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AnnexinV-FITC联合PI双染法和Ap02.7单抗法流式细胞仪（FCM）定量检测原代HUVEC和PC-细胞在0-10Gy的6MV-X射线照射后细胞周期和凋亡的变化。结果 照射后24h和48h两种细胞均出现明显G0/G1期减少和G2/M期增加，但2Gy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。     

原代培养人脐静脉内皮细胞电离辐射效应的初步研究

目的 :初步探讨人脐静脉内皮细胞 (HUVEC)原代培养的电离辐射效应。方法 :HUVEC经体外原代培养并用电镜及免疫组化法鉴定 ;形态学观察和流式细胞仪 (FCM )测定单次 6MV X射线照射 0～10Gy后 2 4和 4 8h细胞周期和凋亡 ;放免法和硝酸还原酶法分别测定内皮素 (ET 1)及一氧化氮 (NO)代谢产物NO-2 的含量。结果 :按本法原代培养的HUVEC生长良好 ,并证明是血管内皮细胞 ;FCM经 5和 10Gy照射后 2 4及 4 8h出现明显G0 G1期细胞比例减少 ,G2 M期增加及分泌ET 1减少 ,但无照射引起的细胞凋亡和NO分泌的变化。结论 :本方法原代培养的HUVEC经鉴定确为人血管内皮细胞 ,生长汇合后有一定的辐射抗拒性。     

原代培养人脐静脉内皮细胞电离辐射效应的初步研究

目的：初步探讨人脐静脉内皮细胞(HUVEC)原代培养的电离辐射效应。方法：HUVEC经体外原代培养并用电镜及免疫组化法鉴定；形态学观察和流式细胞仪(FCM)测定单次6MV-X射线照射0～10Gy后24和48h细胞周期和凋亡；放免法和硝酸还原酶法分别测定内皮素(ET-1)及一氧化氮(NO)代谢产物NO2^-的含量。结果：按本法原代培养的HUVEC生长良好，并证明是血管内皮细胞；FCM经5和10Gy照射后24及48h出现明显G0／G1期细胞比例减少，G2／M期增加及分泌ET-1减少，但无照射引起的细胞凋亡和NO分泌的变化。结论：本方法原代培养的HUVEC经鉴定确为人血管内皮细胞，生长汇合后有一定的辐射抗拒性。     

电离辐射对食管癌细胞周期及MDC1、53BP1蛋白表达的影响

目的 观察60Co γ射线照射后食管癌细胞周期、细胞凋亡及其相关蛋白表达的变化,为食管癌放射治疗、靶向治疗提供理论依据。方法 食管癌细胞株TE 13进行不同剂量（0、1、2、5、10、15Gy）照射后,应用流式细胞术分别检测照射后1、2、12、24和48h细胞周期和凋亡指数的变化;同时采用Western blot方法检测MDC1和53BP1蛋白表达情况。结果 TE 13细胞照射后12、24、48h,TE 13细胞的G0/G1期、G2/M期和S期的变化呈现明显剂量依赖性,1Gy和2Gy照射后12h,细胞G2/M期阻滞开始出现;5、10、15Gy照射后24h,细胞G2/M期阻滞最为明显,与对照组（0Gy组）相比,差异具有统计学意义（P<0.05）;15Gy照射后12h、24、48h,TE 13细胞的凋亡增加非常显著（P<0.01）;不同剂量照射后1、2、24h,TE 13细胞MDC1和53BP1蛋白表达未见明显变化（P>0.05）。结论 TE 13细胞经不同剂量放射线照射后,细胞周期出现明显的G2/M期阻滞,细胞凋亡指数明显增加,但对MDC1和53BP1蛋白表达未见明显影响。     

