Molecular and phenotypic expression of decorin as modulator of angiogenesis in human potentially malignant oral lesions and oral squamous cell carcinomas

Background: Decorin is an extracellular matrix, multifunctional small proteoglycan molecule in tumor stroma that has been shown to be modulator of angiogenesis. No clinical data is available so far on decorin expression and survival outcome of oral cancer. Aim: The aim of the present study was to examine molecular and phenotypic expression of two angiogenesis modulators viz. decorin and vascular endothelial growth factor-A (VEGF-A) in human potentially malignant oral lesions (PMOLs) and oral squamous cell carcinomas (OSCC) in relation to clinico-pathological variables and survival outcome. Materials and Methods: Tissue biopsies were obtained from 72 PMOLs, 108 OSCC and 52 healthy controls. The PMOLs included cases of leukoplakias and oral submucous fibrosis. Immunohistochemistry was performed using antibodies against decorin, VEGF-A and CD-31. Messenger-ribonucleic acid (mRNA) expression was analyzed by using real-time polymerase chain reaction. Results: Cytoplasmic staining of decorin was observed in the basal layer of epithelium in 53 (73.61%) cases of PMOLs and in peritumoral stroma in 55 (50.92%) cases of OSCC. None of the cases showed nuclear expression of decorin. Decorin expression both at phenotypic and molecular level was found to be down-regulated from PMOLs to OSCC. Lymph node metastasis and reduced decorin expression independently correlated with overall survival in OSCC. VEGF-A expression had no significant impact on survival outcome. Conclusion: Micro vessel density and VEGF-A expression were significantly associated with reduced decorin expression in tumor stroma suggesting, decorin as angiogenic modulator in OSCC. Down-regulation of decorin expression and the presence of lymph node metastasis were adverse factor independently affecting overall survival in OSCC.