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Gene expression patterns are very sensitive to external influences and are reflected in phenotypic changes. It was previously described that transferring melanoma cells from a plastic surface to Matrigel led to formation of de novo vascular networks-vasculogenic mimicry-that are characteristic to a stemness phenotype in aggressive tumors. Up to now there was no detailed data about the gene signature accompanying this process. Here, we show that this transfer shortly led to extremely strong epigenetic changes in gene expression in the melanoma cells. We observed that on Matrigel numerous genes controlling ribosome biogenesis were upregulated. However, most of the activated genes were inhibitors of the differentiation genes ( ID1 , ID2 , and ID3 ). At the same time, the genes that control differentiation were downregulated. Both the upregulated and the downregulated genes are simultaneously targeted by different transcription factors shaping sets of co-expressed genes. The specific group of downregulated genes shaping contacts with rDNA genes are also associated with the H3K27me3 mark and with numerous lincRNAs and miRNAs. We conclude that the stemness phenotype of melanoma cells is due to the downregulation of developmental genes and formation of dedifferentiated cells.

Background: The mechanisms enabling dynamic shifts between drug-resistant and drug-sensitive states in cancer cells are still underexplored. This study investigated the role of targeted autophagic protein degradation in regulating ovarian cancer stem cell (CSC) fate decisions and chemo-resistance., Methods: Autophagy levels were compared between CSC-enriched side population (SP) and non-SP cells (NSP) in multiple ovarian cancer cell lines using immunoblotting, immunofluorescence, and transmission electron microscopy. The impact of autophagy modulation on CSC markers and differentiation was assessed by flow cytometry, immunoblotting and qRT-PCR. In silico modeling and co-immunoprecipitation identified ID1 interacting proteins. Pharmacological and genetic approaches along with Annexin-PI assay, ChIP assay, western blotting, qRT-PCR and ICP-MS were used to evaluate effects on cisplatin sensitivity, apoptosis, SLC31A1 expression, promoter binding, and intracellular platinum accumulation in ID1 depleted backdrop. Patient-derived tumor spheroids were analyzed for autophagy and SLC31A1 levels., Results: Ovarian CSCs exhibited increased basal autophagy compared to non-CSCs. Further autophagy stimulation by serum-starvation and chemical modes triggered proteolysis of the stemness regulator ID1, driving the differentiation of chemo-resistant CSCs into chemo-sensitive non-CSCs. In silico modeling predicted TCF12 as a potent ID1 interactor, which was validated by co-immunoprecipitation. ID1 depletion freed TCF12 to transactivate the cisplatin influx transporter SLC31A1, increasing intracellular cisplatin levels and cytotoxicity. Patient-derived tumor spheroids exhibited a functional association between autophagy, ID1, SLC31A1, and platinum sensitivity., Conclusions: This study reveals a novel autophagy-ID1-TCF12-SLC31A1 axis where targeted autophagic degradation of ID1 enables rapid remodeling of CSCs to reverse chemo-resistance. Modulating this pathway could counter drug resistance in ovarian cancer., (© 2024. The Author(s).)

Purpose: Kinase interacting with stathmin (KIS) is a serine/threonine kinase involved in RNA processing and protein phosphorylation. Increasing evidence has suggested its involvement in cancer progression. The aim of this study was to investigate the role of KIS in the development of lung adenocarcinoma (LUAD). Dual luciferase assay was used to explore the relationship between KIS and SOX4, and its effect on ID1/β-catenin pathway., Methods: Real-time qPCR and western blot were used to assess the levels of KIS and other factors. Cell proliferation, migration, and invasion were monitored, and xenograft animal model were established to investigate the biological functions of KIS in vitro and in vivo., Results: In the present study, KIS was found to be highly expressed in LUAD tissues and cell lines. KIS accelerated the proliferative, migratory and invasive abilities of LUAD cells in vitro, and promoted the growth of LUAD in a mouse tumor xenograft model in vivo. Mechanistically, KIS activated the β-catenin signaling pathway by modulating the inhibitor of DNA binding 1 (ID1) and was transcriptionally regulated by SOX4 in LUAD cells., Conclusion: KIS, a target of SOX4, regulates the ID1-mediated enhancement of β-catenin to facilitate LUAD cell invasion and metastasis., (© 2024. The Author(s).)

Background: Colorectal cancer (CRC) is the second most deathly worldwide and third most common cancer, CRC is a very heterogeneous disease where tumors can form by both environmental and genetic risk factors and includes epigenetic and genetic alternations. Inhibitors of DNA binding proteins (ID) are a class of helix-loop-helix transcription regulatory factors; these proteins are considered a family of four highly preserved transcriptional regulators (ID1-4), shown to play significant roles in many processes that are associated with tumor development. ID family plays as negatively dominant antagonists of other essential HLH proteins, concluding the creation of non-functional heterodimers and regulation of the transcription process., Materials and Methods: 120 Fresh tissue and blood samples Forty (40) samples of fresh tissue and blood were collected from patients diagnosed with CRC, twenty (20) samples were collected from a patient diagnosed as healthy. The (qRT-PCR) method is a sensitive technique for the quantifying of steady-state mRNA levels that used to evaluation the expression levels of ID (1-4) gene., Results: The findings indicate downregulation in ID1 in tissue with a highly significant change between patients and control groups, where upregulation in the ID1 gene is shown in blood samples.ID2 gene also demonstrated high significant change where show upregulation in tissue and downregulation in blood sample. ID3 and ID4 genes show downregulation in tissue and blood samples with a significant change in ID3 blood samples between patient and blood groups., Conclusion: Because of the regulation function of the ID family in many processes, the up or down regulation of IDs genes in tumors Proves how important its tumor development, and therefore those proteins can be used as an indicator for CRC., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Although the roles of E proteins and inhibitors of DNA-binding (Id) in T follicular helper (TFH) and T follicular regulatory (TFR) cells have been previously reported, direct models demonstrating the impact of multiple E protein members have been lacking. To suppress all E proteins including E2A, HEB and E2-2, we overexpressed Id1 in CD4 cells using a CD4-Id1 mouse model, to observe any changes in TFH and TFR cell differentiation. Our objective was to gain better understanding of the roles that E proteins and Id molecules play in the differentiation of TFH and TFR cells. The CD4-Id1 transgenic (TG) mice that we constructed overexpressed Id1 in CD4 cells, inhibiting E protein function. Our results showed an increase in the proportion and absolute numbers of Treg, TFH and TFR cells in the spleen of TG mice. Additionally, the expression of surface characterisation molecules PD-1 and ICOS was significantly upregulated in TFH and TFR cells. The study also revealed a downregulation of the marginal zone B cell precursor and an increase in the activation and secretion of IgG1 in spleen B cells. Furthermore, the peripheral TFH cells of TG mice enhanced the function of assisting B cells. RNA sequencing results indicated that a variety of TFH-related functional molecules were upregulated in TFH cells of Id1 TG mice. In conclusion, E proteins play a crucial role in regulating TFH/TFR cell differentiation and function and suppressing E protein activity promotes germinal centre humoral immunity, which has important implications for immune regulation and treating related diseases., (© 2024 John Wiley & Sons Ltd.)

Although bevacizumab (BVZ), a representative drug for anti-angiogenesis therapy (AAT), is used as a first-line treatment for patients with glioblastoma (GBM), its efficacy is notably limited. Whereas several mechanisms have been proposed to explain the acquisition of AAT resistance, the specific underlying mechanisms have yet to be sufficiently ascertained. Here, we established that inhibitor of differentiation 1 (ID1) high /activin A high glioblastoma cell confers resistance to BVZ. The bipotent effect of activin A during its active phase was demonstrated to reduce vasculature dependence in tumorigenesis. In response to a temporary exposure to activin A, this cytokine was found to induce endothelial-to-mesenchymal transition via the Smad3/Slug axis, whereas prolonged exposure led to endothelial apoptosis. ID1 tumors showing resistance to BVZ were established to be characterized by a hypovascular structure, hyperpermeability, and scattered hypoxic regions. Using a GBM mouse model, we demonstrated that AAT resistance can be overcome by administering therapy based on a combination of BVZ and SB431542, a Smad2/3 inhibitor, which contributed to enhancing survival. These findings offer valuable insights that could contribute to the development of new strategies for treating AAT-resistant GBM., (© 2024. The Author(s).)

