ASXLs binding to the PHD2/3 fingers of MLL4 provides a mechanism for the recruitment of BAP1 to active enhancers.

The human methyltransferase and transcriptional coactivator MLL4 and its paralog MLL3 are frequently mutated in cancer. MLL4 and MLL3 monomethylate histone H3K4 and contain a set of uncharacterized PHD fingers. Here, we report a novel function of the PHD2 and PHD3 (PHD2/3) fingers of MLL4 and MLL3 that bind to ASXL2, a component of the Polycomb repressive H2AK119 deubiquitinase (PR-DUB) complex. The structure of MLL4 PHD2/3 in complex with the MLL-binding helix (MBH) of ASXL2 and mutational analyses reveal the molecular mechanism which is conserved in homologous ASXL1 and ASXL3. The native interaction of the Trithorax MLL3/4 complexes with the PR-DUB complex in vivo depends solely on MBH of ASXL1/2, coupling the two histone modifying activities. ChIP-seq analysis in embryonic stem cells demonstrates that MBH of ASXL1/2 is required for the deubiquitinase BAP1 recruitment to MLL4-bound active enhancers. Our findings suggest an ASXL1/2-dependent functional link between the MLL3/4 and PR-DUB complexes.

Comparison of Machine Learning Models Using Diffusion-Weighted Images for Pathological Grade of Intrahepatic Mass-Forming Cholangiocarcinoma.

Is the radiomic approach, utilizing diffusion-weighted imaging (DWI), capable of predicting the various pathological grades of intrahepatic mass-forming cholangiocarcinoma (IMCC)? Furthermore, which model demonstrates superior performance among the diverse algorithms currently available? The objective of our study is to develop DWI radiomic models based on different machine learning algorithms and identify the optimal prediction model. We undertook a retrospective analysis of the DWI data of 77 patients with IMCC confirmed by pathological testing. Fifty-seven patients initially included in the study were randomly assigned to either the training set or the validation set in a ratio of 7:3. We established four different classifier models, namely random forest (RF), support vector machines (SVM), logistic regression (LR), and gradient boosting decision tree (GBDT), by manually contouring the region of interest and extracting prominent radiomic features. An external validation of the model was performed with the DWI data of 20 patients with IMCC who were subsequently included in the study. The area under the receiver operating curve (AUC), accuracy (ACC), precision (PRE), sensitivity (REC), and F1 score were used to evaluate the diagnostic performance of the model. Following the process of feature selection, a total of nine features were retained, with skewness being the most crucial radiomic feature demonstrating the highest diagnostic performance, followed by Gray Level Co-occurrence Matrix lmc1 (glcm-lmc1) and kurtosis, whose diagnostic performances were slightly inferior to skewness. Skewness and kurtosis showed a negative correlation with the pathological grading of IMCC, while glcm-lmc1 exhibited a positive correlation with the IMCC pathological grade. Compared with the other three models, the SVM radiomic model had the best diagnostic performance with an AUC of 0.957, an accuracy of 88.2%, a sensitivity of 85.7%, a precision of 85.7%, and an F1 score of 85.7% in the training set, as well as an AUC of 0.829, an accuracy of 76.5%, a sensitivity of 71.4%, a precision of 71.4%, and an F1 score of 71.4% in the external validation set. The DWI-based radiomic model proved to be efficacious in predicting the pathological grade of IMCC. The model with the SVM classifier algorithm had the best prediction efficiency and robustness. Consequently, this SVM-based model can be further explored as an option for a non-invasive preoperative prediction method in clinical practice.

Histone H4K16ac Binding Function of the Triple PHD Finger Cassette of MLL4.

