Nucleus pulposus (NP) cell pyroptosis is crucial for intervertebral disc degeneration (IDD). However, the precise mechanisms underlying pyroptosis in IDD remain elusive. Therefore, this study aimed to investigate how dickkopf-1 (DKK1) influences NP cell pyroptosis and delineate the regulatory mechanisms of IDD. Behavioral tests and histological examinations were conducted in rat IDD models to assess the effect of DKK1 on the structure and function of intervertebral discs. Detected pyroptosis levels using Hoechst 33,342/propidium iodide (PI) double staining, and determined pyroptosis-related protein expression via western blotting. The cellular mechanisms of DKK1 in pyroptosis were explored in interleukin (IL)-1β-induced NP cells transfected with or without DKK1 overexpression plasmids (oe-DKK1). In addition, IL-1β-treated NP cells transfected with sh-EZH2 and/or sh-DKK1 were utilized to clarify the interplay between the enhancer of zeste homologue 2 (EZH2) and DKK1 in pyroptosis. Additionally, the epigenetic regulation of DKK1 by EZH2 was explored in NP cells treated with the EZH2 inhibitors GSK126/DZNep. DKK1 expression decreased in IDD rats. Transfection with oe-DKK1 reduced pro-inflammatory factors and extracellular matrix markers in IDD rats. In IL-1β-induced NP cells, DKK1 overexpression suppressed pyroptosis and inhibited the NLRP3 and NAIP/NLRC4 inflammasome activation. EZH2 knockdown increased DKK1 expression and reduced pyroptosis-related proteins. Conversely, DKK1 downregulation reversed the inhibitory effects of EZH2 knockdown on pyroptosis. Furthermore, EZH2 suppressed DKK1 expression via H3K27 methylation at the DKK1 promoter. EZH2 negatively regulates DKK1 expression via H3K27me3 methylation, promoting NP cell pyroptosis in IDD patients. This regulatory effect involves the activation of NLRP3 and NAIP/NLRC4 inflammasomes.

Enhancer of zeste homologue 2 (EZH2) is a clarified promoter in a list of tumours, including osteosarcoma (OS). Our research was projected to define the mechanism involved in EZH2-mediated OS progression through the protein kinase B (AKT)/glycogen synthase kinase 3β (GSK3β) pathway. EZH2 expression was tested in 66 OS tissues and five osteosarcoma cell lines (143B, SJSA-1, HOS, MG63, and U2OS). In HOS and U2OS cells, cellular malignant characteristics, and the markers of the AKT/GSK3β signalling pathway were measured when EZH2 was silenced or overexpressed. Meanwhile, rescue assays were implemented to observe whether the AKT/GSK3β signalling pathway inhibitor (MK-2206) could affect the role of overexpressed EZH2 in OS cells. EZH2 was up-regulated in tumour tissues of OS patients. OS cell lines (HOS and U2OS) showed impairments of proliferative, migratory, invasive and anti-apoptotic properties when EZH2 was silenced. Downregulated EZH2 inhibited the activation of the AKT/GSK3 signalling pathway. However, the situation in HOS and U2OS cells over-expressing EZH2 was opposite. MK-2206 erased EZH2 up-regulation-induced promotion of OS cell growth. It is demonstrated that EZH2 promotes the progression of OS via inducing the activation of the AKT/GSK3β pathway, offering a therapeutic direction for OS treatment.

Following the publication of this paper, it was drawn to the Editors\' attention by a concerned reader that the Transwell cell migration assay data shown in Fig. 2D and 6D, and the scratch‑wound assay data in Figs. 2E and 6E, were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 16: 9494‑9502, 2017; DOI: 10.3892/mmr.2017.7828].

