EZH2 Knockdown Research Articles

EZH2 is essential for spindle assembly regulation and chromosomal integrity during porcine oocyte meiotic maturation†.

Enhancer of zeste homolog 2 (EZH2) has been extensively investigated to participate in diverse biological processes, including carcinogenesis, the cell cycle, X-chromosome inactivation, and early embryonic development. However, the functions of this protein during mammalian oocyte meiotic maturation remain largely unexplored. Here, combined with RNA-Seq, we provided evidence that EZH2 is essential for oocyte meiotic maturation in pigs. First, EZH2 protein expression increased with oocyte progression from GV to MII stage. Second, the siRNA-mediated depletion of EZH2 led to accelerated GVBD and early occurrence of the first polar body extrusion. Third, EZH2 knockdown resulted in defective spindle assembly, abnormal SAC activity, and unstable K-MT attachment, which was concomitant with the increased rate of aneuploidy. Finally, EZH2 silencing exacerbated oxidative stress by increasing ROS levels and disrupting the distribution of active mitochondria in porcine oocytes. Furthermore, parthenogenetic embryonic development was impaired following the depletion of EZH2 at GV stage. Taken together, we concluded that EZH2 is necessary for porcine oocyte meiotic progression through regulating spindle organization, maintaining chromosomal integrity, and mitochondrial function.

Downregulation of histone‑lysine N‑methyltransferase EZH2 inhibits cell viability and enhances chemosensitivity in lung cancer cells

Histone-lysine N-methyltransferase EZH2 (EZH2) is the principle component of the polycomb repressive complex 2 (PRC2)/embryonic ectoderm development protein-EZH2 complex, which promotes tumorigenesis by repressing transcription of tumor suppressor genes. EZH2 is considered a key marker in several types of cancer, such as colorectal and prostate cancer. However, the molecular mechanisms and clinical value of EZH2 in lung cancer have not yet been fully investigated. The aim of the present study was to investigate the functions of EZH2 in lung cancer progression and to determine whether treatment with an EZH2 inhibitor enhanced the chemosensitivity of lung cancer cells to cisplatin (CDDP). At the logarithmic growth phase, A549 cells were treated with a small interfering (si)RNA-EZH2, and cell viability was detected using an MTT assay. The degree of apoptosis and cell cycle were detected using flow cytometry. Cell migration and invasion were detected via wound healing and Transwell Matrigel assays. According to information from the Gene Expression Omnibus database, the results of the present study demonstrated that EZH2 was upregulated in lung cancer. Furthermore, overexpression of EZH2 was associated with poor patient prognosis, while EZH2 knockdown inhibited cell viability and migration, and enhanced apoptosis and chemosensitivity in a lung cancer cell line. EZH2 knockdown and treatment of A549 cells using EZH2 inhibitor elevated the inhibitory effects of CDDP on cell viability and apoptosis. Western blot and reverse transcription-quantitative PCR analyses were performed to assess the expression levels of relative protein and mRNA, respectively, in A549 cells treated with siRNA-EZH2 or with CDDP. Overall, the results of the present study demonstrated that high EZH2 expression was associated with poor prognosis, accompanied with a potential impairment of migration and viability in lung cancer cells. These findings suggest that EZH2 may act as a candidate molecular target for gene therapy, and treatment with EZH2 inhibitor may be used to increase chemosensitivity to CDDP agents in lung cancer.

EZH2-dependent epigenetic modulation of histone H3 lysine-27 contributes to psoriasis by promoting keratinocyte proliferation

Psoriasis is characterized by keratinocyte hyperproliferation. While significant progress has been made in understanding the molecular mechanism regulating the proliferation of keratinocytes, little is known about the epigenetic factors that control this process. EZH2 and EZH2 mediated trimethylation of histone H3 lysine 27 (H3K27me3) was previously shown ectopically expressed in carcinoma and mediated proliferation, thereby we sought to clarify the role of EZH2–H3K27me3 in the proliferation of psoriatic keratinocyte. Interestingly, we found that EZH2 and H3K27me3 were both overexpressed in the epidermis of psoriatic lesional skin compared to normal skin. In vitro, the expression of EZH2 and H3K27me3 was stimulated in human keratinocytes treated with mixture of psoriasis-related cytokines pool (TNF-α, IFN-γ, IL-17A, and IL-22). Knockdown of EZH2 significantly reduced keratinocyte proliferative activity. Results from mRNA microarray analysis suggested that Kallikrein-8 (KLK8) might be the target gene of EZH2 in psoriatic keratinocytes. Overexpression or knockdown KLK8 could partially reverse the abnormal proliferation of keratinocytes caused by knockdown or overexpression of EZH2. In vivo, the inhibitor of EZH2, GSK126 could ameliorate the imiquimod-induced psoriasiform lesion. These results suggest that EZH2 might be a therapeutic target for the treatment of psoriasis.

