Captopril, a Renin-Angiotensin System Inhibitor, Attenuates Tumour Progression in the Regenerating Liver Following Partial Hepatectomy.

ABSTRACT: (1) Liver regeneration following partial hepatectomy for colorectal liver metastasis (CRLM) has been linked to tumour recurrence. Inhibition of the renin-angiotensin system (RASi) attenuates CRLM growth in the non-regenerating liver. This study investigates whether RASi exerts an antitumour effect within the regenerating liver following partial hepatectomy for CRLM and examines RASi-induced changes in the tumour immune microenvironment; (2) CRLM in mice was induced via intrasplenic injection of mouse colorectal tumour cells, followed by splenectomy on Day 0. Mice were treated with RASi captopril (250 mg/kg/day), or saline (control) from Day 4 to Day 16 (endpoint) and underwent 70% partial hepatectomy on Day 7. Liver and tumour samples were characterised by flow cytometry and immunofluorescence; (3) captopril treatment reduced tumour burden in mice following partial hepatectomy (p < 0.01). Captopril treatment reduced populations of myeloid-derived suppressor cells (MDSCs) (CD11b⁺Ly6C^Hi&nbsp;p < 0.05, CD11b⁺Ly6C^Lo&nbsp;p < 0.01) and increased PD-1 expression on infiltrating hepatic tissue-resident memory (T_RM)-like CD8⁺ (p < 0.001) and double-negative (CD4^-CD8^-; p < 0.001) T cells; (4) RASi reduced CRLM growth in the regenerating liver and altered immune cell composition by reducing populations of immunosuppressive MDSCs and boosting populations of PD-1⁺ hepatic T_RMs. Thus, RASi should be explored as an adjunct therapy for patients undergoing partial hepatectomy for CRLM.

SUBMITTER: Riddiough GE 

PROVIDER: S-EPMC9105412 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature