胃癌细胞表面ALDH1 表达及ALDH1+ 细胞的“干性”鉴定

Expression of ALDH1 on surface of gastric cancer cells and identification of stem cell characteristics of ALDH1+ cells

摘要:

目的 检测胃癌细胞系的乙醛脱氢酶1（ALDH1）表达，鉴定ALDH1+ 细胞生物学特性。方法 采用 Aldefluor 实验方法，通过流式细胞仪检测胃癌细胞系MGC-803、BGC-823 及MKN-45 中ALDH1 的活性表达； 选取MGC-803 细胞系，分选出ALDH1+ 和ALDH1- 细胞，进行分化潜能、平板克隆、耐药性、干性相关基因 检测及裸鼠成瘤实验。结果 MGC-803、BGC-823 及MKN-45 中ALDH1 的表达比例为（13.00±1.34）%、（5.80± 2.15）% 及（36.5±5.4）% ；分选出ALDH1+、ALDH1- 细胞组，含血清培养1 周后，ALDH1+ 的表达比例为21.2% 和 3.9%，ALDH1+ 细胞具有不对称分裂能力；ALDH1+ 细胞组克隆形成率为（42.63±0.63）%，高于ALDH1- 细胞 组（18.5±2.04）%，两组比较差异有统计学意义（P <0.05）；相同氟尿嘧啶浓度下，ALDH1+ 组生长抑制率均 低于ALDH1- 组，差异有统计学意义（P <0.05）；接种5×103 个ALDH1+ 及ALDH1- 细胞于小鼠皮下成瘤，与 ALDH1- 细胞比较，ALDH1+ 细胞成瘤率高。两组肿瘤体积比较差异有统计学意义（P <0.05）。结论 胃癌细胞 系普遍存在ALDH1 的活性表达，ALDH1+ 细胞具有干细胞生物学特性，可能提供胃癌新的诊断和治疗途径。

Abstract:

Objective To detect the expression of ALDH1 in gastric cancer cell lines and to identify the biological characteristics of ALDH1+ cells. Methods Aldefluor assay was used to detect the expression of ALDH1 in gastric cancer cell lines MGC-803, BGC-823 and MKN-45 by flow cytometry. MGC-803 cell line was selected to isolate ALDH1+ and ALDH1- cells, then the differentiation potential, plate cloning, drug resistance, stemness genes and tumorigenicity of the cells were studied. Results The positive expression ratio of ALDH1 in MGC-803, BGC-823 and MKN-45 cells was (13.00 ± 1.34)%, (5.80 ± 2.15)% and (36.50 ± 5.40)% respectively. ALDH1+ and ALDH1- cells were sorted and cultured for 1 week, the positive expression ratio of ALDH1 was 21.2% and 3.9% respectively. The colony formation rate was (42.63 ± 0.63)% in the ALDH1+ cell group, which was significantly higher than (18.50 ± 2.04)% in the ALDH1- cell group (P < 0.05). Under the same 5-FU concentration, the growth inhibition rate of the ALDH1+ cell group was lower than that of ALDH1- cell group, the difference was statistically significant (P < 0.05). With subcutaneous inoculation of 5×103 ALDH1+ and ALDH1- cells in mice, ALDH1+ cells had a higher rate of tumor formation than ALDH1- cells, the difference of the tumor volume between the two groups was statistically significant (P < 0.05). Conclusions ALDH1 is actively expressed in gastric cancer cell lines. ALDH1+ cells have stem cell properties, which may provide a new diagnostic and therapeutic approach for gastric cancer.