Oncogenic Function Of Mir-301 To Predicts Poor Prognosis Of Endometrial Cancer

Background: Endometrial cancer (EC) is a common female malignancy, and dysregulation of microRNAs (miRNAs) is associated with malignant transformation. The present study aimed to identify new molecular markers for predicting the outcomes of EC patients. Methods: Microarray analysis was used to analyze the difference in the expression level of miRNAs between the primary cancer tissue and proliferative endometrium. qRT-PCR was employed to measure the expression level of miR-301 in clinical EC tissues and proliferative endometrium. Survival curves were constructed using the Kaplan-Meier method, and a log rank test was used to assess the differences between clinicopathological characteristics and survival in EC patients. Results: Ten miRNAs showed the highest significant difference after independent examination using qRT-PCR, with 8 up-regulated (miR-21, miR-196a, miR16, miR-582-5p, miR-15b, miR-301, miR-148b, and miR-128a) and 2 down-regulated (miR-125 and miR-34). As the most highly up-regulated miRNA, miR-301 was further examined. The expression level of miR-301 in EC tissues was significantly higher than that in the proliferative endometrium (1.03 +/- 0.18 vs. 3.21 +/- 0.76, P< 0.0001). The median fold change of miR-301 was used as a cutoff value. High miR-301 expression was observed to be closely correlated with lymph node metastasis (P = 0.073), distant metastasis (P = 0.038), myometrial invasion (P = 0.033), grade (P = 0.007), advanced TNM stage (P = 0.000) and vessel invasiveness (P = 0.026). The 5-year overall survival rate in the high expression group was 45.8%, compared with 69.8% in the low expression group (P = 0.025). Conclusion: Our findings provide convincing evidence that the up-regulation of miR-301 may serve as a novel molecular marker to predict aggressive tumor progression and an unfavorable prognosis in EC patients.