盐霉素对头颈部鳞状细胞癌Fadu细胞增殖和侵袭的影响

目的：研究盐霉素对头颈部鳞状细胞癌（HNSCC）Fadu细胞增殖和侵袭的影响,初步探讨盐霉素在HN－SCC发生发展中的作用。方法：不同浓度盐霉素（2、4、8、16μMmol／L）作用于Fadu细胞,分别处理12、24、36、48 h,用MTT法检测盐霉素对Fadu细胞增殖的影响,Transwell小室法测定盐霉素对Fadu细胞迁移和侵袭能力的影响;Western blot法检测盐霉素对Fadu细胞中基质金属蛋白酶－7（MMP－7）、基质金属蛋白酶－9（MMP－9）和基质金属蛋白酶－13（MMP－13）蛋白表达的影响。结果：盐霉素呈时间－剂量依赖性抑制Fadu细胞的增殖（P＜0．05）,使Fadu细胞的迁移和侵袭能力明显下降。盐霉素还使MMP－7和MMP－9蛋白的表达水平下调（P＜0．05）。结论：盐霉素可以降低Fadu细胞的增殖能力,抑制该肿瘤细胞的迁移和侵袭能力,迁移和侵袭能力的改变可能与下调MMP－7和MMP－9的蛋白表达有关。     

盐霉素对鼻咽癌CNE-2细胞放射敏感性的影响

目的:体外实验研究盐霉素对鼻咽癌CNE-2细胞放射敏感性的影响。方法:通过CCK-8法检测盐霉素作用后鼻咽癌CNE-2细胞的增殖情况。利用克隆集落形成实验观察鼻咽癌细胞成活情况，单击多靶模型拟合剂量存活曲线，计算放射增敏指数（SER）；Chou-Talalay数学模型绘制联合指数（CI）曲线，判断盐霉素和放射的作用关系。利用γ-H2AX焦点形成检测DNA分子损伤情况。结果:盐霉素能够抑制鼻咽癌细胞的增殖，并且具有明显的时间和剂量依赖性；盐霉素作用鼻咽癌细胞的IC50值在24 h时为17.81 μmol/L，48 h时为3.98 μmol/L。根据单击多靶模型拟合细胞的存活曲线，可知在鼻咽癌细胞CNE-2中盐霉素浓度为0.1 μmol/L和0.5 μmol/L时SER分别为1.19和1.21，均大于1.0，表明盐霉素对鼻咽癌细胞具有明显的放射增敏作用。制作联合指数（CI）曲线，可知在盐霉素浓度为0.1 μmol/L时，放射剂量为2 Gy时，CI值≈1，盐霉素和放射对CNE-2的作用接近相加作用，放射剂量为4、6、8 Gy时，CI值均＜1，二者为协同作用；在盐霉素浓度为0.5 μmol/L时，放射剂量为2、4、6、8 Gy时，CI值均＜1，二者均为协同作用。相对于照射组，盐霉素+照射组能增加DNA损伤数目。结论:盐霉素能提高鼻咽癌细胞的放射敏感性，为一种潜在的放射增敏药物。     

Combination therapy targeting both cancer stem-like cells and bulk tumor cells for improved efficacy of breast cancer treatment

Many types of tumors are organized in a hierarchy of heterogeneous cell populations. The cancer stem-like cells (CSCs) hypothesis suggests that tumor development and metastasis are driven by a minority population of cells, which are responsible for tumor initiation, growth and recurrences. The inability to efficiently eliminate CSCs during chemotherapy, together with CSCs being highly tumorigenic and invasive, may result in treatment failure due to cancer relapse and metastases. CSCs are emerging as a promising target for the development of translational cancer therapies. Ideal panacea for cancer would kill all malignant cells, including CSCs and bulk tumor cells. Since both chemotherapy and CSCs-specific therapy are insufficient to cure cancer, we propose combination therapy with CSCs-targeted agents and chemotherapeutics for improved breast cancer treatment. We generated in vitro mammosphere of 2 breast cancer cell lines, and demonstrated ability of mammospheres to grow and enrich cancer cells with stem-like properties, including self-renewal, multilineage differentiation and enrichment of cells expressing breast cancer stem-like cell biomarkers CD44⁺/CD24^?/low. The formation of mammospheres was significantly inhibited by salinomycin, validating its pharmacological role against the cancer stem-like cells. In contrast, paclitaxel showed a minimal effect on the proliferation and growth of breast cancer stem-like cells. While combination therapies of salinomycin with conventional chemotherapy (paclitaxel or lipodox) showed a potential to improve tumor cell killing, different subtypes of breast cancer cells showed different patterns in response to the combination therapies. While optimization of combination therapy is warranted, the design of combination therapy should consider phenotypic attributes of breast cancer types.     

