Discovery of Novel, Potent, and Selective Small-Molecule Menin-Mixed Lineage Leukemia Interaction Inhibitors through Attempting Introduction of Hydrophilic Groups

Menin-MLL protein-protein interaction inhibitors: a patent review (2021-present)

INTRODUCTION

Acute leukemia harboring rearrangement of the Mixed lineage leukemia (MLL) and/or mutation of the nucleophosmin is a type of poorly prognostic and highly malignant leukemia which is extremely difficult to treat. Blocking the protein-protein interaction between Menin and MLL is a strategic approach for treating leukemias, as a new direction for drug discovery. Many biotech and pharmaceutical companies made great efforts to this drug development field, and a large number of small molecular Menin-MLL PPI inhibitors were reported during the recent three years.

AREAS COVERED

This review is to mainly summarize the Menin-MLL PPI inhibitors reported in the recent three years' patents.

EXPERT OPINION

Although the past 12 years have witnessed the progress of the Menin-MLL PPI inhibitors in the treatment of acute leukemia, especially for leukemia harboring rearranged KMT2A and/or mutated NPM1, recent studies showed Menin-MLL PPI inhibitors suffered from new issues such as toxicity, acquired resistance, and homogenization. Therefore, new drug discovery strategies should be considered in advance. The expert opinion was proposed from several aspects, such as developing diverse chemical structures, discovering covalent inhibitors, designing small molecular PROTACs, and targeting the amino acids mutations for next-generation inhibitors.

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.

Discovery of novel pyrrolo[2,3-d]pyrimidines as potent menin-mixed lineage leukemia interaction inhibitors

To interfere the Menin-MLL interaction using small molecular inhibitors has been shown as new treatment of several special hematological malignancies. Herein, a series of Menin-MLL interaction inhibitors with pyrrolo[2,3-d]pyrimidine scaffold were designed, synthesized and evaluated. Among them, compound A6 exhibited potent binding affinity with an IC50 value of 0.38 μM, and strong anti-proliferative activity against MV4-11 cells with an IC50 value of 1.07 μM. Further study showed A6 reduced the transcriptional levels of HOXA9 and MEIS1 genes. Moreover, A6 induced cellular apoptosis, arrested the cell cycle in G0/G1 phase, and reversed the differentiation arrest in a concentration-dependent manner. This study suggested compound A6 was as a novel potent Menin-MLL interaction inhibitor, and it proved that introduction of 4-amino pyrrolo[2,3-d]pyrimidine to occupy the P10 hydrophobic pocket was new idea for design of novel Menin-MLL interaction inhibitors.

Menin orchestrates hepatic glucose and fatty acid uptake via deploying the cellular translocation of SIRT1 and PPARγ

BACKGROUND

Menin is a scaffold protein encoded by the Men1 gene, which interacts with various transcriptional proteins to activate or repress cellular processes and is a key mediator in multiple organs. Both liver-specific and hepatocyte-specific Menin deficiency promotes high-fat diet-induced liver steatosis in mice, as well as insulin resistance and type 2 diabetic phenotype. The potential link between Menin and hepatic metabolism homeostasis may provide new insights into the mechanism of fatty liver disease.

RESULTS

Disturbance of hepatic Menin expression impacts metabolic pathways associated with non-alcoholic fatty liver disease (NAFLD), including the FoxO signaling pathway, which is similar to that observed in both oleic acid-induced fatty hepatocytes model and biopsied fatty liver tissues, but with elevated hepatic Menin expression and inhibited FABP1. Higher levels of Menin facilitate glucose uptake while restraining fatty acid uptake. Menin targets the expression of FABP3/4/5 and also CD36 or GK, PCK by binding to their promoter regions, while recruiting and deploying the cellular localization of PPARγ and SIRT1 in the nucleus and cytoplasm. Accordingly, Menin binds to PPARγ and/or FoxO1 in hepatocytes, and orchestrates hepatic glucose and fatty acid uptake by recruiting SIRT1.

CONCLUSION

Menin plays an orchestration role as a transcriptional activator and/or repressor to target downstream gene expression levels involved in hepatic energy uptake by interacting with the cellular energy sensor SIRT1, PPARγ, and/or FoxO1 and deploying their translocations between the cytoplasm and nucleus, thereby maintaining metabolic homeostasis. These findings provide more evidence suggesting Menin could be targeted for the treatment of hepatic steatosis, NAFLD or metabolic dysfunction-associated fatty liver disease (MAFLD), and even other hepatic diseases.

Design, synthesis and biological evaluation of novel selective PI3Kδ inhibitors containing pyridopyrimidine scaffold

Aim: In our study compounds with pyrido[3,2-d]pyrimidine and pyrido[3,4-d]pyrimidine were designed, synthesized and evaluated for their biological activity against hematologic tumors. Methods: The biological activity of compounds was evaluated by ADP-Glo Luminescence assay, MTT [3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide] assay, western blotting and flow cytometry, respectively. Results: Compounds A1, A5 and A7 containing pyrido[3,2-d]pyrimidine inhibited phosphoinositide 3-kinase-δ (PI3Kδ) at subnanomolar levels and had good δ-isoform selectivity. A1, A5 and A7 showed significant inhibitory effects against SU-DHL-6 cells and effectively inhibited Akt phosphorylation in a good concentration-dependent manner. A7 induced apoptosis and caused cell cycle arrest in SU-DHL-6 cells. Docking studies showed that A1, A5 and A7 bound tightly to PI3Kδ through key hydrogen bonding interactions. Conclusion: This study suggests that employing pyrido[3,2-d]pyrimidine can facilitate the design of novel potent and selective PI3Kδ inhibitors.