The biological implications of Yin Yang 1 in the hallmarks of cancer

Oxymatrine Inhibits Liver Cancer Progression by Regulating SIRT1/YY1/GPX4 Axis-Mediated Ferroptosis

Ferroptosis is regarded as a promising cancer therapeutic target. As a major bioactive compound from traditional Chinese medicine (TCM) herb Sophora flavescens Aiton, oxymatrine (OMT) can depress inflammatory factors, reduce iron deposition, and suppress the hub gene or protein expression involved in ferroptosis and inflammation. Additionally, OMT can control collagen deposition in the liver and has a therapeutic effect on liver cancer. This research investigated the action mechanism of the mechanism of the effect of OMT on the process of liver cancer. OMT triggered cell death and restrained cell proliferation in liver cancer cells, along with downregulated levels of Yin Yang 1 (YY1) and glutathione peroxidase 4 (GPX4) and elevated expression of silent information regulator 1 (SIRT1). Moreover, ferroptosis is the main method leading to OMT-induced liver cancer cell death. OMT-induced ferroptosis was reversed after GPX4 and YY1 overexpression or inhibition of SIRT1. Furthermore, the OMT restrained tumor growth through the SIRT1/YY1/GPX4 axis in liver cancer transplantation models. These results indicated that OMT inhibited cell viability and induced ferroptosis of liver cancer cells, involving the regulatory mechanism of the SIRT1/YY1/GPX4 axis.

Identification and characterization of host factor VCPIP1 as a multi-functional positive regulator of hepatitis B virus

Chronic infection with hepatitis B virus (HBV) remains an important public health challenge. Viral covalently closed circular DNA (cccDNA) persists in infected hepatocytes and serves as the template for transcribing all viral RNA species. HBV regulatory protein X (HBx) interacts with other viral and cellular proteins to play diverse functions in viral life cycle, including modulation of cccDNA transcription activity. Here, we used proximity labeling coupled with proteomic analysis to screen for HBx-interacting host proteins. One of the identified candidates, deubiquitinating enzyme valosin-containing protein-interacting protein 1 (VCPIP1), directly binds HBx and stabilizes HBx by reducing its proteasomal degradation, which corroborated a recent report. VCPIP1-mediated upregulation of HBV transcription, antigen expression, and genome replication was demonstrated using a series of HBV replication and infection models. More importantly, VCPIP1 was found to upregulate HBV in the absence of HBx. Mechanistic studies revealed that VCPIP1 HBx-independently associates with HBV enhancer I/X promoter (EnI/Xp) and positively modulates both its promoter and enhancer activities, partially through promoting the binding of YY1 transcription factor to EnI/Xp. Results presented here expand the recently described role of VCPIP1 in HBV life cycle and establish it as a multi-functional positive regulator of this virus.

IMPORTANCE

Hepatitis B virus (HBV) encodes the regulatory protein HBx that plays crucial roles in viral life cycle and cellular processes through interacting with viral and cellular proteins. Identifying HBx-interacting proteins may reveal novel aspects of host-virus interactions. In this work, proximity labeling coupled with proteomic analysis identified multiple HBx-interacting host factors, and among these, valosin-containing protein-interacting protein 1 (VCPIP1) was confirmed to directly bind HBx and reduce its proteasomal degradation, corroborating a recent report. In addition to upregulating HBx-expressing HBV, we showed that VCPIP1 also positively regulates mutant HBV lacking HBx expression. This novel HBx-independent function of VCPIP1 was shown to involve its association with one viral promoter/enhancer element, which upregulated the latter's promoter and enhancer activities. These results establish VCPIP1 as a positive regulator of HBV that acts through multiple, diverse mechanisms and might also contribute toward revealing novel cellular functions of VCPIP1.

miR-130a-3p enhances autophagy through the YY1/PI3K/AKT/mTOR signaling pathway to regulate macrophage polarization and alleviate diabetic retinopathy

AIMS/INTRODUCTION

Diabetic retinopathy (DR) is a common complication of diabetes that can lead to poor vision and blindness. This study aimed to explore the mechanism of action of miR-130a-3p in DR progression.

MATERIALS AND METHODS

In this study, we administered a single intraperitoneal injection of 100 mg/kg streptozotocin (STZ) to construct a DR mouse model, and induced a human monocyte cell line (THP-1) to differentiate into M0 macrophages, after which the M0 macrophages were cultured with 30 mM high glucose (HG) as a model of inflammation. The relative gene and protein levels were validated by RT-qPCR and western blotting. Macrophage polarization and retinal damage in the mice were tested using ELISA, MDC staining, immunofluorescence staining, and HE staining.

RESULTS

The results revealed that the expression of miR-130a-3p was low in M1 macrophages, whereas the expression of miR-130a-3p was high in M2 macrophages, and the level of miR-130a-3p was reduced after HG treatment of macrophages. The overexpression of miR-130a-3p attenuated HG- or STZ-induced inflammation, promoted macrophage autophagy, inhibited M1 polarization of macrophages, and attenuated the progression of DR. In addition, YY1 was the downstream target gene of miR-130a-3p, and overexpression of miR-130a-3p inhibited YY1 expression. However, overexpression of YY1 weakened the effect of miR-130a-3p mimic. After further treatment with the PI3K/Akt/mTOR pathway activator 740 Y-P, the effect of YY1 knockdown was weakened, macrophage autophagy was inhibited, and M1 polarization and inflammation were promoted.

CONCLUSION

miR-130a-3p inhibited the activation of the PI3K/Akt/mTOR pathway by downregulating YY1 expression, thus facilitating macrophage autophagy, inhibiting M1 polarization and the inflammatory response of macrophages, and finally attenuating the progression of DR. The results of this study provide theoretical support for the use of miR-130a-3p as a new target for the treatment of DR.

Targeting the transcription factor YY1 is synthetic lethal with loss of the histone demethylase KDM5C

An understanding of the enzymatic and scaffolding functions of epigenetic modifiers is important for the development of epigenetic therapies for cancer. The H3K4me2/3 histone demethylase KDM5C has been shown to regulate transcription. The diverse roles of KDM5C are likely determined by its interacting partners, which are still largely unknown. In this study, we screen for KDM5C-binding proteins and show that YY1 interacts with KDM5C. A synergistic antitumor effect is exerted when both KDM5C and YY1 are depleted, and targeting YY1 appears to be a vulnerability in KDM5C-deficient cancer cells. Mechanistically, KDM5C promotes global YY1 chromatin recruitment, especially at promoters. Moreover, an intact KDM5C JmjC domain but not KDM5C histone demethylase activity is required for KDM5C-mediated YY1 chromatin binding. Transcriptional profiling reveals that dual inhibition of KDM5C and YY1 increases transcriptional repression of cell cycle- and apoptosis-related genes. In summary, our work demonstrates a synthetic lethal interaction between YY1 and KDM5C and suggests combination therapies for cancer treatments.

Pericytes Modulate Third-Generation Tyrosine Kinase Inhibitor Sensitivity in EGFR-Mutated Lung Cancer Cells Through IL32-β5-Integrin Paracrine Signaling

EGFR-mutated lung cancer patients sometimes display restricted responses to third-generation tyrosine kinase inhibitors (TKIs), potentially attributable to undervalued input from stromal cells, notably pericytes (PCs). The study shows that PCs isolated from EGFR-mutated patients have a unique secretome profile, notably secreting IL32 and affecting signaling pathways and biological processes linked to TKI sensitivity. Clinical evidence, supported by single-cell RNA sequencing and multiplex immunostaining of tumor tissues, confirms the presence of IL32-expressing pericytes closely interacting with β5-integrin-expressing cancer cells in EGFR-mutated patients, impacting therapeutic response and prognosis. Co-culture and conditioned medium experiments demonstrate that PCs reduce TKI effectiveness in EGFR-mutated cancer cells, a reversible phenomenon through silencing IL32 expression in PCs or depleting the IL32 receptor β5-integrin on cancer cells, thereby restoring cancer cell sensitivity. Mechanistically, it is shown that YY1 signaling upregulates IL32 secretion in PCs, subsequently activating the β5-integrin-Src-Akt pathway in EGFR-mutated cancer cells, contributing to their TKI sensitivity. In animal studies, co-injection of cancer cells with PCs compromises TKI effectiveness, independently of blood vessel functions, while inhibition of β5-integrin restores tumor cell sensitivity. Overall, the findings highlight direct crosstalk between cancer cells and pericytes, impacting TKI sensitivity via IL32-β5-integrin paracrine signaling, proposing an enhanced therapeutic approach for EGFR-mutated patients.

New finding based on Comparative Toxicogenomics Database: Hepatic YY1 mediates drug-induced liver injury

BACKGROUND

YY1 plays a crucial part in the onset and progression of numerous liver diseases, yet the significant contribution of YY1 to drug-induced liver injury (DILI) appears to have been underestimated by researchers.

PURPOSE

To reveal the underlying role of YY1 in DILI.

METHOD

The compounds that interact with YY1 were queried in the Comparative Toxicogenomics Database (CTD), with the majority found to be hepatotoxic, which includes certain widely used drugs. Molecular docking and SPR characterized the robust binding of hepatotoxic compounds to YY1. The duty of YY1 in DILI was investigated in Diosbulbin B (DIOB), a recently identified hepatotoxic compound that tightly associates with YY1, and further validated on ANIT, LCA, APAP, and CDDP. Transcriptomic analysis disclosed the underlying mechanisms involved in DIOB-induced liver injury. RT-qPCR, immunohistochemistry, immunofluorescence, western blotting, and cellular transfection techniques were employed to validate the specific mechanism.

