Bone Healing Following Irradiation During Tourniquet Ischaemia

The bone harvest chamber (BHC) methodology, a titanium implant for quantitative evaluations of bone healing, was used in order to investigate the radioprotective function of anoxia, in healing bone tissue. After incorporation of one BHC in each proximal tibial metaphysis of a rabbit it was possible to collect newly formed bone specimens in 3-week-periods without animal sacrifice. The amount of bone was determined by microradiography and densitometry. Ten animals divided into 2 groups were used. One group receiving a single dose of 25 Gy during tourniquet ischaemia was compared with another receiving the same dose during normal blood perfusion. A significantly improved bone healing response was seen in the ischaemic group, with a tendency to further improvement with increasing time after irradiation.     

Bone Cell Viability After Irradiation: An enzyme histochemical study

Adult rabbits were irradiated to one proximal tibial metaphysis while the contralateral tibia served as a control. Each animal was thus its own control. Single doses of 15, 25 and 40 Gy ⁶⁰Co were used. The follow-up time was 11 to 22 weeks after irradiation. A histochemical method, recording diaphorase (NADH₂ and NADPH₂) activity in osteocytes, was employed. This method is regarded as superior to conventional histology. No evidence of osteocyte death was found even after 22 weeks following 40 Gy irradiation. This is interpreted as an indication that the osteocytes, which are end stage cells, are relatively radioresistant.     

低剂量辐射对HCT-8大肠癌细胞周期的影响

目的 采用低剂量辐射免疫兴奋效应的动物模型,探讨低剂量X射线照射对人大肠癌HCT-8细胞株细胞周期的影响.方法 采用流式细胞术(FCM)检测大肠癌细胞周期.结果 低剂量电离辐射照射后,大肠癌G0/G1期细胞百分数升高(P＜0.05),S期细胞百分数降低(P＜0.05),G2 M期细胞百分数升高(P＜0.05).结论 低剂量电离辐射可抑制大肠癌细胞的DNA合成及增殖.     

Early Effects of Preoperative Irradiation Upon the Cell Cycle Composition in Rectal Adenocarcinomas a Flow-Cytometric DNA Investigation

The DNA patterns were studied by means of flow cytometric analysis in 43 rectal adenocarcinomas. Ploidy level and cell cycle distribution were related to clinical stage and histopathology. The frequency of grossly aneuploid tumours and tumours with multiple aneuploid cell populations increased with more advanced clinical stages and with the degree of dedifferentiation. In 15 cases the DNA pattern was studied before and after preoperative irradiation. The ploidy level was not affected by irradiation. A pronounced increase in the proportion of G₂ cells was found after irradiation. This G₂ blockage was proportional to the amount of S-phase cells before irradiation. Since following irradiation the proportion of S-phase cells was low and the proportion of G₁ cells unchanged, the existence of a high fraction of resting G₁ tumour cells can be assumed.     

The Effect of Glycolysis Inhibitors on The recovery Of Cho-K1 Cells from Split-Dose Irradiation

The survival and recovery of CHO-K 1 cells exposed to three inhibitors of different glycolytic enzymes was studied. All enzymes have previously been shown to reduce survival by acting on the survival curve shoulder. Split dose recovery, however, was increased when cells were treated with sodium iodoacetate or with sodium arsenate but decreased with sodium fluoride. The effect with the first two compounds was similar to that observed under similar conditions with glucose analogues, lactate, or ox-amate and suggest that glycolytic energy metabolism is a factor in both survival and recovery of these cells from radiation.     

