Transducin (β)-like 1 X-linked receptor 1 promotes gastric cancer progression via the ERK1/2 pathway

Gastric cancer (GC) is one of the most common types of cancer worldwide, and it involves extensive local tumour invasion, metastasis and poor prognosis. Understanding the mechanisms regulating the progression of GC is necessary for the development of effective therapeutic strategies. Transducin (β)-like 1 X-linked receptor 1 (TBL1XR1) is an important regulator controlling gene activation and repression, which has been thought to be involved in tumorigenesis. However, the role of TBL1XR1 in human GC remains largely unknown. Here, we find that TBL1XR1 is aberrantly expressed in human GC tissues, and TBL1XR1 levels are highly correlated with local tumour invasion, late tumor, lymph node, metastasis (TNM) stage and poor prognosis. Knockdown of TBL1XR1 by shRNA inhibits GC cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) in vitro, as well as tumorigenesis and peritoneal metastasis in vivo, whereas overexpression of TBL1XR1 produces the opposite effects. These effects are mediated by activation of the ERK1/2 signalling pathway, and inhibition of this pathway with a specific ERK1/2 inhibitor (U0126) significantly impairs the tumour-promoting effects induced by TBL1XR1. Moreover, TBL1XR1 mediated ERK1/2 activation is dependent on the β-catenin/MMP7/EGFR signalling pathway. In conclusion, TBL1XR1 contributes to GC tumorigenesis and progression through the activation of the β-catenin/MMP7/EGFR/ERK signalling pathway and may act as a new therapeutic target for GC.

PFKFB3 potentially contributes to paclitaxel resistance in breast cancer cells through TLR4 activation by stimulating lactate production

Paclitaxel is a commonly used agent for breast cancer therapy, which comes across the obstacle "drug resistance", resulting in shortened overall survival of patients. Warburg effect has become one character of cancer cell and was reported to induce paclitaxel resistance, the mechanism of which is poorly understood. In this study, we sought to examine the role of 6-Phosphofructo-2-kinase (PFKFB3), a critical regulator of glycolysis, in paclitaxel resistance development. Two clones of paclitaxel resistant breast cancer cells, MCF-7RA and MCF-7RB, were established by a long term exposure of MCF-7 cells to paclitaxel. Consequently, PFKFB3 expression was found to be increased in MCF-7RA and MCF-7RB cells compared with MCF-7 cells. Silencing PFKFB3 expression markedly reduced the IC50 concentrations of MCF-7RA and MCF-7RB cells. Moreover, PFKFB3 modulated toll like receptor 4 (TLR4) and MyD88 expression as well as interleukin (IL)-6 and IL-8 release from breast cancer cells in response to paclitaxel exposure. In addition, PFKFB3 overexpression boosted up fructose-2,6-bisphosphate (F2,6BP) and lactate production. The enhanced lactate contributed to TLR4 signaling activation, IL-6 and IL-8 generation, and cell viability promotion in MCF-7 cells. In all, we characterized the novel role of PFKFB3 in induction of paclitaxel resistance by raising lactate production and activating TLR4 signaling.

Solution-Processed 8-Hydroquinolatolithium as Effective Cathode Interlayer for High-Performance Polymer Solar Cells

Solution-processed 8-hydroxyquinolinatolithium (s-Liq) was successfully applied as an efficient cathode interlayer in bulk heterojunction polymer solar cells (PSCs), giving rise to enhancement in device performance. The ultraviolet photoelectron spectra results revealed that the presence of s-Liq could lower work function of Al cathode, allowing for the ohmic contacts with the fullerene acceptor for better electron extraction and also a larger work function difference between the two electrodes, which leads to an increase in open-circuit voltage (V(oc)). Scanning Kelvin probe microscopy study on the surface potential of active layers suggested that an interfacial dipole was formed in the s-Liq interlayer between the active layer and the Al cathode, which enhanced the intrinsic built-in potential in the device for better charge transportation and extraction. Consequently, the V(oc), fill factor, and current density of the device can be improved by the introduction of s-Liq interlayer, leading to a power conversion efficiency (PCE) improvement. With PTB7 (or PTB7-Th) as the donor and PC71BM as the acceptor, the s-Liq-based PSC devices exhibited a PCE of 8.37% (or 9.04%), much higher than those of devices with the evaporated Liq (7.62%) or commonly used PFN (8.14%) as the cathode interlayer. Moreover, the s-Liq-based devices showed good stability, maintaining 75% (in N2) and 45% (in air) of the initial PCE after 7 days, respectively. These results suggest the great potential of s-Liq as cathode interlayer material for high-performance solar cells application.