The human methyltransferase MLL4 plays a critical role in embryogenesis and development, and aberrant activity of MLL4 is linked to neurodegenerative and developmental disorders and cancer. MLL4 contains the catalytic SET domain that catalyzes mono methylation of lysine 4 of histone H3 (H3K4me1) and seven plant homeodomain (PHD) fingers, six of which have not been structurally and functionally characterized. Here, we demonstrate that the triple PHD finger cassette of MLL4, harboring its fourth, fifth and sixth PHD fingers (MLL4PHD456) forms an integrated module, maintains the binding selectivity of the PHD6 finger toward acetylated lysine 16 of histone H4 (H4K16ac), and is capable of binding to DNA. Our findings highlight functional correlation between H4K16ac and H3K4me1, two major histone modifications that are recognized and written, respectively, by MLL4.

Iterative-Acting Thioesterase from Polyketide Biosynthesis Accepts Diverse Nucleophilic Alcohols to Yield Oxazole-Containing Esters.

The biosynthesis of antitumor oxazole-containing conglobatin is directed by a multienzyme assembly line of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), in which an uncanonical iterative-acting C-terminal thioesterase domain, Cong-TE, ligated two fully elongated chains/conglobatin monomers on the terminal acylcarrier protein and subsequently cyclized the resulting dimer to a C2-symmetric macrodiolide. Screening of the conglobatin producer for secondary metabolites led to the discovery of two new compounds conglactones A (1) and B (2), possessing inhibitory activities to phytopathogenic microorganisms and cancer cells, respectively. The compounds 1 and 2 feature the ester bond-linked hybrid structures consisting of an aromatic polyketide benwamycin I (3) and one (for 1)/two (for 2) molecules of the conglobatin monomer (5). Genetic mutational analysis revealed that the production of 1 and 2 was correlated with the biosynthetic pathways of 3 and 5. Biochemical analysis indicated that 1 and 2 were produced by Cong-TE from 3 and an N-acetylcysteamine thioester form of 5 (7). Furthermore, the substrate compatibility of Cong-TE was demonstrated by enzymatically generating a bunch of ester products from 7 and 43 exotic alcohols. This property of Cong-TE was further validated by producing 36 hybrid esters in the fermentation of conglobatin producer fed with nonindigenous alcohols. This work shows a prospect of developing Cong-TE for green synthesis of valuable oxazole-containing esters, thus complementing the environmentally unfriendly chemosynthesis strategies.

Signal peptide-CUB-EGF-like repeat-containing protein 1-promoted FLT3 signaling is critical for the initiation and maintenance of MLL-rearranged acute leukemia.

A hallmark of mixed lineage leukemia gene-rearranged (MLL-r) acute myeloid leukemia that offers an opportunity for targeted therapy is addiction to protein tyrosine kinase signaling. One such signal is the receptor tyrosine kinase Fms-like receptor tyrosine kinase 3 (FLT3) upregulated by cooperation of the transcription factors homeobox A9 (HOXA9) and Meis homeobox 1 (MEIS1). Signal peptide-CUB-EGF-like repeat-containing protein (SCUBE) family proteins have previously been shown to act as a co-receptor for augmenting signaling activity of a receptor tyrosine kinase (e.g., vascular endothelial growth factor receptor). However, whether SCUBE1 is involved in the pathological activation of FLT3 during MLL-r leukemogenesis remains unknown. Here we first show that SCUBE1 is a direct target of HOXA9/MEIS1 that is highly expressed on the MLL-r cell surface and predicts poor prognosis in de novo acute myeloid leukemia. We further demonstrate, by using a conditional knockout mouse model, that Scube1 is required for both the initiation and maintenance of MLL-AF9-induced leukemogenesis in vivo. Further proteomic, molecular and biochemical analyses revealed that the membrane-tethered SCUBE1 binds to the FLT3 ligand and the extracellular ligand-binding domains of FLT3, thus facilitating activation of the signal axis FLT3-LYN (a non-receptor tyrosine kinase) to initiate leukemic growth and survival signals. Importantly, targeting surface SCUBE1 by an anti-SCUBE1 monomethyl auristatin E antibody-drug conjugate led to significantly decreased cell viability specifically in MLL-r leukemia. Our study indicates a novel function of SCUBE1 in leukemia and unravels the molecular mechanism of SCUBE1 in MLL-r acute myeloid leukemia. Thus, SCUBE1 is a potential therapeutic target for treating leukemia caused by MLL rearrangements.

New Bioactive Polyacetylenes from the Marine Sponge Petrosia sp.

Three new polyacetylenes, pellynols P (1), Q (2), and R (3) were isolated from the marine sponge Petrosia sp., along with the known compound pellynol H (4). Their structures were determined by analyses of extensive NMR, HR-MS, and ESI-MS/MS data. All compounds displayed potent cytotoxicities against human hepatocellular carcinoma HepG2, human melanoma A375, and human colorectal carcinoma HT29 cell lines with IC50 values at the range of 1.4-4.4 µM.

Axinellasins A-D, Immunosuppressive Cycloheptapeptide Diastereomers, Discovered via a Precursor Ion Scanning-Supercritical Fluid Chromatography Strategy from the Marine Sponge Axinella species.

The precursor ion scanning-supercritical fluid chromatography (PI-SFC) method was applied to explore new methionine sulfoxide-containing cycloheptapeptides, axinellasins A-D (1-4), from the marine sponge Axinella sp. Their structures, including absolute configurations, were elucidated by detailed spectroscopic analyses and X-ray crystallography. The total synthesis of 4 was completed via an Fmoc solid/solution-phase synthesis. Compounds 1-4 exhibited immunosuppressive effects via inhibition of T and B cell proliferation, and 1 and 4 showed better inhibitory activities than their corresponding diastereomers.

Design, synthesis and mechanism studies of novel dual PARP1/BRD4 inhibitors against pancreatic cancer.

Inducing the deficiency of homologous recombination (HR) repair is an effective strategy to broaden the indication of PARP inhibitors in pancreatic cancer treatment. Repression of BRD4 has been reported to significantly elevate HR deficiency and sensitize cancer cells to PARP1/2 inhibitors. Inspired by the concept of synthetic lethality, we designed, synthetized and optimized a dual PARP1/BRD4 inhibitor III-7, with a completely new structure and high selectivity against both targets. III-7 repressed the expression and activity of PARP1 and BRD4 to synergistically inhibit the malignant growth of pancreatic cancer cells in vitro and in vivo. Based on the results of bioinformatic analysis, we found that Olaparib induced the acceleration of mitosis and recovery of DNA repair to cause the generation of drug resistance. III-7 reversed Olaparib-induced adaptive resistance and induced cell cycle arrest and DNA damage by perturbing PARP1 and BRD4-involved signaling pathways. We believe that the PARP1/BRD4 dual inhibitors are novel and promising antitumor agents, which provide an efficient strategy for pancreatic cancer treatment.

Effect of endoscopic radiofrequency ablation on the survival of patients with inoperable malignant biliary strictures: A large cohort study.

BACKGROUND AND AIMS: Endoscopic radiofrequency ablation (RFA) is an emerging technique for the palliation of inoperable malignant biliary strictures (MBSs). We aimed to systemically investigate the long-term outcome of RFA in a large cohort of patients. METHODS: We recruited 883 patients with various MBSs who underwent endoscopic interventions at two large-volume centers; 124 patients underwent RFA and stenting, whereas 759 underwent stenting alone. To overcome selection bias, we performed 1:4 propensity score matching (PSM). The main outcome was overall survival (OS). RESULTS: Following PSM, patients in the RFA group showed significantly longer OS (9.5 months; 95% CI: 7.7-11.3 months) than those in the stenting alone group (6.1 months; 95% CI: 5.6-6.6 months; P < .001). In stratified analyses, the improved OS was only demonstrated in the subgroup of extrahepatic cholangiocarcinoma (11.3 months 95% CI: 10.2-12.4 vs 6.9 months 95% CI: 6.0-7.8; P < .001), but not in the subgroups of gallbladder cancer, hepatocellular carcinoma, intrahepatic cholangiocarcinoma, pancreatic cancer, and other metastatic cancers (all P > .05). The survival benefits were noted only in the patients with non-metastatic cholangiocarcinoma (11.5 vs 7.4 months, P < .001). CONCLUSIONS: The survival benefits of endoscopic RFA appear to be limited to patients with extrahepatic cholangiocarcinoma without distant metastasis.

