Expression of cystatin A in esophageal squamous cell carcinoma and its clinical significance

Abstract

Objective To investigate the expression and clinical significance of cysteine protease inhibitor A(CSTA) in esophageal squamous cell carcinoma. Methods A total of 59 patients with esophageal cancer who underwent esophagectomy or endoscopic submucosal tumor dissection were enrolled. The esophageal squamous cell carcinoma and normal esophageal tissues were collected and clinical pathological data were collected. The expression of CSTA mRNA and protein in cancer tissues and normal tissues was determined by real-time quantitative fluorescent polymerase chain reaction (RTFQ-PCR) and immunohistochemistry. The expressions of CSTA and Ki-67 mRNA and protein in cancer tissues and normal tissues were determined by RTFQ-PCR and Western Blot. Results Compared with normal, the expression of CSTA mRNA and protein in esophageal squamous cell carcinoma tissues was significantly lower, and the difference was statistically significant (all P<0.05). In squamous cell carcinoma, the CSTA-positive expression is often associated with Ki-67 expression, whereas normal esophageal tissue has CSTA expression but no Ki-67 expression. Squamous cell carcinoma with CSTA-positive expression had higher tumor pT stage and tumor grade (all P<0.05). Conclusions The expression of CSTA in cancer tissues of patients with esophageal squamous cell carcinoma is significantly lower than that in normal tissues. The CSTA-positive expression in esophageal squamous cell carcinoma is related to the pT clasification and tumor grade. The CSTA test for esophageal squamous cell carcinoma can provide a basis for clinical treatment. Key words: Esophageal squamous cell carcinoma; Cysteine protease inhibitor A; Ki-67