Transition from Tumor Tissue to Bone Marrow in Patients with Appendicular Osteosarcoma after Neoadjuvant Chemotherapy

Prognostic analysis of telangiectatic osteosarcoma of the extremities

Background and objectives

Telangiectatic osteosarcoma (TOS) is a rare but highly malignant subtype of osteosarcoma. Although surgical treatment is the primary treatment modality for osteosarcoma, evidence on the benefits of different surgical methods in patients with TOS is lacking. This study aimed to compare the effects of different surgical and adjuvant treatments on overall survival of TOS, and the association of patient demographics, oncological characteristics, and socioeconomic status on treatment outcomes.

Method

This retrospective study selected the most common TOS cases of the extremities registered in the Surveillance, Epidemiology, and End Results (SEER) database from 1989 to 2019. Univariate and multivariate Cox regression models were used to analyze all prognostic factors, and Kaplan-Meier analyses were performed for disease-specific treatment factors of survival.

Result

A total of 127 patients were included in the analysis. The average age at initial diagnosis was 20.09 years. In univariate analyses, the absence of metastasis at initial diagnosis, limb-salvage surgery, adjuvant chemotherapy, and no regional lymph node dissection were associated with a lower risk of death. Multivariate analysis further showed that the presence or absence of distant metastasis and regional lymph node dissection, implementation of adjuvant chemotherapy, and choice of surgical method were independent predictors of prognosis.

Conclusion

Distant metastasis and regional lymph node dissection are associated with poorer outcomes in TOS, and amputation has no better prognosis than limb salvage surgery. Compared with conventional chemotherapy, neoadjuvant chemotherapy did not significantly improve the prognosis of TOS.

Diosgenin inhibits the epithelial-mesenchymal transition initiation in osteosarcoma cells via the p38MAPK signaling pathway

Diosgenin is an important basic raw material for the production of steroid hormone drugs. It can be isolated and purified from a variety of traditional Chinese medicines or plants. Modern molecular biological studies have shown that diosgenin inhibits various tumor cells migration and invasion ability to varying degrees in vitro and in vivo. The aim of the present study was to observe the inhibitory effects of diosgenin on the invasive and metastatic capabilities of osteosarcoma cells and to determine the association between the effects of diosgenin on the epithelial-mesenchymal transition (EMT). Wound healing and Transwell assays were used to observe the inhibitory effects of diosgenin on the invasion and migration of two osteosarcoma cell lines. Immunofluorescence was used to observe changes in transforming growth factor β1 (TGF-β1) protein expression levels in the osteosarcoma cells following drug administration. EMT-associated proteins, including TGFβ1, E-cadherin and vimentin were detected by western blotting, which demonstrated that the drug may inhibit the initiation of EMT in osteosarcoma cells. Western blot analysis of the expression of all the proteins in the mitogen-activated protein kinase (MAPK) pathway demonstrated that the drug inhibited the MAPK signaling pathway. The primary mechanism of action of diosgenin was the inhibition of the phosphorylated p38 (pP38) protein. Through a combination of inhibitors of the p38MAPK signaling pathway and detection of the downstream EMT marker protein E-cadherin by quantitative PCR, pP38 was confirmed to be a target of diosgenin in the inhibition of EMT in the osteosarcoma cells via the MAPK molecular signaling pathway. Diosgenin may exhibit utility as an auxiliary drug for the clinical reduction of metastasis in patients with osteosarcoma.