Photooxidation triggered ultralong afterglow in carbon nanodots.

It remains a challenge to obtain biocompatible afterglow materials with long emission wavelengths, durable lifetimes, and good water solubility. Herein we develop a photooxidation strategy to construct near-infrared afterglow carbon nanodots with an extra-long lifetime of up to 5.9 h, comparable to that of the well-known rare-earth or organic long-persistent luminescent materials. Intriguingly, size-dependent afterglow lifetime evolution from 3.4 to 5.9 h has been observed from the carbon nanodots systems in aqueous solution. With structural/ultrafast dynamics analysis and density functional theory simulations, we reveal that the persistent luminescence in carbon nanodots is activated by a photooxidation-induced dioxetane intermediate, which can slowly release and convert energy into luminous emission via the steric hindrance effect of nanoparticles. With the persistent near-infrared luminescence, tissue penetration depth of 20 mm can be achieved. Thanks to the high signal-to-background ratio, biological safety and cancer-specific targeting ability of carbon nanodots, ultralong-afterglow guided surgery has been successfully performed on mice model to remove tumor tissues accurately, demonstrating potential clinical applications. These results may facilitate the development of long-lasting luminescent materials for precision tumor resection.

Enteric-coated Mycophenolate Sodium therApy versus cyclophosphamide for induction of Remission in Microscopic PolyAngiitis (EMSAR-MPA trial): study protocol for a randomised controlled trial.

INTRODUCTION: Several studies have demonstrated that mycophenolate mofetil (MMF) may be an excellent alternative to cyclophosphamide (CYC) or rituximab for the induction of remission in non-life-threatening anti-neutrophil cytoplasmic antibodies associated vasculitis because of its strong immunosuppressive potency and low toxicity profile. Enteric-coated mycophenolate sodium (EC-MPS) was introduced to reduce gastrointestinal adverse reactions of MMF. This study will evaluate the efficacy and safety of EC-MPS combined with glucocorticoid in patients with active and non-life-threatening microscopic polyangiitis (MPA). METHODS AND ANALYSIS: This study is a multicentre, open-label, randomised controlled, non-inferiority trial. A total of 110 patients with active and non-life-threatening MPA from 11 hospitals in Shanxi Province of China will be recruited and randomised in a 1:1 ratio to receive either EC-MPS or CYC. All patients will receive the same glucocorticoid plan. We will compare oral EC-MPS (720-1440 mg/day) with intravenous pulsed CYC (7.5-15 mg/kg) administered for 3-6 months. All patients will be switched from their assigned treatment (EC-MPS or CYC) to oral azathioprine (2 mg/kg/day) after remission has been achieved, between 3 and 6 months. Azathioprine will be continued until the study ends at 18 months. The primary end point of efficacy is the remission rate at 6 months. Follow-up will continue for 18 months in order to detect an influence of induction regimen on subsequent relapse rates. ETHICS AND DISSEMINATION: This study has received approval from the Ethics Committee of the Second Hospital of Shanxi Medical University (2022YX-026). All participants are required to provide written informed consent and no study-related procedures will be performed until consent is obtained. The results of this trial will be published in peer-reviewed journals and presented at conferences. TRIAL REGISTRATION NUMBER: ChiCTR2200063823.

Development and evaluation of a human CD47/HER2 bispecific antibody for Trastuzumab-resistant breast cancer immunotherapy.

