Objective: To screen out the protein showing most significant differential expression in colorectal cancer (CRC) tissues through proteomic technique, and then to analyze its relation with the disease profile. Methods: The surgical specimens from 83 CRC patients were collected, which included the CRC tissues, normal colonic mucosal tissues, metastatic lymph nodes and concomitant benign colonic polyps from some of the patients. Proteomics analysis that consisted of 2D differential gel electrophoresis (2D DIGE) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) was performed in CRC and normal colonic mucosa tissues. The protein of interest was validated by Western blot analysis in CRC and normal colonic mucosal tissues along with different CRC cell lines, after it was identified. The expression of this protein was also determined by immunohistochemical staining in the paraffin-embedded specimens of CRC tissue, normal mucosal tissue, benign polyp and lymph node metastasis. Western blot was performed to observe the changes of the protein expression in CRC cell lines after induction of differentiation by sodium butyrate (NaB). Results: The results of 2D DIGE analysis and MALDI-TOF-MS identification showed that the expression abundance of selenium binding protein 1 (SELENBP1) in CRC tissue was significantly decreased (2.54 folds) compared with mucosal tissue (P<0.01). Western blot analysis showed that the SELENBP1 expression level in CRC tissue was significantly lower than that in their paired normal mucosal tissue (0.76±0.37 vs. 1.46±0.56) (P<0.001), and SELENBP1 expression was generally decreased in CRC cell lines. Immunohistochemistry analysis showed that the expression scores of SELENBP1 protein in CRC and normal mucosal tissue were 1.25±0.78 and 2.02±0.77 respectively, with statistical significance (P<0.001); in well, moderately and poorly differentiated CRC tissues were 1.75±0.53, 1.29±0.41 and 0.89±0.49 respectively, with statistical significance (P<0.05); no statistical difference was found among different stages of CRC tissues, between benign polyp and normal mucosal tissue or between metastatic lymph node and primary tumor (all P>0.05). The SELENBP1 expressions in all the tested CRC cell lines were significantly increased following NaB induced differentiation (all P<0.05). Conclusion: SELENBP1 suppression is decreased in CRC tissue, and its decrease is associated with the degree of poor differentiation of CRC, but irrelevant to disease progression and lymph node metastasis.

Objective: To investigate the ADAM23 and αvβ3 expressions in colorectal cancer and their relations with liver metastases and other clinicopathologic features. Methods: The protein and mRNA expressions of ADAM23 and αvβ3 in 53 specimens of colorectal cancer and their adjacent tissue, and 20 specimens of benign disease colorectal tissue were detected by immunohistochemical staining and RT-PCR method. The relations of their protein expressions with the clinicopathologic features were analyzed. Results: The positive expression rates of both ADAM23 protein and mRNA were significantly lower in colorectal cancer tissues than those in adjacent tissues and benign disease colorectal tissues (all P<0.05), whereas the positive expression rates of both αvβ3 protein and mRNA were significantly higher in colorectal cancer tissues than those in adjacent tissues and benign disease colorectal tissues (all P<0.05). There was a negative correlation between the protein expressions of ADAM23 and αvβ3 in colorectal cancer (χ2=10.3390; r=–0.637, P<0.01). The protein expressions of ADAM23 and αvβ3 were not related with age, sex, or degree of differentiation, but significantly associated with clinical stage, lymph node metastasis and liver metastasis (all P<0.05). In addition, ADAM23 protein expression was also relevant to depth of tumor infiltration (P<0.05). Conclusion: ADAM23 expression is decreased while αvβ3 expression is increased in colorectal cancer, and both are associated with colorectal cancer liver metastases and other unfavorable clinical outcomes.

目的：观察大肠癌区域引流淋巴结中CD4+CD25+调节性T细胞（Treg）情况及其与白细胞介素10（IL-10）和转化生长因子β1（TGF-β1）水平的关系。方法：用免疫组化法检测大肠癌患者（淋巴结转移32例，无转移28例）区域引流淋巴结中CD4+CD25+的表达（Treg细胞数目）；ELISA法检测外周血血清IL-10和TGF-β1水平；分析Treg数目与IL-10和TGF-β1水平的相关性。结果：CD4+CD25+在淋巴结转移患者阳性淋巴结中呈高表达，阴性淋巴结中呈低表达，而在无转移患者淋巴结中几乎无表达；淋巴结转移患者阳性淋巴结CD4+CD25+的OD值明显高于阴性淋巴结与无转移患者淋巴结（P=0.012；P=0.002），转移患者的阴性淋巴结与无转移患者淋巴结OD值差异未达统计学意义（P=0.115）。淋巴结转移患者外周血血清IL-10，TGF-β1水平均明显高于无转移患者（P=0.003；P=0.004）。患者淋巴结CD4+CD25+的OD值与血清IL-10或TGF-β1浓度之间均呈明显正相关（r=0.683，P=0.000；r=0.532，P=0.000）。结论：大肠癌患者区域引流淋巴结中Treg细胞水平与淋巴结转移密切相关，血清IL-10或TGF-β1水平可作为监测淋巴结转移的指标。