SIRT4 protein levels are downregulated in kidney renal clear cell carcinoma

Background: Several members of the SIRT family (SIRT1-7), a highly-conserved family of NAD+-dependent enzymes, play an important role in tumor formation. Recently, several studies have suggested that SIRT4 may also function as both a tumor oncogene and a tumor suppressor gene. However, no studies have assessed its clinical significance in kidney renal clear cell carcinoma (KIRC). Methods: We investigated SIRT4 protein levels in neoplastic tissues from KIRC patients and its possible association with selected clinicopathological parameters by immunohistochemical staining of a tissue microarray that included 122 KIRC patient tissue samples. Results: SIRT4 protein levels in KIRC were markedly lower than their non-neoplastic tissue counterparts (P < 0.001). The average survival time of patients with low SIRT4 expression of KIRC was lower than that of patients with high SIRT4 expression, especially in patients older than 60 years and with pathological grade III-IV. Conclusions: Our results indicate that SIRT4 may play a role in the development of KIRC.