Anti-Survival Effect of SI306 and Its Derivatives on Human Glioblastoma Cells

Early investigation of a novel SI306 theranostic prodrug for glioblastoma treatment

Glioblastoma multiforme (GBM) is one of the most aggressive malignancies with a high recurrence rate and poor prognosis. Theranostic, combining therapeutic and diagnostic approaches, arises as a successful strategy to improve patient outcomes through personalized medicine. Src is a non-receptor tyrosine kinase (nRTK) whose involvement in GBM has been extensively demonstrated. Our previous research highlighted the effectiveness of the pyrazolo[3,4-d]pyrimidine SI306 and its more soluble prodrug CMP1 as Src inhibitors both in in vitro and in vivo GBM models. In this scenario, we decided to develop a theranostic prodrug of SI306, ProSI-DOTA(68 Ga) 1, which was designed to target GBM cells after hydrolysis and follow-up on the disease's progression and improve the therapy's outcome. First, the corresponding nonradioactive prodrug 2 was tested to evaluate its ADME profile and biological activity. It showed good metabolic stability, no inhibition of CYP3A4, suboptimal aqueous solubility, and slight gastrointestinal and blood-brain barrier passive permeability. Compound 2 exhibited a drastic reduction of cell vitality after 72 h on two different GBM cell lines (GL261 and U87MG). Then, 2 was subjected to complexation with the radionuclide Gallium-68 to give ProSI-DOTA(68 Ga) 1. The cellular uptake of 1 was evaluated on GBM cells, highlighting a slight but significant time-dependent uptake. The data obtained from our preliminary studies reflect the physiochemical properties of 1. The use of an alternative route of administration, such as the intranasal route, could overcome the physiochemical limitations and enhance the pharmacokinetic properties of 1, paving the way for its future development.

Recent advances of small-molecule c-Src inhibitors for potential therapeutic utilities

Proto-oncogene tyrosine-protein kinase Src, also known as c-Src, belongs to the family of non-receptor tyrosine protein kinases (TKs) called Src kinases. It plays a crucial role in cell division, motility, adhesion, and survival in both normal cells and cancer cells by activating various signaling pathways mediated by multiple cytokines. Additionally, c-Src kinase has been implicated in osteoclasts and bone loss diseases mediated by inflammation and osteoporosis. In recent years, remarkable advancements have been achieved in the development of c-Src inhibitors, with several candidates progressing to the clinical stage. This review focuses on the research progress in several areas, including the mechanism of action, drug discovery, combination therapy, and clinical research. By presenting this information, we aim to provide researchers with convenient access to valuable insights and inspire new ideas to expedite future drug discovery programs.