Expression and Significance of TRIM 28 in Squamous Carcinoma of Esophagus

Abstract

Tripartite motif-containing protein 28 (TRIM28) has been proved to accelerate cell proliferation and metastasis in a variety of human cancers. However, the role of TRIM28 in esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, to compare the biological effect and significance of TRIM28 expression in ESCC, immunohistochemistry (streptavidin-perosidase, S-P) method was used firstly to examine the expression of TRIM28 in 136 cases of ESCC, 35 cases of high grade intraepithelial neoplasia (HGIN), 29 cases of low grade intraepithelial neoplasia (LGIN) and 37 cases of normal esophageal epithelium (NEE). Then the associations of TRIM28 expression with clinicopathological data and overall survival (OS) were also analyzed. Western blot was performed to evaluate TRIM28 protein in a total of 20 matched human ESCC and NEE tissues. Moreover, the localization of TRIM28 protein in ESCC and NEE tissues was also detected by immunofluorescence. TRIM28 protein was mainly distributed in the nucleus of ESCC. The expression of TRIM28 increased progressively from NEE to LGIN, to HGIN, and to ESCC, and it was also related to invasive depth, pTNM stage and lymph node metastasis in ESCC (P < 0.05). The results of western blot and immunofluorescence all showed that the relative expression of TRIM28 protein was markedly upregulated in ESCC compared with the NEE tissues (P < 0.01). However, prognostic analysis showed that TRIM28 may not be a prognostic factor of patients with ESCC. In conclusion, the overexpression of TRIM28 may play an important role for development and metastasis in ESCC.

Keywords: Esophageal squamous cell carcinoma; Immunofluorescence; Immunohistochemistry; Overall survival; TRIM28; Western blot.

Fig. 1

Representative immunohistochemical staining of TRIM28, ×400

Fig. 2

The expression of TRIM28 in ESCC and noncancerous tissues (Chi-square and Fisher’s exact tests)

Fig. 3

Relative expression of TRIM28 protein by Western blot between paired ESCC tissues and NEE tissues (Cells in ESCC can express TRIM28 while there was no expression of TRIM28 in cells of NEE)

Fig. 4

The distribution of TRIM28 protein in ESCC and NEE tissues by immunofluorescence stainings, ×400. (TRIM28 protein was stained with green fluorescence(→), which was expressed in the nucleus in ESCC cells and nuclei were counterstained with DAPI (A); Analysis results of the fluorescence intensity (B), P = 0.000) (One-way ANOVA)