Abnormal expression of early growth response 1 in gastric cancer: Association with tumor invasion, metastasis and heparanase transcription

Given that previous studies indicated that early growth response 1 (EGR1) exerts pro-tumorigenic effects through regulating heparanase (HPA) transcription, it was hypothesized that EGR1 may correlate with the progression of gastric cancer. One hundred and fifteen patients with gastric cancer were evaluated for the protein and transcript expression of EGR1 and HPA on immunohistochemistry and real-time quantitative polymerase chain reaction (PCR). In normal gastric mucosa, EGR1 protein expression was absent or weak, whereas gastric cancer was positive for EGR1. Seventy gastric cancer patients (60.9%) were positive for cytoplasmic EGR1 expression, and 26 (22.6%) had nuclear expression of EGR1. In the gastric cancer examined, the transcripts of EGR1 were enhanced compared to that of normal gastric mucosa, and positively correlated with EGR1 protein expression. The cytoplasmic or nuclear expression of EGR1 and its transcripts in gastric cancer was positively correlated with tumor infiltration (P < 0.05), lymph node and distant metastasis (P < 0.05), tumor node metastasis (TNM) stages (P < 0.05), but not with age, gender, tumor location and size, histological types or differentiation. Moreover, the protein and transcript expression of EGR1 was correlated with that of HPA in gastric cancer. These results indicate that aberrant expression of EGR1 in gastric cancer is associated with tumor invasion and metastasis, and HPA transcription.