Inhibition of PCSK9 potentiates immune checkpoint therapy for cancer.

Despite its success in achieving the long-term survival of 10-30% of treated individuals, immune therapy is still ineffective for most patients with cancer1,2. Many efforts are therefore underway to identify new approaches that enhance such immune 'checkpoint' therapy3-5 (so called because its aim is to block proteins that inhibit checkpoint signalling pathways in T cells, thereby freeing those immune cells to target cancer cells). Here we show that inhibiting PCSK9-a key protein in the regulation of cholesterol metabolism6-8-can boost the response of tumours to immune checkpoint therapy, through a mechanism that is independent of PCSK9's cholesterol-regulating functions. Deleting the PCSK9 gene in mouse cancer cells substantially attenuates or prevents their growth in mice in a manner that depends on cytotoxic T cells. It also enhances the efficacy of immune therapy that is targeted at the checkpoint protein PD1. Furthermore, clinically approved PCSK9-neutralizing antibodies synergize with anti-PD1 therapy in suppressing tumour growth in mouse models of cancer. Inhibiting PCSK9-either through genetic deletion or using PCSK9 antibodies-increases the expression of major histocompatibility protein class I (MHC I) proteins on the tumour cell surface, promoting robust intratumoral infiltration of cytotoxic T cells. Mechanistically, we find that PCSK9 can disrupt the recycling of MHC I to the cell surface by associating with it physically and promoting its relocation and degradation in the lysosome. Together, these results suggest that inhibiting PCSK9 is a promising way to enhance immune checkpoint therapy for cancer.

XDL-ESI: Electrophysiological Sources Imaging via explainable deep learning framework with validation on simultaneous EEG and iEEG.

Electroencephalography (EEG) or Magnetoencephalography (MEG) source imaging aims to estimate the underlying activated brain sources to explain the observed EEG/MEG recordings. Solving the inverse problem of EEG/MEG Source Imaging (ESI) is challenging due to its ill-posed nature. To achieve a unique solution, it is essential to apply sophisticated regularization constraints to restrict the solution space. Traditionally, the design of regularization terms is based on assumptions about the spatiotemporal structure of the underlying source dynamics. In this paper, we propose a novel paradigm for ESI via an Explainable Deep Learning framework, termed as XDL-ESI, which connects the iterative optimization algorithm with deep learning architecture by unfolding the iterative updates with neural network modules. The proposed framework has the advantages of (1) establishing a data-driven approach to model the source solution structure instead of using hand-crafted regularization terms; (2) improving the robustness of source solutions by introducing a topological loss that leverages the geometric spatial information applying varying penalties on distinct localization errors; (3) improving the reconstruction efficiency and interpretability as it inherits the advantages from both the iterative optimization algorithms (interpretability) and deep learning approaches (function approximation). The proposed XDL-ESI framework provides an efficient, accurate, and interpretable paradigm to solve the ESI inverse problem with satisfactory performance in both simulated data and real clinical data. Specially, this approach is further validated using simultaneous EEG and intracranial EEG (iEEG).

Validation and comparison of 5th edition World Health Organization classification (WHO 2022) and International Consensus Classification proposals for MDS-SFB31.

The criteria of myelodysplastic syndromes (MDS) with mutated SFB31 (MDS-SFB31) proposed by the 5th edition of the WHO classification (WHO 2022) and the International Consensus Classification (ICC) need validation. We analysed 125 consecutive MDS cases with SFB31 mutation or ring sideroblasts (RS) ≥15% without excess blasts. We found that SFB31-negative MDS with RS had significantly different clinical features and worse prognosis. According to WHO 2022, the detection of ≥15% RS may substitute for SF3B1 mutation and our analyses support this proposal for similar prognosis of two groups after excluding high-risk genetic features referred by WHO 2022. Patients with variant allele frequency (VAF) <10% SFB31 tend to have briefer survival, supporting the VAF 10% threshold of ICC. Patients with multilineage dysplasia (MLD) had significantly shorter OS than those with single lineage dysplasia. MLD is still a powerful morphological marker of worse outcome in WHO 2022 and ICC-defined MDS-SF3B1.

