1/Cip1), Bax-1, and cleaved caspase 3 were substantially decreased, whereas cyclin D1 and proliferating cellular nuclear antigen (PCNA) were increased in ferrets exposed to smoke alone. Lycopene prevented smoke-induced changes in p21(Waf1/Cip1), Bax-1, cleaved caspase 3, cyclin D1, and PCNA in a dose-dependent fashion. These data indicate that lycopene may prevent smoke exposure-induced changes in p53, p53 phosphorylation, p53 target genes, cell proliferation, and apoptosis in the gastric mucosa of ferrets.     

cdk5、p35和p53基因在砷诱导的神经细胞凋亡中的改变

目的 研究cdk5、p35和p53基因表达量在As2O3诱导的神经细胞凋亡中的改变,为探讨As2O3神经毒性的机制提供基础资料.方法 将原代培养的大鼠神经元分为未处理对照组,DMSO溶剂对照组,1、5、10 μmol/L As2O3染毒组,分别用1、5、10 μmol/L As2O3溶液染毒,未处理对照组只加入培养液.染毒8h后,用四甲基偶氮唑蓝(MTT)法检测神经细胞活力,用流式细胞仪检测神经细胞凋亡率,实时荧光定量聚合酶链反应(PCR)法检测cdk5、p35、p53基因的表达.结果 1、5、10 μmol/L As2O3染毒组神经细胞活力抑制率分别为16.77％、19.72％、27.81％.与未处理对照组和溶剂对照组相比,5和10μmol/L As2O3染毒组细胞凋亡率明显增加,差异有统计学意义(P＜0.05).各染毒组cdk5、p35、p53基因的表达量随着染毒剂量的增加而升高,各组间p35基因表达量的差异无统计学意义(P＞0.05);cdk5和p53基因表达量的组间差异有统计学意义(P＜0.05),5和10 μmol/L As2O3染毒组cdk5基因表达量明显高于未处理对照组和溶剂对照组,差异有统计学意义(P＜0.05);1、5和10 μmol/L As2O3染毒组p53表达量明显高于未处理对照组,差异有统计学意义(P＜0.05);其中10 μmol/L As2O3染毒组p53基因表达量明显高于DMSO溶剂对照组,差异有统计学意义(P＜0.05).结论 cdk5、p35和p53可能参与了As2O3诱导的神经细胞凋亡过程.     

Zinc deficiency induces oxidative DNA damage and increases p53 expression in human lung fibroblasts

Poor zinc nutrition may be an important risk factor in oxidant release and the development of DNA damage and cancer. Approximately 10% of the United States population ingests <50% of the recommended daily allowance for zinc, a cofactor in proteins involved in antioxidant defenses, electron transport, DNA repair and p53 protein expression. This study examined the effects of zinc deficiency on oxidative stress, DNA damage and the expression of DNA repair enzymes in primary human lung fibroblasts by the use of DNA microarrays and functional assays. Cellular zinc was depleted by 1) growing cells in a zinc-deficient medium and 2) exposuring cells to an intracellular zinc chelator, N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine. Array data revealed upregulation of genes involved in oxidative stress and DNA damage/repair and downregulation of other DNA repair genes. Zinc deficiency in cells caused an increase in oxidant production (dichlorofluoroscein fluorescence) and a significant induction of single-strand breaks (Comet assay) and p53 protein expression (Western blot analysis). Thus, zinc deficiency not only caused oxidative stress and DNA damage, but also compromised the cells' ability to repair this damage. Zinc adequacy appears to be necessary for maintaining DNA integrity and may be important in the prevention of DNA damage and cancer.     

Dose and dose-rate effects of X rays and fission neutrons on lymphocyte apoptosis in p53(+/+) and p53(-/-) mice

Following the exposure of mice to X rays or fission neutrons, the frequency (F) of apoptosis was measured after 4 h, and the weight loss or lymphocyte content loss in the thymus and spleen was measured after 24 h. In p53(+/+) mice, F increased linearly with the dose (D (Gy)) and the induced rate per Gy of F (detected by TUNEL staining) was 0.05 and 0.23 for X rays and fission neutrons, respectively. Therefore, the RBE of fission neutrons was 4.6 for apoptosis induction. This indicates that radiation-induced apoptosis is mostly due to double strand breaks (DSBs) in DNA because we previously obtained almost the same RBE value of fission neutrons for the induction of crossover mutations in Drosophila melanogaster, which arise from the recombinational repair of DSBs. In p53(+/+) mice, decreases in the organ weight and the lymphocyte content were observed for the thymus and the spleen 24 h after X-irradiation. These atrophic changes in the thymus and the spleen quantitatively corresponded to the total apoptotic cell deaths occurring in them. However, in p53(-/-) mice, no vigorous apoptosis was induced after X-irradiation, and hyperplastic changes in the weight and the lymphocyte content appeared in the thymus and the spleen 24 h after X-irradiation. In p53(+/+) mice, there was no difference in the induced rate per Gy of reduction in the surviving fraction of lymphocytes between acute (0.4 Gy/min) and chronic (3 mGy/min) gamma-irradiations. Namely, radiation-induced apoptosis in lymphocytes is a dose-rate independent event.     

