Discovery and optimization of thieno[3,2-d]pyrimidine derivatives as highly selective inhibitors of cyclin-dependent kinase 7

Design, synthesis and biological evaluation of novel 4-(thieno[3,2-d]pyrimidin-4-yl)morpholine derivatives as potent antitumor agents

A series of 4-(thieno[3,2-d]pyrimidin-4-yl)morpholine derivatives were designed, synthesized and evaluated for their in vitro inhibitory activities against PI3Kα and antiproliferative activities against PC-3, 22RV1, MDA-MB-231 and MDA-MB-453 cancer cell lines. Inhibitory activities against PI3Kα evaluation indicated that some compounds showed excellent PI3Kα activity in vitro, and IC50 values of eight compounds (17c, 17e, 17f, 17h, 17l, 17m, 17o, 17p) were less than 100 nM. The most promising compound 17f (PI3Kα: IC50 = 0.039 μM) showed remarkable antiproliferative against PC-3, 22RV1, MDA-MB-231 and MDA-MB-453 cell lines with IC50 values of 3.48 μM, 1.06 μM, 2.21 μM and 0.93 μM, respectively. Furthermore, 17f effectively reduced p-PI3K protein expression and inhibited the activation of downstream signaling AKT and mTOR proteins in MDA-MB-453 cells. In addition, 17f induced cell apoptosis by down-regulating the expression levels of anti-apoptotic proteins Bcl-XL and Bcl-2 and up-regulating the expression of anti-apoptotic protein BAX, and in MDA-MB-453 cells. All these results indicated the potential of compound 17f to develop as potent anticancer agent.

An insight into the in vivo antitumor therapeutic potential of indole-(fused) pyri(mi)dine hybrids

Cancer can invade and destroy any part of the body, representing a grand social, public health, and economic challenge. Chemotherapy plays a crucial role in cancer treatment, and in recent decades, hundreds of anticancer chemotherapeutics have been introduced. Nevertheless, multidrug resistance and side effects are the main obstacles to successful cancer therapy, highlighting the pressing requirement for the development of new chemotherapeutics to address the above issues. Indole hybrids not only have the potential to surmount drug resistance and adverse effects caused by individual components but also can enhance efficacy and improve pharmacokinetic characteristics since hybrid molecules can concurrently regulate multiple targets within cancer cells. Moreover, numerous indole hybrids exemplified by mobocertinib (indole-pyrimidine hybrid) and osimertinib (indole-quinazoline hybrid) have already been utilized in clinical cancer treatment. Therefore, indole hybrids have emerged as valuable scaffolds for the treatment and eradication of cancer. This review aims to elucidate the current landscape of indole-(fused) pyri(mi)dine hybrids, including indole-quinolines/quinolinones, indole-pyridines, indole-pyrimidines, and indole-fused pyrimidines, with in vivo antitumor therapeutic potential, offering effective candidates for in-depth preclinical evaluations, encompassing articles published from 2021 onward.

Current scenario of fused pyrimidines with in vivo anticancer therapeutic potential

Cancer, characterized by uncontrolled cell growth and metastasis, is responsible for nearly one in six deaths and represents a severe threat to public health worldwide. Chemotherapy can substantially improve the quality of life and survival of patients with cancer, but anticancer chemotherapeutics are associated with a range of adverse effects. Moreover, almost all currently available anticancer chemotherapeutics could develop drug resistance over a period of time of application in cancer patients and ultimately lead to cancer relapse and death in 90% of patients, creating an urgent need to develop new anticancer agents. Fused pyrimidines trait the inextricable part of DNA and RNA and are vital in numerous biological processes. Fused pyrimidines can act on various biological cancer targets and have the potential to address drug resistance. In addition, more than 20 fused pyrimidines have already been approved for clinical treatment of different cancers and occupy a prominent place in the current therapeutic arsenal, revealing that fused pyrimidines are privileged scaffolds for the development of novel anticancer chemotherapeutics. The purpose of this review is to summarize the current scenario of fused pyrimidines with in vivo anticancer therapeutic potential along with their acute toxicity, metabolic profiles as well as pharmacokinetic properties, toxicity and mechanisms of action developed from 2020 to the present to facilitate further rational exploitation of more effective candidates.

Design, synthesis and evaluation of thieno[3,2-d]pyrimidine derivatives as novel potent CDK7 inhibitors

The targeting of cyclin-dependent kinase 7 (CDK7) has become a highly desirable therapeutic approach in the field of oncology due to its dual role in regulating essential biological processes, encompassing cell cycle progression and transcriptional control. We have previously identified a highly selective thieno[3,2-d]pyrimidine-based CDK7 inhibitor with demonstrated efficacy and safety in animal model. In this study, we sought to optimize the thieno[3,2-d]pyrimidine core to discover a novel series of CDK7 inhibitors with improved potency and pharmacokinetic (PK) properties. Through extensive structure-activity relationship (SAR) studies, compound 20 has emerged as the lead candidate due to its potent inhibitory activity against CDK7 and remarkable efficacy on MDA-MB-453 cells, a representative triple negative breast cancer (TNBC) cell line. Furthermore, 20 has demonstrated favorable oral bioavailability and exhibited highly desirable pharmacokinetic (PK) properties, making it a promising lead candidate for further structural optimization.