Significance of Vesicle-Associated Membrane Protein 8 Expression in Predicting Survival in Breast Cancer

Abstract

Purpose: Vesicle-associated membrane protein 8 (VAMP8) is a soluble N-ethylmaleimide-sensitive factor receptor protein that participates in autophagy by directly regulating autophagosome membrane fusion and has been reported to be involved in tumor progression. Nevertheless, the expression and prognostic value of VAMP8 in breast cancer (BC) remain unknown. This study aimed to evaluate the clinical significance and biological function of VAMP8 in BC.

Methods: A total of 112 BC samples and 30 normal mammary gland samples were collected. The expression of VAMP8 was assessed in both BC tissues and normal mammary gland tissues via a two-step immunohistochemical detection method.

Results: The expression of VAMP8 in BC tissues was significantly higher than that in normal breast tissues. Furthermore, increased VAMP8 expression was significantly correlated with tumor size (p=0.007), lymph node metastasis (p=0.024) and recurrence (p=0.001). Patients with high VAMP8 expression had significantly lower cumulative recurrence-free survival and overall survival (p<0.001 for both) than patients with low VAMP8 expression. In multivariate logistic regression and Cox regression analyses, lymph node metastasis and VAMP8 expression were independent prognostic factors for BC.

Conclusion: VAMP8 is significantly upregulated in human BC tissues and can thus be a practical and potentially effective surrogate marker for survival in BC patients.

Keywords: Autophagy; Breast neoplasms; Prognosis; Recurrence; VAMP8 protein.

Figure 1. Immunohistochemical staining of vesicle-associated membrane protein 8 in breast cancer (BC) and normal breast tissue (×200). (A) Representative positive staining in BC. (B) Representative negative staining in BC. (C) Representative positive staining in normal breast. (D) Representative negative staining in normal breast.

Figure 2. Kaplan-Meier analysis by vesicle-associated membrane protein 8 (VAMP8) expression in 112 breast cancer patients. (A) Recurrence-free survival. (B) Overall survival.