LINC00997, a novel long noncoding RNA, contributes to metastasis via regulation of S100A11 in kidney renal clear cell carcinoma

ABSTRACT Long noncoding RNAs (lncRNAs) play an essential role in cancer development. However, the contribution of the lncRNA LINC00997 to kidney renal clear cell carcinoma (KIRC) has not been thoroughly elucidated to date. In this study, we examined the expression and biological effect of LINC00997 in KIRC development. We also investigated the potential mechanism underlying the observed effects. We found that LINC00997 is highly expressed in multiple carcinomas, being highest in stage IV KIRC in our RNA-Seq datasets. In addition, our data demonstrated that in KIRC patients, higher levels of LINC00997 are correlated with lower overall survival (OS) and disease-free survival (DFS) rates. In 18 cases of KIRC, we found that LINC00997 expression was greater in cancer tissues and metastases than in normal tissues. These results revealed that S100A11 is positively associated with LINC00997 in KIRC, which is positively correlated with metastasis-associated molecules VIM, MMP2 and MMP7. Our in vitro wound healing assay and Transwell tests demonstrated that interfering with either LINC00997 or S100A11 expression reduced migration of 786-O cells by inhibiting VIM, MMP2 and MMP7 expression. Importantly, we verified LINC00997 and STAT3 binding by RIP and determined that both LINC00997 and STAT3 bind to the S100A11 promoter, as shown by dual-luciferase reporter gene assay. In addition, inhibiting LINC00997 or STAT3 expression attenuated S100A11 levels. Consequently, the LINC00997-STAT3-S100A11 axis may promote the development of KIRC, and LINC00997 may represent a potential prognostic biomarker and therapeutic target for KIRC patients.