长春新碱对鼻咽癌细胞增殖和周期的影响

[目的]探讨长春新碱(VCR)对鼻咽癌CNE鄄2Z细胞增殖和周期的影响。[方法]MTT法检测增殖抑制率和IC50,流式细胞术分析细胞周期。[结果]不同浓度的VCR分别处理细胞24h、48h、72h时,抑制率随浓度的增加和时间的延长而增加,其IC50分别为(2.01±0.26)、(1.59±0.23)、(0.92±0.11)μg/ml,各IC50间的差异有非常显著性意义(P<0.01)。0.5μg/ml、1μg/ml、2μg/mlVCR分别处理细胞6h、12h、24h时,G0/G1期细胞明显下降,G2/M期细胞明显升高,随时间的延长变化更明显(P<0.01)。[结论]VCR对CNE鄄2Z细胞具有增殖抑制作用,该抑制作用具有剂量和时间依赖性;阻滞细胞于G2/M期,此阻滞作用具有时间依赖性;一定剂量的VCR可能通过阻滞CNE鄄2Z于G2/M期而抑制其增殖。     

Delivery of Cell Cycle Genes to Block Astrocytoma Growth

Current therapies for glioblastoma multiforme are ineffective. Therefore, novel therapies that target specific differences between normal and malignant cells are urgently needed. Abnormalities of cell-cycle related genes are a common feature of cancer in general and astrocytic tumors in particular. The role of these proteins is to help to regulate cell proliferation, differentiation and apoptosis. Restoring wild-type activity of critical regulators of the cell cycle to astrocytic tumors generally results in modification of the growth properties, and often the viability, of the cancer cells. Transfer of p53 induces growth arrest and, more importantly, apoptosis. Restoration of the Rb pathway results in either reversible growth arrest or senescence. Expression of E2F-1 induces transient increase of proliferation followed by massive apoptosis. Overexpression of MMAC/PTEN arrests cell cycle progression in G1 and promotes anoikis. Current knowledge of the functions of these cell-cycle controllers can be used to design small peptides and drugs to induce cell-cycle related anti-cancer effect. Inactivation of the p53 and Rb pathways in cancer cells is also being used to engineer mutant viruses that are able to replicate exclusively in cancerbreak cells.     

电离辐射对血管内皮细胞和PC-3细胞增殖和凋亡的影响

目的 探讨不同剂量X射线照射对原代人脐静脉内皮细胞(HUVEC)和PC-3细胞周期和凋亡的影响,为临床放疗提供理论依据。方法 采用形态学观察和Annexin V-FITC联合PI双染法和ApO2.7单抗法流式细胞仪(FCM)定量检测原代HUVEC和PC-3细胞在0-10 Gy的6MV-X射线照射后细胞周期和凋亡的变化。结果 照射后24 h和48 h两种细胞均出现明显G0/G1期减少和G2/M期增加,但2 Gy照射时仅对PC-3细胞周期有影响;两种细胞照射后均未出现辐射相关的凋亡。结论 电离辐射可诱导两种细胞出现G2/M期阻滞但不引起凋亡发生,两种细胞均有一定的辐射抗拒性。     

二烯丙基二硫对人结肠癌HT-29细胞周期的阻滞作用

[目的]探讨二烯丙基二硫(DADS)对人结肠癌HT-29细胞周期的阻滞作用及其分子机制.[方法]应用MTF法及细胞计数法测量HT-29细胞生长抑制,流式细胞术检测细胞时相分布,免疫细胞法测定p21、C-myc、Cyclin E表达.[结果]MTT法显示,不同浓度DADS作用HT-29细胞12、24、48h后,细胞生长抑制率及细胞群体倍增时间呈浓度、时间依赖性增加.流式细胞仪分析,30、60pmol/LL DADS阻滞HT29细胞在G1期,与对照组相比,可使G1期细胞增加约2倍,而90、120μmol/L DADS显著地将细胞阻滞在G2/M期.免疫细胞化学分析表明在细胞周期阻滞的同时有p21wafl蛋白表达上调,Cyclin E、C-myc蛋白表达下降.[结论]DADS对HT-29细胞的抑制增殖作用可能与细胞周期阻滞有关,DADS对HT-29细胞周期阻滞的分子机制可能与调节p21wafl、Cyclin E、C-myc表达相关.     

