全反式维甲酸通过DOK1/PPARγ信号通路抑制人乳腺癌细胞MCF-7的增殖

目的:探讨全反式维甲酸(ATRA)对人乳腺癌细胞MCF-7增殖的影响及可能机制。方法:MCF-7细胞培养于含10%胎牛血清、1%青霉素/链霉素的DMEM培养液,蛋白免疫印迹检测蛋白质的表达,MTT法和溴脱氧尿嘧啶核苷(Brd U)掺入法测定细胞增殖,TUNEL法测定细胞凋亡,携带目标基因shRNA的慢病毒用于沉默目标基因,过氧化物酶体增殖物激活受体γ(PPARγ)的活性采用商品化的试剂盒测定。结果:ATRA处理可抑制MCF-7细胞的增殖,促进其凋亡;同时,ATRA以时间依赖方式刺激停靠蛋白1(DOK1)的表达。沉默DOK1可降低ATRA对MCF-7细胞增殖和凋亡的影响。此外,DOK1基因沉默可抑制PPARγ的表达和活性。而PPARγ选择性抑制剂GW9662可减轻ATRA对MCF-7细胞增殖的抑制和对细胞凋亡的促进作用。结论:ATRA通过抑制细胞增殖、促进细胞凋亡而抑制MCF-7细胞的生存,这一作用经DOK1激活的PPARγ介导。     

龙血素A对体外培养人乳腺癌MCF-7细胞生长和雌激素受体表达的影响

目的:观察龙血素A对体外培养人乳腺癌MCF-7细胞生长和雌激素受体(ER)表达的影响。方法:采用龙血素A与MCF-7细胞体外共培养(药物组)干预手段,运用四甲基偶氮唑蓝(MTT)检测细胞的增殖情况;Hoechst33258染色检测细胞凋亡率;免疫荧光和免疫印迹检测ERα和ERβ蛋白的表达。结果:与对照组相比,药物组细胞增殖受到明显抑制,细胞凋亡率明显增加;免疫荧光和免疫印迹检测结果显示药物组ERα表达显著减少,而ERβ的表达显著增加。结论:龙血素A对体外培养人乳腺癌MCF-7细胞具有明显抑制生长和促进凋亡作用,其机制可能与龙血素A能下调ERα表达和上调ERβ表达有关。     

EPCR通过活化PAR-1促进人乳腺癌MCF-7细胞增殖及迁移

目的探讨内皮细胞蛋白C受体(endothelial protein C receptor,EPCR)对乳腺癌增殖、迁移的影响及机制研究。方法采用siRNA技术降低人乳腺癌MCF-7细胞中EPCR的表达;添加抗PAR-1抗体阻断PAR-1作用,然后采用CCK-8检测细胞的增殖能力、Transwell检测迁移能力、Cell-ELISA检测EPCR对PAR-1活性的影响。结果 EPCR干扰后,与空白对照组及无关序列组相比,EPCR干扰组MCF-7细胞的增殖及迁移能力均明显降低(P0.05)。抗PAR-1抗体处理后,与空白对照组相比,PAR-1抗体处理组细胞的增殖迁移能力均明显降低(P0.05)。并且Cell-ELISA结果显示EPCR干扰组未裂解活化的PAR-1抗体结合率明显升高(P0.05)。结论 EPCR可以通过活化PAR-1促进人乳腺癌MCF-7细胞增殖迁移。     

Let-7维持乳腺癌干细胞的特性及机制的研究

目的:研究let-7在乳腺癌干细胞中的表达,探索let-7影响乳腺癌干细胞的特性及机制。方法:采用SP分选法,分选乳腺癌细胞系MCF-7中的SP及NSP细胞亚群;运用实时定量PCR法检测MCF-7细胞系中SP、NSP亚群let-7a/b/c的表达;通过Western blot法检测Ras、ERK蛋白在MCF-7细胞系中SP、NSP亚群中的表达,探索let-7维持乳腺癌干细胞特性的机制。结果:SP侧群细胞占MCF-7细胞的3.3%,加入维拉帕米抑制干细胞外排荧光染料Hoechst33342的功能后,SP侧群细胞占乳腺癌MCF-7细胞的比例下降至0.4%。Let-7miRNA在SP细胞中的表达低于NSP细胞,其中let-7b/c在SP及NSP亚群中表达差异最大;p-Ras、p-ERK在SP细胞中的表达高于NSP细胞,t-Ras及t-ERK的表达无明显差异。结论:SP法是一种可有效分离干细胞的方法,乳腺癌细胞系MCF-7中存在肿瘤干细胞亚群;let-7在乳腺癌干细胞中的表达低于普通肿瘤细胞,而p-Ras、p-ERK在乳腺癌干细胞中的表达高于普通肿瘤细胞,let-7的低表达失去了对Ras mRNA的抑制,使Ras信号转导通路激活,进而磷酸化的p-Ras和p-ERK表达升高,维持乳腺癌干细胞的功能。     

