Expression of SLP-2 gene and CCBE1 are associated with prognosis of rectal cancer.

OBJECTIVE: This study aims to investigate the clinical significance of SLP-2 gene for patients with rectal cancer. To analyze the effect of CCBE1 (Collagen and calcium-binding EGF domain-containing protein 1) on rectal cancer tissue and lymph vessels of para-carcinoma tissue.

MATERIALS AND METHODS: A total of 50 samples of rectal cancer tissues were enrolled in the experimental group, confirmed by pathological examination. 50 samples of para-carcinoma normal tissues were collected as control group. Protein expression of SLP-2 and CCBE1 was examined with immunohistochemical staining. mRNA expression of SLP-2 was examined with RT-PCR. Lymphatic vessel density (LVD) was evaluated with LYVE-1 immunohistochemical staining. Correlation analysis was performed to assess the relationship between patient survival data and clinical pathological features of rectal cancer.

RESULTS: Immunohistochemical staining showed that, compared with the control group, a positive expression rate of SLP-2 in the experimental group was significantly higher (68.0% vs. 24.0%, p<0.05), and mRNA of SLP-2 was also significantly increased (p<0.05). Compared with the control group, protein expression of CCBE1 in the experimental group was significantly higher (p<0.05). Moreover, the expression level of SLP-2 was remarkably associated with TNM classification and lymphatic metastasis. Further analysis demonstrated that a positive expression of CCBE1 was associated with lymphatic metastasis, LVD and Ducks classification, and had a negative correlation with survival rate.

CONCLUSIONS: Increased expression of SLP-2 promoted the formation of lymph vessels and exacerbated lymphatic metastasis of rectal cancer via up-regulating CCBE1. As a risk factor related to lymphatic metastasis, CCBE1 could be a novel biomarker for diagnosis and prognosis of rectal cancer.