ABC Family Transporters

Thyroid transcriptomic profiling reveals the differential regulation of lncRNA and mRNA related to prolificacy in Small Tail Han sheep with FecB++ genotype

The thyroid gland is an important endocrine gland in animals, which mainly secretes thyroid hormones and acts on various organs of the body. Long-chain non-coding RNA (lncRNA) plays an important role in animal reproduction. However, there is still a lack of understanding of their expression patterns and potential roles in the thyroid of Small Tail Han (STH) sheep. In this study, RNA-seq was used to examine the transcriptome expression patterns of lncRNAs and mRNAs in the follicular phase (ww_FT) and luteal phase (ww_LT) in FecB++ genotype STH Sheep. A total of 17,217 lncRNAs and 39,112 mRNAs were identified including 96 differentially expressed lncRNAs (DELs) and 1054 differentially expressed mRNAs (DEGs). Functional analysis of genes with significant differences in expression level showed that these genes could be enriched in Ras signalling pathway, hedgehog (HH) signalling pathway, ATP-binding cassette (ABC) transporters and other signalling pathways related to animal reproduction. In addition, through correlation analysis for lncRNA-mRNA co-expression and network construction, we found that LNC_009115 and LNC_005796 trans target NIK-related kinase (NRK) and poly(A)-specific ribonuclease (PARN). LNC_007189 and LNC_002045 trans target progesterone-induced blocking factor 1 (PIBF1), LNC_009013 trans targets small mothers against decapentaplegic (SMAD1) are related to animal reproduction. These genes add new resources for elucidating the regulatory mechanisms of reproduction in sheep with different reproductive cycles of the FecB++ genotype STH sheep.

Molecular detection of lacrimal apparatus and ocular surface - related ABC transporter genes

The ocular system is in constant interaction with the environment and with numerous pathogens. The ATP-binding cassette (ABC) transporters represent one of the largest groups among the transmembrane proteins. Their relevance has been demonstrated for their defense function against biotic and abiotic stress factors, for metabolic processes in tumors and for their importance in the development of resistance to drugs. The aim of this study was to analyze which ABC transporters are expressed at the ocular surface and in the human lacrimal apparatus. Using RT-PCR, all ABC transporters known to date in humans were examined in tissue samples from human cornea, conjunctiva, meibomian glands and lacrimal glands. The RT-PCR analyses revealed the presence of all ABC transporters in the samples examined, although the results for some of the 48 transporters known in human and analyzed were different in the various tissues. The present results provide information on the expression of ABC transporters at the mRNA level on the ocular surface and in the lacrimal system. Their detection forms the basis for follow-up studies at the protein level, which will provide more information about their physiological significance at the ocular surface and in the lacrimal system and which may explain pathological effects such as drug resistance.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

Purpurogallin carboxylic acid exhibits synergistic effects with 5‑fluorouracil on liver cancer cells in vitro by targeting ABCG2

Purpurogallin carboxylic acid (PCA) is a natural phenol compound derived from Macleaya microcarpa (Maxim.) Fedde, which exerts particular antioxidant and anti-inflammatory capacities. However, the effects and mechanisms of PCA on liver cancer cells remain unknown. Therefore, network pharmacology and computer virtual docking were used to identify the target-proteins of PCA. In addition, surface plasmon resonance, protease activity and rhodamine excretion assays were carried out to evaluate the effects of PCA on the activity of ATP binding cassette subfamily G member 2 (ABCG2). The synergistic effects of PCA and 5-fluorouracil (5-FU) on liver cancer cell proliferation, cell cycle arrest, colony formation and spheroid formation abilities in vitro were determined by Cell Counting Kit-8 (CCK-8) assay, flow cytometry, western blot analysis, colony formation and spheroid formation assays, respectively. ABCG2 was identified as a potential target of PCA, with a high docking score. The equilibrium dissociation constant of PCA for ABCG2 protein was 1.84 µM, while the median inhibitory concentration of this protein was 3.09 µM. In addition, the results demonstrated that PCA could significantly reduce the drug efflux capacity of liver cancer cells. CCK-8 assays revealed that liver cancer cell treatment with 10 µM PCA and 10 µM 5-FU exhibited the most potent synergistic effects on liver cancer cell proliferation at 48 h. Additionally, cell co-treatment with PCA and 5-FU also significantly attenuated the colony and spheroid formation abilities of liver cancer cells in vitro, while it promoted their arrest at the G1 phase of the cell cycle. Furthermore, ABCG2 silencing in liver cancer cells notably abrogated the synergistic effects of PCA and 5-FU. In conclusion, the present study demonstrated that PCA exhibited synergistic effects with 5-FU on liver cancer cells in vitro via targeting ABCG2. Therefore, PCA combined with 5-FU may be a potential strategy for liver cancer therapy.

The Anthraquinone Derivative C2 Enhances Oxaliplatin-Induced Cell Death and Triggers Autophagy via the PI3K/AKT/mTOR Pathway

Chemotherapy resistance in cancer is an essential factor leading to high mortality rates. Tumor multidrug resistance arises as a result of the autophagy process. Our previous study found that compound 1-nitro-2 acyl anthraquinone-leucine (C2) exhibited excellent anti-colorectal cancer (CRC) activity involving autophagy and apoptosis-related proteins, whereas its underlying mechanism remains unclear. A notable aspect of this study is how C2 overcomes the multidrug susceptibility of HCT116/L-OHP, a colon cancer cell line that is resistant to both in vitro and in vivo oxaliplatin (trans-/-diaminocyclohexane oxalatoplatinum; L-OHP). In a xenograft tumor mouse model, we discovered that the mixture of C2 and L-OHP reversed the resistance of HCT116/L-OHP cells to L-OHP and inhibited tumor growth; furthermore, C2 down-regulated the gene expression levels of P-gp and BCRP and decreased P-gp's drug efflux activity. It is important to note that while C2 re-sensitized the HCT116/L-OHP cells to L-OHP for apoptosis, it also triggered a protective autophagic pathway. The expression levels of cleaved caspase-3 and Beclin 1 steadily rose. Expression of PI3K, phosphorylated AKT, and mTOR were decreased, while p53 increased. We demonstrated that the anthraquinone derivative C2 acts as an L-OHP sensitizer and reverses resistance to L-OHP in HCT116/L-OHP cells. It suggests that C2 can induce autophagy in HCT116/L-OHP cells by mediating p53 and the PI3K/AKT/mTOR signaling pathway.

Ovary metabolome and cecal microbiota changes in aged laying hens supplemented with vitamin E

This study was aimed to evaluate the effect of vitamin E (VE) on laying performance, VE deposition, antioxidant capacity, immunity, follicle development, estrogen secretion, ovary metabolome, and cecal microbiota of laying hens. One hundred and twenty XinYang Black-Feathered laying hens (70 wk old) were randomly assigned to 2 groups (6 replicates of 20 birds), and fed a basal diet (containing 20 mg/kg VE, control (CON) group) and a basal diet supplemented with 20 mg/kg VE (VE group). The experiment lasted for 10 wk. Results showed that VE supplementation increased laying performance, antioxidant capacity, and immunity, as evidenced by increased (P < 0.05) performance (laying rate), antioxidant (glutathione peroxidase, total superoxide dismutase, total antioxidant capacity, and catalase) and immune (immunoglobulins) parameters, and decreased (P < 0.05) feed/egg ratio and malondialdehyde. Meanwhile, VE group had higher (P < 0.05) pregrade follicles, ovary index and serum estrogen levels than CON group. 16S rRNA sequencing showed that VE supplementation altered the cecal microbiota composition by increasing Bacteroides, Rikenellaceae_RC9_gut_group, Prevotellaceae_UCG-001 and Megamonas abundances and reducing Christensenellaceae_R-7_group abundance (at genus level), which are mainly associated with the production of short-chain fatty acids. Metabolomic profiling of the ovary revealed that the major metabolites altered by VE supplementation were mainly related to follicle development, estrogen secretion, anti-inflammatory, antioxidant, phototransduction, bile acid synthesis, and nutrient transport. Furthermore, changes in cecal microbiota (at genus level) and ovary metabolites were highly correlated with laying performance, antioxidant, and immune parameters. In summary, VE contributed to the laying performance of aged laying hens by enhancing antioxidant, immune, and ovarian functions, promoting follicle development and estrogen secretion, and regulating gut microbiota and ovary metabolites. These findings will provide a new perspective on the mechanisms of egg production in aged poultry ovaries.

The role of ATP-binding cassette subfamily G member 1 in tumor progression

BACKGROUND

ATP-binding cassette subfamily G member 1 is mostly known as a transporter for intracellular cholesterol efflux, and a number of studies indicate that ABCG1 also functions actively in tumor initiation and progression. This review aimed to provide an overall review of how ABCG1 acts in tumor progression.