Mutations in WT1 in boys with sporadic isolated steroid-resistant nephrotic syndrome

Mutations in the Wilms' tumor gene, WT1, can lead to syndromic steroid-resistant nephrotic syndrome and isolated steroid-resistant nephrotic syndrome. WT1 mutations have been identified in the majority of children with Denys-Drash or Frasier syndrome. WT1 mutations have not previously been identified in boys with sporadic isolated steroid-resistant nephrotic syndrome, but, recently, four boys with isolated nephrotic syndrome were identified to have WT1 mutations. However, whether boys with sporadic isolated steroid-resistant nephrotic syndrome should be routinely subjected to mutation analysis of WT1 has not been established. We examined 35 boys with sporadic isolated steroid-resistant nephrotic syndrome for mutations in WT1. Mutation analysis of all 10 exons of WT1 was performed by polymerase chain reaction and direct sequencing. Karyotype analysis or Y chromosome identification was performed for all patients. A Y chromosome or a 46, XY karyotype was demonstrated for all 35 patients. No causative WT1 mutation was identified in any of the patients. The WT1 mutation, IVS4+14T>C, which is not predicted to affect splicing, was identified in one patient who achieved complete remission after 8 weeks of oral prednisone treatment, indicating that IVS4+14T>C is not a causative mutation. Five WT1 polymorphisms were also identified in some patients and controls. Our results suggest that mutation analysis of WT1 should not be routinely performed for genetically defined boys with sporadic isolated steroid-resistant nephrotic syndrome.

A High-Resolution Imaging Technique using a Whole-body, Research Photon Counting Detector CT System

A high-resolution (HR) data collection mode has been introduced to the whole-body, research photon-counting-detector CT system installed in our laboratory. In this mode, 64 rows of 0.45 mm × 0.45 mm detectors pixels were used, which corresponded to a pixel size of 0.225 mm × 0.225 mm at the iso-center. Spatial resolution of this HR mode was quantified by measuring the MTF from a scan of a 50 micron wire phantom. An anthropomorphic lung phantom, cadaveric swine lung, temporal bone and heart specimens were scanned using the HR mode, and image quality was subjectively assessed by two experienced radiologists. Comparison of the HR mode images against their energy integrating system (EID) equivalents using comb filters was also performed. High spatial resolution of the HR mode was evidenced by the MTF measurement, with 15 lp/cm and 20 lp/cm at 10% and 2% MTF. Images from anthropomorphic phantom and cadaveric specimens showed clear delineation of small structures, such as lung vessels, lung nodules, temporal bone structures, and coronary arteries. Temporal bone images showed critical anatomy (i.e. stapes superstructure) that was clearly visible in the PCD system but hardly visible with the EID system. These results demonstrated the potential application of this imaging mode in lung, temporal bone, and vascular imaging. Other clinical applications that require high spatial resolution, such as musculoskeletal imaging, may also benefit from this high resolution mode.

Does infrared or ultraviolet light damage the lens?

In daylight, the human eye is exposed to long wavelength ultraviolet radiation (UVR), visible radiation and short wavelength infrared radiation (IRR). Almost all the UVR and a fraction of the IRR waveband, respectively, left over after attenuation in the cornea, is absorbed in the lens. The time delay between exposure and onset of biological response in the lens varies from immediate-to-short-to-late. After exposure to sunlight or artificial sources, generating irradiances of the same order of magnitude or slightly higher, biological damage may occur photochemically or thermally. Epidemiological studies suggest a dose-dependent association between short wavelength UVR and cortical cataract. Experimental data infer that repeated daily in vivo exposures to short wavelength UVR generate photochemically induced damage in the lens, and that short delay onset cataract after UVR exposure is photochemically induced. Epidemiology suggests that daily high-intensity short wavelength IRR exposure of workers, is associated with a higher prevalence of age-related cataract. It cannot be excluded that this effect is owing to a thermally induced higher denaturation rate. Recent experimental data rule out a photochemical effect of 1090 nm in the lens but other wavelengths in the near IRR should be investigated.

