Calcium Electrochemotherapy for Tumor Eradication and the Potential of High-Frequency Nanosecond Protocols

Calcium electroporation (CaEP) is an innovative approach to treating cancer, involving the internalization of supraphysiological amounts of calcium through electroporation, which leads to cell death. CaEP enables the replacement of chemotherapeutics (e.g., bleomycin). Here, we present a standard microsecond ( mu sCaEP) and novel high-frequency nanosecond protocols for calcium electroporation (nsCaEP) for the elimination of carcinoma tumors in C57BL/6J mice. We show the efficacy of CaEP in eliminating tumors and increasing their survival rates in vivo. The antitumor immune response after the treatment was observed by investigating immune cell populations in tumors, spleens, lymph nodes, and blood, as well as assessing antitumor antibodies. CaEP treatment resulted in an increased percentage of CD4(+) and CD8(+) central memory T cells and decreased splenic myeloid-derived suppressor cells (MDSC). Moreover, increased levels of antitumor IgG antibodies after CaEP treatment were detected. The experimental results demonstrated that the administration of CaEP led to tumor growth delay, increased survival rates, and stimulated immune response, indicating a potential synergistic relationship between CaEP and immunotherapy.

Automated summary

Calcium electroporation (CaEP) is a promising treatment for cancer, as it effectively eliminates tumors and enhances the immune response. This study presents both microsecond and nanosecond protocols for CaEP, demonstrating their efficacy in tumor eradication and improved survival rates in mice. CaEP treatment leads to an increased percentage of CD4(+) and CD8(+) central memory T cells, reduced splenic myeloid-derived suppressor cells, and elevated levels of antitumor antibodies.