Biomarker Profiling Revealed Carcinoembryonic Antigen as a Target of Artesunate in a Ductal Breast Cancer Patient

Abstract

Background/aim: Patients with metastatic tumors commonly have a poor prognosis. Frequently, patients suffering from progressive tumors have a high willingness for the compassionate use of non-approved medications. One of these medications is the antimalarial drug artesunate (ART) which also showed profound anticancer activity in vitro, in vivo, and in preliminary clinical pilot studies. Herein, we report on the compassionate use of ART in a patient with metastatic breast cancer.

Patients and methods: The clinical course of a Caucasian female who was diagnosed with ductal breast cancer at the age of 33 is described. Tumor markers in the blood have been measured, and tumor-associated protein expression has been determined by immunohistochemistry. Microscale thermophoresis and molecular docking in silico were used to study protein-drug interactions.

Results: The tumor responded to ART administered at doses of 150-300 mg daily, and the patient experienced a stabilization of her disease for 1.5 years. ART treatment caused no or minimal side-effects (headache, dizziness, slight tachycardia, slight stomach upset, slight fatigue). Tumor marker determination in the blood of the patient revealed a reduction of carcinoembryonic antigen (CEA), but not CA 27.29 or CA 15.3 levels. We hypothesized that the reduction of CEA levels might be due to binding of ART to this protein. Microscale thermophoresis with recombinant CEA indeed showed binding of ART to this protein in vitro. This result was verified by molecular docking in silico. Immunohistochemical biomarker profiling and computerbased quantification of biomarker expression in a tumor biopsy revealed strong expression of COX2, GRP78, CD71, GSTP1, and c-MYC but weak or minimal expression of VEGFR, P-glycoprotein, survivin, and LOX1.

Conclusion: Among a panel of tumor-related proteins tested, the interaction with CEA may have contributed to the anticancer activity of ART in this patient. It deserves further investigation whether CEA represents not only a valuable biomarker but also a treatment target. ART might be useful for the individualized treatment of metastatic breast tumors.

Keywords: Cancer; chemotherapy; drug repurposing; individualized therapy; natural products; sesquiterpenoids.