EZH2 knockdown in tamoxifen-resistant MCF-7 cells unravels novel targets for regaining sensitivity towards tamoxifen.

Acquired resistance to drug involves multilayered genetic and epigenetic regulation. Inhibition of EZH2 has proven to reverse the tamoxifen resistance back to the sensitive state in breast cancer. However, the molecular players involved in EZH2-mediated effects on tamoxifen-resistant MCF-7 cells are unknown. This study was conducted to understand the global change in proteome profile of tamoxifen-resistant MCF-7 breast cancer cells upon EZH2 knockdown. Tamoxifen resistance MCF-7 breast cancer cells were established using increasing concentrations of 4-hydroxy tamoxifen. Using label free proteomics approach, we studied the alteration in total proteome in resistant cells as well as cells transfected with siEZH2 in comparison to sensitive and cells transfected with non-targeting siRNA. Here, we report list of proteins that were previously not recognized for their role in tamoxifen resistance and hold a close association with breast cancer patient survival. Proteins Annexin A2, CD44, nucleosome assembly protein 1, and lamin A/C were among the most upregulated protein in tamoxifen-resistant cells that were found to be abrogated upon EZH2 knockdown. The study suggests the involvement for various proteins in acquiring resistance towards tamoxifen and anticipates further research for investigating their therapeutic potentials. Overall, we propose that targeting EZH2 or the molecules down the cascade might be helpful in reacquiring sensitivity to tamoxifen in breast cancer.

Loss of histone lysine methyltransferase EZH2 confers resistance to tyrosine kinase inhibitors in non-small cell lung cancer.

Tyrosine kinase inhibitor (TKI) treatment is the first-line therapy for non-small cell lung cancer (NSCLC) caused by activating mutations of epidermal growth factor receptor (EGFR). However, acquired resistance to EGFR-TKI occurs almost inevitably. Aberrant activation of proto-oncogene MET has been known to confer EGFR-TKI resistance; however, the mechanisms involved remains unclear. Recent evidence implicates epigenetic heterogeneity as playing roles in cancer drug resistance, whereas links involving epigenetic heterogeneity and MET in NSCLC remain poorly understood. We found that expression of EZH2, a histone methyltransferase, was negatively correlated with MET activation and EGFR-TKI resistance in NSCLC cells and clinical samples, suggesting the potential for EZH2 to be used as a biomarker for EGFR-TKI sensitivity. Knockdown or inhibition of EZH2 up-regulated MET expression and phosphorylation, and elevated proliferation and EGFR-TKI resistance of cells in vitro. Meanwhile, inhibition of MET or PI3K/AKT enhanced EZH2 levels and restored sensitivity to EGFR-TKI. These findings indicate a "MET-AKT-EZH2" feedback loop regulating EGFR-TKI-resistance. Furthermore, combination therapy of PI3K/AKT inhibition and EGFR-TKI, which interrupts the loop, enhanced tumor-suppressive effects in an EGFR-TKI-resistant xenograft model, indicating a potential approach against drug resistance in NSCLC.

Salinomycin inhibits epigenetic modulator EZH2 to enhance death receptors in colon cancer stem cells

ABSTRACT Drug resistance is one of the trademark features of Cancer Stem Cells (CSCs). We and others have recently shown that paucity of functional death receptors (DR4/5) on the cell surface of tumour cells is one of the major reasons for drug resistance, but their involvement in the context of in CSCs is poorly understood. By harnessing CSC specific cytotoxic function of salinomycin, we discovered a critical role of epigenetic modulator EZH2 in regulating the expression of DRs in colon CSCs. Our unbiased proteome profiler array approach followed by ChIP analysis of salinomycin treated cells indicated that the expression of DRs, especially DR4 is epigenetically repressed in colon CSCs. Concurrently, EZH2 knockdown demonstrated increased expression of DR4/DR5, significant reduction of CSC phenotypes such as spheroid formation in-vitro and tumorigenic potential in-vivo in colon cancer. TCGA data analysis of human colon cancer clinical samples shows strong inverse correlation between EZH2 and DR4. Taken together, this study provides an insight about epigenetic regulation of DR4 in colon CSCs and advocates that drug-resistant colon cancer can be therapeutically targeted by combining TRAIL and small molecule EZH2 inhibitors.

