Tongguanteng injection (TGT) is widely utilized in China for treating or supporting therapy in multiple cancer types; however, its therapeutic efficacy and underlying mechanisms in osteosarcoma remain largely unexplored. Osteosarcoma cell lines 143B and MG-63 were exposed to varying concentrations of TGT. Cellular proliferation, migration, invasion, and apoptosis were assessed using CCK8 assays, transwell assays, and flow cytometry. Differentially expressed genes (DEGs) were identified via RNA sequencing (RNA-seq). The expression of key mRNAs and proteins linked to the IRE1/CHOP pathway was validated using RT-PCR and western blot analyses. To investigate the mechanism, the ER stress inhibitor 4-phenylbutyric acid (4-PBA) was employed. Additionally, 143B cells were transfected with siRNA to silence IRE1 or with the pEX‐3-ERN1 plasmid to induce IRE1 overexpression. Downstream effectors, including CHOP and apoptosis-related proteins caspase-3 and PARP1, were examined. The in vivo anti-tumor effects of TGT were evaluated using a 143B xenograft mouse model, with tumor tissues subjected to H&E staining, TUNEL staining, and immunohistochemistry.
TGT markedly inhibited proliferation, migration, and invasion while promoting apoptosis in 143B and MG-63 osteosarcoma cells in vitro. Key DEGs included HSPA5 (encoding BiP), ERN1 (encoding IRE1), and DDIT3 (encoding CHOP), with “IRE1-mediated unfolded protein response” emerging as the most significantly enriched GO biological process. TGT treatment upregulated ER stress-associated proteins ATF6, BiP, p-IRE1, XBP1s, and CHOP, as well as cleaved caspase-3 and PARP1, suggesting induction of apoptosis via the IRE1/CHOP pathway. Inhibition of ER stress with 4-PBA or IRE1 knockdown attenuated TGT-induced expression of these proteins, whereas IRE1 overexpression enhanced CHOP levels and apoptosis. Consistently, in vivo administration of TGT suppressed tumor growth and increased p-IRE1 and CHOP expression in xenografted mice. significant anti-osteosarcoma activity both in vitro and in vivo, potentially through activation of the ER stress-related IRE1/CHOP pathway, highlighting this pathway as a promising therapeutic target in osteosarcoma.