The treatment for trastuzumab-resistant breast cancer (BC) remains a challenge in clinical settings. It was known that CD47 is preferentially upregulated in HER2+ BC cells, which is correlated with drug resistance to trastuzumab. Here, we developed a novel anti-CD47/HER2 bispecific antibody (BsAb) against trastuzumab-resistant BC, named IMM2902. IMM2902 demonstrated high binding affinity, blocking activity, antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and internalization degradation effects against both trastuzumab-sensitive and trastuzumab-resistant BC cells in vitro. The in vivo experimental data indicated that IMM2902 was more effective than their respective controls in inhibiting tumor growth in a trastuzumab-sensitive BT474 mouse model, a trastuzumab-resistant HCC1954 mouse model, two trastuzumab-resistant patient-derived xenograft (PDX) mouse models and a cord blood (CB)-humanized HCC1954 mouse model. Through spatial transcriptome assays, multiplex immunofluorescence (mIFC) and in vitro assays, our findings provided evidence that IMM2902 effectively stimulates macrophages to generate C-X-C motif chemokine ligand (CXCL) 9 and CXCL10, thereby facilitating the recruitment of T cells and NK cells to the tumor site. Moreover, IMM2902 demonstrated a high safety profile regarding anemia and non-specific cytokines release. Collectively, our results highlighted a novel therapeutic approach for the treatment of HER2+ BCs and this approach exhibits significant anti-tumor efficacy without causing off-target toxicity in trastuzumab-resistant BC cells.

HER2+ advanced gastric cancer: Current state and opportunities (Review).

Human epidermal growth factor receptor 2 (HER2)+ gastric cancer (GC) is a distinct subtype of GC, accounting for 10­20% of all cases of GC. Although the development of the anti­HER2 monoclonal antibody trastuzumab has markedly improved response rates and prognosis of patients with HER2+ advanced GC (AGC), drug resistance remains a considerable challenge. Therefore, dynamic monitoring of HER2 expression levels can facilitate the identification of patients who may benefit from targeted therapy. Besides trastuzumab, DS­8201 and RC48 have been applied in the treatment of HER2+ AGC, and several novel anti­HER2 therapies are undergoing preclinical/clinical trials. At present, combination immunotherapy with anti­HER2 agents is used as the first­line treatment of this disease subtype. New promising approaches such as chimeric antigen receptor T­cell immunotherapy and cancer vaccines are also being investigated for their potential to improve clinical outcomes. The current review provides new insights that will guide the future application of anti­HER2 therapy by summarizing research progress on targeted therapy drugs for HER2+ AGC and combination treatments.

Hemorrhagic stroke-induced subtype of inflammatory reactive astrocytes disrupts blood-brain barrier.

Astrocytes undergo disease-specific transcriptomic changes upon brain injury. However, phenotypic changes of astrocytes and their functions remain unclear after hemorrhagic stroke. Here we reported hemorrhagic stroke induced a group of inflammatory reactive astrocytes with high expression of Gfap and Vimentin, as well as inflammation-related genes lipocalin-2 (Lcn2), Complement component 3 (C3), and Serpina3n. In addition, we demonstrated that depletion of microglia but not macrophages inhibited the expression of inflammation-related genes in inflammatory reactive astrocytes. RNA sequencing showed that blood-brain barrier (BBB) disruption-related gene matrix metalloproteinase-3 (MMP3) was highly upregulated in inflammatory reactive astrocytes. Pharmacological inhibition of MMP3 in astrocytes or specific deletion of astrocytic MMP3 reduced BBB disruption and improved neurological outcomes of hemorrhagic stroke mice. Our study demonstrated that hemorrhagic stroke induced a group of inflammatory reactive astrocytes that were actively involved in disrupting BBB through MMP3, highlighting a specific group of inflammatory reactive astrocytes as a critical driver for BBB disruption in neurological diseases.

Comparative Study of Indocyanine Green Fluorescence Imaging in Lung Cancer with Near-Infrared-I/II Windows.

