Identification and Analysis of NnOMT and NnNMT Gene Families in Nelumbo nucifera / 中国实验方剂学杂志

ObjectiveThe biosynthetic pathways of benzylisoquinoline alkaloids（BIAs） in Nelumbo nucifera are of great theoretical and economic value. In this paper， N. nucifera O-methyltransferase（NnOMT） and N. nucifera N-methyltransferase（NnNMT） gene families were identified and analyzed by bioinformatics in order to facilitate the biosynthetic pathway of BIAs in N. nucifera. MethodBased on the whole genome of N. nucifera， UniPort and National Center for Biotechnology Information（NCBI） databases were used to identify the NnOMT and NnNMT gene families of N. nucifera， and analyze their physicochemical properties and subcellular localization， then TBtools， MEME， MEGA 11.0， FigTree 1.4.4 and other tools were used to analyze the phylogeny， sequence characteristics， gene structure， functional annotation and cis-acting elements of NnOMT and NnNMT genes identified in the previous stage. ResultA total of 61 NnOMT and NnNMT genes were identified in this paper， the number of amino acids encoded by these genes ranged from 168 aa to 580 aa， the isoelectric point ranged from 4.76 to 9.16， and the relative molecular weight ranged from 18 699.52 Da to 64 934.53 Da， most of which showed acidic and mostly hydrophilic proteins. There were 10 conserved motifs， Kyoto Encyclopedia of Genes and Genomes（KEGG） analysis enriched a total of 12 pathways， including metabolism， biosynthesis of phenylpropane and isoquinoline alkaloids， etc. And Visualization of Gene Ontology（GO） enrichment results showed that 61 NnOMT and NnNMT genes were annotated to 32 items， which included 16 molecular functions［such as reduced nicotinamide adenine dinucleotide（NADH） activity and exopeptidase activity］ and 16 biological processes（such as metabolic process of carbon tetrachloride， anaerobic carbon tetrachloride metabolic process and responses to exogenous biological stimuli）. There were a variety of cis-acting elements in the promoter regions of NnOMT and NnNMT genes， mainly promoter and enhancer regions element， light responsive element and methyl jasmonate responsive element. ConclusionIn this study， a comprehensive bioinformatics analysis of 61 NnOMT and NnNMT genes is carried out based on the genome data of N. nucifera， which lays a foundation for research on the gene structure and function of NnOMT and NnNMT gene families， and provides a reference for biosynthetic pathway elucidation of BIAs in N. nucifera.

Role of Histone Methyltransferase in Fibrosis and Traditional Chinese Medicine Treatment： A Review / 中国实验方剂学杂志

Fibrosis， a tumor-like lesion between benign tissue and malignant tumor， mostly occurs in the liver， kidney， heart， lung， bone marrow and other organs and tissues. It can affect almost every organ and eventually induce multiple organ failure and cancers， seriously endangering human life. It will be of great importance to prevent cancer if the disease can be opportunely blocked in the fibrotic stage. The pathogenesis of fibrosis is still not completely clear. It is of great clinical significance to study the occurrence， development， and mechanism of fibrosis as well as to screen new therapeutic targets. Enhancer of zeste homolog 2 （EZH2） is mainly located in the nucleus and involved in the formation of the polycomb repressive complex 2. EZH2 is a methyltransferase which makes the lysine on position 27 of histone H3 （H3K27me3） undergo trimethyl modification induces gene silencing through classical or nonclassical actions， so as to inhibit or activate transcription. EZH2 plays a critical role in cell growth， proliferation， differentiation， and apoptosis， which is regulated by different targets and signaling pathways. EZH2 regulates the transformation of myofibroblasts and participates in the fibrosis of multiple organs. Recent studies have shown that EZH2 plays a role in fibrosis-related pathophysiological processes such as epithelial-mesenchymal transition， oxidative stress， and inflammation. EZH2 as the target of fibrosis， EZH2 inhibitors， and EZH2-related traditional Chinese medicine （TCM） formula and active compounds have gradually become hot research directions. EZH2 may be a powerful target for organ fibrosis. Exploring the structure， function， and distribution of EZH2， the role of EZH2 in fibrosis， the EZH2 inhibitors， and TCM formulas and active components targeting EZH2 has great meanings. This paper reviews the research progress in EZH2 and fibrosis， providing new ideas for the diagnosis， treatment， and drug development of fibrosis.

