Glucose Drives Growth Factor–Independent Esophageal Cancer Proliferation via Phosphohistidine–Focal Adhesion Kinase Signaling

Abstract

Background & Aims Most targeted therapies against cancer are designed to block growth factor–stimulated oncogenic growth. However, response rates are low, and resistance to therapy is high. One mechanism might relate to the ability of tumor cells to induce growth factor–independent proliferation (GFIP). This project aims to understand how (1) cancer cells preferentially derive a major growth advantage by using critical metabolic products of glucose, such as phosphoenolpyruvate (PEP), to drive proliferation and (2) esophageal squamous cell carcinoma (ESCC) cells, but not esophageal adenocarcinoma cells, can induce GFIP by using glycolysis to activate phosphohistidine (poHis)-mediated signaling through focal adhesion kinase (FAK). Methods The hypothesis to be tested is that ESCC GFIP induced by glucose is facilitated by PEP-mediated histidine phosphorylation (poHis) of FAK, leading to the possibility that ESCC progression can be targeted by blocking poHis signaling . Biochemical, molecular biological, and in vivo experiments including bromodeoxyuridine/5-ethynyl-2′-deoxyuridine labeling, radioisotope tracing, CRISPR gene editing, and analysis of signaling gene sets in human cancer tissues and xenograft models were performed to define the mechanisms underlying ESCC GFIP. Results Glucose promotes growth factor–independent DNA replication and accumulation of PEP in ESCC cells. PEP is the direct phospho-donor to poHis58-FAK within a known “HG” motif for histidine phosphorylation. Glucose-induced poHis58 promotes growth factor–independent FAK-mediated proliferation. Furthermore, glucose activates phosphatidylinositol-3′-kinase/AKT via poHis58-FAK signaling. Non-phosphorylatable His58A-FAK reduces xenograft growth. Conclusions Glucose induces ESCC, but not esophageal adenocarcinoma GFIP via PEP-His58-FAK-AKT signaling. ESCC progression is controlled by actionable growth factor–independent, glucose-induced pathways that regulate proliferation through novel histidine phosphorylation of FAK.

In vitro selective cytotoxicity of the dietary chalcone cardamonin (CD) on melanoma compared to healthy cells is mediated by apoptosis

“…The cells were incubated in growth factor-free (serum-free), but high glucose (25 mM) and 2 mM L-alanyl-L-glutamine (GlutaMAX TM ) containing DMEM for various time periods (24, 48, 72 h) and, thereafter, the incorporation of BrdU as measure for proliferation evaluated. As earlier published data show that tumor cells and non-cancerous cells proliferate growth-factor independent with high glucose and a stable, viability increasing glutamine source [52–55], those conditions have been used herein for all cell types to avoid artificial data obtained by exogenous growth factors originating from the serum. Furthermore, it was shown that starvation of tumor cells often results in autophagy-activated cell proliferation [56].…”

A non-acidic method using hydroxyapatite and phosphohistidine monoclonal antibodies allows enrichment of phosphopeptides containing non-conventional phosphorylations for mass spectrometry analysis

“…The identities of the pHis proteins we identified suggest that pHis may play a role in mammalian cell signaling [32][33][34] . Indeed, a direct correlation of pHis protein levels with carcinogenesis has recently been reported 30,[35][36][37] . Interestingly, we identified 20 N-phosphate sites on proteins that were reported to be enriched by IAP by Hindupur et al from mTOR-driven hepatocellular carcinoma mouse tumors as potential LHPP substrates, including BCLAF1, which in our studies was found to contain pLys (K391) with a reasonable probability of localization of 79.6%.…”

m6A Methylation Mediates LHPP Acetylation as a Tumour Aerobic Glycolysis Suppressor to Improve the Prognosis of Gastric Cancer

“…The human LHPP gene (NM_022126) is located on chromosome 10 (10q26.13). It is an acidic protein containing 270 amino acids and is a nontransmembrane protein which is mainly located in the cytoplasm and is expressed in most tissues [8][9][10]. Previous studies have found that LHPP is a genetic marker of alcohol dependence and severe depression and is related to mitochondrial dysfunction and chronic oxidative stress [10,11].…”