Leishmania donovani Subverts Host Immune Response by Epigenetic Reprogramming of Macrophage M(Lipopolysaccharides + IFN-γ)/M(IL-10) Polarization.

Reciprocal changes in histone lysine methylation/demethylation of M(LPS + IFN-γ)/M(IL-10) genes is one of the factors that direct macrophage polarization and contribute to host defense/susceptibility toward infection. Although, histone lysine methyltransferases and lysine demethylases orchestrate these events, their role remains elusive in visceral leishmaniasis, a disease associated with macrophage M(IL-10) polarization. In this study, we observed that L. donovani induced the expression of histone lysine methyltransferases Ash1l, Smyd2, and Ezh2 and histone lysine demethylases Kdm5b and Kdm6b in J774 macrophages and BALB/c mice. Chromatin immunoprecipitation analysis revealed that L. donovani facilitated H3K36 dimethylation at TNF-α promoter by Smyd2 and H3K27 trimethylation at inducible NO synthase promoter by Ezh2 to suppress their expression in macrophages. Furthermore, infection-induced Kdm5b and Kdm6b modulated H3K4 and H3K27 trimethylation at IL-12, TNF-α, and arginase-1 promoters, respectively, whereas H3K4 trimethylation by Ash1l at IL-10 promoter induced its expression. Analysis of transductional events revealed that HIF-1α upregulated Kdm5b and Kdm6b expression, whereas Ash1l and Ezh2 expression were induced by transcription factor MeCP2. Additionally, Smyd2 was induced by c-Myc in infected macrophages. Knockdown of Ash1l, Ezh2, Kdm5b, and Kdm6b by specific small interfering RNA and Vivo-Morpholino, as well as inhibition of Smyd2 by its specific inhibitor, AZ505, led to increased protective proinflammatory response and inhibited amastigote multiplication in infected J774 macrophages and BALB/c mice, respectively. Collectively, our findings demonstrate that L. donovani exploits specific histone lysine methyltransferases/demethylases to redirect epigenetic programming of M(LPS + IFN-γ)/M(IL-10) genes for its successful establishment within the host.

Coexpression Analysis of the EZH2 Gene Using The Cancer Genome Atlas and Oncomine Databases Identifies Coexpressed Genes Involved in Biological Networks in Breast Cancer, Glioblastoma, and Prostate Cancer.

BackgroundThis study aimed to perform coexpression analysis of the EZH2 gene using The Cancer Genome Atlas (TCGA) and the Oncomine databases to identify coexpressed genes involved in biological networks in breast cancer, glioblastoma, and prostate cancer, with functional analysis of the EZH2 gene in the C4-2 human prostate cancer cell line in vitro.Material/MethodsData from TCGA and Oncomine databases were analyzed to determine the expression of EZH2 and the top five coexpressed genes in breast cancer, glioblastoma, and prostate cancer and the clinical significance the coexpressed genes. Gene Ontology (GO) analysis was performed to predict the functions and pathways of EZH2 using pathway annotation. The role of EZH2 in the C4-2 human prostate cancer cell line was studied in vitro.ResultsAnalysis of 16 micro-arrays identified 185 genes that were coexpressed with EZH2. The top five coexpressed genes were MCM4, KIAA0101, MKI67, RRM2, and CDC25a. Increased expression of these genes and EZH2 were associated with reduced survival. Coexpressed genes were involved in biological networks associated with the cell cycle, mitosis, and DNA damage. The effects of EZH2 on prostate cancer cell was validated in vitro as knockdown of EZH2 resulted in a G2/M cell cycle arrest, increased DNA damage, and reduced colony number.ConclusionsCoexpression analysis of EZH2 identified its role in the cell cycle, mitosis, and DNA repair. The molecular mechanisms involved in EZH2 gene expression in the cell response to DNA damage requires further study to determine whether EZH2 is a potential human cancer biomarker.

METTL3 promotes the progression of nasopharyngeal carcinoma through mediating M6A modification of EZH2.

The aim of this study was to investigate whether METTL3 promoted the progression of nasopharyngeal carcinoma (NPC) by silencing CDKN1C through EZH2. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine the expression level of METTL3 in 48 pairs of NPC tissues and adjacent normal tissues. METTL3 expression in patients with different tumor lymph node metastasis (TNM) stages was detected by qRT-PCR as well. The Kaplan-Meier method was used to analyze the interplay between METTL3 expression and the prognosis of patients with NPC. At the same time, METTL3 expression in normal epithelial cell line (BEAS-2B) and NPC cell lines (SUNE-1 and C666-1) was examined using qRT-PCR. After METTL3 was knocked down in SUNE-1 cells, cell viability and migration abilities were analyzed by cell counting kit-8 (CCK-8) test and wound healing assay, respectively. The mRNA and protein expressions of EZH2 were detected by qRT-PCR and Western blot, respectively. RNA immunoprecipitation (RIP) assay was applied to detect the binding of METTL3 to EZH2 mRNA and the m6A modification on EZH2 mRNA. After knockdown of EZH2 in SUNE-1 cells, qRT-PCR was used to detect the mRNA expression of CDKN1C. Meanwhile, chromatin immunoprecipitation (ChIP) assay was conducted to analyze the binding of EZH2 to the CDKN1C promoter region. After down-regulation of METTL3 in SUNE-1 cells, the protein expressions of EZH2 and CDKN1C were detected using Western blot. After simultaneous knockdown of METTL3 and CDKN1C in SUNE-1 cells, CCK8 assay and wound healing assay were applied to examine cell viability and migration abilities. METTL3 expression in NPC tissues was remarkably higher than that of adjacent normal tissues. Meanwhile, METTL3 expression in T3 and T4 tumors was significantly higher than that of T1 and T2 tumors. In patients with lymph node metastasis, the expression of METTL3 was remarkably higher than those without metastasis. Survival analysis demonstrated that patients with higher expression of METTL3 exhibited significantly longer overall survival time than those with lower METTL3 expression. QRT-PCR revealed that METTL3 was highly expressed in NPC cell lines, including SUNE-1 and C666-1. After knock-down of METTL3 in SUNE-1 cells, cell viability and migration abilities were both markedly weakened. Meanwhile, the protein expression of EZH2 was remarkably reduced. However, no significant changes were observed in EZH2 mRNA level. RIP assay revealed that METTL3 could bind to EZH2 mRNA, and a m6A modification was verified on EZH2 mRNA. After knockdown of EZH2, the mRNA level of CDKN1C in SUNE-1 cells was significantly up-regulated. CHIP assay indicated that EZH2 could bind to CDKN1C. Western blot showed that, after interfering with METTL3 in SUNE-1 cells, the protein expression of EZH2 decreased significantly, while CDKN1C was up-regulated. In addition, simultaneous downregulation of METTL3 and CDKN1C in SUNE-1 cells reversed the influence of METTL3 on cell viability and migration abilities. METTL3 was highly expressed in NPC tissues, which might inhibit EZH2 expression by mediating M6A modification of EZH2 mRNA. Furthermore, CDKN1C could increase the malignancy of NPC cells and promote the progression of NPC.

MiR-33a functions as a tumor suppressor in triple-negative breast cancer by targeting EZH2

BackgroundIncreasing reports have confirmed that microRNAs play an important role in breast cancer progression, particularly in triple-negative breast cancer (TNBC). The aim of our study was to investigate the role of miR-33a in TNBC progression.MethodsPCR assays were performed to detect miR-33a and EZH2 expression in TNBC tissues, adjacent nontumor tissues and cell lines. Western blot, CCK8, Transwell, cell colony formation and EdU cell proliferation, cell cycle analysis and luciferase reporter assays were used to determine the regulation of miR-33a/EZH2 in TNBC progression.ResultsMiR-33a was significantly downregulated in TNBC tissues and cell lines. MiR-33a overexpression in TNBC cells significantly inhibited cell growth and mobility and induced G1 cell cycle arrest. The luciferase reporter assay revealed that EZH2 is a direct target of miR-33a and that it was upregulated in TNBC tissues and cell lines. There was a negative correlation between miR-33a and EZH2 expression in TNBC tissues. EZH2 knockdown exerted similar inhibitory effects, while ectopic expression of EZH2 showed suppressive effects on malignant behaviors induced by miR-33a overexpression in TNBC cells.ConclusionsThese findings revealed that miR-33a is a tumor-suppressive miRNA in TNBC and can inhibit proliferation and mobility and induce G1 cell cycle arrest by directly targeting EZH2.

