This study aimed to determine whether intra-articularly injected adipose-derived stem cells (ADSCs) inhibited articular cartilage degeneration during osteoarthritis (OA) development in a rabbit anterior cruciate ligament transection (ACLT) model. The paracrine effects of ADSCs on chondrocytes were investigated using a co-culture system. ACLT was performed on both knee joints of 12 rabbits. ADSCs were isolated from the subcutaneous adipose tissue. ADSCs with hyaluronic acid were intra-articularly injected into the left knee, and hyaluronic acid was injected into the right knee. The knees were compared macroscopically, histologically, and immunohistochemically at 8 and 12 weeks. In addition, cell viability was determined using co-culture system of ADSCs and chondrocytes. Macroscopically, osteoarthritis progression was milder in the ADSC-treated knees than in the control knees 8 weeks after ACLT. Histologically, control knees showed obvious erosions in both the medial and lateral condyles at 8 weeks, while cartilage was predominantly retained in the ADSC-treated knees. At 12 weeks, the ADSC-treated knees showed a slight suppression of cartilage degeneration, unlike the control knees. Immunohistochemically, MMP-13 expression was less in the ADSC-treated cartilage than in the control knees. The cell viability of chondrocytes co-cultured with ADSCs was higher than that of chondrocytes cultured alone. TNF-alpha-induced apoptotic stimulation was similar between the two groups. Intra-articularly injected ADSCs inhibited cartilage degeneration progression by homing to the synovium and secreting a liquid factor having chondro-protective effects such as chondrocyte proliferation and cartilage matrix protection.

Reports showing high recurrence rates for intralesional curettage and bone grafting have made the current treatment principle for fibrous dysplasia controversial. This study aimed to report the postoperative clinical outcomes from three minimally invasive surgical strategies we use for monostotic fibrous dysplasia (MFD). Twelve patients with MFD presenting with no pathologic fracture or deformity and treated with one of three surgical strategies—plain open biopsy, plain alpha-tricalcium phosphate (ATP) reconstruction, and prophylactic bridge plating—were included. There were nine men and three women, with median age of 38 years. Mean follow-up was 88 weeks. Five cases involved the proximal femur, two each involved the femoral and tibial diaphyses, and one each involved the distal humerus, radial diaphysis, and proximal tibia. All cases were reviewed for functional and radiological outcomes. Median time to full activity was 1 day (range 1 to 3) for the plain open biopsy group, while the prophylactic bridge-plating and plain ATP reconstruction groups had longer median recovery times (59 days, range 3 to 143, and 52 days, range 11 to 192, respectively). Musculoskeletal Tumor Society scores at last follow-up were excellent for all the cases (mean 29.6, range 25 to 30). Radiological analysis using Gaski et al.’s criteria showed plain open biopsy resulted in partial resolution of proximal femoral lesions, while ATP reconstruction and prophylactic plating resulted in no change and progression in this lesion site, respectively. For femoral diaphyseal lesions, prophylactic plating resulted in partial resolution, while ATP reconstruction resulted in no change. In the tibial diaphysis, prophylactic plating resulted in partial resolution, while plain open biopsy resulted in no change. For the lesions involving the distal humerus and the proximal tibia, plain open biopsy resulted in partial resolution, while for the radial diaphyseal lesion, ATP reconstruction resulted in no change. Radiological progression was limited in 11 (92%) cases, and none had postoperative complications. Plain open biopsies for asymptomatic lesions; prophylactic bridge plating for symptomatic, large diaphyseal lytic lesions; and plain ATP reconstructions for both small and large nondiaphyseal symptomatic lytic lesions may be acceptable alternatives to curettage-incorporating procedures for MFD.

Rhabdomyosarcoma, the most common soft tissue sarcoma noted in childhood, requires multimodality treatment, including chemotherapy, surgical resection, and/or radiation therapy. The majority of the patients with localized rhabdomyosarcoma can be cured; however, the long-term outcomes in patients with metastatic rhabdomyosarcoma remain poor. The standard chemotherapy regimen for patients with rhabdomyosarcoma is the combination of vincristine, actinomycin, and cyclophosphamide/ifosfamide. In recent clinical trials, modifications of the standard chemotherapy protocol have shown improvements in the outcomes in patients with rhabdomyosarcoma. In various type of malignancies, new treatments, such as molecular targeted drugs and immunotherapies, have shown superior clinical outcomes compared to those of standard treatments. Therefore, it is necessary to assess the benefits of these treatments in patients with rhabdomyosarcoma. Moreover, recent basic and clinical studies on rhabdomyosarcoma have reported promising therapeutic targets and novel therapeutic approaches. This article reviews the recent challenges and advances in the management of rhabdomyosarcoma.

Due to the rarity and heterogeneity of bone and soft-tissue sarcomas, investigation into molecular targets and new treatments has been particularly challenging. Although intensive chemotherapy and establishment of surgical procedures have improved the outcomes of patients with sarcoma, the curative rate of recurrent and metastatic sarcomas is still not satisfactory. Recent basic science research has revealed some of the mechanisms of progression and metastasis of malignancies including proliferation, apoptosis, angiogenesis, tumor microenvironment, migration, invasion, and regulation of antitumor immune systems. Based on these basic studies, new anticancer drugs, including pazopanib, trabectedin, eribulin, and immune checkpoint inhibitors have been developed and the efficacies and safety of the new drugs have been assessed by clinical trials. This review summarizes new molecular therapeutic targets and advances in the treatment for bone and soft tissue sarcomas.