A comprehensive review of small molecules targeting PI3K pathway: Exploring the structural development for the treatment of breast cancer

Cancer stands as one of the deadliest diseases, ranking second in terms of its global impact. Despite the presence of numerous compelling theories concerning its origins, none have succeeded in fully elucidating the intricate nature of this ailment. Among the prevailing concerns in today's world, breast cancer proliferation remains a significant issue, particularly affecting females. The abnormal proliferation of the PI3K pathway emerges as a prominent driver of breast cancer, underscoring its role in cellular survival and proliferation. Consequently, targeting this pathway has emerged as a leading strategy in breast cancer therapeutics. Within this context, the present article explores the current landscape of anti-tumour drug development, focusing on structural activity relationships (SAR) in PI3K targeting breast cancer treatment. Notably, certain moieties like triazines, pyrimidine, quinazoline, quinoline, and pyridoxine have been explored as potential PI3K inhibitors for combating breast cancer. Various heterocyclic small molecules are undergoing clinical trials, such as Alpelisib, the first orally available FDA-approved drug targeting PI3K; others include buparlisib, pictilisib, and taselisib, which inhibit class I PI3K. These drugs are used for the treatment of breast cancer but still have various side effects with their high cost. Therefore, the primary goal of this review is to include all current advances in the development of anticancer medicines that target PI3K over-activation in the treatment of breast cancer.