Journal: Scientific Reports
Article Title: Pharmacological inhibition of hypoxia induced acidosis employing a CAIX inhibitor sensitizes gemcitabine resistant PDAC cells
doi: 10.1038/s41598-025-93388-5
Figure Lengend Snippet: ( A ) Inhibition of carbonic anhydrase IX as a surrogate marker of hypoxia, acidosis, and glycolytic metabolism by MZM in PC. Left side of figure indicates hypoxia related upregulation of CAIX and the related effects of this spike. The right of the figure indicates the inhibitory potential of MZM against all the markers studied and therefore all the pathways affected. CFA, colony forming assay, WHA , wound healing assay; PDX, patient derived xenograft, GEM, Gemcitabine. ( B ) Proposed cellular mechanism of action for MZM in PDAC cells. The illustration depicts proposed mechanism of MZM against carbonic anhydrase IX (CAIX) as a potential target in KRAS mutated pancreatic cancer. Under hypoxia, activated CAIX alters pH of intracellular milieu after intake of bicarbonate ions, generation of proton pool, increased uptake of glucose and accumulation of lactate. The altered pH favours stimulation of oncogenic signals by pro survival pathways which cater PC cells to proliferate, survive, invade, and metastasize under acidic environment. Pharmacological inhibition of CAIX by MZM modulates pericellular and intracellular activity owing to hypoxia, acidosis and glycolytic flux and further reduces tumor growth in GEM resistant PC cells. Abbreviations: MZM, Methazolamide; GEM, Gemcitabine, PDAC, Pancreatic ductal adenocarcinoma, NHE1, Sodium/proton exchanger 1; GLUT, Glucose transporter; MCT4, Monocarboxylate transporter 4; PTEN, Phosphatase and tensin homolog; NBC, Sodium bicarbonate cotransporter; IGF, Insulin growth factor; HGF, Hepatocyte growth factor; EGF, Epithelial growth factor; VEGF, Vascular endothelial growth factor; VEGFR, Vascular endothelial growth factor receptor; ATPase, Adenosine triphosphatase; HRE, Hypoxia response element; Hif-1α, Hypoxia inducible factor; MDR1, Multidrug resistance protein 1; RTK, Receptor tyrosine kinase; PHD1/2, Hypoxia-inducible factor prolyl hydroxylase 1/2; VHL, Von Hippel-Lindau Syndrome; LDHA, Lactate dehydrogenase A. Green upside arrow indicates upregulation under hypoxia. Red downside arrow indicates downregulation of effect mediated by MZM. pHe, extracellular pH; pHi, intracellular pH; red star indicates activated KRAS pathway.
Article Snippet: The membranes were incubated with various primary antibodies against different proteins viz, HIF-1α (#610658, BD Biosciences, England, UK), CAIX (#5649, Cell signaling, MA, USA), Ki-67 (#ab15580, Abcam, MA, USA), VEGF (#50661, Cell Signaling, MA, USA), Cyclin D1 (#2922, Cell Signaling, MA, USA) and GAPDH (#MA5-15738, Invitrogen, Canada) overnight followed by 3 washes with PBST.
Techniques: Inhibition, Marker, Wound Healing Assay, Derivative Assay, Activity Assay