山奈酚增强阿霉素在乳腺癌模型中的抗癌作用*

目的：评价山奈酚（KPL）和阿霉素（DOX）在乳腺癌小鼠模型中的联合作用以及预防后者引起的心脏毒性。 方法：采用MTT法检测KPL+DOX（0.1 μmol/L）对乳腺上皮细胞MCF10A、乳腺癌来源的细胞系MCF-7 细胞株 的细胞毒性, 免疫印迹检测MCF-7 细胞中组蛋白去乙酰化酶（HDAC）、DNA 甲基化酶（DNMT）、雌激素受体α （ERα）、caspase-3 蛋白表达情况。采用原位乳腺癌模型评估KPL对DOX 诱导的肿瘤消退和心脏毒性的影响,将 裸鼠根据肿瘤体积分为溶媒处理组、DOX 组、KPL组及DOX+KPL 联合处理组,借助超声心动图监测各组小鼠 的心脏功能,免疫组织化学分析肿瘤组织的病理变化、caspase-3 及聚腺苷二磷酸核糖聚合酶（PARP）的表达情况。 结果：MTT分析表明,KPL+DOX 对MCF10A和MCF-7 细胞的抑制作用高于DOX。与DOX 组相比,KPL+DOX 显著抑制了MCF-7 细胞中HDAC、DNMT 活性,并降低ERα 水平。动物实验表明,KPL+DOX 对MCF-7 肿瘤生 长的抑制作用大于DOX。超声心动图检测显示,KPL+DOX 联合处理可以改善由DOX 引起的心脏毒性、显著降 低了DOX 诱导的MDA 形成和TNF-α、IL-6 炎性细胞因子水平,同时提高了GSH 水平。免疫组织化学分析显示, KPL+DOX 组表现出明显的核凝聚和碎裂,并且caspase-3 和PARP表达水平显著高于其他3 组。结论：KPL作为 一种常见且安全的膳食补充剂,可增强DOX 在癌症治疗中的抗癌活性,同时减少DOX 相关的心脏毒性。     

光动力疗法对人乳腺癌MCF-7细胞增殖凋亡的影响

目的 研究光动力疗法（PDT）对人乳腺癌MCF-7细胞增殖的影响和诱导凋亡的作用.方法 癌光啉（PSD-007）与细胞共同孵育2h后,以不同能量635 nm激光照射,通过噻唑蓝（MTT）比色法测定PDT后不同时间（0.5、1、3、6、12、24h）细胞的光密度（0D）值及存活率.DAPI染色观察PDT后不同时间细胞凋亡中细胞核形态学的改变.Annexin-V/PI双染法结合流式细胞术分析细胞凋亡率的变化.结果 PDT对MCF-7细胞的增殖有抑制作用,且随着PDT光照能量的提高而增强,PDT作用后细胞存活率随时间延长而逐渐降低.细胞形态学观察结果表明,MCF-7细胞呈典型的凋亡形态特征.Annexin-V/PI双染也证实PDT可以诱导细胞凋亡,且凋亡率随PDT作用后时间的延长而升高.结论 PDT能显著抑制MCF-7细胞增殖,诱导细胞凋亡,且其诱导肿瘤细胞的凋亡是一渐进性的过程,具有光照剂量和时间效应关系.     

