Predictive value of LncRNA LINC00667 in the development and prognosis of papillary thyroid carcinoma and its possible regulation of cellular processes via miR-34c-5p.

[BACKGROUND] As a major type of endocrine malignancy, thyroid cancer (THCA) has a relatively high occurrence rate around the world. However, the underlying mechanism through which LINC00667 acts in papillary thyroid carcinoma (PTC) remains unelucidated.

[METHODS] A total of 120 PTC patients were enrolled. The expression of LINC00667 was analyzed using reverse transcription-quantitative polymerase chain reaction. To evaluate the clinical significance of LINC00667, chi-square analysis was performed, a Kaplan-Meier survival curve was generated, and multivariate Cox analysis was conducted to determine its association with the clinical-pathological characteristics and prognostic outcomes of PTC. Cell Counting Kit-8 and Transwell assays evaluated changes in cellular processes. A dual luciferase reporter assay and RNA Immunoprecipitation were employed to analyze the binding relationship between LINC00667 and miR-34c-5p.

[RESULTS] LINC00667 exhibited significant up-regulation in PTC tissues, with elevated expression levels associated with tumor malignancy. Increased LINC00667 expression was a marker of unfavorable prognostic outcomes and functioned as an independent risk indicator for PTC. Knockdown of LINC00667 expression inhibited the proliferation, migration capability, and invasive properties of PTC cells. Furthermore, LINC00667 was identified to exert a negative regulatory effect on miR-34c-5p, and the silencing of miR-34c-5p weakened the inhibitory impacts induced by LINC00667 depletion on the malignant behaviors of PTC cells.

[CONCLUSIONS] Up-regulated LINC00667 may serve as a biomarker for PTC. Knockdown of LINC00667 may inhibit the progression of PTC by regulating miR-34c-5p.