The novel choline kinase inhibitor ICL-CCIC-0019 reprograms cellular metabolism and inhibits cancer cell growth

The glycerophospholipid phosphatidylcholine is the most abundant phospholipid species of eukaryotic membranes and essential for structural integrity and signaling function of cell membranes required for cancer cell growth. Inhibition of choline kinase alpha (CHKA), the first committed step to phosphatidylcholine synthesis, by the selective small-molecule ICL-CCIC-0019, potently suppressed growth of a panel of 60 cancer cell lines with median GI50 of 1.12 μM and inhibited tumor xenograft growth in mice. ICL-CCIC-0019 decreased phosphocholine levels and the fraction of labeled choline in lipids, and induced G1 arrest, endoplasmic reticulum stress and apoptosis. Changes in phosphocholine cellular levels following treatment could be detected non-invasively in tumor xenografts by [18F]-fluoromethyl-[1,2–2H4]-choline positron emission tomography. Herein, we reveal a previously unappreciated effect of choline metabolism on mitochondria function. Comparative metabolomics demonstrated that phosphatidylcholine pathway inhibition leads to a metabolically stressed phenotype analogous to mitochondria toxin treatment but without reactive oxygen species activation. Drug treatment decreased mitochondria function with associated reduction of citrate synthase expression and AMPK activation. Glucose and acetate uptake were increased in an attempt to overcome the metabolic stress. This study indicates that choline pathway pharmacological inhibition critically affects the metabolic function of the cell beyond reduced synthesis of phospholipids

Phosphorylation and Stabilization of PIN1 by JNK Promote Intrahepatic Cholangiocarcinoma Growth.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive type of liver cancer in urgent need of treatment options. Aberrant activation of the c-Jun N-terminal kinase (JNK) pathway is a key feature in ICC and an attractive candidate target for its treatment. However, the mechanisms by which constitutive JNK activation promotes ICC growth, and therefore the key downstream effectors of this pathway, remain unknown for their applicability as therapeutic targets. Our aim was to obtain a better mechanistic understanding of the role of JNK signaling in ICC that could open up therapeutic opportunities. APPROACH AND RESULTS: Using loss-of-function and gain-of-function studies in vitro and in vivo, we show that activation of the JNK pathway promotes ICC cell proliferation by affecting the protein stability of peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), a key driver of tumorigenesis. PIN1 is highly expressed in ICC primary tumors, and its expression positively correlates with active JNK. Mechanistically, the JNK kinases directly bind to and phosphorylate PIN1 at Ser115, and this phosphorylation prevents PIN1 mono-ubiquitination at Lys117 and its proteasomal degradation. Moreover, pharmacological inhibition of PIN1 through all-trans retinoic acid, a Food and Drug Administration-approved drug, impairs the growth of both cultured and xenografted ICC cells. CONCLUSIONS: Our findings implicate the JNK-PIN1 regulatory axis as a functionally important determinant for ICC growth, and provide a rationale for therapeutic targeting of JNK activation through PIN1 inhibition

Fluorescence molecular tomography evaluation and applications for in vivo imaging of tumour proliferation

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Strategies in functional proteomics: unveiling the pathways to precision oncology

Personalised strategies in cancer care are required to overcome the therapeutic challenges posed by variability between patients and disease subsets. To this end, enhanced precision tools must be developed to describe the molecular drivers of malignant proliferation. Such tools must also identify druggable targets and biomarkers in order to provide essential information regarding drug development and therapeutic outcome. Here we discuss how proteomics-based approaches provide a set of viable methodologies capable of delivering quantitative information throughout the main stages of personalised oncology and a ratiometric platform that delivers systems-wide methods for drug evaluation

Choline metabolism is an early predictor of EGFR-mediated survival in NSCLC

Oncogenic signalling and metabolic reprograming are hallmarks of tumour progression, yet little is known about the regulatory elements that coordinate their interface. Aberrant choline and phospholipid metabolism are strongly correlated to malignant progression in NSCLC and provide the essential components required by both hallmarks and yet mechanistic links to either remain scarce. Choline kinase alpha (ChoKα) regulates the conversion of choline to phosphocholine and although its regulatory cascade has not been described, it is thought to act in conjuction with EGFR. We used an integrated systems approach and queried whether pharmacoproteomic pathway mapping could identify regulators of the cholinic phenotype. Proteomic and phosphoproteomic Stable isotope labelling by amino acids in cell culture (SILAC) analysis was used to describe the interactome following ChoKα or EGFR inhibition. Bioinformatic analysis was used to identify the significant (Significance-B test) subset of targets for each condition. These subsets were clustered according to GeneOntology, Reactome and KEGG databases and the resulting maps identifed the potential regulators of choline metabolism. Choline uptake, phosphorylation and efflux were further evaluated in vitro in response to erlotinib, cisplatin, pemetrexed and paclitaxel using radio-labelled Choline analogues. Derived metabolites were characterised using radio-HPLC. Uptake was further characterised under hypoxic and nutrient deficient conditions. In vivo, [18F]-D4-Choline PET dynamic imaging was performed following treatment. Pharmacoproteomic analysis revealed a 40% overlap between ChoKα and EGFR inhibition providing direct evidence of the pathways and targets involved in, mostly, biosynthesis. Rapid modulation of the cholinic phenotype was directly dependent on ChoKα activity. Intracellular uptake was induced by nutrient deprivation, hypoxia and reversed through second messenger signalling or growth factor stimulation. Choline uptake within 3 hours of treatment correlated to survival at 72 hours. In vivo, [18F]-D4-Choline tracer kinetics were diagnostic of choline kinase expression and sensitive to treatment. Significant correspondence between ChoKα and EGFR inhibition provided mechanistic evidence that ChoKα and lipid metabolism are effectors of the EGFR signalling cascade in NSCLC. Choline can act as a sensor by synchronizing the survival response via metabolic and signalling reprograming and is thus an early predictor of therapeutic efficiency in vitro and in vivo