Silencing of UCA1, a poor prognostic factor, inhibited the migration of endometrial cancer cell

Endometrial cancer (EC) is a common female malignancy. Most patients were diagnosed at an early stage with a favorable prognosis. But more than 30% patients were high risk at III/IV stage with invading deep into the myometrium and progressively lead to local or extra pelvic metastasis. Urothelial cancer-associated 1 (UCA1) had been reported as the oncogenic long non-coding RNA in many tumors, but the role of UCA1 in EC is still unclear.

QRT-PCR was used to analysis the level of UCA1 in the proliferative endometrium, primary EC tissue and lymph node metastasis tissue of EC. According to the QRT-PCR results of primary EC tissue, survival curves were made using the Kaplan-Meier method, and the log rank test was used to analyze the differences of clinicopathological characteristics and survival between the low expression and high expression group of UCA1 in EC patients. Moreover we knocked down the expression of UCA1 in EC cell lines HTB-111 and Ishikawa, and detected the migration and invasion ability of them with wound healing assay and transwell assay.

The expression level of UCA1 using QRT-PCR method in lymph node metastasis tissue was the highest than that in the proliferative endometrium and primary EC tissues (1.15 ± 0.23, 3.23 ± 1.06 vs. 6.42 ± 1.46, P < 0.0001). For the primary EC tissue, the median fold change of UCA1 was used as a cutoff value. High UCA1 expression was observed to be closely correlated with lymph node metastasis (P = 0.008), distant metastasis (P = 0.003), grade (P = 0.009), advanced TNM stage (P = 0.031) and vessel invasive (P = 0.032). The 5-year overall survival rate in the high expression group was 41.7%, compared with 72.7% in the low expression group (P = 0.023). After silencing the UCA1, the migration and invasion ability of EC cell lines reduced significantly.

Our findings provide the convincing evidence that the UCA1 plays an important role in the metastasis of EC and may serve as a novel molecular marker to predict the aggressive tumor progression and unfavorable prognosis of EC patients.