肿瘤干细胞表面标记物CD44在胃癌浸润和淋巴结转移中的作用

Effects of cancer stem cell surface marker CD44 in gastric cancer invasion and lymph node metastasis

背景:肿瘤干细胞不仅能启动肿瘤发生,还参与肿瘤细胞的侵袭和转移。对肿瘤干细胞来说,识别其特异性细胞表面标志物已成为研究热点。目的:探讨肿瘤干细胞表面标记物CD44在胃癌浸润和淋巴结转移中的临床意义。方法:采用免疫组化SABC法检测胃癌组织标本CD44蛋白表达,应用Pearsonχ2检验和Cox回归多因素分析,确定CD44表达与胃癌生物学特性及其预后的相关性。结果与结论:100例胃癌标本中,59例(59.0%)标本CD44蛋白呈阳性表达。CD44蛋白在距胃癌原发灶边缘5 cm以上的正常胃黏膜组织中呈阴性表达。胃癌组织中CD44蛋白广泛表达,主要表达于细胞膜,少量表达于细胞浆。胃癌组织中CD44蛋白的表达和患者性别、年龄无关(P>0.05),但与肿瘤分期和淋巴管浸润、组织学分级、肿瘤大小等有关(P<0.05),其中,肿瘤浸润越深、组织学分级越高、肿瘤直径越大、有淋巴结转移,则CD44蛋白表达阳性率越高,CD44阳性表达是影响患者术后生存的独立预后因素(P<0.05)。以上结果表明肿瘤干细胞表面标记物CD44在胃癌组织中的表达与胃癌的浸润和淋巴结转移密切相关,表达越高患者预后越差。

BACKGROUND： Tumor stem cells not only initiate tumorigenesis, but also are involved in the invasion and metastasis of tumor cells. For tumor stem cells, to identify the specific cell surface marker has become a research hotspot.OBJECTIVE： To explore the clinical significance of cancer stem cell surface marker CD44 in gastric cancer invasion and lymph node metastasis.METHODS： CD44 protein expression in specimens of gastric cancer tissue was detected by the immunohistochemical SABC method. The relationship between CD44 protein expression and biological characteristics and prognosis of gastric cancer was detected using Pearson χ2 test and Cox regression analysis.RESULTS AND CONCLUSION： Among 100 cases of gastric carcinoma, 59 cases（59%） were positive for CD44 protein expression. CD44 protein expression in normal gastric mucosa at above 5 cm from the edge of primary gastric cancer was negative. CD44 protein was widely expressed in tissues of gastric cancer, mainly expressed in the cell membrane, and a small amount of expression in the cytoplasm. CD44 protein expression in gastric cancer tissue was not correlated with sex of the patients or age（P〉0.05）, but was associated with tumor staging and lymph duct tissue infiltration, histological grade, and tumor size（P〈0.05）. Deep tumor invasion, high histological grade, big diameter of tumor, and lymph node metastasis could lead to high positive CD44 protein expression. Positive expression of CD44 is an independent prognostic factor affecting postoperative survival（P〈0.05）. The results show that the cancer stem cell surface markers CD44 in gastric carcinoma tissues is strongly associated with invasion of gastric carcinoma and lymph node metastasis. High expression of CD44 presents poor prognosis.