Transcription Factor Yin Yang 1 Research Articles

IL1R2 blockade alleviates immunosuppression and potentiates anti-PD-1 efficacy in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited therapeutic options. Interleukin-1 receptor type 2 (IL1R2) promotes breast tumor-initiating cell (BTIC) self-renewal and tumor growth in TNBC, indicating that targeting it could improve patient treatment. Here, we observed that IL1R2 blockade strongly attenuated macrophage recruitment and the polarization of tumor-associated macrophages (TAMs) to inhibit BTIC self-renewal and CD8+ T cell exhaustion, which resulted in reduced tumor burden and prolonged survival in TNBC mouse models. IL1R2 activation by TAM-derived IL1β increased PD-L1 expression by interacting with the transcription factor yin yang 1 (YY1) and inducing YY1 ubiquitination and proteasomal degradation in both TAMs and TNBC cells. Loss of YY1 alleviated the transcriptional repression of c-Fos, which is a transcriptional activator of PD-L1. Combined treatment with an IL1R2-neutralizing antibody and anti-PD-1 led to enhanced anti-tumor efficacy and reduced TAMs, BTICs, and exhausted CD8+ T cells. These results suggest that IL1R2 blockade might be a strategy to potentiate immune checkpoint blockade efficacy in TNBC to improve patient outcomes.

Role and mechanism of COL3A1 in regulating the growth, metastasis, and drug sensitivity in cisplatin-resistant non-small cell lung cancer cells

ABSTRACT Non-small cell lung cancer (NSCLC) is among the most difficult malignancies to treat. Type III collagen (COL3A1) can affect the progression and chemoresistance development of NSCLC. We herein explored the mechanism that drives COL3A1 dysregulation in NSCLC. Potential RNA-binding proteins (RBPs) and transcription factors (TFs) that could bind to COL3A1 were searched by bioinformatics. mRNA expression was detected by quantitative PCR. Protein expression was evaluated using immunoblotting and immunohistochemistry. The effects of the variables were assessed by gauging cell growth, invasiveness, migratory capacity, apoptosis, and cisplatin (DDP) sensitivity. The direct YY1/COL3A1 relationship was confirmed by ChIP and luciferase reporter experiments. Xenograft experiments were done to examine COL3A1’s function in DDP efficacy. COL3A1 showed enhanced expression in DDP-resistant NSCLC. In H460/DDP and A549/DDP cells, downregulation of COL3A1 exerted inhibitory functions in cell growth, invasiveness, and migration, as well as promoting effects on cell DDP sensitivity and apoptosis. Mechanistically, ELAV-like RNA binding protein 1 (ELAVL1) enhanced the mRNA stability and expression of COL3A1, and Yin Yang 1 (YY1) promoted the transcription and expression of COL3A1. Furthermore, upregulation of COL3A1 reversed ELAVL1 inhibition- or YY1 deficiency-mediated functions in DDP-resistant NSCLC cells. Additionally, COL3A1 downregulation enhanced the anti-tumor efficacy of DDP in vivo. Our investigation demonstrates that COL3A1 upregulation, induced by both RBP ELAVL1 and TF YY1, exerts important functions in phenotypes of NSCLC cells with DDP resistance, offering an innovative opportunity in the treatment of drug-resistant NSCLC.

Silibinin suppresses glioblastoma cell growth, invasion, stemness, and glutamine metabolism by YY1/SLC1A5 pathway.

