Effects of HIF2a in renal cancer metastasis and sensitivity to repurposed drugs

Background: in clear cell renal cell carcinoma (ccRCC), 80% of cases have biallelic inactivation of VHL gene, leading to constitutive activation of both HIF1a and HIF2a. As HIF2a is the driver of the disease promoting tumour growth and metastasis, drugs targeting HIF2a have been developed. However, resistance is common, therefore new therapies are needed. Methods: we generated the 786-0 HIF2a knockout (KO) cell line and assessed the HIF2a antagonist PT2385 in several steps of tumour development. RNA sequencing was performed to identify genes differentially expressed between them and a drug screening was used to identify drugs with differential effects on HIF2a-expressing and KO cells. Results: HIF2a KO promoted cell migration, reduced proliferation and clonogenicity, as well as metastasis, whereas PT2385 treatment only inhibited tumour cell invasion. There was a large set of co-ordinately regulated genes, but HIF2a KO cells also had up-regulation of genes related to EMT and downregulation of genes involving cell migration and extracellular matrix. The HIF2a KO increased sensitivity to statins, while PT2385 had no effect. Conclusions: this study shows new pathways that could be targeted combined with PT2385 to enhance its therapeutic effects and delay resistance. Overall design: Sequencing of RNA extracted from 786-0 parental (WT), 786-0 HIF2a KO and 786-0 WT cells treated with 10uM PT2385 under normoxia conditions. 3 replicates per sample. Total of 9 samples.