GPAA1在结直肠癌中表达增强及其意义

目的 通过检测GPAA1在结直肠癌组织中的表达以探讨其与结直肠癌增殖、侵袭、转移的关系.方法 取新鲜结直肠癌原发灶组织(52例)、正常结直肠黏膜(52例)和肝转移灶组织标本(11例)分别行免疫组织化学检测;实时定量PCR检测每个组织样本中GPAA1基因表达水平;高表达GPAA1 mRNA结直肠癌组织和低表达GPAA1 mRNA结直肠癌组织行原代细胞培养,将培养获得的原代细胞进行Boyden小室体外增殖、侵袭实验.结果 52例结直肠癌患者标本经免疫组织化学检测,GPAA1在结直肠正常肠黏膜、癌原发灶、肝转移灶中的表达阳性率分别为21.15% ( 11/52)、55.76% (29 /52)、和72.73% ( 8/11).GPAA1在结直肠癌原发灶、肝转移灶中表达阳性率均高于正常肠黏膜组织(P＜0.01).通过实时定量PCR检测发现GPAA1 mRNA表达水平在结直肠癌原发灶、肝转移灶中均高于结直肠正常肠黏膜(P＜0.01);在肝转移灶中的GPAA1 mRNA水平高于癌原发灶(P＜0.05);高表达GPAA1 mRNA的原代细胞穿透Matrigel微孔滤膜细胞数明显高于低表达GPAA1 mRNA组.结直肠癌组织中GPAA1 mRNA的表达水平与组织分化程度相关,而与年龄、性别及Dukes分期无明显相关,(P<0.05).结论 GPAA1表达增强与结直肠癌的发生、侵袭、转移有密切关系.

Increased expression of GPAA1 and its significance in colorectal cancers

Objective To detect the expression of glycosylphosphatidylinositol anchor attachment protein 1(GPAA1)in colorectal carcinoma tissues and to study the relationship between the expression of GPAA1 and the proliferation, invasion, metastasis of colorectal cancers. Methods Immunohistochemistry was used to detect GPAA1 in tissues and the mRNA level of GPAA1 was quantified by real-time quantitative PCR in normal colorectal mucosa, primary cancer and liver metastasis foci, respectively. Primary culture of cancer cells was carried out in vitro in all groups, including the higher GPAA1 expression group and the lower GPAA1 expression group. The cultured cells were tested by cell invasion assay. Results The expression rate in normal colorectal mucosa, primary cancer, liver metastasis foci were 21.15%( 11/52), 55.76%(29 /52), 72.73% ( 8/11) respectively. The positive rate of GPAA1 in primary cancer and liver metastasis foci was significantly higher than that in normal mucosa (P<0.01). GPAA1 mRNA level was significantly higher in primary cancer and liver metastasis foci than in normal mucosa (P<0.01). The -difference in expression between primary cancer and liver metastasis foci was statistically significant (P<0.05). High GPAA1 level was associated with poor differentiation of colorectal carcinoma. However, GPAA1 level was not correlated with other clinical or pathological features including age, sex, and pTNM staging. Conclusions Increased expression of GPAA1 is associated with the proliferation, invasion, metastasis of colorectal carcinoma.