has been found to be downregulated in papillary thyroid carcinoma (PTC), while little is known about the cellular functions and precise signals elicited by miR-141-3p in PTC. The results of this study indicated that the expression of miR-141-3p was aberrantly down-regulated in PTC tissues and cell lines, compared with the adjacent normal tissues and normal thyroid epithelial cells. Furthermore, the miR-141-3p expression level was negatively associated with TNM stage and lymph node metastasis in PTC. Expression of miR-141-3p effectively inhibited cell growth, promoted apoptosis, and suppressed invasion in PTC cells. Meanwhile, miR-141-3p knockdown with miR-141-3p inhibitor reversed these effects. Consistent with the in vitro study, miR-141-3p also exhibited anti-neoplastic activity in vivo. Moreover, the results revealed that miR-141-3p directly recognized the 3 0 untranslated region (3 0 UTR) of Yin Yang 1 (YY1) and negatively regulated the expression of YY1 at both protein and mRNA levels. Ectopic expression of YY1 could effectively abrogate the anti-metastatic and proapoptotic effects of miR-141-3p. In summary, the findings suggested that miR-141-3p can act as a tumor suppressor in PTC and may be a potential therapeutic target for PTC treatment. Anat Rec, 302:258-268, 2019. -3p; YY1; tumor growth; metastasis 10%-15% of patients will relapse and develop distant metastases, leading to a poor clinical outcome (Sipos and Mazzaferri, 2010). Thus, further exploring the underlying mechanisms contributing to the occurrence, progression, and metastasis of PTC may provide insight into the novel target therapies. MicroRNAs (miRNAs) belong to a group of small noncoding RNA, and play a pivotal role in various physiological and pathological processes during cancer development