Journal: Journal of Experimental & Clinical Cancer Research : CR
Article Title: Tumor suppressor SLC9A2 inhibits colorectal cancer metastasis and reverses immunotherapy resistance by suppressing angiogenesis
doi: 10.1186/s13046-025-03422-7
Figure Lengend Snippet: Slc9a2 effectively reverses immune resistance in colorectal cancer by inhibiting angiogenesis. ( A ) Flowchart for the establishment of the MC38-R cell line demonstrating resistance to immunotherapy. MC38 cells that developed acquired resistance to immunotherapy were selected under low-dose PD-1 antibody pressure and designated as MC38-R. ( B ) Subcutaneous tumor models in C57BL/6 mice were constructed using both MC38-S (sensitive) and MC38-R cell lines ( n = 4/group). Subsequent intraperitoneal injection of PD-1 monoclonal antibody was conducted to evaluate the efficacy of immunotherapy based on tumor weight. ( C ) Three mice from each group depicted in Fig. 7B were selected for H&E staining, as well as IHC staining for CD8 and CD31, followed by statistical analysis. ( D ) MC38-R cells were employed to establish subcutaneous tumor models in C57BL/6 mice. Upon reaching a tumor volume of 100 mm³, an SLC9A2 overexpression plasmid was intratumorally injected, accompanied by intraperitoneal administration of anti-PD-1 and oral administration of Bevacizumab. ( E-G ) Following four weeks of MC38-R subcutaneous tumor implantation, the mice were sacrificed, and tumors were dissected for photography and weight measurement ( G ). The volume changes of tumor growth were analyzed for each group ( E ), alongside assessments of body weight variations in the mice ( F ). ( H ) VEGFA levels in tumor tissues from each group of mice were quantified using ELISA, with the control group mean normalized to 1 for statistical analysis and graphical representation. ( I-M ) Tumor tissues depicted in Fig. 7E were embedded in paraffin and subjected to H&E staining ( I ), as well as CD31 ( J ) and CD8 ( K ) immunohistochemistry. Additionally, TUNEL ( L ) and EdU ( M ) staining were performed to assess tumor proliferation and apoptosis. ( N ) Granzyme B (left) and IFNγ (right) levels in tumor tissues from each group of mice were quantified using ELISA, with the control group mean normalized to 1 for statistical analysis and graphical representation. ( O ) Map of the slc9a2 pcDNA plasmid and validation of the transfection efficiency in MC38. ( P ) Western blot analysis was conducted to determine the levels of VEGFA and p-STAT3 Y705 . Data in bar graphs indicate mean ± SEM. * P < 0.05, ** P < 0.01, *** P < 0.001, n.s., not significant. Student’s t test ( B , C ), multi-group analysis of variance ( G , H , J , K , L , M , N )
Article Snippet: The p-STAT3 Y705 inhibitor Stattic (MCE, HY-13818) and the JAK1/2 inhibitor Ruxolitinib (MCE, HY-50856) were utilized in this study.
Techniques: Construct, Injection, Staining, Immunohistochemistry, Over Expression, Plasmid Preparation, Tumor Implantation, Enzyme-linked Immunosorbent Assay, Control, TUNEL Assay, Biomarker Discovery, Transfection, Western Blot