Fig. 4: Src-mediated lipin-1 phosphorylation is crucial for breast cancer progression in mice.

a Immunoblots of breast tumour extract from MMTV-PyVT mice at 10, 13 and 16 weeks. Each lane represents proteins from one mouse. b Tumour weights of PyVT;Lpin1^+/+ (n = 37) and PyVT;Lpin1^−/− (n = 34) mice. Experimental mice were killed at 14 weeks of age, and mammary tumours were then removed and weighed. n = 34–37 mice per group. c Multiplicity of lung metastasis. Metastasis multiplicity was determined by H&E staining of 14-week-old PyVT;Lpin1^+/+ (n = 18) and PyVT;Lpin1^−/− (n = 22) mice. d Tumour weights of PyVT;Lpin1^−/− mice infected with adeno-associated viruses (AAV) carrying vector (ctrl), WT-lipin-1 or 3YF-lipin-1. The 6-week-old female Lpin1^−/− mice were anaesthetised and injected with 1 × 10¹¹ genome copies of AAV per fat pad, at 6 weeks post-injection, tumour weights of these mice were measured. n = 10 mice per group. e Schematic diagram of intravenous injection to generate experimental lung metastasis. Lpin1-KO MMTV cell line was isolated from a spontaneous mammary tumour in PyVT;Lpin1^−/− mice. 1 × 10⁵ Lpin1-KO MMTV cells expressing GFP (ctrl), WT-lipin-1 or 3YF-lipin-1 were injected intravenously into 6-week-old FVB/N female mice (n = 19 mice for ctrl or WT-lipin-1 group, n = 18 mice for 3YF-lipin-1 group). f Incidence of lung metastasis. Bars are the percentages of mice with lung metastasis. g Lung metastasis multiplicity was calculated at endpoint. b–d, g Data are mean ± s.e.m.; two-tailed Mann–Whitney test in b, c; one-way ANOVA (repeated measure), followed by Tukey in d; ordinary one-way ANOVA, followed by Tukey in g. ***P < 0.001, N.S. not significant. Source data are provided as a Source Data file.