Antibody array-based proteomic screening of novel biomarkers in malignant biliary stricture.

BACKGROUND: Distinguishing between benign and malignant bile duct strictures has long been a diagnostic challenge in clinical practice. OBJECTIVE: This study aimed to discover novel biomarkers in bile to improve the diagnostic accuracy of malignant biliary strictures. METHODS: Bile samples were collected from 6 patients with malignant or benign biliary stricture, respectively. Protein profiles of the bile were analyzed with a semi-quantitative human antibody array of 440 proteins. Then the differential expressed proteins were screened by Venn diagram analysis. Following this, the accuracy of these potential biomarkers for discriminating between malignant and non-malignant biliary strictures was validated in a larger (n= 40) group of patients using ROC analysis and the best biomarker combination was further selected by lasso analysis. RESULTS: Twenty proteins were found differentially expressed in malignant versus benign biliary strictures, 6 of which were identified by Venn diagram analysis to be up-regulated regardless of the location of biliary strictures. Among the 6 biomarkers, bile lipocalin-2, P-cadherin, and adipsin showed better diagnostic utility than that of bile CA19-9. Lasso analysis identified that lipocalin-2, P-cadherin and CA19-9 as a group of makers best distinguished malignant from benign strictures. CONCLUSIONS: Lipocalin-2 and P-cadherin measurements in bile could be clinically useful for the detection of malignant biliary strictures.

FDI-6 and olaparib synergistically inhibit the growth of pancreatic cancer by repressing BUB1, BRCA1 and CDC25A signaling pathways.

Inducing homologous recombination (HR) deficiency is a promising strategy to broaden the indication of PARP1/2 inhibitors in pancreatic cancer treatment. In addition to inhibition kinases, repression of the transcriptional function of FOXM1 has been reported to inhibit HR-mediated DNA repair. We found that FOXM1 inhibitor FDI-6 and PARP1/2 inhibitor Olaparib synergistically inhibited the malignant growth of pancreatic cancer cells in vitro and in vivo. The results of bioinformatic analysis and mechanistic study showed that FOXM1 directly interacted with PARP1. Olaparib induced the feedback overexpression of PARP1/2, FOXM1, CDC25A, CCND1, CDK1, CCNA2, CCNB1, CDC25B, BRCA1/2 and Rad51 to promote the acceleration of cell mitosis and recovery of DNA repair, which caused the generation of adaptive resistance. FDI-6 reversed Olaparib-induced adaptive resistance and inhibited cell cycle progression and DNA damage repair by repressing the expression of FOXM1, PARP1/2, BUB1, CDC25A, BRCA1 and other genes-involved in cell cycle control and DNA damage repair. We believe that targeting FOXM1 and PARP1/2 is a promising combination therapy for pancreatic cancer without HR deficiency.

FDI-6 inhibits the expression and function of FOXM1 to sensitize BRCA-proficient triple-negative breast cancer cells to Olaparib by regulating cell cycle progression and DNA damage repair.

Inducing homologous-recombination (HR) deficiency is an effective strategy to broaden the indications of PARP inhibitors in the treatment of triple-negative breast cancer (TNBC). Herein, we find that repression of the oncogenic transcription factor FOXM1 using FOXM1 shRNA or FOXM1 inhibitor FDI-6 can sensitize BRCA-proficient TNBC to PARP inhibitor Olaparib in vitro and in vivo. Mechanistic studies show that Olaparib causes adaptive resistance by arresting the cell cycle at S and G2/M phases for HR repair, increasing the expression of CDK6, CCND1, CDK1, CCNA1, CCNB1, and CDC25B to promote cell cycle progression, and inducing the overexpression of FOXM1, PARP1/2, BRCA1/2, and Rad51 to activate precise repair of damaged DNA. FDI-6 inhibits the expression of FOXM1, PARP1/2, and genes involved in cell cycle control and DNA damage repair to sensitize TNBC cells to Olaparib by blocking cell cycle progression and DNA damage repair. Simultaneously targeting FOXM1 and PARP1/2 is an innovative therapy for more patients with TNBC.

