Yonezawa S, Horinouchi M, Osako M, Kubo M, Takao S, Arimura Y, Nagata K, Tanaka S, Sakoda K, Aikou T, Sato E
Second Department of Pathology, Faculty of Medicine, Kagoshima University, Kagoshima City, Japan.
Pathol Int. 1999 Jan;49(1):45-54. doi: 10.1046/j.1440-1827.1999.00823.x.
Previously it has been found that the MUC2 gene for intestinal type secretory mucin is highly expressed in intraductal papillary mucinous tumors (IPMT), which are characterized by non-invasive growth and a favorable outcome. In contrast, MUC2 mRNA is rarely expressed in invasive ductal carcinomas (IDC), which have poor outcomes. The gastric type secretory mucin, MUC5AC, is strongly expressed in the surface mucous cells of gastric mucosa. As both MUC2 and MUC5AC mucins share the characteristics of forming highly viscous gels, it is expected that not only MUC2 mucin expression but also MUC5AC mucin expression may be associated with a favorable prognosis in patients with pancreatic tumors. MUC5AC mucin gene expression was examined in 24 cases of IPMT and 38 cases of IDC by in situ hybridization using a digoxigenin-labeled oligonucleotide. The results were compared with MUC2 mucin gene expression. Neither MUC5AC mRNA nor MUC2 mRNA was detected in normal pancreatic tissues. MUC5AC mRNA was expressed in 20 of 24 cases of IPMT (83%) and in five of 38 cases of IDC (13%). In contrast, MUC2 mRNA was expressed in 14 of 24 cases of IPMT (58%) and in none of the 38 cases of IDC (0%). The expression rates of MUC5AC mRNA and MUC2 mRNA in IPMT were significantly higher than those in IDC (P< 0.001, respectively). Intraductal papillary mucinous tumors are characterized by three histological types: (i) villous dark cell type; (ii) papillary clear cell type; and (iii) compact cell type. The villous dark cell type generally expressed both MUC5AC+ and MUC2+ genes. Alternatively, the papillary clear cell type and the compact cell type usually showed MUC5AC+ and MUC2- expression. Patients with MUC5AC mRNA expression had a significantly better survival prognosis than those with no MUC5AC mRNA expression (P< 0.005). In conclusion, MUC5AC gene expression occurs in a majority of IPMT cases, even in those with no MUC2 production. MUC5AC expression can be
此前已发现，肠道型分泌性粘蛋白的MUC2基因在导管内乳头状黏液性肿瘤（IPMT）中高度表达，该肿瘤的特征是无创性生长且预后良好。相比之下，MUC2 mRNA在预后较差的浸润性导管癌（IDC）中很少表达。胃型分泌性粘蛋白MUC5AC在胃黏膜表面黏液细胞中强烈表达。由于MUC2和MUC5AC粘蛋白都具有形成高粘性凝胶的特性，因此预计不仅MUC2粘蛋白表达，而且MUC5AC粘蛋白表达可能与胰腺肿瘤患者的良好预后相关。使用地高辛标记的寡核苷酸通过原位杂交检测了24例IPMT和38例IDC中的MUC5AC粘蛋白基因表达。将结果与MUC2粘蛋白基因表达进行比较。在正常胰腺组织中未检测到MUC5AC mRNA和MUC2 mRNA。MUC5AC mRNA在24例IPMT中的20例（83%）中表达，在38例IDC中的5例（13%）中表达。相比之下，MUC2 mRNA在24例IPMT中的14例（58%）中表达，在38例IDC中均未表达（0%）。IPMT中MUC5AC mRNA和MUC2 mRNA的表达率明显高于IDC（P分别<0.001）。导管内乳头状黏液性肿瘤有三种组织学类型：（i）绒毛状暗细胞型；（ii）乳头状透明细胞型；（iii）致密细胞型。绒毛状暗细胞型通常同时表达MUC5AC+和MUC2+基因。或者，乳头状透明细胞型和致密细胞型通常表现为MUC5AC+和MUC2-表达。MUC5AC mRNA表达的患者生存预后明显优于无MUC5AC mRNA表达的患者（P<0.005）。总之，MUC5AC基因表达在大多数IPMT病例中出现，即使在那些不产生MUC2的病例中也是如此。MUC5AC表达可以