Inhibitory Effect and Mechanism of Sishenwan-containing Serum on Aerobic Glycolysis in Human Colon Cancer Cells / 中国实验方剂学杂志

ObjectiveTo explore the effect and mechanism of Sishenwan-containing serum on aerobic glycolysis in human colon cancer HCT116 cells. MethodCell counting kit-8 （CCK-8） was used to detect the cell viability of colon cancer HCT116 cells after treatment with Sishenwan-containing serum （2.5%， 5%， and 10%） for 24， 48， 72 h. The concentration of lactic acid， the content of intracellular glucose， and the activity of hexokinase （HK） and fructose-6-phosphate kinase （PFK） in the cell culture medium were detected by the micro-method. The content of glucose transporter 1 （GluT1） mRNA was detected by Real-time quantitative polymerase chain reaction （Real-time PCR）. The protein expression of GluT1 and methyltransferase-like 3 （MettL3） was detected by Western blot. The expression of GluT1 in cells was detected by immunofluorescence and the level of N6-methyladenosine （m6A） RNA methylation was detected by colorimetry. ResultCompared with the normal serum， 2.5%， 5%， and 10% Sishenwan-containing serum had no significant effect on the viability of HCT116 cells at 24 h， while 10% Sishenwan-containing serum showed a significant inhibitory effect on the viability of HCT116 cells at 48 h （P<0.05）. Hence， 10% Sishenwan-containing serum was used in subsequent experiments， and the intervention time was 48 h. Compared with the normal serum， 10% Sishenwan-containing serum could reduce lactate production （P<0.05）， down-regulate glucose uptake （P<0.05）， and blunt the activities of HK and PFK， the key rate-limiting enzymes of glycolysis （P<0.05）. Meanwhile， 10% Sishenwan-containing serum could decrease the expression of GluT1 protein （P<0.01） and mRNA （P<0.05） and reduce the proportion of cells expressing GluT1 （P<0.01）. Compared with the normal serum， Sishenwan-containing serum also decreased the protein content of MettL3 （P<0.05） and the methylation level of m6A RNA （P<0.01）. ConclusionSishenwan can inhibit glycolysis in colon cancer cells， and its inhibitory mechanism may be related to reducing MettL3 overexpression， inhibiting m6A RNA methylation， and down-regulating GluT1 and the activities of intracellular aerobic glycolysis-related enzymes such as HK and PFK.

The key role of RNA N 6-methyladenosine (m 6A) methylation in tumor radiotherapy and radiation damage repair / 中华放射医学与防护杂志

N 6-methyladenosine (m 6A) is the most abundant epigenetic modification in eukaryotic messenger RNA (mRNA), which could be catalyzed by m 6A methyltransferase (Writers), recognized by methylation recognition enzymes (Readers), and removed by demethylase (Erasers). RNA splicing, translation, and stability could be modulated by m 6A methylation modification. The m 6A methylation modification is involved in the biological regulation of a variety of important functional genes in cellular activities. Importantly, abnormal m 6A modification affects the occurrence, development, metastasis and recurrence of tumors. Ionizing radiation can affect the level of m 6A and m 6A methylation-related enzymes. Recently, m 6A methylation is reported to regulate the efficacy of tumor radiotherapy by affecting DNA damage and radiosensitivity of tumor cells. In addition, ionizing radiation can also affect the level of m 6A modification in normal cells to regulate the progress of radiation-induced injuries. This review summarizes the research progress on the roles of m 6A methylation in tumor radiosensitivity and radiation-induced injuries, with the aim of providing novel strategies for the development of clinical tumor radiosensitizers and radioprotective agents.

Changes of plasma METTL3, WTAP and FTO levels in patients with systemic lupus erythematosus and their correlation with clinical indicators / 中国医师杂志

