Expressions of Lrig1 and EGFR in gastric cancer tissue

Objective To investigate the expression and clinical significance of leucine-rich repeats and immunoglobulin-like domains protein 1(Lrig1)and epidermal growth factor receptor(EGFR)in gastric cancer tissues.Methods Immunohistochemistry was used to detect the expressions of Lrig1 and EGFR protein in gastric carcinoma and normal gastric tissues from 67 patients and the correlations between the expressions and clinical pathological parameters were analyzed;the expression levels of Lrig1 and EGFR mRNA in gastric carcinoma and normal tissues from 67 patients and the expression level of Lrig1 mRNA in venous blood of 57 gastric carcinoma patients and healthy people were determined with reverse transcription polymerase chain reaction(RT-PCR).Results The positive rate of Lrig1 expression in gastric cancer tissues(35.8%, 24/67)was significantly lower than in normal tissue(91.0%, 61/67)but the positive rate of EGFR expression in gastric cancer tissues(58.2%, 39/67)was higher than in normal tissues(7.5%, 5/67), with significant differences(both P<0.05).The expressions of Lrig1 and EGFR showed no correlation with the age, sex, and the tumor size(P>0.05)but showed significantly positive correlation with the differentiation, tumour-node-metastasis(TNM)staging, and lymph node metastasis of the cancer(P<0.05).The expression level of Lrig1 mRNA in gastric carcinoma tissues(0.43± 0.16)was lower than that in normal tissues(1.06± 0.21);while the expression level of EGFR mRNA(3.27± 0.67)was higher than in normal tissues(1.33± 0.28)(P<0.05).The expression of Lrig1 and EGFR mRNA in gastric carcinoma tissues showed a significant negative correlation(r=-0.874, P<0.01).Conclusion There are a low expression of Lrig1 and a high expression of EGFR in gastric carcinoma tissues, suggesting that Lrig1 may be a cancer suppressor gene and EGFR may play an important role in the proliferation of gastric cancer cells.The expression of Lrig1 in gastric carcinoma tissue is negatively correlated with the expression of EGFR in gastric carcinoma tissue, suggesting that Lrig1 may have a feedback regulation negatively at EGFR, and they keep a certain balance in normal circumstances.