Downregulation of PPA2 expression correlates with poor prognosis of kidney renal clear cell carcinoma

Wenbiao Zhu; Huiming Jiang; Shoucheng Xie; Huanqin Xiao; Qinghua Liu; Nanhui Chen; Pei Wan; Shanming Lu

doi:10.7717/peerj.12086

Downregulation of PPA2 expression correlates with poor prognosis of kidney renal clear cell carcinoma

PeerJ. 2021 Sep 6:9:e12086. doi: 10.7717/peerj.12086. eCollection 2021.

Authors

Wenbiao Zhu^#¹, Huiming Jiang^#², Shoucheng Xie¹, Huanqin Xiao¹, Qinghua Liu¹, Nanhui Chen², Pei Wan², Shanming Lu¹

Affiliations

¹ Department of Pathology, Meizhou People's Hospital, Meizhou, Guangdong, China.
² Department of Urology, Meizhou People's Hospital, Meizhou, Guangdong, China.

^# Contributed equally.

Abstract

Background: Kidney renal clear cell carcinoma (KIRC) is the most common subtype of kidney cancer. Inorganic pyrophosphatase (PPA2) is an enzyme that catalyzes the hydrolysis of pyrophosphate to inorganic phosphate; few studies have reported its significance in cancers. Therefore, we aimed to explore the prognostic value of PPA2 in KIRC.

Methods: PPA2 expression was detected via immunohistochemistry in a tissue chip containing specimens from 150 patients with KIRC. We evaluated the correlation between PPA2 expression, clinicopathological characteristics, and survival. Data from online databases and another cohort (paraffin-embedded specimens from 10 patients with KIRC) were used for external validation.

Results: PPA2 expression was significantly lower in KIRC tissues than in normal renal tissues (p < 0.0001). Low expression of PPA2 was significantly associated with a high histologic grade and poor prognosis. The differential expression of PPA2 was validated at the gene and protein levels. Multivariate Cox regression analysis showed that PPA2 expression was an independent prognostic factor in patients with KIRC. Gene set enrichment analysis suggested that decreased expression of PPA2 might be related to the epithelial-mesenchymal transition in KIRC.

Conclusions: Our study demonstrated that PPA2 is an important energy metabolism-associated biomarker correlated with a favorable prognosis in KIRC.

Keywords: Biomarker; Kidney renal clear cell carcinoma; PPA2; Prognosis.

Grants and funding

This work was supported by the Peiyu Project of Meizhou People’s Hospital (grant no. PY-C2020004) and Medical Science and Technology Research Foundation of Guangdong Province (grant no. B2021143). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.