Long non-coding RNA ANCR promotes progression of NSCLC by inhibiting E-Ca expression.

This study aimed to investigate whether long-chain non-coding ANCR is involved in the progression of non-small cell LCa (NSCLC) and its possible molecular mechanisms. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was applied to examine ANCR expression in 48 cases of NSCLC and adjacent normal tissues. In addition, ANCR level in patients of different tumor staging was analyzed. The Kaplan-Meier method was applied to analyze the interplay between ANCR expression and the prognosis of patients with NSCLC. Subsequently, qRT-PCR was performed to detect ANCR level in LCa cell lines. After knocking down ANCR in A549 cells, ANCR and E-Ca mRNA expression were examined by qRT-PCR, while the expression levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by Western blot. At the same time, cell viability and migration ability were analyzed through cell counting kit-8 (CCK-8) and cell wound healing assay, respectively. RNA immunoprecipitation (RIP) test was performed to verify the binding of ANCR to EZH2. After knocking down EZH2 in A549 cells, E-Ca messenger ribonucleic acid (mRNA) expression was detected. Additionally, Chromatin immunoprecipitation (ChIP) assay was performed to detect the binding of EZH2 to the E-Ca promoter region. When E-Ca and ANCR were simultaneously knocked down in A549 cells, Western blot investigation was performed to examine the expression of EMT-related proteins, while CCK-8 and wound healing assays were applied to figure out the changes in cell viability and cell migration capacity. ANCR level was conspicuously higher in NSCLC tissues than that in normal tissues, and that in T3 and T4 tumors was also higher than that in T1 and T2. Meanwhile, ANCR expression in the tissues of patients with lymph node metastasis was conspicuously higher than those without metastasis. Survival analysis revealed that the overall survival of patients with NSCLC with high expression of ANCR was conspicuously lower than patients with low expression of ANCR. The qRT-PCR study verified that ANCR was highly expressed in the LCa cell line A549. After knocking down ANCR in A549 cells, ANCR and E-Ca mRNA levels were found conspicuously decreased, and so were the expression levels of EMT-related proteins, as well as the cell viability and migration ability. The RIP assay result indicated that ANCR can indeed bind to EZH2. E-Ca mRNA expression was elevated after the knockdown of EZH2 in A549 cells. In addition, the result of CHIP test demonstrated that EZH2 could combine with E-Ca. Simultaneous down-regulation of ANCR and E-Ca in A549 cells could reverse the influence of knocking down ANCR alone on cell viability and migration ability. Long-chain non-coding RNA ANCR was highly expressed in NSCLC tissues and could enhance the viability and malignancy of NSCLC cells by inhibiting the expression of E-Ca, thereby promoting the progression of NSCLC.

EZH2 Loss Drives Resistance to Carboplatin and Paclitaxel in Serous Ovarian Cancers Expressing ATM.

Mechanisms of intrinsic resistance of serous ovarian cancers to standard treatment with carboplatin and paclitaxel are poorly understood. Seventeen primary serous ovarian cancers classified as responders or nonresponders to standard treatment were screened with DigiWest protein array analysis for 279 analytes. Histone methyl transferase EZH2, an interaction partner of ataxia telangiectasia mutated (ATM), was found as one of the most significantly represented proteins in responsive tumors. Survival analysis of 616 patients confirmed a better outcome in patients with high EZH2 expression, but a worse outcome in patients with low EZH2 and high-ATM-expressing tumors compared with patients with low EZH2 and low-ATM-expressing tumors. A proximity ligation assay further confirmed an association between ATM and EZH2 in tumors of patients with an increased disease-free survival. Knockdown of EZH2 resulted in treatment-resistant cells, but suppression of both EZH2 and ATM, or ATM alone, had no effect. DigiWest protein analysis of EZH2-knockdown cells revealed a decrease in proteins involved in mitotic processes and checkpoint regulation, suggesting that deregulated ATM may induce treatment resistance. IMPLICATIONS: Ovarian cancer is a malignancy with high mortality rates, with to date, no successful molecular characterization strategies. Our study uncovers in a comprehensive approach the involvement of checkpoint regulation via ATM and EZH2, potentially providing a new therapeutic perspective for further investigations.

LncRNA FOXC2-AS1 stimulates proliferation of melanoma via silencing p15 by recruiting EZH2.

