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

InsP 3受体（Ca^2+信号传导）对于细胞增殖是重要的。三磷酸肌醇受体（InsP 3R）有三种亚型，本研究旨在探讨InsP 3R各亚型的表达是否与临床病理特征相关。方法：对19例结直肠癌手术切除石蜡包埋标本进行InsP 3R和Ki-67的检测。结果：I型和II型InsP 3Rs在人结直肠粘膜中均呈胞浆表达，主要表达部位为顶侧。而HI型InsP 3R在结直肠粘膜中无表达。InsP 3R在大肠癌组织中的表达与其亚型有关。I型和II型InsP 3R表达与临床病理学未来（包括细胞增殖）无关。III型InsP 3 R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InsP 3R可能是结直肠癌生物标志物的潜在候选者，并可能成为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.