放射诱导的六株细胞系细胞周期和细胞凋亡变化的观察

目的:探讨放射诱导的6株细胞系细胞周期和细胞凋亡的变化特点.方法:正常肝细胞系HL-7702,肝癌细胞系HepG2和SMMC-7721,肺小细胞癌HCI-H460,肺腺癌A549和宫颈癌细胞系Hela常规培养48 h后接受4 Gy X射线照射;收获受照前(0h)和受照后6、12、24、36和48h的细胞,采用流式细胞术(FCM)检测各细胞系细胞凋亡和细胞周期.结果:在4 Gy X线照射前,SMMC-7721和HCI-H460细胞凋亡率明显高于其他4株细胞系,两者差异有统计学意义(t=20.98,P<0.005);在照射后12 h,与照射前相比6株细胞系细胞凋亡率均有显著增加(t=5.27,P<0.05),SMMC-7721、HCI-H460和A549同时伴有S期和G2～M期细胞比率的降低;在照射后36h HCI-H460出现第2个细胞凋亡峰,伴有极低比例的S期和G2～M期细胞;HepG2在照射后12h、HL-7702和Hela在照射后24h均有明显的G2/M期阻滞.结论:4 Gy X线诱导的细胞凋亡主要发生在射线照射后12～36h,6株细胞系可能均发生了"有丝分裂前凋亡";每株细胞还呈现了不同的细胞凋亡和细胞周期变化特点,具有组织细胞特异性.     

电离辐射对胃癌细胞增殖和周期的影响

目的：研究电离辐射对体外胃腺癌细胞增殖、凋亡及周期的影响。方法：~（60）Coγ射线单次照射胃腺癌BGC-823细胞,照射剂量分别为0、2、4 Gy,利用MTT和克隆形成率实验检测各剂量组BGC-823的增殖能力;同时利用Annexin-V/PI双染法检测各剂量组BGC-823细胞的凋亡;用PI单染测定各剂量组BGC-823的细胞周期。结果：与0 Gy组相比,2、4Gy 60Coγ射线照射可显著抑制胃腺癌BGC-823细胞的增殖（P〈0.05）,诱导BGC-823细胞在照射后依次出现S期和G2/M期阻滞。4Gy 60Coγ射线照射后48h,凋亡细胞比例显著高于对照组（P〈0.05）。结论：60Coγ射线照射可抑制胃腺癌细胞BGC-823增殖、诱导胃癌细胞出现周期阻滞和细胞凋亡。     

抑制ATM表达致鼻咽癌细胞CNE1辐射增敏的细胞周期阻滞研究

背景与目的:细胞周期调控是决定细胞辐射敏感性的决定性因素之一。共济失调毛细血管扩张症突变基因(ataxia-telangiectasia mutant,ATM)功能与细胞DNA损伤修复、细胞周期检查点调控密切相关。我们前期研究通过反义RNA抑制ATM基因表达可增加鼻咽癌细胞系CNE1辐射敏感性,本研究拟探讨其辐射增敏的细胞周期阻滞调控机制。方法:ATM反义组细胞CNE1/pDOR-atm及对照组细胞CNE1/pDOR经2Gy、5GyX线照射后不同时间点(1h、4h、8h、24h、48h)收获,应用流式细胞仪(flowcytometer,FCM)检测各细胞周期百分比及凋亡率。结果:两组细胞X线照射后均未出现明显G1期阻滞和细胞凋亡,但分别在照射后1h、4h、8h出现明显S期阻滞,24h、48h出现明显G2期阻滞,其中反义组S期细胞百分率总均数水平低于对照组(P<0.05),而G2/M期细胞百分率总均数水平高于对照组(P<0.05)。结论:反义RNA抑制ATM表达致CNE1辐射增敏的细胞周期调控机制可能与减少S期细胞比例,增加G2/M期细胞比例有关,与G1期阻滞和细胞凋亡的调控无关。     