METHOD

A comprehensive searching about ABCG1 and tumor was conducted up to November 2023 using proper keywords through databases including PubMed and Web of Science.

RESULT

Overall, ABCG1 plays a crucial role in the development of multiple tumorigenesis. ABCG1 enhances tumor-promoting ability through conferring stem-like properties to cancer cells and mediates chemoresistance in multiple cancers. Additionally, ABCG1 may act as a kinase to phosphorylate downstream molecules and induces tumor growth. In tumor microenvironment, ABCG1 plays a substantial role in immunity response through macrophages to create a tumor-favoring circumstance.

CONCLUSION

High expression of ABCG1 is usually associated with poor prognosis, which means ABCG1 may be a potential biomarker for early diagnosis and prognosis of various cancers. ABCG1-targeted therapy may provide a novel treatment for cancer patients.

Rapid P-TEFb-dependent transcriptional reorganization underpins the glioma adaptive response to radiotherapy

Dynamic regulation of gene expression is fundamental for cellular adaptation to exogenous stressors. P-TEFb-mediated pause-release of RNA polymerase II (Pol II) is a conserved regulatory mechanism for synchronous transcriptional induction in response to heat shock, but this pro-survival role has not been examined in the applied context of cancer therapy. Using model systems of pediatric high-grade glioma, we show that rapid genome-wide reorganization of active chromatin facilitates P-TEFb-mediated nascent transcriptional induction within hours of exposure to therapeutic ionizing radiation. Concurrent inhibition of P-TEFb disrupts this chromatin reorganization and blunts transcriptional induction, abrogating key adaptive programs such as DNA damage repair and cell cycle regulation. This combination demonstrates a potent, synergistic therapeutic potential agnostic of glioma subtype, leading to a marked induction of tumor cell apoptosis and prolongation of xenograft survival. These studies reveal a central role for P-TEFb underpinning the early adaptive response to radiotherapy, opening avenues for combinatorial treatment in these lethal malignancies.

Study on the Effect of Pharmaceutical Excipient PEG400 on the Pharmacokinetics of Baicalin in Cells Based on MRP2, MRP3, and BCRP Efflux Transporters

Pharmaceutical excipient PEG400 is a common component of traditional Chinese medicine compound preparations. Studies have demonstrated that pharmaceutical excipients can directly or indirectly influence the disposition process of active drugs in vivo, thereby affecting the bioavailability of drugs. In order to reveal the pharmacokinetic effect of PEG400 on baicalin in hepatocytes and its mechanism, the present study first started with the effect of PEG400 on the metabolic disposition of baicalin at the hepatocyte level, and then the effect of PEG400 on the protein expression of baicalin-related transporters (BCRP, MRP2, and MRP3) was investigated by using western blot; the effect of MDCKII-BCRP, MDCKII-BCRP, MRP2, and MRP3 was investigated by using MDCKII-BCRP, MDCKII-MRP2, and MDCKII-MRP3 cell monolayer models, and membrane vesicles overexpressing specific transporter proteins (BCRP, MRP2, and MRP3), combined with the exocytosis of transporter-specific inhibitors, were used to study the effects of PEG400 on the transporters in order to explore the possible mechanisms of its action. The results demonstrated that PEG400 significantly influenced the concentration of baicalin in hepatocytes, and the AUC0-t of baicalin increased from 75.96 ± 2.57 μg·h/mL to 106.94 ± 2.22 μg·h/mL, 111.97 ± 3.98 μg·h/mL, and 130.42 ± 5.26 μg·h/mL (p ˂ 0.05). Furthermore, the efflux rate of baicalin was significantly reduced in the vesicular transport assay and the MDCKII cell model transport assay, which indicated that PEG400 had a significant inhibitory effect on the corresponding transporters. In conclusion, PEG400 can improve the bioavailability of baicalin to some extent by affecting the efflux transporters and thus the metabolic disposition of baicalin in the liver.

Influence of Human Bone Marrow Mesenchymal Stem Cells Secretome from Acute Myeloid Leukemia Patients on the Proliferation and Death of K562 and K562-Lucena Leukemia Cell Lineages

Leukemias are among the most prevalent types of cancer worldwide. Bone marrow mesenchymal stem cells (MSCs) participate in the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases such as leukemias, to a yet unknown extent. Here we described the effect of secretome of bone marrow MSCs obtained from healthy donors and from patients with acute myeloid leukemia (AML) on leukemic cell lineages, sensitive (K562) or resistant (K562-Lucena) to chemotherapy drugs. Cell proliferation, viability and death were evaluated, together with cell cycle, cytokine production and gene expression of ABC transporters and cyclins. The secretome of healthy MSCs decreased proliferation and viability of both K562 and K562-Lucena cells; moreover, an increase in apoptosis and necrosis rates was observed, together with the activation of caspase 3/7, cell cycle arrest in G0/G1 phase and changes in expression of several ABC proteins and cyclins D1 and D2. These effects were not observed using the secretome of MSCs derived from AML patients. In conclusion, the secretome of healthy MSCs have the capacity to inhibit the development of leukemia cells, at least in the studied conditions. However, MSCs from AML patients seem to have lost this capacity, and could therefore contribute to the development of leukemia.

The ABCB1 and ABCG2 efflux transporters limit brain disposition of the SYK inhibitors entospletinib and lanraplenib

The highly selective Spleen Tyrosine Kinase (SYK) inhibitors entospletinib and lanraplenib disrupt kinase activity and inhibit immune cell functions. They are developed for treatment of B-cell malignancies and autoimmunity diseases. The impact of P-gp/ABCB1 and BCRP/ABCG2 efflux transporters, OATP1a/1b uptake transporters and CYP3A drug-metabolizing enzymes on the oral pharmacokinetics of these drugs was assessed using mouse models. Entospletinib and lanraplenib were orally administered simultaneously at moderate dosages (10 mg/kg each) to female mice to assess the possibility of examining two structurally and mechanistically similar drugs at the same time, while reducing the number of experimental animals and sample-processing workload. The plasma pharmacokinetics of both drugs were not substantially restricted by Abcb1 or Abcg2. The brain-to-plasma ratios of entospletinib in Abcb1a/b-/-, Abcg2-/- and Abcb1a/b;Abcg2-/- mice were 1.7-, 1.8- and 2.9-fold higher, respectively, compared to those in wild-type mice. For lanraplenib these brain-to-plasma ratios were 3.0-, 1.3- and 10.4-fold higher, respectively. This transporter-mediated restriction of brain penetration for both drugs could be almost fully inhibited by coadministration of the dual ABCB1/ABCG2 inhibitor elacridar, without signs of acute toxicity. Oatp1a/b and human CYP3A4 did not seem to affect the pharmacokinetics of entospletinib and lanraplenib, but mouse Cyp3a may limit lanraplenib plasma exposure. Unexpectedly, entospletinib and lanraplenib increased each other's plasma exposure by 2.6- to 2.9-fold, indicating a significant drug-drug interaction. This interaction was, however, unlikely to be mediated through any of the studied transporters or CYP3A. The obtained insights may perhaps help to further improve the safety and efficacy of entospletinib and lanraplenib.

Genetics of Gallstone Disease and Their Clinical Significance: A Narrative Review

Gallstone (GS) disease is common and arises from a combination of genetic and environmental factors. Although genetic abnormalities specifically leading to cholesterol GSs are rare, there are clinically significant gene variants associated with cholesterol GSs. In contrast, most bilirubin GSs can be attributed to genetic defects. The pathogenesis of cholesterol and bilirubin GSs differs greatly. Cholesterol GSs are notably influenced by genetic variants within the ABC protein superfamily, including ABCG8, ABCG5, ABCB4, and ABCB11, as well as genes from the apolipoprotein family such as ApoB100 and ApoE (especially the E3/E3 and E3/E4 variants), and members of the MUC family. Conversely, bilirubin GSs are associated with genetic variants in highly expressed hepatic genes, notably UGT1A1, ABCC2 (MRP2), ABCC3 (MRP3), CFTR, and MUC, alongside genetic defects linked to hemolytic anemias and conditions impacting erythropoiesis. While genetic cases constitute a small portion of GS disease, recognizing genetic predisposition is essential for proper diagnosis, treatment, and genetic counseling.