Identification of miR-1-3p, miR-143-3p and miR-145-5p association with bone metastasis of Gleason 3+4 prostate cancer and involvement of LASP1 regulation.

Gleason Score (GS) 3 + 4 prostate cancer (PCa) is heterogeneous in clinical course and molecular features. Risk stratification of indolent and aggressive PCa with GS 3 + 4 is critical, especially those with bone metastasis (BM) potential. Microarray-based microRNA(miRNA) profiling with eight PCa cases with or without BM was used to screen the candidate miRNAs associated with BM. Transwell and MTS assays were used to characterize the function of miRNAs and target gene LASP1. RT-qPCR and immunohistochemistry assays were utilized to illustrate the clinical significance of miRNAs and target gene in a cohort of 309 Chinese PCa cases. In the current study, we identified that miR-1-3p, miR-143-3p and miR-145-5p are associated with BM of GS 3 + 4 PCa. Through functional experiments, we show that miR-1-3p/143-3p/145-5p promotes proliferation and migration of PCa in vitro. LASP1 was predicted as the common target of these three miRNAs which was further confirmed by a luciferase assay. Overexpression of LASP1 was correlated with higher GS, higher pathological stage, and the presence of metastasis by immunohistochemistry. siRNA knockdown of LASP1 significantly suppressed proliferation and migration, whereas overexpression of LASP1 promoted it. Bioinformatics analysis revealed the involvement of Wnt signaling pathway in LASP1 mediated function. LASP1 may activate Wnt signaling by interacting with ß-catenin. In all, we suggest that miR-1-3p/143-3p/145-5p are associated with BM of Gleason 3 + 4 PCa. LASP1 is the common target of these miRNAs and may active Wnt signaling by interacting with ß-catenin.

Clinical effects of Chemotherapy combined with Immunotherapy in patients with advanced NSCLC and the effect on their nutritional status and immune function.

Objectives: To evaluate the clinical effects of chemotherapy combined with immunotherapy in patients with advanced non-small-cell lung cancer (NSCLC) and the effect on their nutritional status and immune function. Methods: Total 120 patients with advanced NSCLC admitted to Affiliated Hospital of Hebei University from May 2019 to October 2021 were randomly divided into two groups (n= 60, respectively). Patients in the control group were treated by chemotherapy with cisplatin-paclitaxel (TP) alone: 120 mg/m2 paclitaxel was used on d1; and 25mg/m2 cisplatin (CDDP) was used for more than two hour, once every 14 days, for three consecutive three cycles. Patients in the study group were additionally given 200 mg sindilizumab by intravenous drip, once every three weeks. The contrastive analysis of clinical effects, the incidence of adverse reactions, improvement of the nutrient index and the changes in levels of CD3+, CD4+, CD8+, and CD4+/CD8+ in T-lymphocyte subsets was performed between the two groups. Result: The overall response rate (ORR) was 80% and 61% in the study group and the control group, respectively; and the difference was statistically significant (p=0.03); the contrast analysis of the incidence of post-treatment adverse drug reactions (ADRs) in patients in the two groups suggested that the incidence of adverse reactions was 33.3% and 45% in the study group and the control group, respectively; and the difference was not statistically significant (p=0.19). After the treatment, the improvement of hemoglobin, albumin, serum iron and ferritin levels in the study group was more significant than that in the control group; and the difference was statistically significant (p < 0.05). After the treatment, the levels of CD3+, CD4+ and CD4+/CD8+ in the study group were much higher than those in the control group; and the difference was statistically significant (p < 0.05). Conclusion: Chemotherapy combined with immunotherapy is effective in treating patients with advanced NSCLC without increasing the incidence of adverse reactions, and can significantly improve their nutritional status and T-lymphocyte function. This therapeutic regimen is of much higher clinical value than the chemotherapy-only regimen.