Objective:To explore the clinical significance of N6-methyladenine (m6A) in systemic lupus erythematosus (SLE) by comparing the changes in plasma levels of m6A modification related proteins [methyltransferase 3 (METTL3), methyltransferase 14 (METTL14), Wilms tumor 1 associated protein (WTAP), AlkB homologous protein 5 (ALKBH5), and fat mass and obesity-associated protein (FTO)] and m6A between patients with systemic lupus erythematosus (SLE) and healthy controls.Methods:A total of 64 SLE patients admitted to the Seventh Affiliated Hospital of Sun Yat-Sen University from May 2020 to June 2022 and 24 healthy volunteers during the same period were selected to compare and analyze the plasma levels of METTL3, METTL14, WTAP, ALKBH5, FTO and m6A between the two groups. The correlation between METTL3, WTAP, FTO levels and clinical indicators was analyzed.Results:The plasma METTL3 level of SLE patients was significantly higher than that of control group ( P<0.05), and the plasma WTAP and FTO levels were significantly lower than those of control group (all P<0.05). In SLE patients, plasma METTL3 level was negatively correlated with hemoglobin level ( r=-0.344, P<0.05), plasma FTO level was positively correlated with plasma IgM level ( r=0.337, P<0.05), and plasma IgA level was negatively correlated with SLE patients ( r=-0.286, P<0.05). The incidence of renal involvement and positive rate of plasma anti-histone antibody were higher in SLE patients with high METTL3 level (all P<0.05). The positive rates of plasma anti-dsDNA antibody, anti-SM antibody and AuaA antibody were higher in SLE patients with low FTO level (all P<0.05). Conclusions:The plasma METTL3 level in SLE patients are significantly increased, while the plasma WTAP and FTO levels are significantly reduced, which are related to various clinical indicators and may be related to the onset of SLE.

Inhibition of histone methyltransferase PRMT5 attenuates cisplatin-induced hearing loss through the PI3K/Akt-mediated mitochondrial apoptotic pathway / 药物分析学报

This study aimed to evaluate the therapeutic potential of inhibiting protein arginine methyltransferase 5(PRMT5)in cisplatin-induced hearing loss.The effects of PRMT5 inhibition on cisplatin-induced auditory injury were determined using immunohistochemistry,apoptosis assays,and auditory brainstem response.The mechanism of PRMT5 inhibition on hair cell survival was assessed using RNA-seq and Cleavage Under Targets and Tagment-quantitative polymerase chain reaction(CUT&Tag-qPCR)analyses in the HEI-OC1 cell line.Pharmacological inhibition of PRMT5 significantly alleviated cisplatin-induced damage to hair cells and spiral ganglion neurons in the cochlea and decreased apoptosis by protecting mitochondrial function and preventing the accumulation of reactive oxygen species.CUT&Tag-qPCR analysis demonstrated that inhibition of PRMT5 in HEI-OC1 cells reduced the accumulation of H4R3me2s/H3R8me2s marks at the promoter region of the Pik3ca gene,thus activating the expression of Pik3ca.These findings suggest that PRMT5 inhibitors have strong potential as agents against cisplatin-induced ototoxicity and can lay the foundation for further research on treatment strategies of hearing loss.

Novel insights into histone lysine methyltransferases in cancer therapy:From epigenetic regulation to selective drugs / 药物分析学报

The reversible and precise temporal and spatial regulation of histone lysine methyltransferases(KMTs)is essential for epigenome homeostasis.The dysregulation of KMTs is associated with tumor initiation,metastasis,chemoresistance,invasiveness,and the immune microenvironment.Therapeutically,their promising effects are being evaluated in diversified preclinical and clinical trials,demonstrating encouraging outcomes in multiple malignancies.In this review,we have updated recent understandings of KMTs'functions and the development of their targeted inhibitors.First,we provide an updated overview of the regulatory roles of several KMT activities in oncogenesis,tumor suppression,and im-mune regulation.In addition,we summarize the current targeting strategies in different cancer types and multiple ongoing clinical trials of combination therapies with KMT inhibitors.In summary,we endeavor to depict the regulation of KMT-mediated epigenetic landscape and provide potential epigenetic targets in the treatment of cancers.

Advances in histone epigenetic enzyme inhibitors based on proteomics / 药学学报

As an important component of nucleosomes on the chromatin of eukaryotic cells, histones play an important role in the development and progression of tumour diseases by regulating epigenetic post-translational modifications such as acetylation and methylation. In addition, development of inhibitors targeting methyltransferase and deacetylase provides novel therapeutic strategies for cancer treatment. Mass spectrometry-based proteomics can reveal the global changes of histone modifications under the action of drugs during disease progression, which in turn provides important support for revealing drug action mechanism, drug resistance mechanism, and investigating novel drug combination strategies. This article focuses on the progress and status of proteomic research on a variety of histone modifying enzyme inhibitors, including methyltransferase inhibitors and histone deacetylase inhibitors, which will help to understand the current and further utilization of proteomics in studying histone modifications.