锌转运体ZIP10过表达对乳腺癌细胞侵袭能力的影响

目的:将ZIP10基因真核表达载体转染乳腺癌细胞MDA-MB-231和MCF-7细胞,研究ZIP10过表达对乳腺癌细胞侵袭能力的影响.方法:经双酶切后凝胶电泳鉴定ZIP10基因表达载体pEGFP-N1-ZIP10,利用脂质体转染法将pEGFP-N1-ZIP10及其相应空载体分别转染乳腺癌细胞MDA-MB-231(ER-)及MCF-7(ER+).RT-PCR检测乳腺癌细胞中MMP-2、MMP-9的mRNA水平,Western blot技术检测细胞中ZIP10蛋白质的表达水平,MTT法观察转染pEGFP-N1-ZIP10前后乳腺癌细胞增殖活性,Transwell实验观察转染pEGFP-N1-ZIP10前后乳腺癌细胞侵袭能力的改变.结果:乳腺癌MCF-7和MDA-MB-231细胞瞬时转染成功后,MMP-2、MMP-9的mRNA 水平没有显著差异,MTT检测结果显示,pEGFP-N1-ZIP10转染乳腺癌细胞后对其增殖活性没有明显影响;Transwell肿瘤细胞侵袭实验显示,ZIP10过表达可显著增加乳腺癌细胞的侵袭能力.结论:ZIP10真核表达载体转染乳腺癌细胞系MCF-7和MDA-MB-231使ZIP10过表达,对细胞增殖活性没有明显影响,但可明显增加肿瘤细胞的侵袭能力.     

阿魏酸通过雌激素受体α调控人乳腺癌细胞系的增殖、迁移及侵袭

目的观察阿魏酸是否可调控人乳腺癌细胞系MCF-7长非编码RNA(lncRNAs)的表达水平及对细胞增殖、迁移及侵袭的影响。方法用0,1、2. 5、5、7. 5或10 mmol/L阿魏酸处理24 h后,CCK-8法检测细胞活力(n=3);软琼脂成瘤实验检测细胞体外成瘤能力; 0或2. 5 mmol/L阿魏酸处理24 h后,划痕实验及Transwell穿膜实验检测细胞增殖、迁移及侵袭能力(n=3);基因干扰和过表达技术检测雌激素受体α(ERα)是否参与阿魏酸对乳腺癌细胞的调控;反转录-实时荧光定量PCR(RT-qPCR)检测MALAT-1 mRNA表达。结果相比于对照组,阿魏酸呈浓度依赖性增加MCF-7细胞活力、增殖、成瘤、迁移和侵袭能力(P0. 05)。干扰ERα减弱阿魏酸对MCF-7细胞生理过程的调控;过表达ERα增强阿魏酸对MB231细胞的调控。同时发现阿魏酸通过ERα调控MALAT-1的表达。结论阿魏酸通过MCF-7中ERα的介导,调控了MALAT-1的表达与乳腺癌细胞的增殖、迁移及侵袭。     

钙激活中性蛋白酶介导雌激素增强MCF-7乳腺癌细胞的存活力

目的 探讨雌激素(E2)对MCF-7乳腺癌细胞钙激活中性蛋白酶1(CANP-1)基因表达和CANP蛋白酶活性的影响、以及CANP活性在E2增强细胞存活力中的作用.方法 以MCF-7乳腺癌细胞为研究模型、采用RT-PCR法检测mRNA表达、蛋白印迹法观察CANP特异性底物FAK蛋白剪切、血清饥饿诱导细胞死亡、锥虫蓝染色及细胞计数法检测细胞存活力.结果 E2(10 nmoL/L)可明显刺激乳腺癌细胞CANP-1基因表达上调,CANP抑制剂则可显著抑制E2诱导CANP-1基因上调;在无血清培养条件下,E2激活CANP活性及增加细胞存活力(14.3±4.9％,P＜0.05),而CANP抑制剂可显著抑制E2诱导CANP激活以及细胞存活力增强(19.2±3.9％,P＜0.05).结论 E2刺激MCF-7乳腺癌细胞CANP-1基因表达上调并增强CANP活性,后者可能参与介导血清饥饿时E2增强MCF-7细胞的存活力.     