盐霉素通过TGFβ1/Smad信号通路抑制MMP-2、9降低CD44~+/CD24~(-/low)表型乳腺癌干细胞迁移和侵袭能力

目的分析盐霉素对CD44~+ /CD24~(-/low)表型乳腺癌干细胞迁移和侵袭能力的影响,并初步探讨其影响机制。方法通过有血清和无血清培养技术培养人乳腺癌MCF-7细胞株,收集两种细胞,对其CD24、CD44标志物进行荧光染色,采用流式细胞仪检测CD44~+ /CD24~(-/low)亚群细胞的比例;盐霉素培养MCF-7细胞株和CD44~+ /CD24~(-/low)表型乳腺癌干细胞,MTT法筛选出引起CD44~+ /CD24~(-/low)表型乳腺癌干细胞细胞凋亡低于IC50的浓度;Transwell技术检测MCF-7和CD44~+ /CD24~(-/low)表型乳腺癌干细胞的迁移和侵袭能力,以筛选出的浓度诱导CD44~+ /CD24~(-/low)表型乳腺癌干细胞,以排除盐霉素对该细胞增殖抑制作用的影响,Transwell技术检测该细胞迁移和侵袭能力的变化;Western blot技术检测TGFβ1、Smad2、Smad3、p-Smad2、pSmad3、MMP-2、MMP-9蛋白水平的变化。结果 CD44~+ /CD24~(-/low)表型乳腺癌干细胞在无血清培养和有血清培养中的比例分别为(86.93±0.53)%和(19.98±0.62)%(P0.01),CD44~+ /CD24~+ 表型细胞的比例分别是(12.68±0.59)%和(79.90±0.57)%(P0.01);MTT法筛选出低于IC50的浓度是1、3、5、7μmol/L;Transwell技术检测CD44~+ /CD24~(-/low)表型乳腺癌干细胞迁移和侵袭能力明显高于MCF-7细胞株,并随盐霉素浓度的上升呈下降趋势(P0.05)。Western blot技术检测TGFβ1、Smad2、Smad3、p-Smad2、p-Smad3、MMP-2、MMP-9蛋白水平下调(P0.01)。结论盐霉素可能通过TGFβ1/Smad信号通路下调MMP-2、MMP-9蛋白水平,从而降低CD44~+ /CD24~(-/low)表型乳腺癌干细胞迁移和侵袭能力。     

Salinomycin overcomes acquired tamoxifen resistance through AIB1 and inhibits cancer cell invasion in endocrine resistant breast cancer

Salinomycin is a monocarboxylic polyether ionophore isolated from Streptomyces albus. It has been widely used as an antibiotic in veterinary medicine in poultry. A recent study demonstrated that salinomycin selectively inhibits human breast cancer stem cells; one possible mechanism of tamoxifen resistance. Our results show that salinomycin is effective in inhibiting MCF‐7/LCC2 and MCF‐7/LCC9 cell lines which are well‐established endocrine resistant cells and has a synergistic effect in combination with tamoxifen using MTT proliferation assay. The inhibitory effect of salinomycin on the reduction of critical ER co‐activator; amplified breast 1 (AIB1) mRNA and protein expression is overcoming tamoxifen resistance . Moreover, salinomycin significantly inhibits cell invasion in Matrigel invasion assay. The effect was mediated at least in part by the decrease of matrix metalopeptidase 9 (MMP‐9) which is one critical enzyme facilitated in the cell invasion process. In conclusion, salinomycin should be developed as a novel agent used alone or in combination for endocrine‐resistant breast cancer.     

