Shi Xueying, Gong Encong, Wu Xiaopan
Department of Pathology, School of basic Medical Sciences, Peking University, Beijing, China.
Appl Immunohistochem Mol Morphol. 2007 Jun;15(2):175-80. doi: 10.1097/01.pai.0000213107.20355.d8.
Alpha-methylacyl-CoA racemase (AMACR)/P504S is an enzyme involved in the metabolism of branched-chain fatty acids. Little is known about correlation of AMACR expression with colorectal carcinoma (CRC) differentiation and prognosis. We investigated the expression of AMACR in 106 cases of primary CRC, and in 47 lymph nodes with metastatic CRC by immunohistochemical analysis. These cases were divided into 3 groups according to the histologic differentiation of the primary tumors. group A included 50 cases of histologically well and moderately differentiated CRCs, 20 of these with lymph node metastasis; group B included 23 cases of well and moderately differentiated CRCs, histologically similar to group A, except these tumors had small foci (less than 20%) of high-grade carcinoma, and 10 of these had lymph node metastasis; group C included 33 cases of poorly differentiated adenocarcinoma and undifferentiated carcinoma, 17 with lymph node metastasis. The results showed the overall positive rates of expression in primary and metastatic CRCs were 59.4% and 46.8%, respectively. Expression in groups A (76.0%) and B (69.6%) was much higher than that in group C (27.3%). In group B, although overexpression of AMACR in primary tumors was similar to that of group A, it was only seen in 30.0% of group B metastatic tumors, which was similar to the rate of expression in group C (23.5%). In contrast, rates of expression in group A primary and metastatic tumors were similar (80.0% and 75.0%). Positive staining for AMACR in benign epithelium adjacent to tumor was rare (<2%). No relation was found between AMACR expression and overall survival. Our findings support the view that the expression of AMACR in CRC is correlated with tumor differentiation.
α-甲基酰基辅酶A消旋酶（AMACR）/P504S是一种参与支链脂肪酸代谢的酶。关于AMACR表达与结直肠癌（CRC）分化及预后的相关性知之甚少。我们通过免疫组化分析研究了106例原发性CRC及47例伴有CRC转移的淋巴结中AMACR的表达情况。根据原发性肿瘤的组织学分化情况将这些病例分为3组。A组包括50例组织学上高分化和中分化的CRC，其中20例伴有淋巴结转移；B组包括23例高分化和中分化的CRC，组织学与A组相似，但这些肿瘤有小灶性（小于20%）高级别癌，其中10例伴有淋巴结转移；C组包括33例低分化腺癌和未分化癌，17例伴有淋巴结转移。结果显示，原发性和转移性CRC中AMACR的总体阳性表达率分别为59.4%和46.8%。A组（76.0%）和B组（69.6%）中的表达远高于C组（27.3%）。在B组中，虽然原发性肿瘤中AMACR的过表达与A组相似，但仅在30.0%的B组转移瘤中可见，这与C组的表达率（23.5%）相似。相比之下，A组原发性和转移性肿瘤中的表达率相似（80.0%和75.0%）。肿瘤旁良性上皮中AMACR的阳性染色罕见（<2%）。未发现AMACR表达与总生存期之间存在关联。我们的研究结果支持以下观点，即CRC中AMACR的表达与肿瘤分化相关。
