The engagement of histone lysine methyltransferases with nucleosomes: structural basis, regulatory mechanisms, and therapeutic implications

Histone lysine methyltransferases (HKMTs) deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression. The structures and functions of HKMTs have been extensively investigated in recent decades, significantly advancing our understanding of the dynamic regulation of histone methylation. Here, we review the recent progress in structural studies of representative HKMTs in complex with nucleosomes (H3K4, H3K27, H3K36, H3K79, and H4K20 methyltransferases), with emphasis on the molecular mechanisms of nucleosome recognition and trans-histone crosstalk by these HKMTs. These structural studies inform HKMTs' roles in tumorigenesis and provide the foundations for developing new therapeutic approaches targeting HKMTs in cancers.

Analysis of NSD1 gene variant in a child with autism spectrum disorder in conjunct with congenital heart disease / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic basis of a child with autism spectrum disorder (ASD) in conjunct with congenital heart disease (CHD).@*METHODS@#A child who was hospitalized at the Third People's Hospital of Chengdu on April 13, 2021 was selected as the study subject. Clinical data of the child were collected. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). A GTX genetic analysis system was used to analyze the WES data and screen candidate variants for ASD. Candidate variant was verified by Sanger sequencing and bioinformatics analysis. Real-time fluorescent quantitative PCR (qPCR) was carried out to compare the expression of mRNA of the NSD1 gene between this child and 3 healthy controls and 5 other children with ASD.@*RESULTS@#The patient, an 8-year-old male, has manifested with ASD, mental retardation and CHD. WES analysis revealed that he has harbored a heterozygous c.3385+2T>C variant in the NSD1 gene, which may affect the function of its protein product. Sanger sequencing showed that neither of his parent has carried the same variant. By bioinformatic analysis, the variant has not been recorded in the ESP, 1000 Genomes and ExAC databases. Analysis with Mutation Taster online software indicated it to be disease causing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic. By qPCR analysis, the expression level of mRNA of the NSD1 gene in this child and 5 other children with ASD was significantly lower than that of the healthy controls (P < 0.001).@*CONCLUSION@#The c.3385+2T>C variant of the NSD1 gene can significantly reduce its expression, which may predispose to ASD. Above finding has enriched the mutational spectrum the NSD1 gene.

Research Progress of Role and Mechanism of SETD7 in Tumor Occurrence and Progression / 中国肺癌杂志

The occurence and development of tumors is a complicated process, which not only depends on the mutation or deletion of genes, but also is affected by epigenetic regulation. Accumulating evidences have shown that epigenetic modifications play fundamental roles in transcriptional regulation, heterochromatin formation, X chromosome inactivation, DNA damage response and tumor development. SET domain containing lysine methyltransferase 7 (SETD7) was initially identified as an important lysine methyltransferase, which methylated histone and non-histone proteins. These modifications play fundamental roles. Once this modification disorders, it can directly lead to cell abnormalities and cause many diseases. Studies have shown that SETD7 is related to the occurence and development of various tumors, but the methylation sites of SETD7 and its regulatory mechanism have not been fully elucidated. This article summarizes the research progress of the role of SETD7 on histone and non-histone methylation modification in tumors and the molecular mechanism, in order to provide new therapeutic targets for tumor pathogenesis and diagnosis.
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SET8 Inhibition Potentiates Radiotherapy by Suppressing DNA Damage Repair in Carcinomas / 生物医学与环境科学（英文）

Objective@#SET8 is a member of the SET domain-containing family and the only known lysine methyltransferase (KMT) that monomethylates lysine 20 of histone H4 (H4K20me1). SET8 has been implicated in many essential cellular processes, including cell cycle regulation, DNA replication, DNA damage response, and carcinogenesis. There is no conclusive evidence, however, regarding the effect of SET8 on radiotherapy. In the current study we determined the efficacy of SET8 inhibition on radiotherapy of tumors and the underlying mechanism.@*Methods@#First, we explored the radiotherapy benefit of the SET8 expression signature by analyzing clinical data. Then, we measured a series of biological endpoints, including the xenograft tumor growth in mice and apoptosis, frequency of micronuclei, and foci of 53BP1 and γ-H2AX in cells to detect the SET8 effects on radiosensitivity. RNA sequencing and subsequent experiments were exploited to verify the mechanism underlying the SET8 effects on radiotherapy.@*Results@#Low expression of SET8 predicted a better benefit to radiotherapy in lung adenocarcinoma (LUAD) and invasive breast carcinoma (BRCA) patients. Furthermore, genetic deletion of SET8 significantly enhanced radiation treatment efficacy in a murine tumor model, and A549 and MCF7 cells; SET8 overexpression decreased the radiosensitivity. SET8 inhibition induced more apoptosis, the frequency of micronuclei, and blocked the kinetics process of DNA damage repair as 53BP1 and γ-H2AX foci remained in cells. Moreover, RNF8 was positively correlated with the SET8 impact on DNA damage repair.@*Conclusion@#Our results demonstrated that SET8 inhibition enhanced radiosensitivity by suppressing DNA damage repair, thus suggesting that SET8 potentiated radiotherapy of carcinomas. As new inhibitors of SET8 are synthesized and tested in preclinical and clinical settings, combining SET8 inhibitors with radiation warrants consideration for precise radiotherapy.

