br Table br Association of CD expression
Association of CD155 expression with clinicopathological characteristics in BC patients.
Characteristics CD155 Expression
Pearson x2 P-value
Low or no High Total
H2O2. Antigen retrieval in these tissues was performed by microwave heating in 0.01 M citrate buffer (pH 6.0). CD155 was detected by polyclonal anti-human CD155 antibody (Zhongshan Golden Bridge Bio-technology, Beijing, China, dilution 1:100). We used anti-human CD155 monoclonal antibody to detect the CD155 molecule in tissues by an EnVision™ peroxidase kit (Dako, Agilent Technologies, Inc., Santa Clara, CA, USA). Then the tissues were incubated in 3,3'-diamino-benzidine (Dako, Glostrup, Denmark, Agilent Technologies, Inc.), re-stained with hematoxylin, dehydrated through gradient alcohol, cleared in xylene, and coverslipped with permanent mounting media. CD8, CD68, and CD163 (Zhongshan Golden Bridge Bio-technology, Beijing, China, dilution 1:100, 1:500, 1:500, respectively) monoclonal 70323-44-3 were used for the staining of TMAs. Reactions were detected with an Envision™ peroxidase kit (Dako, Glostrup, Denmark, Agilent Technologies, Inc.).
The CD155 expression was scored by the semi-quantitative H-score method, which considers the staining intensity and the percentage of Biomedicine & Pharmacotherapy 115 (2019) 108884
cells. The staining intensity score is indicated by numbers as follows: represents no staining, 1+ represents weak staining, 2+ represents moderate staining, and 3+ represents strong staining. Each percentage of stained cells (0˜100%) was multiplied by the corresponding intensity score to obtain the intensity percentage score, and then the final staining scores were calculated from the sum of the four intensity percentage scores. Thus, the minimum final staining score was 0, and the maximum staining score was 300.
3. Statistical analysis
The association between CD155 expression and clinicopathological characteristics was examined by x2 test. Univariate and multivariate analyses of overall survival were performed using the Cox’s regression model. The survival rates were compared by long-rank test, and the survival curves were drawn by using the Kaplan-Meier method.
4.2. CD155 expression and its association with clinicopathological characteristics
The expression level of the CD155 molecule differed among post-operative patients with BC; 103 cases showed low or no expression of CD155 and 113 cases showed high expression of CD155. As shown in Table 2, the CD155 expression level was not associated with clinical features (age and menopausal status) and partial pathological features (histology grade, and ER, PR, and HER-2 gene statuses) in BC patients. However, the CD155 expression level was significantly associated with primary tumor size, lymph node metastasis, TNM stage, Ki-67, and CD163/CD8/CD68 expression on statistical analysis, P < 0.01 (Fig. 2).
4.3. Comparison of OS rates between the CD155 low expression group and the CD155 high expression group
We used the Kaplan-Meier method to analyze the OS rates of 216 postoperative patients with BC, and then to plot the survival curves for the CD155 low or no expression and high expression groups. Then we tested the rates with the long-rank method. Finally, we concluded that the OS rate in the CD155 high expression group was lower than that in the CD155 low or no expression group (Fig. 3).
4.4. Prognostic value in human BC
We used univariate and multivariate Cox regression to analyze the possible prognostic factors in postoperative patients with BC, and they are listed in Table 3. Univariate Cox regression analysis showed that the CD155 expression level, primary tumor size, lymph node metastasis, and TNM stage were associated with the OS rate; however, age, me-nopausal status, histological type, Ki-67, and ER, PR, and HER-2 sta-tuses were not related to the OS rate. Then multivariate Cox regression analysis showed that the CD155 expression level and TNM stage were the risk factors for the OS rate. In other words, the higher the CD155 expression level and the advanced the TNM stage, the lower the OS rate. Although primary tumor size and lymph node metastasis de-termined the TNM stage, multivariate Cox regression did not suggest that these two factors were the risk factors for OS. The reason for this
occurrence might be that the sample size was not large enough.
CD155 is lowly expressed in many normal cells, such as epithelial cells, endothelial cells, nerve cells, and fibroblasts, but it is highly ex-pressed in many tumor cells. Masson D et al.  found that the CD155 gene was down-regulated in normal intestinal mucosal cells, but its expression was 2–10 times higher in colorectal cancer tissues and it continued to be highly expressed from early to late stages for the first time. Compared with colon cancer cell lines (HCT8R, SW620, and SW116), overexpression of the CD155 gene does not involve specific isomers, but it is most likely to be due to increased gene transcription. Weiling He et al.  found that CD155 is weakly expressed in normal gastric mucosal cells, but its expression is relatively high in gastric cancer tissues and gastric cancer cell lines. Nakai R et al.  detected strong expression of the CD155 molecule in bronchoalveolar carcinoma