The first high-quality chromosome-level genome assembly of Phyllanthaceae (Phyllanthus cochinchinensis) provides insights into flavonoid biosynthesis.

MAIN CONCLUSION: We report the genome assembly of P. cochinchinensis, as the first high-quality chromosome-level genome of Phyllanthaceae which is rich in medicinal plants. Phyllanthus cochinchinensis, a member of the Phyllanthaceae, is one of the famous medicinal plants in South China. Here, we report a de novo chromosome-level genome assembly for P. cochinchinensis using a combination of Nanopore and Illumina sequencing technologies. In total, the assembled genome consists of 284.88 Mb genomic sequences with a contig N50 of 10.32 Mb, representing ~ 95.49% of the estimated genome size. By applying Hi-C data, 13 pseudochromosomes of P. cochinchinensis were constructed, covering ~ 99.87% of the assembled sequences. The genome is annotated with 59.12% repetitive sequences and 20,836 protein-coding genes. Whole-genome duplication of P. cochinchinensis is likely shared with Ricinus communis as well as Vitis vinifera. Homologous genes within the flavonoid pathway for P. cochinchinensis were identified and copy numbers and expression level of related genes revealed potential critical genes involved in flavonoid biosynthesis. This study provides the first whole-genome sequence for the Phyllanthaceae, confirms the evolutionary status of Phyllanthus from the genomic level, and provides foundations for accelerating functional genomic research of species from Phyllanthus.

Identification and Quantification of Nanoplastics in Surface Water and Groundwater by Pyrolysis Gas Chromatography-Mass Spectrometry.

Nanoplastics (NPs) are currently considered an environmental pollutant of concern, but the actual extent of NP pollution in environmental water bodies remains unclear and there is not enough quantitative data to conduct proper risk assessments. In this study, a pretreatment method combining ultrafiltration (UF, 100 kDa) with hydrogen peroxide digestion and subsequent detection with pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) was developed and used to identify and quantify six selected NPs in surface water (SW) and groundwater (GW), including poly(vinylchloride) (PVC), poly(methyl methacrylate) (PMMA), polypropylene (PP), polystyrene (PS), polyethylene (PE), and poly(ethylene terephthalate) (PET). The results show that the proposed method could detect NPs in environmental water samples. Nearly all selected NPs could be detected in the surface water at all locations, while PVC, PMMA, PS, and PET NPs were frequently below the detection limit in the groundwater. PP (32.9-69.9%) and PE (21.3-44.3%) NPs were the dominant components in both surface water and groundwater, although there were significant differences in the pollution levels attributed to the filtration efficiency of riverbank, with total mass concentrations of 0.283-0.793 µg/L (SW) and 0.021-0.203 µg/L (GW). Overall, this study quantified the NPs in complex aquatic environments for the first time, filling in gaps in our knowledge about NP pollution levels and providing a useful methodology and important reference data for future research.

Mangrove forest: An important coastal ecosystem to intercept river microplastics.

The research on transportation of river microplastics (MPs) mainly focuses on the estimations of the total contents of river MPs entering the ocean, while the related transportation processes and influence factors were still largely unknown. In our study, the role of mangrove forest, a special tropical ecosystem in the estuary, on the transportations of MPs from rivers to ocean was explored. Except for the ND river with the absence of mangrove forest, the MPs collected from the water sample of the river upstream were much higher than their corresponding downstream (p < 0.05), with the interception rate of riverine MPs by mangrove forests ranging from 12.86% to 56% in dry season and 10.57%-42% in rainy season. The MPs with the characteristics of high density, larger size and regular shape were more easily intercepted. Furthermore, the combined effects of ecological indicators, the properties of mangrove and the hydrodynamic factors jointly determined the interception rates of MPs. This study provides a new perspective and data support for quantifying mangrove forests intercepting MPs in rivers as a factor of MPs retention in global rivers.

[Clinical characteristics and genetic analysis of a Chinese pedigree affected with tuberous sclerosis complex].