The aim of this study was to elucidate the role of FOXC2-AS1 in promoting the proliferative ability and inhibiting apoptosis of melanoma by silencing p15, thereafter regulating the progression of melanoma. FOXC2-AS1 levels in melanoma patients with or without metastasis and those with the tumor in different stages were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Regulatory effects of FOXC2-AS1 on viability and apoptosis in melanoma cells were assessed, and subcellular distribution of FOXC2-AS1 was analyzed. Subsequently, the interactions of FOXC2-AS1 with EZH2 and SUZ12 were explored by RNA-Binding Protein Immunoprecipitation (RNA-RIP) assay. Through chromatin immunoprecipitation (ChIP) assay, the role of FOXC2-AS1 to regulate p15 transcription by recruiting EZH2 was verified. At last, regulatory effects of FOXC2-AS1/p15 axis on viability and apoptosis in melanoma cells were investigated. It was found that FOXC2-AS1 was upregulated in melanoma tissues, especially those with metastasis or stage II-IV. Melanoma patients expressing high level of FOXC2-AS1 showed worse survival than those with low level. Knockdown of FOXC2-AS1 inhibited viability, and stimulated apoptosis in A375 and sk-mel-110 cells. Besides, P15 level was upregulated in melanoma cells transfected with si-FOXC2-AS1, and FOXC2-AS1 was mainly distributed in cytoplasm. RNA-RIP assay confirmed that FOXC2-AS1 was mainly enriched in anti-EZH2 and aniti-SUZ12. Knockdown of EZH2 could markedly upregulate protein level of p15 in melanoma cells. Furthermore, it was verified that FOXC2-AS1 inhibited p15 transcription via recruiting EZH2, and the knockdown of p15 could partially reverse the regulatory effects of FOXC2-AS1 on viability and apoptosis in melanoma. FOXC2-AS1 stimulates proliferative ability in melanoma via silencing p15.

Long non-coding RNA AFAP1-AS1 promotes proliferation and migration of gastric cancer by downregulating KLF2.

To clarify the function of actin filament associated protein 1-antisense RNA1 (AFAP1-AS1) to promote the proliferation and migration of gastric cancer (GC) cells by downregulating Krüppel-like factor 2 (KLF2). Expression level of AFAP1-AS1 in GC tissues and matched paracancerous tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Besides, its level in GC either with lymphatic metastasis or not, and those in different tumor stages were determined as well. Regulatory roles of AFAP1-AS1 in cellular behaviors of GC cells were evaluated by functional experiments. The ability of AFAP1-AS1 to recruit EZH2 was evaluated through chromatin immunoprecipitation (ChIP) assay. The expression level of KLF2 in GC cells influenced by AFAP1-AS1 and EZH2 was detected by Western blot. Finally, a series of rescue experiments were conducted to clarify the role of AFAP-AS1/KLF2 in GC cell performances. AFAP1-AS1 was upregulated in GC tissues, and its expression in lymph node metastasis and progressive gastric cancer tissues were much higher. Knockdown of AFAP1-AS1 reduced the viability, proliferative and migratory abilities, but induced apoptosis of GC cells. AFAP1-AS1 was verified to bind to EZH2. After knockdown of AFAP1-AS1, the ability of AFAP1-AS1 to recruit EZH2 was remarkably attenuated. Knockdown of AFAP1-AS1 or EZH2 upregulated KLF2 expression in GC cells. Notably, knockdown of KLF2 partially reversed the effect of AFAP1-AS1 on GC cell performances. LncRNA AFAP1-AS1 accelerates the proliferative and migratory abilities of GC cells by downregulating the expression of KLF2, thus promoting the progression of GC.

Upregulated lncRNA CACNA1G-AS1 aggravates the progression of colorectal cancer by downregulating p53.

To investigate the role of long non-coding RNA (lncRNA) CACNA1G-AS1 in regulating proliferative and invasive abilities of colorectal cancer (CRC) cells by mediating p53, thus influencing the progression of CRC. CACNA1G-AS1 level in CRC tissues and adjacent normal tissues was first determined. Its level in CRC patients with different tumor stages was detected as well. Changes in proliferative and invasive abilities of HCT116 and SW480 cells influenced by CACNA1G-AS1 were evaluated. Subcellular distribution of CACNA1G-AS1 was analyzed. Through Western blot, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP) assay, the interaction between CACNA1G-AS1 and EZH2 was assessed. The biological function of the target gene of CACNA1G-AS1 was finally explored. CACNA1G-AS1 was upregulated in CRC tissues compared to adjacent normal ones. Its level remained higher in CRC patients with stage III-IV compared to those with stage I-II. Knockdown of CACNA1G-AS1 reduced proliferative and invasive abilities of HTC116 and SW480 cells. CACNA1G-AS1 was mainly distributed in the nucleus. Moreover, CACNA1G-AS1 was verified to interact with EZH2. Knockdown of CACNA1G-AS1 or EZH2 upregulated p53 level and decreased the recruitment ability of EZH2 on p53. Finally, p53 knockdown could partially reverse the regulatory effect of CACNA1G-AS1 on the proliferative ability of HCT116 cells. CACNA1G-AS1 downregulates p53 level by forming a carcinogenic complex with EZH2, thereby enhancing the proliferative and invasive abilities of CRC cells.

