Expression Profiling of Receptor-Activator of Nuclear Factor-Kappa B Ligand in Soft Tissue Tumors

Giant Cells of Various Lesions Are Characterised by Different Expression Patterns of HLA-Molecules and Molecules Involved in the Cell Cycle, Bone Metabolism, and Lineage Affiliation: An Immunohistochemical Study with a Review of the Literature

Giant cells (GCs) are thought to originate from the fusion of monocytic lineage cells and arise amid multiple backgrounds. To compare GCs of different origins, we immunohistochemically characterised the GCs of reactive and neoplastic lesions (n = 47). We studied the expression of 15 molecules including HLA class II molecules those relevant to the cell cycle, bone metabolism and lineage affiliation. HLA-DR was detectable in the GCs of sarcoidosis, sarcoid-like lesions, tuberculosis, and foreign body granuloma. Cyclin D1 was expressed by the GCs of neoplastic lesions as well as the GCs of bony callus, fibroid epulis, and brown tumours. While cyclin E was detected in the GCs of all lesions, p16 and p21 showed a heterogeneous expression pattern. RANK was expressed by the GCs of all lesions except sarcoid-like lesions and xanthogranuloma. All GCs were RANK-L-negative, and the GCs of all lesions were osteoprotegerin-positive. Osteonectin was limited to the GCs of chondroblastoma. Osteopontin and TRAP were detected in the GCs of all lesions except xanthogranuloma. RUNX2 was heterogeneously expressed in the reactive and neoplastic cohort. The GCs of all lesions except foreign body granuloma expressed CD68, and all GCs were CD163- and langerin-negative. This profiling points to a functional diversity of GCs despite their similar morphology.

Tenosynovial giant cell tumors (TGCT): molecular biology, drug targets and non-surgical pharmacological approaches

INTRODUCTION

Tenosynovial giant cell tumor (TGCT) is a mono-articular, benign or locally aggressive and often debilitating neoplasm. Systemic therapies are becoming part of the multimodal armamentarium when surgery alone will not confer improvements. Since TGCT is characterized by colony-stimulating factor-1 (CSF1) rearrangements, the most studied molecular pathway is the CSF1 and CSF1 receptor (CSF1R) axis. Inhibiting CSF1-CSF1R interaction often yields considerable radiological and clinical responses; however, adverse events may cause treatment discontinuation because of an unfavorable risk-benefit ratio in benign disease. Only Pexidartinib is approved by the US FDA; however, the European Medicines Agency has not approved it due to uncertainties on the risk-benefit ratio. Thus, there is a need for safer and effective therapies.

AREAS COVERED

Light is shed on disease mechanisms and potential drug targets. The safety and efficacy of different systemic therapies are evaluated.

EXPERT OPINION

The CSF1-CSF1R axis is the principal drug target; however, the effect of CSF1R inhibition on angiogenesis and the role of macrophages, which are essential in the postoperative course, needs further elucidation. Systemic therapies have a promising role in treating mainly diffuse-type, TGCT patients who are not expected to clinically improve from surgery. Future drug development should focus on targeting neoplastic TGCT cells.

Protective Effect of Oxytocin Against Bone Loss in a Female Rat Model of Osteoporosis

Background

Introduction: Oxytocin (OT) has been proposed to assist in the regulation of bone remodeling and to exert an antiosteoporotic effect. We evaluated the possible protective effect of OT against bone degeneration in ovariectomized (OVX) rats.

Methods

The study was performed on three groups of adult female rats; group I was subjected to sham operation, group II was subjected to ovariectomy, and group III was subjected to ovariectomy and intraperitoneal injection with OT for eight successive weeks. At the end of the study, bone mass density (BMD) was measured; then the rats were euthanized and their blood and bone tissues were examined.

Results

The group II rats had significantly less BMD and greater serum bone-specific alkaline phosphatase (bALP), osteocalcin (OC), and tartrate-resistant acid phosphatase (TRAP) levels than the group I rats. Furthermore, group II rats had fewer osteocytes and osteoblasts, and less OPG/RANKL mRNA expression than group I rats. The groups I and III and rats showed no significant differences in BMD, bALP, OC, TRAP, OPG/RANKL mRNA expression, or osteocyte and osteoblast numbers.

Conclusion

Oxytocin may have an antiosteoporotic effect in OVX rats.