Sorafenib resistance greatly restricts its clinical application in patients with hepatocellular carcinoma (HCC). Numerous studies have reported that ID1 exerts a crucial effect in cancer initiation and development. Our previous research revealed an inhibitory role of ID1 in sorafenib resistance. However, the upstream regulatory mechanism of ID1 expression is unclear. Here, we discovered that ID1 expression is negatively correlated with promoter methylation, which is regulated by DNMT3B. Knockdown of DNMT3B significantly inhibited ID1 methylation status and resulted in an increase of ID1 expression. The demethylating agent 5-aza-2'-deoxycytidine (5-aza) remarkably upregulated ID1 expression. The combination of 5-aza with sorafenib showed a synergistic effect on the inhibition of cell viability., (© 2023 The Authors. FEBS Open Bio published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Elimination of cancer stem cells (CSCs) and reinvigoration of antitumor immunity remain unmet challenges for cancer therapy. Tumor-associated macrophages (TAMs) constitute the prominant population of immune cells in tumor tissues, contributing to the formation of CSC niches and a suppressive immune microenvironment. Here, we report that high expression of inhibitor of differentiation 1 (ID1) in TAMs correlates with poor outcome in patients with colorectal cancer (CRC). ID1 expressing macrophages maintain cancer stemness and impede CD8 + T cell infiltration. Mechanistically, ID1 interacts with STAT1 to induce its cytoplasmic distribution and inhibits STAT1-mediated SerpinB2 and CCL4 transcription, two secretory factors responsible for cancer stemness inhibition and CD8 + T cell recruitment. Reducing ID1 expression ameliorates CRC progression and enhances tumor sensitivity to immunotherapy and chemotherapy. Collectively, our study highlights the pivotal role of ID1 in controlling the protumor phenotype of TAMs and paves the way for therapeutic targeting of ID1 in CRC., (© 2023. The Author(s).)

Background: Few effective anti-fibrotic therapies are currently available for liver cirrhosis. Mesenchymal stromal cells (MSCs) ameliorate liver fibrosis and contribute to liver regeneration after cirrhosis, attracting much attention as a potential therapeutic strategy for the disease. However, the underlying molecular mechanism of their therapeutic effect is still unclear. Here, we investigated the effect of human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs) in treating liver cirrhosis and their underlying mechanisms., Methods: We used carbon tetrachloride (CCl 4 )-induced mice as liver cirrhosis models and treated them with hUC-MSCs via tail vein injection. We assessed the changes in liver function, inflammation, and fibrosis by histopathology and serum biochemistry and explored the mechanism of hUC-MSCs by RNA sequencing (RNA-seq) using liver tissues. In addition, we investigated the effects of hUC-MSCs on hepatic stellate cells (HSC) and macrophages by in vitro co-culture experiments., Results: We found that hUC-MSCs considerably improved liver function and attenuated liver inflammation and fibrosis in CCl 4 -injured mice. We also showed that these cells exerted therapeutic effects by regulating the Hippo/YAP/Id1 axis in vivo. Our in vitro experiments demonstrated that hUC-MSCs inhibit HSC activation by regulating the Hippo/YAP signaling pathway and targeting Id1. Moreover, hUC-MSCs also alleviated liver inflammation by promoting the transformation of macrophages to an anti-inflammatory phenotype., Conclusions: Our study reveals that hUC-MSCs relieve liver cirrhosis in mice through the Hippo/YAP/Id1 pathway and macrophage-dependent mechanisms, providing a theoretical basis for the future use of these cells as a potential therapeutic strategy for patients with liver cirrhosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

The bone marrow microenvironment (BMM) can regulate leukemia stem cells (LSCs) via secreted factors. Increasing evidence suggests that dissecting the mechanisms by which the BMM maintains LSCs may lead to the development of effective therapies for the eradication of leukemia. Inhibitor of DNA binding 1 (ID1), a key transcriptional regulator in LSCs, previously identified by us, controls cytokine production in the BMM, but the role of ID1 in acute myeloid leukemia (AML) BMM remains obscure. Here, we report that ID1 is highly expressed in the BMM of patients with AML, especially in BM mesenchymal stem cells, and that the high expression of ID1 in the AML BMM is induced by BMP6, secreted from AML cells. Knocking out ID1 in mesenchymal cells significantly suppresses the proliferation of cocultured AML cells. Loss of Id1 in the BMM results in impaired AML progression in AML mouse models. Mechanistically, we found that Id1 deficiency significantly reduces SP1 protein levels in mesenchymal cells cocultured with AML cells. Using ID1-interactome analysis, we found that ID1 interacts with RNF4, an E3 ubiquitin ligase, and causes a decrease in SP1 ubiquitination. Disrupting the ID1-RNF4 interaction via truncation in mesenchymal cells significantly reduces SP1 protein levels and delays AML cell proliferation. We identify that the target of Sp1, Angptl7, is the primary differentially expression protein factor in Id1-deficient BM supernatant fluid to regulate AML progression in mice. Our study highlights the critical role of ID1 in the AML BMM and aids the development of therapeutic strategies for AML., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Metastasis is a significant cause of high mortality in lung cancer. Lymph node (LN) metastasis is the most common metastatic pathway in non-small cell lung cancer and the most crucial factor affecting the prognosis of NSCLC. Nevertheless, the molecular mechanism underlying metastasis is unknown. We demonstrated that higher NADK expression suggests worsened survival prognosis, and NADK expression positively correlates with the lymph node metastasis rate and TNM and AJCC stages in NSCLC patients. Moreover, patients with LN metastasis show higher NADK expression than those without LN metastasis. NADK can promote NSCLC progression by enhancing the migration, invasion, lymph node metastasis and growth of NSCLC cells. Mechanistically, NADK inhibits the ubiquitination and degradation of BMPR1A by interacting with Smurf1, further activating the BMPs signalling pathway and promoting ID1 transcription. In conclusion, NADK may be a potential diagnostic indicator and a novel therapeutic target for metastatic NSCLC., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Background: High expression of inhibitor of DNA binding 1 ( ID1 ) correlates with poor prognosis in colorectal cancer (CRC). Aberrant enhancer activation in regulating ID1 transcription is limited., Methods: Immunohistochemistry (IHC), quantitative RT-PCR (RT-qPCR) and Western blotting (WB) were used to determine the expression of ID1 . CRISPR-Cas9 was used to generate ID1 or enhancer E1 knockout cell lines. Dual-luciferase reporter assay, chromosome conformation capture assay and ChIP-qPCR were used to determine the active enhancers of ID1 . Cell Counting Kit 8, colony-forming, transwell assays and tumorigenicity in nude mice were used to investigate the biological functions of ID1 and enhancer E1., Results: Human CRC tissues and cell lines expressed a higher level of ID1 than normal controls. ID1 promoted CRC cell proliferation and colony formation. Enhancer E1 actively regulated ID1 promoter activity. Signal transducer and activator of transcription 3 (STAT3) bound to ID1 promoter and enhancer E1 to regulate their activity. The inhibitor of STAT3 Stattic attenuated ID1 promoter and enhancer E1 activity and the expression of ID1 . Enhancer E1 knockout down-regulated ID1 expression level and cell proliferation in vitro and in vivo., Conclusions: Enhancer E1 is positively regulated by STAT3 and contributes to the regulation of ID1 to promote CRC cell progression and might be a potential target for anti-CRC drug studies., Competing Interests: The authors declare no conflicts of interest.

Photodynamic therapy (PDT) is an effective and low‑invasive tumour therapy. However, it can induce tumour angiogenesis, which is a main factor leading to tumour recurrence and metastasis. Activin receptor‑like kinase‑1 (ALK1) is a key factor regulating angiogenesis. However, it remains unclear whether ALK1 plays an unusual role in low‑dose PDT‑induced tumour angiogenesis. In the present study, human umbilical vein endothelial cells (HUVECs) co‑cultured with breast cancer MDA‑MB‑231 cells (termed HU‑231 cells) were used to construct an experimental model of tumour angiogenesis induced by low‑dose PDT. The viability, and the proliferative, invasive, migratory, as well as the tube‑forming ability of the HU‑231 cells were evaluated following low‑dose PDT. In particular, ALK1 inhibitor and and an adenovirus against ALK1 were used to further verify the role of ALK1 in low‑dose PDT‑induced tumour angiogenesis. Moreover, the expression of ALK1, inhibitor of DNA binding 1 (ID1), Smad 1, p‑Smad1/5, AKT and PI3K were detected in order to verify the underlying mechanisms. The findings indicated that low‑dose PDT enhanced the proliferative ability of the HU‑231 cells and reinforced their migratory, invasive and tube formation capacity. However, these effects were reversed with the addition of an ALK1 inhibitor or by the knockdown of ALK1 using adenovirus. These results indicated that ALK1 was involved and played a critical role in tumour angiogenesis induced by low‑dose PDT. Furthermore, ALK1 was found to participate in PDT‑induced tumour angiogenesis by activating the Smad1/5‑ID1 pathway, as opposed to the PI3K/AKT pathway. On the whole, the present study, for the first time, to the best of our knowledge, demonstrates that ALK1 is involved in PDT‑induced tumour angiogenesis. The inhibition of ALK1 can suppress PDT‑induced tumour angiogenesis, which can enhance the effects of PDT and may thus provide a novel treatment strategy for PDT.

