局部晚期非小细胞肺癌βⅢ -ｔｕｂｕｌｉｎ和Ｓｔａｔｈｍｉｎ的表达及与紫杉醇耐药性关系的研究

目的：探讨局部晚期非小细胞肺癌（ＮＳＣＬＣ）βⅢ-ｔｕｂｕｌｉｎ和Ｓｔａｔｈｍｉｎ表达与紫杉醇化疗耐药性关系。方法：回顾性分析８４例接受紫杉醇化疗的局部晚期ＮＳＣＬＣ患者的临床病理资料。免疫组织化学法检测肿瘤标本βⅢ-ｔｕｂｕｌｉｎ和Ｓｔａｔh-ｍｉｎ蛋白的表达,并对疗效进行分析。结果：βⅢ-ｔｕｂｕｌｉｎ阳性表达率为４８.８１％（４１／８４）,Ｓｔａｔｈｍｉｎ阳性表达率为５１.１９％（４３／８４）,均与性别、年龄及组织类型无关。化疗有效率（ＣＲ＋ＰＲ）为４１.６７％,βⅢ-ｔｕｂｕｌｉｎ高表达的患者有效率低（２４.３９％）,进展率高（１３.８９％）;βⅢ-ｔｕｂｕｌｉｎ低表达患者有效率高（５８.１４％）,进展率低（０）,差异均有显著性（Ｐ＜０.０１）。Ｓｔａｔｈｍｉｎ（＋）组的有效率为２７.９１％,低于Ｓｔａｔｈｍｉｎ（－）组的５６.１０％,而其进展率为１１.６３％,高于Ｓｔａｔｈｍｉｎ（－）组０,差异均有显著性（Ｐ＜０.０５）。联合检测显示：βⅢ-ｔｕｂｕｌｉｎ（＋）且Ｓｔａｔｈｍｉｎ（＋）组有效率为２１.８８％,βⅢ ｔｕｂｕｌｉｎ（－）且Ｓｔａｔｈｍｉｎ（－）组有效率为６２.５０％,两者差异显著（Ｐ＜０.０１）。结论：βⅢ-ｔｕｂｕｌｉｎ和Ｓｔａｔｈｍｉｎ高表达的局部晚期ＮＳＣＬＣ患者对紫杉醇化疗耐药。     

Stathmin基因表达与肿瘤的研究进展

Stathmin在多种恶性肿瘤细胞中都有高水平表达，Stathmin蛋白的主要作用是通过促进微管的解聚或阻止微管的聚合从而影响有丝分裂纺锤体的形成，通过抑制其表达可以干扰恶性肿瘤细胞的有丝分裂，影响肿瘤细胞的增殖与凋亡。同时，抑制stathmin表达能够协同增效某些化疗药物的抗癌疗效。Stathmin基因正成为肿瘤基因治疗的一个新靶点。     

Stathmin蛋白的研究进展

Stathmin蛋白由于其特有的微管解聚活性,在细胞的增殖和分化及肿瘤发生中有十分重要的作用.抑制Stathmin蛋白的表达已经成为肿瘤基因治疗的新的靶点,并且已经证实Stathmin蛋白能够影响某些作用于微管的化疗药物的疗效,对于指导临床用药有一定的意义.Stathmin蛋白还能够促进神经系统的发育,因此受到更多的关注.     

紫杉醇耐药与β微管蛋白Ⅲ研究进展

 紫杉醇依赖于促进微管聚合,抑制微管解聚,诱导肿瘤细胞凋亡,但肿瘤细胞对紫杉醇的耐药性是限制其临床应用的重要因素。一些基础、临床研究均证实β微管蛋白Ⅲ高表达与紫杉醇耐药、预后不良密切相关。     

紫杉醇动脉灌注治疗非小细胞肺癌疗效观察

紫杉醇是一类新型抗微管药物,通过促进微管蛋白聚合,抑制解聚,保持微管蛋白稳定,抑制细胞有丝分裂,达到抑制肿瘤生长作用.但因其有较高的过敏反应发生率,限制了其应用途径.我科于2005年10月至2007年8月对32例晚期非小细胞肺癌患者给予含紫杉醇方案的动脉灌注化疗,对于其近期疗效及副反应进行观察,现报告如下.     

