Although a variety of cancers are initially susceptible to chemotherapy, they eventually develop multi-drug resistance. Anti-tumor agents overcoming resistance and acting through two or more ways offer greater therapeutic benefits over single-mechanism entities. In this study, we report on a new family of bifunctional compounds that, offering the possibility of dual action (drug + radiotherapy combinations), may result in significant clinical benefits. This new family of compounds combines two fragments: the drug fragment is a lapatinib group, which inhibits the tyrosine kinase receptor activity, and an icosahedral boron cluster used as agents for neutron capture therapy (BNCT).

The developed compounds were evaluated in vitro against different tyrosine kinase receptors (TKRs)-expressing tumoral cells, and in vitro–BNCT experiments were performed for two of the most promising hybrids, 19 and 22. We identified hybrid 19 with excellent selectivity to inhibit cell proliferation and ability to induce necrosis/apoptosis of glioblastoma U87 MG cell line. Furthermore, derivative 22, bearing a water-solubility-enhancing moiety, showed moderate inhibition of cell proliferation in both U87 MG and colorectal HT-29 cell lines. Additionally, the HT-29 cells accumulated adequate levels of boron after hybrids 19 and 22 incubations rendering, and after neutron irradiation, higher BNCT-effects than BPA. The attractive profile of developed hybrids makes them interesting agents for combined therapy. 

This publication belongs to the collection of articles invited in the issue on "Biology of Boron Neutron Capture Therapy (BNCT)".

According to Clara Viñas, "the article describes the synthesis, purification, and complete characterization of a family of bifunctional compounds for use in the treatment of brain cancer (malignant glioblastoma) and colon cancer. The compounds have been studied in vitro with glioblastoma tumor cells (U87 MG) and colon cancer (HT-29) and BNCT experiments have been performed in vitro. The results are very good, showing the possibility of its use for the dual treatment of brain cancer".

Closo-Carboranyl- and Metallacarboranyl [1,2,3]triazolyl-Decorated Lapatinib-Scaffold for Cancer Therapy Combining Tyrosine Kinase Inhibition and Boron Neutron Capture Therapy
Marcos Couto*, Catalina Alamón, María Fernanda García, Mariángeles Kovacs, Emiliano Trias, Susana Nievas, Emiliano Pozzi, Paula Curotto, Silvia Thorp, María Alejandra Dagrosa, Francesc Teixidor, Clara Viñas,* and Hugo Cerecetto*
Cells 2020, 9 (6), 1408. 
DOI: 10.3390/cells9061408

Closo-Carboranyl- and Metallacarboranyl [1,2,3]triazolyl-Decorated Lapatinib-Scaffold for Cancer Therapy Combining Tyrosine Kinase Inhibition and Boron Neutron Capture Therapy