Background and objective: Recent studies indicate that the side population (SP) which is an enriched source of cancer stem cells (CSCs) is the root cause of tumor growth and development. SP appears to be highly resistant to chemo- and radio-therapy which becomes an important factor in tumor recurrence and metastasis. The aim of this study is to determine the difference of microRNA expression profiles between SP cells and non-SP cells so as to lay necessary basis for research on the function of miRNA in lung cancer stem cells.
Methods: SP and non-SP cells were isolated using flow cytometry and Hoechst 33342 dye efflux assay from human lung adenocarcinoma A549 cell. The total RNA was extracted. The microarray detection system was employed to analyze whether there was difference in miRNA expression profile between SP and non-SP cells.
Results: A total of 85 differentially expressed miRNA were found, including 32 over-expression and 53 low-expression miRNA in SP.
Conclusions: miRNA may play important roles in tumorigenesis of lung cancer stem cell. The study of miRNA contributes to elucidate the molecular mechanism of lung cancer stem cell.
背景与目的: 目前研究认为侧群细胞（side population cell, SP cell）富集了肿瘤干细胞，是肿瘤生长和发展的根源；并且SP细胞对放化疗高度耐受，成为肿瘤复发转移的重要因素。为此，我们探讨了肺癌SP细胞与非SP细胞（non-SP）miRNA分子表达谱差异，旨在为进一步研究miRNA在肺癌干细胞中的作用机制打下基础。
方法: 利用Hoechst 33342染料法，通过流式细胞仪紫外激光分选功能分选出A549细胞中的SP细胞和non-SP细胞，分别采用Trizol一步法提取两者的总RNA，利用miRNA芯片检测系统进行miRNA表达谱差异分析。
结果: 肺癌SP细胞和non-SP细胞miRNA表达谱存在明显差异。与non-SP细胞相比，在SP细胞中上调2倍以上的miRNA有9条，下调2倍以上的miRNA有25条。
结论: 差异表达的miRNA可能参与肺癌干细胞的发生发展过程，为进一步揭示肺癌干细胞发生的分子机制提供了依据。