摘要
目的探讨甲基化CpG结合蛋白2（MeCP2）在胃癌组织中的表达及其对胃癌细胞多药耐药性的作用。方法采用免疫组织化学染色法检测90份胃癌组织及其相应的癌旁组织标本中的MeCP2表达情况，并分析其表达水平与临床病理参数的关系。采用Western印迹法检测MeCP2在胃癌细胞系SGC7901、胃癌耐药细胞系sGC7901／阿霉素、SGC7901／长春新碱中的表达。采用MeCP2的小干扰RNA静默MeCP2的表达后，通过MTT试验检测化学治疗药物顺铂和5-氟尿嘧啶对胃癌细胞的药物半数抑制浓度（IC50）。统计学分析采用t检验或卡方检验。结果MeCP2在胃癌组织中的表达阳性率为72．2％（65／90），显著低于相应的癌旁组织中的93．3％（84／90），差异有统计学意义（x2=14．068，P〈O．01）。MeCP2在胃癌组织中的表达与年龄、肿瘤最大径和淋巴结转移均无相关性（P均〉0．05），但与性别、临床TNM分期和远处转移相关（x2=4．680，4．186，4．327；P均〈0．05）。SGC7901／阿霉素和SGC7901／长春新碱中的MeCPB／β-actin灰度比值分别为0．5937±0．0305和0．6512±0．0186，低于其亲本细胞SGC7901的1，差异均有统计学意义（x2=23．080，17．360；P均〈0．01）。小于扰RNA静默MeCP2后，转染MecP2特异性小干扰RNA的胃癌细胞sGC7901对5-氟尿嘧啶和顺铂的IC50分别为（11．5400±0．4693）μg／mL和（2．2730±0．2654）μg／mL，分别高于转染无关序列对照寡核苷酸的胃癌细胞SGC7901对5-氟尿嘧啶和顺铂的IC50[分别为（8．6630±0．1601）μg／mL和（0．8840±0．0386）μg／mL]，差异均有统计学意义（x2=15．380，8．153；P均〈0．01）。结论MeCP2在胃癌组织中的表达显著降低，其与胃癌患者的临床分期、远处转移相关，能抑制胃癌细胞的多药耐药性，提示MeCP2的表达失调可能参与了胃癌的发生、发展。
Objective To explore the expression of methyl CpG binding protein 2 （MeCP2） in gastric cancer tissues and its role in multi-drug resistance （MDR） in gastric cancer cells. Methods The expression of MeCP2 in 90 gastric cancer tissues and the adjacent normal tissues was detected by immunohistoehemistry, and the relationship between MeCP2 expression level and clinicopathological parameters was analyzed. The expression level of MeCP2 in gastric cancer cell line SGC7901, MDR cell variants SGCf901/doxorubicin hydrochloride （ADR） and SGC7901/vincristine （VCR） was determined by Western blot. After the expression of MeCP2 was silenced by short interference RNA （siRNA）, half inhibitory concentration （ICS0） of 5-fluorouracil and cisplatin in gastric cancer cell was tested by 3-（4,5- dimethylthiazol-2-yl）-2,5-diphenyl-tetrazolium bromide（MTT） assay. The t test or chi square test was performed for statistical analysis. Results The positive rate of MeCP2 expression in gastric cancer tissues was 72.2M （65/90）, which was significantly lower than that in adjacent normal tissues （93.3%, 84/90）, and the difference was statistically significant （x2 = 14. 068, P〈0.01）. MeCP2 expression was not correlated with age, tumor maximum diameter and lymph node metastasis （all P〈0.05）, however which was related to gender, clinical TNM stages and distant metastasis （X2 = 4. 680, 4. 186 and 4. 327%all P〈 0.05）. The gray scale ratios of MeCP2/-actin in SGC7901/ADR and SGC7901/VCR were 0. 593 7 ± 0. 030 5 and 0. 651 2± 0. 018 6, which were lower than that of parental SGC7901 cells （1）, and the differences were statistically significant （t= 23. 080,17. 360% both P〈0. 01）. After the expression of MeCP2 was silenced by siRNA, the ICS0 of 5-fluorouracil and cisplatin in SGC7901 transIected with MeCP2 specific siRNA were （11. 540 0±0. 469 3） μg/mL and （2. 273 0±0. 265 4）μg/mL, which were higher than the ICS0 of 5-fluorouracil and cisplatin in SGC7901 transfected with non-related oligonucleotide sequence （（8. 663 0±0. 160 1）μg/mL and （0. 884 0 ±0. 038 6） μg/mL）, respectively. The differences were statistically significant （t= 15. 380 and 8. 153; both P〈0. 01）. Conclusions The expression of MeCP2 in gastric cancer tissues significantly decreased, which was correlated with clinical stages, distant metastasis. MeCP2 can inhibit the MDR of gastric cancer cell, which indicated the dysregulated expression of MeCP2 might participate in the genesis and development of gastric cancer.
出处
《中华消化杂志》
CAS
CSCD
北大核心
2015年第3期174-178,共5页
Chinese Journal of Digestion
基金
国家自然科学基金（81172062,81370484）