Impact of liver diseases and pharmacological interactions on the transportome involved in hepatic drug disposition

The liver plays a pivotal role in drug disposition owing to the expression of transporters accounting for the uptake at the sinusoidal membrane and the efflux across the basolateral and canalicular membranes of hepatocytes of many different compounds. Moreover, intracellular mechanisms of phases I and II biotransformation generate, in general, inactive compounds that are more polar and easier to eliminate into bile or refluxed back toward the blood for their elimination by the kidneys, which becomes crucial when the biliary route is hampered. The set of transporters expressed at a given time, i.e., the so-called transportome, is encoded by genes belonging to two gene superfamilies named Solute Carriers (SLC) and ATP-Binding Cassette (ABC), which account mainly, but not exclusively, for the uptake and efflux of endogenous substances and xenobiotics, which include many different drugs. Besides the existence of genetic variants, which determines a marked interindividual heterogeneity regarding liver drug disposition among patients, prevalent diseases, such as cirrhosis, non-alcoholic steatohepatitis, primary sclerosing cholangitis, primary biliary cirrhosis, viral hepatitis, hepatocellular carcinoma, cholangiocarcinoma, and several cholestatic liver diseases, can alter the transportome and hence affect the pharmacokinetics of drugs used to treat these patients. Moreover, hepatic drug transporters are involved in many drug-drug interactions (DDI) that challenge the safety of using a combination of agents handled by these proteins. Updated information on these questions has been organized in this article by superfamilies and families of members of the transportome involved in hepatic drug disposition.

Foretinib, a c-MET receptor tyrosine kinase inhibitor, tackles multidrug resistance in cancer cells by inhibiting ABCB1 and ABCG2 transporters

BACKGROUND

ABC transporter-mediated multidrug resistance (MDR) remains a major obstacle for cancer pharmacological treatment. Some tyrosine kinase inhibitors (TKIs) have been shown to reverse MDR. The present study was designed to evaluate for the first time whether foretinib, a multitargeted TKI, can circumvent ABCB1 and ABCG2-mediated MDR in treatment-resistant cancer models.

METHODS

Accumulation of fluorescent substrates of ABCB1 and ABCG2 in ABCB1-overexpressing MES-SA/DX5 and ABCG2-overexpressing MCF-7/MX and their parenteral cells was evaluated by flow cytometry. The growth inhibitory activity of single and combination therapy of foretinib and chemotherapeutic drugs on MDR cells was examined by MTT assay. Analysis of combined interaction effects was performed using CalcuSyn software.

RESULTS

It was firstly proved that foretinib increased the intracellular accumulation of rhodamine 123 and mitoxantrone in MES-SA/DX5 and MCF-7/MX cancer cells, with accumulation ratios of 12 and 2.2 at 25 μM concentration, respectively. However, it did not affect the accumulation of fluorescent substrates in the parental cells. Moreover, foretinib synergistically improved the cytotoxic effects of doxorubicin and mitoxantrone. The means of combination index (CI) values at fraction affected (Fa) values of 0.5, 0.75, and 0.9 were 0.64 ± 0.08 and 0.47 ± 0.09, in MES-SA/DX5 and MCF-7/MX cancer cells, respectively. In silico analysis also suggested that the drug-binding domain of ABCB1 and ABCG2 transporters could be considered as potential target for foretinib.

CONCLUSION

Overall, our results suggest that foretinib can target MDR-linked ABCB1 and ABCG2 transporters in clinical cancer therapy.

The emerging roles of sphingosine 1-phosphate and SphK1 in cancer resistance: a promising therapeutic target

Cancer chemoresistance is a problematic dilemma that significantly restrains numerous cancer management protocols. It can promote cancer recurrence, spreading of cancer, and finally, mortality. Accordingly, enhancing the responsiveness of cancer cells towards chemotherapies could be a vital approach to overcoming cancer chemoresistance. Tumour cells express a high level of sphingosine kinase-1 (SphK1), which acts as a protooncogenic factor and is responsible for the synthesis of sphingosine-1 phosphate (S1P). S1P is released through a Human ATP-binding cassette (ABC) transporter to interact with other phosphosphingolipids components in the interstitial fluid in the tumor microenvironment (TME), provoking communication, progression, invasion, and tumor metastasis. Also, S1P is associated with several impacts, including anti-apoptotic behavior, metastasis, mesenchymal transition (EMT), angiogenesis, and chemotherapy resistance. Recent reports addressed high levels of S1P in several carcinomas, including ovarian, prostate, colorectal, breast, and HCC. Therefore, targeting the S1P/SphK signaling pathway is an emerging therapeutic approach to efficiently attenuate chemoresistance. In this review, we comprehensively discussed S1P functions, metabolism, transport, and signaling. Also, through a bioinformatic framework, we pointed out the alterations of SphK1 gene expression within different cancers with their impact on patient survival, and we demonstrated the protein-protein network of SphK1, elaborating its sparse roles. Furthermore, we made emphasis on different machineries of cancer resistance and the tight link with S1P. We evaluated all publicly available SphK1 inhibitors and their inhibition activity using molecular docking and how SphK1 inhibitors reduce the production of S1P and might reduce chemoresistance, an approach that might be vital in the course of cancer treatment and prognosis.

Transcriptomic and metabolomic analysis of the mechanisms underlying stress responses of the freshwater snail, Pomacea canaliculata, exposed to different levels of arsenic

Arsenic (As) pollution poses an important problem, but limited information is available about the physiological effects of As on freshwater invertebrates. Here, we investigated the physiological effects of chronic As exposure on Pomacea canaliculata, a freshwater invertebrate. High level of As (Ⅲ, 5 mg/L) inhibited the growth of P. canaliculata, whereas low level of As (Ⅲ, 2 mg/L) promoted growth. Pathological changes in shell and cellular ultrastructure due to As accumulation likely explain the growth inhibition at high As level. Low level of As simulated the expression of genes related to DNA replication and chitosan biosynthesis, potentially accounting for the growth promotion observed. High level of As enrichment pathways primarily involved cytochrome P450, glutathione, and arachidonic acid-mediated metabolism of xenobiotics. ATP-binding cassette (ABC) transporters, specifically the ABCB and ABCC subfamilies, were involved in As transport. Differential metabolites were mainly associated with the metabolism and biosynthesis of amino acids. These findings elucidate the dose-dependent effects of As stress on P. canaliculata growth, with low levels promoting and high levels inhibiting. Additionally, our findings also provide insights into As metabolism and transport in P. canaliculata.

Emerging roles of ncRNAs regulating ABCC1 on chemotherapy resistance of cancer - a review

In the process of chemotherapy, drug resistance of cancer cells is a common and difficult problem of chemotherapy failure, and it is also the main cause of cancer recurrence and metastasis. Non-coding RNAs (ncRNAs) refer to the RNA that does not encode proteins, including microRNA (miRNA), long non-coding RNA (lncRNA) and circularRNA (circRNA), etc. NcRNAs are involved in a series of important life processes and further regulate the expression of ABCC1 by directly or indirectly up-regulating or down-regulating the expression of targeted mRNAs, making cancer cells more susceptible to drug resistance. A growing number of studies have shown that ncRNAs have effects on cancer cell proliferation, invasion, metastasis, and drug sensitivity, by regulating the expression of ABCC1. In this review, we will discuss the emerging roles of ncRNAs regulating ABCC1 in chemotherapy resistance and mechanisms to reverse drug resistance as well as provide potential targets for future cancer treatment.

Emerging mechanisms of the unfolded protein response in therapeutic resistance: from chemotherapy to Immunotherapy

The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR). As an adaptive cellular response to hostile microenvironments, such as hypoxia, nutrient deprivation, oxidative stress, and chemotherapeutic drugs, the UPR is activated in diverse cancer types and functions as a dynamic tumour promoter in cancer development; this role of the UPR indicates that regulation of the UPR can be utilized as a target for tumour treatment. T-cell exhaustion mainly refers to effector T cells losing their effector functions and expressing inhibitory receptors, leading to tumour immune evasion and the loss of tumour control. Emerging evidence suggests that the UPR plays a crucial role in T-cell exhaustion, immune evasion, and resistance to immunotherapy. In this review, we summarize the molecular basis of UPR activation, the effect of the UPR on immune evasion, the emerging mechanisms of the UPR in chemotherapy and immunotherapy resistance, and agents that target the UPR for tumour therapeutics. An understanding of the role of the UPR in immune evasion and therapeutic resistance will be helpful to identify new therapeutic modalities for cancer treatment. Video Abstract.

