Fig. 4: Low BMI-induced neuronal NPY upregulates lipogenesis via the Y5R/SREBP2/FASN signaling axis to fuel tumor cell growth.
From: Ghrelin-induced neuronal NPY promotes brain metastasis in lung cancer patients with low BMI
A Metabolic GSEA was performed in matched primary lung (n = 30) and brain metastatic (n = 27) tumors (top) and between Y5Rhigh and Y5Rlow brain metastatic lesions (bottom, GSE200563). Gene sets were derived from Gene Ontology (GO:0006635; GO:0006099; GO:0061621; GO:0046949, GO:0006119, GO:0006631)153. B FAO-driven oxygen consumption (OCR) and glycolytic rate (ECAR) were measured in ScrKO and y5rKO CMT167 cells pretreated with or without rNPY (100 nM) (n = 5 independent experiments, unpaired two-tailed t-test). C Representative images (top) and quantification (bottom) of Oil Red O staining showing lipid accumulation in ScrKO and y5rKO lung cancer cells treated with or without rNPY (100 nM, 12 h; Scale bar: 50 μm; n = 5 independent experiments; unpaired two-tailed t-test). D Top: Western blot of SREBP2 and Y5Rhigh-enriched key oncogenic pathways in ScrKO and y5rKO CMT167 cells treated with or without rNPY (100 nM, normalized to GAPDH; n = 3 independent experiments, unpaired two-tailed t-test). Bottom: Band intensity quantification by ImageJ (unpaired two-tailed t-test). E Top: H2030BrM cancer cells treated with or without rNPY (100 nM) and immunoblotted for activated ERK5 and SREBP2, normalized to GAPDH (n = 3 independent experiments, unpaired two-tailed t-test). Lower: Band intensity quantification by ImageJ (unpaired two-tailed t-test). F Pearson correlation between ERK5-SREBP2, p = 0.036; SREBP2-FASN, p = 0.041 and FASN-CPT1, p = 0.047 in lung cancer brain metastatic patients using a proteomic dataset (PXD027259; n = 19; two-tailed)67. G Expression of Srebp2, Fasn and Cpt1a in ScrKO and y5rKO CMT167 cells treated with or without rNPY (100 nM), by qRT-PCR, normalized to β-Actin n (n = 3 independent experiments, unpaired two-tailed t-test). H Top: Cells from panel G were further immunoblotted for Y5R, pERK5 and SREBP2 in the presence or absence of rNPY (100 nM) or ERK5 inhibitor (100 nM each), GAPDH normalized (n = 3 independent experiments, unpaired two-tailed t-test). Bottom: Band intensity quantification by ImageJ (unpaired two-tailed t-test). I Top: LL2 cells were transfected with or without ERK5/SREBP2 expression plasmids or treated with or without SREBP (Fatostatin HBr) or ERK5 inhibitor (ERK5-IN-1), in presence or absence of rNPY (100 nM) were immunoblotted for activated SREBP2 and Y5R, GAPDH normalized (n = 3 independent experiments, unpaired two-tailed t-test). Bottom: Band intensity quantification by ImageJ (unpaired two-tailed t-test). All data are mean ± S.E.M. Source data are provided as a Source Data file.
