Expression and significance of N-myc downstream regulated gene 1 in renal cell carcinoma

Abstract

Objective To study the expression of N-myc downstream regulated gene 1 (NDRG1) in renal cell carcinoma and its relationship with microvessel density (MVD) and clinicopathologic parameters.Methods Immunohistochemical study for NDRG1 and CD34 was performed on paraffin sections of cases of renal cell carcinoma and adjacent non-neoplastic renal parenchymal tissue. MVD was analyzed by CD34immunostaining.Results Immunohistochemical study showed that non-neoplastic proximal convoluted tubule, distal convoluted tubule and collecting ducts was positive for NDRG1 (membranous and cytoplasmic). The expression rate of NDRG1 in renal cell cancer was 51%, which was significantly lower than that in normal renal tissues of 100 % (P ＜0.05).Clinicpathologically, the result also showed a close relation between lower NDRG1 expression and higher pathologic grade (χ2 =9.968, P =0.007), later clinic stage (χ2= 6.437,P =0.011), lymph node metastases (χ2=5.800, P =0.016) and higher MVD of cancer (t =2.235, P =0.030)whereas no relation with other factors. Conclusion NDRG1 might play as a cancer suppressor gene in renal cell carcinoma in that it could be correlated with tumor invasion and metastasis.It might also suppress tumor growth and metastasis by regulation of tumor angiogenesis. Key words: Carcinoma, renal cell; Gene, myc; Microvessel density