Fig 2: PLAUR is essential for the malignant phenotype of GC cells mediated by TCF7L2. a-b Cell proliferation of MKN45 cells with knockdown of TCF7L2 or control, and re-expression of PLAUR in TCF7L2 depleted cells, as quantified by CCK-8 (a) and EdU (b) assay, respectively. c After GC cells were suspended for 24 h, the anoikis resistance of MKN45 cells with knockdown of TCF7L2 or control and re-expression of PLAUR in TCF7L2 depleted cells were assessed via flow cytometry. d After GC cells were suspended for 24 h, western blot for apoptosis-related proteins in MKN45 cells with the depletion of TCF7L2 or control, or re-expression of PLAUR in TCF7L2 depleted cells. e-f Measurement of cell migration by transwell (e) and wound healing (f) assays using MKN45 cells with depletion of TCF7L2 or control, or re-expression of PLAUR in TCF7L2 depleted cells. * P<0.05, ** P<0.001.

Fig 3: Schematic summary. Mechanistically, TCF7L2 is upregulated in GC and transcriptionally activates PLAUR, which promotes anoikis resistance and metastasis of GC cells.

Fig 4: TCF7L2 promotes transcription of PLAUR in GC. a Representative image of the co-localization of TCF7L2 protein (green) and PLAUR (red) in MKN45 cell lines observed by confocal microscopy. b Representative image of the co-localization of TCF7L2 protein (green) and PLAUR (red) in 15 GC tissues (cohort 1) observed via confocal microscopy; the expression of TCF7L2 and PLAUR was positively correlated via fluorescence quantitative analysis. c-d TCF7L2 has a positive regulatory effect on the expression of PLAUR in GC cells. The effects of TCF7L2 silencing on PLAUR mRNA or protein expression in GC cells as detected by RT-qPCR (c) and western blot (d), respectively. e Motif of the TCF7L2 binding site in the PLAUR promoter, predicted through the JASPAR dataset. f Schematic of the TCF7L2 binding site on the PLAUR promoter. g ChIP-qPCR analysis of TCF7L2 binding to the PLAUR promoter in MKN45 and 293T cell lines. The second position was the most important binding site. e Luciferase activity was determined after mutation of the second TCF7L2 site in the PLAUR promoter in MKN45 and 293T cell lines. The luciferase activity of the wild-type PLAUR promoter was significantly higher than that of mutant PLAUR promoter. Compared with the corresponding control group, * P < 0.001.

Fig 5: High TCF7L2 expression predicts poor prognosis of patients with GC. a Typical images of TCF7L2 protein in GC and adjacent tissues stained by IHC. In GC tissues, TCF7L2 protein was located in the nucleus and cytoplasm; in adjacent tissues, TCF7L2 protein was primarily located in cytoplasm. b Survival curve of 121 GC patients (cohort 2). High TCF7L2 expression correlated with poor prognosis of GC patients. c TCF7L2 protein was quantitatively analyzed via western blot in 10 pairs of fresh GC and adjacent tissues (cohort 3). d Independent prognostic factor for overall survival of 121 patients with GC, shown as a forest plot.