Structural bioinformatics studies of six human ABC transporters and their AlphaFold2-predicted water-soluble QTY variants

Human ATP-binding cassette (ABC) transporters are one of the largest families of membrane proteins and perform diverse functions. Many of them are associated with multidrug resistance that often results in cancer treatment with poor outcomes. Here, we present the structural bioinformatics study of six human ABC membrane transporters with experimentally determined cryo-electron microscopy (CryoEM) structures including ABCB7, ABCC8, ABCD1, ABCD4, ABCG1, ABCG5, and their AlphaFold2-predicted water-soluble QTY variants. In the native structures, there are hydrophobic amino acids such as leucine (L), isoleucine (I), valine (V), and phenylalanine (F) in the transmembrane alpha helices. These hydrophobic amino acids are systematically replaced by hydrophilic amino acids glutamine (Q), threonine (T), and tyrosine (Y). Therefore, these QTY variants become water soluble. We also present the superposed structures of native ABC transporters and their water-soluble QTY variants. The superposed structures show remarkable similarity with root mean square deviations between 1.064 and 3.413 Å despite significant (41.90-54.33%) changes to the protein sequence of the transmembrane domains. We also show the differences in hydrophobicity patches between the native ABC transporters and their QTY variants. We explain the rationale behind why the QTY membrane protein variants become water soluble. Our structural bioinformatics studies provide insight into the differences between the hydrophobic helices and hydrophilic helices and will likely further stimulate designs of water-soluble multispan transmembrane proteins and other aggregated proteins. The water-soluble ABC transporters may be useful as soluble antigens to generate therapeutic monoclonal antibodies for combating multidrug resistance in clinics.

Up-regulation of ABCG1 is associated with methotrexate resistance in acute lymphoblastic leukemia cells

Acute lymphoblastic leukemia (ALL) is a prevalent hematologic malignancy in children, and methotrexate (MTX) is a widely employed curative treatment. Despite its common use, clinical resistance to MTX is frequently encountered. In this study, an MTX-resistant cell line (Reh-MTXR) was established through a stepwise selection process from the ALL cell line Reh. Comparative analysis revealed that Reh-MTXR cells exhibited resistance to MTX in contrast to the parental Reh cells. RNA-seq analysis identified an upregulation of ATP-binding cassette transporter G1 (ABCG1) in Reh-MTXR cells. Knockdown of ABCG1 in Reh-MTXR cells reversed the MTX-resistant phenotype, while overexpression of ABCG1 in Reh cells conferred resistance to MTX. Mechanistically, the heightened expression of ABCG1 accelerated MTX efflux, leading to a reduced accumulation of MTX polyglutamated metabolites. Notably, the ABCG1 inhibitor benzamil effectively sensitized Reh-MTXR cells to MTX treatment. Moreover, the observed upregulation of ABCG1 in Reh-MTXR cells was not induced by alterations in DNA methylation or histone acetylation. This study provides insight into the mechanistic basis of MTX resistance in ALL and also suggests a potential therapeutic approach for MTX-resistant ALL in the future.

Multimodal Nanoplatform with ROS Amplification to Overcome Multidrug Resistance in Prostate Cancer via Targeting P-Glycoprotein and Ferroptosis

Chemotherapy remains the most essential treatment for prostate cancer, but multidrug resistance (MDR) contributes to chemotherapy failure and tumor-related deaths. The overexpression of P-glycoprotein (P-gp) is one of the main mechanisms behind MDR. Here, this work reports a multimodal nanoplatform with a reactive oxygen species (ROS) cascade for gas therapy/ferroptosis/chemotherapy in reversing MDR. The nanoplatform disassembles when responding to intracellular ROS and exerts three main functions: First, nitric oxide (NO) targeted delivery can reverse MDR by downregulating P-gp expression and inhibiting mitochondrial function. Second, ferrocene-induced ferroptosis breaks the redox balance in the tumor intracellular microenvironment and synergistically acts against the tumor. Third, the release of paclitaxel (PTX) is precisely controlled in situ in the tumor for chemotherapy that avoids damage to normal tissues. Excitingly, this multimodal nanoplatform is a promising weapon for reversing MDR and may provide a pioneering paradigm for synergetic cancer therapy.

Mechanisms of tyrosine kinase inhibitor resistance in renal cell carcinoma

Renal cell carcinoma (RCC), the most prevalent type of kidney cancer, is a significant cause of cancer morbidity and mortality worldwide. Antiangiogenic tyrosine kinase inhibitors (TKIs), in combination with immune checkpoint inhibitors (ICIs), are among the first-line treatment options for patients with advanced RCC. These therapies target the vascular endothelial growth factor receptor (VEGFR) tyrosine kinase pathway and other kinases crucial to cancer proliferation, survival, and metastasis. TKIs have yielded substantial improvements in progression-free survival (PFS) and overall survival (OS) for patients with advanced RCC. However, nearly all patients eventually progress on these drugs as resistance develops. This review provides an overview of TKI resistance in RCC and explores different mechanisms of resistance, including upregulation of alternative proangiogenic pathways, epithelial-mesenchymal transition (EMT), decreased intracellular drug concentrations due to efflux pumps and lysosomal sequestration, alterations in the tumor microenvironment including bone marrow-derived cells (BMDCs) and tumor-associated fibroblasts (TAFs), and genetic factors such as single nucleotide polymorphisms (SNPs). A comprehensive understanding of these mechanisms opens the door to the development of innovative therapeutic approaches that can effectively overcome TKI resistance, thereby improving outcomes for patients with advanced RCC.

Exploration of biomarkers for systemic lupus erythematosus by machine-learning analysis

BACKGROUND

In recent years, research on the pathogenesis of systemic lupus erythematosus (SLE) has made great progress. However, the prognosis of the disease remains poor, and high sensitivity and accurate biomarkers are particularly important for the early diagnosis of SLE.

METHODS

SLE patient information was acquired from three Gene Expression Omnibus (GEO) databases and used for differential gene expression analysis, such as weighted gene coexpression network (WGCNA) and functional enrichment analysis. Subsequently, three algorithms, random forest (RF), support vector machine-recursive feature elimination (SVM-REF) and least absolute shrinkage and selection operation (LASSO), were used to analyze the above key genes. Furthermore, the expression levels of the final core genes in peripheral blood from SLE patients were confirmed by real-time quantitative polymerase chain reaction (RT-qPCR) assay.

RESULTS

Five key genes (ABCB1, CD247, DSC1, KIR2DL3 and MX2) were found in this study. Moreover, these key genes had good reliability and validity, which were further confirmed by clinical samples from SLE patients. The receiver operating characteristic curves (ROC) of the five genes also revealed that they had critical roles in the pathogenesis of SLE.

CONCLUSION

In summary, five key genes were obtained and validated through machine-learning analysis, offering a new perspective for the molecular mechanism and potential therapeutic targets for SLE.

Matrix stiffness triggers chemoresistance through elevated autophagy in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a signature of extremely high matrix stiffness caused by a special desmoplastic reaction, which dynamically stiffens along with the pathological process. The poor prognosis and low five-year survival rate of PDAC are partly owing to chemoresistance triggered by substrate stiffness. Understanding the potential mechanisms of matrix stiffness causing PDAC chemoresistance is of great significance. In this study, methacrylated gelatin hydrogel was used as platform for PANC-1 and MIA-PaCa2 cell culture. The results indicated that compared to soft substrate, stiff substrate distinctively reduced the gemcitabine sensitivity of pancreatic cancer. Intriguingly, transmission electron microscopy, immunofluorescence staining, western blot and qRT-PCR assay showcased that the number of autophagosomes and the expression of LC3 were elevated. The observations indicate that matrix stiffness may regulate the autophagy level, which plays a vital role during chemoresistance. In brief, soft substrate exhibited low autophagy level, while the counterpart displayed elevated autophagy level. In order to elucidate the underlying interaction between matrix stiffness-mediated cell autophagy and chemoresistance, rescue experiments with rapamycin and chloroquine were conducted. We found that inhibiting cell autophagy dramatically increased the sensitivity of pancreatic cancer cells to gemcitabine in the stiff group, while promoting autophagy-driven chemoresistance in the soft group, demonstrating that matrix stiffness modulated chemoresistance via autophagy. Furthermore, RNA-seq results showed that miR-1972 may regulate autophagy level in response to matrix stiffness. Overall, our research shed light on the synergistic therapy of PDAC combined with gemcitabine and chloroquine, which is conducive to promoting a therapeutic effect.

Hedgehog signaling guides migration of primordial germ cells to the Drosophila somatic gonad

In addition to inducing nonautonomous specification of cell fate in both Drosophila and vertebrates, the Hedgehog pathway guides cell migration in a variety of different tissues. Although its role in axon guidance in the vertebrate nervous system is widely recognized, its role in guiding the migratory path of primordial germ cells (PGCs) from the outside surface of the Drosophila embryo through the midgut and mesoderm to the SGPs (somatic gonadal precursors) has been controversial. Here we present new experiments demonstrating (1) that Hh produced by mesodermal cells guides PGC migration, (2) that HMG CoenzymeA reductase (Hmgcr) potentiates guidance signals emanating from the SGPs, functioning upstream of hh and of 2 Hh pathway genes important for Hh-containing cytonemes, and (3) that factors required in Hh receiving cells in other contexts function in PGCs to help direct migration toward the SGPs. We also compare the data reported by 4 different laboratories that have studied the role of the Hh pathway in guiding PGC migration.