Casticin Attenuates Stemness in Cervical Cancer Stem-Like Cells by Regulating Activity and Expression of DNMT1 / 中国结合医学杂志

OBJECTIVE@#To explore whether casticin (CAS) suppresses stemness in cancer stem-like cells (CSLCs) obtained from human cervical cancer (CCSLCs) and the underlying mechanism.@*METHODS@#Spheres from HeLa and CaSki cells were used as CCSLCs. DNA methyltransferase 1 (DNMT1) activity and mRNA levels, self-renewal capability (Nanog and Sox2), and cancer stem cell markers (CD133 and CD44), were detected by a colorimetric DNMT activity/inhibition assay kit, quantitative real-time reverse transcription-polymerase chain reaction, sphere and colony formation assays, and immunoblot, respectively. Knockdown and overexpression of DNMT1 by transfection with shRNA and cDNA, respectively, were performed to explore the mechanism for action of CAS (0, 10, 30, and 100 nmol/L).@*RESULTS@#DNMT1 activity was increased in CCSLCs compared with HeLa and CaSki cells (P<0.05). In addition, HeLa-derived CCSLCs transfected with DNMT1 shRNA showed reduced sphere and colony formation abilities, and lower CD133, CD44, Nanog and Sox2 protein expressions (P<0.05). Conversely, overexpression of DNMT1 in HeLa cells exhibited the oppositive effects. Furthermore, CAS significantly reduced DNMT1 activity and transcription levels as well as stemness in HeLa-derived CCSLCs (P<0.05). Interestingly, DNMT1 knockdown enhanced the inhibitory effect of CAS on stemness. As expected, DNMT1 overexpression reversed the inhibitory effect of CAS on stemness in HeLa cells.@*CONCLUSION@#CAS effectively inhibits stemness in CCSLCs through suppression of DNMT1 activation, suggesting that CAS acts as a promising preventive and therapeutic candidate in cervical cancer.

Mechanism of berberine inhibiting invasion and migration of renal carcinoma cells by down-regulating the expression of METTL3 / 中国药房

OBJECTIVE To investigate the inhibitory effect of berberine （BER） on the invasion and migration of human renal carcinoma cells and its potential mechanism. METHODS Using human renal carcinoma OSRC-2 cell as object， alamarBlue assay was adopted to detect the inhibitory effects of 0 （control group）， 25， 50， 75， 100， 125， 150， 175 and 200 μmol/L BER on the proliferation of OSRC-2 cell after treatment for 24 h and 48 h. After treated with 0（control group）， 50， 100 μmol/L BER for 48 h， the effect of BER on cell cycle was analyzed by flow cytometry. The migration of OSRC-2 cells in 24 h and 36 h was observed by cell scratch test， and the invasion ability of OSRC-2 cells in 24 h was detected by Transwell assay. The protein expression of methyltransferase-like 3 （METTL3） was detected by Western blot after treatment for 48 h， and RNA methylation quantification kit was used to detect the levels of N6-methyladenosine （m6A） in OSRC-2 cells. RESULTS Compared with control group， BER at different concentrations could significantly decrease the survival rate of OSRC-2 cells （P＜0.01）， and showed a dose-dependent and time-dependent manner. After 48 h of BER treatment at 50， 100 μmol/L， the cell was arrested in G0/G1 phase （P＜0.01）. Compared with control group， the migration and invasion abilities of cells in 50， 100 μmol/L BER group were significantly decreased （P＜0.05 or P＜0.01）； the protein expression of METTL3 and the level of m6A in RNA were significantly decreased （P＜0.01）. CONCLUSIONS BER can inhibit level of m6A by down-regulating the expression of METTL3， thereby inhibiting the invasion and metastasis of human renal carcinoma cells.

