LINC00565 Enhances Proliferative Ability in Endometrial Carcinoma by Downregulating KLF9

OBJECTIVE: To detect LINC00565 expression level in endometrial carcinoma (EC) samples and cell lines, and the correlations between LINC00565 and clinical features of EC patients. After intervening LINC00565, the underlying mechanism about proliferative ability in EC cell lines is observed. METHODS: Relative levels of LINC00565 and KLF9 in 52 paired EC and paracancerous tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between relative level of LINC00565 or KLF9 and clinical features of EC patients was analyzed. After knockdown of LINC00565 and KLF9, potential regulations of them on biological functions of EC were examined by Cell Counting Kit (CCK-8), colony formation assay and in vivo xenograft model in nude mice, respectively. At last, dual-luciferase reporter assay and rescue experiments were conducted to illustrate the mechanisms of LINC00565 and KLF9 in mediating the development of EC. RESULTS: LINC00565 was upregulated in EC tissues. Chi-square analysis showed that a high level of LINC00565 predicted large tumor size, advanced pathological staging and poor prognosis in EC. Silence of LINC00565 decreased proliferative ability in EC cells and tumor growth in nude mice bearing EC. KLF9 was the target gene of LINC00565. The negative interaction between LINC00565 and KLF9 was responsible for stimulating the malignant development of EC. Knockdown of KLF9 could abolish the regulatory effects of silenced LINC00565 on proliferative ability and tumorigenesis in EC. CONCLUSION: LINC00565 is upregulated in EC tissues and closely linked to tumor size, pathological staging and poor prognosis in EC patients. LINC00565 stimulates proliferative ability in EC by downregulating KLF9.