盐霉素钠纳米脂质体的制备及表征

目的制备并表征盐霉素钠纳米脂质体(SLN)。方法采用薄膜分散法制备盐霉素钠纳米脂质体,通过调节脂质体中胆固醇比例,以盐霉素钠包封率为评价指标,筛选盐霉素钠纳米脂质体的优化处方。结果透射电镜显示盐霉素钠纳米脂质体形态圆整,分散性良好,激光粒度仪显示盐霉素钠纳米脂质体平均粒径为99.0nm,Zeta电位为-33.5mV,包封率为85.7%,载药量为6.7%。通过脂质体包裹,盐霉素钠在水中的最高浓度可提高15倍,并证明其具有一定缓释效果。结论笔者得到了粒径大小在100nm左右,形态均一,包封率和载药量较高的盐霉素钠纳米脂质体,为进一步测定其杀伤肿瘤活性奠定了坚实的制剂学基础。     

In Vitro Antiviral Activities of Salinomycin on Porcine Epidemic Diarrhea Virus

Porcine epidemic diarrhea virus (PEDV), an enteropathogenic coronavirus, has catastrophic impacts on the global pig industry. Owing to the lack of effective vaccines and specific therapeutic options for PEDV, it is pertinent to develop new and available antivirals. This study identified, for the first time, a salinomycin that actively inhibited PEDV replication in Vero cells in a dose-dependent manner. Furthermore, salinomycin significantly inhibited PEDV infection by suppressing the entry and post-entry of PEDV in Vero cells. It did not directly interact with or inactivate PEDV particles, but it significantly ameliorated the activation of Erk1/2, JNK and p38MAPK signaling pathways that are associated with PEDV infection. This implied that salinomycin inhibits PEDV replication by altering MAPK pathway activation. Notably, the PEDV induced increase in reactive oxidative species (ROS) was not decreased, indicating that salinomycin suppresses PEDV replication through a pathway that is an independent pathway of viral-induced ROS. Therefore, salinomycin is a potential drug that can be used for treating PEDV infection.     

Detection of coccidiostats by immunoassay

Coccidiosis is a complex disease that affects many farm animals, but which can be especially serious in poultry. Control of coccidiosis is essential for efficient, modern poultry productions; thus coccidiostats are extensively used to control this disease. The most commonly used coccidiostats in poultry are the polyether monocarboxylic ionophores including monensin and salinomycin. Polyether ionophores also improve feed utilization by ruminants. However, the quantity of such ionophores for effective control of coccidiosis in chickens may prove highly toxic to other agriculturally important animals. Over the past few years, we have developed monoclonal antibody‐based immunoassays for both salinomycin and monensin. In addition, we have developed immunoassays for dimetridazole and for halofuginone, the latter being a heavily used non‐ionophore coccidiostat. The advantages of the immunoassays over the conventional analytical methods are discussed as well as the characteristics of the individual immunoassays.     

盐霉素联合奥沙利铂对PANC89的增殖及诱导凋亡的机制

目的研究盐霉素对人胰腺癌细胞株PANC89的增殖及诱导凋亡的影响及其联合奥沙利铂后增敏其抗肿瘤的作用及机制。方法采用CCK-8法及Hoechst 33342染色法,分别检测盐霉素及盐霉素联合奥沙利铂对PANC89细胞生长的抑制、凋亡的影响;并且用流式细胞术检测细胞凋亡率。Real—time PCR和Westernblot用于分析盐霉素处理后相关基因的mRNA和蛋白表达水平。结果盐霉素抑制PANC89的增殖,且可增敏奥沙利铂抗胰腺癌作用;经过盐霉素联合奥沙利铂处理后,胰腺癌细胞的凋亡率增加（P〈0．05）。经盐霉素以及联合奥沙利铂作用后Bax、Bak的表达明显增加,而Bcl-2及Bcl—x及β—cateninandp-GSK-3p的表达亦被明显抑制（P〈0．05）。结论盐霉素可抑制PANC89的增殖,增敏奥沙利铂的抗肿瘤作用,通过Bcl-2途径诱导人胰腺癌细胞株PANC89的凋亡,并且这可能是通过对Wnt／β—catenin通路的抑制产生的。