Int J Biol Sci 2022; 18(11):4341-4356. doi:10.7150/ijbs.71134 This issue

Research Paper

Activation of VIPR1 suppresses hepatocellular carcinoma progression by regulating arginine and pyrimidine metabolism

Yaojie Fu1,2, Shanshan Liu1, Robim M. Rodrigues2, Ying Han1, Cao Guo1, Zhanwei Zhu1, Yong He2, Bryan Mackowiak2, Dechun Feng2, Bin Gao2✉, Shan Zeng1✉, Hong Shen1,3✉

1. Department of Oncology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
2. Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA
3. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China

This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/). See http://ivyspring.com/terms for full terms and conditions.
Citation:
Fu Y, Liu S, Rodrigues RM, Han Y, Guo C, Zhu Z, He Y, Mackowiak B, Feng D, Gao B, Zeng S, Shen H. Activation of VIPR1 suppresses hepatocellular carcinoma progression by regulating arginine and pyrimidine metabolism. Int J Biol Sci 2022; 18(11):4341-4356. doi:10.7150/ijbs.71134. Available from https://www.ijbs.com/v18p4341.htm

File import instruction

Abstract

Graphic abstract

Background and aims: Vasoactive intestinal polypeptide type-I receptor (VIPR1) overexpression has been reported in numerous types of malignancies and utilized to develop novel target therapeutics and radiolabeled VIP analogue-based tumor imaging technology, but its role in liver carcinogenesis has not been explored. In the current study, we investigated the role of the VIP/VIPR1 signaling in controlling hepatocellular carcinoma (HCC) progression.

Approach and results: By analyzing clinical samples, we found the expression level of VIPR1 was downregulated in human HCC tissues, which was correlated with advanced clinical stages, tumor growth, recurrence, and poor outcomes of HCC clinically. In vitro and in vivo studies revealed that activation of VIPR1 by VIP markedly inhibited HCC growth and metastasis. Intriguingly, transcriptome sequencing analyses revealed that activation of VIPR1 by VIP regulated arginine biosynthesis. Mechanistical studies in cultured HCC cells demonstrated that VIP treatment partially restored the expression of arginine anabolic key enzyme argininosuccinate synthase (ASS1), and to some extent, inhibited de novo pyrimidine synthetic pathway by downregulating the activation of CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase). VIP treatment upregulated ASS1 and subsequently suppressed CAD phosphorylation in an mTOR/p70S6K signaling dependent manner. Clinically, we found human HCC samples were associated with downregulation of ASS1 but upregulation of CAD phosphorylation, and that VIPR1 levels positively correlated with ASS1 levels and serum levels of urea, the end product of the urea cycle and arginine metabolism in HCC.

Conclusions: Loss of VIPR1 expression in HCC facilitates CAD phosphorylation and tumor progression, and restoration of VIPR1 and treatment with the VIPR1 agonist may be a promising approach for HCC treatment.

Keywords: arginine metabolism, pyrimidine synthesis, VIPR1, ASS1, CAD