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with tuberous sclerosis complex (TSC). METHODS: The TSC1 and TSC2 genes were sequenced. Candidate variant was verified by Sanger sequencing of the proband and her family members. Pathogenicity of the variant was predicted based on the American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS: The proband was found to harbor a heterozygous c.52delC frameshift variant of the TSC2 gene, which may result in synthesis of amino acid chain starting from the 18th amino acid Leu and terminating at the 28th amino acid (p.Leu18CysfsTer28). The variant was unreported in the public database. Mutation Taster software predicted that the variant is harmful. Both parents of the proband were of the wild type, suggesting that the variant has occurred de novo. Based on the ACMG guidelines, the variant was predicted to be likely pathogenic (PVS1 +PM2). CONCLUSION: A novel pathogenic variant of the TSC2 gene c.52delC (p.Leu18CysfsTer28) was identified, which has enriched the mutational spectrum of TSC2 and provided a basis for genetic counseling for this pedigree.

Effect of ß-Blocker Therapy on the Level of Soluble ST2 Protein in Pediatric Dilated Cardiomyopathy.

Background and Objectives: A prognosis for kids with pediatric dilated cardiomyopathy (PDCM) is urgently needed to identify high-risk patients. This study aimed to determine the association of levels and soluble suppression of tumorigenicity 2 (sST2) and medical therapy of ß-blocker inhibitors with the risk of adverse events in PDCM. Materials and Methods: A total of 124 patients with PDCM were enrolled after admission from 2 centers in China and followed up for adverse events (death, cardiac transplantation, and heart-failure-related rehospitalization). Based on a median sST2 level and the usage of ß-blocker inhibitors, patients were divided into four groups. The Cox proportional hazard model was used to assess the risk of incident adverse events. Results: The median level of sST2 was 23.77 ng/mL, and 53 (42.7%) patients received ß-blocker treatment. Over a median follow-up of 678 days, 37 (29.8%) adverse events occurred. Compared with patients with sST2 < median and without ß-blocker, patients with sST2 ≥ median and without ß-blocker (HR: 7.01; 95% CI: 1.21−40.45), followed by those with sST2 ≥ median and use of ß-blocker had the highest risk of adverse events (hazard ratio (HR): 5.51; 95% confidence interval (CI): 1.17−25.84). However, a significant association was not observed in patients with sST2 < median and use of ß-blocker. These associations were consistent across different subgroups. Conclusions: A higher level of sST2 was associated with a higher risk of adverse events in patients with PDCM, and ß-blocker treatment for children with high levels of sST2 can effectively avoid adverse events.

Is race important in genomic classification of hematological neoplasms?

In recent years, genome-based classifications for hematological neoplasms have been proposed successively and proved to be more accurate than histologic classifications. However, some previous studies have reported the racial differences of genetic landscape in persons with hematological neoplasms including myelodysplastic syndromes (MDS), which may cause a genomic classification based on a particular ethnic group does not operate in other races. To determine whether race plays an important role in the genomic-based classification, we validated a newly proposed genomic classification of MDS (J Clin Oncol.2021; JCO2001659), which was based on a large European database, in Chinese patients from our center. Our results showed significant differences between Chinese and European patients including proportion of each group to overall cohort when applying this novel genomic classification. Our data indicate that a genomic classification of hematological neoplasms probably should be revised according to specific genetic features in different races.

2-Methoxyestradiol synergizes with Erlotinib to suppress hepatocellular carcinoma by disrupting the PLAGL2-EGFR-HIF-1/2α signaling loop.