Silibinin has been found to inhibit glioblastoma (GBM) progression. However, the underlying molecular mechanism by which Silibinin regulates GBM process remains unclear. GBM cell proliferation, apoptosis, invasion, and stemness are assessed by cell counting kit-8 assay, EdU assay, flow cytometry, transwell assay, and sphere formation assay. Western blot is used to measure the protein expression levels of apoptosis-related markers, solute carrier family 1 member 5 (SLC1A5), and Yin Yang-1 (YY1). Glutamine consumption, glutamate production, and α-ketoglutarate production are detected to evaluate glutamine metabolism in cells. Also, SLC1A5 and YY1 mRNA levels are examined using quantitative real-time PCR. Chromatin immunoprecipitation assay and dual-luciferase reporter assay are used to detect the interaction between YY1 and SLC1A5. Mice xenograft models are constructed to explore Silibinin roles in vivo. Silibinin inhibits GBM cell proliferation, invasion, stemness, and glutamine metabolism, while promotes apoptosis. SLC1A5 is upregulated in GBM and its expression is decreased by Silibinin. SLC1A5 overexpression abolishes the anti-tumor effect of Silibinin in GBM cells. Transcription factor YY1 binds to SLC1A5 promoter region to induce SLC1A5 expression, and the inhibition effect of YY1 knockdown on GBM cell growth, invasion, stemness, and glutamine metabolism can be reversed by SLC1A5 overexpression. In addition, Silibinin reduces GBM tumor growth by regulating YY1/SLC1A5 pathway. Silibinin plays an anti-tumor role in GBM process, which may be achieved via inhibiting YY1/SLC1A5 pathway.

Transcription factor YY1 accelerates hepatic fibrosis development by activating NLRP3 inflammasome-mediated pyroptosis.

Hepatic fibrosis is the basis of multiple liver diseases and may eventually develop into hepatocellular carcinoma. Hepatic stellate cell (HSC) activation is a driving factor of hepatic fibrogenesis. In the liver microenvironment, liver cells and others play a crucial role in HSC activation. The liver tissues of CCl4-induced rats show excessive fibrosis, inflammation, and cell apoptosis. Yin Yang 1 (YY1) was highly expressed in hepatic fibrosis rats and TGF-β1-treated liver cells. In animal experiments, YY1 knockdown effectively attenuated CCl4-induced liver injury and pyroptosis-related IL-1β and IL-18 expression. In cellular experiments, NLRP3 inflammasome-mediated pyroptosis was activated by TGF-β1 treatment, while YY1 knockdown significantly inhibited the activation of the NLRP3 inflammasome, pyroptosis, and the secretion of IL-1β and IL-18. In addition, our data showed that TGF-β1-treated liver cell conditional medium markedly induced HSC activation, which was rescued by YY1 knockdown in liver cells. YY1 overexpression in liver cells contributed to the activation of TGF-β1-treated liver cell conditional medium in HSCs, however, this effect of YY1 was attenuated by NLRP3 inhibition. Overall, YY1 overexpression in liver cells contributed to HSC activation by facilitating IL-1β and IL-18 production via activating NLRP3 inflammasome-mediated pyroptosis, thus aggravating hepatic fibrogenesis. Our data indicate that YY1 may be a novel target for the treatment of hepatic fibrosis and associated liver diseases.

Yin Yang 1 suppresses apoptosis and oxidative stress injury in SH-SY5Y cells by facilitating NR4A1 expression

Oxidative stress plays a significant role in the development of Parkinson’s disease (PD). Previous studies implicate nuclear receptor subfamily 4 group A member 1 (NR4A1) in oxidative stress associated with PD. However, the molecular mechanism underlying the regulation of NR4A1 expression remains incompletely understood. In the present study, a PD cell model was established by using 1-methyl-4-phenylpyridinium (MPP+) in SH-SY5Y cells. Cell viability and apoptosis were assessed by using CCK-8 assay and flow cytometry, respectively. The activities of LDH and SOD, and ROS generation were used as an indicators of oxidative stress. ChIP-PCR was performed to detect the interaction between Yin Yang 1 (YY1) and the NR4A1 promoter. MPP+ treatment inhibited SH-SY5Y cell viability in a dose- and time-dependent manner. NR4A1 and YY1 expression were decreased in MPP+-treated SH-SY5Y cells. Increasing NR4A1 or YY1 alleviated MPP+-induced apoptosis and oxidative stress in SH-SY5Y cells, whereas reduction of NR4A1 aggravated MPP+-induced cell injury. Transcription factor YY1 facilitated NR4A1 expression by binding with NR4A1 promoter. In addition, in MPP+-treated SH-SY5Y cells, the inhibition of NR4A1 to apoptosis and oxidative stress was further enhanced by overexpression of YY1. The reduction of NR4A1 led to an elevation of apoptosis and oxidative stress in MPP+-induced SH-SY5Y cells, and this effect was partially reversed by the overexpression of YY1. In conclusion, YY1 suppresses MPP+-induced apoptosis and oxidative stress in SH-SY5Y cells by binding with NR4A1 promoter and boosting NR4A1 expression. Our findings suggest that NR4A1 may be a candidate target for PD treatment. HIGHLIGHTS NR4A1 and YY1 are decreased in MPP+-treated SH-SY5Y cells. NR4A1 prevents oxidative stress and apoptosis in MPP+-treated SH-SY5Y cells. YY1 binds with NR4A1 promoter and increases NR4A1 expression. YY1 enhances the inhibition of NR4A1 to SH-SY5Y cell apoptosis and oxidative stress.