RSL3 is a synthetic molecule that inactivates glutathione peroxidase 4 to induce ferroptosis. However, its effect on glioma stem cells (GSC) remains unclear. In this study, we found that RSL3 significantly suppressed GSC proliferation and induced their differentiation into astrocytes, which was accompanied by the downregulation of stemness-related markers, including Nestin and Sox2. Combined transcriptome and proteome analyses further revealed that RSL3 promoted GSC differentiation by suppressing transglutaminase 2 (Tgm2), but not by ferroptosis-related pathways. Tgm2 overexpression in CSC2078 cells rescued the changes in stemness-related markers and differentiation caused by RSL3, which was mediated by inhibitor of DNA binding 1 (ID1) activation. Further studies identified ID1 as a downstream signaling target of Tgm2. Blocking the phosphoinositide-3 kinase (PI3K)/Akt pathway with LY294002 suppressed PI3K, p-Akt, and ID1 levels but not Tgm2. Tgm2 overexpression abrogated the changes in PI3K, p-Akt, and ID1 levels caused by LY294002. Taken together, we demonstrate that RSL3 does not induce ferroptosis; instead, it inhibits GSC proliferation and triggers their differentiation by suppressing the Tgm2/Akt/ID1 signaling axis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The regulatory circuits that coordinate epidermal differentiation during development are still not fully understood. Here, we report that the transcriptional regulator ID1 is enriched in mouse basal epidermal progenitor cells and find ID1 expression to be diminished upon differentiation. In utero silencing of Id1 impairs progenitor cell proliferation, leads to precocious delamination of targeted progenitor cells and enables differentiated keratinocytes to retain progenitor markers and characteristics. Transcriptional profiling suggests that ID1 acts by mediating adhesion to the basement membrane while inhibiting spinous layer differentiation. Co-immunoprecipitation reveals ID1 binding to transcriptional regulators of the class I bHLH family. We localize bHLH Tcf3, Tcf4 and Tcf12 to epidermal progenitor cells during epidermal stratification and establish TCF3 as a downstream effector of ID1-mediated epidermal proliferation. Finally, we identify crosstalk between CEBPA, a known mediator of epidermal differentiation, and Id1, and demonstrate that CEBPA antagonizes BMP-induced activation of Id1. Our work establishes ID1 as a key coordinator of epidermal development, acting to balance progenitor proliferation with differentiation and unveils how functional crosstalk between CEBPA and Id1 orchestrates epidermal lineage progression., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)

ID1 is a labile protein implicated in the development and progression of several malignant tumors, but the mechanisms regulating ID1 stability and function in human esophageal squamous cell carcinoma (ESCC) are largely unclear. In this study, we performed an immunoprecipitation assay to screen for deubiquitinases that may interact with ID1 and identified USP8 as a novel deubiquitinase for ID1. USP8 interacts with ID1, and increases the protein level and stability of ID1 by reducing its ubiquitination. Ectopic expression of USP8 promotes ESCC tumorigenesis by suppressing ID1 degradation, whereas knockdown of USP8 results in the opposite phenotypes in vitro and in vivo. Moreover, we found that TXNIP is a novel downstream target of ID1, and USP8 promotes ESCC tumorigenesis by activating the ID1-TXNIP pathway. Increased expression of USP8 and ID1 positively correlates with reduced TXNIP expression in ESCC tissues and predicts an advanced tumor stage. Overall, our data indicate that USP8 is a novel deubiquitinase for ID1 and show the importance of the USP8-ID1-TXNIP axis in promoting ESCC tumorigenesis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Pancreatic Ductal Adenocarcinoma (PDAC) is a deadly disease that has an increasing death rate but no effective treatment to now. Although biological and immunological hallmarks of PDAC have been frequently reported recently, early detection and the particularly aggressive biological features are the major challenges remaining unclear. In the current study, we retrieved multiple scRNA-seq datasets and illustrated the genetic programs of PDAC development in genetically modified mouse models. Notably, the transcription levels of Id1 were elevated specifically along with the PDAC development. Pseudotime trajectory analysis revealed that Id1 was closely correlated with the malignancy of PDAC. The gene expression patterns of human PDAC cells were determined by the comparative analysis of the scRNA-seq data on human PDAC and normal pancreas tissues. ID1 levels in human PDAC cancer cells were dramatically increased compared to normal epithelial cells. ID1 deficiency in vitro significantly blunt the invasive tumor-formation related phenotypes. IPA analysis on the differentially expressed genes suggested that EIF2 signaling was the core pathway regulating the development of PDAC. Blocking EFI2 signaling remarkably decreased the expression of ID1 and attenuated the tumor-formation related phenotypes. These observations confirmed that ID1 was regulated by EIF2 signaling and was the critical determinator of PDAC development and progression. This study suggests that ID1 is a potential malignant biomarker of PDAC in both mouse models and human and detecting and targeting ID1 may be a promising strategy to treat or even rescue PDAC., (© 2022. The Author(s).)

Acute myeloid leukemia (AML) is characterized by the dysregulation of hematopoietic cell proliferation, resulting in the accumulation of immature myeloid cells in bone marrow. 5-Demethylnobiletin (5-demethyl NOB), a citrus 5-hydroxylated polymethoxyflavone, has been reported to exhibit various bioactivities, such as antioxidant, anti-inflammatory and anticancer properties. In this study, we investigated the antileukemic effects of 5-demethyl NOB and its underlying molecular mechanisms in human AML cells. We found that 5-demethyl NOB (20−80 μM) significantly reduced human leukemia cell viability, and the following trend of effectiveness was observed: THP-1 ≈ U-937 > HEL > HL-60 > K562 cells. 5-Demethyl NOB (20 and 40 μM) modulated the cell cycle through the regulation of p21, cyclin E1 and cyclin A1 expression and induced S phase arrest. 5-Demethyl NOB also promoted leukemia cell apoptosis and differentiation. Microarray-based transcriptome, Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) of differentially expressed genes (DEGs) analysis showed that the expression of inhibitor of differentiation/DNA binding 1 (ID1), a gene associated with the GO biological process (BP) cell population proliferation (GO: 0008283), was most strongly suppressed by 5-demethyl NOB (40 μM) in THP-1 cells. We further demonstrated that 5-demethyl NOB-induced ID1 reduction was associated with the inhibition of leukemia cell growth. Moreover, DEGs involved in the hallmark gene set NF-κB/TNF-α signaling pathway were markedly enriched and downregulated by 5-demethyl NOB. Finally, we demonstrated that 5-demethyl NOB (20 and 40 μM), combined with cytarabine, synergistically reduced THP-1 and U-937 cell viability. Our current findings support that 5-demethyl NOB dramatically suppresses leukemia cell proliferation and may serve as a potential phytochemical for human AML chemotherapy.

Long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) exerts a pro-oncogenic role in several cancers, whereas its underlying regulatory mechanism in papillary thyroid carcinoma (PTC) progression remains unknown. This research mainly explored the roles of NEAT1 in PTC development. Quantitative real-time polymerase-chain reaction (qRT-PCR) was applied to measure NEAT1, miR-524-5p, and inhibitor of DNA binding 1 (ID1) expression in PTC tissues and cells. Western blot was conducted for detecting the protein levels. MTT, transwell, and flow cytometry assays were applied to assess cell proliferation, metastasis, and apoptosis in PTC cells in vitro . The PTC xenograft tumor model was used for investigating the role of NEAT1 in vivo . Dual-luciferase reporter assay was utilized for confirming the interaction between miR-524-5p and NEAT1 or ID1. In PTC tissues and cells, NEAT1 was significantly up-regulated. NEAT1 silencing blocked cell proliferation, metastasis, and facilitated apoptosis in vitro and impeded xenograft tumor growth in vivo . Bioinformatics prediction revealed the existence of binding sites between NEAT1 and miR-524-5p. Besides, ID1 was confirmed as a direct target to miR-524-5p, and the enhancement of ID1 reversed the regulation of miR-524-5p upregulation on cell progression. In addition, NEAT1 promoted PTC development by regulating ID1 expression via sponging miR-524-5p in PTC. In summary, we demonstrate that NEAT1 advanced the process of PTC by miR-524-5p/ID1 axis, which may enhance our comprehension of PTC pathogenesis.

