Innovative Breakthroughs for the Treatment of Advanced and Metastatic Synovial Sarcoma

Low NT5DC2 expression predicts favorable prognosis and suppresses soft tissue sarcoma progression via ECM-receptor interaction pathway

BACKGROUND

Soft tissue sarcoma, a malignant tumor arising from mesenchymal tissues with poor prognosis. 5'-Nucleotidase Domain Containing 2 (NT5DC2) is a novel oncogene, and the precise involvement of NT5DC2 in soft tissue sarcoma were still undefined. Hence, our study aims to investigate NT5DC2 functions in soft tissue sarcoma progression.

METHODS

The tumor immune single-cell hub 2 (TISCH2) website, The Cancer Genome Atlas (TCGA) pan-cancer or sarcoma and Gene Expression Omnibus (GEO, GSE21122) databases were applied to visualize the NT5DC2 status in the sarcoma databases. The NT5DC2 protein expression in sarcoma tissues in our hospital was detected by using immunohistochemistry (IHC) and analyzed the associations between NT5DC2 expression and clinicopathological parameters. Real-time quantitative polymerase chain reaction (RT-qPCR), colony formation, 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing, transwell, flow cytometry and xenograft model were used to elucidate the effects of NT5DC2 downregulated by lentivirus in sarcoma cell.

RESULTS

The TISCH2 website detection found that NT5DC2 expression is enriched in malignant cells in sarcoma single-cell database. Furthermore, the TCGA-sarcoma database indicated that NT5DC2 expression correlates with metastasis, positive margin status, prognosis, and diagnostic value. Additionally, IHC staining showed that 40 % of soft tissue sarcoma patients present high expression of NT5DC2, and NT5DC2 upregulation is closely associated with poor prognosis. Functional verification analysis further revealed that downregulating NT5DC2 expression can suppress sarcoma progression through the ECM-receptor interaction pathway.

CONCLUSION

Low expression of NT5DC2 predicts a favorable prognosis in soft tissue sarcoma, and downregulated NT5DC2 expression can suppress sarcoma cell progression through the ECM-receptor interaction pathway.

DNA-Dependent Protein Kinase Inhibitor Peposertib Potentiates the Cytotoxicity of Topoisomerase II Inhibitors in Synovial Sarcoma Models

Synovial sarcoma is a rare and highly aggressive subtype of soft tissue sarcoma. The clinical challenge posed by advanced or metastatic synovial sarcoma, marked by limited treatment options and suboptimal outcomes, necessitates innovative approaches. The topoisomerase II (Topo II) inhibitor doxorubicin has remained the cornerstone systemic treatment for decades, and there is pressing need for improved therapeutic strategies for these patients. This study highlights the potential to enhance the cytotoxic effects of doxorubicin within well-characterized synovial sarcoma cell lines using the potent and selective DNA-PK inhibitor, peposertib. In vitro investigations unveil a p53-mediated synergistic anti-tumor effect when combining doxorubicin with peposertib. The in vitro findings were substantiated by pronounced anti-tumor effects in mice bearing subcutaneously implanted tumors. A well-tolerated regimen for the combined application was established using both pegylated liposomal doxorubicin (PLD) and unmodified doxorubicin. Notably, the combination of PLD and peposertib displayed enhanced anti-tumor efficacy compared to unmodified doxorubicin at equivalent doses, suggesting an improved therapeutic window-a critical consideration for clinical translation. Efficacy studies in two patient-derived xenograft models of synovial sarcoma, accurately reflecting human metastatic disease, further validate the potential of this combined therapy. These findings align with previous evidence showcasing the synergy between DNA-PK inhibition and Topo II inhibitors in diverse tumor models, including breast and ovarian cancers. Our study extends the potential utility of combined therapy to synovial sarcoma.

PROTAC-Based Protein Degradation as a Promising Strategy for Targeted Therapy in Sarcomas

Sarcomas are heterogeneous bone and soft tissue cancers representing the second most common tumor type in children and adolescents. Histology and genetic profiling discovered more than 100 subtypes, which are characterized by peculiar molecular vulnerabilities. However, limited therapeutic options exist beyond standard therapy and clinical benefits from targeted therapies were observed only in a minority of patients with sarcomas. The rarity of these tumors, paucity of actionable mutations, and limitations in the chemical composition of current targeted therapies hindered the use of these approaches in sarcomas. Targeted protein degradation (TPD) is an innovative pharmacological modality to directly alter protein abundance with promising clinical potential in cancer, even for undruggable proteins. TPD is based on the use of small molecules called degraders or proteolysis-targeting chimeras (PROTACs), which trigger ubiquitin-dependent degradation of protein of interest. In this review, we will discuss major features of PROTAC and PROTAC-derived genetic systems for target validation and cancer treatment and focus on the potential of these approaches to overcome major issues connected to targeted therapies in sarcomas, including drug resistance, target specificity, and undruggable targets. A deeper understanding of these strategies might provide new fuel to drive molecular and personalized medicine to sarcomas.

Current stand on systemic therapy in localized soft tissue sarcomas: a clinician's perspective

Soft tissue sarcomas (STS) are rare heterogenous tumors derived from mesenchymal tissue. While surgery represents the primary treatment modality, the high recurrence rates following surgery alone necessitate consideration for systemic therapy in high-risk sarcomas. Despite multiple trials and meta-analyses over the last 3 decades, the role of chemotherapy remains controversial. It is crucial to accurately identify patients with high-risk diseases who may benefit the most from adjuvant and/or neoadjuvant chemotherapy. There is renewed interest in the potential to improve outcomes in localized resectable STSs with the addition of targeted and immunotherapeutic strategies. The review presented here is a summary of current evidence on systemic therapy in resectable localized STSs of the trunk and extremities to facilitate clinician decision-making.