Journal: Journal of Translational Medicine
Article Title: MTHFD2 is required for DNA repair and implicated in LUAD radiotherapy resistance
doi: 10.1186/s12967-026-07680-7
Figure Lengend Snippet: MTHFD2 interacts with XRCC6 and controls XRCC6 expression. A Venn diagram illustrating the overlap between MTHFD2-associated proteins identified by LC-MS/MS analysis ( n = 1,247) and curated DNA repair factors (HR/NHEJ pathways). Six candidate interactors are highlighted. B Co-IP validation of MTHFD2-binding partners in H1299 cells using anti-flag antibody. C Co-immunoprecipitation assay detection of MTHFD2, SMC6 and XRCC6 with endogenous MTHFD2 in whole-cell lysates. D Co-immunoprecipitation assay detection of MTHFD2, SMC6 and XRCC6 with endogenous SMC6 and XRCC6 in whole-cell lysates. E Correlation between MTHFD2 and XRCC6 expression levels in radiotherapy-sensitive (case 1) versus radiotherapy-resistant (case 2) LUAD cohorts. Scale bars: 100 μm/25 μm(inset). F XRCC6 protein levels were positively regulated in cells with MTHFD2 deletion or overexpression. G XRCC6 perturbation (knockdown or overexpression) failed to alter MTHFD2 protein abundance. H Co-IP analysis of FLAG-MTHFD2/XRCC6 interaction dynamics in MTHFD2-manipulated LUAD cells (β-tubulin as loading control). I Co-IP confirming interaction specificity: XRCC6 antibody pulls down exogenous MTHFD2 in overexpression models. J in vivo functional correlation: MTHFD2 depletion (shRNA) impairs XRCC6 expression in xenograft tumours post-ionizing radiation treatment, as shown by dual immunofluorescence test. Scale bars: 100 μm/25 μm(inset). Statistical significance determined by two-tailed Student’s t-test ( n = 3, ** p < 0.01)
Article Snippet: Recombinant lentiviral vectors carrying MTHFD2/XRCC6 overexpression constructs (LV-MTHFD2/LV-XRCC6) and short hairpin RNA (shRNA) sequences targeting MTHFD2/XRCC6 (LV-shMTHFD2/LV-shXRCC6) were commercially purchased from GeneChem Co., Ltd (Shanghai, China).
Techniques: Expressing, Liquid Chromatography with Mass Spectroscopy, Co-Immunoprecipitation Assay, Biomarker Discovery, Binding Assay, Over Expression, Knockdown, Quantitative Proteomics, Control, In Vivo, Functional Assay, shRNA, Immunofluorescence, Two Tailed Test