Erlotinib, an EGFR tyrosine kinase inhibitor has been introduced into cancer chemotherapy. However, the therapeutic effects of erlotinib in hepatocellular carcinoma (HCC) remain vaguely understood. Our previous study found that a hypoxia-mediated PLAGL2-EGFR-HIF-1/2α signaling loop in HCC decreased response to erlotinib. The current study has demonstrated that the combination of erlotinib and 2ME2 exerted synergistic antitumor effects against HCC. Further investigation showed that erlotinib increased the expression level of EGFR, HIF-2α, and PLAGL2, which contributes to the insensitivity of hypoxic HCC cells to erlotinib. The simultaneous exposure to 2ME2 effectively inhibited the expression level of EGFR, HIF-2α, and PLAGL2 that was induced by erlotinib. This contributes to the synergistic effect of the two therapeutic agents. Furthermore, the combination of erlotinib and 2ME2 induced apoptosis and inhibited the stemness of hypoxic HCC cells. Our findings potentially explain the mechanism of HCC insensitivity to erlotinib and provide a new strategy of combining EGFR and HIF1/2α inhibitors for HCC treatment.

Visible-Light-Promoted Multistep Tandem Reaction of Vinyl Azides toward the Formation of 1-Tetralones.

A visible-light-driven multistep tandem reaction between vinyl azides and alkyl bromides has been developed leading to the formation of tetralone skeletons under mild conditions, which can be easily scaled up to the gram scale. Various 1-tetralone derivatives are synthesized and transformed into desired products in good to high yields.

Ratiometric sensing of butyrylcholinesterase activity based on the MnO2 nanosheet-modulated fluorescence of sulfur quantum dots and o-phenylenediamine.

Butyrylcholinesterase (BChE) can modulate the expression level of cholinesterase, which emerges as an important clinical diagnose index. However, the currently reported assays for BChE are suffering from the problem of interferences. A ratiometric fluorescence assay was developed based on the MnO2 nanosheet (NS)-modulated fluorescence of sulfur quantum dots (S-dots) and o-phenylenediamine (OPD). MnO2 NS can not only quench the fluorescence of blue emissive S-dots, but also enhance the yellow emissive OPD by catalyzing its oxidation reactions. Upon introducing BChE and substrate into the system, their hydrolysate can reduce MnO2 into Mn2+, leading to the fluorescence recovery of S-dots and failure of OPD oxidation. BChE activity can be quantitatively detected by recording the change of fluorescence signals in the blue and yellow regions. A linear relationship is observed between the ratio of F435/F560 and the concentration of BChE in the range 30 to 500 U/L, and a limit of detection of 17.8 U/L has been calculated. The ratiometric fluorescence assay shows an excellent selectivity to acetylcholinesterase and tolerance to various other species. The method developed  provides good detection performances in human serum medium and for screening of  inhibitors.

miR-30a inhibits androgen-independent growth of prostate cancer via targeting MYBL2, FOXD1, and SOX4.

BACKGROUND: Castrate-resistant prostate cancer (CRPC) is an aggressive and lethal disease. The pathogenesis of CRPC is not fully understood and novel therapeutic targets need to be identified to improve the patients' prognosis. MicroRNA-30a (miR-30a) has been demonstrated to be a tumor suppressor in many types of solid malignancies. However, its role in androgen-independent (AI) growth of prostate cancer (PCa) received limited attention as yet. METHODS: The clinical association of miR-30a and its potential targets with AI growth was characterized by bioinformatics analyses. Regulation of cell proliferation and colony formation rates by miR-30a were tested using PCa cell models. Xenograft models were used to measure the regulation of prostate tumor growth by miR-30a. The real-time quantitative polymerase chain reaction was used to validate whether miR-30a and its targets regulate cell cycle control genes and androgen receptor (AR)-dependent transcription. Bioinformatics tools, Western blot, and luciferase reporter assays were utilized to identify miR-30a targets. RESULTS: Bioinformatic analysis showed that low expression of miR-30a is associated with castration resistance of PCa patients and poor outcomes. Transfection of miR-30a mimics inhibited the AI growth of PCa cells in vitro and in vivo. Upregulation of miR-30a in 22RV1 cells altered the expression of cell cycle control genes and AR-mediated transcription, while downregulation of miR-30a in LNCaP cells had the opposite effects to AR-mediated transcription. MYBL2, FOXD1, and SOX4 were identified as miR-30a targets. Downregulation of MYBL2, FOXD1, and SOX4 affected the expression of cell cycle control genes and AR-mediated transcription and suppressed the AI growth of 22RV1 cells. CONCLUSIONS: Our results suggest that miR-30a inhibits AI growth of PCa by targeting MYBL2, FOXD1, and SOX4. They provide novel insights into developing new treatment strategies for CRPC.