Pharmacokinetics of the KRASG12C inhibitor adagrasib is limited by CYP3A and ABCB1, and influenced by binding to mouse plasma carboxylesterase 1c

Adagrasib (Krazati™) is the second FDA-approved specific KRASG12C inhibitor for non-small cell lung cancer (NSCLC) patients harboring this mutation. The impact of the drug efflux transporters ABCB1 and ABCG2, and the drug-metabolizing enzymes CYP3A and carboxylesterase 1 (CES1) on the pharmacokinetics of oral adagrasib were studied using genetically modified mouse models. Adagrasib was potently transported by human ABCB1 and modestly by mouse Abcg2 in vitro. In Abcb1a/b-/- and Abcb1a/b;Abcg2-/- mice, the brain-to-plasma ratios were enhanced by 33- and 55-fold, respectively, compared to wild-type mice, whereas ratios in Abcg2-/- mice remained unchanged. The influence of ABC transporters was completely reversed by coadministration of the dual ABCB1/ABCG2 inhibitor elacridar, increasing the brain penetration in wild-type mice by 41-fold while no signs of acute CNS toxicity were observed. Tumor ABCB1 overexpression may thus confer adagrasib resistance. Whereas the ABC transporters did not affect adagrasib plasma exposure, CYP3A and Ces1 strongly impacted its apparent oral availability. The plasma AUC0-8 h was significantly enhanced by 2.3-fold in Cyp3a-/- compared to wild-type mice, and subsequently 4.3-fold reduced in transgenic CYP3A4 mice, indicating substantial CYP3A-mediated metabolism. Adagrasib plasma exposure was strongly reduced in Ces1-/- compared to wild-type mice, but tissue exposure was slightly increased, suggesting that adagrasib binds to plasma Ces1c in mice and is perhaps metabolized by Ces1. This binding could complicate interpretation of mouse studies, especially since humans lack circulating CES1 enzyme(s). Our results may be useful to further optimize the clinical safety and efficacy of adagrasib, and give more insight into potential drug-drug interactions risks.

Role of SIRT1 in Chemoresistant Leukemia

Leukemias of the AML, CML, and CLL types are the most common blood cancers worldwide, making them a major global public health problem. Furthermore, less than 24% of patients treated with conventional chemotherapy (low-risk patients) and 10-15% of patients ineligible for conventional chemotherapy (high-risk patients) survive five years. The low levels of survival are mainly due to toxicity and resistance to chemotherapy or other medication, the latter leading to relapse of the disease, which is the main obstacle to the treatment of leukemia. Drug resistance may include different molecular mechanisms, among which epigenetic regulators are involved. Silent information regulator 2 homolog 1 (SIRT1) is an epigenetic factor belonging to the sirtuin (SIRT) family known to regulate aspects of chromatin biology, genome stability, and metabolism, both in homeostasis processes and in different diseases, including cancer. The regulatory functions of SIRT1 in different biological processes and molecular pathways are dependent on the type and stage of the neoplasia; thus, it may act as both an oncogenic and tumor suppressor factor and may also participate in drug resistance. In this review, we explore the role of SIRT1 in drug-resistant leukemia and its potential as a therapeutic target.

Changes in Expression and Function of Placental and Intestinal P-gp and BCRP Transporters during Pregnancy

ABC transporters are ubiquitous in the human body and are responsible for the efflux of drugs. They are present in the placenta, intestine, liver and kidney, which are the major organs that can affect the pharmacokinetic and pharmacologic properties of drugs. P-gp and BCRP transporters are the best-characterized transporters in the ABC superfamily, and they have a pivotal role in the barrier tissues due to their efflux mechanism. Moreover, during pregnancy, drug efflux is even more important because of the developing fetus. Recent studies have shown that placental and intestinal ABC transporters have great importance in drug absorption and distribution. Placental and intestinal P-gp and BCRP show gestational-age-dependent expression changes, which determine the drug concentration both in the mother and the fetus during pregnancy. They may have an impact on the efficacy of antibiotic, antiviral, antihistamine, antiemetic and oral antidiabetic therapies. In this review, we would like to provide an overview of the pharmacokinetically relevant expression alterations of placental and intestinal ABC transporters during pregnancy.

A Genome-Wide Analysis of a Sudden Cardiac Death Cohort: Identifying Novel Target Variants in the Era of Molecular Autopsy

Sudden cardiac death (SCD) is an unexpected natural death due to cardiac causes, usually happening within one hour of symptom manifestation or in individuals in good health up to 24 h before the event. Genomic screening has been increasingly applied as a useful approach to detecting the genetic variants that potentially contribute to SCD and helping the evaluation of SCD cases in the post-mortem setting. Our aim was to identify the genetic markers associated with SCD, which might enable its target screening and prevention. In this scope, a case-control analysis through the post-mortem genome-wide screening of 30 autopsy cases was performed. We identified a high number of novel genetic variants associated with SCD, of which 25 polymorphisms were consistent with a previous link to cardiovascular diseases. We ascertained that many genes have been already linked to cardiovascular system functioning and diseases and that the metabolisms most implicated in SCD are the lipid, cholesterol, arachidonic acid, and drug metabolisms, suggesting their roles as potential risk factors. Overall, the genetic variants pinpointed herein might be useful markers of SCD, but the novelty of these results requires further investigations.

Hepatic transcriptome analysis provides new insights into ghrelin regulation of the liver in Nile tilapia (Oreochromis niloticus)

Ghrelin is a growth-promoting hormone produced by the gastrointestinal tract that plays a crucial role through the ghrelin-growth hormone secretagogue receptor (GHS-R) and growth hormone/insulin-like growth factor-1 (GH/IGF-1) axes. To explore the effect of ghrelin on the transcriptomic profile of tilapia liver, the hepatic transcriptome of tilapia was sequenced for two groups, including saline-injected control (CL) and ghrelin-injected (GL; 2 μg/g body weight) tilapia. The transcriptome of livers from the two groups was sequenced using an Illumina HiSeqTM 2000 platform and yielded approximately 310.53 million raw reads. Subsequently, approximately 308.51 million clean reads were obtained from the total raw reads using in-house Perl scripts. Approximately 92.36% clean reads were mapped to the Nile tilapia genome using RSEM. Using the DESeq package, 250 differentially expressed genes (DEGs) were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed enrichment of two pathways related to RNA transcription (ribosome biogenesis in eukaryotes pathway and RNA transport pathway), with a total of 14 functional DEGs. ATP-binding and muscle contraction terms were identified as enriched using Gene Ontology (GO), yielding a total of 28 DEGs. Finally, real-time quantitative PCR (RT-qPCR) was used to confirm the accuracy of the transcriptomic results. The results of RT-qPCR were highly consistent with the RNA-seq, indicating that results of RNA-seq were valid. The differences in gene expression between the groups indicated that ghrelin-injection altered energy metabolism and RNA transcription in the tilapia liver, which provides new information to help promote the growth of tilapia.

An ABCG-type transporter intensifies ametryn catabolism by Phase III reaction mechanism in rice

Pesticide residues in food crops are one of the seriously environmental contaminants that risk food safety and human health. Understanding the mechanism for pesticide catabolism is critical to develop effective biotechniques for rapid eliminating the residues in food crops. In this study we characterized a novel ABC transporter family gene ABCG52 (PDR18) in regulating rice response to pesticide ametryn (AME) widely used in the farmland. Efficient biodegradation of AME was evaluated by measuring its biotoxicity, accumulation, and metabolites in rice plants. OsPDR18 was localized to the plasma membrane and strongly induced under AME exposure. Transgenic rice overexpressing OsPDR18 (OE) conferred rice resistance and detoxification to AME by increasing chlorophyll contents, improving growth phenotypes, and reducing AME accumulation in plants. The AME concentrations in OE plants were only 71.8-78.1% (shoots) and 75.0-83.3% (roots) of the wild type. Mutation of OsPDR18 by CRISPR/Cas9 protocol led to the compromised growth and enhanced AME accumulation in rice. Five AME metabolites for Phase I and 13 conjugates for Phase II reactions in rice were characterized by HPLC/Q-TOF-HRMS/MS. Relative content analysis revealed that the AME metabolic products in OE plants were significantly reduced compared with wild-type. Importantly, the OE plants accumulated less AME metabolites and conjugates in rice grains, suggesting that OsPDR18 expression may actively facilitate the transport of AME for catabolism. These data unveil a AME catabolic mechanism by which OsPDR18 contributes to the AME detoxification and degradation in rice crops.