食管癌细胞照射后细胞周期及相关蛋白表达的变化

目的：探讨食管癌细胞照射后细胞周期、细胞凋亡及其相关蛋白表达的变化。方法：食管癌细胞株TE-1和TE-13照射2、5、10、15Gy后，应用流武细胞仪分别检测照射后6、24和48h细胞周期和凋亡指数变化、Western blot检测细胞周期相关蛋白的表达。结果：2、5、10、15Gy照射0～48h，TE-1和TE-13细胞均出现明显剂量依赖性的G2／M期阻滞和解除变化；5～15Gy照射后48h，TE-13细胞在G2／M期阻滞逐渐解除时伴随着细胞凋亡的明显增加，而TE-1细胞凋亡不增加。2株细胞胞浆CHK2-p68磷酸化水平均呈随照射后时间延长而出现时相性变化，但与照射剂量无关；而CHK1、CHK2、CHK1-p345和CDK1蛋白表达均无明显变化。15Gy照射后24h，TE-13细胞胞浆中eyelin B1表达下降而TE1细胞中无明显变化。结论：病理不同分化的食管癌细胞照射后细胞周期、细胞凋亡以及细胞周期相关蛋白表达变化不尽相同。     

shRNA转染对食管癌细胞TE13中CHK1和CHK2表达以及照射后G2/M期阻滞的影响

背景与目的:肿瘤细胞照射后常表现为细胞周期的变化,本研究采用细胞周期监测点激酶CHK1和CHK2基因的短发卡状RNA(shRNA)转染食管癌细胞,观察对其蛋白表达以及60Co γ射线照射后细胞周期的影响.方法:设计合成并构建质粒连接的CHK1和CHK2 shRNA,分别提取质粒DNA并采用脂质体转染TE13细胞并传代;采用Western blot、RT-PCR和流式细胞仪分别检测CHK1和CHK2蛋白和muRNA表达、以及5 Gy 60Co γ射线照射后细胞周期变化,克隆形成实验检测5 Gy γ射线照射后细胞存活率.结果:采用CHK1和CHK2 shRNA转染TE13细胞后,其mRNA和蛋白表达均明显降低.单纯5 Gy γ射线照射后24 h,TE13细胞G2/M期比例由未照射组的32.17%增至6147%;shRNA转染的TE13细胞在5 Gy γ射线照射后24 h,C2/M期比例由单纯照射组的61 47%降至28.13%(CHK1)和42.80%(CHK2),P＜0.05.5 Gy γ射线、CHK1 shRNA力5 Gy γ射线、以及CHK2 shRNA力5 Gy γ射线照射后,细胞存活率分别为27.0%、13.0%和21.0%.shRNA转染的子一代TE13细胞在转染后120 h,对CHK1和CHK2蛋白表达的抑制作用已基本消失:转染120 h后以5 Gy γ射线照射24 h,CHK1或CHK2 shRNA转染组G2/M期比例高于单纯照射组,P＜0.05;至转染后144 h和5 Gy γ射线照射后48 h,转染组与单纯照射组比较G2/M期比例无明显差别,P＞0.05.结论:采用质粒连接的人CHK1和CHK2 shRNA转染TE13细胞后,可以明显抑制其mRNA和蛋白表达并消除照射后G2/M期阻滞,增加放射敏感性;提示TE13细胞γ射线照射后G2/M期检测点可能受CHK1和CHK2激酶双重调节,但以CHK1为主.     

6MV-X射线对肝癌细胞凋亡及周期分布的影响

目的:研究人肝癌细胞接受不同剂量或时间的6MV-X线照射后,对细胞凋亡和周期进程的影响。方法:用流式细胞术检测6MV-X线照射4Gy后不同时间以及不同剂量6MV-X线照射后24h HepG2和PLC/PRF/5两种细胞的细胞凋亡和周期分布状况。结果:4Gy 6MV-X线照射后24h,HepG2细胞凋亡率高于PLC/PRF/5细胞,分别为(7.61±0.77)%和(5.63±0.87)%(P<0.05),且随时间和剂量增加,差异越显著;HepG2细胞受4Gy照射后12h,G0/G1期比例下降,为(40.56±1.59)%,后逐渐上升,G2/M期比例增高,为(13.28±1.02)%,随后逐渐下降;2-6Gy照射24h后,G0/G1期比例逐渐上升,G2/M期比例逐渐下降;PLC/PRF/5细胞G2/M期比例在照射后24h阻滞最明显(22.11±1.48)%,后逐渐降低,随照射剂量增加而增大。结论:2-6Gy 6MV-X线照射可诱导HepG2与PLC/PRF/5细胞凋亡,并改变周期进程,HepG2细胞发生G1和G2期阻滞,PLC/PRF/5发生G2期阻滞。     

