Ab96599

The clinical tissue samples used in this study were histopathologically and clinically diagnosed at Fudan University Shanghai Cancer Center. Prior patient consent and approval from the Institutional Research Ethics Committee were obtained. Paraffin‐embedded tissue slides were deparaffinized in xylene, rehydrated through graded alcohol solutions, blocked in methanol containing 3% hydrogen peroxide, and then incubated with dCK and NRF2 antibodies. The dCK antibody (Abcam, ab96599) was used at a dilution factor of 1:50. The NRF2 antibody (Abcam, ab62352) was diluted to a ratio of 1:100, and then, the slides were rinsed in PBS solution and incubated with secondary antibodies and peroxidase reagent at room temperature. Finally, the slides were incubated with 3,3′‐diaminobenzidine solution at room temperature for 10 minutes and counterstained with haematoxylin. A scoring scale was used to evaluate the percentage of stained cells (0, <10%; 1, 10%‐25%; 2, 25%‐50%; 3, 50%‐75%; 4, >75%) and the staining intensity (0, negative; 1, low; 2, moderate; 3, strong). The overall staining scores were determined by combining the two scores (frequency × intensity). An immunohistochemical score >6 was defined as high expression, whereas a score ≤6 was considered a low expression level.

Mouse and human tissues were fixed with a 10 % formalin solution and embedded in paraffin. 4 μm sections were cut from the tissues and processed for H&E staining and immunohistochemistry using standard protocols as previously described [12 (link),16 (link)]. For immunohistochemistry (IHC) the following antibodies were used: CDA (ab82346, Abcam), DCK (ab96599, Abcam), NT5C1A (Assay Biotechnology Company Inc., C15296), Podoplanin (Axxora LLC; CVL-MAB50714), HA (385911-50UG, Merck Millipore), TYMS (#9045, Cell Signaling). All antibodies were diluted 1:200 in 1 % BSA in TBST. All slides were analyzed by using Fiji imaging software (v 1.52p and 2.14.0/1.54f) as published earlier by Schindelin et al [17 (link)]. For IHC stainings of CDA, DCK, NT5C1A and TYMS, 10 pictures were taken per slide. For stainings of stromal components (HA, Masson's trichrome, pisosirius and podoplanin) 7 pictures were taken per slide using Olympus DP27 camera and the Olympus CellSens Entry 1.12 software.

Masitinib (99% pure) and masitinib-NH₂ (99% pure) were provided by AB Science S.A. Masitinib-NH₂-LC-Biotin was synthesised from masitinib-NH₂ (for synthesis and characterisation, see Supplementary Note 1, Supplementary Fig. 14). DI-39 was synthesised as described previously^{39 (link), 40 (link)}. Protein kinase inhibitors were purchased from Selleckchem. Reagents and substrates for kinetic assays were all purchased from Sigma-Aldrich. Each reagent was obtained as powder and dissolved in H₂O or DMSO and stored as aliquots at −20 °C. Fresh dilutions were prepared for each experiment. Primary antibodies used were a rabbit polyclonal anti-deoxycytidine kinase antibody (ab96599, Abcam, 1:1000), a rabbit polyclonal anti-ERK2 antibody (sc-154, Santa Cruz Biotechnology, 1:2000), a rabbit polyclonal anti-AKT1 antibody (#9272, Cell Signalling Technology, 1:1000), a mouse monoclonal anti-Lyn antibody (610004, BD Biosciences, 1:1000), and a rabbit polyclonal anti-Kit antibody (#3074, Cell Signalling Technology, 1:1000). Primary antibodies were detected using 1:20,000 horseradish peroxidase-conjugated anti-rabbit antibody (Jackson Immunoresearch Laboratories Inc.) or 1:20,000 horseradish peroxidase-conjugated anti-mouse antibody (Dako).