Overview of epigenetic degraders based on PROTAC, molecular glue, and hydrophobic tagging technologies

Epigenetic pathways play a critical role in the initiation, progression, and metastasis of cancer. Over the past few decades, significant progress has been made in the development of targeted epigenetic modulators (e.g., inhibitors). However, epigenetic inhibitors have faced multiple challenges, including limited clinical efficacy, toxicities, lack of subtype selectivity, and drug resistance. As a result, the design of new epigenetic modulators (e.g., degraders) such as PROTACs, molecular glue, and hydrophobic tagging (HyT) degraders has garnered significant attention from both academia and pharmaceutical industry, and numerous epigenetic degraders have been discovered in the past decade. In this review, we aim to provide an in-depth illustration of new degrading strategies (2017-2023) targeting epigenetic proteins for cancer therapy, focusing on the rational design, pharmacodynamics, pharmacokinetics, clinical status, and crystal structure information of these degraders. Importantly, we also provide deep insights into the potential challenges and corresponding remedies of this approach to drug design and development. Overall, we hope this review will offer a better mechanistic understanding and serve as a useful guide for the development of emerging epigenetic-targeting degraders.

Use of recombinant microRNAs as antimetabolites to inhibit human non-small cell lung cancer

During the development of therapeutic microRNAs (miRNAs or miRs), it is essential to define their pharmacological actions. Rather, miRNA research and therapy mainly use miRNA mimics synthesized in vitro. After experimental screening of unique recombinant miRNAs produced in vivo, three lead antiproliferative miRNAs against human NSCLC cells, miR-22-3p, miR-9-5p, and miR-218-5p, were revealed to target folate metabolism by bioinformatic analyses. Recombinant miR-22-3p, miR-9-5p, and miR-218-5p were shown to regulate key folate metabolic enzymes to inhibit folate metabolism and subsequently alter amino acid metabolome in NSCLC A549 and H1975 cells. Isotope tracing studies further confirmed the disruption of one-carbon transfer from serine to folate metabolites by all three miRNAs, inhibition of glucose uptake by miR-22-3p, and reduction of serine biosynthesis from glucose by miR-9-5p and -218-5p in NSCLC cells. With greater activities to interrupt NSCLC cell respiration, glycolysis, and colony formation than miR-9-5p and -218-5p, recombinant miR-22-3p was effective to reduce tumor growth in two NSCLC patient-derived xenograft mouse models without causing any toxicity. These results establish a common antifolate mechanism and differential actions on glucose uptake and metabolism for three lead anticancer miRNAs as well as antitumor efficacy for miR-22-3p nanomedicine, which shall provide insight into developing antimetabolite RNA therapies.

YAP regulates the liver size during the fasting-refeeding transition in mice

Liver is the central hub regulating energy metabolism during feeding-fasting transition. Evidence suggests that fasting and refeeding induce dynamic changes in liver size, but the underlying mechanisms remain unclear. Yes-associated protein (YAP) is a key regulator of organ size. This study aims to explore the role of YAP in fasting- and refeeding-induced changes in liver size. Here, fasting significantly reduced liver size, which was recovered to the normal level after refeeding. Moreover, hepatocyte size was decreased and hepatocyte proliferation was inhibited after fasting. Conversely, refeeding promoted hepatocyte enlargement and proliferation compared to fasted state. Mechanistically, fasting or refeeding regulated the expression of YAP and its downstream targets, as well as the proliferation-related protein cyclin D1 (CCND1). Furthermore, fasting significantly reduced the liver size in AAV-control mice, which was mitigated in AAV Yap (5SA) mice. Yap overexpression also prevented the effect of fasting on hepatocyte size and proliferation. Besides, the recovery of liver size after refeeding was delayed in AAV Yap shRNA mice. Yap knockdown attenuated refeeding-induced hepatocyte enlargement and proliferation. In summary, this study demonstrated that YAP plays an important role in dynamic changes of liver size during fasting-refeeding transition, which provides new evidence for YAP in regulating liver size under energy stress.

