肿瘤中TOB1功能相关的调控及其潜在的临床应用价值

TOB1基因编码蛋白是TOB/BTG抗增殖蛋白家族成员之一，目前已在多种肿瘤中发现TOB1表达下调、磷酸化积累和亚细胞分布异常。诸多研究表明TOB1基因的表达既受多种上游转录因子的调控，又能通过多种途径调控其下游靶基因的表达来影响肿瘤细胞的增殖、侵袭、转移和凋亡等，与肿瘤的发生发展密切相关。因此，深入探讨肿瘤中TOB1基因表达调控及相关功能改变在临床中的价值具有重要意义。本文旨在阐述TOB1基因及其相关功能的调控机制在临床肿瘤诊疗和预后评估中的潜在应用。     

MicroRNA-34 a对多种肿瘤细胞迁移的影响及其作用机制探讨

MicroRNA-34a是p53信号通路的核心成分,在多种肿瘤中表达下调,被认为是一种抑癌的microRNA,并且与肿瘤干细胞有着密切的联系。MicroRNA-34a可直接抑制多种信息调控因子、细胞周期蛋白的表达,进而抑制细胞增殖、抑制细胞迁移和侵袭、促进细胞衰老和凋亡,从而达到抑癌效果。细胞迁移是肿瘤细胞侵袭和转移的先决条件,是肿瘤发生发展的重要过程。MicroRNA-34a的低表达常见于乳腺癌、前列腺癌、膀胱癌、胃癌、结肠癌、骨癌等,这种低表达往往与细胞迁移能力增强有关,最终加剧肿瘤转移扩散。本文总结了近期关于microRNA-34a对不同种类肿瘤细胞迁移的影响及其作用机制,并进行了分析与归纳。     

下调DNMT1对食管鳞癌EC9706增殖、迁移的影响及相关机制的研究

背景与目的：已有研究显示在多种肿瘤组织或细胞中均能检测出特异性DNA甲基转移酶1（DNA methyltransferase 1,DNMT1）的高表达,提示DNMT1的高表达与肿瘤的发生发展密切相关。本研究旨在通过下调DNMT1基因的表达,研究其对食管鳞癌EC9706细胞的增殖及浸润转移能力的影响,并探讨相关的分子作用机制。方法：利用CCK-8试剂盒研检测下调DNMT1对EC9706细胞增殖能力的影响,并利用Boyden室法检测下调DNMT1对EC9706细胞浸润转移能力,进一步通过Real-time PCR和Western印迹法检测转染DNMT1 siRNA后细胞中DNMT1及MMP-2基因的转录及其蛋白表达。结果：DNMT1 siRNA转染后,能明显抑制食管鳞癌EC9706细胞的增殖,降低其浸润转移能力,引起MMP-2表达下调,提示DNMT1下调引起的浸润转移能力的降低可能与MMP-2表达下调密切相关。结论：DNMT1可能成为食管鳞癌治疗新的分子靶点。     

Eps同源结构域蛋白2在恶性肿瘤中作用研究进展

Eps15同源结构域蛋白2(EHD2)是EHD动力蛋白超级家族中的一员,可广泛调节受体蛋白,在细胞黏附、细胞形态、细胞迁移和胞质分裂等细胞活动过程中起着重要作用。作为新型的膜转运蛋白,EHD2通过调控细胞的内吞作用,参与肿瘤发生发展特别是转移过程。EHD2与乳腺癌、肝癌、食管鳞癌、甲状腺乳头癌、肾透明细胞癌、骨肉瘤等多种癌症密切相关。当EHD2表达异常会调控膜转运过程及下游信号通路,影响上皮间质转化(EMT)的进程,从而调节细胞的迁移、侵袭能力,与肿瘤的发生发展及患者的预后密切相关。本文从EHD2蛋白与肿瘤相关的结构和功能特征、EHD2的生物学功能、EHD2在肿瘤发生发展中的作用及其调控机制、EHD2在肿瘤防治中的意义等方面进行了探讨,认为EHD2是潜在肿瘤治疗靶点。提高对于EHD2在肿瘤发生发展中的作用及调控机制和评估预后的临床价值的认识,将有助于为寻找新的肿瘤诊断标志物和治疗靶点提供思路。     