A trinuclear ruthenium complex as a highly efficient molecular catalyst for water oxidation

A trinuclear catalyst, 3, was synthesized based on Ru(bda) (bda = 2,2′-bipyridine-6,6′-dicarboxylic acid)-type catalysts to achieve higher catalytic abilities in homogeneous water oxidation systems.

Dysregulated module approach identifies disrupted genes and pathways associated with acute myelocytic leukemia

OBJECTIVE

To identify disrupted genes and pathways involved in acute myelocytic leukemia (AML) by systematically tracking the dysregulated modules across normal and AML conditions.

MATERIALS AND METHODS

In this study, we firstly integrated the protein interaction data and expression profiles to infer and reweight the normal and AML networks using Pearson correlation coefficient (PCC). Next, clustering-based on maximal cliques (CMC) approach and a maximum weight bipartite matching method were implemented to infer the condition-specific modules and capture the disturbed modules, respectively, from two conditional networks. Then, the gene compositions and functional enrichment analysis were performed to identify the dysregulated genes and pathways. Finally, reverse transcription polymerase chain reaction (RT-PCR) was implemented to study the expression level of several key genes in AML patients.

RESULTS

In two conditional-specific networks, universal changes of gene correlations were revealed, making the differential correlation density among disrupted module pairs. In this work, a total of 84 altered modules were identified by comparing modules in normal and AML networks. Functional enrichment analysis showed that genes in altered modules mainly involved in cell cycle, nucleic acids and cancer signaling process, and differentially expressed genes (DEGs) and changed gene correlations were mainly participated in natural killer cell-mediated cytotoxicity and acute myeloid leukemia pathway. The key genes, such as MYC, EGFR, MAPK1 and CCNA1, were all significantly differentially expressed in AML patients.

CONCLUSIONS

This module approach effectively identifies dysregulated pathways and genes associated with AML. The considerable differences of gene correlations yield to these dysfunctional modules, and the coordinated disruption of these very modules contributes to leukemogenesis.

Sarcopenia, as defined by low muscle mass, strength and physical performance, predicts complications after surgery for colorectal cancer

AIM

Recent studies have shown that sarcopenia is associated with negative postoperative outcomes. However, none of these studies analysed muscle strength or physical performance, which are also important components of sarcopenia. The present study aimed to investigate whether sarcopenia itself, as defined by low muscle mass, strength and physical performance, would predict complications after surgery for colorectal cancer.

METHOD

We conducted a prospective study of patients who underwent surgery for colorectal cancer at our department between August 2014 and February 2015. Sarcopenia was diagnosed by a combination of third lumbar vertebra muscle index (L3 MI), handgrip strength and 6-m usual gait speed. Univariate and multivariate analyses evaluating the risk factors for postoperative complications were performed. Only complications classified as Grade II or above according to the Clavien-Dindo classification were analysed in this study.

RESULTS

A total of 142 patients were included in the study, and 17 patients were diagnosed as having sarcopenia. Postoperative complications of Grade II or above occurred in 40 patients, including 10 with sarcopenia and 30 without sarcopenia. Multivariate analysis showed that sarcopenia and previous abdominal surgery were independent risk factors for postoperative complications. Patients with sarcopenia also had an obvious tendency to a higher incidence of infectious complications. By comparing two logistic regression models, sarcopenia showed a better predictive power for postoperative complications than did low muscle mass.

CONCLUSION

Sarcopenia and previous abdominal surgery are independent risk factors for complications after surgery for colorectal cancer. Including a functional aspect to the definition of sarcopenia may result in a better prediction of postoperative complications.

Local cytotoxic T-lymphocyte-associated antigen-4 immunoglobulin inhibition of rejection response is dependent on indoleamine 2,3-dioxygenase activities in the allograft

