Han Su-xia, Wang Jing, Wang Li-juan, Jin Gui-hua, Ying Xia, He Chen-chen, Guo Xi-jing, Zhang Jian-ying, Zhang Ying, Zhu Qing
Department of Medical Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, People's Republic of China.
Tumour Biol. 2014 Jun;35(6):6149-57. doi: 10.1007/s13277-014-1814-3. Epub 2014 Mar 21.
Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) plays an important role in tumor progression by helping tumor cell to escape from host immunological surveillance or modifying the characteristics of connective tissue around. RCAS1 may appropriately reflect the development and prognosis of tumor. In the study, we sought to identify the clinical significance of RCAS1 in colorectal cancer (CRC) diagnosis and tumor recurrence monitoring. Immunohistochemistry (IHC) with tissue array slides was preformed to analyze RCAS1 protein expression in CRC, colorectal polyps, and normal colon tissues. RCAS1 levels in colorectal cancer were significantly higher than those in colorectal polyps and normal colon tissues (P<0.001). Silencing RCAS1 gene in human colonic adenocarcinoma cells decreased cell proliferation and enhanced apoptosis through the p53 signaling pathway. Further analysis by an enzyme-linked immunosorbent assay (ELISA) showed that serum RCAS1 levels in CRC are significantly higher than in healthy controls and polyps (P<0.05), in which the highest serum RCAS1 level is reported in the recurrence group. The serum RCAS1 levels have a significant correlation with clinical stage and pathologic grading. Furthermore, the positive rate of serum RCAS1 in CRC was 82.1 %, which was higher than carcinoembryonic antigen (CEA). Especially in CEA-negative cases, the sensitivity of RCAS1 was 88.2 %. Finally, CRC patients who were followed up showed a serum RCAS1 level which significantly decreased after surgery (P<0.001) and obviously increased in the recurrence group. Taken together, our data demonstrated that RCAS1 is not only a supplementary serological biomarker for CRC diagnosis but also useful for monitoring tumor recurrence. RCAS1 might be a supplementary serological marker for CRC.
SiSo细胞上表达的受体结合癌抗原（RCAS1）通过帮助肿瘤细胞逃避宿主免疫监视或改变周围结缔组织的特性，在肿瘤进展中发挥重要作用。RCAS1可能适当地反映肿瘤的发展和预后。在本研究中，我们试图确定RCAS1在结直肠癌（CRC）诊断和肿瘤复发监测中的临床意义。采用组织芯片玻片进行免疫组织化学（IHC）分析，以检测CRC、结直肠息肉和正常结肠组织中RCAS1蛋白的表达。结直肠癌中RCAS1水平显著高于结直肠息肉和正常结肠组织（P<0.001）。在人结肠腺癌细胞中沉默RCAS1基因可通过p53信号通路降低细胞增殖并增强细胞凋亡。通过酶联免疫吸附测定（ELISA）进一步分析表明，CRC患者血清RCAS1水平显著高于健康对照和息肉患者（P<0.05），其中复发组血清RCAS1水平最高。血清RCAS1水平与临床分期和病理分级显著相关。此外，CRC患者血清RCAS1阳性率为82.1%，高于癌胚抗原（CEA）。特别是在CEA阴性病例中，RCAS1的敏感性为88.2%。最后，对CRC患者进行随访，结果显示术后血清RCAS1水平显著下降（P<0.001），复发组明显升高。综上所述，我们的数据表明，RCAS1不仅是CRC诊断的补充血清生物标志物，而且对监测肿瘤复发也有用。RCAS1可能是CRC的补充血清标志物。