RESULTS

Among the 94 compounds affecting YY1 expression in the CTD, 59 compounds exhibited hepatotoxicity, showing close interactions with YY1 and almost consistent binding sites by molecular docking. The SPR validated the tough binding of several hepatotoxic compounds to YY1, including five FDA-approved hepatotoxic drugs. Mechanistically, the involvement of YY1 in DILI was uncovered through the cholestasis lens, mice hepatic YY1 was up-regulated by hepatotoxic DIOB and transcriptionally inhibited FXR and its downstream BSEP and MRP2 expression, initiating early in cholestatic liver injury and persisting to drive the progression of cholestasis. ANIT and LCA-induced model of cholestasis provided evidence for the hypothesis that YY1 frequently mediates drug induced cholestasis (DIC). APAP and CDDP indicated that YY1 may also be involved in hepatocellular and mixed type DILI.

CONCLUSION

YY1 widely mediated the development of DIC and also might be engaged in other types of DILI. YY1 presented a common target for hepatotoxic medications and the targeting of liver YY1 for drug development may offer a novel approach for managing DILI.

Genome-Wide Profiling of H3K27ac Identifies TDO2 as a Pivotal Therapeutic Target in Metabolic Associated Steatohepatitis Liver Disease

H3K27ac has been widely recognized as a representative epigenetic marker of active enhancer, while its regulatory mechanisms in pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) remain elusive. Here, a genome-wide comparative study on H3K27ac activities and transcriptome profiling in high fat diet (HFD)-induced MASLD model is performed. A significantly enhanced H3K27ac density with abundant alterations of regulatory transcriptome is observed in MASLD rats. Based on integrative analysis of ChIP-Seq and RNA-Seq, TDO2 is identified as a critical contributor for abnormal lipid accumulation, transcriptionally activated by YY1-promoted H3K27ac. Furthermore, TDO2 depletion effectively protects against hepatic steatosis. In terms of mechanisms, TDO2 activates NF-κB pathway to promote macrophages M1 polarization, representing a crucial event in MASLD progression. A bovine serum albumin nanoparticle is fabricated to provide sustained release of Allopurinol (NPs-Allo) for TDO2 inhibition, possessing excellent biocompatibility and desired targeting capacity. Venous injection of NPs-Allo robustly alleviates HFD-induced metabolic disorders. This study reveals the pivotal role of TDO2 and its underlying mechanisms in pathogenesis of MASLD epigenetically and genetically. Targeting H3K27ac-TDO2-NF-κB axis may provide new insights into the pathogenesis of abnormal lipid accumulation and pave the way for developing novel strategies for MASLD prevention and treatment.

Glucose-induced LINC01419 reprograms the glycolytic pathway by recruiting YBX1 to enhance PDK1 mRNA stability in hepatocellular carcinoma

Metabolic reprogramming provides the necessary energy for the development of malignant tumours and is emerging as a novel tumour treatment strategy. However, the widespread expression of metabolic enzymes in diverse cell types makes the development of specific drugs that target cancer cells without affecting normal cellular functions challenging. Accumulating evidence has demonstrated the essential roles of long non-coding RNAs (lncRNAs) in the regulatory network associated with glucose metabolism in tumour cells. The mechanism and therapeutic potential of cancer-specific lncRNAs in modulating tumour glucose metabolism warrant in-depth exploration. Here we revealed that glucose-induced LINC01419 promoted the growth and metastasis of HCC cells by driving metabolic reprogramming. Mechanistically, LINC01419 directly interacted with Y-box binding protein 1 (YBX1) in the cytoplasm and facilitated its binding to PDK1 mRNA, thus enhancing PDK1 mRNA stability and increasing lactate production. Furthermore, YY1 contributed to the transcriptional activation of LINC01419 in HCC under high-glucose conditions. Notably, administration of an N-acetylgalactosamine (GalNAc)-conjugated siRNA specifically targeting LINC01419 markedly retarded the growth of orthotopic xenograft tumours. These findings provide evidence for an unprecedented regulatory mechanism of LINC01419 involving metabolic reprogramming in human cancer. The newly identified LINC01419/YBX1-PDK1 axis may represent a promising therapeutic target for HCC. Moreover, GalNAc-siLINC01419 holds significant potential for clinical application. KEY POINTS: This study highlights the considerable regulatory role of LINC01419 in the metabolism of HCC. The newly identified LINC01419/YBX1-PDK1 axis constitutes a valuable target. Hepatic-specific delivery of GalNAc-siLINC01419 presents a promising therapeutic strategy for HCC.

YY1 downregulation underlies therapeutic response to molecular targeted agents

During targeted treatment, oncogene-addicted tumor cells often evolve from an initial drug-sensitive state through a drug-tolerant persister bottleneck toward the ultimate emergence of drug-resistant clones. The molecular basis underlying this therapy-induced evolutionary trajectory has not yet been completely elucidated. Here, we employed a multifaceted approach and implicated the convergent role of transcription factor Yin Yang 1 (YY1) in the course of diverse targeted kinase inhibitors. Specifically, pharmacological perturbation of the receptor tyrosine kinase (RTK)/mitogen-activated protein kinase (MAPK) pathway resulted in the downregulation of YY1 transcription, which subsequently resumed upon therapeutic escape. Failure to decrease YY1 subverted cytotoxic effects, whereas elimination of residual YY1 maximized anticancer efficacy and forestalled the emergence of drug resistance. Mechanistically, YY1 was uncovered to dictate cell cycle and autophagic programs. Immunohistochemical analysis on a wide spectrum of clinical specimens revealed that YY1 was ubiquitously expressed across lung adenocarcinomas and exhibited anticipated fluctuation in response to corresponding RTK/MAPK inhibition. These findings advance our understanding of targeted cancer management by highlighting YY1 as a determinant node in the context of genotype-directed agents.

ENAH transcriptionally activated by YY1 promotes growth and invasion of laryngocarcinoma cells through PI3K/AKT signaling

BACKGROUND

Laryngocarcinoma is a common malignancy in the upper respiratory tract. Enabled homolog (ENAH) is an actin-binding protein that is associated with the development of various cancers. However, its role and mechanism in laryngocarcinoma remain unknown.

METHODS

The ENAH level in laryngocarcinoma was examined in silico, in vitro and in vivo. The prognostic analysis of the ENAH level was assessed on laryngocarcinoma patients. Gain- and loss-of-function assays were conducted in AMC-HN-8 and TU686 cells. Sh-ENAH-containing AMC-HN-8 cells were implanted into naked mice. The role and mechanism of ENAH in laryngocarcinoma were investigated by CCK-8, transwell, immunofluorescence, dual luciferase, RT-qPCR, immunohistochemistry, and western blotting experiments.

RESULTS

The ENAH level was upregulated in laryngocarcinoma, which predicted a poor prognosis in laryngocarcinoma patients. Gain- and loss-of-function results showed that ENAH promoted proliferation, invasion and EMT of laryngocarcinoma cells. Moreover, ENAH was transcriptionally activated by YY1, and YY1/ENAH axis enhanced these malignant progresses of laryngocarcinoma cells. Besides, ENAH activated the PI3K/AKT pathway, and 740Y-P abolished the accelerative role of ENAH in proliferation, invasion and EMT of laryngocarcinoma cells. Furthermore, knockdown of ENAH reduced tumor size and weight, and the expression level of vimentin and PI3K/AKT pathway in tumor-bearing mice.

CONCLUSION

ENAH transcriptionally activated by YY1 promotes cell growth, invasion and EMT of laryngocarcinoma through the activation of PI3K/AKT signaling.

NEDD4L Inhibits the Proliferation and Migration of Keloid Fibroblasts by Regulating YY1 Ubiquitination-Mediated Glycolytic Metabolic Reprogramming

Keloid scarring is a complex fibroproliferative disorder characterised by excessive fibroblast proliferation. Inhibition of cellular glycolysis effectively suppresses the proliferation of keloid fibroblasts (KFs). Neural precursor cell-expressed developmentally downregulated gene 4-like (NEDD4L), a ubiquitin ligase, regulates cell proliferation in different diseases. This study investigated the effects of NEDD4L on glucose metabolism, proliferation and migration in KFs. Primary KFs were isolated from keloid skin tissues obtained from patients with active-stage keloids. Cell transfection was used to upregulate or downregulate NEDD4L and Yin Yang 1 (YY1) in KFs. Protein expression was assessed by immunohistochemistry and western blotting. The viability, proliferative capacity and migration ability of KFs were evaluated using the MTT method and the EdU and wound healing assays, respectively. The regulatory effect of NEDD4L on YY1 ubiquitination was examined by coimmunoprecipitation. The interaction between YY1 and hexokinase 2 (HK2) was confirmed by a dual-luciferase reporter assay. NEDD4L was downregulated, whereas YY1 and HK2 were highly expressed in keloid tissues compared with normal skin. Overexpression of NEDD4L inhibited the proliferation and migration of KFs. NEDD4L promoted YY1 degradation in KFs by inducing its ubiquitination. Upregulation of YY1 induced glucose consumption and lactate production in KFs via the transcriptional regulation of HK2. Increased expression of YY1 reversed the reduced viability, proliferation, and migration of KFs overexpressing NEDD4L. YY1 also reversed the NEDD4L-induced inhibition of glucose consumption and lactate production in KFs. Additionally, an in vivo study confirmed the inhibitory roles of NEDD4L overexpression and YY1 knockdown in keloid formation. NEDD4L suppressed the viability, proliferation and migration of KFs by regulating YY1 ubiquitination-mediated glycolysis through HK2. These findings suggest a novel regulatory axis, NEDD4L/YY1/HK2, that mediates glucose metabolism in keloid formation.

