Sunitinib and Sorafenib Modulating Antitumor Immunity in Hepatocellular Cancer

Area of Science:

• Oncology
• Immunology
• Pharmacology

Background:

• Sorafenib and sunitinib are FDA-approved tyrosine kinase inhibitors for malignancies.
• Hepatocellular cancer (HCC) remains a significant challenge, necessitating novel therapeutic strategies.
• Chemoimmunotherapy offers a promising avenue for treating HCC by combining chemotherapy with immune system modulation.

Purpose of the Study:

• To investigate the tumoricidal and immune modulatory effects of sorafenib and sunitinib in HCC.
• To compare the efficacy of sorafenib and sunitinib as chemoimmunotherapy agents against HCC.
• To determine if these agents can overcome tumor-induced immune tolerance.

Main Methods:

• In vitro assessment of HCC cell apoptosis and proliferation inhibition.
• In vivo studies using tumor-bearing mice treated with sorafenib or sunitinib.
• Flow cytometry analysis of regulatory T cells (Tregs) and myeloid-derived suppressive cells (MDSCs).
• Assessment of splenic lymphocyte cytokine production (IFN-γ, TNF-α) post-vaccination.
• Combination therapy evaluation involving sunitinib, T-cell transfer, and immunization.

Main Results:

• Both drugs induced equivalent HCC cell apoptosis; sorafenib showed stronger proliferation suppression.
• Sorafenib exhibited greater tumor growth suppression in vivo compared to sunitinib.
• Sunitinib, but not sorafenib, significantly reduced Tregs and MDSCs in tumor-bearing mice.
• Sunitinib treatment enabled splenic lymphocytes to produce IFN-γ and TNF-α upon vaccination, unlike sorafenib.
• Combination therapy with sunitinib enhanced tumor growth suppression beyond sunitinib monotherapy.

Conclusions:

• Sunitinib, unlike sorafenib, prevents tumor-induced immune tolerance and activates anti-tumor immunity in HCC.
• Sunitinib demonstrates potential as a superior chemotherapeutic agent for combination with immunotherapy in HCC treatment.
• These findings support sunitinib's use in developing effective chemoimmunotherapy strategies for HCC.