结直肠癌中C-erbB-2与Ebp1的表达与临床病理特征的关系及其临床意义

目的:研究C-erbB-2与Ebp1蛋白在结直肠癌组织中的表达,并探讨其与结直肠癌临床病理特征的关系及意义。方法:应用免疫组织化学法(EnVision)对65例结直肠癌患者的肿瘤组织及正常结直肠组织分别行C-erbB-2与Ebp1蛋白检测。结果:结直肠癌肿瘤组织中C-erbB-2的表达明显高于正常结直肠组织(P<0.05),Ebp1的表达明显低于正常结直肠组织(P<0.05);结直肠癌肿瘤组织中C-erbB-2与Ebp1表达与患者年龄、性别以及家族史无关,C-erbB-2的高表达与Ebp1的低表达与肿瘤的TNM分期、分化程度以及淋巴结转移呈正相关(P均<0.05);C-erbB-2与Ebp1蛋白表达呈负相关(P<0.05)。结论:C-erbB-2和Ebp1联合检测有助于对肿瘤转移及预后情况的判断,并为以Ebp1作为生物学靶点的肿瘤免疫治疗研究提供依据。     

干扰素诱导的穿膜蛋白家族在肿瘤中的作用及其临床意义

基因表达异常是肿瘤发生发展的重要原因之一,其可导致肿瘤细胞恶性增殖、抵抗凋亡、浸润甚至转移,基因及其编码蛋白的研究有助于加深对肿瘤发生发展的分子机制的认识以及相关基因诊断和治疗的开展。近年来研究显示,干扰素诱导的穿膜蛋白（interferon-induced transmembrane protein,IFITM）家族异常表达与肿瘤的发生发展有关,其中 IFITM1、IFITM2 和IFITM3已被证实在胃癌、乳腺癌、肺癌和肝癌等多种实体肿瘤中高表达,通过调控细胞周期和凋亡相关蛋白的水平,促进肿瘤细胞增殖并抑制凋亡;通过上调基质金属蛋白酶的表达和活性,加速上皮间质转化进程,促进肿瘤细胞的侵袭和转移。IFITM高表达也与患者预后不良显著相关。本综述将围绕IFITM1、IFITM2和IFITM3讨论IFITM在肿瘤发生发展中的作用,阐述其调控机制及在肿瘤诊断和预后预测等方面的临床价值,为寻找新的肿瘤诊断标志物和治疗靶点提供帮助。     

人参皂苷Rh2通过Egr-1/TRL4/mTOR信号通路抑制食管癌细胞Eca-109增殖、迁移和EMT

目的:研究人参皂苷Rh2对食管癌细胞Eca-109增殖、迁移和上皮间质转化（epithelial-mesenchymal transition,EMT）的作用以及作用机制。方法:CCK-8法检测人参皂苷Rh2对食管癌细胞Eca-109增殖的影响;细胞划痕实验检测人参皂苷Rh2对食管癌Eca-109细胞迁移的影响;Western blot检测EMT相关蛋白E-cadherin、Vimentin和Slug的蛋白表达水平。结果:人参皂苷Rh2能够显著抑制Eca-109细胞的增殖,且呈剂量依赖性;此外,人参皂苷Rh2显著抑制E-cadherin、Vimentin和Slug的蛋白表达,并抑制Eca-109细胞迁移;人参皂苷Rh2显著抑制Egr-1、TRL4和mTOR的蛋白表达;进一步的研究结果表明人参皂苷Rh2通过抑制Egr-1/TRL4/mTOR信号通路抑制食管癌细胞Eca-109增殖、迁移和EMT。结论:人参皂苷Rh2能够抑制食管癌细胞Eca-109的增殖、迁移和EMT,其作用机制是通过介导Egr-1/TRL4/mTOR信号通路来实现的。这一结果能够为治疗食管癌的进一步研究提供分子基础。     

