Effect of the hypoxia on the expression of zinc transporters in renal adenocarcinoma cell line

Abstract

INTRODUCTION: Renal cell carcinoma (RCC) is a tumor responsible for about 1 to 3 % of all malignancies. The most common histological variant is the clear cell carcinoma (ccRCC), representing about 45% of all cases of RCC in adults. ccRCC is associated with the VHL gene mutation. The loss of the VHL protein prevents the degradation of HIF subunits, which are involved in critical oncogenic pathways. Zinc is an essential trace element and its cellular homeostasis is regulated by zinc transporters such as ZIPs and ZNTs. The profile of their expression in renal tumor is still unknown. OBJECTIVES: Evaluate the expression profile of zinc transporters in ccRCC in normoxia and hypoxia culturing conditions. MATERIALS AND METHODS: 786-0 tumor cells were cultured in hypoxic conditions inside a hypoxia chamber with an oxygen absorber to the atmosphere of 1% O2, 5% CO2, and 94% N2, and placed in an incubator at 37°C for 24 hours. The Altair PRO Single-Gas Detector was used to measure the percentage of O2. For gene expression analysis, RTq-PCR was used and the results were analyzed by the Delta-Delta ct method. DISCUSSION AND RESULTS: VEGF and HIF2a expression in 786-0 cells were evaluated to confirm the efficacy of hypoxia chamber. There was a significant increase in the VEGF expression of 312.8±2.14% (P< 0.0001) and HIF2a of 593.4±57.21% (P< 0.0092). Besides that, the gene expression analysis revealed a downregulation in the hypoxic environment of the channels ZNT9 of 71.41±0.84% (P< 0.0001), ZIP1 of 17.45±3.68% (P< 0.0418), ZIP4 of 76.3±9.75% (P< 0.0054) and ZIP10 of 44.96±4.31% (P< 0.0001). CONCLUSION: The hypoxia modulates the expression of Zn channels in 786-0 cells indicating that such channels play a role in the pathophysiology of ccRCC.