E-protein transcription factors limit group 2 innate lymphoid cell (ILC2) development while promoting T cell differentiation from common lymphoid progenitors. Inhibitors of DNA binding (ID) proteins block E-protein DNA binding in common lymphoid progenitors to allow ILC2 development. However, whether E-proteins influence ILC2 function upon maturity and activation remains unclear. Mice that overexpress ID1 under control of the thymus-restricted proximal Lck promoter (ID1 tg/WT ) have a large pool of primarily thymus-derived ILC2s in the periphery that develop in the absence of E-protein activity. We used these mice to investigate how the absence of E-protein activity affects ILC2 function and the genomic landscape in response to house dust mite (HDM) allergens. ID1 tg/WT mice had increased KLRG1 - ILC2s in the lung compared with wild-type (WT; ID1 WT/WT ) mice in response to HDM, but ID1 tg/WT ILC2s had an impaired capacity to produce type 2 cytokines. Analysis of WT ILC2 accessible chromatin suggested that AP-1 and C/EBP transcription factors but not E-proteins were associated with ILC2 inflammatory gene programs. Instead, E-protein binding sites were enriched at functional genes in ILC2s during development that were later dynamically regulated in allergic lung inflammation, including genes that control ILC2 response to cytokines and interactions with T cells. Finally, ILC2s from ID1 tg/WT compared with WT mice had fewer regions of open chromatin near functional genes that were enriched for AP-1 factor binding sites following HDM treatment. These data show that E-proteins shape the chromatin landscape during ILC2 development to dictate the functional capacity of mature ILC2s during allergic inflammation in the lung., (Copyright © 2022 by The American Association of Immunologists, Inc.)

Since hepatocellular carcinoma (HCC) is a typical hypervascular malignant tumor with poor prognosis, targeting angiogenesis is an important therapeutic strategy for advanced HCC. Involvement of bone morphologic protein 9 (BMP9), a transforming growth factor-beta superfamily member, has recently been reported in the development of liver diseases and angiogenesis. Here, we aimed to elucidate the role of BMP9 signaling in promoting HCC angiogenesis and to assess the antiangiogenic effect of BMP receptor inhibitors in HCC. By analyzing HCC tissue gene expression profiles, we found that BMP9 expression was significantly correlated with angiogenesis-associated genes, including HIF-1α and VEGFR2. In vitro, BMP9 induced HCC cell HIF-1α/VEGFA expression and VEGFA secretion. Silencing of the inhibitor of DNA-binding protein 1 (ID1), a transcription factor targeted by BMP9 signaling, suppressed BMP9-induced HIF-1α/VEGFA expression and VEGFA secretion, resulting in decreased human umbilical vein endothelial cell (HUVEC) lumen formation. BMP receptor inhibitors, which inhibit BMP9-ID1 signaling, suppressed BMP9-induced HIF-1α/VEGFA expression, VEGFA secretion, and HUVEC lumen formation. In vivo, the BMP receptor inhibitor LDN-212854 successfully inhibited HCC tumor growth and angiogenesis by inhibiting BMP9-ID1 signaling. In summary, BMP9-ID1 signaling promotes HCC angiogenesis by activating HIF-1α/VEGFA expression. Thus, targeting BMP9-ID1 signaling could be a pivotal therapeutic option for advanced HCC.

Hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC), which required developing novel therapies targeting the inhibition of HBV transcription and replication due to current limited treatment options. We explored novel target for the development of novel therapies targeting the inhibition of HBV replication and transcription. The expression of Id1 and E2F4 in HCC cells and tissues was detected by qRT-PCR and western blot. We investigated the Id1 and E2F4-mediated transcription of HBV infection by using HepG2.2.15, HepAD38, HepG2-NTCP cell lines and AAV/HBV-infected mice. Interactions between the two host proteins and viral covalently closed circular DNA (cccDNA) were assessed using subcellular localization, protein-protein interaction, chromatin immunoprecipitation, and luciferase assays. Ectopic Id1 significantly reduced HBV transcription and replication in both HBV-expressing cells and AAV/HBV-infected mice. Id1 and E2F4 could form a heterodimer to prevent E2F4 from promoting HBV transcription and replication. E2F4 could directly bind to cccDNA and activate the HBV core promoter in cell lines. Furthermore, in vitro binding experiments confirmed that the sequence 1758'-TTAAAGGTC-1766', which is highly conserved among HBV genotypes, is the target site of the E2F4 homodimer. The findings suggest that E2F4 function as novel cccDNA-binding protein to directly activate HBV transcription by binding to Cp promoter region. Our results highlight the ability that E2F4 represent a pan-potential therapeutic target against HBV transcription and provide more clues to better understand the life cycle of HBV., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Foot-and-mouth disease virus (FMDV) is an important pathogen that harms cloven-hoofed animals and has caused serious losses to livestock production since its discovery. Furthermore, inhibitor of DNA binding (ID) proteins have been thoroughly studied in tumorigenesis, differentiation and metastasis, but its role in viral infection is rarely known. In this study, three gene knockout cell lines ID1 KO, ID3 KO, ID1/3 KO were obtained based on BHK-21 cells. We found that ID1 and ID3 genes single or double knockout promote the replication of FMDV. Moreover, compared with negative control cells during virus infection, there were 551 up-regulated genes and 1222 down-regulated genes in the ID1 KO cell line; 916 up-regulated genes and 1845 down-regulated genes in the ID3 KO cell line; 810 up-regulated genes and 1566 down-regulated genes in ID1/3 KO cell line. Further genes expression patterns verification results also showed a good correlation between the data of RT-qRCR and RNA-seq. These findings provide a basis for studying the relevant mechanisms between host genes and ID genes during FMDV infection., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Cutaneous wound healing requires intricate synchronization of several key processes. Among them, local nerve regeneration is known to be vitally important for proper repair. However, the underlying mechanisms of local nerve regeneration are still unclear. Fibroblasts are one of the key cell types within the skin whose role in local nerve regeneration has not been extensively studied. In our study, we found skin fibroblasts were in tight contact with regenerated nerves during wound healing, while rare interactions were shown under normal circumstances. Moreover, skin fibroblasts surrounding the nerves were shown to be activated and reprogrammed to exhibit neural cell-like properties by upregulated expressing inhibitor of DNA binding 1 (ID1) and ID3. Furthermore, we identified the regulation of integrin α6 (Itga6) by ID1/ID3 in fibroblasts as the mechanism for axon guidance. Accordingly, transplantation of the ID1/ID3-overexpressing fibroblasts or topical injection of ID1/ID3 lentivirus significantly promoted local nerve regeneration and wound healing following skin excision or sciatic nerve injury. Therefore, we demonstrated a new role for skin fibroblasts in nerve regeneration following local injury by directly contacting and guiding axon regrowth, which might hold therapeutic potential in peripheral nerve disorders and peripheral neuropathies in relatively chronic refractory wounds., (© 2021 The Authors. STEM CELLS TRANSLATIONAL MEDICINE published by Wiley Periodicals LLC on behalf of AlphaMed Press.)

Iron overload promotes the generation of reactive oxygen species (ROS). Pancreatic β-cells can counter oxidative stress through multiple anti-oxidant responses. Herein, RNA-sequencing was used to describe the expression profile of iron regulatory genes in human islets with or without diabetes. Functional experiments including siRNA silencing, qPCR, western blotting, cell viability, ELISA and RNA-sequencing were performed as means of identifying the genetic signature of the protective response following iron overload-induced stress in human islets and INS-1. FTH1 and FTL genes were highly expressed in human islets and INS-1 cells, while hepcidin (HAMP) was low. FXN, DMT1 and FTHL1 genes were differentially expressed in diabetic islets compared to control. Silencing of Hamp in INS-1 cells impaired insulin secretion and influenced the expression of β-cell key genes. RNA-sequencing analysis in iron overloaded INS-1 cells identified Id1 and Id3 as the top down-regulated genes, while Hmox1 was the top upregulated. Expression of ID1, ID3 and HMOX1 was validated at the protein level in INS-1 cells and human islets. Differentially expressed genes (DEGs) were enriched for TGF-β, regulating stem cells, ferroptosis, and HIF-1 signaling. Hmox1-silenced cells treated with FAC elevated the expression of Id1 and Id3 expression than untreated cells. Our findings suggest that HMOX1, ID1 and ID3 define the response mechanism against iron-overload-induced stress in β-cells., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Inhibitor of DNA binding (Id) is a dominant negative form of the E-box binding basic-helix-loop-helix (bHLH) transcription factor since it is devoid of the basic region required for DNA binding and forms an inactive hetero dimer with bHLH proteins. The E-box sequence located in the promoter region of the GATA-binding protein 4 (GATA-4) gene is essential for transcriptional activation in P19CL6 cells. These cells differentiate into cardiomyocytes and start to express GATA-4, which further triggers cardiac-specific gene expression. In this study, expression plasmids for Ids tagged with human influenza hemagglutinin (HA)-FLAG were constructed and introduced into P19CL6 cells. The stable clones expressing the recombinant Id proteins (Id1 or Id3) were isolated. The GATA-4 gene expression in these clones under differentiation condition in the presence of 1% dimethyl sulfoxide (DMSO) was repressed, with concomitant abolishment of the transcription of α-myosin heavy chain (α-MHC), which is a component of cardiac myofibrils. Thus, the increased expression of Id protein could affect GATA-4 gene expression and negatively regulate the differentiation of P19CL6 cells.