Urgent Endoscopy Improves Hemostasis in Patients With Upper Gastrointestinal Bleeding Following Biliary-pancreatic Surgery: A Retrospective Analysis.

BACKGROUND: Upper gastrointestinal bleeding (UGIB) is a lethal complication of biliary-pancreatic surgery (BPS). The role of endoscopic intervention has not been fully defined in such a critical condition. The aim of this study was to assess the efficacy and safety of endoscopic hemostasis in a retrospective cohort. MATERIALS AND METHODS: Consecutive patients with acute UGIB after BPS who received interventional endoscopy between January 2007 and August 2020 were included in this study. The clinical characteristics were collected and analyzed to screen for predictive factors significantly associated with successful hemostasis. RESULTS: Among 37,772 patients who underwent BPS, 26 patients (0.069%) developed acute UGIB. The sites and causes of hemorrhage were as follows: gastroenteric anastomoe (n=17), gastric stump (n=2), jejunal anastomose (n=1), duodenal bulb ulcer (n=2), pancreatojejunal anastomosis hemorrhage (n=1), cholangiojejunal anastomose (n=1), gastroenteric anastomose and gastric stump hemorrhage (n=1), and Dieulafoy lesion (n=1). Successful endoscopic hemostasis was achieved in 19 (73.1%) of the 26 UGIB patients. In the 7 patients who failed endotherapy, 1 patient received a successful radiologic intervention, 6 patients underwent reoperation and achieved hemostasis in 4, and the other 2 patients died after reoperation. Logistic regression analysis showed that presentation-to-endoscopy time (≤12 h) was the only independent predictive factor associated with successful endoscopic hemostasis. CONCLUSIONS: Endoscopic hemostasis is relatively safe and effective in controlling UIGB after BPS. Prompt intervention (≤12 h) could improve the success rate of endoscopic hemostasis.

Discovery of Potent and Novel Dual PARP/BRD4 Inhibitors for Efficient Treatment of Pancreatic Cancer.

Targeting poly(ADP-ribose) polymerase1/2 (PARP1/2) is a promising strategy for the treatment of pancreatic cancer with breast cancer susceptibility gene (BRCA) mutation. Inducing the deficiency of homologous recombination (HR) repair is an effective way to broaden the indication of PARP1/2 inhibitor for more patients with pancreatic cancer. Bromodomain-containing protein 4 (BRD4) repression has been reported to elevate HR deficiency. Therefore, we designed, synthetized, and optimized a dual PARP/BRD4 inhibitor III-16, with a completely new structure and high selectivity against PARP1/2 and BRD4. III-16 showed favorable synergistic antitumor efficacy in pancreatic cancer cells and xenografts by arresting cell cycle progression, inhibiting DNA damage repair, and promoting autophagy-associated cell death. Moreover, III-16 reversed Olaparib-induced acceleration of cell cycle progression and recovery of DNA repair. The advantages of III-16 over Olaparib suggest that dual PARP/BRD4 inhibitors are novel and promising agents for the treatment of advanced pancreatic cancer.

The MLL3/4 H3K4 methyltransferase complex in establishing an active enhancer landscape.