Constitutive androstane receptor induced-hepatomegaly and liver regeneration is partially

The constitutive androstane receptor (CAR, NR3I1) belongs to nuclear receptor superfamily. It was reported that CAR agonist TCPOBOP induces hepatomegaly but the underlying mechanism remains largely unknown. Yes-associated protein (YAP) is a potent regulator of organ size. The aim of this study is to explore the role of YAP in CAR activation-induced hepatomegaly and liver regeneration. TCPOBOP-induced CAR activation on hepatomegaly and liver regeneration was evaluated in wild-type (WT) mice, liver-specific YAP-deficient mice, and partial hepatectomy (PHx) mice. The results demonstrate that TCPOBOP can increase the liver-to-body weight ratio in wild-type mice and PHx mice. Hepatocytes enlargement around central vein (CV) area was observed, meanwhile hepatocytes proliferation was promoted as evidenced by the increased number of KI67

SIRT6 as a key event linking P53 and NRF2 counteracts APAP-induced hepatotoxicity through inhibiting oxidative stress and promoting hepatocyte proliferation

Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury, and its prognosis depends on the balance between hepatocyte death and regeneration. Sirtuin 6 (SIRT6) has been reported to protect against oxidative stress-associated DNA damage. But whether SIRT6 regulates APAP-induced hepatotoxicity remains unclear. In this study, the protein expression of nuclear and total SIRT6 was up-regulated in mice liver at 6 and 48 h following APAP treatment, respectively.

Current trends in drug metabolism and pharmacokinetics

Pharmacokinetics (PK) is the study of the absorption, distribution, metabolism, and excretion (ADME) processes of a drug. Understanding PK properties is essential for drug development and precision medication. In this review we provided an overview of recent research on PK with focus on the following aspects: (1) an update on drug-metabolizing enzymes and transporters in the determination of PK, as well as advances in xenobiotic receptors and noncoding RNAs (ncRNAs) in the modulation of PK, providing new understanding of the transcriptional and posttranscriptional regulatory mechanisms that result in inter-individual variations in pharmacotherapy; (2) current status and trends in assessing drug-drug interactions, especially interactions between drugs and herbs, between drugs and therapeutic biologics, and microbiota-mediated interactions; (3) advances in understanding the effects of diseases on PK, particularly changes in metabolizing enzymes and transporters with disease progression; (4) trends in mathematical modeling including physiologically-based PK modeling and novel animal models such as CRISPR/Cas9-based animal models for DMPK studies; (5) emerging non-classical xenobiotic metabolic pathways and the involvement of novel metabolic enzymes, especially non-P450s. Existing challenges and perspectives on future directions are discussed, and may stimulate the development of new research models, technologies, and strategies towards the development of better drugs and improved clinical practice.

extract (Wuzhi Tablet) protects against chronic-binge and acute alcohol-induced liver injury by regulating the NRF2-ARE pathway in mice

Alcohol abuse leads to alcoholic liver disease and no effective therapy is currently available. Wuzhi Tablet (WZ), a preparation of extract fromthat is a traditional hepato-protective herb, exerted a significant protective effect against acetaminophen-induced liver injury in our recent studies, but whether WZ can alleviate alcohol-induced toxicity remains unclear. This study aimed to investigate the contribution of WZ to alcohol-induced liver injury by using chronic-binge and acute models of alcohol feeding. The activities of ALT and AST in serum were assessed as well as the level of GSH and the activity of SOD in the liver. The expression of CYP2E1 and proteins in the NRF2-ARE signaling pathway including NRF2, GCLC, GCLM, HO-1 were measured, and the effect of WZ on NRF2 transcriptional activity was determined. We found that both models resulted in liver steatosis accompanied by increased transaminase activities, but that liver injury was significantly attenuated by WZ. WZ administration also inhibited CYP2E1 expression induced by alcohol, and elevated the level of GSH and the activity of SOD in the liver. Moreover, the NRF2-ARE signaling pathway was activated by WZ and the target genes were all upregulated. Furthermore, WZ significantly activated NRF2 transcriptional activity. Collectively, our study demonstrates that WZ protected against alcohol-induced liver injury by reducing oxidative stress and improving antioxidant defense, possibly by activating the NRF2-ARE pathway.