piR-hsa-130912促进上皮性卵巢癌细胞增殖、侵袭与迁移及其作用机制

目的 探讨piR-hsa-130912对上皮性卵巢癌（epithelial ovarian cancer, EOC）细胞增殖、侵袭及迁移的调控作用及其分子机制。方法 通过对EOC组织进行BGISEQ UMI Small RNA测序以及RT-qPCR检测,鉴定出piR-hsa-130912。用LV-piR-hsa-130912-up、piR-hsa-130912-inhibitor及相应阴性对照慢病毒感染EOC细胞A2780和SKOV3以干扰piR-hsa-130912表达水平,采用CCK-8、平板克隆实验检测细胞的增殖能力,Transwell侵袭、迁移实验及划痕实验检测细胞的侵袭及迁移能力,Western blot检测肿瘤转移相关蛋白zeb-1、E-cadherin以及vimentin的表达水平。结合RNA测序、GSEA分析、KEGG及GO分析初步探索piR-hsa-130912调控EOC细胞增殖、侵袭及迁移的作用机制。结果 BGISEQ UMI Small RNA测序和RT-qPCR验证结果显示,piR-hsa-130912在EOC组织中高表达。与相应阴性对照组比较,过表达piR-h...     

TNF-ɑ调控LRG1促进乳腺癌MCF-7细胞增殖、侵袭和迁移

目的:研究TNF-α对乳腺癌MCF-7细胞中LRG1蛋白表达的调控及其对乳腺癌MCF-7细胞增殖、侵袭和迁移能力的影响及相关分子机制。方法:MTT实验检测不同浓度TNF-α处理后MCF-7细胞活力;EdU实验、Transwell实验和划痕实验分别检测抑制LRG1表达后细胞增殖、侵袭以及迁移能力;Western blot检测细胞内MAPK信号通路中p-p38蛋白表达。结果:低浓度TNF-α处理乳腺癌MCF-7细胞,细胞活力增强;抑制LRG1表达后细胞增殖能力下降,侵袭细胞数、细胞迁移率以及p-p38蛋白表达均下降。结论:TNF-ɑ通过调控LRG1的表达促进乳腺癌MCF-7细胞增殖、侵袭和迁移,这一过程可能通过激活p38MAPK信号通路来实现。     

朊蛋白在恶性肿瘤中的研究进展及展望

恶性肿瘤是100多种相关疾病的统称,细胞不仅异常快速增殖,而且肿瘤可发生扩散转移;其发生、发展也是由多种生物分子在不同阶段共同参与和调控的一个复杂过程.随着学者对引起肿瘤的相关因素的深入研究,发现朊蛋白与肿瘤之间有着密切关系.阐明朊蛋白形成机制、作用机制与恶性肿瘤的发展、浸润、转移的关系,对恶性肿瘤的诊断、治疗及预后判断有重要意义.     

非小细胞肺癌中PAX6表达及其对肿瘤细胞增殖与侵袭作用机制研究

背景与目的：转录因子PAX6主要表达于胚胎期,不同肿瘤中PAX6呈现高表达,通过不同的信号通路发挥肿瘤抑制或促进作用。检测PAX6在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的表达,通过RNAi下调其表达,研究PAX6对肿瘤细胞侵袭和增殖力以及cyclin E、p38表达水平的影响。方法：应用蛋白印记检测86例NSCLC肿瘤组织及癌旁配对组织以及2例细胞系中PAX6的表达情况。应用PAX6特异性siRNA序列,转染NSCLC细胞系A549,MTT法、Transwell小室、划痕实验检测转染前后细胞增殖、侵袭和迁移能力的对比。蛋白质印记法(Western blot)检测转染前后cyclin E及p38表达情况。结果：对比癌旁组织及正常人支气管上皮细胞16HBE,PAX6在NSCLC组织及A549细胞系中显著高表达。选取高效siRNA序列转染细胞系后,PAX6表达的下调抑制了肿瘤细胞的增殖及集落形成,G1期细胞比例增加,细胞侵袭及迁移力均下降。PAX6基因敲低细胞cyclin E及p38活性受到抑制,表达下调。结论：PAX6通过调控MAPK通路及cyclin E的表达加速肿瘤细胞的增殖、侵袭及迁移,是潜在的NSCLC诊疗靶点。     