Maternal regulation of SATB2 in osteo-progeniters impairs skeletal development in offspring.

Nutritional status during intrauterine and/or early postnatal life has substantial influence on adult offspring health. Along these lines, there is a growing body of evidence illustrating that high fat diet (HFD)-induced maternal obesity can regulate fetal bone development. Thus, we investigated the effects of maternal obesity on both fetal skeletal development and mechanisms linking maternal obesity to osteoblast differentiation in offspring. Embryonic osteogenic calvarial cells (EOCCs) were isolated from fetuses at gestational day 18.5 (E18.5) of HFD-induced obese rat dams. We observed impaired differentiation of EOCCs to mature osteoblasts from HFD obese dams. ChIP-seq-based genome-wide localization of the repressive histone mark H3K27me3 (mediated via the polycomb histone methyltransferase, enhancer of zeste homologue 2 [Ezh2]) showed that this phenotype was associated with increased enrichment of H3K27me3 on the gene of SATB2, a critical transcription factor required for osteoblast differentiation. Knockdown of Ezh2 in EOCCs and ST2 cells increased SATB2 expression; while Ezh2 overexpression in EOCCs and ST2 cells decreased SATB2 expression. These data were consistent with experimental results showing strong association between H3K27me3, Ezh2, and SATB2 in cells from rats and humans. We have further presented that SATB2 mRNA and protein expression were increased in bones, and increased trabecular bone mass from pre-osteoblast specific Ezh2 deletion (Ezh2flox/flox Osx-Cre+ cko) mice compared with those from control Cre+ mice. These findings indicate that maternal HFD-induced obesity may be associated with decreasing fetal pre-osteoblastic cell differentiation, under epigenetic control of SATB2 expression via Ezh2-dependent mechanisms.

RETRACTED: linc01088 promotes cell proliferation by scaffolding EZH2 and repressing p21 in human non-small cell lung cancer

Non-small cell lung cancer (NSCLC), characterized by extensive metastasis and poor prognosis, is the most common type of lung cancer. Dysregulation of certain lncRNAs is known to be linked to the tumorigenesis of NSCLC. However, the specific roles in NSCLC for many other lncRNAs, such as linc01088, remain largely unknown. The expression patterns of linc01088, p21 and EZH2 were examined both in NSCLC tissues and cell lines using RT-qPCR assay. CCK-8, colony formation, immunofluorescence staining, and flow cytometry assays were employed to evaluate the effects of linc01088 on NSCLC cell proliferation properties. RNA immunoprecipitation (RIP) assay was performed to determine the direct binding relationship between linc01088 and zeste homolog 2 (EZH2). Western blot and RT-qPCR analysis were performed to assess p21 level within knockdown of either linc01088 or EZH2. Nude mouse subcutaneous NSCLC models were constructed for further validating the effects and mechanisms of linc01088 in vivo. linc01088 and EZH2 were highly expressed both in NSCLC tissues and cell lines. Knockdown of linc01088 suppressed the proliferation of NSCLC cells, and prolonged the G1 phase while shortened S and G2-M phases. RIP assay revealed the direct binding relationship between linc01088 and EZH2. Knockdown of either linc01088 or EZH2 induced up-regulation of p21 expression, which subsequently inhibited the tumor growth. We demonstrated that linc01088 could promote cell proliferation via binding with EZH2 to repress p21, which aggravates the tumorigenesis of NSCLC. Therefore, linc01088 might be a potential oncogene and target for novel anti-tumor therapies.

LncRNA MEG3 inhibits the progression of prostate cancer by facilitating H3K27 trimethylation of EN2 through binding to EZH2.

