Fig. 7: Pharmacologic inhibition or genetic knockdown of TYK2 promotes breast cancer invasion and metastasis in patient-derived breast tumor xenografts.

a–c Schematic illustrating the isolation of patient-derived organoids, GFP labeling, and orthotopic transplantation of GFP-labeled organoids into the mammary fat pad of NSG mice (Created in BioRender. https://BioRender.com/3be9khp) (a). Fluorescence microscopy images showing GFP expression in patient-derived organoids (b). GFP-labeled patient-derived organoids were orthotopically injected into the mammary fat pad of NSG mice, with GFP-positive tumor cells detected in primary tumors and lungs (c). d–k Schematic of the TYK2 inhibitor treatment protocol: one million GFP-labeled patient-derived xenograft (PIM025) tumor cells were orthotopically injected into the mammary fat pad of female NSG mice, followed by randomization after two weeks and daily oral gavage with vehicle control or the TYK2 inhibitor deucravacitinib for five weeks before endpoint analyses (d). Tumor weight at the experimental endpoint, n = 20 tumor from 10 mice per group (e). Representative images of lung metastases, with GFP-positive metastatic tumor cells shown in green, scale bar, 1 mm (f), and lung metastatic burden quantified as the number of GFP-positive nodules (g) (n = 10 mice per group). Representative images of primary tumor invasion, with arrows indicating GFP-positive invasive tumor cells, scale bar, 2 mm (h), and percentage of primary tumors exhibiting local (mammary gland) or regional (peritoneum) invasion(i) (n = 10 mice per group). Immunohistochemical analysis of TWIST1, scale bar, 50 μm (j) and quantification of nuclear TWIST1 as the percentage of total cells (k) (n = 5 mice per group).l–o qPCR analysis of PIM025 tumors expressing control or TYK2-targeting shRNAs, n = 3 biological replicates (l). Tumor weight at the experimental endpoint, n = 12 tumor from 6 mice per group (m). Representative images of lung metastases, with arrows indicating GFP-positive metastatic tumor cells, scale bar, 1 mm (n), and lung metastatic burden quantified as the number of GFP-positive nodules (o) (n = 5 mice per group). Data are mean ± SEM, ****p < 0.0001; ***p < 0.001; **p < 0.01; *p < 0.05; ns, not significant. Statistical significance was assessed using unpaired two-tailed Student’s t-test with Welch’s correction. Exact P values and source data are provided in the Source Data file.