Pure seminoma: A review and update

Background

Prostate cancer (PrCa) displays resistance to radiotherapy (RT) and requires radiotherapy dose escalation which is associated with greater toxicity. This highlights a need to develop radiation sensitizers to improve the efficacy of RT in PrCa. Ionizing radiation (IR) stimulates pathways of IR-resistance and survival mediated by the protein kinase Akt but it also activates the metabolic energy sensor and tumor suppressor AMP-Activated Protein Kinase (AMPK). Here, we examined the effects of the polyphenol resveratrol (RSV) on the IR-induced inhibition of cell survival, modulation of cell cycle and molecular responses in PrCa cells.

Methods

Androgen-insensitive (PC3), sensitive (22RV1) PrCa and PNT1A normal prostate epithelial cells were treated with RSV alone (2.5-10 μM) or in combination with IR (2-8 Gy). Clonogenic assays, cell cycle analysis, microscopy and immunoblotting were performed to assess survival, cell cycle progression and molecular responses.

Results

RSV (2.5-5 μM) inhibited clonogenic survival of PC3 and 22RV1 cells but not of normal prostate PNT1A cells. RSV specifically sensitized PrCa cells to IR, induced cell cycle arrest at G1-S phase and enhanced IR-induced nuclear aberrations and apoptosis. RSV enhanced IR-induced expression of DNA damage (γH2Ax) and apoptosis (cleaved-caspase 3) markers as well as of the cell cycle regulators p53, p21^cip1 and p27^kip1. RSV enhanced IR-activation of ATM and AMPK but inhibited basal and IR-induced phosphorylation of Akt.

Conclusions

Our results suggest that RSV arrests cell cycle, promotes apoptosis and sensitizes PrCa cells to IR likely through a desirable dual action to activate the ATM-AMPK-p53-p21^cip1/p27^kip1 and inhibit the Akt signalling pathways.     

An investigation of fludarabine as a potential radiation sensitizer of human prostate cancer cells in vitro

Aim: Patient relapse following radiotherapy for prostate cancer is of major concern to oncologists. As chemotherapeutic agents have shown promise as radiation sensitizers, we investigated the use of fludarabine monophosphate as a radiation enhancement agent in human LNCaP‐LN3, PC3 and LNCaP prostate carcinoma cell lines with different sensitivities to fludarabine and ionizing radiation. Methods: Cells were treated with non‐cytotoxic doses of fludarabine for 16 h pre‐irradiation or 5 days post‐irradiation; survival fractions were determined by clonogenic assay. Cell cycling was also assessed. Results: LNCaP‐LN3 cells incubated with 1 μmol/L fludarabine for 5 days post‐irradiation were slightly sensitized (1.18 times, P = 0.029), whilst 16 h pre‐incubation had no effect on the radiation response. PC3 cells incubated with 10 μmol/L fludarabine for 16 h pre‐irradiation were sensitized to ionizing radiation (1.61 times, P < 0.0001), but treatment for 5 days post‐irradiation with fludarabine had no effect on their radiosensitivity. Neither fludarabine incubation had any effect on the sensitivity of LNCaP cells to ionizing radiation. A characterization of the cell cycle following 16 h exposure to fludarabine demonstrated that enhanced radiosensitivity of PC3 cells is independent of cell cycle. Conclusion: PC3, but not LN3 or LNCaP cells, were sensitized to ionizing radiation by pre‐incubation with 10 μmol/L fludarabine for 16 h (1.61 times, P < 0.0001) but not by post‐irradiation exposure to the drug. The enhanced radiosensitivity of PC3 cells is independent of cell cycle. Further studies are required to elucidate the mechanism of fludarabine mediated sensitization in these cells.     

叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的机制

目的 探究叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的作用机制,为前列腺癌预防及治疗提供新的理论依据。方法 不同浓度叶黄素作用于PC3细胞,CCK8法检测细胞增殖情况;流式细胞仪检测细胞周期分布和凋亡变化;细胞划痕和Transwell实验观察细胞迁移和侵袭能力;RT-PCR和Western blot技术检测细胞中Bax、Bcl-2的mRNA水平和蛋白表达。结果 叶黄素显著抑制PC3细胞的增殖,并呈时间和浓度依赖性。叶黄素可以将细胞生长阻滞在G0/G1期,抑制细胞迁移和侵袭;还可促进细胞凋亡,使Bcl-2表达下降,Bax表达上升。叶黄素可在转录水平上下调Bcl-2 mRNA和上调BaxmRNA。结论 叶黄素抑制PC3细胞增殖并促进其凋亡,其机制可能与阻滞细胞周期、抑制细胞迁移、侵袭以及调节凋亡相关基因和蛋白表达有关。     

Modulation of radiation response and tumor-induced angiogenesis after epidermal growth factor receptor inhibition by ZD1839 (Iressa)

ZD1839 ("Iressa") is an orally-active, selective epidermal growth factor receptor-tyrosinekinase inhibitor. We evaluated the antitumor activity of ZD1839 in combination with radiation in human squamous cell carcinomas (SCCs) of the head and neck. ZD1839 produced a dose-dependent inhibition of cellular proliferation in human SCCs grown in culture. Flow cytometry analysis of cell cycle progression confirmed the accumulation of cells in G(1) phase after exposure to ZD1839. Clonogenic analysis demonstrated that treatment of SCCs with ZD1839 reduced cell survival after radiation exposure. Flow cytometric analysis further demonstrated that treatment of SCCs with ZD1839 amplified radiation-induced apoptosis. Tumor xenograft studies confirmed that oral administration of ZD1839, or focal radiation, resulted in partial and transient tumor regression in both SCC-1 and SCC-6 xenografts. In contrast, profound tumor regression and regrowth delay was observed in mice treated with the combination of ZD1839 and radiation. To examine antiangiogenic effects, we studied the impact of ZD1839 on human umbilical vascular endothelial cells (HUVECs). In the presence of reconstituted Matrigel matrix, HUVECs established a capillary-like network structure (tube formation). Treatment with ZD1839 reduced the cell-to-cell interaction of HUVECs, resulting in disruption of tube formation. The effect of ZD1839 was further examined using an in vivo tumor xenograft model of angiogenesis (Matrigel plug) in athymic mice. Systemic treatment with ZD1839 significantly inhibited tumor-induced neovascularization across the Matrigel plug. Taken together, these results suggest that the antitumor activity of ZD1839 in combination with radiation appears to derive from not only proliferative growth inhibition (with associated cell cycle arrest and enhancement of radiation-induced apoptosis) but also from inhibition of tumor angiogenesis.     