低剂量辐射对肿瘤细胞凋亡、细胞周期以及凋亡相关蛋白 Bcl-2的影响(英文)

目的探讨低剂量辐射对小鼠移植肿瘤细胞的凋亡、细胞周期以及 Bcl-2的影响。方法昆明种雄性小鼠左后肢腹股沟皮下接种 S180肉瘤细胞,接种后7天γ射线全身照射75mGy,照射后24、48小时分别处死直接测量肿瘤大小变化,取肿瘤组织分别进行流式细胞仪分析凋亡、细胞周期以及免疫组化染色半定量分析凋亡相关蛋白 Bcl-2表达的变化。结果与直接荷瘤组相比,低剂量照射组肿瘤生长缓慢(P<0.05),24小时后肿瘤细胞阻滞于 G1期,Bcl-2蛋白表达下降,48小时后肿瘤细胞凋亡增加(P<0.001)。结论低剂量辐射可使机体肿瘤细胞阻滞于 G1期并通过凋亡相关蛋白表达变化导致肿瘤细胞凋亡增加,明显提高机体抗肿瘤的作用,具有肿瘤治疗和辅助放化疗的实际临床意义。     

Bracken-fern Extracts Induce Cell Cycle Arrest and Apoptosis in Certain Cancer Cell Lines

Bracken fern [Pteridium aquilinem (L.) kuhn (Dennstaedtiaceae)] is one of the most common species on the planet. It has been consumed by humans and animals for centuries. Use by some human groups is because theybelieve bracken fern is good for health as plant medicine. However, it is also one of the few known plants that can cause tumors in farm animals. Many interested groups have focused their attention on bracken fern because of these interesting features. In order to evaluate the biological effects of exposure to this plant in cellular level, human cancer cell lines were treated with the fern dichloromethane extracts and the genotoxic and cytotoxic effects were studied. Anti-proliferative/cytotoxic effects were evaluated by cell count, MTT assay and flow cytometry methods with three different cancer cell lines, TCC, NTERA2, and MCF-7, and two normal cells, HDF1 and HFF3. Pro-apoptotic effects of the extracts were determined by DAPI staining and comet assay, on TCC cancercells compared to the normal control cell lines. Cellular morphology was examined by light microscopy. Our present study showed that the extract caused DNA damage and apoptosis at high concentrations (200 μg/mL)and also it may induce cell cycle arrest (G2/M phase) at mild concentrations (50 and 30 μg/mL) depending on the cell type and tumor origin. These results indicate that bracken fern extract is a potent source of anticancercompounds that could be utilized pharmaceutically.     

细胞周期对肿瘤坏死因子诱导Hela 细胞凋亡的影响

 目的　研究细胞周期对肿瘤坏死因子 ( TNF)诱导 Hela细胞凋亡的影响。方法　通过胸腺嘧啶核苷酸 ( Td R)阻断法阻滞 Hela细胞的细胞周期 ,以 MTT法、流式细胞术和荧光染色分析 Td R阻滞细胞和周期化的 Hela细胞对 TNF诱导凋亡的敏感性。结果　Td R阻滞细胞周期较周期化的 Hela细胞对 TNF诱导的凋亡的敏感性降低。结论　揭示 TNF诱导 Hela细胞凋亡与细胞周期有关.     

Anticancer Activity of Fucoidan via Apoptosis and Cell Cycle Arrest on Cholangiocarcinoma Cell

Objective: Many previous studies reported that fucoidan has antitumor activities. The objective of the present study was to determine the cytotoxic effects and related mechanisms of cell death induced by fucoidan extracted from Fucus vesiculosus on CL-6 cholangiocarcinoma cell. Methods: CL-6 and OUMS cells were treated with 0, 100, 200, and 300 μg/mL of fucoidan. MTT assay was used to determine cytotoxicity. Flow cytometry-based assay was used to examine the distribution of apoptosis and cell cycle. The changes in nuclear morphology were determined using Hoechst 33,342 staining. Mitochondrial membrane potential (ΔΨm) was evaluated using the JC-1 kit. The apoptotic, anti-apoptotic, and cell cycle-related proteins study were examined by Western blot analysis. Results: The relative viable cell number of treated CL-6 cells was decreased but no effect was observed in OUMS normal cells. Furthermore, treated cells were arrested in the G0/G1 phase with down-regulation of cyclin D1 and CDK4. Annexin V/PI staining with flow cytometry analysis suggested that fucoidan could induce apoptosis in CL-6 cells. Western blot study revealed the up-regulation of apoptotic markers including Bax, cleaved PARP, cleaved caspase-3, but down-regulation of anti-apoptotic markers,  cl-2. Moreover, fucoidan could induce nuclear fragmentation and chromatin condensation with alteration of ΔΨm.  Conclusion: Fucoidan exerts antitumor properties against CL-6 cholangiocarcinoma cells illustrated by the induction of apoptosis and cell cycle arrest.     