Identification and expression analysis of flavonoid O-methyltransferases gene family in Artemisia argyi / 药学学报

italic>Artemisia argyi (A. argyi) is a Chinese herbal medicine in China. The main active components are volatile oils, flavonoids, and other compounds, which have various pharmacological activities. Methoxylated flavonoids are the main active ingredients in A. argyi. Flavonoid O-methyltransferase (FOMT) is a key enzyme in the O-methylation of flavonoids. In order to further understand the function and characteristics of FOMT proteins, this paper carried out the whole genome mining and identification of FOMT genes in A. argyi and performed phylogenetic, chromosomal localization, gene sequence characterization, subcellular localization prediction, protein structure, gene structure analysis, and expression pattern analysis. The results showed that a total of 83 FOMT genes were identified in the genome of A. argyi. The phylogenetic tree shows that FOMT genes are divided into two subgroups, CCoAOMT (caffeoyl CoA O-methyltransferase) subfamily (32 genes) and COMT (caffeic acid O-methyltransferase) subfamily (51 genes). Gene sequence analysis showed that the number of amino acids encoded by FOMT was 70-734 aa, the molecular weight was 25 296.55-34 241.3 Da, and the isoelectric point was 4.51-9.99. Compared with 32 members of the CCoAOMT subfamily, nearly 1/3 of the 51 members of the COMT subfamily were hydrophobic proteins and 2/3 were hydrophilic proteins. Subcellular localization prediction showed that more than 80% of CCoAOMT subfamily members were located in the cytoplasm, and 96% of COMT subfamily members were located in the chloroplast. COMT subfamily members have more motifs than CCoAOMT subfamily members. The N-terminal motifs of COMT subfamily proteins are relatively variable, while the C-terminal motifs are relatively conserved. Expression pattern analysis showed that CCoAOMT subfamily members were mainly expressed in roots, while COMT members were mainly expressed in leaves. Some FOMTs showed the tissue expression specificity by real-time quantitative PCR analysis, especially in leaves. In this study, we identified and analyzed the FOMT gene family in A. argyi, and provided a theoretical basis for further research on the function of FOMTs and the biosynthesis of methylated flavonoids in A. argyi.

A novel O-methyltransferase with substrate promiscuity from Ardisia japonica / 药学学报

italic>O-methyltransferases (OMTs) are one of the key tailoring enzymes in the biosynthesis of many natural products, O-methylation can not only reduce the reactivity of natural products, but also alter their solubility, stability and biological activities. Based on the transcriptome data of Ardisia japonica, a full-length cDNA sequence of candidate OMT (termed as AjOMT1) was cloned by reverse transcription-polymerase chain reaction (RT-PCR) and expressed in Escherichia coli (E. coli) for the first time. In vitro enzyme catalytic activity assay showed that the recombinant AjOMT1 could effectively catalyze quercetin to form O-methylated products. Most importantly, AjOMT1 showed unprecedented substrate promiscuity towards structurally various compounds including flavonoids, stilbenes, coumarins, alkaloids and phenylpropanoids, especially preferring to the compounds with adjacent phenolic hydroxyl groups, and showed regio-selectivity. These results suggested that AjOMT1 could be used as the tool enzyme to conduct O-methylation of different types of compounds to produce diverse active methylated products, and provide a new method for drug discovery, even universal part for synthetic biology of natural products.

Mechanism of m6A methyltransferase 3 in the pathogenesis of diabetic cataract / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the role and mechanism of N6-methyladenosine(m6A)methyltransferase 3(METTL3)in the pathogenesis of diabetic cataract.METHODS: We cultured SRA01/04 cells in low and high sugar media for 24h and measured changes in epithelial-mesenchymal transition(EMT)indicators(E-Cadherin, N-Cadherin, ZO-1 and α-SMA)using RT-qPCR and Western blot assays. Cell migration was also assessed using transwell and scratch assays. To investigate the expression level and localization of METTL3 in human lens anterior capsules tissues. Additionally, we used m6A dot blot assay to detect the m6A methylation level of cells cultured in low and high glucose media for 24h, and employed RT-qPCR and Western blot experiments to detect RNA and protein expression of METTL3 in cells. We then treated the cells with METTL3 inhibitor and measured changes in EMT markers by RT-qPCR and Western blot; m6A methylation level was detected by m6A dot blot test; cell migration was detected by Transwell. Finally, the expression of transforming growth factor-β(TGFβ1)in cultured cells was assessed by immunofluorescence staining and the expression levels of TGFβ1 and SNAIL in cells were determined using RT-qPCR and Western blot.RESULTS: Under high glucose conditions, the expression of EMT markers, METTL3, and m6A methylation levels were significantly increased in cells(P&#x003C;0.05). Furthermore, the migratory ability of cells was higher in high-sugar medium than in low-sugar medium. In human lens anterior capsules, METTL3 expression was higher in patients with diabetic cataract compared to those with age-related cataract. Importantly, treatment with the METTL3 inhibitor STM2457 inhibited EMT in cells, the expression of TGFβ1 and SNAIL, as well as m6A methylation levels in cells(all P&#x003C;0.05)compared to high-sugar + dimethyl sulfoxide(DMSO)group. Moreover, the migratory capacity of cells was reduced after the addition of STM2457 compared to the high-sugar + DMSO group.CONCLUSION:METTL3 promotes the EMT in human lens epithelial cells under high glucose conditions by activating the TGFβ1/SNAIL pathway, thus contributing to the development of diabetic cataracts.

