肺癌细胞系中肿瘤干细胞的分离鉴定与功能分析

Isolation and identification of cancer stem cells in lung cancer cell lines as well as function analysis

背景:肿瘤干细胞在体外扩增和培养过程中如何保持其干细胞的特性成为肿瘤干细胞研究的重要障碍,从可长期稳定保存的细胞系中分离获得肿瘤干细胞可能成为肿瘤干细胞研究的可靠途径。目的:探讨遗传背景相似、转移特性不同的肺癌细胞中肿瘤干细胞的存在与否及其功能。方法:观察PLA-801D和PLA-801C细胞对鼠尾胶原和纤连蛋白的黏附作用,以考察两株细胞的转移潜能;观察PLA-801D和PLA-801C细胞形成单细胞克隆的种类及每种细胞克隆的亚克隆种类和性能,判断两株细胞中是否存在肿瘤干细胞;采用胶原收缩实验考察两株细胞的生物力学重塑能力,即对细胞外基质的重塑能力。结果与结论:PLA-801D细胞对鼠尾胶原和纤连蛋白的黏附作用均明显强于PLA-801C细胞(P<0.01)。PLA-801D可产生4种单细胞克隆,其中1种在传单细胞亚克隆后仍可形成如上4种克隆,而PLA-801C细胞中未发现有完全分化能力的细胞克隆。PLA-801D细胞的生物力学重塑能力也明显高于PLA-801C细胞(P<0.05)。结果证实具有高转移潜能的PLA-801D细胞中含有一小群具有自我更新和分化能力的肿瘤干细胞,且该细胞株的生物力学重塑性较好,提示该细胞株对细胞外基质的重塑性能较强。

BACKGROUND：It is difficult to maintain the ＂stem cell＂ characteristics of cancer stem cells in vitro during proliferation and culture. To obtain cancer stem cells from cancer cell lines that can be kept for a long time is a reliable means. OBJECTIVE：To investigate whether cancer stem cells exist or not in lung cancer cell strains with similar genetic background and different metastasis potential and function thereof. METHODS：The adhesion assays on rat collagen or fibronectin were used to assess the metastasis potential of PLA-801D and PLA-801C. The existence of cancer stem cells in the two cell strains was demonstrated with the differentiation potency of their single cell colons and subclones. The biomechanical remodeling potential of the two cell strains was evaluated with collagen gel contraction assays. RESULTS AND CONCLUSION：Compared with PLA-801C cells,PLA-801D cells showed significantly stronger adhesion on both rat collagen and fibronectin （P 0.01）. PLA-801D cells could form four kinds of single cell clones,and one of them could differentiate into the same four clones in subclones. However,only three kinds of clones were found in PLA801C cells,and none of them could differentiate into the initial three clones in their subclones. PLA-801D cells showed better collagen gel contraction than PLA-801C cells （P 0.05）. These results indicate that a grouplet of cells in PLA-801D cells show self-renewal and multi-directional differentiation characteristic of cancer stem cells. Moreover,PLA-801D cells display good biomechanical remodeling potential,indicating its good remodeling capacity for extracellular matrix.