The impacts of cancer treatment on lifestyle habits and mental health in Vietnamese women: an exploratory qualitative study

AIMS

This qualitative study explores the experiences of women after cancer treatment in terms of habit changes and mental health impact.

METHOD

The study involved 10 women who had undergone cancer treatment, recruited from three major hospitals in Hanoi, Vietnam. Data were collected through semi-structured interviews, which were transcribed and analyzed using thematic analysis.

RESULTS

The findings of the study shed light on the various factors influencing lifestyle behavior and mental health changes among women after cancer treatment. Ten participants, aged 39 to 64 years, shared experiences including dietary changes, sleep disruptions, and reliance on non-scientific sources for health decisions. Initially shocked by their diagnosis, many transitioned to acceptance, adopting a "giving-in" attitude. Cultural beliefs, word-of-mouth sharing, and social support networks played significant roles in shaping post-treatment lifestyle changes, coping mechanisms, information-seeking behaviors, and mental health.

CONCLUSION

The study highlights the need for accessible and scientifically verified information for women after cancer treatment to make informed decisions about their health. It emphasizes the importance of addressing traditional beliefs and promoting evidence-based practices. Moreover, the study underscores the importance of social support and relationships in coping with the challenges of post-cancer experiences.

Multi-Omics Analysis Revealed the rSNPs Potentially Involved in T2DM Pathogenic Mechanism and Metformin Response

The goal of our study was to identify and assess the functionally significant SNPs with potentially important roles in the development of type 2 diabetes mellitus (T2DM) and/or their effect on individual response to antihyperglycemic medication with metformin. We applied a bioinformatics approach to identify the regulatory SNPs (rSNPs) associated with allele-asymmetric binding and expression events in our paired ChIP-seq and RNA-seq data for peripheral blood mononuclear cells (PBMCs) of nine healthy individuals. The rSNP outcomes were analyzed using public data from the GWAS (Genome-Wide Association Studies) and Genotype-Tissue Expression (GTEx). The differentially expressed genes (DEGs) between healthy and T2DM individuals (GSE221521), including metformin responders and non-responders (GSE153315), were searched for in GEO RNA-seq data. The DEGs harboring rSNPs were analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). We identified 14,796 rSNPs in the promoters of 5132 genes of human PBMCs. We found 4280 rSNPs to associate with both phenotypic traits (GWAS) and expression quantitative trait loci (eQTLs) from GTEx. Between T2DM patients and controls, 3810 rSNPs were detected in the promoters of 1284 DEGs. Based on the protein-protein interaction (PPI) network, we identified 31 upregulated hub genes, including the genes involved in inflammation, obesity, and insulin resistance. The top-ranked 10 enriched KEGG pathways for these hubs included insulin, AMPK, and FoxO signaling pathways. Between metformin responders and non-responders, 367 rSNPs were found in the promoters of 131 DEGs. Genes encoding transcription factors and transcription regulators were the most widely represented group and many were shown to be involved in the T2DM pathogenesis. We have formed a list of human rSNPs that add functional interpretation to the T2DM-association signals identified in GWAS. The results suggest candidate causal regulatory variants for T2DM, with strong enrichment in the pathways related to glucose metabolism, inflammation, and the effects of metformin.

Host cells reprogram lipid droplet synthesis through YY1 to resist PRRSV infection

Metabolism in host cells can be modulated after viral infection, favoring viral survival or clearance. Here, we report that lipid droplet (LD) synthesis in host cells can be modulated by yin yang 1 (YY1) after porcine reproductive and respiratory syndrome virus (PRRSV) infection, resulting in active antiviral activity. As a ubiquitously distributed transcription factor, there was increased expression of YY1 upon PRRSV infection both in vitro and in vivo. YY1 silencing promoted the replication of PRRSV, whereas YY1 overexpression inhibited PRRSV replication. PRRSV infection led to a marked increase in LDs, while YY1 knockout inhibited LD synthesis, and YY1 overexpression enhanced LD accumulation, indicating that YY1 reprograms PRRSV infection-induced intracellular LD synthesis. We also showed that the viral components do not colocalize with LDs during PRRSV infection, and the effect of exogenously induced LD synthesis on PRRSV replication is nearly lethal. Moreover, we demonstrated that YY1 affects the synthesis of LDs by regulating the expression of lipid metabolism genes. YY1 negatively regulates the expression of fatty acid synthase (FASN) to weaken the fatty acid synthesis pathway and positively regulates the expression of peroxisome proliferator-activated receptor gamma (PPARγ) to promote the synthesis of LDs, thus inhibiting PRRSV replication. These novel findings indicate that YY1 plays a crucial role in regulating PRRSV replication by reprogramming LD synthesis. Therefore, our study provides a novel mechanism of host resistance to PRRSV and suggests potential new antiviral strategies against PRRSV infection.IMPORTANCEPorcine reproductive and respiratory virus (PRRSV) has caused incalculable economic damage to the global pig industry since it was first discovered in the 1980s. However, conventional vaccines do not provide satisfactory protection. It is well known that viruses are parasitic pathogens, and the completion of their replication life cycle is highly dependent on host cells. A better understanding of host resistance to PRRSV infection is essential for developing safe and effective strategies to control PRRSV. Here, we report a crucial host antiviral molecule, yin yang 1 (YY1), which is induced to be expressed upon PRRSV infection and subsequently inhibits virus replication by reprogramming lipid droplet (LD) synthesis through transcriptional regulation. Our work provides a novel antiviral mechanism against PRRSV infection and suggests that targeting YY1 could be a new strategy for controlling PRRSV.

The anti-non-small cell lung cancer effect of Diosbulbin B: Targeting YY1 induced cell cycle arrest and apoptosis

BACKGROUND

Toxic components frequently exhibit unique characteristics and activities, offering ample opportunities for the advancement of anti-cancer medications. As the main hepatotoxic component of Dioscorea bulbifera L. (DB), Diosbulbin B (DIOB) has been widely studied for its anti-tumor activity at nontoxic doses. However, the effectiveness and mechanism of DIOB against non-small cell lung cancer (NSCLC) remains unclear.

PURPOSE

To evaluate the anti-NSCLC activity of DIOB and to elucidate the specific mechanism of action.

METHOD

The effect of DIOB on NSCLCL in vitro was evaluated through CCK8, colony formation, and flow cytometry. The in vivo efficacy and safety of DIOB in treating NSCLC were assessed using various techniques, including HE staining, tunel staining, immunohistochemistry, and biochemical index detection. To understand the underlying mechanism, cell transfection, western blotting, molecular docking, cellular thermal shift assay (CESTA), and surface plasmon resonance (SPR) were employed for investigation.

RESULTS

DIOB effectively hindered the progression of NSCLC both in vitro and in vivo settings at a no-observed-adverse-effect concentration (NOAEC) and a safe dosage. Specifically, DIOB induced significant G0/G1 phase arrest and apoptosis in A549, PC-9, and H1299 cells, while also notably inhibiting the growth of subcutaneous tumors in nude mice. Mechanistically, DIOB could directly interact with oncogene Yin Yang 1 (YY1) and inhibit its expression. The reduction in YY1 resulted in the triggering of the tumor suppressor P53, which induced cell cycle arrest and apoptosis in NSCLC cells by inhibiting the expression of Cyclin A2, B2, CDK1, CDK2, CDK4, BCL-2, and inducing the expression of BAX. In NSCLC cells, the induction of G0/G1 phase arrest and apoptosis by DIOB was effectively reversed when YY1 was overexpressed or P53 was knocked down. Importantly, we observed that DIOB exerted the same effect by directly influencing the expression of YY1-regulated c-Myc and BIM, particularly in the absence of P53.

CONCLUSION

For the inaugural investigation, this research unveiled the anti-NSCLC impact of DIOB, alongside its fundamental mechanism. DIOB has demonstrated potential as a treatment agent for NSCLC due to its impressive efficacy in countering NSCLC.

A mutual regulatory loop between transcription factor Yin Yang 1 and hepatitis B virus replication influences chronic hepatitis B

Hepatitis B virus (HBV) infections pose a major threat to human health. HBV can upregulate the expression of the transcription factor Yin Yang 1 (YY1) in in vitro cytological experiments, suggesting an association between YY1 and HBV infection. However, data on YY1 expression in chronic hepatitis B (CHB) patients are lacking. In this study, we aimed to assess the correlation between YY1 expression and HBV infection. We detected serum YY1 levels in 420 patients with chronic HBV infection, 30 patients with chronic hepatitis C virus infection, and 32 healthy controls using an enzyme-linked immunosorbent assay. The correlation between YY1 levels and clinical parameters was analyzed. Meanwhile, the changes of YY1 before and after interferon or entecavir treatment were analyzed. YY1 levels in the liver tissues were detected using immunofluorescence staining. The expression of YY1 in HBV-expressing cells was detected through western blotting. Meanwhile, we explored the effects of YY1 on HBV replication and gene expression. We found that YY1 was highly expressed in the serum and liver tissues of CHB patients. Serum YY1 levels positively correlated with HBV DNA and hepatitis B surface antigen (HBsAg). Additionally, HBV DNA levels increased but HBsAg levels decreased after HBV-expressing cells overexpress YY1. In conclusion, our study demonstrates that YY1 plays an important role in HBV replication and gene expression, providing a potential target for the treatment of CHB.