BACKGROUND: We compare the application of intravenous indocyanine green (ICG) fluorescence imaging in lung cancer with near-infrared-I (NIR-I) and near-infrared-II (NIR-II) windows. METHODS: From March to December 2022, we enrolled patients who received an intravenous injection of ICG (5 mg/kg) 1 day before the planned lung cancer surgery. The lung cancer nodules were imaged by NIR-I/II fluorescence imaging systems, and the tumor-to-normal-tissue ratio (TNR) was calculated. In addition, the fluorescence intensity and signal-to-background ratio (SBR) of capillary glass tubes containing ICG covered with different thicknesses of lung tissue were measured by NIR-I/II fluorescence imaging systems. RESULTS: In this study, 102 patients were enrolled, and the mean age was 59.9 ± 9.2 years. A total of 96 (94.1%) and 98 (96.1%) lung nodules were successfully imaged with NIR-I and NIR-II fluorescence, and the TNR of NIR-II was significantly higher than that of NIR-I (3.9 ± 1.3 versus 2.4 ± 0.6, P < 0.001). In multiple linear regression, solid nodules (P < 0.001) and squamous cell carcinoma (P < 0.001) were independent predictors of a higher TNR of NIR-I/II. When capillary glass tubes were covered with lung tissue whose thickness was more than 2 mm, the fluorescence intensity and the SBR of NIR-II were significantly higher than those of NIR-I. CONCLUSIONS: We verified the feasibility of NIR-II fluorescence imaging in intravenous ICG lung cancer imaging for the first time. NIR-II fluorescence can improve the TNR and penetration depth of lung cancer with promising clinical prospects.

ZnO-incorporated alginate assemblies: Tunable pH-responsiveness and improved drug delivery for cancer therapy.

Delivering drugs selectively to tumor tissues is a significant challenge in cancer therapy, and pH-responsive polymeric assemblies have shown great potential in achieving this goal. In this study, we developed a pH-responsive alginate-based assemblies, called (amine-modified ZnO)-oxidized alginate-PEG ((ZnO-N)-OAl-PEG), for selective drug delivery in cancer treatment. The incorporation of ZnO-N nanoparticles into the alginate-based assemblies enables pH-responsiveness and maintains stability under physiological conditions. At an acidic pH, (ZnO-N)-OAl-PEG disassembles due to the conversion of ZnO to Zn2+, which triggers the unloading of doxorubicin (DOX) from the imine bond between DOX and alginate. This unloading results in the death of cancer cells and inhibition of tumor growth. The anticancer efficacy of (DOX/ZnO-N)-OAl-PEG was demonstrated in vitro and in vivo, providing promising prospects for cancer treatment based on ZnO-induced pH-responsiveness. These findings may also inspire the development of advanced drug delivery systems (DDSs) for cancer therapy.

Excessive nucleic acid R-loops induce mitochondria-dependent epithelial cell necroptosis and drive spontaneous intestinal inflammation.

Oxidative stress, which can be activated by a variety of environmental risk factors, has been implicated as an important pathogenic factor for inflammatory bowel disease (IBD). However, how oxidative stress drives IBD onset remains elusive. Here, we found that oxidative stress was strongly activated in inflamed tissues from both ulcerative colitis patients and Crohn's disease patients, and it caused nuclear-to-cytosolic TDP-43 transport and a reduction in the TDP-43 protein level. To investigate the function of TDP-43 in IBD, we inducibly deleted exons 2 to 3 of Tardbp (encoding Tdp-43) in mouse intestinal epithelium, which disrupted its nuclear localization and RNA-processing function. The deletion gave rise to spontaneous intestinal inflammation by inducing epithelial cell necroptosis. Suppression of the necroptotic pathway with deletion of Mlkl or the RIP1 inhibitor Nec-1 rescued colitis phenotypes. Mechanistically, disruption of nuclear TDP-43 caused excessive R-loop accumulation, which triggered DNA damage and genome instability and thereby induced PARP1 hyperactivation, leading to subsequent NAD+ depletion and ATP loss, consequently activating mitochondrion-dependent necroptosis in intestinal epithelial cells. Importantly, restoration of cellular NAD+ levels with NAD+ or NMN supplementation, as well as suppression of ALKBH7, an α-ketoglutarate dioxygenase in mitochondria, rescued TDP-43 deficiency-induced cell death and intestinal inflammation. Furthermore, TDP-43 protein levels were significantly inversely correlated with γ-H2A.X and p-MLKL levels in clinical IBD samples, suggesting the clinical relevance of TDP-43 deficiency-induced mitochondrion-dependent necroptosis. Taken together, these findings identify a unique pathogenic mechanism that links oxidative stress to intestinal inflammation and provide a potent and valid strategy for IBD intervention.

