Practical radiation oncology for extremity sarcomas

High expression of ACKR1 predicts a good prognosis and suppresses sarcoma cell progression via regulating the tumor immune microenvironment

Sarcoma is a malignant tumor originating from mesenchymal tissue with a poor prognosis. Atypical chemokine receptor 1 (ACKR1) is found closely related to cancer progression. However, the effects of ACKR1 in soft tissue sarcoma have not been well investigated. Therefore, our present study is devoted to analyze the functions of ACKR1 in sarcoma progression and its potential mechanism. We detected the expression of ACKR1 in the Cancer Genome Atlas (TCGA)-pan-cancer database, TCGA-Sarcoma from TCGA databases, and GSE21122 from Gene Expression Omnibus (GEO) database. The relationships between ACKR1 expression, clinicopathological data, and survival status were evaluated in the TCGA-Sarcoma database. Moreover, overexpression negative control (OE-NC) and overexpression ACKR1 (OE-ACKR1) were used to further verify the effects of ACKR1 overexpression in the progression of sarcoma cells by using Reverse Transcription-Quantitative Polymerase Chain Reaction (RT-qPCR), cell counting kit-8 (CCK-8), 5-Ethyny-2'-Deoxyuridine (EdU), wound healing, transwell assay, and flow cytometry assays. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) analyses were carried out to explore the potential enriched biological process of ACKR1 expression in sarcoma. Furthermore, tumor-immune system interactions databases (TISIDB) were applied to further confirm the relations between ACKR1 and tumor immune microenvironment in sarcoma. Our study found that ACKR1 is downregulated in multiple cancers (including sarcoma), and low expression of ACKR1 is related to poor survival status in sarcoma. The biological experiments found that promoting expression of ACKR1 can suppress sarcoma cell proliferation, migration, invasion, promote cell apoptosis, and arrest cell cycle. The GO-KEGG, GSEA, and TISIDB analysis showed that ACKR1 is related to the tumor immune microenvironment. In conclusion, low expression of ACKR1 presented as an independent prognostic biomarker in sarcoma. Overexpression of ACKR1 can significantly suppress cell progression ability in sarcoma by regulating the immune microenvironment.

Double-Pedicled Free Deep Inferior Epigastric Perforator Flap for the Coverage of Thigh Soft-Tissue Defect

Soft-tissue defects caused by radiation injury are a challenging task for the reconstructive surgeon, due to the extent of the soft-tissue damage and the associated injuries of the local blood vessels and bone tissue. We present the application of the versatile deep inferior epigastric perforator (DIEP) flap for the coverage of an extended lateral thigh soft-tissue defect after the surgical resection of an undifferentiated pleomorphic high-grade sarcoma, neoadjuvant chemotherapy, and adjuvant chemo- and radiotherapy. A double-pedicled free DIEP flap (756 cm²) was harvested and anastomosed to the transverse branch of the lateral femoral circumflex artery and a lateral branch of the popliteal artery (P1). The flap survived completely without serious complications, and the patient was able to walk with crutches 3 months postoperatively. This is the first case report of a free bipedicled DIEP flap for the coverage of a thigh defect in a male patient.