Energy stress-induced circDDX21 promotes glycolysis and facilitates hepatocellular carcinogenesis

Cancer cells undergo metabolic reprogramming in response to hostile microenvironments, such as energy stress; however, the underlying mechanisms remain largely unclear. It is also unknown whether energy stress-responsive circular RNA (circRNA) is involved in the regulation of glucose metabolism. Here we report that circDDX21 is upregulated in response to glucose deprivation by the transcription factor c-Myc. Functionally, circDDX21 is shown to promote glycolysis by increasing PGAM1 expression. Mechanistically, circDDX21 interacts with the RNA binding protein PABPC1, disrupting its association with the ubiquitin E3 ligase MKRN3. This disassociation attenuates MKRN3-mediated PABPC1 ubiquitination and enhances the binding of PABPC1 to PGAM1 mRNA, thereby leading to PGAM1 mRNA stabilization. The ability of the circDDX21-PGAM1 axis to promote hepatocellular carcinogenesis is validated in a xenograft mouse model. Additionally, in clinical hepatocellular carcinoma tissues, there is a positive correlation between circDDX21 and PGAM1 expression. These findings establish circDDX21 as an important regulator of glycolysis and suggest circDDX21 as a potential therapeutic target for hepatocellular carcinoma.

RNA polymerase I subunit D activated by Yin Yang 1 transcription promote cell proliferation and angiogenesis of colorectal cancer cells

This study aims to explore possible effect of RNA polymerase I subunit D (POLR1D) on proliferation and angiogenesis ability of colorectal cancer (CRC) cells and mechanism herein. The correlation of POLR1D and Yin Yang 1 (YY1) expressions with prognosis of CRC patients in TCGA database was analyzed. Quantitative realtime polymerase chain reaction (qRT-PCR) and Western blot were applied to detect expression levels of POLR1D and YY1 in CRC cell lines and CRC tissues. SW480 and HT- 29 cells were transfected with si-POLR1D or pcDNA3.1-POLR1D to achieve POLR1D suppression or overexpression before cell migration, angiogenesis of human umbilical vein endothelial cells were assessed. Western blot was used to detect expressions of p38 MAPK signal pathway related proteins and interaction of YY1 with POLR1D was confirmed by dual luciferase reporter gene assay and chromatin immunoprecipitation (ChIP). TCGA data showed that both POLR1D and YY1 expressions were up-regulated in CRC patients. High expression of POLR1D was associated with poor prognosis of CRC patients. The results showed that POLR1D and YY1 were highly expressed in CRC cell lines. Inhibition or overexpression of POLR1D can respectively suppress or enhance proliferation and angiogenesis of CRC cells. YY1 inhibition can suppress CRC progression and deactivate p38 MAPK signal pathway, which can be counteracted by POLR1D overexpression. JASPAR predicted YY1 can bind with POLR1D promoter, which was confirmed by dual luciferase reporter gene assay and ChIP. YY1 transcription can up-regulate POLR1D expression to activate p38 MAPK signal pathway, thus promoting proliferation and angiogenesis ability of CRC cells.

YY1: a key regulator inhibits gastric cancer ferroptosis and mediating apatinib-resistance

OBJECTIVE

Gastric cancer (GC) stands as a prevalent and deadly global malignancy. Despite its role as a preoperative neoadjuvant therapy, Apatinib's effectiveness is curtailed among GC patients exhibiting elevated YY1 expression. YY1's connection to adverse prognosis, drug resistance, and GC metastasis is established, yet the precise underlying mechanisms remain elusive. This study aims to unravel potential pathogenic pathways attributed to YY1.

DESIGN

Utilizing bioinformatics analysis, we conducted differentially expressed genes, functional annotation, and pathway enrichment analyses, and further validation through cellular and animal experiments.

RESULTS

Higher YY1 expression correlated with diminished postoperative progression-free survival (PFS) and disease-specific survival (DSS) rates in TCGA analysis, identifying YY1 as an independent DSS indicator in gastric cancer (GC) patients. Notably, YY1 exhibited significantly elevated expression in tumor tissues compared to adjacent normal tissues. Bioinformatics analysis revealed noteworthy differentially expressed genes (DEGs), transcriptional targets, factors, and co-expressed genes associated with YY1. LASSO Cox analysis unveiled Transferrin as a prospective pivotal protein regulated by YY1, with heightened expression linked to adverse DSS and PFS outcomes. YY1's role in governing the p53 signaling pathway and ferroptosis in GC cells was further elucidated. Moreover, YY1 overexpression dampened immune cell infiltration within GC tumors. Additionally, YY1 overexpression hindered GC cell ferroptosis and mediated Apatinib resistance via the p53 pathway. Remarkably, IFN-a demonstrated efficacy in reversing Apatinib resistance and immune suppression in GC tissues.

CONCLUSIONS

Our findings underscore the pivotal role of YY1 in driving GC progression and influencing prognosis, thus pinpointing it as a promising therapeutic target to enhance patient outcomes.

Clinicopathological Significance and Expression Pattern of Bcl2 in Breast Cancer: A Comprehensive in silico and in vitro Study

B-cell lymphoma/leukemia gene-2 (Bcl-2) is the primary proto-oncogene that has been shown to work by preventing apoptosis/programmed cell death. Bcl-2 combines a variety of cell-generated signals associated to the survival and death of cells. In glioma, lung, and breast cancer, Bcl-2 over-expression has been linked to an increase in invasion and migration. Many treatment regimens that target Bcl2 have been established and approved, and thus increasing the survival rates of the patients. The primary goal of this research was to recognize new therapeutic compounds that target Bcl2 and assess Bcl2 expression pattern in BC patients. We used various bioinformatic tools as well as several in vitro assays to look out the expression and inhibition of Bcl2 in BC. Our study depicted that Bcl2 had a strong connection with tumour stroma, notably with suppressor cells originating from myeloid tissues. Moreover, in vitro and in silico research identified Paclitaxel as a promising natural substance that targets Bcl2. Overall, this work shows that Bcl2 overexpression accelerates the development of BC, and that targeting Bcl2 in combination with other drugs will dramatically improve BC patient's response to treatment and prevent the emergence of drug resistance.

Targeting the PHF8/YY1 axis suppresses cancer cell growth through modulation of ROS

High levels of mitochondrial reactive oxygen species (mROS) are linked to cancer development, which is tightly controlled by the electron transport chain (ETC). However, the epigenetic mechanisms governing ETC gene transcription to drive mROS production and cancer cell growth remain to be fully characterized. Here, we report that protein demethylase PHF8 is overexpressed in many types of cancers, including colon and lung cancer, and is negatively correlated with ETC gene expression. While it is well known to demethylate histones to activate transcription, PHF8 demethylates transcription factor YY1, functioning as a co-repressor for a large set of nuclear-coded ETC genes to drive mROS production and cancer development. In addition to genetically ablating PHF8, pharmacologically targeting PHF8 with a specific chemical inhibitor, iPHF8, is potent in regulating YY1 methylation, ETC gene transcription, mROS production, and cell growth in colon and lung cancer cells. iPHF8 exhibits potency and safety in suppressing tumor growth in cell-line- and patient-derived xenografts in vivo. Our data uncover a key epigenetic mechanism underlying ETC gene transcriptional regulation, demonstrating that targeting the PHF8/YY1 axis has great potential to treat cancers.

YY1 modulates the radiosensitivity of esophageal squamous cell carcinoma through KIF3B-mediated Hippo signaling pathway

Radiotherapy is an important strategy in the comprehensive treatment of esophageal squamous cell carcinoma (ESCC). However, effectiveness of radiotherapy is still restricted by radioresistance. Herein, we aimed to understand the mechanisms underlying ESCC radioresistance, for which we looked into the potential role of YY1. YY1 was upregulated in radioresistant tissues and correlated with poor prognosis of patients with ESCC. YY1 depletion enhanced the radiosensitivity of ESCC in vitro and in vivo. Multi-group sequencing showed that downregulation of YY1 inhibited the transcriptional activity of Kinesin Family Member 3B (KIF3B), which further activated the Hippo signaling pathway by interacting with Integrin-beta1 (ITGB1). Once the Hippo pathway was activated, its main effector, Yes-associated protein 1 (YAP1), was phosphorylated in the cytoplasm and its expression reduced in the nucleus, thus enhancing the radiosensitivity by regulating its targeted genes. Our study provides new insights into the mechanisms underlying ESCC radioresistance and highlights the potential role of YY1 as a therapeutic target for ESCC.

The Emerging Roles of the Metabolic Regulator G6PD in Human Cancers

Metabolic reprogramming, especially reprogrammed glucose metabolism, is a well-known cancer hallmark related to various characteristics of tumor cells, including proliferation, survival, metastasis, and drug resistance. Glucose-6-phosphate dehydrogenase (G6PD) is the first and rate-limiting enzyme of the pentose phosphate pathway (PPP), a branch of glycolysis, that converts glucose-6-phosphate (G6P) into 6-phosphogluconolactone (6PGL). Furthermore, PPP produces ribose-5-phosphate (R5P), which provides sugar-phosphate backbones for nucleotide synthesis as well as nicotinamide adenine dinucleotide phosphate (NADPH), an important cellular reductant. Several studies have shown enhanced G6PD expression and PPP flux in various tumor cells, as well as their correlation with tumor progression through cancer hallmark regulation, especially reprogramming cellular metabolism, sustaining proliferative signaling, resisting cell death, and activating invasion and metastasis. Inhibiting G6PD could suppress tumor cell proliferation, promote cell death, reverse chemoresistance, and inhibit metastasis, suggesting the potential of G6PD as a target for anti-tumor therapeutic strategies. Indeed, while challenges-including side effects-still remain, small-molecule G6PD inhibitors showing potential anti-tumor effect either when used alone or in combination with other anti-tumor drugs have been developed. This review provides an overview of the structural significance of G6PD, its role in and regulation of tumor development and progression, and the strategies explored in relation to G6PD-targeted therapy.

Epigenetic regulation of enhancer of zeste homolog 2 (EZH2) -Yin Yang 1 (YY1) axis in cancer

In accordance with the World Health Organization, cancer is the second leading cause of death in patients. In recent years, the number of cancer patients has been growing, and the occurrence of cancer in people is becoming more common, primarily due to lifestyle factors. Yin Yang 1 (YY1) is a transcription factor that is widespread throughout. It is a zinc finger protein, falling under the GLI-Kruppel class. YY1 is known to regulate transcriptional activation and repression of various genes associated with different cellular processes such as DNA repair, autophagy, cell survival and apoptosis, and cell division. Meanwhile, EZH2 is a histone-lysine N-methyltransferase enzyme encoded by gene 7 in humans. Its main function involves catalyzing the addition of methyl groups to histone H3 at lysine 27 (H3K27me3), and it is involved in regulating CD8 + T cell fate and function. It is a subunit of a Polycomb repressor complex 2 (PRC2). The EZH2 gene encodes for an enzyme that is involved in histone methylation and transcriptional repression. It adds methyl groups to lysine 27 on histone H3 (H3K27me3) with the help of the cofactor S-adenosyl-L-methionine. In addition to its role in epigenetic regulation, EZH2 also acts as a regulator of CD8+ T cell fate and function. EZH2 has been implicated in T Cell Receptor (TCR) signaling via the regulation of actin polymerization. In fact, EZH2 is involved in numerous signaling pathways that lead to tumorigenesis. EZH2 is mutated in cancer and shows overexpression. Due to its mutation and overexpression, the cells that help combat cancer are suppressed and carcinogenicity is promoted. The association of EZH2 and YY1 poses an intriguing mechanism in relation to cancer.

Cross-Talks between RKIP and YY1 through a Multilevel Bioinformatics Pan-Cancer Analysis

Recent studies suggest that PEBP1 (also known as RKIP) and YY1, despite having distinct molecular functions, may interact and mutually influence each other's activity. They exhibit reciprocal control over each other's expression through regulatory loops, prompting the hypothesis that their interplay could be pivotal in cancer advancement and resistance to drugs. To delve into this interplay's functional characteristics, we conducted a comprehensive analysis using bioinformatics tools across a range of cancers. Our results confirm the association between elevated YY1 mRNA levels and varying survival outcomes in diverse tumors. Furthermore, we observed differing degrees of inhibitory or activating effects of these two genes in apoptosis, cell cycle, DNA damage, and other cancer pathways, along with correlations between their mRNA expression and immune infiltration. Additionally, YY1/PEBP1 expression and methylation displayed connections with genomic alterations across different cancer types. Notably, we uncovered links between the two genes and different indicators of immunosuppression, such as immune checkpoint blockade response and T-cell dysfunction/exclusion levels, across different patient groups. Overall, our findings underscore the significant role of the interplay between YY1 and PEBP1 in cancer progression, influencing genomic changes, tumor immunity, or the tumor microenvironment. Additionally, these two gene products appear to impact the sensitivity of anticancer drugs, opening new avenues for cancer therapy.

METTL3 facilitates multiple myeloma tumorigenesis by enhancing YY1 stability and pri-microRNA-27 maturation in m6A-dependent manner

Multiple myeloma (MM) is a pernicious plasma cell disorder and has a poor prognosis. N6-methyladenosine (m6A) is an abundant epigenetic RNA modification and is important in cancer progression. Nevertheless, the function of m6A and its regulator METTL3 in MM are rarely reported. Here, we identified the m6A "writers", METTL3, was enhanced in MM and found that Yin Yang 1 (YY1) and primary-miR-27a-3p were the potential target for METTL3. METTL3 promoted primary-miR-27a-3p maturation and YY1 mRNA stability in an m6A manner. YY1 also was found to facilitate miR-27a-3p transcription. METTL3 affected the growth, apoptosis, and stemness of MM cells through accelerating the stability of YY1 mRNA and the maturation of primary-miR-27a-3p in vitro and in vivo. Our results reveal the key function of the METTL3/YY1/miR-27a-3p axis in MM and may provide fresh insights into MM therapy.

Chalcone/1,3,4-Oxadiazole/Benzimidazole hybrids as novel anti-proliferative agents inducing apoptosis and inhibiting EGFR & BRAFV600E

INTRODUCTION

One of the most robust global challenges and difficulties in the 21st century is cancer. Treating cancer is a goal which continues to motivate researchers to innovate in design and development of new treatments to help battle the disease.

OBJECTIVES

Our objective was developing new antiapoptotic hybrids based on biologically active heterocyclic motifs "benzimidazole?oxadiazole-chalcone hybrids'' that had shown promising ability to inhibit EGFR and induce apoptosis. We expected these scaffolds to display anticancer activity via inhibition of BRAF, EGFR, and Bcl-2 and induction of apoptosis through activation of caspases.

METHODS

The new hybrids 7a-x were evaluated for their anti-proliferative, EGFR & BRAFV600E inhibitory, and apoptosis induction activities were detected. Docking study & dynamic stimulation into EGFR and BRAFV600E were studied.

RESULTS

All hybrids exhibited remarkable cell growth inhibition on the four tested cell lines with IC50 ranging from 0.95 μM to 12.50 μM. which was comparable to Doxorubicin. Compounds 7k-m had the most potent EGFR inhibitory activity. While, compounds 7e, 7g, 7k and 7l showed good inhibitory activities against BRAFV600E. Furthermore, Compounds 7k, 7l, and 7m increased Caspases 3,8 & 9, Cytochrome C and Bax levels and decreased Bcl-2 protein levels. Compounds 7k-m received the best binding scores and showed binding modes that were almost identical to each other and comparable with that of the co-crystalized Erlotinib in EGFR and BRAF active sites.

CONCLUSION

Compounds 7k-m could be used as potential apoptotic anti-proliferative agents upon further optimization.

Yin Yang 1-Induced Long Noncoding RNA DUXAP9 Drives the Progression of Oral Squamous Cell Carcinoma by Blocking CDK1-Mediated EZH2 Degradation

LncRNAs play a critical role in oral squamous cell carcinoma (OSCC) progression. However, the function and detailed molecular mechanism of most lncRNAs in OSCC are not fully understood. Here, a novel nuclear-localized lncRNA, DUXAP9 (DUXAP9), that is highly expressed in OSCC is identified. A high level of DUXAP9 is positively associated with lymph node metastasis, poor pathological differentiation, advanced clinical stage, worse overall survival, and worse disease-specific survival in OSCC patients. Overexpression of DUXAP9 significantly promotes OSCC cell proliferation, migration, invasion, and xenograft tumor growth and metastasis, and upregulates N-cadherin, Vimentin, Ki67, PCNA, and EZH2 expression and downregulates E-cadherin in vitro and in vivo, whereas knockdown of DUXAP9 remarkably suppresses OSCC cell proliferation, migration, invasion, and xenograft tumor growth in vitro and in vivo in an EZH2-dependent manner. Yin Yang 1 (YY1) is found to activate the transcriptional expression of DUXAP9 in OSCC. Furthermore, DUXAP9 physically interacts with EZH2 and inhibits EZH2 degradation via the suppression of EZH2 phosphorylation, thereby blocking EZH2 translocation from the nucleus to the cytoplasm. Thus, DUXAP9 can serve as a promising target for OSCC therapy.

YY1 Knockdown Relieves the Differentiation Block and Restores Apoptosis in AML Cells

In this study we analyzed the expression of Yin and Yang 1 protein (YY1), a member of the noncanonical PcG complexes, in AML patient samples and AML cell lines and the effect of YY1 downregulation on the AML differentiation block. Our results show that YY1 is significantly overexpressed in AML patient samples and AML cell lines and that YY1 knockdown relieves the differentiation block. YY1 downregulation in two AML cell lines (HL-60 and OCI-AML3) and one AML patient sample restored the expression of members of the CEBP protein family, increased the expression of extrinsic growth factors/receptors and surface antigenic markers, induced morphological cell characteristics typical of myeloid differentiation, and sensitized cells to retinoic acid treatment and to apoptosis. Overall, our data show that YY1 is not a secondary regulator of myeloid differentiation but that, if overexpressed, it can play a predominant role in myeloid differentiation block.