A previous study showed that local gene transfer of cytotoxic T-lymphocyte-associated antigen-4 immunoglobulin (CTLA4Ig) significantly prolonged the survival time of rat flap allografts. However, the underlying mechanism is not fully understood. Indoleamine 2,3-dioxygenase (IDO) is considered to be able to modulate the unresponsiveness state of allografts. In this study, we tested the expression of the CD80 molecule, IDO mRNA, and the level of the tryptophan metabolite kynurenine with or without the application of the IDO blocker 1-methyl-tryptophan (1-MT) in a rat composite tissue allotransplantation model. CD80 expression could be detected in the allograft. The ration of IDO mRNA/glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA and the level of kynurenine were both enhanced (46.3 ± 8.8 versus 4.6 ± 1.8 and 18.9 ± 1.3 μmol/L versus 2.1 ± 0.2 μmol/L separately) after adenovirus-mediated CTLA4Ig (AdCTLA4Ig) transduction. When 1-MT was applied to the AdCTLA4Ig perfusion recipients, the ration of IDO mRNA/GAPDH mRNA (5.2 ± 2.9) and the level of kynurenine (0.8 ± 0.5 μmol/L) were significantly reduced. Moreover, the allograft survival time was greatly reduced when 1-MT was applied to AdCTLA4Ig perfusion recipients compared to single AdCTLA4Ig perfusion therapy recipients (7.2 days versus 13.6 days). We showed that the inhibitory effect of locally delivered CTLA4Ig is dependent on IDO activities within the allograft.

A rabbit model of antegrade selective cerebral perfusion with cardioplegic arrest

OBJECTIVE

Due to the weak ascending aorta, it is extremely challenging to establish an anterograde selective cerebral perfusion (ASCP) model in rabbits, especially when cardioplegic arrest is required. Herein, the aim of this study was to establish a rabbit ASCP model with cardiac arrest being easily performed and being similar to the clinical scenario.

MATERIALS AND METHODS

Twenty-two adult New Zealand white rabbits were selected for ASCP model establishment and another 22 rabbits were utilized for blood donation. The cardiopulmonary bypass (CPB) circuit consisted of a roller pump, a membrane oxygenator, a heat-cooler system and a blood reservoir, which were connected by silicone tubing. The total priming volume of the circuit was 70 ml. Cannulations on the right and left subclavian arteries were used for arterial inflow and cardioplegia perfusion, respectively. Venous drainage was conducted through the right atrial appendage. ASCP was initiated by clamping the innominate artery; the flow rate was maintained 10 ml/kg/minute and sustained for 60 minutes. After 120 minutes of reperfusion, the rabbits were sacrificed. The mean arterial pressure, heart rate, electrocardiogram and urine output were monitored. Arterial blood samples were analyzed at the following time points: after anesthesia, immediately after CPB, after aorta cross-clamping and cardioplegia perfusion, 5 min after the re-opening of the aorta and at CPB termination.

RESULTS

ASCP modeling was performed successfully on 18 rabbits and 4 rabbits unsuccessfully. Vital signs and blood gas indictors changed in an acceptable range throughout the experiments. One rabbit had ventricular fibrillation after re-opening of the ascending aorta. Obvious hemodilution occurred after the perfusion of cardioplegia, but the hematocrit improved after CPB termination.

CONCLUSION

By using cannulation of the subclavian artery rather than the aorta and with a low priming volume, we established a modified rabbit model of ASCP with cardioplegic arrest. The model has excellent repeatability and operability, which is similar to the clinic process and is suitable for the study of cerebral, cardiac and renal protection.

Noise-induced damage to ribbon synapses without permanent threshold shifts in neonatal mice

Recently, ribbon synapses to the hair cells (HCs) in the cochlea have become a novel site of interest in the investigation of noise-induced cochlear lesions in adult rodents (Kujawa and Liberman, 2009; Lin et al., 2011; Liu et al., 2012; Shi et al., 2013). Permanent noise-induced damage to this type of synapse can result in subsequent degeneration of spiral ganglion neurons (SGNs) in the absence of permanent changes to hearing sensitivity. To verify whether noise exposure during an early developmental period produces a similar impact on ribbon synapses, the present study examined the damaging effects of noise exposure in neonatal Kunming mice. The animals received exposure to broadband noise at 105-decibel (dB) sound pressure level (SPL) for 2h on either postnatal day 10 (P10d) or postnatal day 14 (P14d), and then hearing function (based on the auditory brainstem response (ABR)) and cochlear morphology were evaluated during either postnatal weeks 3-4 (P4w) or postnatal weeks 7-8 (P8w). There were no significant differences in the hearing threshold between noise-exposed and control animals, which suggests that noise did not cause permanent loss of hearing sensitivity. However, noise exposure did produce a significant loss of ribbon synapses, particularly in P14d mice, which continued to increase from P4w to P8w. Additionally, a corresponding reduction in the amplitude of compound action potential (CAP) was observed in the noise-exposed groups at P4w and P8w, and the CAP latency was elongated, indicating a change in synaptic function.