Regulation of TREM2 expression by transcription factor YY1 and its protective effect against Alzheimer’s disease

TREM2 encoding the transmembrane receptor protein TREM2 is a risk gene of Alzheimer's disease (AD), and the impairment of TREM2 functions in microglia due to mutations in TREM2 may significantly increase the risk of AD by promoting AD pathologies. However, how the expression of TREM2 is regulated and the transcription factors required for TREM2 expression are largely unknown. By luciferase assay, DNA pull-down, and in silico predictions, we identified Yin Yang 1(YY1) as a binding protein of the minimal promoter of the TREM2 gene, and the binding was further confirmed by EMSA and DNA pull-down assay. shRNA-mediated YY1 silencing significantly reduced the activity of the TREM2 minimal promoter and TREM2 protein levels in the microglial cell line BV2 and the neuroblastoma Neuro2A. Furthermore, we found that the levels of TREM2 and YY1 were both downregulated in lipopolysaccharide-treated BV2 cells and in the brain of AD model mice. These results demonstrated that YY1 plays a crucial role in the regulation of TREM2 expression. Our study suggests that microglial YY1 could be targeted to maintain TREM2 expression for AD prevention and therapy.

The role of transcription factor Yin Yang-1 in colorectal cancer.

Yin Yang-1 (YY1) is identified as a transcription factor with multiple functions. However, the role of YY1 in tumorigenesis remains controversial and its regulatory effects may depend upon not only cancer types, but also its interacting partners, chromatin structure, and the context in which it acts. It has been detected that YY1 was highly expressed in colorectal cancer (CRC). Intriguingly, many YY1-repressed genes exhibit tumor suppressive potential while YY1 silencing is related to chemotherapy resistance. Therefore, it is crucial to meticulously explore YY1 protein structure and the dynamic alteration of its interactome in each cancer type. This review attempts to describe the structure of YY1, summarize the mechanism that influence the expression level of YY1 and also highlight the recent advances in our understanding of regulatory insights of YY1 functions in CRC. Related studies were identified through scoping search of PubMed, Web of science, Scopus and Emhase concerning the terms of "colorectal cancer", colorectal carcinoma" or CRC with "YY1". The retrieval strategy included title, abstract, and keywords with no language limitations. All the included articles were categorized depending on the mechanisms they explored. In total, 170 articles were identified for further screening. After removing the duplication, not relevant outcomes and review articles, 34 were finally included in the review. Among them, 10 articles revealed the reasons of YY1 high expression in CRC, 13 articles explored YY1 function in CRC, and 11 articles fell into both aspects. In addition, we also summarized 10 clinical trials concerning the expression and activity of YY1 in various diseases, which offers a hint for future application. YY1 is highly expressed in CRC and broadly recognized as an oncogenic factor during the whole course of CRC. Sporadic controversial views are raised in term of CRC treatment, reminding us that future studies should take the influence of therapeutic regimens into concern.

Transcription factor YY1 mediates self-renewal of glioblastoma stem cells through regulation of the SENP1/METTL3/MYC axis.