Targeting Transcription Factor YY1 for Cancer Treatment: Current Strategies and Future Directions

Cancer represents a significant and persistent global health burden, with its impact underscored by its prevalence and devastating consequences. Whereas numerous oncogenes could contribute to cancer development, a group of transcription factors (TFs) are overactive in the majority of tumors. Targeting these TFs may also combat the downstream oncogenes activated by the TFs, making them attractive potential targets for effective antitumor therapeutic strategy. One such TF is yin yang 1 (YY1), which plays crucial roles in the development and progression of various tumors. In preclinical studies, YY1 inhibition has shown efficacy in inhibiting tumor growth, promoting apoptosis, and sensitizing tumor cells to chemotherapy. Recent studies have also revealed the potential of combining YY1 inhibition with immunotherapy for enhanced antitumor effects. However, clinical translation of YY1-targeted therapy still faces challenges in drug specificity and delivery. This review provides an overview of YY1 biology, its role in tumor development and progression, as well as the strategies explored for YY1-targeted therapy, with a focus on their clinical implications, including those using small molecule inhibitors, RNA interference, and gene editing techniques. Finally, we discuss the challenges and current limitations of targeting YY1 and the need for further research in this area.

Tumor progression locus 2 (TPL2): A Cot-plicated progression from inflammation to chronic liver disease

The cytoplasmic protein tumor progression locus 2 (TPL2), also known as cancer Osaka thyroid (Cot), or MAP3K8, is thought to have a significant role in a variety of cancers and illnesses and it is a key component in the activation pathway for the expression of inflammatory mediators. Despite the tight connection between inflammation and TPL2, its function has not been extensively studied in chronic liver disease (CLD), a major cause of morbidity and mortality worldwide. Here, we analyze more in detail the significance of TPL2 in CLD to shed light on the pathological and molecular transduction pattern of TPL2 during the progression of CLD. This might result in important advancements and enable progress in the diagnosis and treatment of CLD.

LINC01608 activated by YY1 facilitate hepatocellular carcinoma progression by modulating the EGFR/ERK axis

BACKGROUND

Long non-coding RNAs (LncRNAs) have been demonstrated to associate with a variety of cancers. However, the mechanisms of LncRNAs in hepatocellular carcinoma (HCC) progression are still not fully clarified.

METHODS

LINC01608 expression level in HCC and adjacent normal tissues was detected by real-time-quantitively PCR (RT-qPCR) in clinical samples and in situ hybridization (ISH) in tissue microarray. Several functional assays were performed to determine the biological effects of LINC01608 in HCC cells in vitro, while subcutaneous xenograft models and lung metastasis models in nude mice and immunohistochemistry (IHC) results showed the role of LINC01608 in HCC progression in vivo. The combination of LINC01608 with miR-875-5p and target genes was elucidated by dual-luciferase report assays, RNA immunoprecipitation (RIP) assays and fluorescence in situ hybridization (FISH) assays. Finally, bioinformatics analysis and chromatin immunoprecipitation (CHIP) were performed to investigate the mechanism of Yin Yang-1 (YY1) regulating LINC01608 transcription.

RESULTS

LINC01608 was overexpressed in HCC tissues, and high LINC01608 expression predicted poor overall survival (OS) and disease-free survival (DFS) in HCC patients. LINC01608 could promote HCC cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Furthermore, we demonstrated that LINC01608 could sponge to miR-875-5p and activate the EGFR/ERK pathway. Moreover, we identified transcriptional factor YY1 could bind to the promoter of LINC01608 and induce its transcription.

CONCLUSION

LINC01608 could serve as a promising prognostic biomarker of HCC. YY1-activated LINC01608 could promote HCC progression by associating with miR-875-5p to induce the EGFR/ERK signalling pathway. This discovery might provide therapeutic strategies for HCC.

Mechanosensitive Ion Channel PIEZO1 Signaling in the Hall-Marks of Cancer: Structure and Functions

Simple Summary

Tumor cells obtain various unique characteristics, which known as hallmarks of cancers, including sustained proliferative signaling, apoptosis resistance, and metastasis. These characteristics are crucial for tumor cells survival and for supporting their rapid growth. Studies have revealed that tumorigenesis is also accompanied by alteration in mechanical properties. Tumor cells could sense various mechanical forces, such as compressive force, shear stress, and portal vein pressure, which in turn could affect tumor progression. Piezo1 is a mechanically sensitive ion channel protein that can be activated mechanically, and is closely related to various diseases. Recent studies showed that Piezo1 is overexpressed in numerous tumors and is associated with poor prognosis. Furthermore, previous studies revealed that Piezo1 mediates these cancer hallmarks, and thus links up mechanical forces with tumor progression. Therefore, the discovery of Piezo1 provides a new insight for elucidating the mechanism of tumor progression under a mechanical microenvironment.

Abstract

Tumor cells alter their characteristics and behaviors during tumorigenesis. These characteristics, known as hallmarks of cancer, are crucial for supporting their rapid growth, need for energy, and adaptation to tumor microenvironment. Tumorigenesis is also accompanied by alteration in mechanical properties. Cells in tumor tissue sense mechanical signals from the tumor microenvironment, which consequently drive the acquisition of hallmarks of cancer, including sustained proliferative signaling, evading growth suppressors, apoptosis resistance, sustained angiogenesis, metastasis, and immune evasion. Piezo-type mechanosensitive ion channel component 1 (Piezo1) is a mechanically sensitive ion channel protein that can be activated mechanically and is closely related to various diseases. Recent studies showed that Piezo1 mediates tumor development through multiple mechanisms, and its overexpression is associated with poor prognosis. Therefore, the discovery of Piezo1, which links-up physical factors with biological properties, provides a new insight for elucidating the mechanism of tumor progression under a mechanical microenvironment, and suggests its potential application as a tumor marker and therapeutic target. In this review, we summarize current knowledge regarding the role of Piezo1 in regulating cancer hallmarks and the underlying molecular mechanisms. Furthermore, we discuss the potential of Piezo1 as an antitumor therapeutic target and the limitations that need to be overcome.

The functions of polycomb group proteins in T cells

T cells are involved in many aspects of adaptive immunity, including autoimmunity, anti-tumor activity, and responses to allergenic substances and pathogens. T cells undergo comprehensive epigenome remodeling in response to signals. Polycomb group (PcG) proteins are a well-studied complex of chromatin regulators, conserved in animals, and function in various biological processes. PcG proteins are divided into two distinct complexes: PRC1 (Polycomb repressive complex 1) and PRC2. PcG is correlated with the regulation of T cell development, phenotypic transformation, and function. In contrast, PcG dysregulation is correlated with pathogenesis of immune-mediated diseases and compromised anti-tumor responses. This review discusses recent findings on the involvement of PcG proteins in T cell maturation, differentiation, and activation. In addition, we explore implications in the development of the immune system diseases and cancer immunity, which offers promising targets for various treatment protocols.

CK2 and the Hallmarks of Cancer

Cancer is a leading cause of death worldwide. Casein kinase 2 (CK2) is commonly dysregulated in cancer, impacting diverse molecular pathways. CK2 is a highly conserved serine/threonine kinase, constitutively active and ubiquitously expressed in eukaryotes. With over 500 known substrates and being estimated to be responsible for up to 10% of the human phosphoproteome, it is of significant importance. A broad spectrum of diverse types of cancer cells has been already shown to rely on disturbed CK2 levels for their survival. The hallmarks of cancer provide a rationale for understanding cancer's common traits. They constitute the maintenance of proliferative signaling, evasion of growth suppressors, resisting cell death, enabling of replicative immortality, induction of angiogenesis, the activation of invasion and metastasis, as well as avoidance of immune destruction and dysregulation of cellular energetics. In this work, we have compiled evidence from the literature suggesting that CK2 modulates all hallmarks of cancer, thereby promoting oncogenesis and operating as a cancer driver by creating a cellular environment favorable to neoplasia.

microRNA-497-mediated Smurf2/YY1/HIF2α axis in tumor growth and metastasis of esophageal squamous cell carcinoma

Aberrant expression of microRNA-497 (miR-497) is associated with tumor progression, but the molecular mechanisms in tumorigenesis remain largely unknown. Here, we report that miR-497 expression is downregulated in esophageal squamous cell carcinoma (ESCC) clinical samples. Consistently, upregulation of miR-497 inhibits ESCC cell malignant properties and tumor growth in vivo. Importantly, we uncovered that miR-497 upregulation suppressed ESCC cell growth and tumor growth by inhibiting Smurf2. Mechanistically, we showed that Smurf2 was a target of miR-497, and mediated YY1 expression to elevate HIF2α expression, thereby enhancing the malignancy of ESCC cells. Together, our study uncovered the role of the miR-497-mediated Smurf2/YY1/HIF2α axis in tumor growth and metastasis, which might provide potential therapeutic targets for human ESCC.

YY1 alleviates lupus nephritis-induced renal injury by reducing the Th17/Treg cell ratio via the IFN-γ/Fra2 axis

Lupus nephritis (LN) is associated with extensive injury and nephron loss in the afflicted kidney. Evidence has revealed the involvement of dysregulated Yin Yang 1 (YY1), a reported inflammatory modulator, in LN-induced kidney injury, and our microarray profile identified downregulated YY1 expression. Therefore, this study explored the functional relevance and mechanism of YY1 in LN-induced kidney injury. LN was modeled in mice by intraperitoneal injection of pristane, and Jurkat cells (CD41 human T lymphocytes) were activated with TNF-α to mimic the inflammatory environment found in LN. The expression patterns of YY1 and bioinformatics predictions of the downstream factor IFN-γ were confirmed in renal tissues from the mice with LN using qRT-PCR and Western blot analyses. The contents of proinflammatory cytokines in mouse serum samples and cell supernatants were determined using enzyme-linked immunosorbent assays (ELISAs). Ectopic expression and depletion approaches were subsequently used in vitro and in vivo to examine the effects of the YY1/IFN-γ/Fra2/PARP-1/FOXO1 axis on TNF-α-induced inflammation and LN-induced kidney injury. The results showed downregulated expression of YY1 and FOXO1 in the kidney tissues of the mice with LN. Increased proinflammatory factor production was observed in the mice with LN and TNF-α-treated Jurkat cell supernatant, accompanied by increased cell apoptosis and a high ratio of Th17/Treg cells, and these effects were reversed by YY1 restoration. YY1 was further shown to inhibit IFN-γ expression and thereby downregulate Fra2 expression. Fra2 depletion then inhibited PARP-1 expression and promoted FOXO1 expression to suppress cell apoptosis and the release of inflammatory factors. Collectively, our findings revealed that YY1 may alleviate LN-induced renal injury via the IFN-γ/Fra2/PARP-1/FOXO1 axis.