Changes in diversity of cultured bacteria resistant to erythromycin and tetracycline in swine manure during simulated composting and lagoon storage

This study investigated the impact of composting and lagoon storage on survival and change in diversity of tetracycline-resistant (Tc(r) ) and erythromycin-resistant (Em(r) ) bacteria and the resistance genes they carry in swine manure. Treatments were arranged as a 2 × 2 factorial design: composting vs lagoon storage and 0 vs 1% Surround WP Crop Protectant (a clay product) in three replicates. After 48 days of treatments, resistant bacteria were enumerated by selective plating and identified by 16S rRNA gene sequencing. The erm and the tet gene(s) carried by the resistant isolates were screened using class-specific PCR assays. The plate counts of Tc(r) and Em(r) bacteria decreased by 4-7 logs by composting, but only by 1-2 logs by the lagoon treatment. During the treatments, Acinetobacter gave way to Pseudomonas and Providencia as the largest resistant genera. The clay product had little effect on survival or diversity of resistant bacteria. Of six classes of erm and seven classes of tet genes tested, changes in prevalence were also noted. The results indicate that composting can dramatically shift Tc(r) and Em(r) bacterial populations, and composting can be an effective and practical approach to decrease dissemination of antibiotic resistance from swine farms to the environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presented research provided evidence that composting is much more effective than lagoon storage in dramatically decreasing culturable bacteria resistant to erythromycin and tetracycline in swine manure. Considerable diversity changes of resistant bacteria were also demonstrated during composting or lagoon storage. Overall, Acinetobacter was the major resistant genus in untreated swine manure, but pseudomonads and Providencia became the major resistant genera after the treatments. This is the first study that investigated diversity changes of cultured bacteria resistant to these two antibiotics during composting and lagoon storage of swine manure. New genes encoding resistance to the two antibiotics were also implied in the cultured isolates.

Enhanced T-cell activation and differentiation in lymphocytes from transgenic mice expressing ubiquitination-resistant 2KR LAT molecules

Linker for activation of T cells (LAT) is critical for the propagation of T-cell signals upon T-cell receptor (TCR) activation. Previous studies demonstrated that substitution of LAT lysines with arginines (2KR LAT) resulted in decreased LAT ubiquitination and elevated T-cell signaling, indicating that LAT ubiquitination is a molecular checkpoint for attenuation of T-cell signaling. To investigate the role of LAT ubiquitination in vivo, we have generated transgenic mice expressing WT and ubiquitin-defective 2KR LAT. On TCR stimulation of T cells from these mice, proximal signaling and cytokine production was elevated in 2KR versus wild-type (WT) LAT mice. Enhanced cytolytic activity as well as T-helper responses were observed on LAT expression, which were further elevated by 2KR LAT expression. Despite greater T-effector function, WT or 2KR LAT expression did not have any effect on clearance of certain pathogens or tumors. Our data support the model that lack of tumor clearance is due to increased differentiation and acquisition of effector phenotype that is associated with suboptimal immunity in an immunotherapy model. Thus, our data further reinforce the role of LAT ubiquitination in TCR signaling and uncovers a novel role for LAT in driving T-cell differentiation.

A NOVEL FLT4 GENE MUTATION AND MR LYMPHANGIOGRAPHY IN A CHINESE FAMILY WITH MILROY DISEASE

Milroy disease is a congenital onset lymphedema linked to FLT4 gene mutations in the tyrosine kinase domain. So far, a total of 59 different FLT4 variants have been identified. Here, we report a novel FLT4 gene mutation in a Chinese family with Milroy disease and present their clinical symptoms and MR lymphangiographic findings.