Methyltransferase-like 3-mediated N6-methyladenosine methylation modification regulates the biological activity of vascular endothelial cells via the Notch pathway / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the role and mechanism of methyltransferase-like 3(METTL3)-mediated N6-methyladenosine(m6A)methylation modification in regulating biological activity of vascular endothelial cells in the pathogenesis of choroidal neovascularization.METHODS: Human umbilical vein endothelial cells(HUVEC)cultured in vitro were divided into the following groups: control group(normal culture), low density lipoprotein(LDL)group, fluorescence-labelled LDL(Dil-LDL)group, 12.5μg/mL and 25μg/mL oxidized LDL(ox-LDL)groups, 12.5μg/mL and 25μg/mL fluorescence-labelled ox-LDL(Dil-ox-LDL)groups, DMSO group, STM2457(METTL3 inhibitor)group, DAPT group; and monkey retina-choroidal endothelial cells(RF/6A)cultured in vitro were divided into control group, DMSO group, 12.5 μg/mL ox-LDL group, and DAPT group. Endocytosed lipoprotein level was examined through fluorescence microscopy. RNA m6A methylation level was detected through a dot blot assay. Protein and RNA levels of METTL3 or angiogenesis-related markers were measured through Western blot assays and real-time quantitative polymerase chain reaction(RT-qPCR), respectively. METTL3 expression and localization were investigated through immunofluorescence. Cell migratory and tube formation capacities were assessed through transwell migration and tube formation assays, respectively.RESULTS: Endocytosed lipoprotein levels in HUVECs exposed to Dil-LDL, 12.5μg/mL and 25μg/mL Dil-ox-LDL groups were significantly higher than those in the control group. 12.5μg/mL and 25μg/mL ox-LDL groups significantly increased m6A methylation(all P&#x003C;0.05), METTL3 protein expression(all P&#x003C;0.01), and cell migration and angiogenesis capacities(all P&#x003C;0.01). METTL3 mRNA level was significantly unregulated in the 12.5μg/mL ox-LDL group(P&#x003C;0.05). In comparison to the DMSO group, the addition of STM2457 caused significant decrease in m6A methylation level(P&#x003C;0.05), expression of VEGF and other angiogenesis-related markers(all P&#x003C;0.05), cell migration and angiogenesis capacities(all P&#x003C;0.01)and the expression of NICD(P&#x003C;0.05). However, there were no significant differences in METTL3 protein and mRNA levels(all P&#x003E;0.05). The expression of VEGF and NICD(all P&#x003C;0.05), as well as the ability of cell migration and angiogenesis of RF/6A, was all significantly decreased in the DAPT group compared to the DMSO group(all P&#x003C;0.01).CONCLUSION: METTL3-mediated m6A methylation modification promotes angiogenesis in vascular endothelial cells via the Notch signaling pathway in the pathogenesis of choroidal neovascularization.

Targeting TRMT5 suppresses hepatocellular carcinoma progression via inhibiting the HIF-1α pathways / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Accumulating evidence has confirmed the links between transfer RNA (tRNA) modifications and tumor progression. The present study is the first to explore the role of tRNA methyltransferase 5 (TRMT5), which catalyzes the m1G37 modification of mitochondrial tRNAs in hepatocellular carcinoma (HCC) progression. Here, based on bioinformatics and clinical analyses, we identified that TRMT5 expression was upregulated in HCC, which correlated with poor prognosis. Silencing TRMT5 attenuated HCC proliferation and metastasis both in vivo and in vitro, which may be partially explained by declined extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Mechanistically, we discovered that knockdown of TRMT5 inactivated the hypoxia-inducible factor-1 (HIF-1) signaling pathway by preventing HIF-1α stability through the enhancement of cellular oxygen content. Moreover, our data indicated that inhibition of TRMT5 sensitized HCC to doxorubicin by adjusting HIF-‍1α. In conclusion, our study revealed that targeting TRMT5 could inhibit HCC progression and increase the susceptibility of tumor cells to chemotherapy drugs. Thus, TRMT5 might be a carcinogenesis candidate gene that could serve as a potential target for HCC therapy.

