Patients with pancreatic ductal adenocarcinoma (PDAC) face a clinically intractable disease with poor survival rates, attributed to exceptionally high levels of metastasis. Epithelial-to-mesenchymal transition (EMT) is pronounced at inflammatory foci within the tumor; however, the immunological mechanisms promoting tumor dissemination remain unclear. It is well established that tumors exhibit the Warburg effect, a preferential use of glycolysis for energy production, even in the presence of oxygen, to support rapid growth. We hypothesized that the metabolic pathways utilized by tumor-infiltrating macrophages are altered in PDAC, conferring a pro-metastatic phenotype. We generated tumor-conditioned macrophages in vitro, in which human peripheral blood monocytes were cultured with conditioned media generated from normal pancreatic or PDAC cell lines to obtain steady-state and tumor-associated macrophages (TAMs), respectively. Compared with steady-state macrophages, TAMs promoted vascular network formation, augmented extravasation of tumor cells out of blood vessels, and induced higher levels of EMT. TAMs exhibited a pronounced glycolytic signature in a metabolic flux assay, corresponding with elevated glycolytic gene transcript levels. Inhibiting glycolysis in TAMs with a competitive inhibitor to Hexokinase II (HK2), 2-deoxyglucose (2DG), was sufficient to disrupt this pro-metastatic phenotype, reversing the observed increases in TAM-supported angiogenesis, extravasation, and EMT. Our results indicate a key role for metabolic reprogramming of tumor-infiltrating macrophages in PDAC metastasis, and highlight the therapeutic potential of using pharmacologics to modulate these metabolic pathways.

ObjectiveAn unmet need exists for a non-invasive biomarker assay to aid gastric cancer diagnosis. We aimed to develop a serum microRNA (miRNA) panel for identifying patients with all stages of gastric cancer from a high-risk population.DesignWe conducted a three-phase, multicentre study comprising 5248 subjects from Singapore and Korea. Biomarker discovery and verification phases were done through comprehensive serum miRNA profiling and multivariant analysis of 578 miRNA candidates in retrospective cohorts of 682 subjects. A clinical assay was developed and validated in a prospective cohort of 4566 symptomatic subjects who underwent endoscopy. Assay performance was confirmed with histological diagnosis and compared with Helicobacter pylori (HP) serology, serum pepsinogens (PGs), ‘ABC’ method, carcinoembryonic antigen (CEA) and cancer antigen 19–9 (CA19-9). Cost-effectiveness was analysed using a Markov decision model.ResultsWe developed a clinical assay for detection of gastric cancer based on a 12-miRNA biomarker panel. The 12-miRNA panel had area under the curve (AUC)=0.93 (95% CI 0.90 to 0.95) and AUC=0.92 (95% CI 0.88 to 0.96) in the discovery and verification cohorts, respectively. In the prospective study, overall sensitivity was 87.0% (95% CI 79.4% to 92.5%) at specificity of 68.4% (95% CI 67.0% to 69.8%). AUC was 0.848 (95% CI 0.81 to 0.88), higher than HP serology (0.635), PG 1/2 ratio (0.641), PG index (0.576), ABC method (0.647), CEA (0.576) and CA19-9 (0.595). The number needed to screen is 489 annually. It is cost-effective for mass screening relative to current practice (incremental cost-effectiveness ratio=US$44 531/quality-of-life year).ConclusionWe developed and validated a serum 12-miRNA biomarker assay, which may be a cost-effective risk assessment for gastric cancer.Trial registration numberThis study is registered with ClinicalTrials.gov (Registration number: NCT04329299).

Background:To investigate the involvement of HEXIM1 in the p53 signaling pathway, we examine the functional connection between HEXIM1 and p53. Results: HEXIM1 directly interacts with p53 and enhances the protein stability of p53. Conclusion: HEXIM1 is a novel regulator of p53. Significance: Our results reveal a new function of HEXIM1 in regulating the protein stability and induction of p53.