In melanoma, a phenotype switch from proliferation to invasion underpins metastasis, the major cause of melanoma-associated death. The transition from radial to vertical growth phase (invasive) melanoma is characterized by downregulation of both E-cadherin (CDH1) and MITF and upregulation of the key cancer-associated gene TBX3 and the phosphatidylinositol 3 kinase signaling pathway. Yet, whether and how these diverse events are linked remains poorly understood. Here, we show that TBX3 directly promotes expression of ID1, a dominant-negative regulator of basic helix-loop-helix transcription factors, and that ID1 decreases MITF binding and upregulation of CDH1. Significantly, we show that TBX3 activation of ID1 is necessary for TBX3 to enhance melanoma cell migration, and the mechanistic links between TBX3, ID1, MITF, and invasion revealed here are reflected in their expression in human melanomas. Our results reveal that melanoma migration is promoted through a TBX3-ID1-MITF-E-cadherin axis and that ID1-mediated repression of MITF activity may reinforce maintenance of an MITF Low phenotype associated with disease progression and therapy resistance., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Retinopathy of prematurity (ROP) remains one of the major causes of blindness in children worldwide. While current ROP treatments are mostly disruptive to reduce proliferative neovascularization by targeting the hypoxic phase, protection against early hyperoxia-induced retinal vascular loss represents an effective therapeutic window, but no such therapeutic strategy is available. Built upon our recent demonstration that the protection against oxygen-induced retinopathy by adenosine A 2A receptor (A 2A R) antagonists is most effective when administered at the hyperoxia (not hypoxic) phase, we here uncovered the cellular mechanism underlying the A 2A R-mediated protection against early hyperoxia-induced retinal vascular loss by reversing the inhibition of cellular proliferation via possibly multiple signaling pathways. Specifically, we revealed two distinct stages of the hyperoxia phase with greater cellular proliferation and apoptosis activities and upregulation of adenosine signaling at postnatal 9 day (P9) but reduced cellular activities and adenosine-A 2A R signaling at P12. Importantly, the A 2A R-mediated protection at P9 was associated with the reversal of hyperoxia-induced inhibition of progenitor cells at the peripheral retina at P9 and of retinal endothelial proliferation at P9 and P12. The critical role of cellular proliferation in the hyperoxia-induced retinal vascular loss was validated by the increased avascular areas by siRNA knockdown of the multiple signaling molecules involved in modulation of cellular proliferation, including activin receptor-like kinase 1, DNA-binding protein inhibitor 1, and vascular endothelial growth factor-A., (© 2021 Federation of American Societies for Experimental Biology.)

The malignant nature of hepatocellular carcinoma (HCC) is closely related to the presence of cancer stem cells (CSCs). Bone morphologic protein 9 (BMP9), a member of the transforming growth factor-beta (TGF-β) superfamily, was recently reported to be involved in liver diseases including cancer. We aimed to elucidate the role of BMP9 signaling in HCC-CSC properties and to assess the therapeutic effect of BMP receptor inhibitors in HCC. We have identified that high BMP9 expression in tumor tissues or serum from patients with HCC leads to poorer outcome. BMP9 promoted CSC properties in epithelial cell adhesion molecule (EpCAM)-positive HCC subtype via enhancing inhibitor of DNA-binding protein 1 (ID1) expression in vitro. Additionally, ID1 knockdown significantly repressed BMP9-promoted HCC-CSC properties by suppressing Wnt/β-catenin signaling. Interestingly, cells treated with BMP receptor inhibitors K02288 and LDN-212854 blocked HCC-CSC activation by inhibiting BMP9-ID1 signaling, in contrast to cells treated with the TGF-β receptor inhibitor galunisertib. Treatment with LDN-212854 suppressed HCC tumor growth by repressing ID1 and EpCAM in vivo. Our study demonstrates the pivotal role of BMP9-ID1 signaling in promoting HCC-CSC properties and the therapeutic potential of BMP receptor inhibitors in treating EpCAM-positive HCC. Therefore, targeting BMP9-ID1 signaling could offer novel therapeutic options for patients with malignant HCC., (© 2021 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

The aims of the present study were to examine the molecular mechanisms underlying sphingosine-1-phosphate (S1P)-induced rat pulmonary artery smooth muscle cells (PASMCs) proliferation/migration and to determine the effect of yes-associated protein (YAP) activation on S1P-induced PASMCs proliferation/migration and its potential mechanisms. S1P induced YAP dephosphorylation and nuclear translocation, upregulated microRNA-130a/b (miR-130a/b) expression, reduced bone morphogenetic protein receptor 2 (BMPR2), and inhibitor of DNA binding 1(Id1) expression, and promoted PASMCs proliferation and migration. Pretreatment of cells with Rho-associated protein kinase (ROCK) inhibitor Y27632 suppressed S1P-induced YAP activation, miR-130a/b upregulation, BMPR2/Id1 downregulation, and PASMCs proliferation/migration. Knockdown of YAP using small interfering RNA also suppressed S1P-induced alterations of miR-130a/b, BMPR2, Id1, and PASMCs behavior. In addition, luciferase reporter assay indicated that miR-130a/b directly regulated BMPR2 expression in PASMCs. Inhibition of miR-130a/b functions by anti-miRNA oligonucleotides attenuated S1P-induced BMPR2/Id1 downregulation and the proliferation and migration of PASMCs. Taken together, our study indicates that S1P induces activation of YAP through ROCK signaling and subsequently increases miR-130a/b expression, which, in turn, downregulates BMPR2 and Id1 leading to PASMCs proliferation and migration., (© 2020 Wiley Periodicals LLC.)

Background: ID1 is associated with resistance to the first generation of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). However, the effect of ID1 expression on osimertinib resistance in EGFR T790M-positive NSCLC is not clear., Methods: We established a drug-resistant cell line, H1975/OR, from the osimertinib-sensitive cell line H1975. Alterations in ID1 protein expression and Epithelial-mesenchymal transition (EMT)-related proteins were detected with western blot analysis. RT-PCR was used to evaluate the differences of gene mRNA levels. ID1 silencing and overexpression were used to investigate the effects of related gene on osimertinib resistance. Cell Counting Kit-8 (CCK8) was used to assess the proliferation rate in cells with altered of ID1 expression. Transwell assay was used to evaluate the invasion ability of different cells. The effects on the cell cycle and apoptosis were also compared using flow cytometry., Results: In our study, we found that in osimertinib-resistant NSCLC cells, the expression level of the EMT-related protein E-cadherin was lower than that of sensitive cells, while the expression level of ID1 and vimentin were higher than those of sensitive cells. ID1 expression levels was closely related to E-cadherin and vimentin in both osimertinib-sensitive and resistant cells. Alteration of ID1 expression in H1975/OR cells could change the expression of E-cadherin. Downregulating ID1 expression in H1975/OR cells could inhibit cell proliferation, reduce cell invasion, promote cell apoptosis and arrested the cell cycle in the G1/G0 stage phase. Our study suggests that ID1 may induce EMT in EGFR T790M-positive NSCLC, which mediates drug resistance of osimertinib., Conclusions: Our study revealed the mechanism of ID1 mediated resistance to osimertinib in EGFR T790M-positive NSCLC through EMT, which may provide new ideas and methods for the treatment of EGFR mutated NSCLC after osimertinib resistance.