负载乳腺癌细胞冻融抗原的DC对CTL体外特异性杀伤活性的影响

目的：研究乳腺癌患者腋下淋巴结单个核细胞来源的DC,经自体肿瘤细胞冻融抗原刺激后,对CTL体外特异性杀伤活性的影响。方法：以细胞因子分别诱导、培养乳腺癌腋下淋巴结单个核细胞中的DC及TDLNC,用自体癌细胞冻融抗原刺激DC,并和TDLNC共培养,诱导成为肿瘤抗原特异性CTL;检测特异性CTL对自体乳腺癌细胞及MCF-7细胞的体外杀伤活性。结果：DC-Ag-TDLNC、DC-TDLNC和TDLNC对自体乳腺癌细胞的杀伤率分别为67.64%、31.25%和26.36%,P〈0.001;三种TDLNC细胞对MCF-7细胞的杀伤率无明显差异（P〉0.05）。结论：乳腺癌患者腋下引流淋巴结中的单个核细胞在细胞因子的诱导、活化及自体肿瘤抗原刺激下,可分化为成熟DC,DC可促进TDLNC增殖、分化为特异性CTL,后者对自体肿瘤细胞有较高的杀伤活性。     

新型卟啉类光敏剂光动力治疗肝癌的体外实验研究

目的 探讨一种新型卟啉类光敏药物对人肝癌HepG2细胞的光动力学治疗（PDT）作用及其机制.方法 实验分为4组：阴性对照组,PDT组,药物组及药物＋PDT组.采用Bleaching法研究光敏药物的光稳定性;MTT法检测药物对HepG2细胞的PDT杀伤作用;荧光分光光度计检测光敏药物的细胞吸收量;激光共聚焦显微镜检测药物在癌细胞内定位;Hoechst 333342染色检测PDT后HepG2细胞死亡方式.结果 药物对光照比较稳定;单纯光照及单纯光敏药物自身均对HepG2细胞生长无任何影响（P＞0.05）,但药物孵育后行激光照射对HepG2细胞有强烈的PDT杀伤作用（P＜0.05）,IC50值为1.21 μmol/;细胞的药物吸收量呈显著的浓度依赖性,浓度至12.5 μmol/L时吸收量达到饱和;光敏药物分布于HepG2细胞溶酶体内;PDT后HepG2细胞死亡方式主要为凋亡.结论 新型光敏药物能够杀伤人肝癌HepG2细胞,其方式主要通过损伤溶酶体启动继发性的细胞凋亡实现的.     

中晚期食管癌光动力治疗联合化疗的回顾性研究

目的比较中晚期食管癌的单纯光动力治疗与光动力＋化疗联合治疗的短期疗效，探讨中晚期食管癌光动力＋化疗的治疗模式的优势。方法回顾性分析我院自2002年至2005年期间光动力治疗及光动力＋化疗治疗的食管癌患者60例（Ⅲ～Ⅳ期），其中单纯光动力治疗27例，光动力＋化疗治疗33例。光动力治疗使用光敏剂Photofrin 2mg／kg，48h后内镜引导下使用波长为630nm的激光照射，综合治疗组化疗方案为5-FU＋DDP，动力治疗后1周开始化疗，共化疗4周期。结果60例病人随访时间全部满2年，综合治疗组和单纯光动力治疗组症状缓解率分别为85．2％、93．9％，内镜评价有效率分别为85．2％、90．9％，无明显差异；2年生存率分别为54．5％、29．6％，综合治疗组中位生存期明显延长（Ⅲ期为22m、13m；Ⅳ期为7m、5m），差异有统计学意义（P=0．046）。结论光动力＋化疗治疗中晚期食管癌优于单纯光动力治疗，短期疗效相当，2年生存期有优势。     

Haematoporphyrin Based Photodynamic Therapy Combined with Hyperthermia Provided Effective Therapeutic Vaccine Effect against Colon Cancer Growth in Mice

Photodynamic therapy (PDT) has become an attractive option used in tumor treatment via its direct tumoricidal activities or its immune-boosting activities. On the other hand, heat shock protein 70 has been found to be largely associated with the establishment of anti-tumor activities offered by hyperthermia treated tumor cells. In the present study, we found that injection of tumor-bearing mice with colon cancer cell line CT-26 treated with haematoporphyrin based photodynamic therapy (hematoporphyrin monomethyl ether based PDT, HMME-PDT) together with hyperthermia demonstrated the most effective therapeutic effects against tumor growth, followed by cells treated by hyperthermia alone. CT-26 cells treated only with HMME-PDT failed to provide any therapeutic effects, although significant cell death was induced by HMME-PDT. Compared to hyperthermia treatment, HMME-PDT induced more efficient surface localization of HSP70 on CT-26 cells which correlated with efficient activation of cytolytic CD8 T cells and with effective anti-tumor responses. Thus, our study demonstrated that the surface expression of HSP70 may play a more important role than the total expression or release of this molecule in the activation of immune responses. And our study offered a novel modified PDT approach to the treatment of tumor cells intrinsically low on HSP70 expression.     

