Anti-tumor effect and immune-related mechanism study of compound aluminum sulfate injection in transplanted tumor-bearing mice

Abstract

This study investigates the antitumor and immunomodulatory effects of compound aluminum sulfate (CAS) solution in murine melanoma models. Using syngeneic B16-F10 and B16-OVA tumor models, we demonstrate that intratumoral CAS injection significantly inhibits primary tumor growth and lung metastasis. Flow cytometry analysis reveals that CAS treatment increases splenic populations of CD3⁺CD8⁺ cytotoxic T cells, CD3⁺CD44⁺ memory T cells, and NK cells, while enhancing CD8⁺ T cell infiltration in tumor tissue. ELISA results show elevated levels of pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-2) in splenic culture supernatants and serum following CAS administration. Immunofluorescence staining confirms increased expression of CD8 and IFN-γ proteins in tumor tissues of CAS-treated mice. Results indicate that CAS exerts its antitumor effects through direct cytotoxicity and by modulating both systemic and local immune responses. The dual action of CAS, which combines tumor necrosis with immunostimulation, positions it as a promising therapeutic agent for cancer treatment. This study offers valuable insights into the mechanisms underlying CAS's action and underscores its potential clinical applications in oncology.

Keywords: anti-tumor effect; compound aluminum sulfate injection; immunomodulator; melanoma; metastasis.

Figure 1

Effect of compound aluminum sulfate injection on tumor volume and tumor weight in transplanted melanoma mice. (A) Representative images of tumors excised from control and CAS-treated mice. (B) Quantitative analysis of tumor volume in control and CAS groups, measured in cubic millimeters (mm³). (C) Quantitative analysis of tumor weight in control and CAS groups, measured in grams (g). Data are presented as mean ± standard deviation (SD). ***P<0.001.

Figure 2

Compound aluminum sulfate injection inhibits hematogenous pulmonary metastasis of melanoma in mice. (A) CT images displaying axial, coronal, and sagittal cross-sections of lung tissues from mice in the control group and the CAS group. (B) Representative gross morphology of lungs from both the control group and the CAS group. (C) Histopathological examination of lung tissue sections stained with hematoxylin and eosin (HE) from the control and CAS-treated groups, showing differences in metastatic foci. Higher magnification images are included to highlight details of the metastatic lesions, n = 6 per group.

Figure 3

The effect of compound aluminum sulfate (CAS) solution on the expression of immune cells in mouse spleen. The flow cytometry results are shown for the normal group (Blank), the tumor-bearing model control group (Control), and the drug administration group (CAS) from left to right. The flow cytometry plots (A, C, E, G, I, K) and corresponding quantification graphs (B, D, F, H, J, L) show the percentages of specific immune cell populations in the spleen tissue of different groups. (A, B) CD3⁺CD4⁺ Helper T cells and CD3⁺CD8⁺ Cytotoxic T cells; (C, D) CD3⁺CD44 ⁺ memory T cells; (E, F) Natural killer cells (CD3^-NK1.1⁺); (G, H) myeloid derived suppressor cells (CD11b⁺Gr-1⁺); (I, J) M1 macrophages (F4/80⁺CD86⁺); (K, L) M2 macrophages (F4/80⁺CD206⁺). N=5 per group. *P<0.05; **P<0.01; ***P<0.001.

Figure 4

The effect of compound aluminum sulfate (CAS) solution on the expression of immune cells in mouse tumor tissue. The flow cytometry results are shown for the tumor-bearing model control group (Control), and the drug administration group (CAS) from left to right. The flow cytometry plots (A, C, E, G, I, K) and corresponding quantification graphs (B, D, F, H, J, L) show the percentages of specific immune cell populations in the tumor tissue of different groups. (A, B) CD3⁺CD4⁺ Helper T cells and CD3⁺CD8⁺ Cytotoxic T cells; (C, D) CD3⁺CD44 ⁺ memory T cells; (E, F) Natural killer cells (CD3^-NK1.1⁺); (G, H) myeloid derived suppressor cells (CD11b⁺Gr-1⁺); (I, J) M1 macrophages (F4/80⁺CD86⁺); (K, L) M2 macrophages (F4/80⁺CD206⁺). N=5 per group. *P<0.05; **P<0.01; ***P<0.001.

Figure 5

Cytokine expression in splenic culture supernatant and in serum. (A-G) Cytokine levels in splenic culture supernatant. (A) IFN-γ, (B) TNF-α, (C) TGF-β, (D) IL-2, (E) IL-4, (F) IL-10, and (G) IL-12. (H-N) Serum cytokine levels. (H) IFN-γ, (I) TNF-α, (J) TGF-β, (K) IL-2, (L) IL-4, (M) IL-10, and (N) IL-12. Data are presented for the blank group (Blank), tumor-bearing model control group (Control), and drug injection group (CAS). *P<0.05, **P<0.01, ***P<0.001.

Figure 6

Expression of CD8 and IFN-γ proteins in tumor tissues of control and CAS treatment group (40× and 200×).