Simultaneous quantification of pirarubicin, doxorubicin, cyclophosphamide, and vincristine in human plasma of patients with non-Hodgkin's lymphoma by LC-MS/MS method

Pirarubicin (THP), doxorubicin (DOX), cyclophosphamide (CTX), and vincristine (VCR) are widely used in the treatment of patients with non-Hodgkin's Lymphoma. Herein, a precise and sensitive method was developed for the determination of THP, DOX, CTX and VCR in human plasma by high-performance liquid-chromatography-tandem mass spectrometry (LC-MS/MS). Liquid-liquid extraction was applied to extract THP, DOX, CTX, VCR, and the internal standard (IS, Pioglitazone) in plasma. Agilent Eclipse XDB-C18 (3.0 mm × 100 mm) was utilized and chromatographic separation was obtained in eight minutes. Mobile phases were composed of methanol and buffer (10 mM ammonium formate containing 0.1% formic acid). The method was linear within the concentration range of 1-500 ng/mL for THP, 2-1000 ng/mL for DOX, 2.5-1250 ng/mL for CTX, and 3-1500 ng/mL for VCR. The intra- and inter-day precisions of QC samples were found to be below 9.31 and 13.66%, and accuracy ranged from -0.2 to 9.07%, respectively. THP, DOX, CTX, VCR and the internal standard were stable in several conditions. Finally, this method was successfully utilized to simultaneously determine THP, DOX, CTX and VCR in human plasma of 15 patients with non-Hodgkin's Lymphoma after intravenous administration. Finally, the method was successfully employed in the clinical determination of THP, DOX, CTX, and VCR in patients with non-Hodgkin lymphoma after administration of RCHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) regimens.

Preliminary Exploration of Metabolic Mechanisms in Copper-Exposed Sepia esculenta Based on Transcriptome Analysis

As a common and high-concentration heavy metal in the ocean, Cu can induce metal toxicity and significantly affect the metabolic function of marine organisms. Sepia esculenta is an important economic cephalopod found along the east coast of China, the growth, movement, and reproduction of which are all affected by heavy metals. Hitherto, the specific metabolic mechanism of heavy-metal exposure in S. esculenta is still unclear. In this study, we identified 1131 DEGs through transcriptome analysis of larval S. esculenta within 24 h of Cu exposure. GO and KEGG functional enrichment analysis results indicated that Cu exposure may affect purine metabolism, protein digestion and absorption, cholesterol metabolism, and other metabolic processes in S. esculenta larvae. It is worth noting that in this study we explore metabolic mechanism of Cu-exposed S. esculenta larvae through the comprehensive analysis of protein–protein interaction network and KEGG enrichment analysis for the first time and find 20 identified key and hub genes such as CYP7A1, CYP3A11, and ABCA1. Based on their expression, we preliminarily speculate that Cu exposure may inhibit multiple metabolic processes and induce metabolic disorders. Our results lay a foundation for further understanding the metabolic mechanism of S. esculenta against heavy metals and provide theoretical help for S. esculenta artificial breeding.

Differential Effects of ABCG5/G8 Gene Region Variants on Lipid Profile, Blood Pressure Status, and Gallstone Disease History in Taiwan

ABCG5 and ABCG8 are two key adenosine triphosphate-binding cassette (ABC) proteins that regulate whole-body sterol trafficking. This study aimed to elucidate the association between ABCG5/G8 gene region variants and lipid profile, cardiometabolic traits, and gallstone disease history in Taiwan. A total of 1494 Taiwan Biobank participants with whole-genome sequencing data and 117,679 participants with Axiom Genome-Wide CHB Array data were enrolled for analysis. Using genotype-phenotype and stepwise linear regression analyses, we found independent associations of four Asian-specific ABCG5 variants, rs119480069, rs199984328, rs560839317, and rs748096191, with total, low-density lipoprotein (LDL), and non-high-density lipoprotein (HDL) cholesterol levels (all p ≤ 0.0002). Four other variants, which were in nearly complete linkage disequilibrium, exhibited genome-wide significant associations with gallstone disease history, and the ABCG8 rs11887534 variant showed a trend of superiority for gallstone disease history in a nested logistic regression model (p = 0.074). Through regional association analysis of various other cardiometabolic traits, two variants of the PLEKHH2, approximately 50 kb from the ABCG5/G8 region, exhibited significant associations with blood pressure status (p < 10^-6). In conclusion, differential effects of ABCG5/G8 region variants were noted for lipid profile, blood pressure status, and gallstone disease history in Taiwan. These results indicate the crucial role of individualized assessment of ABCG5/G8 variants for different cardiometabolic phenotypes.

Transcriptomic Profiling of Fusarium pseudograminearum in Response to Carbendazim, Pyraclostrobin, Tebuconazole, and Phenamacril

Fusarium pseudograminearum has been identified as a significant pathogen. It causes Fusarium crown rot (FCR), which occurs in several major wheat-producing areas in China. Chemical control is the primary measure with which to control this disease. In this study, transcriptome sequencing (RNA-Seq) was used to determine the different mechanisms of action of four frequently used fungicides including carbendazim, pyraclostrobin, tebuconazole, and phenamacril on F. pseudograminearum. In brief, 381, 1896, 842, and 814 differentially expressed genes (DEGs) were identified under the carbendazim, pyraclostrobin, tebuconazole, and phenamacril treatments, respectively. After the joint analysis, 67 common DEGs were obtained, and further functional analysis showed that the ABC transported pathway was significantly enriched. Moreover, FPSE_04130 (FER6) and FPSE_11895 (MDR1), two important ABC multidrug transporter genes whose expression levels simultaneously increased, were mined under the different treatments, which unambiguously demonstrated the common effects. In addition, Mfuzz clustering analysis and WGCNA analysis revealed that the core DEGs are involved in several critical pathways in each of the four treatment groups. Taken together, these genes may play a crucial function in the mechanisms of F. pseudograminearum's response to the fungicides stress.

Fluorescence-based methods for studying activity and drug-drug interactions of hepatic solute carrier and ATP binding cassette proteins involved in ADME-Tox

In humans, approximately 70% of drugs are eliminated through the liver. This process is governed by the concerted action of membrane transporters and metabolic enzymes. Transporters mediating hepatocellular uptake of drugs belong to the SLC (Solute carrier) superfamily of transporters. Drug efflux either toward the portal vein or into the bile is mainly mediated by active transporters of the ABC (ATP Binding Cassette) family. Alteration in the function and/or expression of liver transporters due to mutations, disease conditions, or co-administration of drugs or food components can result in altered pharmacokinetics. On the other hand, drugs or food components interacting with liver transporters may also interfere with liver function (e.g., bile acid homeostasis) and may even cause liver toxicity. Accordingly, certain transporters of the liver should be investigated already at an early stage of drug development. Most frequently radioactive probes are applied in these drug-transporter interaction tests. However, fluorescent probes are cost-effective and sensitive alternatives to radioligands, and are gaining wider application in drug-transporter interaction tests. In our review, we summarize our current understanding about hepatocyte ABC and SLC transporters affected by drug interactions. We provide an update of the available fluorescent and fluorogenic/activable probes applicable in in vitro or in vivo testing of these ABC and SLC transporters, including near-infrared transporter probes especially suitable for in vivo imaging. Furthermore, our review gives a comprehensive overview of the available fluorescence-based methods, not directly relying on the transport of the probe, suitable for the investigation of hepatic ABC or SLC-type drug transporters.

Bufalin reverses ABCB1-mediated resistance to docetaxel in breast cancer

Background

Docetaxel (DCT) is widely used in clinical practice, but the drug resistance of breast cancer patients has become an important reason to limit its clinical efficacy. Chan'su is a commonly used traditional Chinese medicine for the treatment of breast cancer. Bufalin (BUF) is a bioactive polyhydroxy steroid extracted from chan'su and has strong antitumor activity, but there are few studies on reversing drug resistance in breast cancer. The aim of this study is to determine whether BUF can reverse the drug resistance to DCT and restore efficacy in breast cancer.

Methodology

The reversal index of BUF was detected by Cell Counting Kit-8 (CCK-8) assays. The effects of BUF on enhancing the apoptosis of DCT were detected by flow cytometry and Western Blot (WB), and the main differential expression levels of sensitive and resistant strains were detected by high-throughput sequencing. Rhodamine 123 assay, WB and ATP Binding Cassette Subfamily B Member 1 (ABCB1) ATPase activity experiments were used to detect the effect of BUF on ABCB1. The nude mouse orthotopic model was constructed to investigate the reversal effect of BUF on DCT resistance in vivo.

Results

With BUF intervention, the sensitivity of drug-resistant cell lines to DCT was increased. BUF can inhibit the expression of ABCB1 protein, increase the drug accumulation of DCT in drug-resistant strains, and reduce the ATPase activity of ABCB1. Animal experiments show that BUF can inhibit the growth of drug-resistant tumors in an orthotopic model of breast cancer and decrease the expression of ABCB1.