The Transcription Factor YY1 Is Essential for Normal DNA Repair and Cell Cycle in Human and Mouse β-Cells

Identifying the mechanisms behind the β-cell adaptation to failure is important to develop strategies to manage type 2 diabetes (T2D). Using db/db mice at early stages of the disease process, we took advantage of unbiased RNA sequencing to identify genes/pathways regulated by insulin resistance in β-cells. We demonstrate herein that islets from 4-week-old nonobese and nondiabetic leptin receptor-deficient db/db mice exhibited downregulation of several genes involved in cell cycle regulation and DNA repair. We identified the transcription factor Yin Yang 1 (YY1) as a common gene between both pathways. The expression of YY1 and its targeted genes was decreased in the db/db islets. We confirmed the reduction in YY1 expression in β-cells from diabetic db/db mice, mice fed a high-fat diet (HFD), and individuals with T2D. Chromatin immunoprecipitation sequencing profiling in EndoC-βH1 cells, a human pancreatic β-cell line, indicated that YY1 binding regions regulate cell cycle control and DNA damage recognition and repair. We then generated mouse models with constitutive and inducible YY1 deficiency in β-cells. YY1-deficient mice developed diabetes early in life due to β-cell loss. β-Cells from these mice exhibited higher DNA damage, cell cycle arrest, and cell death as well as decreased maturation markers. Tamoxifen-induced YY1 deficiency in mature β-cells impaired β-cell function and induced DNA damage. In summary, we identified YY1 as a critical factor for β-cell DNA repair and cell cycle progression.

YY1 Is a Key Player in Melanoma Immunotherapy/Targeted Treatment Resistance

Malignant melanoma, with its increasing incidence and high potential to form metastases, is one of the most aggressive types of skin malignancies responsible for a significant number of deaths worldwide. However, melanoma also demonstrates a high potential for induction of a specific adaptive anti-tumor immune response being one of the most immunogenic malignancies. Yin Yang 1 (YY1) transcription factor is essential to numerous cellular processes and the regulation of transcriptional and posttranslational modifications of various genes. It regulates programmed cell death 1 (PD1) and lymphocyte-activation gene 3 (LAG3) by binding to its promoters, as well as suppresses both Fas and TRAIL by negatively regulating DR5 transcription and expression and interaction with the silencer region of the Fas promoter, rendering cells resistant to apoptosis. Moreover, YY1 is considered a master regulator in various stages of embryogenesis, especially in neural crest stem cells (NCSCs) survival and proliferation as it acts as transcriptional repressor on cancer stem cells-related transcription factors. In addition, YY1 increases the metastatic potential of melanoma through negative regulation of microRNA-9 (miR-9) expression, acts as a cofactor of transcription factor EB (TFEB) and contributes to autophagy regulation, mainly due to increased transcription of genes related to autophagy and lysosome biogenesis. Therefore, focusing on the detailed biology and administration of therapies that directly target YY1 or crosstalk pathways in malignant melanoma could facilitate the development of new and more effective treatment strategies and improve patients’ outcomes.

YY1 Regulates Glucose Homeostasis Through Controlling Insulin Transcription in Pancreatic β-Cells

To date, identification of nonislet-specific transcriptional factors in the regulation of insulin gene expression has been little studied. Here, we report that the expression level of the transcription factor YY1 is increased dramatically in both human and mouse pancreatic β-cells after birth. Nevertheless, the physiological role of YY1 during β-cell development and its regulatory mechanism in β-cell function remain largely unknown. After β-cell ablation of Yy1, we observed rapid onset of hyperglycemia, impaired glucose tolerance, and reduced β-cell mass in neonatal and adult mice. These mice also had hypoinsulinemia with normal insulin sensitivity compared with their wild-type littermates, manifesting as a type 1 diabetic phenotype. Mechanistically, genome-wide RNA sequencing has defined dysregulated insulin signaling and defective glucose responsiveness in β-cells devoid of YY1. Integrative analyses coupled with chromatin immunoprecipitation assays targeting YY1, and histone modifications, including H3K4me1, H3K27ac, and H3K27me3, have further identified Ins1 and Ins2 as direct gene targets of YY1. Luciferase reporter assays and loss- and gain-of-function experiments also demonstrated that YY1 binds to the enhancer regions in exon 2 of Ins1 and Ins2, activating insulin transcription and, therefore, proinsulin and insulin production in pancreatic β-cells. YY1 also directly interacts with RNA polymerase II, potentially stabilizing the enhancer-promoter interaction in the multiprotein-DNA complex during transcription initiation. Taken together, our findings suggest a role for YY1 as a transcriptional activator of insulin gene expression, assisting β-cell maturation and function after birth. These analyses may advance our understanding of β-cell biology and provide clinically relevant insights targeting the pathophysiological origins of diabetes.

Homeostasis Imbalance of YY2 and YY1 Promotes Tumor Growth by Manipulating Ferroptosis

Ferroptosis is a type of programmed cell death caused by disruption of redox homeostasis and is closely linked to amino acid metabolism. Yin Yang 2 (YY2) and its homolog Yin Yang 1 (YY1) are highly homologous, especially in their zinc-finger domains. Furthermore, they share a consensus DNA binding motif. Increasing evidences have demonstrated the tumor suppressive effect of YY2, in contrast with the oncogenic YY1; however, little is known about the biological and pathological functions of YY2. Here, it is determined that YY2 induces tumor cell ferroptosis and subsequently suppresses tumorigenesis by inhibiting solute carrier family 7 member 11 (SLC7A11) transcription, leading to the decreased glutathione biosynthesis. Furthermore, YY2 and YY1 bind competitively to the same DNA binding site in the SLC7A11 promoter and antagonistically regulate tumor cell ferroptosis, thus suggesting the molecular mechanism underlying their opposite regulation on tumorigenesis. Moreover, mutations of YY2 zinc-finger domains in clinical cancer patients abrogate YY2/SLC7A11 axis and tumor cell ferroptosis. Together, these results provide a new insight regarding the regulatory mechanism of ferroptosis, and a mechanistic explanation regarding the tumor suppressive effect of YY2. Finally, these findings demonstrate that homeostasis between YY1 and YY2 is crucial for maintaining redox homeostasis in tumor cells.

YY1 affects the levels and function of fibulin‑5 in ox‑LDL‑treated vascular smooth muscle cells

Fibulin-5 is reportedly involved in the pathological process of atherosclerosis (AS) where low expression has been frequently observed in ruptured atherosclerotic plaques. The aim of the present study was to determine the effects of fibulin-5 on the responses of vascular smooth muscle cells (VSMC) to oxidized low-density lipoprotein (ox-LDL). The expression of fibulin-5 was studied in human aortic-VSMCs (HA-VSMCs) treated with ox-LDL. Fibulin-5 was first overexpressed by the transfection of Ov-Fibulin-5 plasmids in HA-VSMCs challenged with ox-LDL to investigate its influence on cell proliferation, migration and invasion using Cell Counting Kit-8, wound healing and Transwell assays. Yin Yang-1 (YY1) was bioinformatically predicted to bind to the promoter sites of fibulin-5, which was subsequently confirmed by dual-luciferase reporter gene assay. Fibulin-5 overexpression was able to suppress cell proliferation, invasion and migration, which was effectively reversed by YY1 silencing by the transfection of siRNA-Fibulin-5 plasmids which could induced fibulin-5 silencing. YY1 binding sites in the promoter region of fibulin-5 were identified and confirmed in vitro by chromatin immunoprecipitation assay and dual-luciferase reporter gene assay. The present results suggested that as a modulator of fibulin-5, YY1 alleviated ox-LDL-induced proliferation, invasion, migration and phenotypic transition from differentiated contractile phenotype to dedifferentiated phenotype in VSMCs. However, the mechanism underlying the YY1-mediated regulation of fibulin-5 expression needs to be confirmed further in vivo. Nevertheless, targeting fibulin-5 and YY1 could be further developed for AS therapy.

YY1-Targeted RBM15B Promotes Hepatocellular Carcinoma Cell Proliferation and Sorafenib Resistance by Promoting TRAM2 Expression in an m6A-Dependent Manner

As one of the most common internal modifications in eukaryotic mRNA, N6-methyladenosine (m6A) modification is involved in the pathogenesis of many diseases, including hepatocellular carcinoma (HCC). In this study, we explored the prognostic significance of the expression of RNA binding motif protein 15B (RBM15B) in HCC, by studying specimens collected from clinical subjects. RBM15B is highly expressed in HCC patients and indicates a poor prognosis. Functionally, overexpression of RBM15B promotes HCC cell proliferation and invasion and induces sorafenib resistance in HCC cells. Mechanistically, we confirmed that RBM15B is transcriptionally activated by YY1 and regulates the stability of TRAM2 mRNA in an m6A-dependent manner. Overall, our results reveal a YY1-RBM15B-TRAM2 regulatory axis and highlight the critical role of RBM15B and m6A modifications in HCC. These findings may provide a novel mechanism and therapeutic targets for the treatment of HCC.

