No abstract

Osteoclasts (OCs) and regulatory CD4+ T cells (CD4+Tregs) are important components in the tumor microenvironment (TME) of osteosarcoma. In this study, we collected six osteosarcoma samples from our previous study (GSE162454). We also integrated a public database (GSE152048), which included single cell sequencing data of 11 osteosarcoma patients. We obtained 138,192 cells and then successfully identified OCs and CD4+Tregs. Based on the interaction gene set between OCs and CD4+Tregs, patients from GSE21257 were distinguished into two clusters by consensus clustering analysis. Both the tumor immune microenvironment and survival prognosis between the two clusters were significantly different. Subsequently, five model genes were identified by protein–protein interaction network based on differentially upregulated genes of cluster 2. Quantitative RT‐PCR was used to detect their expression in human osteoblast and osteosarcoma cells. A prognostic model was successfully established using these five genes. Kaplan–Meier survival analysis found that patients in the high‐risk group had worse survival (p = 0.029). Therefore, our study first found that cell–cell communication between OCs and CD4+Tregs significantly alters TME and is connected to poor prognosis of OS. The model we constructed can accurately predict prognosis for osteosarcoma patients.

Purpose To explore clinical characteristics, surgical strategies, and prognosis of spinal enchondroma. Methods We retrospectively analyzed eleven cases with primary benign spinal enchondroma who were treated in our institution between January 2008 and December 2016. Results Of the 11 patients included in our study, the average age was 43 years(range from 5–66 years). There were 7 men and 4 women. The lesions were mainly located in the lumbar and thoracic column with 5 cases and 4 cases respectively, and following by the cervical and sacral vertebrae with both 1 cases. Total tumor resection was used in 10 cases and curettage in one case. The average follow-up was 3.3 years(range from 2 to 6 years). Most of the cases had achieved satisfied therapeutic outcome with the symptoms disappeared. However, Case 9 developed into local recurrence and a second surgery was performed. Although the lesion have not recured any more after the second operation during the follow-up, the lower extremity paralysis had no improvement. Case 2 was sent to our hospital for the recurrence of the sacral tumor which was very closed to the common iliac artery.When the second operation was conducted, the artery was ruptured and the patient died from hemorrhagic shock. Conclusion To establish the diagnosis of spinal enchondroma is not always a simple job for the absence of specific clinical characteristics. The optimal treatment is total resection. Although spinal enchondroma is benign, a few cases can develop into local recurrence. Sacral enchondroma should be more vigilant for its fatal complications.