华蟾素对人乳腺癌细胞株MDA-MB-231生物学特性的影响

目的:探讨华蟾素(cinobufacini)对人乳腺癌细胞株MDA-MB-231增殖、细胞周期和体外侵袭的影响及其可能机制.方法:用CCK-8试剂盒测定并绘制华蟾素作用后MDA-MB-231细胞的生长曲线,FCM法分析细胞周期分布,Transwell小室检测MDA-MB-231细胞的体外侵袭能力, RT-PCR检测细胞周期素(cyclin)及p21 mRNA的表达变化.结果:华蟾素可抑制MDA-MB-231细胞的增殖能力,其半数抑制浓度(half inhibition concentration, IC50)为 0.31 mg/mL,抑制作用随着华蟾素作用时间的延长而增强,与对照组相比差异有统计学意义(P<0.05);Transwell小室检测表明,华蟾素作用后细胞的侵袭能力比对照组明显下降(P<0.05);FCM分析可见,随着华蟾素浓度的增加,停滞于S期的细胞比率比对照组明显增加(P<0.000 1);华蟾素作用后,MDA-MB-231细胞cyclin A1、cyclin D1和cyclin E1 mRNA的表达水平下降, p21 mRNA的表达水平上升,但cyclin B1 mRNA的表达无明显改变.结论:华蟾素通过调控cyclin A1、cyclin D1、cyclin E1和p21的表达而抑制乳腺癌细胞的增殖和侵袭,并影响其细胞周期的分布.     

The low molecular weight cyclin E isoforms augment angiogenesis and metastasis of human melanoma cells in vivo

Immunohistochemical analysis has consistently shown that cyclin E is up-regulated in human malignant melanomas in vivo. Here we analyzed such expression in more detail and show that cyclin E is overexpressed and present in low molecular weight (LMW) isoforms in metastatic melanoma and in a subset of primary invasive melanoma tumor tissues, but not in benign nevi. Human metastatic melanoma cell lines, but not normal melanocytes, also expressed the LMW cyclin E forms. The biological significance of these findings was established by showing that overexpression of two LMW cyclin E forms named cyclin E truncated 1 [cyclinE(T1)] and cyclin E truncated 2 [cyclinE(T2)] in a low tumorigenic and non-metastatic primary cutaneous melanoma cell line generated angiogenic tumors with prominent perineural invasion compared with full-length cyclin E. In addition, cyclin E(T1)- and cyclin E(T2)-expressing melanoma cells displayed a dramatic increase in the incidence and number of metastases in an experimental lung metastasis assay. Together, these results indicate that the LMW cyclin E forms are functional and likely act as regulators of human melanoma tumor progression and invasion.     

Overexpression of hSNF2H in glioma promotes cell proliferation,invasion, and chemoresistance through its interaction with Rsf-1

hSNF2H partners with Rsf-1 to compose the Rsf complex to regulate gene expression. Recent studies indicated that hSNF2H was overexpressed in several human cancers. However, its expression pattern and biological mechanism in glioma remain unexplored. In this study, we found that hSNF2H was overexpressed in 32 % of glioma specimens. hSNF2H overexpression correlated with advanced tumor grade (p?=?0.0338) and Rsf-1 positivity in glioma tissues (p?=?0.016). Small interfering RNA (siRNA) knockdown was performed in A172 and U87 cell lines. MTT, colony formation assay, and cell cycle analysis showed that knockdown of hSNF2H inhibited cell proliferation, colony formation ability, and cell cycle transition. Matrigel invasion assay showed that hSNF2H depletion inhibited invasive ability of glioma cells. In addition, we demonstrated that hSNF2H depletion decreased temozolomide resistance of A172 and U87 cell lines and increased temozolomide induced apoptosis. Furthermore, hSNF2H depletion decreased cyclin D1, cyclin E, p-Rb, MMP2, cIAP1, Bcl-2 expression, and phosphorylation of IκBα and p65, suggesting hSNF2H regulates apoptosis through NF-κB pathway. Immunoprecipitation showed that hSNF2H could interact with Rsf-1 in both cell lines. To validate the involvement of Rsf-1, we checked the change of its downstream targets in Rsf-1 depleted cells. In Rsf-1 depleted cells, changes of cyclin E, Bcl-2, and p-IκBα were not significant using hSNF2H siRNA treatment. In conclusion, our study demonstrated that hSNF2H was overexpressed in human gliomas and contributed to glioma proliferation, invasion, and chemoresistance through regulation of cyclin E and NF-κB pathway, which is dependent on its interaction with Rsf-1.     