The paradoxical roles of transforming growth factor-β (TGFβ) signaling and nuclear receptor Nur77 in colon cancer development are known but the underlying mechanisms remain obscure. Inhibitor of differentiation 1 (ID1) is a target gene of TGFβ and a key promoter for colon cancer progression. Here, we show that Nur77 enhances TGFβ/Smad3-induced ID1 mRNA expression through hindering Smurf2-mediated Smad3 mono-ubiquitylation, resulting in ID1 upregulation. In the absence of TGFβ, however, Nur77 destabilizes ID1 protein by promoting Smurf2-mediated ID1 poly-ubiquitylation, resulting in ID1 downregulation. Interestingly, TGFβ stabilizes ID1 protein by switching Nur77 interaction partners to inhibit ID1 ubiquitylation. This also endows TGFβ with an active pro-tumorigenic action in Smad4-deficient colon cancers. Thus, TGFβ converts Nur77's role from destabilizing ID1 protein and cancer inhibition to inducing ID1 mRNA expression and cancer promotion, which is highly relevant to colon cancer stemness, metastasis and oxaliplatin resistance. Our data therefore define the integrated duality of Nur77 and TGFβ signaling in regulating ID1 expression and provide mechanistic insights into the paradoxical roles of TGFβ and Nur77 in colon cancer progression.

As the clinical failure of glioblastoma treatment is attributed by multiple components, including myelin-associated infiltration, assessment of the molecular mechanisms underlying such process and identification of the infiltrating cells have been the primary objectives in glioblastoma research. Here, we adopted radiogenomic analysis to screen for functionally relevant genes that orchestrate the process of glioma cell infiltration through myelin and promote glioblastoma aggressiveness. The receptor of the Nogo ligand (NgR1) was selected as the top candidate through Differentially Expressed Genes (DEG) and Gene Ontology (GO) enrichment analysis. Gain and loss of function studies on NgR1 elucidated its underlying molecular importance in suppressing myelin-associated infiltration in vitro and in vivo. The migratory ability of glioblastoma cells on myelin is reversibly modulated by NgR1 during differentiation and dedifferentiation process through deubiquitinating activity of USP1, which inhibits the degradation of ID1 to downregulate NgR1 expression. Furthermore, pimozide, a well-known antipsychotic drug, upregulates NgR1 by post-translational targeting of USP1, which sensitizes glioma stem cells to myelin inhibition and suppresses myelin-associated infiltration in vivo. In primary human glioblastoma, downregulation of NgR1 expression is associated with highly infiltrative characteristics and poor survival. Together, our findings reveal that loss of NgR1 drives myelin-associated infiltration of glioblastoma and suggest that novel therapeutic strategies aimed at reactivating expression of NgR1 will improve the clinical outcome of glioblastoma patients., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Regorafenib is approved for patients with unresectable hepatocellular carcinoma (HCC) following sorafenib. However, the effect of regorafenib on HCC metastasis and its mechanism are poorly understood. Here, our data showed that regorafenib significantly restrained the migration, invasion and vasculogenic mimicry (VM) of HCC cells, and downregulated the expression of epithelial-to-mesenchymal transition (EMT)/VM-related molecules. Using RNA-seq and cellular thermal shift assays, we found that inhibitor of differentiation 1 (ID1) was a key target of regorafenib. In HCC tissues, the protein expression of ID1 was positively correlated with EMT and VM formation (CD34 - /PAS + ). Functionally, ID1 knockdown inhibited HCC cell migration, invasion, metastasis, and VM formation in vitro and in vivo, with upregulation of E-cadherin and downregulation of Snail and VE-cadherin. Moreover, Snail overexpression promoted the migration, invasion, and VM formation of ID1 knockdown cells. Snail knockdown reduced the migration, invasion, and VM formation of ID1 overexpression cells. Finally, regorafenib suppressed VM formation and decreased the expression of ID1, VE-cadherin and Snail in HCC PDX model. In conclusion, we manifested that regorafenib distinctly inhibited EMT in HCC cells via targeting ID1, leading to the suppression of cell migration, invasion and VM formation. These findings suggest that regorafenib may be developed as a suitable therapeutic agent for HCC metastasis., (© 2021 Wiley Periodicals LLC.)

Background: The human liver possesses a remarkable capacity for self-repair. However, liver fibrosis remains a serious medical concern, potentially progressing to end-stage liver cirrhosis and even death. Liver fibrosis is characterized by excess accumulation of extracellular matrix in response to chronic injury. Liver regenerative ability, a strong indicator of liver health, is important in resisting fibrosis. In this study, we provide evidence that ursodesoxycholic acid (UDCA) can alleviate liver fibrosis by promoting liver regeneration via activation of the ID1-WNT2/hepatocyte growth factor (HGF) pathway., Methods: Bile duct ligation (BDL) and partial hepatectomy (PH) mouse models were used to verify the effects of UDCA on liver fibrosis, regeneration, and the ID1-WNT2/HGF pathway. An Id1 knockdown mouse model was also used to assess the role of Id1 in UDCA alleviation of liver fibrosis., Results: Our results demonstrate that UDCA can alleviate liver fibrosis in the BDL mice and promote liver regeneration via the ID1-WNT2/HGF pathway in PH mice. In addition, Id1 knockdown abolished the protection afforded by UDCA in BDL mice., Conclusions: We conclude that UDCA protects against liver fibrosis by proregeneration via activation of the ID1-WNT2/HGF pathway., (© 2021 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Casein and whey being food supplements have been considered to be used in oral health care products. However, the response of oral cells to micellar casein and whey powder remains unclear. Considering that milk contains the growth factor TGF-β, and lactoperoxidase was recently reported to decrease the expression of inhibitor of DNA-binding (ID) proteins, there is a rationale to assume that casein and whey can also provoke these responses in oral cells. To examine the TGF-β activity, gingival fibroblasts were exposed to reconstituted casein and whey powder from food supplement before the expression of TGF-β target genes were analyzed by reverse transcription-quantitative polymerase chain reaction. Immunoassays were performed for interleukin11 (IL11) in the cell culture supernatant and for TGF-β in the reconstituted casein and whey. We blocked TGF-β by neutralizing the antibody and the TGF-β receptor type I kinase with the inhibitor SB431542. We also showed smad3 phosphorylation and smad2/3 nuclear translocation by Western blot and immunostaining, respectively. Moreover, with reconstituted casein and whey powder, ID1 and ID3 expression analysis was evaluated in HSC2 human oral squamous carcinoma cells. We report here that casein and whey powder caused a robust increase of TGF-β target genes interleukin11 (IL11), NADPH oxidase 4 (NOX4) and proteoglycan4 (PRG4) in gingival fibroblasts that was blocked by SB431542 and the neutralizing antibody. Moreover, casein and whey powder increased the phosphorylation of smad3 and nuclear translocation of smad2/3. No changes of proliferation markers Ki67 and cyclinD1 were observed. Furthermore, reconstituted casein and whey powder decreased ID1 and ID3 expression in the HSC2 oral squamous carcinoma cells. These findings suggest that the processing of milk into casein and whey powder maintains the TGF-β activity and its capacity to regulate ID1 and ID3 genes in oral fibroblasts and oral squamous carcinoma cells, respectively. These data increase the scientific knowledge on the biological activity of casein and whey with a special emphasis on oral health.

Liver sinusoidal endothelial cells (LSECs) play a key role in the initiation and neoangiogenesis of liver regeneration. We presume that the abnormity of the VEGF/VEGFR2 and its pathway gene Id1, Wnt2 and HGF expression in aged LSECs may be an important mechanism to affect liver regeneration of the elderly. LSECs from two different groups (adult and old) were isolated in a rodent model, and observed by SEM and TEM. The adult and old rats were underwent 70% partial hepatectomy. The proliferation of hepatocytes and LSECs were analyzed by Immunofluorescence staining. The expression of VEGF/VEGFR2 and its pathway gene in isolated LSECs and liver tissue after hepatectomy were detected by qRT-PCR and Western blot. There is a decreased number of endothelial fenestrae in the LSECs of the old group, compared to the adult group. The old group had a lower expression of VEGF/VEGFR2 and its pathway gene than the adult groups (p < 0.01). The results of western blot were consistent with those of qRT-PCR. The hepatocytes had a high proliferation rate at first 4 days after hepatectomy, and a significantly higher proliferation rate in the adult group. The LSECs began to proliferate after 4 days of hepatectomy, and showed a quantity advantage in the adult group. The adult group had a significantly higher expression of VEGF/VEGFR2 and its pathway gene after hepatectomy than the old group (p < 0.01). LSCEs turn to be defenestration in structure and have a low expression of VEGF/VEGFR2 and its pathway gene with aging.

