The aim of the present study was to determine the expression and function of B cell translocation gene 1 (BTG1) in kidney carcinoma. Kidney samples were obtained from cancer lesions (n=85) and the adjacent normal tissue (n=40) in kidney cancer patients immediately following endoscopic biopsy. The effect of BTG1 overexpression was examined in vitro utilizing a human kidney cancer cell line, ACHN, stably transfected with a recombinant lentivirus (LeBTG1 cells) and compared to empty vector-transfected controls (LeEmpty). BTG1 protein expression was significantly lower in kidney cancer tissue biopsies compared to normal tissue, as measured by immunohistochemistry (34.1 vs. 77.8% of tissues; P<0.05) and western blotting (0.481 +/- 0.051 vs. 0.857 +/- 0.081; P<0.05). In vitro analyses revealed that LeBTG1 cells had a reduced survival fraction compared to control LeEmpty cells, with higher rates of apoptosis (16.6 +/- 2.5 vs. 6.1 +/- 0.7%; P<0.05). The proportion of LeBTG1 cells in G(0)/G(1), stage and S phase was also significantly different from LeEmpty cells (66.8 +/- 5.3 and 22.2 +/- 1.5% vs. 44.4 +/- 3.1 and 34.5 +/- 2.3%, respectively; P<0.05), and the migration and invasion of LeBTG1 cells was significantly impaired with respect to LeEmpty cells (74.0 +/- 9.0 and 53.0 +/- 7.0 vs. 118.0 +/- 15.0 and 103.0 +/- 13.0, respectively; P<0.05). These effects were accompanied by decreased protein expression of cyclin D1, B-cell lymphoma 2 and matrix metalloproteinase 9 in LeBTG1 cells (0.118 +/- 0.018, 0.169 +/- 0.015 and 0.207 +/- 0.027, respectively) compared to control LeEmpty cells (0.632 +/- 0.061, 0.651 +/- 0.063 and 0.443 +/- 0.042, respectively; P<0.05). Reduced BTG1 expression is associated with increased disease severity, suggesting it is a negative regulator of kidney cancer and can serve as a prognostic indicator. The results of the present study show that BTG1 protein levels were significantly reduced in kidney cancer biopsy specimens and were associated with disease progression and prognosis.