Fig 2: Analysis of the prognostic value of GPC2 in patients with COAD and GPC2-related PPI network: (a) postoperative prognostic nomogram for patients with COAD, (b) the calibration curve of the nomogram for predicting the OS at 1, 3, and 5 years, and (c) GPC2-related PPI network. OS: overall survival.

Fig 3: Decreasing GPC2 inhibits proliferation and promotes apoptosis in HCT-8 and SW620 cells: (a and b) after transfection of shNC, shGPC2-1, shGPC-2, and shGPC2-3 in HCT-8 and SW620 cells, the level of GPC2 was detected by RT-PCR (a; n = 3) and (b) Western blotting, (c) MTT assay was used to analyze the effect of silencing GPC2 on cell proliferation (n = 6), (d and f) Flow cytometry was used to analyze the cell proportion of different cell cycles after GPC2 silencing (n = 3), (e and g) Annexin V/7-AAD Apoptosis Kit was used to detect the proportion of apoptosis in HCT-8 and SW620 cells after GPC2 silencing (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.

Fig 4: High transcription levels of GPC2 suggest a poor prognosis in patients with COAD: (a and b) correlation between GPC2 expression and the OS (a; low expression: n = 284; high expression: n = 144) or DFI (b; low expression: n = 126; high expression: n = 55) of total patients with COAD was analyzed using KM analysis, (c–f) the relationship between GPC2 level and patients’ OS (c and e) and DFI (d and f) was analyzed by KM curve based on TNM stage. TNM stage I–II OS: Low expression: n = 131; High expression: n = 110; TNM stage I–II DFI: Low expression: n = 74; High expression: n = 55; TNM stage III–IV OS: Low expression: n = 112; High expression: n = 75; TNM stage III–IV DFI: Low expression: n = 32; High expression: n = 20. (g–l) Comparison of the GPC2 expression in different groups with different living status (g; alive: n = 334; dead: n = 94), disease status (h; No: n = 159; Yes: n = 22), history of colon polyps (i; No: n = 239; Yes: n = 127), TNM stage (j; I: n = 73; II: n = 168; III: n = 126; and IV: n = 61), N status (k; N0: n = 249; N1: n = 102; and N2: n = 77), and T status (l; T1: n = 10; T2: n = 72; T3: n = 296; and T4: n = 49). OS: overall survival, DFI: disease-free interval. NS: not significant, *P < 0.05, **P < 0.01, ***P < 0.001.

Fig 5: Downregulating GPC2 suppresses migration and invasion HCT-8 and SW620 cells: (a and b) the effect of GPC2 on (a) migration or (b) invasion of HCT-8 and SW620 cells was tested using transwell assay (n = 3). ***P < 0.001.