OBJECTIVE: Although germline mutations of fumarate hydratase (FH) are a useful molecular marker of hereditary leiomyomatosis and renal cell cancer (RCC) syndrome, their clinical significance in sporadic RCC has not been studied in detail. The aim of the present study was to investigate possible correlations between the expression of FH and the clinical implications of sporadic RCC. MATERIALS AND METHODS: FH mRNA levels were evaluated in 140 tumor specimens from patients with primary RCC and in 62 specimens of corresponding normal-appearing kidney tissue using real-time quantitative polymerase chain reaction. Immunohistochemical staining was performed on 6 normal surrounding tissues and 71 RCC tissues. RESULTS: FH mRNA levels were significantly lower in tumor tissues than in matched normal-appearing kidney tissues (p = 0.031). In all normal tissues, FH staining intensity was strong. However, the expression of FH showed no significant correlation with the pathological and clinical characteristics of patients with sporadic RCC. CONCLUSIONS: Our results showed that FH mRNA expression decreased significantly in correlation with the transition from normal renal parenchyma to RCC. FH may be an indicator or tumorigenesis in sporadic RCC and could be a potential target for therapies against RCC in the future.
OBJECTIVE: Although germline mutations of fumarate hydratase (FH) are a useful molecular marker of hereditary leiomyomatosis and renal cell cancer (RCC) syndrome, their clinical significance in sporadic RCC has not been studied in detail. The aim of the present study was to investigate possible correlations between the expression of FH and the clinical implications of sporadic RCC. MATERIALS AND METHODS:FH mRNA levels were evaluated in 140 tumor specimens from patients with primary RCC and in 62 specimens of corresponding normal-appearing kidney tissue using real-time quantitative polymerase chain reaction. Immunohistochemical staining was performed on 6 normal surrounding tissues and 71 RCC tissues. RESULTS:FH mRNA levels were significantly lower in tumor tissues than in matched normal-appearing kidney tissues (p = 0.031). In all normal tissues, FH staining intensity was strong. However, the expression of FH showed no significant correlation with the pathological and clinical characteristics of patients with sporadic RCC. CONCLUSIONS: Our results showed that FH mRNA expression decreased significantly in correlation with the transition from normal renal parenchyma to RCC. FH may be an indicator or tumorigenesis in sporadic RCC and could be a potential target for therapies against RCC in the future.