人肺腺癌多药抗药细胞系LC-3/CDDP细胞周期及DNA含量变化

应用流式细胞仪测定人肺腺癌多药抗药细胞系LC－3／CDDP之细胞周期、DNA指数，用3H-胸腺嘧啶核苷掺入法测定DNA合成动态，结果显示，LC－3／CDDP细胞系G2＋M峰较亲代细胞明显增高，G期细胞比例降低，S期、G2＋M期比例升高，DNA指数增加，DNA合成速率较亲代细胞显著增快。提示人肺腺癌多药抗药细胞系LC－3／CDDP对DNA损伤的修复功能增强。     

姜黄素对人舌鳞癌Tca8113细胞周期的影响

目的探讨不同浓度姜黄素对人舌鳞癌Tca8113细胞周期分布的影响。方法将Tca8113细胞培养于含有不同浓度姜黄素(0、20、40μmol/L)的RPM I-1640培养基中进行培养至规定时间终止培养,流式细胞仪分析细胞周期变化。结果随着姜黄素浓度的升高与作用时间的增加,其对细胞抑制作用明显增强,细胞周期中G0/G1期细胞比例逐渐增加,由46.20%上升至64.80%,S期细胞比例由53.10%下降至31.40%,不同浓度、不同时间对细胞G0/G1期的阻滞作用比较差异有统计学意义(P<0.05)。结论姜黄素能明显改变Tca8113的细胞周期分布,有明显G0/G1期阻滞作用,并有量-效、时-效关系。     

Relation between Nucleolar Size and Growth Characteristics in Small Cell Lung Cancer Cell Lines

Relationships among cytological features, doubling time, S-phase percentage, expression of myc- family oncogenes, DNA ploidy and biochemical properties were studied in thirteen small cell lung cancer cell lines. Six cell lines that grew slowly (average doubling time 99 h) and had lower S-phase percentages (average 32%) showed inconspicuous nncleoli (average area of 1.5 μm²), and the remaining seven cell lines that grew quickly (average doubling time 45 h) and had higher S-phase percentages (average 44%) showed large and prominent nncleoli (average area of 6.1 μm²). DNA index value obtained from flow cytometric DNA histograms showed that all cell lines except for H-69 cell line displayed aneuploidy. Ribbon-like cell arrangements were observed in the 7 cell lines that grew quickly, and in 1 cell line that grew slowly. Biochemically, six slow-growing cell lines and four fast-growing cell lines showed high levels of aromatic L-amino acid decarboxylase activity, while in the remaining three fast-growing cell lines its level was low. A high level of c-myc or N- myc oncogene expression was observed in all 7 cell lines that grew quickly, but not in any of the 6 cell lines that grew slowly. It appears that small cell lung cancer cell lines that grow quickly can be expected to have large nucleoli and ribbon-like cell arrangements and to express high levels of myc family oncogenes, and that nucleolar size is a good indicator for growth characteristics.     

Local Anaesthetics Modifying the Dermal Response of Irradiation: An experimental study

In a series of experiments in rabbits the dermal reaction, provoked by a single dose or intermittent doses of irradiation, was prevented or modified by topical or parenteral administration of local anaesthetics, compared to irradiated control animals. The topical application of a eutectic lidocaine/prilocaine cream, EMLA 5%, was found to be more effective than intravenously injected lidocaine (Xylocain 1%).     