Eight-Element Dual-Band Multiple-Input Multiple-Output Mobile Phone Antenna for 5G and Wireless Local Area Network Applications.

This paper proposes an eight-element dual-band multiple-input multiple-output (MIMO) antenna that operates in the fifth generation (5G), n78 (3400-3600 MHz), and WLAN (5275-5850 MHz) bands to accommodate the usage scenarios of 5G mobile phones. The eight antenna elements are printed on two long frames, which significantly reduce the usage of the internal space of the mobile phone. Each antenna element is printed on both surfaces of one frame, which consists of a radiator on the internal surface and a defected ground plane on the outer surface. The radiator is a rectangular ring fed by a 50 Ω microstrip line which is printed on the top surface of the system board. A parasitic unit is printed on the outer surface of each frame, which is composed of an inverted H-shaped and four L-shaped patches. Each parasitic unit is connected to the internal surface of the frames through a via, and then it is connected to a 1.5 mm wide microstrip line on the top surface of the system board, which is connected to the ground plane on the bottom surface of the system board by a via. Four L-shaped slots, four rectangular slots, and four U-shaped slots are etched onto the system board, which provides good isolation between the antenna elements. Two merged rectangular rings are printed on the center of each frame, which improves the isolation further. The return loss is better than 6 dB, and the isolation between the units is better than 15 dB in the required working frequency bands. In addition, the use of a defected ground structure not only makes the antenna element obtain better isolation but also improves the overall working efficiency. The measurement results show that the proposed MIMO antenna structure can be an ideal solution for 5G and WLAN applications.

A Miniature Eight-Port Antenna Array Based on Split-Ring Resonators for 5G Sub-6 GHz Handset Applications.

In this article, a miniature eight-port multiple-input multiple-output (MIMO) antenna array is proposed for fifth-generation (5G) sub-6 GHz handset applications. The individual antenna element comprises a radiator shaped like the Chinese character "" (phonetically represented as "Wang") and three split-ring resonators (SRR) on the metal frame. The size of the individual antenna element is only 6.8 × 7 × 1 mm3 (47.6 mm3). The proposed antenna element has a -10 dB impedance bandwidth of 1.7 GHz (from 3.3 GHz to 5 GHz) that can cover 5G New Radio (NR) sub-6 GHz bands N77 (3.3-4.2 GHz), N78 (3.3-3.8 GHz), and N79 (4.4-5 GHz). The evolution design, the current distribution, the effects of single-handed holding, and the analysis of the parameters are deduced to study the approach used to design the featured antenna. The measured total efficiencies are from 40% to 80%, the isolation is better than 12 dB, the calculated envelope correlation coefficient (ECC) is less than 0.12, and the calculated channel capacity (CC) ranges from 35 to 38 bps/Hz. The presented antenna array is a good alternative to 5G mobile handsets with wideband operation, a metal frame, and minimized spacing.

Clinically Translatable Solid-State Dye for NIR-II Imaging of Medical Devices.

