Background
Long intergenic non-protein coding RNA 707 (LINC00707) has been identified as a cancer-associated long non-coding RNA (lncRNA) in a variety of cancers. However, the functions and molecular mechanisms of LINC00707 in esophageal squamous cell carcinoma (ESCC) are still unclear.
Conclusions
Our findings suggest LINC00707 functions as an oncogenic lncRNA in ESCC, and imply that LINC00707 may be a promising prognostic biomarker and therapeutic target for ESCC patients.
Methods
The expression of LINC00707 in esophageal cancer (ESCA) and ESCC tissues was determined by online tools, RNA-sequence (RNA-seq) dataset, and quantitative real time polymerase chain reaction (qRT-PCR). The associations between LINC00707 expression and clinicopathologic features and prognosis were investigated. Furthermore, the expression of LINC00707 in ESCC cell lines was determined by qRT-PCR. Then, using LncACTdb 2.0 database, combined with loss-of-function assay verification, we investigated the biologic role of LINC00707 in ESCC cell growth, apoptosis, invasion, and migration by CCK-8, colony formation, flow cytometry and transwell assays. Finally, western blot was used to evaluate the regulatory effect of LINC00707 on PI3K/Akt signaling pathway.
Results
Increased LINC00707 expression was exhibited in ESCC tissues and cell lines. High expression of LINC00707 was positively associated with higher tumor-node-metastasis (TNM) stage and lymph node metastasis. Furthermore, LINC00707 expression was significantly higher in patients who drink alcohol, have lymph node metastasis, and harbor higher tumor stage. In addition, Kaplan-Meier survival analysis and receiver operating characteristic (ROC) curve confirmed the feasibility of LINC00707 as a prognostic signature or diagnostic marker. Functional experiments showed that LINC00707 downregulation suppressed ESCC cell proliferation, and metastasis, and induced ESCC cell apoptosis. Mechanistic investigation demonstrated that LINC00707 activated the PI3K/Akt signaling pathway in ESCC cells. Conclusions: Our findings suggest LINC00707 functions as an oncogenic lncRNA in ESCC, and imply that LINC00707 may be a promising prognostic biomarker and therapeutic target for ESCC patients.