Abstract 3113: Expression of autophagy- and mitophagy-related genes in clear cell renal cell carcinoma

Abstract Objectives: First objective of this study was to establish primary cell cultures from renal cell carcinoma (RCC). Second objective was to analyze mRNA and protein expression of PINK1, PARK2, PACRG and a-Synuclein, genes involved in cell survival, apoptosis and mitophagy. Methods: Tumor and non-neoplastic tissue from 15 patients undergoing surgery for clear cell renal cell carcinoma (ccRCC, n=9), papillary renal cell carcinoma (pRCC, n=3) as well as three retroperitoneal metastases (two clear cell, one papillary type) were obtained. After tissue digestion and filtration malignant and non-malignant cells were cultivated in two different media in order to establish an optimized cultivation procedure. DNA and RNA were extracted and immunohistochemical analyses (IHC) and qPCR from cultivated cells were performed for VHL and CAIX to verify tumor histotype. RNA was isolated from fresh-frozen primary ccRCC samples and corresponding non-malignant tissues from 50 patients (30 male, 20 female). Expression of PINK1, PARK2, PACRG and a-synuclein was measured by qPCR in the cultivated ccRCC cell lines as well as in the patient samples. Results: All tumor specimens were successfully cultivated to first confluence. Six out of nine ccRCC cell lines and all other tumor specimens could be passaged more than two times. Cultivated RCC cells showed protein expression matching to their tumor of origin in IHC analyses, confirming tumor identity. QPCR demonstrated VHL expression downregulated or lost in all ccRCC cell lines and CA9 highly upregulated in most cases, which is both typical for ccRCC. The mRNA expression of PINK1, PARK2 and PACRG was downregulated in ccRCC cultures as well as in the 50 patient tumors in comparison to normal tissue. A-synuclein expression was highly variable. Conclusions: We successfully established primary cell cultures from various renal tumor entities suitable for further investigation. Loss of PACRG and PARK2 are common events in ccRCC. PACRG and PARK2 might function as tumor suppressors in ccRCC and their loss may be involved in tumor progression as reported before for other tumor entities. Further investigation of PINK1, PARK2 and PACRG might allow new therapeutic approaches. Citation Format: Adrian G. Simon, Joerg Ellinger, Yuri Tolkach, Stefan C. Mueller, Glen Kristiansen, Marieta I. Toma. Expression of autophagy- and mitophagy-related genes in clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3113.