EXPRESSION OF THE TYPE III INOSITOL 1, 4, 5 TRIPHOSPHATE RECEPTOR IS A NOVEL MARKER TO EVALUATE MALIGNANT POTENTIAL IN COLORECTAL CARCINOMA

InsP3受体（Ca^<2+>信号）在细胞增殖中起重要作用。肌醇1,4,5 -三磷酸受体（InsP3R）有三种异构体。在这项研究中，我们询问了InsP3R表达的每种异构体是否与临床病理未来相关。方法：采用免疫组织化学方法对19例手术切除的结直肠癌石蜡包埋标本进行InsP3R和Ki-67各亚型的检测。结果：I型和II型InsP3Rs在人结肠粘膜细胞质中均有表达，且主要表达在根尖部分。大肠黏膜未见HI型InsP3R的表达。同时，包括InsP3R型在内的所有InsP3R亚型在人类结直肠癌中均有表达。I型和II型InsP3R表达与包括细胞增殖在内的临床病理预后无关。III型InsP3R表达与肿瘤大小、肿瘤位置、疾病分期或细胞增殖无关，但与淋巴结转移有关（P=0.020）。结论：HI型InsP3R可能是潜在的结直肠癌生物标志物和预防肿瘤转移的治疗靶点。

The InsP3 receptor (Ca^<2+> signaling) is important for cell proliferation. There are three isoforms of the inositol 1, 4, 5-trisphosphate receptor (InsP3R).In this study, we asked whether each isoform of InsP3R expression is associated with the clinico-pathological futures. METHODS: In 19 paraffin embedded specimens from surgically resected colorectal carcinomas, each isoform of InsP3R and Ki-67 were evaluated by immunohistochernistry. RESULTS: Cytoplasmic expression of type I and type II InsP3Rs were observed in human colorectal mucosa mostly in their apical half. But no type HI InsP3R expression was observed in colorectal mucosa. Meanwhile, all isoforms of InsP3R including type InsP3R were expressed in human colorectal cancer. Type I and type II InsP3R expression was not correlated to clinico-pathological futures including cell proliferation. The type III InsP3R expression was not associated with tumor size, tumor location, disease stage, or cell proliferation but was related to lymph node metastasis (P=0.020). CONCLUSIONS: The type HI InsP3R may be a potential candidate of biomarker for colorectal cancer and a possible therapeutic target for preventing tumor metastasis.