Ultrasensitive detection of butyrylcholinesterase activity based on the inner filter effect of MnO2 nanosheets on sulfur nanodots.

Butyrylcholinesterase (BChE) activity is an important index for a variety of diseases. In this work, a "turn-on" assay is proposed based on controlling the inner filter effect (IFE) of MnO2 nanosheets (NSs) on sulfur nanodots (S-dots). The fluorescence of S-dots is effectively quenched by the MnO2 NSs, due to the wide overlap of the emission spectrum of S-dots and absorption spectrum of MnO2 NSs, together with the superior light absorption capability of MnO2 NSs. BChE can catalyze acetylthiocholine and produce thiocholine, which effectively decomposes the MnO2 NSs into Mn2+, resulting in the disappearance of the IFE and recovery of fluorescence of S-dots. Two-stage linear relationships between the ratio of fluorescence intensity and concentration of BChE are observed from 0.05 to 10 and from 10 to 500 U L-1. A limit of detection of 0.035 U L-1 is achieved, which is the best performance so far. The as-proposed assay is robust enough for practical detection in human serum, and it can avoid interference from its sister enzyme (acetylcholinesterase) and glutathione at the micromolar level. The presented results provide a clue for the functionalization of S-dots, and offer a powerful tool as an analytic technique for nanomedicine and environmental science.

23,24-Dihydrocucurbitacin B promotes lipid clearance by dual transcriptional regulation of LDLR and PCSK9.

23,24-Dihydrocucurbitacin B (designated as C95 in this article) is a cucurbitane triterpenoid that has been shown to possess a variety of pharmacological activities, such as anti-inflammatory and anti-HIV-1 activities etc. In this study, we investigated the effects of 23,24-dihydrocucurbitacin B on lipid regulation. We showed that 23,24-dihydrocucurbitacin B (1-5 µM) dose-dependently promoted DiI-LDL uptake in HepG2 cells by upregulating low-density lipoprotein receptor (LDLR) protein. In HepG2 cells, 23,24-dihydrocucurbitacin B (1-10 µM) dose-dependently enhanced LDLR promoter activity by elevating the mature form of SREBP2 (sterol regulatory element binding protein 2) protein levels on one hand, and inhibited PCSK9 (proprotein convertase subtilisin/kexin type 9) promoter activity by attenuating HNF1α (hepatocyte nuclear factor-1α) protein levels in nuclei on the other hand. Consequently, the expression of LDLR protein markedly increased, whereas the PCSK9-mediated LDLR protein degradation decreased. In a high-cholesterol LVG golden Syrian Hamster model, administration of 23,24-dihydrocucurbitacin B (30 mg · kg-1⋅ d-1, intragastric, for 3 weeks) significantly decreased the serum LDL-cholesterol (LDL-C) levels. PCSK9 protein levels in the serum and liver tissues were significantly decreased, whereas LDLR protein levels in liver tissues were significantly increased in the treated animals as compared with the control animals. In conclusion, our study demonstrates for the first time that 23,24-dihydrocucurbitacin B exhibits dual transcriptional regulation of LDLR and PCSK9 in HepG2 cells by increasing SREBP2 protein levels and decreasing HNF1α protein levels in the nuclei. These results propose a new strategy to simultaneously manage LDLR and PCSK9 protein expression and provide a promising lead compound for drug development.

CUL4B/miR-33b/C-MYC axis promotes prostate cancer progression.

