Fig. 10

CYP19A1 inhibitor letrozole facilitates anti-PD-1 therapy in MC38 and CT26 mouse tumor models. A and B Tumor growth curves and tumor weight of C57BL/6 or BALB/c mice injected subcutaneously with MC38 or CT26 colon cells with the treatment of IgG control (IgG), letrozole, anti-PD-1 antibody (α-PD-1) alone or in combination with letrozole (n = 8). C Representative flow staining and frequency of CD107a⁺ CD8⁺ T cells and IFN-γ⁺ CD8⁺ T cells in tumor tissues of indicated groups. D The infiltration level of CD8⁺ T cells in tumor tissues was analyzed by immunohistochemistry. E Intratumoral estradiol level was detected by ELISA. F GPR30 and p-Akt/Akt levels were measured in MC38 and CT26 tumor tissues by western blot. G The expression level of PD-L1 on tumor cells was determined by flow cytometry. H Hypoxia-inducible factor (HIF) -1α level was measured in MC38 and CT26 tumor tissues by western blot. I Tumor perfusion was measured using a laser Doppler analyzer in the MC38 and CT26 tumor model. Scale bar, 2 mm. The quantitative analysis showed the relative levels of tumor perfusion in the tumors. J Immunofluorescence analysis of tumor vessel normalization. Scale bar, 50 μm. n = 5. The values are presented as the mean ± standard error of the mean. ^*, P < 0.05; ^**, P < 0.01 vs. control. ^#, P < 0.05; ^##, P < 0.01 vs. α-PD-1