Free radical scavenger edaravone suppresses x-ray-induced apoptosis through p53 inhibition in MOLT-4 cells

Edaravone, a clinical drug used widely for the treatment of acute cerebral infarction, is reported to scavenge free radicals. In the present study, we investigated the radioprotective effect of edaravone on X-ray-induced apoptosis in MOLT-4 cells. Apoptosis was determined by the dye exclusion test, Annexin V binding assay, cleavage of caspase, and DNA fragmentation. We found that edaravone significantly suppressed the X-ray-induced apoptosis. The amount of intracellular ROS production was determined by the chloromethyl-2',7'-dichlorodihydro-fluorescein diacetate system. We found that the intracellular ROS production by X-irradiation was completely suppressed by the addition of edaravone. The accumulation and phosphorylation of p53 and the expression of p21(WAF1), a target protein of p53, which were induced by X-irradiation, were also suppressed by adding edaravone. We conclude that the free radical scavenger edaravone suppresses X-ray-induced apoptosis in MOLT-4 cells by inhibiting p53.     

Chronic alcohol consumption induces genomic but not p53-specific DNA hypomethylation in rat colon.

Alcohol consumption has been implicated as an etiologic agent in colorectal carcinogenesis, but the mechanism by which alcohol enhances the development of colorectal cancer is not yet known. Recent reports indicate that alcohol consumption can diminish cellular S-adenosylmethionine levels, thus possibly altering normal patterns of DNA methylation, a phenomenon that is mediated by S-adenosylmethionine and whose abnormalities are observed in colonic neoplasia. This study investigated the effect of chronic alcohol consumption on genomic DNA methylation of rat colonic epithelium and methylation of the p53 tumor suppressor gene, abnormalities of which have been implicated in colonic carcinogenesis. Two groups of rats (n = 10/group) were pair-fed either an alcohol-containing or an isocaloric control Lieber-DeCarli diet for 4 wk. The extent of genomic DNA methylation was assessed by incubating the extracted DNA with [(3)H]S-adenosylmethionine and Sss1 methyltransferase. Gene-specific methylation was assessed by using semiquantitative polymerase chain reaction (PCR). Tritiated methyl uptake by colonic DNA (which is inversely correlated with genomic methylation) from alcohol-fed rats was 57% less than that in control DNA (P < 0.05). However, gene-specific DNA methylation, both in the p53 gene (exons 5-8) and in the beta-actin gene, a control gene, did not differ between the two groups. In conclusion, this study indicates that chronic alcohol consumption produces genomic DNA hypomethylation in the colonic mucosa. This may constitute a means by which carcinogenesis is enhanced, although further studies are required to establish causality.     

Identification of proteins that regulate radiation-induced apoptosis in murine tumors with wild type p53

In this study, we investigated the molecular factors determining the induction of apoptosis by radiation. Two murine tumors syngeneic to C3H/HeJ mice were used: an ovarian carcinoma OCa-I, and a hepatocarcinoma HCa-I. Both have wild type p53, but display distinctly different radiosensitivity in terms of specific growth delay (12.7 d in OCa-I and 0.3 d in HCa-I) and tumor cure dose 50% (52.6 Gy in OCa-I and > 80 Gy in HCa-I). Eight-mm tumors on the thighs of mice were irradiated with 25 Gy and tumor samples were collected at regular time intervals after irradiation. The peak levels of apoptosis were 16.1 +/- 0.6% in OCa-I and 0.2 +/- 0.0% in HCa-I at 4 h after radiation, and this time point was used for subsequent proteomics analysis. Protein spots were identified by peptide mass fingerprinting with a focus on those related to apoptosis. In OCa-I tumors, radiation increased the expression of cytochrome c oxidase and Bcl2/adenovirus E1B-interacting 2 (Nip 2) protein higher than 3-fold. However in HCa-I, these two proteins showed no significant change. The results suggest that radiosensitivity in tumors with wild type p53 is regulated by a complex mechanism. Furthermore, these proteins could be molecular targets for a novel therapeutic strategy involving the regulation of radiosensitivity.     

甘肃省某医院重离子放射工作人员个人剂量监测结果分析

对2018—2021年甘肃省某医院重离子放射工作相关人员个人剂量进行监测。结果显示，监测人员个人受照剂量均低于医院规定的管理目标值；经Fisher''s精确检验，临床工作人员与运行维护人员个人剂量分布比差异均无统计学意义（P>0.05）。医院仍需进一步加强重离子相关工作人员的职业素养和防护意识，完善医院内部监督管理制度。