胃癌微环境对大鼠骨髓间充质干细胞形态、生长及CD34、CD44表达的影响

Morphology and proliferation of bone marrow mesenchymal stem cells and expressions of CD34 and CD44 under stomach cancer microenvironment

背景:临床胃癌组织及裸鼠体内致瘤组织分离得到的胃癌间质干细胞(GC-MSCs),其生物学特性与骨髓间充质干细胞相似,并证明是肿瘤微环境的重要组成部分,可促进肿瘤的生长,作者推测骨髓间充质干细胞在胃癌微环境中生物学特性可能发生变化。目的:观察胃癌微环境对骨髓间充质干细胞形态、生长及CD34、CD44表达的影响。answell方法:设立骨髓间充质干细胞单独常规培养为对照组,实验组采用tr小室将人胃癌BCG-823细胞与大鼠骨髓间充质干细胞非接触共培养建立胃癌微环境,倒置相差显微镜观察骨髓间充质干细胞形态的变化、四甲基偶氮唑盐比色法(MTT法)观察骨髓间充质干细胞的增殖率、流式细胞术(FCM)检测骨髓间充质干细胞周期及表面抗原CD34、CD44的表达。结果与结论:(1)实验组骨髓间充质干细胞排列紊乱,不规则,细胞间连接疏松,细胞变细、变长,胞核变小,呈团生长,与人胃BGC-823癌细胞形态有相似之处;(2)G1期细胞比例明显降低,S期细胞比例明显增加(P<0.01)、G2/M期细胞比率显著增加(P<0.05);(3)实验组骨髓间充质干细胞的CD44阳性表达率显著降低,CD34阳性表达率显著降升高(P<0.01);(4)结果表明,将人胃癌BCG-823细胞与大鼠骨髓间充质干细胞非接触共培养模拟胃癌微环境对骨髓间充质干细胞形态、生长增殖及CD34、CD44表达有显著影响,有向胃癌细胞恶性转化的趋势。

BACKGROUND： Gastric cancer mesenchyal stem cells from clinical stomach cancer specimens and tumorigenic tissues in nude mice are similar to the bone marrow mesenchymal stem cells in biological characteristics, which have been proved to be an important component of tumor microenvironment to promote tumor growth. It is speculated that biological characteristic of bone marrow mesenchymal stem cells may change in stomach cancer microenvironment. OBJECTIVE： To observe the effect of stomach cancer microenvironment on morphology and proliferation of bone marrow mesenchymal stem cells and expressions of CD34 and CD44. METHODS： Rat bone marrow mesenchymal stem cells were cultured alone as control group. In the test group, rat bone marrow mesenchymal stem cells were co-cultured with human stomach cancer BGC-823 cells using Transwell chamber assay to establish the stomach cancer microenvironment. Then, cell morphology, proliferation, cell cycle and CD34, CD44 expressions were observed and detected using inverted phase contrast microscope, MTT assay, and flow cytometry, respectively. RESULTS AND CONCLUSION： In the test group, bone marrow mesenchymal stem cells were similar to human stomach cancer cells BGC-823 that arranged disorderly and irregularly, were interconnected loosely, became thinner and longer, and grew in clusters with smaller nuclei. The cell proportion in G1 phase significantly decreased, but that in S and G2/M phases significantly increased（P 〈0.01, P 〈0.05）. The positive rate of CD44 significantly declined, and the CD34 expression significantly raised（P 〈0.01）. In conclusion, stomach cancer microenvironment by non-contact co-culture with BCG-823 cells has an obvious effect on the morphology, proliferation and surface antigens expressions of bone marrow mesenchymal stem cells that will tend to be malignant gastric cancer cells.