Enhancers are cis-regulatory elements that play essential roles in tissue-specific gene expression during development. Enhancer function in the expression of developmental genes requires precise regulation, while deregulation of enhancer function could be the main cause of tissue-specific cancer development. MLL3/KMT2C and MLL4/KMT2D are two paralogous histone modifiers that belong to the SET1/MLL (also named COMPASS) family of lysine methyltransferases and play critical roles in enhancer-regulated gene activation. Importantly, large-scale DNA sequencing studies have revealed that they are amongst the most frequently mutated genes associated with human cancers. MLL3 and MLL4 form identical multi-protein complexes for modifying mono-methylation of histone H3 lysine 4 (H3K4) at enhancers, which together with the p300/CBP-mediated H3K27 acetylation can generate an active enhancer landscape for long-range target gene activation. Recent studies have provided a better understanding of the possible mechanisms underlying the roles of MLL3/MLL4 complexes in enhancer regulation. Moreover, accumulating studies offer new insights into our knowledge of the potential role of MLL3/MLL4 in cancer development. In this review, we summarize recent evidence on the molecular mechanisms of MLL3/MLL4 in the regulation of active enhancer landscape and long-range gene expression, and discuss their clinical implications in human cancers.

Sesquiterpene lactones of Aucklandia lappa: Pharmacology, pharmacokinetics, toxicity, and structure-activity relationship.

The medicinal part of Aucklandia lappa (Asteraceae) is its dried root, which is one of the commonly used Chinese medicinal materials. Here we reviewed sesquiterpene lactones isolated from A. lappa over the past ten years in the following aspects of pharmacological activities, pharmacokinetics, toxicology, structure-activity relationship. Pharmacological activities consist of anti-cancer, anti-inflammatory activity, anti-immunity activity, anti-oxidant activity, antimicrobial activity, spasmolytic activity and so on. The extractive, showing similar pharmacokinetics parameters, may exert their various biological activities by the interaction of their α-methylene-γ-butyrolactone moiety with the thiol groups of biomacromolecules through Michael-addition. However, the poor aqueous solubility, non-selective binding as a Michael acceptor at undesired targets limited clinical translation of this class. In order to evaluate the potential effect of the extractive applied in clinical trial, the present review outlines information on pharmacological activities, pharmacokinetics, toxicology, and structure-activity relationship, as well as the future research directions of the extractive for further development and utilization of A. lappa.

Cytotoxic meroterpenoids from the marine sponge Dactylospongia elegans.

Three new sesquiterpene quinones/hydroquinones, 20-demethoxy-20-isopentylaminodactyloquinone D (1), 20-demethoxy-20-isobutylaminodactyloquinone D (2), and 19-methoxy-dictyoceratin-A (3), and five known related compounds (4-8) were isolated from the marine sponge Dactylospongia elegans. Their structures were elucidated by spectroscopic analysis, ECD calculation, single-crystal X-ray diffraction, and comparison with the literature. Compounds 3 and 5-8 exhibited activities against the human cancer cell lines DU145, SW1990, Huh7, and PANC-1 with IC50 values ranging from 2.33 to 37.85 µM.

Antimetabolite pemetrexed primes a favorable tumor microenvironment for immune checkpoint blockade therapy.

