Kobayashi M, Watanabe H, Ajioka Y, Honma T, Asakura H
First Department of Pathology, Niigata University School of Medicine, Japan.
Hum Pathol. 1996 Oct;27(10):1042-9. doi: 10.1016/s0046-8177(96)90281-6.
The authors evaluated the association of the K-ras mutation with the distribution of proliferating cells and the macroscopic appearance of colorectal tumors. A total of 122 colorectal adenomas and 96 early cancers were classified macroscopically as follows: (1) polypoid, exceeding 3 mm in height; (2) flat or hemispherically elevated 3 mm or less; and (3) depressed. The intramucosal areas of these tumors were examined by Ki-67 immunostaining and nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to detect proliferating cells and the K-ras codon 12 mutation. The distribution pattern of the Ki-67-positive cells was of two types: diffuse (D), being positive throughout the crypts, and superficial (S), being positive mainly in the superficial areas of the crypts. The K-ras mutation and the D type distribution of the Ki-67-positive cells were significantly less common (P < .005) in the nonpolypoid, depressed, or elevated tumors versus the polypoid tumors. The incidence of the K-ras mutation was significantly (P < .0001) associated with the D type distribution. The K-ras mutation may involve a disorder of cell proliferation that leads to the polypoid growth of colorectal tumors.
作者评估了K-ras突变与结直肠肿瘤增殖细胞分布及大体外观之间的关联。总共122例结直肠腺瘤和96例早期癌按大体形态分为以下几类：(1)息肉样，高度超过3 mm；(2)扁平或半球形隆起且高度在3 mm及以下；(3)凹陷型。通过Ki-67免疫染色和巢式聚合酶链反应-限制性片段长度多态性(PCR-RFLP)检测这些肿瘤的黏膜内区域，以检测增殖细胞和K-ras密码子12突变。Ki-67阳性细胞的分布模式有两种：弥漫型(D)，隐窝全程呈阳性；浅表型(S)，主要在隐窝浅表区域呈阳性。与息肉样肿瘤相比，非息肉样、凹陷型或隆起型肿瘤中K-ras突变和Ki-67阳性细胞的D型分布明显较少见(P < 0.005)。K-ras突变的发生率与D型分布显著相关(P < 0.0001)。K-ras突变可能涉及细胞增殖紊乱，从而导致结直肠肿瘤呈息肉样生长。
