Expression of transcription factor Yin Yang 1 in human osteosarcomas

Osteosarcoma is the most common primary malignant bone tumour in children and adolescents.1–3 Although osteosarcoma is primarily a disease of adolescents and young adults, a different type of osteosarcoma linked to Paget’s disease occurs in older adults. The outcome for patients with osteosarcomas is poor with a 2-year overall survival rate of 15–20% following surgical resection, chemotherapy and radiotherapy.2,4,5 The most frequent site for metastasis is the lung.6 However, metastasis can also occur in other bones and soft tissue.6–9 Death fromosteosarcoma is usually the result of progressive pulmonary metastasis with respiratory failure due to widespread disease.1,10,11 Increasing the understanding of the basic biology of osteosarcoma is a priority for tumour prognosis as well as for providing indications of possible tumour targets for selective therapy. The transcription factor Yin Yang 1 (YY1) is a multifunctional DNA binding protein and an ubiquitously expressed member of a polycomb group of proteins.12–14 The transcription factor YY1 is known to be present in some human cancer cell lines and its expression correlates to immune-mediated apoptosis.15–20 Here, we demonstrate for the first time that the transcription factor YY1 is selectively expressed in human osteosarcoma cells and biopsies. The RT-PCR analysis confirmed the data obtained with immunohistochemistry. 0959-8049/$