Medical devices are commonly implanted underneath the skin, but how to real-time noninvasively monitor their migration, integrity, and biodegradation in human body is still a formidable challenge. Here, the study demonstrates that benzyl violet 4B (BV-4B), a main component in the FDA-approved surgical suture, is found to produce fluorescence signal in the first near-infrared window (NIR-I, 700-900 nm) in polar solutions, whereas BV-4B self-assembles into highly crystalline aggregates upon a formation of ultrasmall nanodots and can emit strong fluorescence in the second near-infrared window (NIR-II, 1000-1700 nm) with a dramatic bathochromic shift in the absorption spectrum of ≈200 nm. Intriguingly, BV-4B-involved suture knots underneath the skin can be facilely monitored during the whole degradation process in vivo, and the rupture of the customized BV-4B-coated silicone catheter is noninvasively diagnosed by NIR-II imaging. Furthermore, BV-4B suspended in embolization glue achieves hybrid fluorescence-guided surgery (hybrid FGS) for arteriovenous malformation. As a proof-of-concept study, the solid-state BV-4B is successfully used for NIR-II imaging of surgical sutures in operations of patients. Overall, as a clinically translatable solid-state dye, BV-4B can be applied for in vivo monitoring the fate of medical devices by NIR-II imaging.

NIR-II fluorescence-guided liver cancer surgery by a small molecular HDAC6 targeting probe.

BACKGROUND: Hepatocellular carcinoma (HCC) is the sixth most common malignancy globally and ranks third in terms of both mortality and incidence rates. Surgical resection holds potential as a curative approach for HCC. However, the residual disease contributes to a high 5-year recurrence rate of 70%. Due to their excellent specificity and optical properties, fluorescence-targeted probes are deemed effective auxiliary tools for addressing residual lesions, enabling precise surgical diagnosis and treatment. Research indicates histone deacetylase 6 (HDAC6) overexpression in HCC cells, making it a potential imaging biomarker. This study designed a targeted small-molecule fluorescent probe, SeCF3-IRDye800cw (SeCF3-IRD800), operating within the Second near-infrared window (NIR-II, 1000-1700 nm). The study confirms the biocompatibility of SeCF3-IRD800 and proceeds to demonstrate its applications in imaging in vivo, fluorescence-guided surgery (FGS) for liver cancer, liver fibrosis imaging, and clinical samples incubation, thereby preliminarily validating its utility in liver cancer. METHODS: SeCF3-IRD800 was synthesized by combining the near-infrared fluorescent dye IRDye800cw-NHS with an improved HDAC6 inhibitor. Initially, a HepG2-Luc subcutaneous tumor model (n = 12) was constructed to investigate the metabolic differences between SeCF3-IRD800 and ICG in vivo. Subsequently, HepG2-Luc (n = 12) and HCCLM3-Luc (n = 6) subcutaneous xenograft mouse models were used to assess in vivo targeting by SeCF3-IRD800. The HepG2-Luc orthotopic liver cancer model (n = 6) was employed to showcase the application of SeCF3-IRD800 in FGS. Liver fibrosis (n = 6) and HepG2-Luc orthotopic (n = 6) model imaging results were used to evaluate the impact of different pathological backgrounds on SeCF3-IRD800 imaging. Three groups of fresh HCC and normal liver samples from patients with liver cancer were utilized for SeCF3-IRD800 incubation ex vivo, while preclinical experiments illustrated its potential for clinical application. FINDINGS: The HDAC6 inhibitor 6 (SeCF3) modified with trifluoromethyl was labeled with IRDy800CW-NHS to synthesize the small-molecule targeted probe SeCF3-IRD800, with NIR-II fluorescence signals. SeCF3-IRD800 was rapidly metabolized by the kidneys and exhibited excellent biocompatibility. In vivo validation demonstrated that SeCF3-IRD800 achieved optimal imaging within 8 h, displaying high tumor fluorescence intensity (7658.41 ± 933.34) and high tumor-to-background ratio (5.20 ± 1.04). Imaging experiments with various expression levels revealed its capacity for HDAC6-specific targeting across multiple HCC tumor models, suitable for NIR-II intraoperative imaging. Fluorescence-guided surgery experiments were found feasible and capable of detecting sub-visible 2 mm tumor lesions under white light, aiding surgical decision-making. Further imaging of liver fibrosis mice showed that SeCF3-IRD800's imaging efficacy remained unaffected by liver pathological conditions. Correlations were observed between HDAC6 expression levels and corresponding fluorescence intensity (R2 = 0.8124) among normal liver, liver fibrosis, and HCC tissues. SeCF3-IRD800 identified HDAC6-positive samples from patients with HCC, holding advantages for perspective intraoperative identification in liver cancer. Thus, the rapidly metabolized HDAC6-targeted small-molecule NIR-II fluorescence probe SeCF3-IRD800 holds significant clinical translational value. INTERPRETATION: The successful application of NIR-II fluorescence-guided surgery in liver cancer indicates that SeCF3-IRD800 has great potential to improve the clinical diagnosis and treatment of liver cancer, and could be used as an auxiliary tool for surgical treatment of liver cancer without being affected by liver pathology. FUNDING: This paper is supported by the National Natural Science Foundation of China (NSFC) (92,059,207, 62,027,901, 81,930,053, 81,227,901, 82,272,105, U21A20386 and 81,971,773), CAS Youth Interdisciplinary Team (JCTD-2021-08), the Zhuhai High-level Health Personnel Team Project (Zhuhai HLHPTP201703), and Guangdong Basic and Applied Basic Research Foundation under Grant No. 2022A1515011244.