Progress of enhancer of zeste homolog 2 in hematological tumors / 白血病·淋巴瘤

The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase, which is widely studied in histone methylation modification. It can promote epigenetic gene silencing and mediate the occurrence of tumors through a variety of regulatory mechanisms. The gain-of-function and loss-of-function mutations of EZH2 have been confirmed in many cancers. At present, with the extensive attention paid to the regulatory role of EZH2 in epigenetic mechanism, the exact way in which EZH2 imbalance affects the pathogenesis of hematologic malignancies remains to be clarified. This article reviews the pathogenetic role of EZH2 in hematological tumors, and hope to find new targets for the prevention and treatment of hematological tumors.

Progress of tumor suppressor genes MLL3 in leukemia / 白血病·淋巴瘤

MLL3 is also known as lysine methyltransferase 2C (KMT2C). The mutation of MLL3 can occur in a variety of human cancers, including leukemia, liver cancer, and stomach cancer. The effect of MLL3 in different cancers is also different, for example, MLL3 is carcinogenic in pancreatic and liver cancer, while it acts as a tumor suppressor in acute myeloid leukemia and esophageal squamous cell carcinoma. The effects of genes in tumors depend on certain environment and conditions, and the mechanism of the suppressive effect of MLL3 in leukemia is still not clear. This paper reviews the research progress of the antitumor mechanism of MLL3 in leukemia.

Effect of Catechol-O-Methyltransferase Genotype on Self-Reported Efficacy and Activity Changes in the Brain Prefrontal Area in Response to a Caffeine Placebo / 医薬品情報学

Objective: The placebo effect can enhance the response to treatment, even in the absence of pharmacological ingredients. One possible factor explaining the likelihood of the placebo effect in individuals is genetic polymorphisms in neurotransmitters. This study focused on gene polymorphisms in the catechol-O-methyltransferase (COMT) as an interindividual variable of the placebo effect.Design・Methods: All 120 participants were explained the effects of caffeine, including its ability to ameliorate drowsiness and increase concentration, and then given a placebo (lactose). The onset of the placebo effect was measured in terms of the degree of caffeine-reduced sleepiness using subjective indices of the Stanford Sleepiness Scale (SSS) and a feeling of drowsiness-Visual Analogue Scale (VAS). The mechanism of the placebo effect was objectively examined in terms of changes in cerebral blood flow in the prefrontal cortex of the brain. In addition, we investigated participants’ susceptibility to the placebo effect by examining genetic polymorphisms in COMT.Results: After taking the drug, sleepiness on the SSS and VAS was significantly improved (p＜0.001), although there was no change in prefrontal cortex activity. Among the 120 participants, 63 had a Val/Val-type polymorphism in COMT (52.5%), 45 had a Val/Met-type (37.5%), and 12 had a Met/Met-type (10.0%). There were no significant differences among COMT gene polymorphisms in the subjective measures of SSS and VAS. However, there was a tendency for the cerebral blood flow changes to be larger in the left hemisphere of the brain in individuals with the Met/Met type.Conclusion: There seems to be a relationship between prefrontal cortex activity and genetic polymorphisms. In particular, there may be a correlation between the expression of a placebo effect and COMT gene polymorphisms.

Evidence of a synthetic lethality interaction between SETDB1 histone methyltransferase and CHD4 chromatin remodeling protein in a triple negative breast cancer cell line

