Journal: Oncogene

Article Title: C1GALT1 high expression is associated with poor survival of patients with pancreatic ductal adenocarcinoma and promotes cell invasiveness through integrin α v

doi: 10.1038/s41388-020-01594-4

Figure Lengend Snippet: A Western blots showing C1GALT1 stable knockdown in HPAF-II and HPAC cells and C1GALT1 overexpression in MIAPaca2 cells. PDAC cells were transfected using lentivirus-mediated C1GALT1 shRNA in pLKO.1 vector (shC1GALT1) compared with its empty vector (shControl) and C1GALT1 was overexpressed using C1GALT1/pcDNA3.1 plasmid (C1GALT1) compared with its empty plasmid (mock). GAPDH was used as an internal loading control. B C1GALT1 knockdown or overexpression did not alter the expression of surface integrins β 1 , α 5 , α 5 β 1 , and α v in HAPF-II and HPAC cells analyzed by flow cytometry. Unstained cells were used as a negative control (-). C Effects of functional blocking antibodies against integrins on PDAC cell invasion. C1GALT1 knockdown HPAF-II and HPAC cells and C1GALT1 overexpressing MIAPaca2 cells were subjected to Matrigel invasion assays. Cells were treated with 10 μg/mL of blocking antibody, as indicated. IgG was used as a control. Invasion of HPAF-II, HPAC, and MIAPaca2 cells was analyzed after 24 and 48 h. Results are presented as mean ± SD of four independent experiments. * p < 0.05; ** p < 0.01; *** p < 0.001 by student’s t test. D Effects of functional blocking antibodies on FAK phosphorylation in PDAC cells using Western blotting. Functional blocking antibody against integrin α v or α 5 was used, as indicated, to treat HPAF-II and HPAC cells for 30 min before seeding to culture plates. IgG was used as a control. GAPDH was used as an internal loading control. E Western blots showing changes in Tn antigens on cell surface integrins α V and α 5 . Cells were surface biotinylated. Plasma Membrane Protein Extraction Kit (Abcam) was used for extraction and purification of plasma membrane proteins from HPAF-II and HPAC cells. VVA pull-down (PD) assays were performed to assess changes in Tn antigens on integrins. Proteins were detected by Western blot (WB) analysis. F A schematic diagram illustrating the proposed mechanism by which C1GALT1 promotes tumor growth and metastasis in pancreatic cancer. C1GALT1 modifies O-glycans on integrins, including α 5 , α v , and β 1 , which leads to altered integrin-FAK signaling. Integrin α v (red color) is proposed to play a critical role in C1GALT1-mediated invasiveness. This pathway is coordinated with other C1GALT1-regulated pathways, such as receptor tyrosine kinases (RTKs) and mucins, to promote tumor growth and metastasis in pancreatic cancer. FN fibronectin, VN vitronectin.

Article Snippet: Antibodies against integrin α v (P3G8), integrin α 2 (CD49b), and integrin α 3 (CD49c) were obtained from Merck KGaA (Darmstadt, Germany).

Techniques: Western Blot, Knockdown, Over Expression, Transfection, shRNA, Plasmid Preparation, Control, Expressing, Flow Cytometry, Negative Control, Functional Assay, Blocking Assay, Phospho-proteomics, Clinical Proteomics, Membrane, Protein Extraction, Extraction, Purification