基底型和HER2过表达型BCSCs裸鼠移植瘤生物学特性的比较

摘要

Objective To establish transplanted tumor model in nude mice using basal subtype and HER2 over-expressing subtype of breast cancer stem cells,and compare the biological characteristics between two subtypes.Methods Clinical breast cancer tissue samples were selected as the research object.The primary BCSCs were screened by serum free suspension culture (SFM) method.The self-renewal ability of BCSCs was evaluated by limited dilution method.Nude mice transplantation tumor experiment was applied to compare the tumor formation time,tumor volume,and tumor weight,respectively,and the growth curve was drawn.The E-cadherin,N-cadherin,MMP2 and MMP7 protein expression in xenograft tumor tissues were detected by Western blot.Results BCSCs could be effectively screened by SFM culture.The limited dilution experiment results showed that the content of BCSCs in HER2 over-expressed subtype and basal subtype breast cancer were (4.55±0.19)％ and (0.90±0.04)％,respectively.The former was 5.0 times more than the latter.The growth rate,the volumes and the weight of tumors in HER2 over-expressing subtype group were higher than the basal-like subtype (P ＜ 0.05).Western blot results slowed that the expression of mesenchymal marker N-cadherin and invasive related markers MMP2 and MMP7 were obviously up-regulated,the expression of epithelial marker E-cadherin was down-regulated (P ＜ 0.05).Conclusion The basal and HER2 over-expressing breast cancer xenografts were successfully established in nude mice.HER2 over-expressing could enhanced the in vitro self-renewal capacity BCSCs by regulating EMT,which may also applicable to the in vivo tumorigenicity and invasiveness.%目的 建立基底型及HER2过表达型乳腺癌干细胞(BCSCs)裸鼠移植瘤模型,比较两亚型BCSCs生物学特性.方法 以临床乳腺癌组织标本为研究对象,通过无血清悬浮培养筛选原代BCSCs；有限稀释法检测BCSCs自我更新能力；体内裸鼠移植瘤实验比较两亚型BCSCs成瘤时间、瘤体体积及瘤体质量,绘制生长曲线；Western blot检测肿瘤组织E-cadherin、N-cadherin、MMP2及MMP7蛋白表达.结果 无血清悬浮培养能有效筛选出BCSCs；有限稀释实验显示HER2过表达型及基底型BCSCs含量分别为(4.55±0.19)％和(0.90±0.04)％,前者是后者的5.0倍；两亚型BCSCs成瘤率均为100％；HER2过表达型移植瘤生长速率、瘤体体积和质量均高于基底型乳腺癌(P＜0.05).Western blot显示HER2过表达型乳腺癌间质样标志物N-cadherin及侵袭相关标志物MMP2、MMP7蛋白表达明显上调(P＜0.05),上皮样标志物E-cadherin蛋白表达明显下调(P＜0.05).结论 成功建立基底型及HER2过表达型乳腺癌裸鼠移植瘤模型,HER2可能通过调控EMT增强HER2过表达型BCSCs体外自我更新能力、体内致瘤性及侵袭性.