Construction and function identification of luciferase reporter gene vectors containing SNPs in NFKBIA gene 3'UTR / 药学学报

This study aims to investigate the function of two SNPs (rs8904C > T and rs696G >A) in 3' untranslated region (3'UTR) of NFKBIA gene by constructing luciferase reporter gene. A patient's genomic DNA with rs8904 CC and rs696 GA genotype was used as the PCR template. Full-length 3'UTR of NFKBIA gene was amplified by different primers. After sequencing validation, these fragments were inserted to the luciferase reporter vector, pGL3-promoter to construct recombinant plasmids containing four kinds of haplotypes, pGL3-rs8904C/rs696G, pGL3-rs8904C/rs696A, pGL3-rs8904T/rs696G and pGL3-rs8904T/rs696A. Then these plasmids were transfected into LS174T cells and the luciferase activity was detected. Compared with pGL3-vector transfected cells (negative control), the luciferase activity of the four kinds of recombinant plasmids was significantly decreased (P A, the luciferase activity of the recombinant plasmids containing A allele (pGL3-rs8904C/rs696A and pGL3-rs8904T/rs696A) was about 45.1% (P T, there were no significant differences in the luciferase activity between the recombinant plasmids containing T allele and those with C allele. Together, the luciferase reporter gene vectors containing SNPs in NFKBIA gene 3'UTR were constructed successfully and rs696G > A could decrease the luciferase activity while rs8904C >T didn't have much effect on the luciferase activity.

Establishment of cell models for PXR, FXR and LXRαagonists high-throughput screening based on reporter gene assay / 中国药理学通报

Aim To develop an in vitro high throughput drug screening system based on reporter gene assay for identification of novel compounds with PXR, FXR and LXRα agonist activity. Methods The expressions of exogenous PXR, FXR and LXRαgene in HEK293, HepG2 and LS174T cells were examined by Real-Time quantity PCR. pSG5-hPXR and pGL3-XREM-CYP3A4, pEGFP-N3-hFXR and EcRE-TK-Luc, pCMX-FLAG-hLXRα and pGL3-XREM-CYP3A4 were cotransfected into cells and the optimal ratio of three plasmids was determined. The dose-response relationship between the positive drug and the fold induction was determined. The specificity of the model was ex-amined, and the repeatability was also determined by Z′ value. Results ① The PXR, FXR and LXRα mRNA expression in HEK293 cell is low among three different cells. ②reporter gene vector and expression plasmid ratio of 1∶ 1, 2∶ 1 and 2∶ 1 were proved to be suitable for highest relative luciferase activity for PXR, FXR or LXRα agonist screening model. ③ The relative luciferase activity was induced by Rif, CDCA or T0901317 in a dose-dependent manner. ④Only Rif, CDCA or T0901317 could significantly increase the relative luciferase activity in PXR,FXR or LXRα agonist screening model, no effect of other nuclear re-ceptors agonist was observed, and the values of Z′-factor for PXR, FXR and LXRαagonist screening model were 0. 58, 0. 66 and 0. 63, respectively. Conclusion An in vitro PXR, FXR and LXRα agonist high-throughput screening models are devel-oped with acceptable specificity and repeatability, and the mod-els can be used to screen PXR, FXR and LXRα agonist.

Induction of UGT1A1 expression by praeruptorin A and praeruptorin C through hCAR pathway / 药学学报

This study is purposed to investigate the effects of praeruptorin A (PA) and praeruptorin C (PC) on UGT1A1 in HepG2 cells through hCAR pathway. PA and PC were incubated with HepG2 cells for 24 h and 48 h, mRNA and protein expressions of UGT1A1 were determined by real-time PCR and Western blotting assays. Additionally, effects of PA and PC on UGT1A1 mRNA and protein expressions were also measured after transient transfection of a specific CAR siRNA for 72 h in HepG2 cells. UGT1A1 mRNA and protein expression levels were significantly increased by PA and PC after incubation for 48 h. Moreover, the mRNA and protein up-regulations of UGT1A1 were attenuated by transient transfection of a specific CAR siRNA, suggesting the induction was mediated by CAR. The results suggest that PA and PC can significantly up-regulate UGT1A1 expression partially via the CAR-mediated pathway.

