Abstract B087: PARK2 expression reduces migration and invasion and deregulates metabolic pathways in ccRCC

PARK2 is an E3-ubiquitin-ligase, which plays an important role in mitophagy, a macroautophagy process that selectively degrades defective mitochondria. The significant downregulation of mRNA and protein levels in clear cell renal cell carcinoma (ccRCC) were shown to be associated with aggressive disease and poor clinical outcome (Toma et al., 2013). The aim of our study was to investigate the role of of PARK2 in ccRCC. First, we transduced the ccRCC cell line 786-O with a PLVX-EF1a-PARK2-IRES-mcherry construct to overexpress PARK2. Subsequently, we performed functional assays, analyzed the mitochondria and mitochondrial respiration, and RNA-Sequencing. While apoptosis, cell cycle and cell proliferation remained unaffected, we found a marked reduction of migration and invasion in PARK2 overexpressing cells compared to wt controls. PARK2 is involved in the degradation of damaged mitochondria during mitophagy, therefore, we investigated the amount of active and total mitochondria and found more active mitochondria in the PARK2 clones. The overall amount of mitochondria was unchanged. To verify the results and get a further insight into the functionality of the mitochondria mitochondrial respiration was analyzed. As expected, the mitochondrial respiration of the PARK2 clones was upregulated. In addition, we observed a general shift towards metabolic upregulation in 786-O cells expressing PARK2. To find specific pathways affected by the expression of PARK2, we performed RNA Sequencing. Several metabolic pathways were deregulated in the cells expressing PARK2 compared to wt controls. We were able to identify several genes being downregulated in transgenic wild type cells that play a role in the epithelial-to-mesenchymal transition underlining our phenotypic findings of invasion and migration. In conclusion, PARK2 has an impact on the aggressiveness of the disease, the health of the mitochondria and effects a deregulation of metabolic pathways. Lately, several groups reported on the connection between migration/invasion and metabolic changes (Kenny et al., 2019; Yizhak et al., 2014; Gaude and Frezza; 2016, Yao et al., 2018) suggesting a potential link between these two events. Our study adds additional proof towards that link, nevertheless, further research needs to be conducted to identify if these two events are indeed interconnected and dependent on each other. Literature Gaude E and Frezza C. Tissue-specific and convergent metabolic transformation of cancer correlates with metastatic potential and patient survival. Nat Commun. 7:13041. 2016. Kenny TC et al. Mitohormesis Primes Tumor Invasion and Metastasis. Cell Rep. 27(8):2292-2303. 2019. Toma MI et al. PARK2 and PACRG are commonly downregulated in clear-cell renal cell carcinoma and are associated with aggressive disease and poor clinical outcome. Genes Chromosomes Cancer. 52(3):265-73. 2013. Yao L, Guo X, Gui Y. Acetyl-CoA Synthetase 2 Promotes Cell Migration and Invasion of Renal Cell Carcinoma by Upregulating Lysosomal Associated Membrane Protein 1 Expression. Cell Physiol Biochem. 45(3):984-992. 2018. Yizhak K et al. A computational study of the Warburg effect identifies metabolic targets inhibiting cancer migration. Mol Syst Biol. 10:744. 2014. Citation Format: Laura K Eser, Lena Arevalo, Glen Kristiansen, Hubert Schorle, Marieta I Toma. PARK2 expression reduces migration and invasion and deregulates metabolic pathways in ccRCC [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B087. doi:10.1158/1535-7163.TARG-19-B087