Conclusion

BUF can reverse ABCB1-mediated docetaxel resistance in breast cancer.

ATP-binding cassette efflux transporters and MDR in cancer

Of the many known multidrug resistance (MDR) mechanisms, ATP-binding cassette (ABC) transporters expelling drug molecules out of cells is a major factor limiting the efficacy of present-day anticancer drugs. In this review, we highlights updated information on the structure, function, and regulatory mechanisms of major MDR-related ABC transporters, such as P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP), and the effect of modulators on their functions. We also provide focused information on different modulators of ABC transporters that could be utilized against the emerging MDR crisis in cancer treatment. Finally, we discuss the importance of ABC transporters as therapeutic targets in light of future strategic planning for translating ABC transporter inhibitors into clinical practice.

Dual Sensitization Anti-Resistant Nanoparticles for Treating Refractory Breast Cancers via Apoptosis-Inducing

Purpose

Current chemotherapy fails to offer a desirable efficacy in clinical treatment against breast cancer due to the extensive multi-drug resistance. In this study, we developed dual sensitization anti-resistant nanoparticles to treat refractory breast cancer, aiming to benefit from photodynamic therapy and chemotherapy.

Methods

Hyaluronic acid (HA) derivative and photosensitizer chlorin e6 (Ce6) derivative were synthesized and confirmed by mass spectrometry. These derivatives and the chemotherapy agent paclitaxel were incorporated into nanoparticles by an emulsion-solvent evaporation method. The prepared nanoparticles were characterized by dynamic laser scattering, atomic force microscopy, and high performance liquid chromatography (HPLC). The efficacy and mechanisms of the nanoparticles, both in vitro and in vivo, were investigated by flow cytometry, confocal/fluorescence microscopy, and a high-content screening system.

Results

The prepared dual sensitization anti-resistant nanoparticles were round with a diameter of ~ 100 nm, exhibiting high encapsulation efficiency for the anticancer agent paclitaxel. The nanoparticles demonstrated a robust inhibitory effect against drug-resistant breast cancer cells by enhanced uptake, synergistic effect of photodynamic therapy and chemotherapy, and apoptosis-inducing via multiple pathways. In vivo efficacy, biocompatibility and safety were further confirmed acceptable in tumor-bearing mice.

Conclusion

The prepared dual sensitization anti-resistant nanoparticles were promising to treat refractory breast cancer with a controllable treatment site and minimal side effects.

Artificial Base-Directed In Vivo Assembly of an Albumin-siRNA Complex for Tumor-Targeting Delivery

RNA interference (RNAi) mediated by short interfering RNA (siRNA) is a promising method for cancer treatment, but the clinical application is hampered by several limitations, including metabolic instability, lack of tumor specificity, and poor cellular uptake. To meet these challenges, we have explored the possibility of structure modification of siRNA with artificial bases for property optimization. A series of siRNAs functionalized with different numbers of hydrophobic base F are prepared for screening. The interactions of plasma proteins with F-base-modified siRNA (F-siRNA) are investigated, and it is identified that the interaction with serum albumin is dominant. Experiments revealed that the introduction of F bases conferred modified siRNA with improved tumor-specific accumulation, prolonged circulatory retention time, and better tissue permeability. Mechanistic studies indicated that the F base induces the formulation of a stable siRNA-albumin complex, which transports siRNA to tumor tissues selectively owing to an enhanced permeability and retention (EPR) effect of albumin. The F base also facilitates the binding of siRNA to transport-associated proteins on the cell membrane, enabling its cellular internalization. Together, these data demonstrate that F base modification confers siRNA-enhanced cellular uptake and biostability and specific accumulation in tumor tissue, which provides a new approach for the development of siRNA-based cancer therapeutics.

ABC transporters: human disease and pharmacotherapeutic potential

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are a 48-member superfamily of membrane proteins that actively transport a variety of biological substrates across lipid membranes. Their functional diversity defines an expansive involvement in myriad aspects of human biology. At least 21 ABC transporters underlie rare monogenic disorders, with even more implicated in the predisposition to and symptomology of common and complex diseases. Such broad (patho)physiological relevance places this class of proteins at the intersection of disease causation and therapeutic potential, underlining them as promising targets for drug discovery, as exemplified by the transformative CFTR (ABCC7) modulator therapies for cystic fibrosis. This review will explore the growing relevance of ABC transporters to human disease and their potential as small-molecule drug targets.

Design, Synthesis and Biological Evaluation of Quinazolinamine Derivatives as Breast Cancer Resistance Protein and P-Glycoprotein Inhibitors with Improved Metabolic Stability

A series of twenty-two quinazolinamine derivatives showing potent inhibitory activities on breast cancer resistance protein (BCRP) and p-glycoprotein (P-gp) were synthesized. A cyclopropyl-containing quinazolinamine 22 was identified as a dual BCRP and P-gp inhibitor, while azide-containing quinazolinamine 33 showed BCRP inhibitory activity. These lead compounds were further investigated in a battery of mechanistic experiments. Compound 22 changed the localization of BCRP and P-gp in cells, thus inhibiting the efflux of anticancer drugs by the two ATP-binding cassette (ABC) transporters. In addition, both 22 and 33 significantly stimulated the ATP hydrolysis of the BCRP transporter, indicating that they can be competitive substrates of the BCRP transporter, and thereby increase the accumulation of mitoxantrone in BCRP-overexpressing H460/MX20 cells. Azide derivative 33, exhibited a greater inhibitory effect on BCRP after UV activation and can serve as a valuable probe for investigating the interactions of quinazolinamine derivatives with BCRP. Notably, the dual BCRP and P-gp inhibitors 4-5, 22-24, 27, and BCRP inhibitor 33 showed improved metabolic stability compared to Ko143.

Rapid PTEFb-dependent transcriptional reorganization underpins the glioma adaptive response to radiotherapy

Dynamic regulation of gene expression is fundamental for cellular adaptation to exogenous stressors. PTEFb-mediated pause-release of RNA polymerase II (Pol II) is a conserved regulatory mechanism for synchronous transcriptional induction in response to heat shock, but this pro-survival role has not been examined in the applied context of cancer therapy. Using model systems of pediatric high-grade glioma, we show that rapid genome-wide reorganization of active chromatin facilitates PTEFb-mediated nascent transcriptional induction within hours of exposure to therapeutic ionizing radiation. Concurrent inhibition of PTEFb disrupts this chromatin reorganization and blunts transcriptional induction, abrogating key adaptive programs such as DNA damage repair and cell cycle regulation. This combination demonstrates a potent, synergistic therapeutic potential agnostic of glioma subtype, leading to a marked induction of tumor cell apoptosis and prolongation of xenograft survival. These studies reveal a central role for PTEFb underpinning the early adaptive response to radiotherapy, opening new avenues for combinatorial treatment in these lethal malignancies.

Effects of altitude on the gut microbiome and metabolomics of Sanhe heifers

Introduction

Extreme environments at high altitudes pose a significant physiological challenge to animals. We evaluated the gut microbiome and fecal metabolism in Sanhe heifers from different altitudes.

Methods

Twenty Sanhe heifers (body weight: 334.82 ± 13.22 kg, 15-month-old) selected from two regions of China: the Xiertala Cattle Breeding Farm in Hulunbeier, Inner Mongolia [119°57' E, 47°17' N; approximately 700 m altitude, low altitude (LA)] and Zhizhao Dairy Cow Farm in Lhasa, Tibet [91°06' E, 29°36' N; approximately 3,650 m altitude, high altitude (HA)], were used in this study. Fecal samples were collected and differences in the gut microbiota and metabolomics of Sanhe heifers were determined using 16S rRNA gene sequencing and metabolome analysis.

Results and discussion

The results showed that altitude did not significantly affect the concentrations of fecal volatile fatty acids, including acetate, propionate, butyrate, and total volatile fatty acids (p > 0.05). However, 16S rRNA gene sequencing showed that altitude significantly affected gut microbial composition. Principal coordinate analysis based on Bray-Curtis dissimilarity analysis revealed a significant difference between the two groups (p = 0.001). At the family level, the relative abundances of Peptostreptococcaceae, Christensenellaceae, Erysipelotrichaceae, and Family_XIII were significantly lower (p < 0.05) in LA heifers than in HA heifers. In addition, the relative abundances of Lachnospiraceae, Domibacillus, Bacteroidales_S24-7_group, Bacteroidales_RF16_group, Porphyromonadaceae, and Spirochaetaceae were significantly higher in HA heifers than in LA heifers (p < 0.05). Metabolomic analysis revealed the enrichment of 10 metabolic pathways, including organismal systems, metabolism, environmental information processing, genetic information processing, and disease induction. The genera Romboutsia, Paeniclostridium, and g_unclassified_f_Lachnospiraceae were strongly associated with the 28 differential metabolites. This study is the first to analyze the differences in the gut microbiome and metabolome of Sanhe heifers reared at different altitudes and provides insights into the adaptation mechanism of Sanhe heifers to high-altitude areas.

