Upregulation of GRP78 in Renal Cell Carcinoma and Its Significance

OBJECTIVES To investigate the expression of GRP78 in human renal cell carcinoma (RCC) and its significance. METHODS We studied RNA and tissue section of a tumor and adjacent nontumorous renal tissues obtained from radical nephrectomy specimens of 42 patients and RCC cell lines. We used reverse transcriptase-PCR and immunohistochemistry to detect the GRP78 mRNA and protein expression, respectively. RESULTS Reverse transcriptase-PCR revealed that GRP78 mRNA is positively expressed in RCC cell lines (786-0, OS-RC-2, and Caki-1); the GRP78 mRNA expression in the RCC and adjacent nontumorous renal tissues was 0.88 +/- 0.34 and 0.44 +/- 0.15, respectively (P < .001). The GRP78 protein was found in RCC cell lines. Immunohistochemistry results also showed that the level of GRP78 protein expression of RCC tissues was significantly higher than that of the adjacent nontumorous renal tissues (P < .001). The high levels of GRP78 mRNA and protein expression were related to the large tumor size and high clinical stage (P < .001) but not to sex, age, and cell differentiate (P < .05). CONCLUSIONS To our knowledge, the present study is the first to report the upregulated expression of GRP78 and that it is possibly involved in pathogenesis of RCC. UROLOGY 75: 603-607, 2010. (C) 2010 Elsevier Inc.