Glioma is a primary brain tumor with limited treatment approaches and glioblastoma stem cells (GSCs) are manifested with the self-renewal capability and high tumorigenic capacity. This study was performed to investigate the regulatory effect of the SUMO-specific protease 1 (SENP1)/methyltransferase-like 3 (METTL3)/MYC axis on the self-renewal of GSCs mediated by transcription factor Yin Yang 1 (YY1). Following bioinformatics analysis and clinical and cellular experiments, we found that YY1 was highly expressed in GBM tissues and cells, while silencing its expression reduced the self-renewal ability of GSCs. Functionally, YY1 promoted the transcriptional expression of SENP1 by binding to the promoter region of SENP1, while the deSUMOase SENP1 facilitated the methylase activity of m6A through deSUMOylation of the methylase METTL3, thereby promoting the m6A modification of MYC mRNA via METL3 and promoting the expression of MYC. A nude mouse xenograft model of GBM was also constructed to examine the tumorigenicity of GSCs. The obtained findings demonstrated that YY1 promoted tumorigenicity of GSCs by promoting the expression of MYC in vivo. Conclusively, YY1 can transcriptionally upregulate the SUMOylase SENP1 and enhance the methylase activity of METTL3, resulting in the increased m6A modification level of MYC mRNA, thereby promoting the self-renewal of GSCs.

Zinc controls operator affinity of human transcription factor YY1 by mediating dimerization via its N-terminal region

Human protein Yin Yang 1 (YY1) controls the transcription of hundreds of genes both positively and negatively through interactions with a wide range of partner proteins. Results presented here from proteolytic sensitivity, calorimetry, circular dichroism, fluorescence, NMR, size-exclusion chromatography, SELEX, and EMSA show that purified YY1 forms dimers via its disordered N-terminal region with strong zinc-ion concentration dependence. The YY1 dimer is shown to bind tandem repeats of a canonical recognition DNA sequence with high affinity, and analysis of human YY1 regulatory sites shows that many contain repeats of its recognition elements. YY1 dimerization may compete with partner protein interactions, making control by zinc ion concentration a previously unrecognized factor affecting YY1 gene regulation. Indeed, YY1 is known to be important in many pathogenic processes, including neoplasia, in which zinc ion concentrations are altered. The present results incentivize studies in vivo or in vitro that explore the role of zinc ion concentration in YY1-mediated gene expression.

PLAU is associated with cell migration and invasion and is regulated by transcription factor YY1 in cervical cancer.

Cervical cancer, one of the most common malignancies, has a poor survival rate. The identification of more biomarkers for cervical cancer diagnosis and therapy is urgently needed. Plasminogen activator urokinase (PLAU) exerts multiple biological effects in various physiological and pathological processes; however the role of PLAU in cervical cancer progression is not fully understood. In the present study, the involvement and transcriptional regulation of PLAU in cervical cancer were explored. The expression of PLAU in cervical cancer was first analyzed, and PLAU was found to be overexpressed. Invitro experiments demonstrated that the migration and invasion of HeLa and HT3 cells were significantly suppressed by PLAU knockdown. Additionally, the core promoter of PLAU was confirmed, and the transcription factor YinYang 1 (YY1) was found to regulate PLAU mRNA expression. Overall, the present study elucidated the direct association between PLAU and cervical cancer, suggesting the YY1/PLAU axis as a potential novel therapeutic target for cervical cancer.

YY1 transcription factor induces proliferation and aerobic glycolysis of neuroblastoma cells via LDHA regulation.

The present study investigated the effect of transcription factor yin yang 1 (YY1) on aerobic glycolysis and cell proliferation in neuroblastoma and its mechanism. Neuroblastoma cell lines were used to investigate the association between YY1 and lactate dehydrogenase A (LDHA) expression. Cell Counting Kit (CCK)-8 and clone formation experiments were used to detect the cell viability. The interaction of YY1 and LDHA was detected using chromatin immunoprecipitation assay. Glucose uptake, intra/extracellular lactate and pyruvate and LDHA expression were evaluated using standard methods. Reverse transcription quantitative PCR, western blotting and gene overexpression or silencing were undertaken to explore the biological effects and underlying mechanisms of transcriptional regulators in NB cells. The results demonstrated that YY1 was significantly upregulated in neuroblastoma cell lines. The results of aerobic glycolysis and CCK-8 indicated that YY1 significantly promoted the proliferation and aerobic glycolysis of neuroblastoma cells. In addition, chromatin immunoprecipitation-PCR results demonstrated that YY1 was directly bound to the promoter LDHA. Overexpression of LDHA could reverse the inhibitory effect of sh-YY1 on aerobic glycolysis and proliferation of neuroblastoma cells. In conclusion, YY1 could induce aerobic glycolysis and proliferation of neuroblastoma cell lines, and may directly mediate the regulation of LDHA. These findings may provide novel insight for the treatment of neuroblastoma.

