Glutamic-pyruvic transaminase 1 deficiency-mediated metabolic reprogramming facilitates colorectal adenoma-carcinoma progression.

Abstract

The tumorigenesis of colorectal cancer (CRC) often follows the normal-adenoma-carcinoma (N-A-C) sequence. However, the molecular mechanisms underlying colorectal adenoma carcinogenesis remain largely unknown. Here, we analyzed transcriptomic profile changes in normal, advanced adenoma, and carcinoma tissues from patients with CRC, revealing that glutamic-pyruvic transaminase 1 (<i>GPT1</i>) in colorectal tissues was down-regulated during the N-A-C process and correlated with poor CRC prognosis. Mechanistically, <i>GPT1</i> was transcriptionally activated by Krüppel-like factor 4 (KLF4). GPT1 reprogrammed metabolism and suppressed CRC tumorigenesis in cells and mouse models not only through enzyme-dependent α-ketoglutarate (α-KG) production and WNT signaling inhibition but also through enzyme-independent disruption of the folate cycle through binding with methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L). Furthermore, we identified poliumoside as a GPT1 activator that restrained CRC progression in cells, patient-derived CRC organoids, and patient-derived xenograft (PDX) models of CRC. Our study uncovers a role for GPT1 in CRC tumorigenesis and shows that poliumoside is a potential drug for the prevention and treatment of CRC.