Knocking down Siglec-15 in osteosarcoma cells inhibits proliferation while promoting apoptosis and pyroptosis by targeting the Siglec-15/STAT3/Bcl-2 pathway.

Purpose: Sialic acid-bound immunoglobulin lectin 15 (Siglec-15) plays a crucial role in many kinds of tumors. The relationship between Siglec-15 and the prognosis of osteosarcoma patients and its role in the apoptosis and pyroptosis of osteosarcoma cells are not sufficiently understood. Our study aimed to investigate the function of Siglec-15 in osteosarcoma cells and its effect on tumor cell proliferation, apoptosis and pyroptosis.

Materials And Methods: The Siglec-15 expression in pathological sections of osteosarcoma patients was analyzed and the overall survival time related to the expression of Siglec-15 was further analyzed. Next, we detected the expression of Siglec-15 in osteosarcoma cells and downregulated the expression of Siglec-15 by small interfering RNA (siRNA). The proliferation, apoptosis and pyroptosis of osteosarcoma cells were studied by proliferation and apoptosis kits and Western blotting. Furthermore, the Siglec-15 signaling pathway was examined, which may be involved in the observed cellular effects.

Results: We demonstrated the expression of Siglec-15 in osteosarcoma cells. SiRNA-mediated downregulation of Siglec-15 was successful. We found that knockdown of Siglec-15 in osteosarcoma cell lines significantly inhibited proliferation while promoting apoptosis. Further investigation showed that the expression of proliferation-related proteins was downregulated and that apoptosis- and pyroptosis-related proteins were upregulated. In addition, we found that Siglec-15 may inhibit proliferation while inducing apoptosis and pyroptosis via the (Signal Transducer and Activator of Transcription 3) STAT3/Bcl-2 pathway in osteosarcoma.

Conclusions: In this study, we demonstrated that the ablation of Siglec-15 in osteosarcoma inhibited proliferation and promoted apoptosis and pyroptosis by targeting the Siglec-15/STAT3/Bcl-2 pathway.