盖诺联合顺铂治疗乳腺癌27例临床观察

长春瑞宾为半合成的长春碱类抗癌药物,通过阻滞微管蛋白聚合形成微管,并诱导微管解聚,从而使细胞分裂停止于有丝分裂中期,属于细胞周期特异性药物.我院于2002年5月～2003年5月采用国产长春瑞宾联合顺铂治疗晚期或转移性乳腺癌27例,观察其疗效及毒副作用,现将结果报告如下:     

微管及其靶向制剂在骨肉瘤细胞凋亡中的研究进展

微管是一种由α和β微管蛋白异二聚体构建而成的中空管状纤维，可在细胞有丝分裂时形成纺锤体，在染色体分裂及其双向、多向移位中发挥重要作用。研究表明，微管参与了骨肉瘤细胞的有丝分裂，其靶向制剂可通过抑制微管聚合（促解聚）或抑制微管解聚（促聚合）作用于微管蛋白，从而诱导细胞凋亡。目前微管靶向制剂已广泛应用于骨肉瘤治疗，且取得较好的临床疗效。本文就微管及其靶向制剂与骨肉瘤细胞凋亡关系的研究进展作一综述。     

紫杉醇疗效预测分子研究进展

紫杉醇（Taxol，Paclitaxel）是从太平洋紫杉树树皮中分离出来的广泛使用的一种化疗药物，是目前已知的最有效的抗肿瘤化疗药物之一。它同形成有丝分裂纺锤体的微管上的B微管蛋白结合，通过促进微管蛋白组装和稳定微管，阻止微管解聚，从而抑制细胞增殖和诱导细胞凋亡。然而并不是所有的肿瘤都对紫杉醇敏感，而敏感和耐药的肿瘤特征又不能很好的判断，所以对紫杉醇疗效的预测具有很大的临床价值，本文试对各种分子对紫杉醇的疗效预测作一个综述。     

非小细胞肺癌β-ｔｕｂｕｌｉｎⅢ表达与微管蛋白结合类化疗药物敏感性的关系

目的　探讨进展期非小细胞肺癌（ＮＳＣＬＣ）组织β微管蛋白Ⅲ（β-ｔｕｂｕｌｉｎⅢ）的表达情况及其与含微管蛋白结合类化疗药物敏感性之间的关系。方法　收集２００２年１月至２００６年１２月经病理组织学检查确诊的ⅢＢ、Ⅳ期ＮＳＣＬＣ初治患者１２０例,采用免疫组化法检测活检癌组织中β-ｔｕｂｕｌｉｎⅢ的表达。所有患者行４～６个周期异长春花碱或紫杉类联合顺铂化疗,评价治疗有效率（ＲＲ）,随访总生存时间（ＯＳ）和肿瘤进展时间（ＴＴＰ）,分析上述指标以及临床特征与β-ｔｕｂｕｌｉｎⅢ表达之间的关系。结果　５３例患者均可评价疗效。β-ｔｕｂｕｌｉｎⅢ高表达者（ｎ＝３１）的ＲＲ、ＯＳ、ＴＴＰ分别为９．４％、（２７７.２６±１１２.８２）天和（１７０.０６±７１.４５）天,均显著低于β-ｔｕｂｕｌｉｎⅢ低表达者（ｎ＝２２）的４５.５％、（４５７.３２±２０７.１２）天和（２８９.４５±１２９.７８）天（Ｐ＜０.００１）。β-ｔｕｂｕｌｉｎⅢ表达与性别、年龄、病理类型、吸烟情况、ＴＮＭ分期、基础疾病情况、合并症、癌症家族史、ＰＳ评分等临床病理特征均无关。结论　进展期ＮＳＣＬＣ的β-ｔｕｂｕｌｉｎⅢ表达情况可能与接受微管蛋白结合类化疗药物的敏感性有关,低表达者疗效及预后均优于高表达者。β-ｔｕｂｕｌｉｎⅢ表达与临床病理特征无关。     

长春瑞宾外渗致皮肤坏死的护理

长春瑞宾又名去甲长春花碱,商品名盖诺,属细胞周期特异性药物,主要作用于肿瘤细胞的DNA合成后期,阻止微管蛋白聚合形成微管,同时诱导微管解聚,使肿瘤细胞的有丝分裂增殖停止于有丝分裂的中期,达到抗肿瘤目的.     