Knockdown of YY1 Inhibits XIST Expression and Enhances Cloned Pig Embryo Development.

The technique of cloning has wide applications in animal husbandry and human biomedicine. However, the very low developmental efficiency of cloned embryos limits the application of cloning. Ectopic XIST-expression-induced abnormal X chromosome inactivation (XCI) is a primary cause of the low developmental competence of cloned mouse and pig embryos. Knockout or knockdown of XIST improves cloning efficiency in both pigs and mice. The transcription factor Yin yang 1(YY1) plays a critical role in XCI by triggering the transcription of X-inactive specific transcript (XIST) and facilitating the localization of XIST RNA on the X chromosome. This study aimed to investigate whether RNA interference to suppress the expression of YY1 can inhibit erroneous XIST expression, rescue abnormal XCI, and improve the developmental ability of cloned pig embryos. The results showed that YY1 binds to the 5' regulatory region of the porcine XIST gene in pig cells. The microinjection of YY1 siRNA into cloned pig embryos reduced the transcript abundance of XIST and upregulated the mRNA level of X-linked genes at the 4-cell and blastocyst stages. The siRNA-mediated knockdown of YY1 altered the transcriptome and enhanced the in vitro and in vivo developmental efficiency of cloned porcine embryos. These results suggested that YY1 participates in regulating XIST expression and XCI in cloned pig embryos and that the suppression of YY1 expression can increase the developmental rate of cloned pig embryos. The present study established a new method for improving the efficiency of pig cloning.

Suppressive effect of YY1-mediated RGS22 regulation on the proliferation, migration and invasion of pancreatic ductal adenocarcinoma.

Regulator of G-protein signaling 22 (RGS22) is specifically expressed in the testis and in tumors of epithelial origin, but the expression and role of RGS22 in pancreatic cancer are unclear. In this study, 52 pairs of pancreatic ductal adenocarcinoma (PDAC) and adjacent non-neoplastic tissue samples with the corresponding clinical data were used to examine the expression of RGS22 and its relationship with PDAC prognosis. The findings showed that the expression of RGS22 was higher in the PDAC tissues than in the adjacent non-tumorous tissues and its expression was associated with the degree of blood vessel invasion. The in vitro experiments with PDAC cell lines and a normal control cell line showed that the proliferation, invasion, and metastasis of PDAC cells were suppressed by RGS22 overexpression and enhanced by RGS22 knockdown. The in vivo effect of RGS22 on PDAC xenografts was studied using subcutaneous implantation of tumor cells in BALB/cA-nu mice, and the results corroborated the in vitro findings. Analysis of the regulators of RGS22 showed that it was positively regulated by the transcription factor Yin Yang-1 (YY1). Thus, YY1-mediated RGS22 regulation suppressed the proliferation, migration, and invasion of PDAC.

HISTONE DEACETYLASE 9 transduces heat signal in plant cells

Heat stress limits plant growth, development, and crop yield, but how plant cells precisely sense and transduce heat stress signals remains elusive. Here, we identified a conserved heat stress response mechanism to elucidate how heat stress signal is transmitted from the cytoplasm into the nucleus for epigenetic modifiers. We demonstrate that HISTONE DEACETYLASE 9 (HDA9) transduces heat signals from the cytoplasm to the nucleus to play a positive regulatory role in heat responses in Arabidopsis. Heat specifically induces HDA9 accumulation in the nucleus. Under heat stress, the phosphatase PP2AB'β directly interacts with and dephosphorylates HDA9 to protect HDA9 from 26S proteasome-mediated degradation, leading to the translocation of nonphosphorylated HDA9 to the nucleus. This heat-induced enrichment of HDA9 in the nucleus depends on the nucleoporin HOS1. In the nucleus, HDA9 binds and deacetylates the target genes related to signaling transduction and plant development to repress gene expression in a transcription factor YIN YANG 1-dependent and -independent manner, resulting in rebalance of plant development and heat response. Therefore, we uncover an HDA9-mediated positive regulatory module in the heat shock signal transduction pathway. More important, this cytoplasm-to-nucleus translocation of HDA9 in response to heat stress is conserved in wheat and rice, which confers the mechanism significant implication potential for crop breeding to cope with global climate warming.