UNASSIGNED: Bone cancer pain (BCP) seriously affects the quality of life of patients with advanced cancer, but effective treatment methods are lacking. This study mainly investigates the role of EZH2 in a well-established BCP model induced by Walker 256 breast cancer cells in rats.
UNASSIGNED: Female Sprague-Dawley rats of the same age weighing approximately 160 g were selected for the experiment. The BCP model was established by injecting inactivated Walker 256 breast cancer cells into the tibia. von Frey filaments were used to measure the paw withdrawal threshold, and bone destruction in the rat was observed using x-ray. The spinal EZH2 and H3K27Tm levels were measured using Western blotting and RT-qPCR analysis. Intrathecal injection of an EZH2 inhibitor was performed to examine the role of EZH2 in trigeminal BCP.
UNASSIGNED: Experimental results showed that injecting Walker 256 breast cancer cells into the tibia induced bone cancer pain. Spinal EZH2 and H3K27Tm levels were significantly increased over time in BCP rats. An intrathecal injection of 3-deazaneplanocin A (DZNep), a selective EZH2 inhibitor, downregulated the expression of EZH2 and attenuate the BCP-induced mechanical allodynia state.
UNASSIGNED: Intrathecal injection of DZNep relieve bone cancer pain in rats. EZH2 expressed in spinal cord tissue may be involved in the process of bone cancer pain in rats.

Breast cancer (BC) is the most common gynecologic tumor worldwide where aberrant expression of microRNAs (miRNAs) is frequently involved. Here, we evaluated the function of miR-375 on BC development and the molecules implicated. Differentially expressed genes between tumor and paired normal tissues from BC patients were screened out by microarray analyses. miR-375 was abundantly expressed in BC tissues and cells, and it was correlated with the poor prognosis of patients. Downregulation of miR-375 was introduced into BC cell lines MCF-7 and HCC1954, after which the viability, colony formation, migration, and invasion were suppressed, while the apoptosis of cells was increased, and the xenograft tumors in nude mice were reduced as well. EZH2 increased methylation and phosphorylation of signal transducer and activator of transcription 3 (STAT3) and increased transcription activity of miR-375, while miR-375 directly targeted FOXO1. Either overexpression of EZH2 or downregulation of FOXO1 blocked the functions of anti-miR-375 in cells and animals. FOXO1 was found as an activator of the p53 signaling pathway. This study showed that miR-375 is an important oncogene in BC. EZH2 is an upstream regulator of miR-375 through mediating the methylation of STAT3, while FOXO1 is a downstream target mRNA of miR-375 that activates the p53 signaling pathway to suppress BC development.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief as there are concerns about the reliability of the results. Concerns have been raised about a portion of Figure 5B, ‘DMSO’ group appears to contain image similarities with Figure 4e, ‘Inhibitor NC’ group, published in Yang et al., 2021 doi: 10.1080/15384101.2020.1856498. A portion of Figure 5B, ‘DZNeP+miR-30d-3p antagomir’ group appears to contain image similarities with Figure 4e, ‘Inhibitor NC’ group, published in Yang et al., 2021. Figure 7/G western blot bands have the same eyebrow shaped phenotype as many other publications as detailed here (https://pubpeer.com/publications/B26AE47AC0E71E0EF339B40893B2C2).

Recently, the role of microRNAs (miRs) in human diseases has been verified. This study was determined to explore the protective effects of microRNA-26a (miR-26a) in steroid-induced osteonecrosis of the femoral head (SONFH) with the involvement of enhancer of zeste homologue 2 (EZH2).Femoral head (FH) samples from SONFH patients and patients with femoral neck fracture were collected, and rat SONFH models were established by Escherichia coli endotoxin combining with large dose steroid pulse assay. The hemorheology, blood lipid, inflammatory factors, and pathologic changes were measured by a series of experiments. Moreover, the detection of osteoblasts, osteoclasts, miR-26a expression, EZH2 expression, osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL), and the apoptosis of osteocytes were conducted. The target relation between miR-26a and EZH2 was clarified by bioinformatics and dual-luciferase reporter gene assay.MiR-26a was poorly expressed, while EZH2 was highly expressed in SONFH, and the elevation of miR-26a could repress EZH2 expression. Elevated miR-26a and reduced EZH2 were able to decelerate the apoptosis of osteocytes, increase osteoblasts, and decrease osteoclasts, resulting in a repression of SONFH progression. Additionally, EZH2 was a target gene of miR-26a. Furthermore, the elevation of EZH2 could reverse the repression of SONFH progression that is induced by elevated miR-26a.We found that up-regulation of miR-26a and knockdown of EZH2 could suppress the development of SONFH, which would contribute to the therapy of SONFH.

