Clinical Relevance and Regulatory Mechanisms of LINC01521 in Papillary Thyroid Carcinoma

ABSTRACT Objective Papillary thyroid carcinoma (PTC) is a well‐differentiated malignancy derived from thyroid follicular epithelial cells. This study explores the functional role and underlying mechanisms of LINC01521 in PTC, aiming to provide new strategies to improve prognostic assessment and survival rates for PTC. Methods The study cohort comprised 120 patients with PTC. LINC01521 expression in PTC tissues and cells was quantified by qRT‐PCR. The association between LINC01521 and PTC malignant progression and adverse prognosis was evaluated by the chi‐square test. The target relationship between LINC01521 and miR‐4319 was confirmed by the starBase database. The effects of LINC01521 on PTC cell behavior and cuproptosis were examined by CCK8, Transwell, and related kits, and the potential regulatory mechanisms involved were further elucidated. Results LINC01521 was markedly upregulated in PTC tissues and cells. High LINC01521 expression is closely linked to the malignant clinical features of PTC, including more tumor lesions, increased tumor size, more advanced TNM staging, higher LNM rates, and poorer tumor differentiation. LINC01521 is an independent prognostic risk factor for PTC. Elevated LINC01521 levels indicated shorter overall survival. LINC01521 targets and regulates miR‐4319. LINC01521 knockdown led to a significant decrease in the proliferation, migration, and invasion of PTC cells. LINC01521 overexpression attenuated ES + Cu 2+ induced cuproptosis, while miR‐4319 overexpression reversed these effects. Conclusion LINC01521 acts as a promising prognostic marker for predicting PTC malignant progression and adverse outcomes. LINC01521 promotes PTC progression by affecting PTC cell function and inhibiting cuproptosis, and the possible regulatory mechanism is through targeting miR‐4319. Level of Evidence 3.