Deubiquitylating enzyme ubiquitin-specific protease 1 (USP1) has been reported to be aberrantly overexpressed in cancers, and it plays a critical role in regulating various cellular processes, such as cell proliferation, apoptosis, and cell differentiation. However, the role of USP1 in B-cell acute lymphoblastic leukemia (B-ALL) remains largely undefined. USP1 expression in 30 newly diagnosed B-ALL patients was detected by real-time PCR and western blot. We found that USP1 was generally upregulated in the bone marrow cells derived from B-ALL patients. Knockdown of USP1 by siRNA decreased B-ALL cell growth and induced apoptosis. Similarly, pharmacological inhibition of USP1 by SJB3-019A significantly repressed cell proliferation and triggered B-ALL cell apoptosis. Finally, we found that inhibition of USP1 downregulated the expression of ID1 and p-AKT, and upregulated ID1 expression could reverse the suppressive effects of USP1 inhibitor in B-ALL cells. Taken together, these results demonstrate that USP1 promote B-ALL progression at least partially via the ID1/AKT signaling pathway, and USP1 inhibitors might be promising therapeutic application for B-ALL., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Clear cell renal cell carcinoma (ccRCC) is one of the most common cancers in the world. Our aim is to identify prognostic biomarkers that contribute to the progression of early stage ccRCC and clarify the mechanism. Here, the mRNA microarray expression profile of ccRCC samples was obtained from Gene Expression Omnibus (GEO) (GSE68417). 62 differentially expressed genes (DEGs) were gained by R Studio, including 31 upregulated genes and 31 downregulated genes. Pathway enrichment analysis was performed in DAVID database. Then, the protein-protein interaction network was obtained through STRING database and visualized by Cytoscape. Subsequently, among the network, only inhibitor of DNA Binding 1 (ID1) was significant between low-grade and high-grade ccRCC patients in TCGA data set. After analysis of the corresponding clinical information in R Studio, it is shown that low ID1 expression correlated with poor survival, high probability of tumor metastasis, and relatively high serum calcium. Later, functional enrichment of ID1 in GeneMANIA uncovered that regulating DNA binding is a main characteristic of ID1 in ccRCC, which was validated by Kaplan-Meier curve of ID1 associated genes using KM plotter database and R Studio. Immune infiltration analysis performed by Tumor Immune Estimation Resource (TIMER) revealed that CD8+ T cells and macrophages were prognostic factors. Furthermore, Valproic acid was analyzed to be the most convinced target drug of ID1 identified by Comparative Toxicogenomics Database (CTD). Taken together, ID1, a biomarker of clinical outcome in early stage ccRCC patients, has the potential function of preventing deterioration in ccRCC progression and metastasis., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 Xiangmin Qiu et al.)

Venous malformation (VM) is a type of vascular morphogenic defect in humans with an incidence of 1%. Although gene mutation is considered as the most common cause of VM, the pathogenesis of those without gene mutation remains to be elucidated. Here, we aimed to explore the relation of bone morphogenetic protein 9 (BMP9) and development of VM. At first, we found serum and tissue BMP9 expression in VM patients was significantly lower than that in healthy subjects, detected via enzyme-linked immunosorbent assay. Next, with wound healing assay, transwell assay and tube formation assay, we discovered BMP9 could inhibit migration and enhance tube formation activity of human umbilical vein endothelial cells (HUVECs) via receptor activin receptor-like kinase 1 (ALK1). Besides, BMP9 improved the expression of structural proteins alpha-smooth muscle actin (α-SMA) and Desmin in human umbilical vein smooth muscle cells (HUVSMCs) via activation of the SMAD1/5-ID1 pathway, determined by RNA-based next-generation sequencing, qPCR, immunofluorescence and western blotting. Intriguingly, this effect could be blocked by receptor ALK1 inhibitor, SMAD1/5 inhibitor and siRNAs targeting ID1, verifying the BMP9/ALK1/SMAD1/5/ID1/α-SMA pathway. Meanwhile, knocking out BMP9 in C57BL/6 mice embryo led to α-SMA scarcity in walls of lung and mesenteric vessels, as well as walls of small trachea. BMP9-/- zebrafish also exhibited abnormal vascular maturity, indicating a critical role of BMP9 in vascular maturity and remodeling. Finally, a VM mice model revealed that BMP9 might have therapeutic effect in VM progression. Our study discovered that BMP9 might inhibit the occurrence of VM by strengthening the vessel wall and maintaining endothelium quiescence. These findings provide promising evidences of new therapeutic targets that might be used for the management of VM., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The basic helix-loop-helix (bHLH) transcription factors inhibitor of differentiation 1 ( Id1 ) and inhibitor of differentiation 3 (Id3) (referred to as Id ) have an important role in maintaining the cancer stem cell (CSC) phenotype in the triple-negative breast cancer (TNBC) subtype. In this study, we aimed to understand the molecular mechanism underlying Id control of CSC phenotype and exploit it for therapeutic purposes. We used two different TNBC tumor models marked by either Id depletion or Id1 expression in order to identify Id targets using a combinatorial analysis of RNA sequencing and microarray data. Phenotypically, Id protein depletion leads to cell cycle arrest in the G0/G1 phase, which we demonstrate is reversible. In order to understand the molecular underpinning of Id proteins on the cell cycle phenotype, we carried out a large-scale small interfering RNA (siRNA) screen of 61 putative targets identified by using genomic analysis of two Id TNBC tumor models. Kinesin Family Member 11 ( Kif11 ) and Aurora Kinase A ( Aurka ), which are critical cell cycle regulators, were further validated as Id targets. Interestingly, unlike in Id depletion conditions, Kif11 and Aurka knockdown leads to a G2/M arrest, suggesting a novel Id cell cycle mechanism, which we will explore in further studies. Therapeutic targeting of Kif11 to block the Id1-Kif11 axis was carried out using small molecular inhibitor ispinesib. We finally leveraged our findings to target the Id/Kif11 pathway using the small molecule inhibitor ispinesib in the Id+ CSC results combined with chemotherapy for better response in TNBC subtypes. This work opens up exciting new possibilities of targeting Id targets such as Kif11 in the TNBC subtype, which is currently refractory to chemotherapy. Targeting the Id1-Kif11 molecular pathway in the Id1+ CSCs in combination with chemotherapy and small molecular inhibitor results in more effective debulking of TNBC.

E proteins, a subset of basic helix-loop-helix (bHLH) proteins, are transcription activators and their functions are inhibited by DNA-binding inhibitor (Id) 1-4. Studies have shown that Treg levels are decreased in Id3 knockout mice. Mice over-expressing Id1 in CD4 T cells possessed a greater number of regulatory T cells (Treg) and exhibited attenuated experimental autoimmune encephalomyelitis (EAE). The significance of Id proteins in human systemic lupus erythematosus (SLE) remains unclear. In this study, we systematically analyzed Id transcription in naïve, memory CD4 cells and regulatory T cells in peripheral blood mononuclear cells (PBMCs) in patients with active or inactive SLE. In parallel, Treg subsets in PBMCs were analyzed using different strategies. Id expression levels were correlated with Treg numbers as well as clinical indicators. We found that Id genes expressed in human peripheral CD4 cells were mainly Id2 and Id3. Id3 levels were significantly elevated in CD4 + CD25 hi T cells of patients with active SLE. Likewise, Id3 levels were positively correlated with increased CD4 + FoxP3 + and CD4 + Helios + FoxP3 + Treg cells in these patients. Id3 levels were found to be positively correlated with erythrocyte sedimentation rate (ESR), lupus anticoagulant (LAC), ribosomal antibody and SLE Disease Activity Index (SLEDAI) in patients with active SLE. Mice overexpressing Id1 in CD4 + T cells possessed significantly higher Treg levels in spleen and lower autoantibody concentrations in serum. Our results suggest that during the pathogenesis of SLE, up-regulation of Id3 can promote Treg differentiation to play an inhibitory effect on autoimmune responses., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Cisplatin (Cis) is a choice chemotherapy approach to cervical cancer by inducing DNA adducts and subsequent apoptosis. We have investigated the effects of Cis on Annexin A1 (ANXA1) and inhibitor of DNA binding 1 (ID1) proteins expression to elucidate further mechanisms of Cis actions. Human cervical tissue samples from twenty-four patients, with Cervical Intraepithelial Neoplasia (CIN, stage I, II and III), were evaluated to quantified ANXA1 and ID1 expressions. In vitro, human epidermoid carcinoma of the cervix (SiHa cell line) were treated with Annexin A1 peptide (ANXA1 2-26 ), Cis or Cis + ANXA1 2-26 to evaluate cell proliferation and migration, cytotoxicity of treatments as well as ANXA1 and ID1 modulations by mRNA and protein expression. Our findings showed expression of ID1 and ANXA1 proteins in tissue samples from Cervical Intraepithelial Neoplasia (CIN) patients, with intense immunological identification of ID1 in the CIN III stage. In SiHa cells, treatments with Cis alone or Cis + ANXA1 2-26 , increase mRNA expressions of the ANXA1 and reduced the ID1. In agreement, Cis + ANXA1 2-26 enhanced ANXA1 protein expression and Cis or Cis + ANXA1 2-26 abolished ID1 protein expression. Cell proliferation was reduced after treatment with ANXA1 2-26 peptide and more significant after Cis or Cis + ANXA1 2-26 treatments. These two last treatments reduced cell viability, by inducing late apoptosis, and impaired cell migration. Together, our data highlight endogenous ANXA1 is involved in Cis therapy for cervical cancer., (Copyright © 2020. Published by Elsevier Masson SAS.)