GW843682X对鼻咽癌细胞周期和凋亡的影响

[目的]研究GW843682X对鼻咽癌5-8F细胞周期和凋亡的影响。[方法]培养鼻咽癌5-8F细胞,0、6.25、12.5、25、50、100、200和400nmol/L的GW843682X处理后,用CCK8试剂检测药物对细胞增殖的影响。分别以0、250,500,1000nmol/L的GW843682X处理5-8F细胞48h后,用PI单染流式细胞仪检测药物对5-8F细胞周期的影响。用Annexin V-FITC双染细胞后,经流式细胞仪检测细胞凋亡的变化。[结果]CCK8比色结果显示,GW843682X能抑制鼻咽癌5-8F细胞的增殖,当药物浓度大于50nmol/L时,细胞增殖显著受抑。细胞周期检测结果显示,与阴性对照组比较,GW843682X增加了G2/M期细胞阻滞,减少了G0/G1期细胞比例（P〈0.05）。细胞凋亡检测结果显示,与对照组相比,随着GW843682X浓度的增加,凋亡细胞所占比例逐渐增大,当药物浓度达到500nmol/L和1000nmol/L时,凋亡细胞所占比例显著增加（P〈0.05）。[结论]GW843682X能够显著抑制鼻咽癌5-8F细胞的增殖,可以诱导细胞阻滞于G2/M期,其诱导5-8F细胞凋亡呈一定的剂量依赖性。     

Mitogenic Signaling and the Relationship to Cell Cycle Regulation in Astrocytomas

The activity and regulation of a number of mitogenic signaling pathways is aberrant in astrocytomas, and this is thought to play a crucial role in the development of these tumors. The cascade of events leading to the formation and the progression from low-grade to high-grade astrocytomas is well characterized. These events include activating mutations, amplification, and overexpression of various growth factor receptors (e.g. epidermal growth factor receptor (EGFR), platelet derived growth factor receptor (PDGFR), c-Met), signaling intermediates (e.g. Ras and Protein kinase C (PKC)), and cell cycle regulatory molecules (e.g. mouse double minute-2 (Mdm2), cyclin-dependent kinase-4 (CDK4), and CDK6), that positively regulate proliferation and cell cycle progression. Inactivating mutations and deletions of signaling and cell cycle regulatory molecules that negatively regulate proliferation and cell cycle progression (e.g. p53, p16/INK4a, p14/ARF, p15/INK4b, retinoblastoma protein (Rb), and Phosphatase and tensin homologue deleted from chromosome 10 (PTEN)) also participate actively in the development of the transformed phenotype. Several mitogenic pathways are also stimulated via an autocrine loop, with astrocytoma cells expressing both the receptors and the respective cognate ligand. Due to the multitude of factors involved in astrocytoma pathogenesis, attempts to target a single pathway have not given satisfactory results. The simultaneous targeting of several pathways or the targeting of signaling intermediates, such as Ras or PKC, situated downstream of many growth factor receptor signaling pathways may show more efficacy in astrocytoma therapy. We will give an overview of how the combination of these aberrations drive astrocytoma cells into a relentless proliferation and how these signaling molecules may constitute relevant therapeutic targets.     

低剂量辐射对肿瘤细胞凋亡、细胞周期以及凋亡相关蛋白Bcl-2的影响

目的探讨低剂量辐射对小鼠移植肿瘤细胞的凋亡、细胞周期以及Bcl-2的影响。方法昆明种雄性小鼠左后肢腹股沟皮下接种S180肉瘤细胞,接种后7天γ射线全身照射75mGy,照射后24、48小时分别处死直接测量肿瘤大小变化,取肿瘤组织分别进行流式细胞仪分析凋亡、细胞周期以及免疫组化染色半定量分析凋亡相关蛋白Bcl-2表达的变化。结果与直接荷瘤组相比,低剂量照射组肿瘤生长缓慢(P<0.05),24小时后肿瘤细胞阻滞于G1期,Bcl-2蛋白表达下降,48小时后肿瘤细胞凋亡增加(P<0.001)。结论低剂量辐射可使机体肿瘤细胞阻滞于G1期并通过凋亡相关蛋白表达变化导致肿瘤细胞凋亡增加,明显提高机体抗肿瘤的作用,具有肿瘤治疗和辅助放化疗的实际临床意义。