This study aims to study the effects of intra-nuclear lncRNA MEG3 on the progression of prostate cancer and the underlying mechanisms. Expressions of relative molecules were detected by Quantitative real time PCR (qRT-PCR) and western blot. Chromatin immunoprecipitation and RNA immunoprecipitation (RIP) assays were used to evaluate the interaction between intra-nuclear MEG3, histone methyltransferase EZH2 and Engrailed-2 (EN2). The impacts of MEG3 on the viability, proliferation and invasion of prostate cancer cells (PC3) were evaluated by methyl thiazolyl tetrazolium, colony formation and transwell assays, respectively. PC3 cells were transfected with MEG3 and transplanted into nude mice to analyse the effect of MEG3 on tumourigenesis of PC3 cells in vivo. EN2 expression was inversely proportional to MEG3 in the prostate cancer tissues and PC3 cells. RIP results showed that intra-nuclear MEG3 could bind to EZH2. Knockdown of MEG3 and/or EZH2 up-regulated EN2 expression and reduced the recruitment of EZH2 and H3K27me3 to EN2, while over-expressed MEG3 caused opposite effects. MEG3 over-expression suppressed cell viability, colony formation, cell invasion and migration of PC3 cells in vitro and inhibited tumourigenesis of PC3 cells in vivo, while EN2 over-expression diminished the effects. These findings indicated that MEG3 facilitated H3K27 trimethylation of EN2 via binding to EZH2, thus suppressed the development of prostate cancer.

LncRNA ZEB2-AS1 Aggravates Progression of Non-Small Cell Lung Carcinoma via Suppressing PTEN Level.

BackgroundThe aim of this study was to assess the involvement of lncRNA ZEB2-AS1 in the development of NSCLC and to explore the potential mechanism involved.Material/MethodsZEB2-AS1 expressions in 48 paired NSCLC tissues and paracancerous tissues were examined by qRT-PCR. ZEB2-AS1 level in NSCLC patients affected by tumor staging and lymphatic metastasis was examined as well. Regulatory effects of ZEB2-AS1 on proliferative, migratory, and invasive properties of NCI-H1650 and HCC827 cells were evaluated. The interaction between ZEB2-AS1 and EZH2 was identified through RIP assay. Subsequently, the binding of EZH2 on PTEN promoter region was tested by ChIP. Finally, rescue experiments were conducted to assess the involvement of PTEN in the development of NSCLC.ResultsZEB2-AS1 was upregulated in NSCLC tissues and cell lines. Its level was higher in NSCLC patients with T3–T4 or accompanied with lymphatic metastasis relative to those with T1–T2 or without metastatic loci. Knockdown of ZEB2-AS1 suppressed proliferative, migratory, and invasive properties of NCI-H1650 and HCC827 cells. PTEN level was elevated after knockdown of ZEB2-AS1 or EZH2 in HCC827 cells. Subsequently, RIP assay proved the interaction between ZEB2-AS1 and EZH2. Knockdown of ZEB2-AS1 markedly reduced the binding of EZH2 on the PTEN promoter region. Notably, knockdown of PTEN reversed the effects of EZB2-AS1 on regulating proliferative, migratory, and invasive properties of NSCLC cells.ConclusionslncRNA ZEB2-AS1 is upregulated in NSCLC, which elevates the viability and malignant degree of NSCLC cells by downregulating PTEN, thus aggravating the progression of NSCLC.

MiR-137 Deficiency Causes Anxiety-Like Behaviors in Mice.

Anxiety and depression are major public health concerns worldwide. Although genome-wide association studies have identified several genes robustly associated with susceptibility for these disorders, the molecular and cellular mechanisms associated with anxiety and depression is largely unknown. Reduction of microRNA-137 (miR-137) level has been implicated in the etiology of major depressive disorder. However, little is known about the in vivo impact of the loss of miR-137 on the biology of anxiety and depression. Here, we generated a forebrain-specific miR-137 knockout mouse line, and showed that miR-137 is critical for dendritic and synaptic growth in the forebrain. Mice with miR-137 loss-of-function exhibit anxiety-like behavior, and impaired spatial learning and memory. We then observe an elevated expression of EZH2 in the forebrain of miR-137 knockout mice, and provide direct evidence that knockdown of EZH2 can rescue anxious phenotypes associated with the loss of miR-137. Together our results suggest that loss of miR-137 contributes to the etiology of anxiety, and EZH2 might be a potential therapeutic target for anxiety and depressive phenotypes associated with the dysfunction of miR-137.