The C-type lectin COLEC10 is predominantly produced by hepatic stellate cells and involved in the pathogenesis of liver fibrosis.

Hepatic stellate cell is one of the major nonparenchymal cell types in liver. It has been proved the hepatic stellate cells are activated upon liver injury and produce excessive extracellular matrix to induce liver fibrosis. Single-cell RNA sequencing has been introduced to identify the subpopulations and function of hepatic stellate cells for its remarkable resolution of representation of single-cell transcriptome. According to the re-analysis of single-cell RNA sequencing data and pseudotime trajectory inference, we have found the C-type lectins including Colec10 and Colec11 are not produced by hepatocytes but predominantly produced by hepatic stellate cells, especially quiescent ones in the mice livers. In addition, the expression of Colec10 is decreased in the fibrotic livers of CCl4-challenged mice. COLEC10 is also mainly expressed in the hepatic stellate cells of human livers and the expression of COLEC10 is decreased with the progression of liver fibrosis. The bulk RNA sequencing data of the lentivirus transfected LX-2 cells indicates the function of COLEC10 is associated with inflammation, angiogenesis and extracellular matrix alteration. Surprisingly, the in vitro overexpression of COLEC10 in LX-2 cells promotes the mRNA expression of extracellular matrix components including COL1A1, COL1A2 and COL3A1 and the extracellular matrix degradation enzyme MMP2. To further investigate the role of COLEC10 in the pathogenesis of liver fibrosis, the serum concentration of COLEC10 in patients with chronic liver disease and healthy donors is measured. The serum concentration of COLEC10 is elevated in the patients with chronic liver disease compared to the healthy donors and positively correlated with serum concentration of the D-dimer but not the most of liver function markers. Altogether, we conclude that the C-type lectin COLEC10 is predominantly produced by the hepatic stellate cells and involved in the pathogenesis of liver fibrosis.

An NIR-II Probe with High PSMA Affinity Demonstrates an Unexpected Excellent Bone Imaging Ability.

(S)-3-(Carboxyformamido)-2-(3-(carboxymethyl)ureido)propanoic acid (EuK) is a known binder toward the prostate-specific membrane agent (PSMA) with strong affinity, making it a popular choice for prostate cancer medicine development. However, during the probe modification, a new EuK-based PSMA tetramer, Bone-1064, was discovered to have an unexpected and intense uptake in bone, which has not yet been reported in any previous studies yet. After administration, Bone-1064 allowed for high contrast visualization of the bone from surrounding tissues with a signal-to-background ratio of 10.22 at 24 h postinjection. In contrast, the tumor had a blurry contour, and the maximum tumor-to-normal-tissue ratio was only 2.22. Further imaging studies revealed that Bone-1064 binds specifically to hydroxyapatite in bone tissues, instead of PSMA. Overall, Bone-1064 is an excellent bone probe with a unique structure that can be used for NIR-II fluorescence imaging in animal models. Meanwhile, this modification study might also inspire further PSMA probe designations.

