Downregulation of lncRNA LINC-PINT Participates in the Recurrence of Esophageal Squamous Cell Carcinoma Possibly by Interacting miRNA-21

Backgrounds: LncRNA long intergenic non-protein coding RNA, p53 induced transcript (LINC-PINT) is downregulated in multiple types of cancer cells. The authors aimed to explore the possible involvement of LINC-PINT in esophageal squamous cell carcinoma (ESCC). Materials and Methods: Sixty-two patients with early-stage ESCC were included in this study. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect gene expression in plasma from ESCC patients and healthy controls. Diagnostic analysis was performed by receiver operating characteristic (ROC) curve. Transfections were performed to analyze gene interactions. Cell invasion and migration were analyzed by Transwell assays. Results: Plasma LINC-PINT was downregulated and microRNA (miRNA)-21 was upregulated in early-stage ESCC patients. Diagnostic analysis by ROC curve revealed that downregulation of lncRNA LINC-PINT distinguished ESCC patients from healthy controls. Plasma levels of LINC-PINT and miRNA-21 were negatively correlated in ESCC patients. After surgical resection, only local recurrence was observed during 3-years follow-up. LINC-PINT expression was further downregulated in recurrent patients but not in nonrecurrent patients. ROC curve analysis revealed that plasma levels of LINC-PINT at 12 months before recurrence can be used to distinguish ESCC patients from healthy controls. Overexpression of LINC-PINT could inhibit the expression of miRNA-21 in human ESCC cells, whereas LINC-PINT expression was not altered by miR-21 overexpression. Conclusion: Therefore, downregulation of LINC-PINT participated in the recurrence of ESCC possibly by interacting with miRNA-21.