Fig 2: GAL-1/ LGALS1 promotes the migration and invasion of GC cells in vitro through TGF-β/Smad signaling pathways. (A–D) OE-LGALS1 significantly enhanced the migration capacity of MGC-803 and SGC-7901 cells compared with WC and OE-con. The migration capacity was abolished when the medium contained 10 μM ITD1 (P < 0.01). Magnification: ×40. (E) Transwell assay showing that MGC-803 and SGC-7901 cells increased their invasive ability after transfection with LV-LGALS1-OE, and 10μM ITD1 abolished this increase in invasive ability (n = 3). Magnification: ×200.

Fig 3: Breast cancer tissues express higher level of nuclear Gal-1 than corresponding non-cancerous tissues.Serial sections were used for the immunohistochemical staining of FOXP3 and Gal-1. a Representative immunohistochemical staining for FOXP3 and Gal-1 in normal tissues and primary tumor tissues from breast cancer patient. Scale bars = 100 μm (×10) and 20 μm (×40). b The nuclear Gal-1 expression score was quantified and analyzed in the normal tissues and primary human breast cancer tissues. ***P < 0.001. b Paired t-test

Fig 4: GAL-1/ LGALS1 promotes GC cell metastasis in vivo through the TGF-β/Smad signaling pathway. (A) OE-LGALS1 induced MGC-803 to form subcutaneous xenograft tumors with larger volumes (B) and weighs (C) (expressed as the mean ± SE). * P <0.05, ** P< 0.01, n = 6. (D) OE-LGALS1 increased the levels of TGF-β1 and p-Smad2/3, and induced EMT in the subcutaneous xenograft tumor, ITD1 could inhibit this effect. Metastases were frequent in the (E). (F) Representative images of metastasis (yellow arrows) in the lungs at 50 days after inoculation, and representative images of H&E staining. Original magnification: ×400. (G) Immunostaining showing GAL-1, E-cadherin, vimentin, TGF-β1 and p-Smad2/3 levels in pulmonary metastases. Magnification: ×400.

Fig 5: The FKH domain of FOXP3 is essential for its interaction with Gal-1.a Schematic representation of full-length FOXP3 and corresponding truncated FOXP3 proteins (called F1-60, F61-140, F141-195, F196-230, F231-300, or F301-431). b HEK293T cells were transfected with corresponding Flag-tagged truncated FOXP3 and Gal-1. Co-IP experiment was performed using anti-Flag antibody. c HEK293T cells were transfected with Flag-tagged FOXP3 or Flag-tagged ΔFKH-FOXP3 and Gal-1. Co-IP experiment was performed using anti-Flag antibody. d Three-dimensional structure of FOXP3. The key residues of the FKH domain are shown in red. e A computational docking model shows the superimposition of Gal-1 (yellow) and FOXP3