BACKGROUND: The immune checkpoint blockade (ICB) targeting programmed cell death-1 (PD-1) and its ligand (PD-L1) has been proved beneficial for numerous types of cancers, including non-small-cell lung cancer (NSCLC). However, a significant number of patients with NSCLC still fail to respond to ICB due to unfavorable tumor microenvironment. To improve the efficacy, the immune-chemotherapy combination with pemetrexed, cis/carboplatin and pembrolizumab (anti-PD-1) has been recently approved as first-line treatment in advanced NSCLCs. While chemotherapeutic agents exert beneficial effects, the underlying antitumor mechanism(s) remains unclear. METHODS: Pemetrexed, cisplatin and other chemotherapeutic agents were tested for the potential to induce PD-L1 expression in NSCLC cells by immunoblotting and flow cytometry. The ability to prime the tumor immune microenvironment was then determined by NSCLC/T cell coculture systems and syngeneic mouse models. Subpopulations of NSCLC cells responding differently to pemetrexed were selected and subjected to RNA-sequencing analysis. The key signaling pathways were identified and validated in vitro and in vivo. RESULTS: Pemetrexed induced the transcriptional activation of PD-L1 (encoded by CD274) by inactivating thymidylate synthase (TS) in NSCLC cells and, in turn, activating T-lymphocytes when combined with the anti-PD-1/PD-L1 therapy. Nuclear factor κB (NF-κB) signaling was activated by intracellular reactive oxygen species (ROSs) that were elevated by pemetrexed-mediated TS inactivation. The TS-ROS-NF-κB regulatory axis actively involves in pemetrexed-induced PD-L1 upregulation, whereas when pemetrexed fails to induce PD-L1 expression in NSCLC cells, NF-κB signaling is unregulated. In syngeneic mouse models, the combinatory treatment of pemetrexed with anti-PD-L1 antibody created a more favorable tumor microenvironment for the inhibition of tumor growth. CONCLUSIONS: Our findings reveal novel mechanisms showing that pemetrexed upregulates PD-L1 expression and primes a favorable microenvironment for ICB, which provides a mechanistic basis for the combinatory chemoimmunotherapy in NSCLC treatment.

Dactylospenes A-E, Sesterterpenes from the Marine Sponge Dactylospongia elegans.

Chemical investigation on a marine sponge, Dactylospongia elegans, yielded five new γ-oxygenated butenolide sesterterpene derivatives, dactylospenes A-E (1-5), as well as two known biosynthetically related compounds, luffariellolide (6) and furospinosulin B (7). The structures of these compounds were elucidated on the basis of their spectroscopic data, experimental and calculated electronic circular dichroism (ECD) analysis, as well as comparison of the NMR data with those of known analogs. These metabolites are the first γ-oxygenated butenolide sesterterpenes to be reported from this genus. These compounds were evaluated in antimicrobial, anti-inflammatory, and cytotoxic assays. Only compounds 1, 3, and 6 exhibited moderate cytotoxicity against DU145, SW1990, Huh7, and PANC-1 cancer cell lines with IC50 values in the range of 2.11-13.35 µM. Furthermore, compound 2, without cytotoxicity, exhibited significant inhibitory effects (inhibitory rate 77.5%) on nitric oxide production induced by lipopolysaccharide at 10 µM.

Monocarboxylate Transporter 4 Is a Therapeutic Target in Non-small Cell Lung Cancer with Aerobic Glycolysis Preference.

Targeting metabolic reprogramming is an emerging strategy in cancer therapy. However, clinical attempts to target metabolic reprogramming have been proved to be challenging, with metabolic heterogeneity of cancer being one of many reasons that causes treatment failure. Here, we stratified non-small cell lung cancer (NSCLC) cells, mainly lung adenocarcinoma, based on their metabolic phenotypes and demonstrated that the aerobic glycolysis-preference NSCLC cell subtype was resistant to the OXPHOS-targeting inhibitors. We identified that monocarboxylate transporter 4 (MCT4), a lactate transporter, was highly expressed in the aerobic glycolysis-preference subtype with function supporting the proliferation of these cells. Glucose could induce the expression of MCT4 in these cells through a ΔNp63α and Sp1-dependent pathway. Next, we showed that knockdown of MCT4 increased intracellular lactate concentration and induced a reactive oxygen species (ROS)-dependent cellular apoptosis in the aerobic glycolysis-preference NSCLC cell subtype. By scanning a panel of monoclonal antibodies with MCT4 neutralizing activity, we further identified a MCT4 immunoglobulin M (IgM) monoclonal antibody showing capable anti-proliferation efficacy on the aerobic glycolysis-preference NSCLC cell subtype. Our findings indicate that the metabolic heterogeneity is a critical factor for NSCLC therapy and manipulating the expression or function of MCT4 can be an effective strategy in targeting the aerobic glycolysis-preference NSCLC cell subtype.