Abstract:

Objective To investigate the expression of amyloid precursor-like protein 2 (APLP2) in tissues of endometrial cancer and analyze the correlation between the expression of APLP2 and relevant clinical indexes. Methods RNA-SEQ data of 335 cases of endometrial cancer in the Cancer Genome Atlas (TCGA) database was analyzed by data mining. The correlation between the expression of APLP2 and the survival of patients with endometrial cancer was analyzed by Kaplan-Meier method based on RNA-SEQ data and complete survival information of patients. The mRNA expression of APLP2 in 30 frozen tissues of normal endometrium and 30 frozen tissues of endometrial cancer was detected by real-time PCR. The protein expression of APLP2 in 32 tissues of normal endometrium and 88 tissues of endometrial cancer was detected by immunohistochemical method. Results Analysis of Kaplan-Meier survival curve showed that the overall survival of patients with low expression of APLP2 significantly decreased (HR=2.87, P=0.002). Results of real-time PCR indicated that mRNA expressions of APLP2 in tissues of endometrial cancer were significantly lower than those in tissues of normal endometrium (P=0.031). Results of immunohistochemical method showed that the positive expression rate of APLP2 in tissues of endometrial cancer was significantly lower than that of in tissues of normal endometrium (P=0.025) and the expression level of APLP2 was correlated with the expression level of estrogen receptor (P=0.010). Conclusion APLP2 plays the role of tumor-suppressor gene for patients with endometrial cancer. APLP2 genes may take effect via the estrogen receptor and may be a target for the treatment and predicting the prognosis of patients with endometrial cancer.

Key words: amyloid precursor-like protein 2, endometrial cancer, data mining, real-time quantitative PCR, immunohistochemistry