Photodynamic therapy with recombinant adenovirus AdmIL-12 enhances anti-tumour therapy efficacy in human papillomavirus 16 (E6/E7) infected tumour model

Immunotherapy with photodynamic therapy (PDT) offers great promise as a new alternative for cancer treatment; however, its use remains experimental. Here we investigated the utility of adenoviral delivery of interleukin-12 (AdmIL-12) as an adjuvant for PDT in mouse tumour challenge model. PDT was performed by irradiating Radachlorin in C57BL/6 mice transplanted with TC-1 cells. PDT plus AdmIL-12 treatment for tumour suppression as well as specific immune responses were evaluated with the following tests: in vitro and in vivo tumour growth inhibition, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) assay, and cytotoxic T lymphocyte (CTL) assay. Direct intratumoral injection of AdmIL-12 resulted in a significant suppression of tumour growth compared to the control group. Treatment of PDT along with AdmIL-12 further enhanced antitumour effects significantly higher than either AdmIL-12 or PDT alone. This combined treatment resulted in complete regression of 9-mm sized tumour in every animal. We also evaluated immune responses induced by these treatments. Combined treatment significantly increased the production level of IFN-gamma and TNF-alpha compared with that by AdmIL-12 or PDT alone. PDT plus AdmIL-12 enhanced antitumour immunity through increased expansion of the CTL subset mediated by CD8+ T cells. Taken together, these results indicate that the high anti-cancer activity of PDT with AdmIL-12 is a powerful tool against cancer therapy and is a promising subject for further investigation.     

Correlation of Subcellular and Intratumoral Photosensitizer Localization with Ultrastructural Features After Photodynamic Therapy

Photodynamic therapy (PDT) of cancer typically involves systemic administration of tumor-localizing photosensitizers followed 48-72 h later by exposure to light of appropriate wavelengths. Knowledge about the distribution of photosensitizers in tissues is still fragmentary. In particular, little is known as to the detailed localization patterns of photosensitizers in neoplastic and normal tissues as well as the relationship between such patterns and the actual targets for the photosensitizing effect. This review focuses on ultrastructural features seen in treated cells and tumors. An attempt is made to correlate these findings with the subcellular/intratumoral localization pattern of the photosensitizers in tumor cell lines in vitro and in tumor models in vivo. Several subcellular sites are main targets of PDT with different sulfonated aluminum phthalocyanines (AIPcS_n) in the human tumor cell line LOX. Nuclei are not among the primary targets. Overall, the ultrastructural changes correlate well with the data about the subcellular localization patterns for each analogue of AIPcS_n in the same cell line. Similar findings are also obtained for the family of sulfonated mesotetraphenylporphines (TPPS_n) in the NHIK 3025 cell line. The mechanisms involved in the killing of tumors by PDT seem to be a complex interplay between direct and indirect (via vascular damage) effects on neoplastic cells according to the intratumoral localization pattern of the applied dye. Several factors can affect the localization pattern of a drug, such as its chemical character, the mode of drug delivery, the time interval between drug administration and light exposure, and tumor type. Furthermore, whether local immune reactions (such as macrophages) and apoptosis (programmed cell death) are involved in the destruction of neoplastic cells by PDT in vivo is still an enigma. A general model for PDT-induced tumor destruction is suggested.     

Dual imaging-guided photothermal/photodynamic therapy using micelles

We report a type of photosensitizer (PS)-loaded micelles integrating cyanine dye as potential theranostic micelles for precise anatomical tumor localization via dual photoacoustic (PA)/near-infrared fluorescent (NIRF) imaging modalities, and simultaneously superior cancer therapy via sequential synergistic photothermal therapy (PTT)/photodynamic therapy (PDT). The micelles exhibit enhanced photostability, cell internalization and tumor accumulation. The dual NIRF/PA imaging modalities of the micelles cause the high imaging contrast and spatial resolution of tumors, which provide precise anatomical localization of the tumor and its inner vasculature for guiding PTT/PDT treatments. Moreover, the micelles can generate severe photothermal damage on cancer cells and destabilization of the lysosomes upon PTT photoirradiation, which subsequently facilitate synergistic photodynamic injury via PS under PDT treatment. The sequential treatments of PTT/PDT trigger the enhanced cytoplasmic delivery of PS, which contributes to the synergistic anticancer efficacy of PS. Our strategy provides a dual-modal cancer imaging with high imaging contrast and spatial resolution, and subsequent therapeutic synergy of PTT/PDT for potential multimodal theranostic application.     