Effect of stathmin on the sensitivity to antimicrotubule drugs in human breast cancer

Stathmin is a p53-regulated protein known to influence microtubule dynamics. Because several chemotherapeutic agents used to treat breast cancer alter the dynamic equilibrium of tubulin polymerization, stathmin may play an important role in determining the sensitivity to these drugs. Therefore, we evaluated the effect of stathmin expression on the action of taxanes and Vinca alkaloids using a panel of human breast cancer cell lines. Cell lines harboring mutant p53 expressed high levels of stathmin. Two cell lines with different levels of endogenous stathmin expression and isogenic-paired cell lines transfected to overexpress stathmin were used to determine whether or not stathmin modulated the sensitivity to drugs. Overexpression of stathmin decreased polymerization of microtubules, markedly decreased binding of paclitaxel, and increased binding of vinblastine. Stathmin overexpression decreased sensitivity to paclitaxel and, to a lesser extent, to vinblastine. In contrast, stathmin content had no significant effect on the sensitivity to chemotherapeutic drugs that do not target microtubules. Cell lines overexpressing stathmin were more likely to enter G(2) but less likely to enter mitosis as determined by fluorescence-activated cell sorting and mitotic index. This effect was magnified when stathmin-overexpressing cells were treated with vinblastine as measured by the detection of proteins phosphorylated in early mitosis. These data suggest that the action of antimicrotubule drugs can be affected by stathmin in at least two ways: (a) altered drug binding; and (b) growth arrest at the G(2) to M boundary. Mutant p53 breast cancers exhibiting high levels of stathmin may be resistant to antimicrotubule agents.     

Synergistic augmentation of antimicrotubule agent-induced cytotoxicity by a phosphoinositide 3-kinase inhibitor in human malignant glioma cells

Because the aberrantly activated phosphoinositide 3-kinase (PI3K)/Akt pathway renders tumor cells resistant to cytotoxic insults, including those related to anticancer drugs, inhibition of the pathway may possibly restore or augment the effectiveness of chemotherapy. Using the human malignant glioma cell lines U87, A172, LN18, and LN229, we examined effects of the PI3K inhibitor LY294002 on both apoptosis and cytotoxicity induced by chemotherapeutic agents, including antimicrotubule agents vincristine and paclitaxel, an alkylating agent 1,3-bis(2-chloroethyl)-1-nitrosourea, a topoisomerase II inhibitor etoposide, and a DNA cross-linking agent cisplatin (cis-diamminedichloroplatinum), and we compared the LY294002-induced enhancement of effects of those agents. Ten to 20 micro M LY294002 augmented both apoptosis and caspase 3-like activity caused by antimicrotubule agents to a larger extent than induced by 1,3-bis(2-chloroethyl)-1-nitrosourea, etoposide, and cisplatin in all four malignant glioma cell lines examined. The same doses of LY294002 enhanced cytotoxicity more efficiently with antimicrotubule agents than with other chemotherapeutic agents. Quantitative analyses using a modified isobologram and median effect plot method revealed that enhancement by LY294002 of vincristine- or paclitaxel-induced cytotoxicity was synergistic, whereas enhancement by the PI3K inhibitor of the other chemotherapeutic agent-induced cytotoxicity was additive. Our study indicates that the synergistic augmentation of the cytotoxicity by LY294002 occurs specifically with antimicrotubule agents, at least partially through an increase in caspase 3-dependent apoptosis, and we suggest that inhibitors of the PI3K/Akt pathway in combination with antimicrotubule agents may induce cell death effectively and be a potent modality to treat patients with malignant gliomas.     

