Abstract 5740: Aberration of (pro)renin receptor induces genomic instablity in human pancreatic ductal epithelial cells
Authors: Shibayama Yuki , Yasuda Jun , Yamazaki Daisuke , Rahman Asadur , Yachida Shinichi , Nishiyama Akira 
Published: July 2017

Background: We have recently shown the potential contribution of (pro)renin receptor ((P)RR) to tumorigenesis of pancreatic ductal adenocarcinoma (PDAC) through an activation of Wnt/β-catenin signaling pathway (Sci. Rep., 2015). We also found that significant (P)RR expression was synchronized with an appearance of atypical nuclei in PanIN-2 of PDAC tissues. Furthermore, (P)RR knockdown reduced a total of DNA amount in human PDAC cell lines. Based on our findings, we have hypothesized that an aberration of (P)RR leads to a failure of genome homeostasis. Accordingly, we explored whether an aberrant expression of (P)RR induces genomic instability in human pancreatic ductal epithelial (HPDE) cells which are capable of developing to the PDAC.

Methods: HPDE cells transfected by episomal vector inserted with ATP6ap2 encoding (P)RR were established. HPDE cells transfected by vector without the insertion of ATP6ap2 was noted as Mock. We also performed a comet assay to evaluate the defects of DNA repair capacity, flow-FISH to measure the length of telomere and western blotting to confirm the activation of DNA damage pathway by measuring protein levels of γ- H2AX and p53. Then, comparative analyses of human whole genome in Mock- expressing and (P)RR-expressing HPDE cells were examined. Furthermore, we implanted 14-passage HPDE cells expressed by either Mock or (P)RR into the renal subcapsules of immunodeficient mice to investigate whether (P)RR-expressing HPDE cells show a precancerous status in vivo.

Results: (P)RR overexpression led to inactivation of γ-H2AX and p53 as the components of DNA damage pathway, which were associated with a disappearance of comet tail and shorten telomere length. Substantial structural variations, e.g., inter- and intra- chromosomal translocations throughout all the chromosomes were observed in HPDE cells expressed by (P)RR under the analysis by BreakDancer. Analyses with Bcftool showed that the number of all the somatic mutations was approximately 2-fold greater in HPDE cells expressed by (P)RR than those expressed by Mock (Mock: 124,579 vs. (P)RR: 239,080). (P)RR overexpression also significantly increased the number of somatic mutations in several genes which were commonly detected in PDAC tissues. The area occupied by (P)RR-expressing HPDE cell population remarkably expanded after the implantation to renal subcapsules of all the immunodeficient mice. However, there were no KRAS 12 codon mutations which are prevalent in PDAC patients.

Conclusion: We have demonstrated that (P)RR overexpression induces genomic instability on global genome level in HPDE cells. These data are consistent with our hypothesis that (P)RR is essentially involved in the early carcinogenesis of PDAC.

Citation Format: Yuki Shibayama, Jun Yasuda, Daisuke Yamazaki, Asadur Rahman, Shinichi Yachida, Akira Nishiyama. Aberration of (pro)renin receptor induces genomic instablity in human pancreatic ductal epithelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5740. doi:10.1158/1538-7445.AM2017-5740