B-type natriuretic peptide and cirrhosis progression

Brain natriuretic peptide (BNP) is used as a marker of cardiac dysfunction to predict heart failure mortality. The significance of the prognostic ability of BNP for liver cirrhosis remains unknown, although the levels of BNP seen in cirrhosis are high. We aimed to determine whether the BNP level is related to the stage of cirrhosis and could serve as a prognostic marker of cirrhosis (predict the 1-year all-cause mortality). We recruited 92 patients at different stages of cirrhosis and 81 controls matched by age and gender for this study. At admission, cardiac physical examination and BNP measurements were performed. Upon discharge, the 89 patients were followed up for 12 months. The median BNP levels of patients with cirrhosis were 167.0 pg/mL, which were significantly higher than those of the control group (167.0 vs 34.8 pg/mL, P = 0.001). Serum BNP levels were positively correlated with the Child score, the grade of esophageal varices, a history of spontaneous bacterial peritonitis, and the presence of ascites and collateral circulation. BNP levels above the median were associated with an increased occurrence of death within 12 months of discharge (log rank P = 0.025), as determined by univariate and multivariate Cox regression analyses. Esophageal varices, large/medium volume ascites, and BNP levels were related to the clinical outcome (P = 0.034, 0.030, and 0.025, respectively). Together, these results suggested that serum BNP levels are significantly correlated with the stage of cirrhosis, suggesting that BNP levels might serve as a significant predictor for 1-year all-cause mortality.

Effects of garlic oil, nitrate, saponin and their combinations supplemented to different substrates on in vitro fermentation, ruminal methanogenesis, and abundance and diversity of microbial populations

AIMS

To investigate the effect of garlic oil (G), nitrate (N), saponin (S) and their combinations supplemented to different forage to concentrate substrates on methanogenesis, fermentation, diversity and abundances of bacteria and Archaea in vitro.

METHODS AND RESULTS

The study was conducted in an 8 × 2 factorial design with eight treatments and two substrates using mixed ruminal batch cultures obtained. Quillaja S (0·6 g l(-1) ), N (5 mmol l(-1) ) and G (0·27 g l(-1) ) were used separately or in binary and tertiary combinations. The two substrates contained grass hay and a dairy concentrate mixture at a 70 : 30 (high-forage substrate) ratio or a 30 : 70 (high-concentrate substrate) ratio. Ruminal fermentation and cellulolytic bacterial populations were affected by interaction between substrate and anti-methanogenic compounds. The inhibitor combinations decreased the methane production additively regardless of substrate. For the high-concentrate substrate, S decreased methane production to a greater extent, so did G and N individually for the high-forage substrate. Feed degradability and total volatile fatty acid (VFA) concentrations were not decreased by any of the treatments. Fibre degradability was actually improved by N+S for the high-forage substrate. VFA concentrations and profiles were affected differently by different anti-methanogenic inhibitors and their combinations. All treatments inhibited the growth of Archaea, but the effect on Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens varied.

CONCLUSIONS

The results suggest that substrate influences the efficacy of these inhibitors when they are used separately, but in combinations, they can lower methanogenesis additively without much influence from the substrate.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presented research provided evidence that binary and tertiary combination of garlic oil, nitrate and saponin can lower the methane production additively without adversely impacting rumen fermentation and degradability, and forage to concentrate ratio does not change the above effects. These anti-methanogenic inhibitors in combination may have practical application to mitigate methane emission from ruminants.

Development of secondary mutations in wild-type and mutant EZH2 alleles cooperates to confer resistance to EZH2 inhibitors

The histone methyltransferase Enhancer of Zeste Homolog 2 (EZH2) is frequently dysregulated in cancers, and gain-of-function (GOF) EZH2 mutations have been identified in non-Hodgkin lymphomas. Small-molecule inhibitors against EZH2 demonstrated anti-tumor activity in EZH2-mutated lymphomas and entered clinical trials. Here, we developed models of acquired resistance to EZH2 inhibitor EI1 with EZH2-mutated lymphoma cells. Resistance was generated by secondary mutations in both wild-type (WT) and GOF Y641N EZH2 alleles. These EZH2 mutants retained the substrate specificity of their predecessor complexes but became refractory to biochemical inhibition by EZH2 inhibitors. Resistant cells were able to maintain a high level of H3K27Me3 in the presence of inhibitors. Interestingly, mutation of EZH2 WT alone generated an intermediate resistance phenotype, which is consistent with a previously proposed model of cooperation between EZH2 WT and Y641N mutants to promote tumorigenesis. In addition, the findings presented here have implications for the clinical translation of EZH2 inhibitors and underscore the need to develop novel EZH2 inhibitors to target potential resistance emerging in clinical settings.