During the tumorigenic process, cancer cells may become overly dependent on the activity of backup cellular pathways for their survival, representing vulnerabilities that could be exploited as therapeutic targets. Certain molecular vulnerabilities manifest as a synthetic lethality relationship, and the identification and characterization of new synthetic lethal interactions may pave the way for the development of new therapeutic approaches for human cancer. Our goal was to investigate a possible synthetic lethal interaction between a member of the Chromodomain Helicase DNA binding proteins family (CHD4) and a member of the histone methyltransferases family (SETDB1) in the molecular context of a cell line (Hs578T) representing the triple negative breast cancer (TNBC), a subtype of breast cancer lacking validated molecular targets for treatment. Therefore, we employed the CRISPR-Cas9 gene editing tool to individually or simultaneously introduce indels in the genomic loci corresponding to the catalytic domains of SETDB1 and CHD4 in the Hs578T cell line. Our main findings included: a) introduction of indels in exon 22 of SETDB1 sensitized Hs578T to the action of the genotoxic chemotherapy doxorubicin; b) by sequentially introducing indels in exon 22 of SETDB1 and exon 23 of CHD4 and tracking the percentage of the remaining wild-type sequences in the mixed cell populations generated, we obtained evidence of the existence of a synthetic lethality interaction between these genes. Considering the lack of molecular targets in TNBC, our findings provided valuable insights for development of new therapeutic approaches not only for TNBC but also for other cancer types.

Effects and molecular mechanism of histone methyltransferase enhancer of zeste homolog 2 on regulating sepsis-induced T cell dysfunction / 中华危重病急救医学

Objective:To investigate the effect and mechanism of histone methyltransferase enhancer of zeste homolog 2 (EZH2) on sepsis-induced T cell dysfunction.Methods:Twenty-four male C57BL/6 mice were divided into three groups randomly: sham operated group, sepsis model group [cecum ligation and puncture (CLP)+dimethyl sulfoxide (DMSO) group] and EZH2 selective inhibitor treated group (CLP+GSK126 group), with 8 mice in each group. Sepsis murine model was reproduced by CLP. CLP+DMSO group and CLP+GSK126 group were treated with DMSO or GSK126 (10 mg/kg) respectively right after surgery through intraperitoneal injection. The mice were sacrificed 24 hours after operation, and the mesenteric lymph nodes were collected. The expression of EZH2, apoptosis rates, cell proliferation marker ki-67 antigen positive T lymphocytes (ki-67 + cell), interferon-γ positive T lymphocytes (IFN-γ + cell), programmed death receptor-1 positive T lymphocytes (PD-1 + cell) and programmed death-ligand 1 positive T lymphocytes (PD-L1 + cell) were determined by flow cytometry. Results:Compared with sham operated group, the expression of EZH2 in T lymphocytes was up-regulated on mesenteric lymph nodes of CLP+DMSO group. Compared with CLP+DMSO group, the ratio of CD3 + T lymphocytes in CLP+GSK126 group was up-regulated (0.70±0.02 vs. 0.50±0.07, P < 0.01), indicating that the EZH2 inhibitor could increase the number of T lymphocytes in lymph nodes of septic mice; the ratio of ki-67 + cells in CD4 + and CD8 + T lymphocytes in CLP+GSK126 group was increased (CD4 +: 0.74±0.05 vs. 0.63±0.04, CD8 +: 0.82±0.06 vs. 0.70±0.04, both P < 0.05), indicating that the EZH2 inhibitor could increase the ratio of T lymphocytes with high proliferative activity in lymph nodes of septic mice. However, no significant difference was found on both CD4 + and CD8 + T lymphocytes apoptosis rates in the mesenteric lymph nodes of mice between CLP+GSK126 group and CLP+DMSO group [CD4 +: (21.53±2.87)% vs. (20.48±3.21)%, CD8 +: (8.34±1.02)% vs. (7.71±1.38)%, both P > 0.05], indicating that no extra T lymphocytes apoptosis was induced by EZH2 inhibitor. Compared with CLP+DMSO group, the ratios of IFN-γ + CD4 + and IFN-γ + CD8 + T lymphocytes were increased in CLP+GSK126 group (IFN-γ +CD4 +: 0.31±0.11 vs. 0.14±0.06, IFN-γ +CD8 +: 0.30±0.10 vs. 0.13±0.06, both P < 0.05), suggesting that secretion of IFN-γ in lymph nodes by sepsis T lymphocytes was augmented after EZH2 inhibitor administration. Furthermore, compared with CLP+DMSO group, the ratio of PD-1 + cell in CD8 + T lymphocyte was down-regulated in CLP+GSK126 group (0.092±0.006 vs. 0.135±0.004, P < 0.01), suggesting that EZH2 inhibitor restrained the PD-1 expression on sepsis lymphoid node CD8 + T lymphocytes, however, it had no significant effect on PD-L1 + cells. Conclusion:EZH2, regulates sepsis-induced T lymphocyte dysfunction, possibly through modulating the expression of PD-1.