Oncogenic role of clusterin overexpression in multistage colorectal tumorigenesis and progression

Figure 1 Expression of clusterin in different pathological loci of one Dukes C colorectal carcinoma with matched lymph node metastasis. Strong cytoplasmic staining of clusterin was observed in primary carcinoma in the mucosa layer of the bowel wall, while its adjacent normal mucosa showed a weak positivity (A). Strong cytoplasmic staining of clusterin was also observed in carcinomas in muscularis propria (B), and serosa layer (C) and its matched lymph node metastasis (D) in the same primary carcinoma (original magnification ×100).

Figure 2 Double fluorescent staining of clusterin and TUNEL in colorectal carcinoma. A: A colorectal carcinoma with overexpression of cytoplasmic clusterin (red) showed low apoptotic index (AI), where apoptosis (green signal indicated with arrows) was observed in only one tumor cell; B: High AI was observed in a CRC with negative expression of cytoplasmic clusterin, where several TUNEL positive cells (green nuclei indicated with arrows) were observed. (Left figure: original magnification ×100; Right figure: ×400).