AB179. KCNJ1 inhibits tumor proliferation and metastasis and is a prognostic factor in clear cell renal cell carcinoma

OBJECTIVE: Potassium inwardly-rectifying channel, subfamily J, member 1 (KCNJ1), plays an essential role in potassium balance by transporting potassium out of cells. KCNJ1 variation is associated with multiple diseases, such as antenatal Bartter syndrome and diabetes. However, the role of KCNJ1 in clear cell renal cell carcinoma (ccRCC) is still unknown. The aim of this study was to detect the expression of KCNJ1 in ccRCC and determine the relationship of KCNJ1 expression with the progression and prognosis of ccRCC. METHODS: Expression of KCNJ1 was evaluated in ccRCC tissues and cell lines by qRT-PCR, Western blot and immunohistochemistry analysis. The relationship between KCNJ1 expression and clinicopathological characteristics was analyzed. P3xFLAG-CMV-14 vector containing KCNJ1 was constructed, and used for infecting ccRCC cell lines 786-O and Caki-2. The effects of KCNJ1 on cell proliferation, invasion and apoptosis were detected in ccRCC cell lines using cell proliferation assay, transwell assay and flow cytometry. RESULTS: KCNJ1 was low-expressed in ccRCC tissues samples and cell lines. The KCNJ1 expression level was significantly associated with tumor pathology grade (P=0.002), and clinical stage (P=0.023). Furthermore, the KCNJ1 expression was a prognostic factor of ccRCC patient’s survival (P=0.033). The re-expression of KCNJ1 in 786-O and Caki-2 significantly inhibited cancer cell growth and invasion, and promoted cancer cell apoptosis. CONCLUSIONS: Taken together, we concluded that KCNJ1, low-expressed in ccRCC and associated with poor prognosis, plays an important role in ccRCC cell growth and metastasis.