Transcription Factor YY1 Ameliorates Liver Ischemia-reperfusion Injury Through Modulating the miR-181a-5p/ESR1/ERBB2 Axis.

Liver ischemia/reperfusion injury (I/RI) is characterized by inflammatory actions. Understanding the mechanistic insights underpinning inflammation is critical to developing treatment strategies. In this study, we illustrated the mechanistic insights of transcription factor Yin-Yang 1 (YY1)-mediated microRNA (miR)-181a-5p/estrogen receptor alpha (ESR1)/epidermal growth factor receptor 2 (ERBB2) axis in liver I/RI. First, we established liver I/RI models in mice and hypoxia-reperfusion (H/R) cell models in mouse hepatocytes (AML12). Subsequently, the expression of YY1, miR-181a-5p, and ESR1 was determined in the 2 models. I/RI mouse models were further injected with lentivirus carrying oe-YY1' and H/R-exposed AML12 cells were subjected to a series of inhibitors, mimics, and shRNAs to validate the mechanisms of YY1 in controlling miR-181a-5p and ESR1 in liver I/RI. Upregulated expression of miR-181a-5p and downregulated expression of YY1 were identified in the liver tissues of liver I/RI mice and H/R-exposed hepatocytes. Moreover, overexpression of YY1 inhibited the miR-181a-5p expression and thus repressed the H/R-induced hepatocyte apoptosis and inflammation. ESR1 was further validated as a target gene of miR-181a-5p and could be negatively regulated by miR-181a-5p. miR-181a-5p inhibition elevated ESR1 expression, which consequently enhanced the ERBB2 expression and reduced H/R-induced hepatocyte apoptosis and inflammation. Overall, these findings highlighted that YY1 repressed the miR-181a-5p expression and stimulated ESR1-mediated activation of ERBB2, thereby ameliorating liver I/RI. This study provides insight into the development of novel targets for liver I/RI.

The Transcription Factor YY-1 Is an Essential Regulator of T Follicular Helper Cell Differentiation.

T follicular helper (TFH) cells are a specialized subset of CD4 T cells that deliver critical help signals to B cells for the production of high-affinity Abs. Understanding the genetic program regulating TFH differentiation is critical if one wants to manipulate TFH cells during vaccination. A large number of transcription factor (TFs) involved in the regulation of TFH differentiation have been characterized. However, there are likely additional unknown TFs required for this process. To identify new TFs, we screened a large short hairpin RNA library targeting 353 TFs in mice using an in vivo RNA interference screen. Yin Yang 1 (YY-1) was identified as a novel positive regulator of TFH differentiation. Ablation of YY-1 severely impaired TFH differentiation following acute viral infection and protein immunization. We found that the zinc fingers of YY-1 are critical to support TFH differentiation. Thus, we discovered a novel TF involved in the regulation of TFH cells.

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.

Inhibition of NLRC5 attenuates the malignant growth and enhances the sensitivity of gastric cancer cells to 5-FU chemotherapy by blocking the carcinogenic effect of YY1.

