MicroRNA PC-3p-2869 Regulates Antler Growth and Inhibits Proliferation and Migration of Human Osteosarcoma and Chondrosarcoma Cells by Targeting CDK8, EEF1A1, and NTN1

MicroRNAs (miRNAs) play a crucial role in maintaining the balance between the rapid growth and suppression of tumorigenesis during antler regeneration. This study investigated the role of a novel miRNA, PC-3p-2869 (miR-PC-2869), in antler growth and its therapeutic potential in human osteosarcoma and chondrosarcoma. Stem-loop RT-qPCR showed that miR-PC-2869 was expressed extensively in diverse layers of antler tissues. Overexpression of miR-PC-2869 suppressed the proliferation and migration of antler cartilage cells. Similarly, heterologous expression of miR-PC-2869 reduced the proliferation, colony formation, and migration of osteosarcoma cell line MG63 and U2OS and chondrosarcoma cell line SW1353. Moreover, 18 functional target genes of miR-PC-2869 in humans were identified based on the screening of the reporter library. Among them, 15 target genes, including CDK8, EEF1A1, and NTN1, possess conserved miR-PC-2869-binding sites between humans and red deer (Cervus elaphus). In line with this, miR-PC-2869 overexpression decreased the expression levels of CDK8, EEF1A1, and NTN1 in MG63, SW1353, and antler cartilage cells. As expected, the knockdown of CDK8, EEF1A1, or NTN1 inhibited the proliferation and migration of MG63, SW1353, and antler cartilage cells, demonstrating similar suppressive effects as miR-PC-2869 overexpression. Furthermore, we observed that CDK8, EEF1A1, and NTN1 mediated the regulation of c-myc and cyclin D1 by miR-PC-2869 in MG63, SW1353, and antler cartilage cells. Overall, our work uncovered the cellular functions and underlying molecular mechanism of antler-derived miR-PC-2869, highlighting its potential as a therapeutic candidate for bone cancer.