微管不稳定蛋白Stathmin--肿瘤基因治疗新靶点

微管不稳定蛋白Stathmin在细胞周期的不同阶段对微运动力平衡的调节发挥重要作用。多种恶性肿瘤中Stathmin都有高水平表达，抑制其表达可以干扰恶性细胞的细胞分裂、Stathmin的过表达可干扰紫杉醇与微管的结合，但增加长春碱类药物与微管的结合能力，临床用药时应予考虑。另外．Stathmin为肿瘤基因治疗提供了一个分子新靶点，腺病毒介导抗stathmin核酶治疗联合察素药物治疗可能获得更强有力的抗增殖和抗肿瘤效应。     

PIWIL1 destabilizes microtubule by suppressing phosphorylation at Ser16 and RLIM-mediated degradation of stathmin1

Human PIWIL1, alias HIWI, is a member of Piwi protein family and expressed in various tumors. However, the underlying mechanism of PIWIL1 in tumorigenesis remains largely unknown. Stathmin1 is a cytosolic phosphoprotein which has a critical role in regulating microtubule dynamics and is overexpressed in many cancers. Here we report that PIWIL1 can directly bind to Stathmin1. Meanwhile, PIWIL1 can up-regulate the expression of Stathmin1 through inhibiting ubiquitin-mediated degradation induced by an E3 ubiquitin ligase RLIM. Furthermore, PIWIL1 can also reduce phosphorylation level of Stathmin1 at Ser-16 through inhibiting the interaction between CaMKII and Stathmin1. Our results showed that PIWIL1 suppresses microtubule polymerization, and promotes cell proliferation and migration via Stathmin1 for the first time. Our study reveals a novel mechanism for PIWIL1 in tumorigenesis.     

A combination of paclitaxel and siRNA-mediated silencing of Stathmin inhibits growth and promotes apoptosis of nasopharyngeal carcinoma cells

Background

Stathmin, a microtubule associated protein (MAP), is an important molecular target for cancer therapy. Paclitaxel is one of the primary antitumor drugs targeting microtubules (MTs). We hypothesized that decreasing the expression level of Stathmin might improve the effectiveness of paclitaxel in the treatment of nasopharyngeal carcinoma (NPC).

Methods

NPC cell lines, CNE1-LMP1 and HNE2, and a CNE1-LMP1 tumor xenograft mouse model were used to test both in vitro and in vivo our siRNA-based Stathmin silencing strategy. The effects of Stathmin silencing on cell proliferation, apoptosis, and viability were investigated using MTT, AO/EB staining, TUNEL, caspase protein detection, and FCM assays. Cell migration and invasion were assayed using a Transwell assay. The combined effects of Stathmin silencing and paclitaxel were investigated using MTT, FCM, Western blot and indirect immunofluorescence assays. The effect of paclitaxel on Stathmin expression in NPC cells and, in addition, A375, MGC and HeLa cells was determined by RT-PCR and Western blotting.

Results

We found that siRNA-mediated silencing of Stathmin suppresses proliferation, induces apoptosis through the mitochondrial pathway, and causes G2/M-phase cell cycle arrest in the NPC cell lines CNE1-LMP1 and HNE2. Also, the migration and invasion of the respective NPC cells were found to be inhibited. In addition, we show that a combination of Stathmin silencing and paclitaxel is more effective than either agent alone in inhibiting proliferation and inducing apoptosis, cell cycle arrest, and MT polymerization. Furthermore, we found that Stathmin expression in the tumor cells is down-regulated by paclitaxel treatment.

Conclusion

siRNA-mediated silencing of Stathmin suppresses the proliferation, invasion and metastasis, and induces the apoptosis of NPC cells. Paclitaxel reduces the expression of Stathmin, and combining Stathmin silencing with paclitaxel treatment enhances MT polymerization. This combined strategy may provide a new approach for clinical NPC treatment.     

Stathmin 1 inhibition amplifies ruxolitinib-induced apoptosis in JAK2V617F cells

The JAK/STAT pathway is constitutively activated in myeloproliferative neoplasms and can be inhibited by ruxolitinib, a selective JAK1/2 inhibitor. The JAK2^V617F mutation leads to constitutive STAT3 phosphorylation and potentially leads to inhibition of Stathmin 1 activity via STAT3. In support of this hypothesis, we found that, in HEL JAK2^V617F cells, ruxolitinib treatment decreased STAT3 and Stathmin 1 association, induced Stathmin 1 activation and microtubule instability. Silencing of Stathmin 1 significantly reduced cell proliferation and clonal growth, and increased apoptosis induced by ruxolitinib. Stathmin 1 silencing also prevented ruxolitinib-induced microtubule instability. To phenocopy the effect of Stathmin 1 inhibition, cells were treated with paclitaxel, a microtubule-stabilizing drug, in association or not with ruxolitinib; combined treatment significantly increased apoptosis, when compared to monotherapy. Notably, Stathmin 1 mRNA levels were highly expressed in CD34⁺ cells from primary myelofibrosis patients. We then proposed that an undesired effect of ruxolitinib treatment may constitute Stathmin 1 activation and microtubule instability in JAK2^V617F cells. Induction of microtubule stability, through Stathmin 1 silencing or paclitaxel treatment, combined with ruxolitinib could be an effective strategy for promoting apoptosis in JAK2^V617F cells.     