Comparative examination of the polypeptides of herpes simplex virus: types 1 and 2

Polypeptides synthesized during productive infection of HSV-1 and HSV-2 were found to possess distinct characteristics in regard to localization within the cell, DNA-binding properties, and phosphorylation after synthesis. Continuous labeling for 14 hr or pulse-labeling at successive periods during the replicative cycle with radioactive precursors revealed two types of polypeptide localization: (a) selective accumulation or enhancement within the cytoplasm or nucleus with barely detectable concentrations elsewhere and (b) accumulation in significant concentrations within both cytoplasm and nucleus showing little selective enhancement. Of the polypeptides made during HSV-1 infection 22 were phosphorylated as compared with 16 phosphoproteins specified by HSV-2. Phosphorylation was also implicated in the generation of the four molecular forms comprising the ICP 5–8 complex. Twenty-three polypeptides with affinity for DNA were detected after either type of infection. Sufficient comparisons were made to provide a basis for the tentative listing of 20 polypeptides of HSV-1 with corresponding polypeptides of HSV-2.     

新型卟啉类光敏药物介导的PDT对两种胃癌细胞HGC27和MGC803的杀伤效应

目的 观察本实验室自行合成的新型卟啉类光敏药物对2种人胃癌细胞HGC27和MGC803的光动力学治疗(PDT)作用及作用机制.方法 以人胃癌细胞HGC27和MGC803为实验细胞株.实验分为4组:空白对照组(无药物孵育、无光照),单纯光敏药物组(药物孵育、无光照),单纯光照组(无药物孵育、有光照),光敏药物+光照组(药...     

光动力疗法对慢性牙周炎治疗效果的Meta分析

目的：比较并评价在慢性牙周炎治疗中,光动力疗法辅助龈下刮治和根面平整术（scaling and root planing,SRP）的临床效果是否优于单纯龈下刮治和根面平整术。方法：主要检索OVID、springerlink、ScienceDirect、Pubmed数据库等,收集自建库到2011年11月公开发表的关于光动力疗法辅助龈下刮治和根面平整术治疗慢性牙周炎随机对照试验的英文文献,随访时间不得少于一个月,测量结果包括术后牙周探诊深度（probing depth,PD）的减少、临床附着水平（clinical attach-ment level,CAL）的增加等。采用Jadad法对文章质量进行评价,并使用Revman5.2对实验数据进行Meta分析。结果：共有5篇文献符合纳入条件,Meta分析结果显示光动力学疗法辅助SRP和单纯SRP相比,三个月及六个月后两组之间牙周探诊深度差异无统计学意义,附着丧失也无统计学意义。结论：在慢性牙周炎的治疗过程中,光动力疗法辅助SRP并不能明显降低牙周探针深度和附着丧失。     

Assessment of the subcellular localization of the herpes simplex virus structural protein VP22 in the absence of other viral gene products.

We previously demonstrated that the herpes simplex virus type 1 (HSV-1) structural protein VP22 exists in the cytoplasm early in infection and migrates to and accumulates in the nucleus late in infection (J. Virol. 73(8) (1999) 6769). The goal of this study is to document the behavior of VP22 in cells in the absence of other viral polypeptides. We characterized the effects of various indirect immunofluorescence sample preparation conditions on the localization of VP22 in cells and have determined the following. (i) Fixing with formaldehyde and permeabilizing with acetone maintains the structure of microtubules in cells, in as much as we observed classic microtubule organizing centers. (ii) Acetone or methanol alone did not completely fix the cells. (iii) Triton X-100 decreased tubulin immunofluorescence signals in our system. (iv) VP22 predominated in the nucleus of cells that were fixed with formaldehyde. Based on our results, we conclude the following. (v) Due to the partial fixation by acetone or methanol alone, microtubules form diffuse irregular shapes. (vi) VP22 is detected in the cytoplasm of cells fixed with acetone or methanol only due to its seepage from the nucleus. Taken together, these findings indicate that (vii) the nuclear localization of VP22 does not require additional viral factors.