Development and validation of a novel disulfidptosis-related gene signature for prediction of survival and immune microenvironment in osteosarcoma by WGCNA analysis

Disulfidptosis was reported to be associated with the malignant progression of various tumors. This study was aimed to investigate the prognostic significance of disulfidptosis-related genes (DRGs) in osteosarcoma (OS). Ten previously reported core disulfidptosis genes were used for consensus clustering and WGCNA analyses. A total of 338 disulfidptosis-related genes (DRGs) were identified. Then, uni-COX, LASSO and multi-COX analyses were conducted, identifying 5 prognosis-related DRGs (BTN3A1, CEBPA, KCNAB2, TBX21, and MYC). A prognostic DRGs risk signature based on the five genes were constructed and validated. OS patients were divided into high and low risk groups by risk scores. K-M plots and t-ROC curves showed that patients with high-risk scores had worse prognosis. Patients in the high-risk group had lower abundance of immune checkpoint-related genes, including CD274 (PD-L1), LAG3, PDCD1LG2 (PD-L2), and BTLA. Besides, patients in the high-risk group exhibited lower IC50 values for vorinostat, elesclomol, OSI-906, pyrimethamine, thapsigargin, and doxorubicin, but a higher IC50 value for cisplatin, compared to those in the low-risk group, indicating differential drug sensitivities. Additionally, analysis of immune checkpoint blockade (ICB) response revealed that patients in the high-risk group had a lower predicted response rate to immunotherapy. The mRNA expression levels of 4 DRGs including BTN3A1, KCNAB2, TBX21 and CEBPA in OS cells were significantly lower than those in hFOB1.19 cells. Subsequent experiments revealed that BTN3A1 protein was expressed at low levels in OS cells. Furthermore, overexpression of BTN3A1 significantly suppressed OS cell proliferation, migration, and invasion. In summary, we established a robust DRGs signature comprising BTN3A1, CEBPA, KCNAB2, TBX21, and MYC, which showed strong prognostic value and predictive potential for immune status and drug sensitivity in OS. Notably, functional experiments confirmed that BTN3A1 acted as a tumor suppressor in OS, highlighting it as a promising therapeutic target.