Advances in the research of pregnane X receptor and constitutive androstane receptor / 药学学报

Nuclear receptors pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are originally characterized as transcription factors regulating many target genes. Recent works have revealed that these nuclear receptors play critical roles in regulating genes that encode drug metabolism enzymes and modulating hepatic energy metabolism, such as down-regulating gluconeogenesis, fatty acid oxidation, and ketogenesis, as well as up-regulating lipogenesis. Studies on PXR and CAR have important implication on drug-drug interaction (DDI) and potential disease treatment targets.

Effects of posttranslational modification on the activity of cytochrome P450: current progress / 药学学报

Regulation of the activity of CYP450 has always been research focus of drug metabolism. The effect of compounds on the mRNA and protein expression level of CYP450 is the main purpose of most of the existing reports. In recent years, the protein modification in the posttranslation level has been found to participate in maintaining the proper function of CYP450, thus effect of posttranslational modification on the enzyme activity has been paid more and more attention. Posttranslational modifications including phosphorylation, nitration, and ubiquitination have been described to regulate the activity of CYP450. In this paper, recent developments in the effects of posttranslational modifications on the activity of CYP450 have been reviewed.

A review on regulation of drug transporters during inflammation / 药学学报

Drug metabolism will change significantly during inflammation, including the reduction of expression and activity of many drug metabolizing enzymes and transporters. Body would release a series of inflammatory cytokines which can regulate drug metabolizing enzymes. Recent studies have revealed that drug transporters are also regulated by the cytokines with obvious species difference. Mechanism studies show that several transcription factors play important roles during the signal pathways of regulation. This review focuses on the progress in the regulation of drug transporters during inflammation.

Effects of Cryptotanshinone on Cytochrome P450 Isoforms in Rat Liver Microsomes / 中药新药与临床药理

Objective To observe the effects of cryptotanshinone (CTS) on cytochrome P450 (CYP) isoforms in the rat liver microsomes. Method The rats were randomized into six groups according to the body weight, 3 rats in each group. CTS groups were treated with CTS at the doses of 20～540 mg/kg per day for 10 days, and the negative control group was treated with 10 mL/kg hydroxylpropyl-β-cyclodextrin solution. The positive group was injected with β-NF(80 mg/kg) intraperitoneally on the 7th day, and all the animals were sacrificed by decapitation on the 10th day after last dose. The liver was got out for the preparation of liver microsomes. The activities of six kinds of CYP isoforms were detected by cocktail in-vitro incubation method. Besides, the expression level of CYP isoforms mRNA and protein in rat liver was analyzed by reverse transcription polymerase chain reaction (RT-PCR) and western-blotting assay, respectively. Results CTS significantly increased the ac-tivity of CYP1A2 in a dose-dependent manner. In CTS groups at the dosages of 20～540 mg/kg, the activity of CYP1A2 was 60 %～430 % higher, CYP1A2 protein expression level was 130 %～320 % higher, and CYP1A2 mRNA expression level was 10 %～150 % higher than that of the negative control group. CTS had no effect on other kinds of CYP isoforms. Conclu-sion CTS can induce hepatic microsome CYP1A2 expression significantly, which indicates potential drug-drug interaction might occurred when CTS is co-administrated with those drugs metabolized by CYP1A2.

Primary hepatocyte culture and its application in drug metabolism and toxicology research and evaluation / 中国药理学通报

For more than 40 years primary hepatocytes culture technique has been utilized extensively for assessing effects of drug on metabolizing enzymes (especially cytochromes P450), drug metabolism, drug-drug interactions, and the mechanisms of cytotoxicity and genotoxicity. Human derived primary hepatocytes reserve the metabolism function and enzyme activity of liver. Therefore, this technique has been widely used as a reliable and efficient tool in the drug and xenobiotics evaluation and screen in vitro. This review focuses on primary culture technique of hepatocytes and its application in drug metabolism and toxicology research and evaluation.

Liver perfusion technique and its applications in drug study / 中国药理学通报

Liver perfusion technique has been used in drug study for many decades. Liver perfusion has outstanding advantages over other techniques, such as isolated hepatocytes, hepatic cell lines, and hepatocyte membrane vesicles.It is an ideal experimental model used in drug metabolism, drug-drug interactions, and pharmacokinetic studies. Liver perfusion technique, its advantages or disadvantages, and its extensive applications have been reviewed.