A tumor cell growth inhibitor from Saposhnikovae divaricata

In the present study, we tested ethanolic extracts from 10 Chinese herbs for their effects on K562, Raji, Wish, HeLa, Calu-1, and Vero tumor cells proliferation. On a percentage basis, panaxynol purified from Saposhnikovae divaricata had the highest inhibitory activity on various tumor cells proliferation. Cell-cycle analysis indicated that panaxynol arrested the cell cycle progression of tumor cells from the G1 transition to the S phase. In an attempt to further localize the point in the cell cycle where arrest occurred, gene expression of cyclin E, a key regulatory event leading to the G1/S boundary was examined. Results indicated that the levels of cyclin E mRNA in various tumor cells were decreased by panaxynol. Thus, the suppressant effects of panaxynol on proliferation of various tumor cells appeared to be mediated, at least in part, through impairments of cyclin E mRNA levels and arresting cell cycle progression in the cells.     

Stimulation of hERG1 channel activity promotes a calcium-dependent degradation of cyclin E2, but not cyclin E1, in breast cancer cells

Cyclin E2 gene amplification, but not cyclin E1, has been recently defined as marker for poor prognosis in breast cancer, and appears to play a major role in proliferation and therapeutic resistance in several breast cancer cells. Our laboratory has previously reported that stimulation of the hERG1 potassium channel with selective activators led to down-regulation of cyclin E2 in breast cancer cells. In this work, we demonstrate that stimulation of hERG1 promotes an ubiquitin-proteasome-dependent degradation of cyclin E2 in multiple breast cancer cell lines representing Luminal A, HER2+ and Trastuzumab-resistant breast cancer cells. In addition we have also reveal that hERG1 stimulation induces an increase in intracellular calcium that is required for cyclin E2 degradation. This novel function for hERG1 activity was specific for cyclin E2, as cyclins A, B, D E1 were unaltered by the treatment.Our results reveal a novel mechanism by which hERG1 activation impacts the tumor marker cyclin E2 that is independent of cyclin E1, and suggest a potential therapeutic use for hERG1 channel activators.     

A Tumor Cell Growth Inhibitor from Saposhnikovae divaricata

In the present study, we tested ethanolic extracts from 10 Chinese herbs for their effects on K562, Raji, Wish, HeLa, Calu-1, and Vero tumor cells proliferation. On a percentage basis, panaxynol purified from Saposhnikovae divaricata had the highest inhibitory activity on various tumor cells proliferation. Cell-cycle analysis indicated that panaxynol arrested the cell cycle progression of tumor cells from the G1 transition to the S phase. In an attempt to further localize the point in the cell cycle where arrest occurred, gene expression of cyclin E, a key regulatory event leading to the G1/S boundary was examined. Results indicated that the levels of cyclin E mRNA in various tumor cells were decreased by panaxynol. Thus, the suppressant effects of panaxynol on proliferation of various tumor cells appeared to be mediated, at least in part, through impairments of cyclin E mRNA levels and arresting cell cycle progression in the cells.     

Cancer-testis antigen MAGE-C2 binds Rbx1 and inhibits ubiquitin ligase-mediated turnover of cyclin E

Cancer-testis antigen MAGE-C2 is normally expressed in testis but aberrantly expressed in various kinds of tumors. Its functions in tumor cells are mostly unknown. Here, we show that MAGE-C2 binds directly to the RING domain protein Rbx1, and participates in Skp1-Cullin1-F box protein (SCF) complex. Furthermore, MAGE-C2 can inhibit the E3 ubiquitin ligase activity of SCF complex. Ablation of endogenous MAGE-C2 decreases the level of cyclin E and accelerates cyclin E turnover by inhibiting ubiquitin-mediated proteasome degradation. Overexpression of MAGE-C2 increases the level of cyclin E and promotes G1-S transition and cell proliferation, and the results are further confirmed by knockdown of MAGE-C2. Overall, the study indicates that MAGE-C2 is involved in SCF complex and increases the stability of cyclin E in tumor cells.