Butyrate Suppresses the Proliferation of Colorectal Cancer Cells via Targeting Pyruvate Kinase M2 and Metabolic Reprogramming

Abstract

Butyrate is a short chain fatty acid present in a high concentration in the gut lumen. It has been well documented that butyrate, by serving as an energetic metabolite, promotes the proliferation of normal colonocytes while, by serving as a histone deacetylase inhibitor, epigenetically suppressing the proliferation of cancerous counterparts undergoing the Warburg effect. However, how butyrate interrupts the metabolism of colorectal cancer cells and ultimately leads to the suppression of cell proliferation remains unclear. Here, we employed a metabolomics-proteomics combined approach to explore the link between butyrate-mediated proliferation arrest and cell metabolism. A metabolomics study revealed a remodeled metabolic profile with pronounced accumulation of pyruvate, decreased glycolytic intermediates upstream of pyruvate and reduced levels of nucleotides in butyrate-treated HCT-116 cells. Supplementation of key metabolite intermediates directly affected cancer-cell metabolism and modulated the suppressive effect of butyrate in HCT-116 cells. By a Drug Affinity Responsive Target Stability (DARTS)-based quantitative proteomics approach, we revealed the M2 isoform of a pyruvate kinase, PKM2, as a direct binding target of butyrate. Butyrate activates PKM2 via promoting its dephosphorylation and tetramerization and thereby reprograms the metabolism of colorectal cancer cells, inhibiting the Warburg effect while favoring energetic metabolism. Our study thus provides a mechanistic link between PKM2-induced metabolic remodeling and the antitumorigenic function of butyrate and demonstrates a widely applicable approach to uncovering unknown protein targets for small molecules with biological functions.

Colorectal Cancer and Metabolism

“…This established a mechanism by which aberrant cell metabolism causes an epigenetic shift that contributes to tumorigenesis. A recent study by Li et al demonstrated an additional mechanism to explain the effect of butyrate on CRC cell lines, in which butyrate directly binds to and inhibits PKM2 [195•], a less active isoform of PK that is highly expressed in anabolic cells, including cancer cells, to direct glycolytic intermediates away from the TCA cycle (reviewed in [196]). Finally, fiber-rich diets and the subsequent increase in butyrate have also been shown to attenuate risk factors of CRC, including inflammation, obesity, and insulin resistance (reviewed in [181]).…”

A Review of GC-Based Analysis of Non-Invasive Biomarkers of Colorectal Cancer and Related Pathways

“…Based on the exposed, and according with the reviewed studies, an accumulation of some short-chain fatty acids in CRC is evidenced. In fact, it is demonstrated that butyrate (M46) has its oxidation reduced in CRC tissue, the process is achieved through the down-regulated expression of short chain acyl-CoA dehydrogenase [ 108 , 109 ]. Specifically, butyrate promotes the development of normal cells and inhibits histone deacetylases, thus, making it reasonable to assume that malignant colonocytes perform a metabolic shift to skip butyrate as an energy source [ 109 ].…”

Microbiota Alterations in Gastrointestinal Cancers

“…In both types of esophageal cancers, a strong decrease in commensal microflora can be observed, which may be associated with changes occurring in tissues undergoing carcinogenic transformation. It is worth noting that a decrease occurs in Moryella and Lachnoanaerobaculum umeaense, commensal bacteria that produce butyrate, a short chain fatty acid (SCFA) that has been frequently reported to exhibit anticancer activity [32]. A decrease in Lautropia genus has also been observed in heavy smokers, which can suggest that its decrease is not necessarily a direct result of cancer development [33].…”