Gastric cancer (GC) is one of the commonest malignant tumors of the digestive system, characterized by high morbidity and mortality rates. It has been reported that NOD like receptor (NLR) family, CARD domain containing 5 (NLRC5) serves an important role in the occurrence and development of GC. Therefore, the current study aimed to investigate the role of NLRC5 in GC. The mRNA and protein expression levels of NLRC5 in GC cell lines were determined by reverse transcription-quantitative PCR and western blot analysis, respectively. Additionally, following NLRC5 knockdown, cell proliferation, invasion and migration were evaluated using Cell Counting Kit 8, colony formation, wound healing and Transwell assays, and western blot analysis. The NLRC and Yin Yang 1 (YY1) expression in the AGS cells with 5-FU resistance were detected by western blotting. The sensitivity of GC cells to 5-fluorouracil (5-FU) was detected by flow cytometry and western blot analysis. Additionally, the binding capacity of YY1 on NLRC5 promoter was predicted using JASPAR database and it was further verified by chromatin immunoprecipitation and luciferase reporter assays. Finally, to elucidate the mechanism underlying the effect of NLRC5 on GC, YY1 was overexpressed and NLRC5 was silenced in GC cell lines. The results showed that NLRC5 was abnormally upregulated in GC cells. In addition, NLRC5 knockdown significantly attenuated the proliferation, invasion and migration abilities of GC cells, while it enhanced the sensitivity of GC cells to 5-FU. The above effects were regulated by the YY1 transcription factor. Overall, the results of the present study indicated that NLRC5 silencing could reduce the malignant growth and enhance the sensitivity of GC cells to 5-FU chemotherapy via inhibiting the carcinogenic effect of YY1.

YY1/ITGA3 pathway may affect trophoblastic cells migration and invasion ability

Recurrent spontaneous abortion (RSA) is a disturbing pregnancy disorder experienced by ~2.5% of women attempting to conceive. The pathogenesis of RSA is still unclear. Previous findings revealed that transcription factor YIN-YANG 1(YY1) was related to the pathogenesis of RSA by influence trophoblastic cell invasion ability. Present study aimed to investigate more specific molecular mechanism of YY1 playing in trophoblastic cells. In our research, RNA-seq and Chip-seq were used to find significant changed genes between si-YY1(Knock down of YY1) HTR-8/SVneo cells(n = 3) and HTR-8/SVneo cells(n = 3). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis results suggested that Integrins related pathway maybe necessary to biological functions of trophoblastic cells. Chip-seq dataset analysis results predict YY1 can regulate ITGA3/7 expression by binding to the promoter region of ITGA3/7. Furthermore, results from chip experiment, RT-PCR, Dual-luciferase reporter gene assay showed that YY1 was able to bind to the promoter region of ITGA3 and regulate ITGA3 mRNA and protein expression. However, ITGA7 could not be significant influenced by YY1. Besides, gene silencing experiment, Western blot and Immunofluorescence assay confirmed that both YY1 and ITGA3 can accelerate phosphorylation focal adhesion kinase and affect cytoskeleton formation in HTR-8/SVneo cells. In conclusion, YY1/ITGA3 play a critical role in trophoblast invasion ability by regulating cytoskeleton formation.

Long non-coding RNA SNHG5 promotes the osteogenic differentiation of bone marrow mesenchymal stem cells via the miR-212-3p/GDF5/SMAD pathway

BackgroundThe treatment of bone loss has posed a challenge to clinicians for decades. Thus, it is of great significance to identify more effective methods for bone regeneration. However, the role and mechanisms of long non-coding RNA small nucleolar RNA host gene 5 (SNHG5) during osteogenic differentiation remain unclear.MethodsWe investigated the function of SNHG5, Yin Yang 1 (YY1), miR-212-3p and growth differentiation factor 5 (GDF5) in osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) in vitro and in vivo. Molecular mechanisms were clarified by chromatin immunoprecipitation assay and dual luciferase reporter assay.ResultsWe found SNHG5 expression was upregulated during osteogenesis of hBMSCs. Knockdown of SNHG5 in hBMSCs inhibited osteogenic differentiation while overexpression of SNHG5 promoted osteogenesis. Moreover, YY1 transcription factor directly bound to the promoter region of SNHG5 and regulated SNHG5 expression to promote osteogenesis. Dual luciferase reporter assay confirmed that SNHG5 acted as a miR-212-3p sponge and miR-212-3p directly targeted GDF5 and further activated Smad1/5/8 phosphorylation. miR-212-3p inhibited osteogenic differentiation, while GDF5 promoted osteogenic differentiation of hBMSCs. In addition, calvarial defect experiments showed knockdown of SNHG5 and GDF5 inhibited new bone formation in vivo.ConclusionOur results demonstrated that the novel pathway YY1/SNHG5/miR-212-3p/GDF5/Smad regulates osteogenic differentiation of hBMSCs and may serve as a potential target for the treatment of bone loss.