RT-PCR Assay of RECK Gene and Osteopontin Immuno-expression in Jaw Osteosarcoma: Correlation with Clinical Behavior and Histological Subtypes

Abstract

Osteosarcoma of the jaws is an aggressive, malignant mesenchymal tumor, which is characterized by the formation of osteoid tissue. There are multiple factors that have an influence on the prognosis of OS, The well-known prognostic factors are age, tumor site, tumor size and histological type. Reversion-Inducing-Cysteine-Rich Protein With Kazal Motifs, a novel MMP inhibitor is widely expressed in various normal human tissues but is downregulated in tumor cell lines and oncogenically transformed cells. RECK gene encodes a membrane-anchored glycoprotein that suppresses tumor invasion and angiogenesis by regulating MMP-2, MMP-9 and MT1-MMP by unknown mechanism. This suggests that RECK may be involved during tumor progression, invasion and metastasis.

Osteopontin is a secreted and calcium binding phosphorylated glycoprotein and expressed constitutively in a limited number of normal tissues, stress-responsive physiological conditions, and abnormally elevated in some pathological conditions. OPN is considered as cytokine that regulates cell pathways in the immune system. OPN was also expressed in various malignancies and may play important role in tumorigenesis, tumor invasion, and metastasis in various malignancies. In addition, OPN expression was associated with poor prognosis. OPN was also suggested to be a clinically useful marker for predicting biochemical recurrence for many tumors.