Overexpression of periostin is significantly correlated to the tumor angiogenesis and poor prognosis in patients with esophageal squamous cell carcinoma

Abstract

Recent studies have found that periostin (PN), as a kind of secreted glycoprotein, is closely related to the metastatic potential and prognosis of many kinds of tumors. This study aimed to examine the expression of PN in patients with esophageal squamous cell carcinoma (ESCC) and explore the relationship of PN expression with clinicopathologic factors, tumor angiogenesis and prognosis. The results showed that increased PN protein expression was prevalent in ESCC and was significantly associated with lymphatic metastasis (P=0.008), tumor differentiation (P=0.04), venous invasion (P=0.014) and TNM stage (P=0.001). Additionally, expression of PN was found to be an independent prognostic factor in ESCC patients. High expression of PN protein is closely correlated to the tumor progression and angiogenesis and poor survival of ESCC. Taken together, PN is a promising biomarker to identify individuals with poor prognostic potential and concludes the possibility of its use as a prognostic marker in patients with ESCC.

Keywords: Periostin; angiogenesis; esophageal squamous cell carcinoma; prognosis.

Figure 1

Immunohistochemical staining of periostin, VEGF and CD31 in esophageal squamous cell carcinoma (ESCC) tissues. Periostin (PN) mainly expressed in the cytoplasm of ESCC tissues. A: ++ PN staining; B: + PN staining; C: Negative for PN staining; D: ++ PN staining; E: Positive for VEGF staining; F: Positive for CD31 staining. A-C: Bar=100 μm; D-F: Bar=50 μm, examined by using serial sections.

Figure 2

Intratumoral microvessel density (MVD) in relation to periostin (PN) protein immunoreactivity. Mann-Whitney U test demonstrated that tumors with PN-positive expression showed significantly higher intratumoral MVD than that with PN-negative expression (P=0.000).

Figure 3

Western blot analysis of periostin (PN, 90 kDa) and VEGF proteins in two fresh frozen esophageal squamous cell carcinoma (ESCC) and corresponding paracarcinomatous normal tissues. T: ESCC tissues; N: corresponding paracarcinomatous normal tissues.

Figure 4

Kaplan-Meier analysis of overall survival (OS) and disease-free survival (DFS) curves of patients with esophageal squamous cell carcinoma (ESCC) based on periostin expression as positive or negative. A: OS curve of patients with ESCC based on periostin expression; B: DFS curve of patients with ESCC based on periostin expression. The ESCC patients with periostin positive showed significantly poorer OS and DFS rates than those with periostin negative.

Figure 5

Kaplan-Meier analysis of overall survival (OS) and disease-free survival (DFS) curves of patients with esophageal squamous cell carcinoma (ESCC) based on periostin expression as strongly positive, weakly positive or negative. A: OS curve of patients with ESCC based on periostin expression; B: DFS curve of patients with ESCC based on periostin expression. The ESCC patients with periostin positive showed significantly poorer OS and DFS rates than those with periostin negative. The survival of patients in the strongly positive periostin expression was poorest.