培美曲塞对PC9肺腺癌细胞株的放射增敏作用

目的 培美曲塞是治疗非鳞癌非小细胞肺癌(non-small cell lung cancer,NSCLC)的常用药物,其对表皮生长因子受体(pithelial growth factor receptor,EGFR)敏感突变的肺腺癌是否具有放射增敏作用尚未明确.本课题研究培美曲塞在体外对EGFR 19外显子突变的人肺腺癌细胞株PC9的放射增敏作用,并初步探讨其作用机制.方法 以PC9细胞作为研究对象,采用MTT法检测培美曲塞的20%抑制浓度(20% inhibition concentration,IC20),将PC9细胞分为对照组、单独照射组、培美曲塞单药组和培美曲塞+照射组4组;采用流式细胞术检测培美曲塞联合或不联合照射对PC9细胞的凋亡率及细胞周期的影响;克隆形成实验检测培美曲塞对PC9细胞的放射效应,计算存活分数,拟合存活曲线;蛋白质印迹法检测CDC20蛋白在各组的表达.结果 MTT结果显示,PC9细胞的增殖抑制与培美曲塞呈时间-剂量依赖性,取48 h的IC20(0.084 μmol/L)的培美曲塞作为实验浓度.流式细胞术结果显示,培美曲塞单药组和单独照射组均可增加凋亡率,分别为(7.17±1.14)%和(10.78±1.52)%,而培美曲塞+照射组具有协同增效作用,凋亡率达(29.23±1.33)%,F=227.57,P<0.001;细胞周期结果显示,对照组G2/M期比例为(0.79±0.63)%,培美曲塞单药组为(0.79±0.47)%,单独照射组为(18.21±0.72)%,培美曲塞+照射组为(25.09±1.04)%,提示培美曲塞使细胞阻滞在S期,与放射线联合作用后,S期细胞比例减少,G2/M期的比例明显增多,差异有统计学意义,F=276.85,P<0.001.克隆形成实验提示,培美曲塞具有较好的放射增敏作用,其放射增敏比(sensitization enhancement ratio,SER)为1.41.培美曲塞联合照射能增加细胞周期相关蛋白CDC20的表达,F=282.12,P<0.001.结论 培美曲塞可提高EGFR 19外显子突变的PC9肺腺癌细胞的放射敏感性,其机制可能与照射引起CDC20的增加致对放射敏感的G2/M期阻滞,而照射耐受的S期比例减少有关.     

BAY 11-7082对人前列腺癌PC-3细胞增殖和凋亡的影响

目的:探讨BAY 11-7082对人前列腺癌PC-3细胞增殖和凋亡的影响.方法:选择PC-3细胞分别加入不同浓度(2.5μmol/L、5μmol/L)的Bay 11-7082培养2h(实验1组与实验2组),同时选择空白对照组,检测三组细胞增殖、凋亡与细胞周期变化情况.结果:实验1组与实验2组的细胞存活率分别为(65.14±13.26)%和(55.81±14.55)%,明显低于空白对照组(85.45±12.33)%(P<0.05).空白对照组、实验1组与实验2组的细胞凋亡率分别为(0.56±0.11)%、(10.12±2.37)%和(17.23±2.46)%,对比差异都有统计学意义(P<0.05).实验组的G 0/G1期细胞数目较对照组明显增加(P<0.05),同时实验组的S、G 2/M期细胞数目较对照组明显减少(P<0.05),实验1组与实验2组之间对比差异也有统计学意义(P<0.05).结论:BAY 11-7082能明显抑制人前列腺癌PC-3细胞的增殖,诱导细胞发生凋亡,其部分机制可能是通过调节细胞周期实现的.     

Survival and cell cycle kinetics of human prostate cancer cell lines after single- and multifraction exposures to ionizing radiation

PURPOSE: Fractionated radiation therapy is frequently used to treat prostate cancer with an underlying assumption that each daily dose of ionizing radiation (IR) results in equal cell killing. We used three human prostate cancer cell lines to evaluate how survival after a single 2-Gy dose may predict responses after daily repeated 2-Gy exposures. METHODS AND MATERIALS: LNCaP, CWR22R, and PC3 cells were used in these studies. Survival after IR exposures was assessed using clonogenic assays and cell cycle responses were determined by flow cytometry. RESULTS: The experimentally determined multifraction survival differed significantly from that predicted from their single-dose SF2. LNCaP and CWR22R cells showed lower than predicted survivals; PC3 cells exhibited greater than predicted survival. Daily IR exposures resulted in changes in the cell cycle distributions beyond those caused by a single exposure to IR. CONCLUSIONS: Our results show that in these prostate cancer cells: (1) survival after a clinically relevant dose of IR does not predict survival after multifraction IR, (2) cell cycle responses after a single 2 Gy dose can differ from those that occur when cells receive daily 2 Gy doses, and (3) some cell cycle changes that result from fractionated IR may predict their ultimate survival responses from such treatment.