Hepatocellular carcinoma (HCC) is the fourth most common cancer type worldwide, with a poor prognosis and high mortality rate. The aim of the present study was to investigate the mechanisms underlying HCC progression to potentially benefit the development of effective therapies for advanced HCC. The present study reported a novel mechanism that promotes the HCC malignant phenotype, in which the inhibitor of differentiation 1 (ID1) activates the aurora kinase A (AURKA)/Myc signaling pathway. Specifically, a high expression of ID1 promoted a highly malignant phenotype of HCC cells that exhibit enhanced metastatic ability and drug resistance. However, the effects of ID1 were markedly reversed by the AURKA inhibitor VX689 and the Myc inhibitor 10058‑F4. Further studies demonstrated that ID1 competitively binds with anaphase‑promoting complex/cyclosome Cdh1 (APC/CCdh1), which is responsible for ubiquitination‑mediated AURKA protein degradation, resulting in upregulation of AURKA. Increased AURKA expression subsequently enhanced Myc expression at both transcriptional and post‑transcriptional level, leading to amplification of the Myc oncogenic signaling pathway. This novel ID1/AURKA/Myc axis could be a promising therapeutic target for the development of effective therapeutic strategies for advanced HCC.

Although mechanical forces are involved in pressure-overloaded cardiomyopathy, their effects on gene transcription profiles are not fully understood. Here, we used next-generation sequencing (NGS) to investigate changes in genomic profiles after cyclic mechanical stretching of human cardiomyocytes. We found that 85, 87, 32, 29, and 28 genes were differentially expressed after 1, 4, 12, 24, and 48 hours of stretching. Furthermore, 10 of the 29 genes that were up-regulated and 11 of the 28 that were down-regulated after 24 h showed the same changes after 48 h. We then examined expression of the genes that encode serpin family E member 1 (SERPINE1), DNA-binding protein inhibitor 1 (ID1), DNA-binding protein inhibitor 3 (ID3), and CCL2, a cytokine that acts as chemotactic factor in monocytes, in an RT-PCR experiment. The same changes were observed for all four genes after all cyclic stretching durations, confirming the NGS results. Taken together, these findings suggest that cyclical stretching can alter cardiac cell physiology by activating cardiac cell metabolism and impacting cholesterol biosynthesis signaling.

The inhibitor of differentiation (Id) transcription regulators, which are induced in response to oxidative stress, promote cell proliferation and inhibit senescence. Inhibitor of differentiation 1 (Id1) expression is limited to endothelial cells (EC) in the normal mouse kidney and is required for a normal response to injury. Endothelial dysfunction leads to the development of diabetic nephropathy, and so, we hypothesized that endothelial Id1 may help protect against hyperglycemia-induced microvascular injury and nephropathy. Here, we tested this hypothesis by using streptozotocin to induce diabetes in Id1 knockout (KO) mice and WT B6;129 littermates and examining the mice at 3 months. Expression of Id1 was observed to be increased 15-fold in WT kidney EC, and Id1 KO mice exhibited increased mesangial and myofibroblast proliferation, matrix deposition, and albuminuria compared with WT mice. Electron microscopy demonstrated peritubular capillary EC injury and lumen narrowing, and fluorescence microangiography showed a 45% reduction in capillary perfusion area with no reduction in CD31-stained areas in Id1 KO mice. Microarray analysis of EC isolated from WT and KO control and diabetic mice demonstrated activation of senescence pathways in KO cells. Kidneys from KO diabetic mice showed increased histological expression of senescence markers. In addition, premature senescence in cultured KO EC was also seen in response to oxidative stress. In conclusion, endothelial Id1 upregulation with hyperglycemia protects against microvascular injury and senescence and subsequent nephropathy., (© 2020 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Centrosomes are the primary microtubule-organizing centers that are important for mitotic spindle assembly. Centrosome amplification is commonly observed in human cancer cells and contributes to genomic instability. However, it is not clear how centrosome duplication is dysregulated in cancer cells. Here, we report that ATAD5, a replisome protein that unloads PCNA from chromatin as a replication factor C-like complex (RLC), plays an important role in regulating centrosome duplication. ATAD5 is present at the centrosome, specifically at the base of the mother and daughter centrioles that undergo duplication. UAF1, which interacts with ATAD5 and regulates PCNA deubiquitination as a complex with ubiquitin-specific protease 1, is also localized at the centrosome. Depletion of ATAD5 or UAF1 increases cells with over-duplicated centrosome whereas ATAD5 overexpression reduces such cells. Consistently, the proportion of cells showing the multipolar mode of chromosome segregation is increased among ATAD5-depleted cells. The localization and function of ATAD5 at the centrosomes do not require other RLC subunits. UAF1 interacts and co-localizes with ID1, a protein that increases centrosome amplification upon overexpression. ATAD5 depletion reduces interactions between UAF1 and ID1 and increases ID1 signal at the centrosome, providing a mechanistic framework for understanding the role of ATAD5 in centrosome duplication.

Inhibitor of DNA-binding/differentiation (Id) proteins, a family of helix-loop-helix (HLH) proteins that includes four members of Id1 to Id4 in mammalian cells, are critical for regulating cell growth, differentiation, senescence, cell cycle progression, and increasing angiogenesis and vasculogenesis, as well as accelerating the ability of cell migration. Alzheimer's disease (AD), the most common neurodegenerative disease in the adult population, manifests the signs of cognitive decline, behavioral changes, and functional impairment. The underlying mechanisms for AD are not well-clarified yet, but the aggregation of amyloid-beta peptides (Aβs), the major components in the senile plaques observed in AD brains, contributes significantly to the disease progression. Emerging evidence reveals that aberrant cell cycle reentry may play a central role in Aβ-induced neuronal demise. Recently, we have shown that several signaling mediators, including Id1, hypoxia-inducible factor-1 (HIF-1), cyclin-dependent kinases-5 (CDK5), and sonic hedgehog (Shh), may contribute to Aβ-induced cell cycle reentry in postmitotic neurons; furthermore, Id1 and CDK5/p25 mutually antagonize the expression/activity of each other. Therefore, Id proteins may potentially have clinical applications in AD. In this review article, we introduce the underlying mechanisms for cell cycle dysregulation in AD and present some examples, including our own studies, to show different aspects of Id1 in terms of cell cycle reentry and other signaling that may be crucial to alter the neuronal fates in this devastating neurodegenerative disease. A thorough understanding of the underlying mechanisms may provide a rationale to make an earlier intervention before the occurrence of cell cycle reentry and subsequent apoptosis in the fully differentiated neurons during the progression of AD or other neurodegenerative diseases.

Hepatitis B virus (HBV) infection is closely related with the occurrence and development of hepatocellular carcinoma (HCC), in which Hepatitis B virus x protein (HBx) and core protein (HBc) play crucial roles. Additionally, inhibitors of differentiation (Id) proteins exhibited significant correlation with liver cancer development. Here, we identified that HBV dramatically inhibited the expression of Id1 and Id3 in both protein and transcriptional levels for the first time, whereas there was little effect of the virus on Id2. Additionally, two HBV coded protein, HBc and HBx, could reduce the expression of Id1 and Id3 distinctly, whereas the other two viral proteins, HBs and HBp were unable to affect Id1 and Id3 proteins. Both the activity inhibitors and activators further confirmed that HBc inhibited the expression of Id1 and Id3 by BMP/Smad signaling pathway. HBx could interact with both Id1 and Id3 at residues 112-136 of HBx protein, and it could inhibit the two Id proteins by accelerating their degradation. This is the first report about HBc and HBx regulating Id1 and Id3, whereas the detailed mechanism associated with above needed further experiments to clarify., Competing Interests: Declaration of Competing Interest The authors declare that they have no potential conflicts of interest., (Copyright © 2020. Published by Elsevier B.V.)