Bio-clickable, small extracellular vesicles-COCKTAIL therapy for ischemic stroke.

Delivering large therapeutic molecules via the blood-brain barrier to treat ischemic stroke remains challenging. NR2B9c is a potent neuroprotective peptide but it's safe and targeted delivery to the brain requires an efficient, natural, and non-immunogenic delivery technique. Small extracellular vesicles (sEVs) have shown great potential as a non-immunogenic, natural cargo delivery system; however, tailoring of its inefficient brain targeting is desired. Here, we coupled rabies virus glycoprotein 29 with sEVs surface via bio-orthogonal click chemistry reactions, followed by loading of NR2B9c, ultimately generating stroke-specific therapeutic COCKTAIL (sEVs-COCKTAIL). Primary neurons and Neuro-2a cells were cultured for in vitro and transient middle cerebral artery occlusion model was used for in vivo studies to evaluate neuron targeting and anti-ischemic stroke potential of the sEVs-COCKTAIL. Bio-clickable sEVs were selectively taken up by neurons but not glial cells. In the in vitro ischemic stroke model of oxygen-glucose deprivation, the sEVs-COCKTAIL exhibited remarkable potential against reactive oxygen species and cellular apoptosis. In vivo studies further demonstrated the brain targeting and increased half-life of bio-clickable sEVs, delivering NR2B9c to the ischemic brain and reducing stroke injury. Treatment with the sEVs-COCKTAIL significantly increased behavioral recovery and reduced neuronal apoptosis after transient middle cerebral artery occlusion. NR2B9c was delivered to neurons binding to post-synaptic density protein-95, inhibiting N-methyl-d-Aspartate receptor-mediated over production of oxidative stress and mitigating protein B-cell lymphoma 2 and P38 proteins expression. Our results provide an efficient and biocompatible approach to a targeted delivery system, which is a promising modality for stroke therapy.

hMOF induces cisplatin resistance of ovarian cancer by regulating the stability and expression of MDM2.

Histone acetyltransferase human males absent on the first (hMOF) is a member of MYST family which participates in posttranslational chromatin modification by controlling the acetylation level of histone H4K16. Abnormal activity of hMOF occurs in multiple cancers and biological alteration of hMOF expression can affect diverse cellular functions including cell proliferation, cell cycle progression and embryonic stem cells (ESCs) self-renewal. The relationship between hMOF and cisplatin resistance was investigated in The Cancer Genome Atlas (TCGA) and Genomics of Drug Sensitivity in Cancer (GDSC) database. Lentiviral-mediated hMOF-overexpressed cells or hMOF-knockdown cells were established to investigate its role on cisplatin-based chemotherapy resistance in vitro ovarian cancer cells and animal models. Furthermore, a whole transcriptome analysis with RNA sequencing was used to explore the underlying molecular mechanism of hMOF affecting cisplatin-resistance in ovarian cancer. The data from TCGA analysis and IHC identification demonstrated that hMOF expression was closely associated with cisplatin-resistance in ovarian cancer. The expression of hMOF and cell stemness characteristics increased significantly in cisplatin-resistant OVCAR3/DDP cells. In the low hMOF expressing ovarian cancer OVCAR3 cells, overexpression of hMOF improved the stemness characteristics, inhibited cisplatin-induced apoptosis and mitochondrial membrane potential impairment, as well as reduced the sensitivity of OVCAR3 cells to cisplatin treatment. Moreover, overexpression of hMOF diminished tumor sensitivity to cisplatin in a mouse xenograft tumor model, accompanied by decrease in the proportion of cisplatin-induced apoptosis and alteration of mitochondrial apoptosis proteins. In addition, opposite phenotype and protein alterations were observed when knockdown of hMOF in the high hMOF expressing ovarian cancer A2780 cells. Transcriptomic profiling analysis and biological experimental verification orientated that MDM2-p53 apoptosis pathway was related to hMOF-modulated cisplatin resistance of OVCAR3 cells. Furthermore, hMOF reduced cisplatin-induced p53 accumulation by stabilizing MDM2 expression. Mechanistically, the increased stability of MDM2 was due to the inhibition of ubiquitinated degradation, which resulted by increased of MDM2 acetylation levels by its direct interaction with hMOF. Finally, genetic inhibition MDM2 could reverse hMOF-mediated cisplatin resistance in OVCAR3 cells with up-regulated hMOF expression. Meanwhile, treatment with adenovirus expressing shRNA of hMOF improved OVCAR3/DDP cell xenograft sensitivity to cisplatin in mouse. Collectively, the results of the study confirm that MDM2 as a novel non-histone substrate of hMOF, participates in promoting hMOF-modulated cisplatin chemoresistance in ovarian cancer cells. hMOF/MDM2 axis might be a potential target for the treatment of chemotherapy-resistant ovarian cancer.

