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乳腺癌作为常见肿瘤,多发于女性,已经严重威胁女性的身心健康。现阶段,乳腺癌在女性中的发病率呈逐步上升的趋势。作为乳腺癌的严重类型,三阴性乳腺癌(triple negative breast cancer,TNBC)是指雌激素受体(ER)、孕激素受体(PR)、人类表皮生长因子受体2(HER-2)阴性的乳腺癌, 占所有乳腺癌的9%~16%, 好发于年轻女性(< 50岁者多见)[1-2]。TNBC具有高侵袭性、复发较早及高远处转移率的特点, 与此同时,TNBC的5年生存率和总生存率较低, 预后相对较差[3]。目前, TNBC主要有手术治疗、化学药物治疗、放射治疗等, 与其他类型乳腺癌相比并无特殊之处, 但是由于TNBC的分子靶点为阴性,所以对于TNBC病人来说,内分泌治疗与分子靶向治疗效果不理想。因此, TNBC研究的重点是寻找提高乳腺癌治疗效果方法和降低乳腺癌复发转移。肿瘤细胞化学治疗的药物耐药问题是多学科、多领域的共同难题。就现在的研究来说,已发现的经典的肿瘤细胞化学治疗的耐药机制主要是膜相关糖蛋白介导的化疗药物外排机制;相关自噬凋亡DNA修复异常机制以及肿瘤细胞凋亡通路表达异常相关机制等。上皮间质转化过程(epithelial-mesenchymal transition, EMT)是肿瘤细胞在一定的生理和病理情况下,恶性肿瘤细胞由上皮细胞源性向间质细胞源性发生的转化过程。肿瘤细胞的EMT被认为是肿瘤转移和侵袭过程中的重要原因。在对发生EMT的恶性肿瘤细胞的研究过程中发现,已发生EMT的细胞, 相较于未发生EMT的细胞,细胞间黏附能力降低, 恶性肿瘤细胞的侵袭和迁移能力和抵制凋亡的能力增强, 并可引起大量恶性肿瘤细胞的细胞外基质组分的产生。研究[4]提示, 在乳腺癌、结肠癌、宫颈癌等在内多种肿瘤侵袭转移过程中均观察到EMT现象的发生。细胞的自噬是一种广泛存在于真核生物的细胞程序性死亡机制,能够在细胞生长过程中维持细胞能量的平衡并且对养分胁迫产生应答反应。近年来,TNBC治疗中自噬的研究已成为热点。其主要的研究方向分为三个方向:(1)通过抑制乳腺癌肿瘤的自我自噬保护,进而加强乳腺癌细胞的化疗药物敏感性,抑制化疗药物耐药性;(2)通过抑制乳腺癌肿瘤的自我保护性自噬,进而提高乳腺癌细胞的放疗敏感性;(3)通过促进乳腺癌细胞的自我消灭性自噬,进而直接杀伤TNBC细胞。已有学者[5-7]证实,通过激活自噬从而直接杀伤TNBC细胞, 这种激活自噬的机制可以是小分子非编码RNA(ncRna)、兴奋子(activator)和化合物(如牛樟芝Antrodia salmonea)。化疗起了不可替代的作用,但是化疗耐药一直是影响TNBC治疗的重要因素,因此抑制化疗耐药也是众多学者研究的重点。已有学者[8-11]证实抑制自噬可以增强多种化疗药物的化疗敏感性。本文就TNBC与普通乳腺癌细胞在上皮间质化和自噬性上的差异作一探索,现作报道。
三阴性乳腺癌的上皮间质转化及自噬特性差异的研究
Study on the difference between epithelial-mesenchymal transformation and autophagy in triple negative breast cancer
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摘要:
目的探讨三阴性乳腺癌(TNBC)的上皮间质转化(EMT)及自噬特性的差异。 方法选取TNBC细胞株BT-549与非TNBC细胞株MCF-7,分别对比其EMT及自噬特性。通过细胞形态,平板克隆,Transwell侵袭实验,Western blotting实验测定其EMT的差异,通过电镜观察自噬体,免疫荧光实验,Western blotting实验测定其自噬特性。 结果TNBC增殖性和侵袭性强于非TNBC,TNBC组间质细胞标志物N-cadherin、Vimentin、β-catenin相对高表达,非TNBC组上皮细胞标志物E-cadherin相对高表达。电镜下,非TNBC细胞线粒体自噬,TNBC组自噬微管相关蛋白1轻链3相对高表达。 结论TNBC增殖性、侵袭性皆强于非TNBC,EMT及自噬化程度均较高。 Abstract:ObjectiveTo explore the difference between epithelial-mesenchymal transition(EMT) and autophagy properties in triple negative breast cancer. MethodsThe epithelial-mesenchymal transition(EMT) and autophagy characteristics were compared between three negative breast cancer(TNBC) cell line BT-549 and non-triple negative breast cancer(non-TNBC) cell line MCF-7.The EMT were investigated using the cell morphology, plate cloning, transwell invasion assay and western blot analysis.The autophagy characteristics were observed by electron microscopy, immunofluorescence assay and western blot analysis. ResultsThe proliferation and invasion in TNBC were stronger than that in non-TNBC.The N-cadherin, Vimentin and β-catenin of interstitial cell markers were relatively high expression in TNBC group, and the E-cadherin of epithelial cell markers was relatively high expression in non-TNBC group.Under electron microscope, the mitochondrial autophagy was detected in non-TNBC cells, and the autophagy microtubule associated protein 1 light chain 3 was relatively high expression in TNBC group. ConclusionsThe proliferation and invasion in TNBC are stronger than that in non-TNBC, and the EMT and degree of autophagy are high in TNBC. -
Key words:
- breast cancer /
- epithelial-mesenchymal transition /
- autophagy /
- triple negative
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