BACKGROUND: Increasing evidence suggests the involvement of enhancer of zeste homologue 2 (EZH2) in chemoresistance of cancer treatment. Nevertheless, its function and molecular mechanisms in gastric cancer (GC) chemoresistance are still not well elucidated.
METHODS: In the present study, we investigated the functional role of EZH2 in 5-fluorouracil (5-FU) resistance of GC cells and discovered the underlying molecular mechanism.
RESULTS: Results revealed that EZH2 was upregulated in 5-FU-resistant GC tissues and cell lines. High ZEH2 expression was correlated with poor prognosis of GC patients. EZH2 knockdown enhanced 5-FU sensitivity of AGS/5-FU and SGC-7901/5-FU cells. Moreover, EZH2 could epigenetically suppress FBXO32 expression. FBXO32 overexpression could mimic the functional role of downregulated EZH2 in 5-FU resistance. FBXO32 knockdown counteracted the inductive effect of EZH2 inhibition on 5-FU sensitivity of AGS/5-FU and SGC-7901/5-FU cells. Furthermore, EZH2 knockdown facilitated 5-FU sensitivity of 5-FU-resistant GC cells in vivo.
CONCLUSIONS: In summary, EZH2 depletion overcame 5-FU resistance in GC by epigenetically silencing FBXO32, providing a novel therapeutic target for GC chemoresistance.

A useful candidate for small-cell lung cancer (SCLC) therapy is immune checkpoint blockade therapy targeting programmed death-1 (PD-1) and its ligand, PD-L1. Furthermore, rovalpituzumab tesirine (Rova-T), a delta-like protein 3 (DLL3)-targeted antibody-drug conjugate, and enhancer of zeste homologue 2 (EZH2) inhibitor are expected to be the first targeted therapy for SCLC. The aim of the present study was to evaluate PD-L1, DLL3 and EZH2 expression in SCLCs to find a candidate responder to those therapies. Immunohistochemical (IHC) staining for PD-L1, DLL3 and EZH2 was performed in 20 patients with SCLC and the clinicopathological characteristics and IHC staining intensity were compared. It was demonstrated that 1/20 patients (5.0%) exhibited positive PD-L1 expression in the metastatic lesions, as well as in the primary lung tumor. DLL3 was highly expressed in 14/20 patients (70%) and EZH2 was positive in 17/20 patients (85%). None of these cases exhibited any correlation with age, sex, smoking, stage or treatment, whereas IHC staining was able to identify candidate responders to anti-PD-L1/PD-1 immunotherapy, Rova-T therapy, or EZH2 inhibitor therapy.

MicroRNA (miR)-138 generally has a suppressive role in various human cancer types; however, its role and the underlying mechanisms in laryngeal squamous cell carcinoma (LSCC) have remained to be elucidated. The present study assessed the clinical significance and regulatory mechanisms of miR-138 in LSCC progression. Reverse-transcription quantitative polymerase chain reaction analysis indicated that miR-138 was significantly downregulated in LSCC tissues and cell lines. In addition, the decreased expression of miR-138 was significantly associated with poor differentiation, lymph node metastasis and advanced clinical stage of LSCC. Restoration of miR-138 expression caused a significant decrease in the proliferation of Hep-2 LSCC cells, while knockdown of miR-138 significantly promoted Hep-2 cell proliferation. A luciferase reporter assay further identified enhancer of zeste homologue 2 (EZH2) as a direct target gene of miR-138, and the protein expression of EZH2 was negatively regulated by miR-138 in Hep-2 cells. Furthermore, overexpression of EZH2 eliminated the suppressive effects of miR-138 on Hep-2 cell proliferation via activation of phosphoinositide-3 kinase (PI3K)/AKT signaling. In addition, EZH2 was found to be significantly upregulated in LSCC tissues and to be inversely correlated to the miR-138 levels. The results of the present study demonstrated that miR-138 inhibits the proliferation of LSCC cells, at least partly via targeting EZH2 and inhibiting PI3 K/AKT signaling. The present study highlighted the clinical significance of the miR-138/EZH2 axis in LSCC.