Association between the expression of inhibitor of growth family member 4 and the progression of clear cell renal carcinoma.

Inhibitor of growth family member 4 (ING4) is a candidate tumor suppressor that serves important roles in tumor growth and angiogenesis. In the present study ING4 expression was assessed in clear cell renal carcinoma (CCRC) tissues and its association with the progression of CCRC was determined. The expression of ING4 in 125 patients with CCRC was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunohistochemical methods. A total of 40 adjacent normal renal tissues were used as control samples. The results identified that ING4 expression was positive in 100% of normal renal tissues, but in only 82.3% CCRC samples. RT-qPCR and western blotting results demonstrated that expression levels of ING4 mRNA and protein were significantly decreased in CCRC compared with in normal tissues (P<0.0001). ING4 expression was not associated with sex, age or tumor volume (P>0.05), but was associated with the nuclear grade of renal cancer (P<0.0001), the clinical stage of CCRC (P<0.0001) and lymphatic metastasis (P<0.0001). The results of the present study indicated that dysregulation of ING4 expression may be involved in the initiation and progression of CCRC.