脂肪酸结合蛋白(FABP)在脂肪酸代谢中起关键作用,并以组织特异性方式表达。FABP1在肝脏中表达最丰富,约占总胞质蛋白的10%,被认为具有诊断作用。为了全面确定FABP1在正常组织和肿瘤组织中的表达,通过免疫组织化学方法分析了包含来自150种不同肿瘤类型和亚型的17,071个样本以及来自76种不同正常组织类型的608个样本的组织微阵列.在正常组织中,在肝细胞中观察到强烈的FABP1免疫染色,肾脏近端小管和小肠上皮,附录,还有结肠直肠.在150个肿瘤类别中的24个中发现FABP1阳性,包括17个肿瘤类别,至少1个强阳性病例。FABP1阳性率最高见于结直肠腺瘤(86%),在结直肠腺癌(71.1%),和肝细胞癌(65.3%),其次是卵巢粘液性癌(34.6%),胆管癌(21.6%),和消化道的各种腺癌(10-23%)。另外11个实体的阳性率在0.2%至6.5%之间。在169例原发性肺腺癌中未见到FABP1染色。在结直肠癌中,FABP1表达降低与不良等级有关,右侧肿瘤位置,微卫星不稳定性(每个p<0.0001),并且不存在BRAFV600E突变(p=0.001),但与pT和pN状态无关。FABP1表达具有相当高的肿瘤特异性。由于FABP1表达在肺腺癌中几乎不存在,FABP1免疫组织化学可能特别有助于鉴定转移性结直肠或胃肠道腺癌到肺。
Fatty acid-binding proteins (FABPs) play a pivotal role in the metabolism of fatty acids and are expressed in a tissue-specific manner. FABP1 is most abundantly expressed in the liver where it accounts for about 10% of the total cytosolic protein and is thought to have diagnostic utility. To comprehensively determine FABP1 expression in normal and neoplastic tissues, a tissue microarray containing 17,071 samples from 150 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. Among normal tissues, a strong FABP1 immunostaining was observed in hepatocytes, proximal tubuli of the kidney and epithelium of small intestine, appendix, and the colorectum. FABP1 positivity was found in 24 of 150 tumor categories, including 17 tumor categories with at least 1 strongly positive case. The highest FABP1 positivity rates were seen in colorectal adenomas (86%), in colorectal adenocarcinomas (71.1%), and in hepatocellular carcinomas (65.3%), followed by mucinous carcinoma of the ovary (34.6%), cholangiocarcinoma (21.6%), and various adenocarcinomas from the digestive tract (10-23%). Eleven additional entities had positivity rates between 0.2 and 6.5%. FABP1 staining was not seen in 169 primary adenocarcinomas of the lung. In colorectal cancer, reduced FABP1 expression was linked to poor-grade, right-sided tumor location, microsatellite instability (p < 0.0001 each), and absence of BRAF V600E mutations (p = 0.001), but unrelated to pT and pN status. FABP1 expression has considerably high tumor specificity. As FABP1 expression was virtually absent in adenocarcinomas of the lung, FABP1 immunohistochemistry might be particularly helpful to assist in the identification of metastatic colorectal or gastrointestinal adenocarcinoma to the lung.