BACKGROUND: Cullin 4B (CUL4B), a scaffold protein that assembles CRL4B ubiquitin ligase complexes, is overexpressed in many types of solid tumors and contributes to epigenetic silencing of tumor suppressors. However, its clinical significance and underlying molecular mechanisms in prostate cancer (PCa) remain unknown. METHODS: The clinical significance of CUL4B in PCa was characterized by in silico method. RT-qPCR and Western blot were used to study the transcript and protein expression levels of CUL4B and C-MYC. Bioinformatics tools, chromatin immunoprecipitation (ChIP) and luciferase reporter assay were utilized to identify and characterize the microRNAs (miRNAs) regulated by CUL4B. The biological function of CUL4B and miR-33b-5p was evaluated by MTS, transwell, and wound healing assays, accordingly. RESULTS: CUL4B is significantly overexpressed in PCa tissues compared with benign prostatic tissues and its overexpression is correlated with poor prognosis. CUL4B promotes proliferation and aggressiveness of PCa cells in vitro. Mechanistically, we demonstrate that CUL4B upregulates the expression of C-MYC at post-transcriptional level through epigenetic silencing of miR-33b-5p. Importantly, CUL4B-induced oncogenic activity in PCa by targeting C-MYC is repressed by miR-33b-5p. CONCLUSIONS: Our results suggested a novel CUL4B/miR-33b/C-MYC axis implicated in PCa cell growth and progression. This might provide novel insight into how CUL4B contributed to PCa aggressiveness and progression.

CUL4B regulates cancer stem-like traits of prostate cancer cells by targeting BMI1 via miR200b/c.

BACKGROUND: Cancer stem-like traits contribute to prostate cancer (PCa) progression and metastasis. Cullin 4B (CUL4B) is a member of the ubiquitin E3 ligase family and overexpressed in several solid malignancies including PCa. CUL4B has been suggested to be an oncogene through epigenetic repression of tumor suppressors. However, the link between CUL4B expression and cancer stem-like phenotype remains unclear. METHODS: Western blot analysis, sphere formation, and colony formation assays were used to examine the effect of CUL4B on cancer stem-like traits in PCa cells. Mechanically, bioinformatic analysis was utilized to evaluate whether BMI1 was a target of CUL4B. Moreover, real-time polymerase chain reaction, chromatin immunoprecipitation, and luciferase reporter assays were performed to identify microRNAs regulated by CUL4B. Finally, Western blot assay was used to validate the regulation of CUL4B, miR200b, and miR200c (miR200b/c) on the stem-like characteristics of PCa cells. RESULTS: CUL4B promotes PCa pluripotency-associated markers expression, sphere formation, and anchorage-independent growth ability in vitro. Mechanically, CUL4B upregulates BMI1 expression via epigenetically repressing miR200b/c expression. In addition, miR200b/c could partially reverse CUL4B-induced BMI1 and pluripotency-associated marker expression. CONCLUSIONS: Our study revealed that CUL4B regulates cancer stem-like traits of prostate cancer cells by targeting BMI1 via miR200b/c, which might give novel insight into how CUL4B promotes PCa progression through regulating cancer stem-like traits.

Enhancer of zeste 2 polycomb repressive complex 2 subunit promotes sorafenib resistance of hepatocellular carcinoma though insulin-like growth factor 1 receptor.

Enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) is the core component of polycomb repressive complex 2 and is overexpressed in several types of solid malignancies. It has been reported that EZH2 contributes to sorafenib resistance of hepatocellular carcinoma (HCC). However, its underlying molecular mechanisms remain unknown. In this study, we demonstrated that EZH2 induced sorafenib resistance of HCC cells in vitro. Mechanistically, EZH2 was a potent regulator of insulin-like growth factor 1 receptor (IGF1R) and EZH2-modulated IGF1R expression by directly transcriptionally repressing a set of microRNAs (miRNAs) including miR-101, miR-122, miR-125b, and miR-139. These miRNAs were required for EZH2-mediated sorafenib resistance by promoting IGF1R expression. Surprisingly, IGF1R inhibitors significantly reversed EZH2-induced sorafenib resistance. Collectively, we proposed a novel model for an EZH2 - miRNAs - IGF1R regulatory axis, which might provide insights into how EZH2 contributes to sorafenib resistance in HCC.