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Dysregulated activation of the PI3K/AKT/mTOR pathway is crucial in the development of cancer, and disrupting it could potentially lead to cancer suppression, making it a viable strategy for cancer treatment. Here, as a consecutive work of our team, we described the identification and optimization of PI3K/mTOR inhibitors based on triazine scaffold, which exhibited potent PI3K/mTOR inhibitor activity. The systematically structure-activity relationship (SAR) results demonstrated that compound 5nh displayed high efficacy against PI3Kα and mTOR, with the IC 50 values of 0.45 nM and 2.9 nM, respectively. Importantly, compared to the lead compound PKI-587, 5nh demonstrated significant inhibitory activity against non-small-cell lung cancer (NSCLC) cell lines, particularly HCC-827, with a 43-fold increase (3.5 nM vs 150 nM). Additionally, the compound showed effective inhibition against the EGFR-resistant variant HCC-827(GR) cell line. Mechanism validation demonstrated that 5nh significantly interfered with the PI3K/AKT/mTOR signaling pathway in HCC-827 cells. Furthermore, the oral pharmacokinetic properties of 5nh had been observably improved, with AUC 0-t and C max increasing by 13-16 times at a dose of 10 mg/kg in mice. Importantly, the in vivo efficacy study demonstrated that orally treatment of 5nh led to significant tumor growth suppression, with a TGI value of 84.4 %. Collectively, our systematically medicinal chemistry campaigns suggested that 5nh, a novel oral available triazine derivative, held promise as a candidate for therapy of NSCLC by targeting the PI3K/AKT/mTOR cascade., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Phosphatidylinositide-3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) have recently been identified as potential cancer targets. In our work, a new family of quinoline analogues was designed, developed, and evaluated as dual inhibitors of PI3Kδ/mTOR. The preliminary biological activity analysis led to the discovery of the lead compounds 5h and 5e. Compounds 5h and 5e exhibited excellent anti-tumor potency with IC 50 of 0.26 µM and 0.34 µM against Ramos cells, respectively. Importantly, based on the enzymatic activity assay results, compounds 5h and 5e were identified as dual inhibitors of PI3Kδ and mTOR, with IC 50 values of 0.042 µM and 0.056 µM for PI3Kδ and 0.059 µM and 0.073 µM for mTOR, respectively. Furthermore, these compounds showed superior selectivity for blocking PI3Kδ compared to other PI3K isoforms (α, β, and γ), supporting the concept of developing inhibitors that specifically target PI3Kδ/mTOR. The most effective compound 5h was chosen for additional biological testing. At a low dose of 0.5 µM, a western blot investigation confirmed the anticancer effects by inhibiting the PAM cascade, which in turn reduced downstream biomarkers pAkt (Ser473), pAkt (Thr308), and pRPS6 (Ser235/236). Furthermore, it increased apoptosis at the early (10.03 times) and late (17.95 times) stages in the Annexin-V assay as compared to the standard. In addition, the expression of p53, caspase-3, caspase-9, and the Bax/BCl-2 ratio were all significantly increased by compound 5h in the ELISA assay. Based on these results, it appears that 5h may activate the intrinsic apoptosis pathway, which in turn triggers cell death. Furthermore, the anticancer effects could be attributed to the inhibition of PI3Kδ/mTOR, as shown by docking interactions. Lastly, it demonstrated improved in vitro metabolic stability and passed the in silico ADMET/drug-likeness test. This profile recommends 5h for future in vivo PK-PD and efficacy investigations in animal cancer models., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The aberrant activation of the PI3K/mTOR signaling pathway is implicated in various human cancers. Thus, the development of inhibitors targeting mTOR has attracted considerable attention. In this study, we used a structure-based drug design strategy to discover a highly potent and kinase-selective mTOR inhibitor 24 ( PT-88 ), which demonstrated an mTOR inhibitory IC 50 value of 1.2 nM without obvious inhibition against another 195 kinases from the kinase profiling screening. PT-88 displayed selective inhibition against MCF-7 cells (IC 50 : 0.74 μM) with high biosafety against normal cells, in which autophagy induced by mTOR inhibition was implicated. After successful encapsulation in a lipodisc formulation, PT-88 demonstrated favorable pharmacokinetic and biosafety profiles and exerted a large antitumor effect in an MCF-7 subcutaneous bearing nude mice model. Our study shows the discovery of a highly selective mTOR inhibitor using a structure-based drug discovery strategy and provides a promising antitumor candidate for future study and development.

This paper describes the synthesis of some heteroaryl compounds and compositions comprising an effective amount of one or more such compounds and methods for treating or preventing cancer, inflammatory conditions, immunological conditions, metabolic conditions and conditions treatable or preventable by inhibition of a kinase pathway, comprising administering an adequate amount of a heteroaryl compound to a patient in need thereof. These compounds are mTOR/PI3K/Akt pathway inhibitors., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The mTOR and HDAC dual suppression is meaningful for counteracting drug resistance resulted from kinase mutation and bypass mechanisms. Herein, we communicate our recent discovery of a novel structural series of mTOR/HDAC bi-functional inhibitors featuring the pyrazolopyrimidine core via pharmacophore-merging strategy. More than half of them exerted potent dual-target inhibitory activities. In particular, compound 50 exhibited IC 50 values of 0.49 and 0.91 nM against mTOR and HDAC1, respectively, along with remarkably enhanced anti-proliferative activity (IC 50  = 1.74 μM) against MV4-11 cell line than mTOR inhibitor MLN-0128 (IC 50  = 5.84 μM) and HDAC inhibitor SAHA (IC 50  = 8.44 μM). Its intracellular intervention of both mTOR signaling and HDAC was validated by the Western blot analysis. Moreover, as the first disclosed mTOR/HDAC dual inhibitor with selectivity for some specific HDAC subtypes, it has the potential to alleviate the adverse effects resulted from pan-HDAC inhibition. Attributed to its favorable in vitro performance, compound 50 is valuable for further functional investigation as a polypharmacological anti-cancer agent., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A simple and straightforward process for the synthesis of rapamycin peptide conjugates in a regio and chemoselective manner was developed. The methodology comprises the tagging of chemoselective functionalities to rapamycin and peptides which enables the conjugation of free peptides, without protecting the functionality of the side chain amino acids, in high yield and purity. From this methodology, we successfully conjugate free peptides containing up to 15 amino acids. Rapamycin is also conjugated to the peptides known for inhibiting the kinase activity of Akt protein. These conjugates act as dual target inhibitors and inhibit the kinase activity of both mTOR and Akt.