COVID-19 drugs: potential interaction with ATP-binding cassette transporters P-glycoprotein and breast cancer resistance protein

Background

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has resulted in acute respiratory distress, fatal systemic manifestations (extrapulmonary as well as pulmonary), and premature mortality among many patients. Therapy for COVID-19 has focused on the treatment of symptoms and of acute inflammation (cytokine storm) and the prevention of viral infection. Although the mechanism of COVID-19 is not fully understood, potential clinical targets have been identified for pharmacological, immunological, and vaccinal approaches.

Area covered

Pharmacological approaches including drug repositioning have been a priority for initial COVID-19 therapy due to the time-consuming nature of the vaccine development process. COVID-19 drugs have been shown to manage the antiviral infection cycle (cell entry and replication of proteins and genomic RNA) and anti-inflammation. In this review, we evaluated the interaction of current COVID-19 drugs with two ATP-binding cassette transporters [P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP)] and potential drug-drug interactions (DDIs) among COVID-19 drugs, especially those associated with P-gp and BCRP efflux transporters.

Expert opinion

Overall, understanding the pharmacodynamic/pharmacokinetic DDIs of COVID-19 drugs can be useful for pharmacological therapy in COVID-19 patients.

Expression heterogeneity of ABC-transporter family genes and chemosensitivity genes in gastric tumor, carcinomatosis and lymph node metastases

Introduction. Metastatic tumors (particularly gastric cancer) have been found to be characterized by heterogeneity between the primary tumor and metastases. This type of heterogeneity comes to the fore when treating primary-metastatic forms of tumor and is an important reason for the low effectiveness of their treatment. In this regard, comparative analysis of ABC-transporter gene expression and chemosensitivity genes will allow to characterize to a certain extent the resistance and sensitivity of primary tumor, carcinomatosis and metastases to therapy and provide the basis for personalized treatment approach.Aim. To evaluate expression heterogeneity of ABC-transporter genes and chemosensitivity genes in gastric tumor, carcinomatosis and lymph node metastases.Materials and methods. Overall 41 patients with disseminated gastric cancer stage IV with carcinomatosis of peritoneum were included in the investigation. All patients underwent surgery according to Roux palliative gastrectomy. After surgery patients underwent chemotherapy depending on indications. RNA was isolated using RNeasy Plus mini kit (Qiagen, Germany). The expression level of ABC transporter genes (ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, ABCG2) and chemosensitivity genes (BRCA1, RRM1, ERCC1, TOP1, TOP2α, TUBβ3, TYMS, GSTP1) was assessed by reverse transcription polymerase chain reaction (RT-PCR) in primary tumor, carcinomatosis and lymph node metastases.Results. The expression levels of the genes under study were shown to vary widely. For ABC transporter genes, ABCG1 (3.1 ± 1.1; max 32.0), ABCG2 (7.9 ± 2.3; max 54.1), ABCG2 (9.6 ± 3.8; max 101.0) were the most expressed genes in gastric tumor tissue, carcinomatosis and lymph node metastasis, respectively. Hyperexpression among chemosensitivity genes at all three sites was characteristic only of TOP2α (17.2 ± 6.0; max. 161.9; 10.8 ± 4.1; max. 105.1; 35.3 ± 0.8; max. 439.6, respectively). We found that TOP2α and BRCA1 gene expression levels were higher in lymph node metastasis compared with gastric tumor tissue and carcinomatosis (at p = 0.005 and p = 0.001). Whereas ABCC1 gene expression was statistically significantly higher in carcinomatosis (p = 0.03).Conclusion. Thus, a high level of expression heterogeneity is observed in gastric cancer, which affects the expression patterns of various genes in different localizations. The expression profile can be used to determine the level of heterogeneity and approach to personalized therapy tactics.

The Tetrahydroisoquinoline Scaffold in ABC Transporter Inhibitors that Act as Multidrug Resistance (MDR) Reversers

BACKGROUND

The failure of anticancer chemotherapy is often due to the development of resistance to a variety of anticancer drugs. This phenomenon is called multidrug resistance (MDR) and is related to the overexpression of ABC transporters, such as P-glycoprotein, multidrug resistance- associated protein 1 and breast cancer resistance protein. Over the past few decades, several ABC protein modulators have been discovered and studied as a possible approach to evade MDR and increase the success of anticancer chemotherapy. Nevertheless, the co-administration of pump inhibitors with cytotoxic drugs, which are substrates of the transporters, does not appear to be associated with an improvement in the therapeutic efficacy of antitumor agents. However, more recently discovered MDR reversing agents, such as the two tetrahydroisoquinoline derivatives tariquidar and elacridar, are characterized by high affinity towards the ABC proteins and by reduced negative properties. Consequently, many analogs of these two derivatives have been synthesized, with the aim of optimizing their MDR reversal properties.

OBJECTIVE

This review aims to describe the MDR modulators carrying the tetraidroisoquinoline scaffold reported in the literature in the period 2009-2021, highlighting the structural characteristics that confer potency and/or selectivity towards the three ABC transport proteins.

RESULTS AND CONCLUSION

Many compounds have been synthesized in the last twelve years showing interesting properties, both in terms of potency and selectivity. Although clear structure-activity relationships can be drawn only by considering strictly related compounds, some of the compounds reviewed could be promising starting points for the design of new ABC protein inhibitors.

Identification of a novel prognostic ADME-related signature associated with tumor immunity for aiding therapy in head and neck squamous cell carcinoma

The genes that control drug absorption, distribution, metabolism, and excretion (ADME) are also involved in carcinogenesis, cancer progression, and chemoresistance. However, no studies have systematically investigated the clinical significance and underlying functions of ADME genes in head and neck squamous cell carcinoma. Herein, we comprehensively explored the ADME genes in this disease, constructed and validated as a prognostic ADME gene signature (ADMEGS), using three ADME genes (ABCB1, ALDH1B1, and PON2) utilizing multiple datasets, including the training and test sets of The Cancer Genome Atlas and the Gene Expression Omnibus validation set. Moreover, we analyzed the relationship between the ADMEGS and clinical parameters, tumor immunity, and therapeutic response. We found that the ADMEGS was significantly correlated with the clinical, T, and N stages. Additionally, we were able to effectively differentiate tumor immune scores, immune cell infiltration statuses, and treatment responses based on the ADMEGS. As such, ADMEGS may be promising predictors for clinical outcome, tumor immunity, and treatment response.

Development of Paeonol Liposomes: Design, Optimization, in vitro and in vivo Evaluation

BACKGROUND

Ulcerative colitis (UC) is one of the intractable diseases recognized by the World Health Organization, and paeonol has been proven to have therapeutic effects. However, the low solubility of paeonol limits its clinical application. To prepare and optimize paeonol liposome, study its absorption mechanism and the anti-inflammatory activity in vitro and in vivo, in order to provide experimental basis for the further development of paeonol into an anti-inflammatory drug in the future.

METHODS

Paeonol loaded liposomes were prepared and optimized by thin film dispersion-ultrasonic method. The absorption mechanism of paeonol-loaded liposomes was studied by pharmacokinetics, in situ single-pass intestinal perfusion and Caco-2 cell monolayer model, the anti-inflammatory activity was studied in a mouse ulcerative model.

RESULTS

Box-Behnken response surface methodology permits to screen the best formulations. The structural and morphological characterization showed that paeonol was entrapped inside the bilayer in liposomes. Pharmacokinetic studies found that the AUC_0-t of Pae-Lips was 2.78 times than that of paeonol suspension, indicating that Pae-Lips significantly improved the absorption of paeonol. In situ single intestinal perfusion and Caco-2 monolayer cell model results showed that paeonol was passively transported and absorbed, and was the substrate of P-gp, MRP2 and BCRP, and the Papp value of Pae-Lips was significantly higher than that of paeonol. In vitro and in vivo anti-inflammatory experiments showed that compared with paeonol, Pae-Lips exhibited excellent anti-inflammatory activity.

CONCLUSION

In this study, Pae-Lips were successfully prepared to improve the oral absorption of paeonol. Absorption may involve passive diffusion and efflux transporters. Moreover, Pae-Lips have excellent anti-inflammatory activity in vitro and in vivo, which preliminarily clarifies the feasibility of further development of Pae-Lips into oral anti-inflammatory drugs.