A histidine cluster determines YY1-compartmentalized coactivators and chromatin elements in phase-separated enhancer clusters

As an oncogenic transcription factor, Yin Yang 1 (YY1) regulates enhancer and promoter connection. However, gaps still exist in understanding how YY1 coordinates coactivators and chromatin enhancer elements to assemble enhancers and super-enhancers. Here, we demonstrate that a histidine cluster in YY1’s transactivation domain is essential for its formation of phase separation condensates, which can be extended to additional proteins. The histidine cluster is also required for YY1-promoted cell proliferation, migration, clonogenicity and tumor growth. YY1-rich nuclear puncta contain coactivators EP300, BRD4, MED1 and active RNA polymerase II, and colocalize with histone markers of gene activation, but not that of repression. Furthermore, YY1 binds to the consensus motifs in the FOXM1 promoter to activate its expression. Wild-type YY1, but not its phase separation defective mutant, connects multiple enhancer elements and the FOXM1 promoter to form an enhancer cluster. Consistently, fluorescent in situ hybridization (FISH) assays reveal the colocalization of YY1 puncta with both the FOXM1 gene locus and its nascent RNA transcript. Overall, this study demonstrates that YY1 activates target gene expression through forming liquid-liquid phase separation condensates to compartmentalize both coactivators and enhancer elements, and the histidine cluster of YY1 plays a determinant role in this regulatory mechanism.

JAC1 targets YY1 mediated JWA/p38 MAPK signaling to inhibit proliferation and induce apoptosis in TNBC

Triple negative breast cancer (TNBC) is a type of breast cancer with poor prognosis, and has no ideal therapeutic target and ideal medicine. Downregulation of JWA is closely related to the poor overall survival in many cancers including TNBC. In this study, we reported at the first time that JWA gene activating compound 1 (JAC1) inhibited the proliferation of TNBC in vitro and in vivo experimental models. JAC1 specifically bound to YY1 and eliminated its transcriptional inhibition of JWA gene. The rescued JWA induced G1 phase arrest and apoptosis in TNBC cells through the p38 MAPK signaling pathway. JAC1 also promoted ubiquitination and degradation of YY1. In addition, JAC1 disrupted the interaction between YY1 and HSF1, and suppressed the oncogenic role of HSF1 in TNBC through p-Akt signaling pathway. In conclusion, JAC1 suppressed the proliferation of TNBC through the JWA/P38 MAPK signaling and YY1/HSF1/p-Akt signaling. JAC1 maybe a potential therapeutic agent for TNBC.

The Non-Specific Lethal (NSL) Histone Acetyltransferase Complex Transcriptionally Regulates Yin Yang 1-Mediated Cell Proliferation in Human Cells

The human males absent on the first (MOF)-containing non-specific lethal (NSL) histone acetyltransferase (HAT) complex acetylates histone H4 at lysine K5, K8, and K16. This complex shares several subunits with other epigenetic regulatory enzymes, which highlights the complexity of its intracellular function. However, the effect of the NSL HAT complex on the genome and target genes in human cells is still unclear. By using a CRISPR/Cas9-mediated NSL3-knockout 293T cell line and chromatin immunoprecipitation-sequencing (ChIP-Seq) approaches, we identified more than 100 genes as NSL HAT transcriptional targets, including several transcription factors, such as Yin Yang 1 (YY1) which are mainly involved in cell proliferation, biological adhesion, and metabolic processes. We found here that the ChIP-Seq peaks of MOF and NSL3 co-localized with H4K16ac, H3K4me2, and H3K4me3 at the transcriptional start site of YY1. In addition, both the mRNA and protein expression levels of YY1 were regulated by silencing or overexpressing NSL HAT. Interestingly, the expression levels of cell division cycle 6, a downstream target gene of YY1, were regulated by MOF or NSL3. In addition, the suppressed clonogenic ability of HepG2 cells caused by siNSL3 was reversed by overexpressing YY1, suggesting the involvement of YY1 in NSL HAT functioning. Additionally, de novo motif analysis of MOF and NSL3 targets indicated that the NSL HAT complex may recognize the specific DNA-binding sites in the promoter region of target genes in order to regulate their transcription.

YY1 Oligomerization Is Regulated by Its OPB Domain and Competes with Its Regulation of Oncoproteins

Simple Summary

YY1 regulates various cancer-related genes and activates key oncoproteins. In this study, we discovered that the oncoprotein binding (OPB) domain of YY1 is both necessary and stimulatory to its oligomerization. The hydrophobic residues, especially F219, in the OPB are essential to YY1 intermolecular interaction. Strikingly, the mutations of the hydrophobic residues showed better ability than wild-type YY1 in promote breast cancer cell proliferation and migration. Our further study revealed that YY1 proteins with mutated hydrophobic residues in the OPB domain showed improved binding affinity to EZH2. Overall, our data support the model of a mutually exclusive process between oligomerization of YY1 and its regulation of the oncoproteins EZH2, AKT and MDM2.

Abstract

Yin Yang 1 (YY1) plays an oncogenic role through regulating the expression of various cancer-related genes and activating key oncoproteins. Previous research reported that YY1 protein formed dimers or oligomers without definite biological implications. In this study, we first demonstrated the oncoprotein binding (OPB) and zinc finger (ZF) domains of YY1 as the regions involved in its intermolecular interactions. ZFs are well-known for protein dimerization, so we focused on the OPB domain. After mutating three hydrophobic residues in the OPB to alanines, we discovered that YY1(F219A) and YY1(3A), three residues simultaneously replaced by alanines, were defective of intermolecular interaction. Meanwhile, the OPB peptide could robustly facilitate YY1 protein oligomerization. When expressed in breast cancer cells with concurrent endogenous YY1 knockdown, YY1(F219A) and (3A) mutants showed better capacity than wt in promoting cell proliferation and migration, while their interactions with EZH2, AKT and MDM2 showed differential alterations, especially with improved EZH2 binding affinity. Our study revealed a crucial role of the OPB domain in facilitating YY1 oligomerization and suggested a mutually exclusive regulation between YY1-mediated enhancer formation and its activities in promoting oncoproteins.

Dual Role of YY1 in HPV Life Cycle and Cervical Cancer Development

Human papillomaviruses (HPVs) are considered to be key etiological agents responsible for the induction and development of cervical cancer. However, it has been suggested that HPV infection alone may not be sufficient to promote cervical carcinogenesis, and other unknown factors might be required to establish the disease. One of the suggested proteins whose deregulation has been linked with oncogenesis is transcription factor Yin Yang 1 (YY1). YY1 is a multifunctional protein that is involved not only in the regulation of gene transcription and protein modification, but can also control important cell signaling pathways, such as cell growth, development, differentiation, and apoptosis. Vital functions of YY1 also indicate that the protein could be involved in tumorigenesis. The overexpression of this protein has been observed in different tumors, and its level has been correlated with poor prognoses of many types of cancers. YY1 can also regulate the transcription of viral genes. It has been documented that YY1 can bind to the HPV long control region and regulate the expression of viral oncogenes E6 and E7; however, its role in the HPV life cycle and cervical cancer development is different. In this review, we explore the role of YY1 in regulating the expression of cellular and viral genes and subsequently investigate how these changes inadvertently contribute toward the development of cervical malignancy.

Multi-Platform-Based Analysis Characterizes Molecular Alterations of the Nucleus in Human Colorectal Cancer

Background: The disturbed molecular alterations of nucleus may promote the development of colorectal cancer (CRC). A multi-platform-based analysis of nucleus of CRC patients helps us to better understand the underlying mechanism of CRC and screen out the potential drug targets for clinical treatment. However, such studies on nucleus in human CRC are still lacking.

Methods: We collected the cancerous and para-cancerous tissues from eight CRC patients and performed a multiplex analysis of the molecular changes of the nucleus, including structural variations (SVs), DNA methylation, chromatin accessibility, proteome and phosphorproteome.

Results: In our study, we revealed a significant molecular change of nucleus of CRC patients using our original proteomic and phosphorylomic datasets. Subsequently, we characterized the molecular alterations of nucleus of CRC patients at multiple dimensionalities, including DNA, mRNA, protein and epigenetic modification. Next, we found that the great molecular changes of nucleus might affect the biological processes named endocytosis and ubiquitin-mediated proteolysis. Besides, we identified DYNC1LI2 and TPR as the potentially hub proteins within the network of nuclear genes in CRC cells. Furthermore, we identified 1905 CRC-specific SVs, and proclaimed 17 CRC-specific SVs were probably associated with the disturbance of immune microenvironment of CRC patients. We also revealed that the SVs of CXCL5, CXCL10 and CXCL11 might be the core SVs among all the immune-relevant SVs. Finally, we identified seven genes as the upstream transcriptional factors potentially regulating the expression of nuclear genes, such as YY1 and JUN, using a multi-omics approach.

Conclusion: Here, we characterized the molecular changes of nucleus of CRC patients, disclosed the potentially core nuclear genes within the network, and identified the probable upstream regulator of nucleus. The findings of this study are helpful to understand the pathogenic molecular changes of nucleus in CRC patients and provide a functional context for drug development in future.