A Phase I/pilot study of sequential doxorubicin/vinorelbine: effects on p53 and microtubule-associated protein 4.

PURPOSE: Few molecular determinants of sensitivity to cancer chemotherapy exist. In experimental systems, p53 regulates the sensitivity to antimicrotubule drugs through its effect on microtubule-associated protein 4 (MAP4). MAP4 is the major microtubule-associated protein in nonneuronal tissues and promotes microtubule polymerization. We reported that wild-type p53 induction by doxorubicin in C127 breast cancer cells repressed MAP4, decreased microtubule polymerization, and increased Vinca alkaloid sensitivity. The goals of this Phase I/pilot clinical trial were to determine: (a) the safety of delivering a DNA-damaging agent (doxorubicin) followed in sequence by treatment with an antimicrotubule drug (vinorelbine); and (b) the feasibility of detecting activation of p53 and repression of MAP4 in patients' tissues. EXPERIMENTAL DESIGN: Peripheral blood mononuclear cells (PBMNCs) and tumor were obtained from 16 women with locally advanced (stage IIIb) or metastatic (stage IV) breast cancer before doxorubicin treatment and immediately before treatment with vinorelbine 24 or 48 h later. RESULTS: After doxorubicin treatment, p53 increased in 12 of 14 PBMNC and 4 of 10 tumor samples. Changes in MAP4 were variable; however, in samples in which p53 was induced, MAP4 decreased in 7 of 12 PBMNC and 3 of 4 breast cancer specimens. Immunohistochemistry confirmed lower MAP4 expression in tumor cells after doxorubicin treatment. Seven of 16 patients had a partial response, and treatment was well tolerated. CONCLUSIONS: These data demonstrate the ability to detect the activation of p53 and the repression of MAP4 in normal and malignant tissues in patients treated with a DNA-damaging agent, and that an antimicrotubule drug can be administered safely at a time when cells may be more sensitive to treatment.     

Stathmin蛋白:一个潜在的肿瘤标志物

人stathmin也称原癌基因蛋白18(oncogene protein 18, Op18), 是一种广泛存在于细胞质的蛋白质,其相对分子质量约为19×10~3,可与微管蛋白结合,参与微管和纺锤体的组装;与细胞的增殖、分化、再生和运动均有关,并具有信号活性调节的功能.近年来有研究发现,stathmin在多种肿瘤中高表达,并可通过调节微管的解聚,促进肿瘤细胞的运动及侵袭.Stathmin翻译后修饰状态的改变,可影响与p53蛋白的相互作用,参与肿瘤的发生发展.目前单独或者联合化疗药物使用的抗stathmin效应剂已用于某些肿瘤的治疗.虽然stathmin与肿瘤病因学的内在联系尚不十分清楚,但其作为一个潜在的肿瘤标志物或药物靶点值得进一步研究探讨.     

Apoptotic mechanisms induced in breast cancer cells by vinorelbine

Vinorelbine (VNB) is one of new semi-synthesized vinka alkaloids developed in France, of which anti-tumor activity is susceptible mainly to non-small cell lung cancer and breast cancer. Moreover, its clinical efficacy has been noted from single-agent therapy or combination therapy with taxanes. It is assumed that VNB selectively acts on tubulin which elaborates microtubules, strands the cells at G 1 phase and interferes with the mitosis. VNB has unique anti-tumor activity as an antimicrotubule agent and is expected to be available for treatment of multi-drug resistant tumors. In this report, we demonstrate that VNB, as an antimicrotubule agent, induces apoptosis in breast cancer cell line, MX-1 via a mitochondrial pathway.