Discovery of Novel 1,3-Diphenylpyrazine Derivatives as Potent S-Phase Kinase-Associated Protein 2 (Skp2) Inhibitors for the Treatment of Cancer.

F-box protein S-phase kinase-associated protein 2 (Skp2) is a component of cullin-RING ligases, which is responsible for recruiting and ubiquitinating substrates and subsequently plays its proteolytic and non-proteolytic role. High expression of Skp2 is frequently observed in multiple aggressive tumor tissues and associated with poor prognosis. Several of the Skp2 inhibitors have been reported in the last decades; however, few of them have shown detailed structure-activity relationship (SAR) and potent bioactivity. Herein, based on the hit compound 11a from our in-house library, we optimize and synthesize a series of new 2,3-diphenylpyrazine-based inhibitors targeting the Skp2-Cks1 interaction and further systematically study the SAR. Among them, compound 14i shows potent activity against the Skp2-Cks1 interaction with an IC50 value of 2.8 µM and against PC-3 and MGC-803 cells with IC50 values of 4.8 and 7.0 µM, respectively. Most importantly, compound 14i exhibited effectively anticancer effects on PC-3 and MGC-803 xenograft mice models without obvious toxicity.

Discovery of novel, potent, and orally bioavailable HDACs inhibitors with LSD1 inhibitory activity for the treatment of solid tumors.

Histone deacetylases (HDACs) and lysine-specific demethylase 1 (LSD1) are attractive targets for epigenetic cancer therapy. There is an intimate interplay between the two enzymes. HDACs inhibitors have shown synergistic anticancer effects in combination with LSD1 inhibitors in several types of cancer. Herein, we describe the discovery of compound 5e, a highly potent HDACs inhibitor (HDAC1/2/6/8; IC50 = 2.07/4.71/2.40/107 nM) with anti-LSD1 potency (IC50 = 1.34 µM). Compound 5e exhibited marked antiproliferative activity in several cancer cell lines. 5e effectively induced mitochondrial apoptosis with G2/M phase arrest, inhibiting cell migration and invasion in MGC-803 and HCT-116 cancer cells. It also showed good liver microsomal stability and acceptable pharmacokinetic parameters in SD rats. More importantly, orally administered compound 5e demonstrated higher in vivo antitumor efficacy than SAHA in the MGC-803 (TGI = 71.5%) and HCT-116 (TGI = 57.6%) xenograft tumor models accompanied by good tolerability. This study provides a novel lead compound with dual inhibitory activity against HDACs and LSD1 to further develop epigenetic drugs for solid tumor therapy. Further optimization is needed to improve the LSD1 activity to achieve dual inhibitors with balanced potency on LSD1 and HDACs.