Analysis of gene variation and clinical characteristics of Wiedemann-Steiner syndrome / 中华儿科杂志

Objective: To summarize and analyze the clinical characteristics and gene mutations of 6 patients with Wiedemann-Steiner syndrome (WDSTS). Methods: To review and analyze the clinical data, including general conditions, clinical manifestations, growth hormone, cranial or pituitary gland magnetic resonance imaging (MRI),gene results and other data, 6 cases with WDSTS admitted to the Department of Endocrinology, Genetics and Metabolism of Jiangxi Provincial Children's Hospital and the Department of Child Care of Pingxiang Maternity and Child Care from April 2017 to February 2021 were recruited. Results: Of the 6 patients, 2 were male and 4 were female. The age of the first visit ranged from 1.0 to 11.2 years. All the 6 children presented with growth retardation and mental retardation and they all had typical facial dysmorphism and hypertrichosis (mainly on the back and limbs). Among them, case 5 had a growth hormone deficiency, and case 2 and 4 had abnormalities revealed by cranial MRI. Variations in KMT2A gene were identified in these 6 patients: c.10900+2T>C,c.10837C>T(p.Gln3613*), c.4332G>A(p.E1444E), c.2508dupC(p.W838Lfs*9), c.11695_11696delinsT(p.T3899Sfs*73), c.9915dupA (p.P3306Tfs*22).Among these variations, c.4332G>A, c.11695_11696delinsT and c.9915dupA were novel mutations. Therefore, the final diagnosis of these patients was WDSTS. Conclusions: Patients presented with short stature and mental retardation, typical facial dysmorphism and hypertrichosis should be considered WDSTS. Whole-exome sequencing plays an important role in disease diagnosis and genetic counseling.

miR-140-3p enhanced the osteo/odontogenic differentiation of DPSCs via inhibiting KMT5B under hypoxia condition / 国际口腔科学杂志·英文版

Human dental pulp stem cells (DPSCs) have emerged as an important source of stem cells in the tissue engineering, and hypoxia will change various innate characteristics of DPSCs and then affect dental tissue regeneration. Nevertheless, little is known about the complicated molecular mechanisms. In this study, we aimed to investigate the influence and mechanism of miR-140-3p on DPSCs under hypoxia condition. Hypoxia was induced in DPSCs by Cobalt chloride (CoCl

Wiedemann-Steiner syndrome due to novel nonsense variant of KMT2A gene in a case / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with unexplained global developmental delay (GDD), seizure, and facial deformity.@*METHODS@#Whole exome sequencing (WES) was carried out for the patient. Candidate variants were verified by Sanger sequencing of the patient and his parents.@*RESULTS@#WES revealed that the patient has carried a previously unreported de novo heterozygous nonsense c.4906C>T (p.Arg1636Ter) variant of the KMT2A gene, Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.4906C>T variant of KMT2A gene was predicted to be pathogenic (PVS1+ PS2+ PM2+PP3).@*CONCLUSION@#The heterozygous nonsense c.4906C>T (p.Arg1636Ter) variant of the KMT2A gene probably underlay the disease in the child. Above finding has enriched the spectrum of pathogenic variants of the KMT2A gene.

Clinical characteristics and prognostic analysis of pediatric pro-B cell acute lymphoblastic leukemia / 中国当代儿科杂志

OBJECTIVE@#To explore the clinical-biological characteristics and prognosis of pediatric pro-B cell acute lymphoblastic leukemia (pro-B-ALL).@*METHODS@#A total of 64 patients aged less than 18 years old with pro-BALL were enrolled. Clinical characteristics, therapeutic effect and prognostic factors were retrospectively analyzed.@*RESULTS@#Pro-B-ALL occurred in 6.23% (64/1 028) of pediatric ALL. Among the 64 patients, 35 were male and 29 were female. The median age was 7.0 years (range 0.4-16.0 years) at diagnosis, of which 39% and 6% were ≥ 10 years old and < 1 year old respectively. The median WBC count was 25.5×10@*CONCLUSIONS@#Pediatric pro-B ALL is a heterogeneous disease with clinical and biological diversity. Biological characteristics, such as immunological markers, genetic alterations, and MRD at 3 months after chemotherapy may be important factors for the long-term prognosis.

Genome-wide DNA methylation profile in the peripheral blood of cocaine and crack dependents

Objective: Cocaine use disorders (CUDs) represent a major public health problem in many countries. To better understand the interaction between the environmental modulations and phenotype, the aim of the present study was to investigate the DNA methylation pattern of CUD patients, who had concomitant cocaine and crack dependence, and healthy controls. Methods: We studied DNA methylation profiles in the peripheral blood of 23 CUD patients and 24 healthy control subjects using the Illumina Infinium HumanMethylation450 BeadChip arrays. Results: Comparison between CUD patients and controls revealed 186 differentially methylated positions (DMPs; adjusted p-value [adjP] < 10-5) related to 152 genes, with a subset of CpGs confirmed by pyrosequencing. DNA methylation patterns discriminated CUD patients and control groups. A gene network approach showed that the EHMT1, EHMT2, MAPK1, MAPK3, MAP2K1, and HDAC5 genes, which are involved in transcription and chromatin regulation cellular signaling pathways, were also associated with cocaine dependence. Conclusion: The investigation of DNA methylation patterns may contribute to a better understanding of the biological mechanisms involved in CUD.

Wiedemann-Steiner syndrome with a novel pathogenic variant in KMT2A: a case report / Síndrome de Wiedemann-Steiner por una nueva variante patogénica en KMT2A: reporte de un caso

Abstract Case Description: We report the case of a one-year-old girl who was diagnosed with Wiedemann-Steiner Syndrome based on the identification of a novel de novo frameshift mutation in the KMT2A gene by whole exome sequencing and supported by her clinical features. Clinical Findings: KMT2A mutations cause Wiedemann-Steiner Syndrome, a very rare genetic disorder characterized by congenital hypertrichosis, short stature, intellectual disability, and distinct facial features. Treatment and Outcome: Whole exome sequencing identified a novel frameshift variant: c. 4177dupA (p.Ile1393Asnfs * 14) in KMT2A; this change generates an alteration of the specific binding to non-methylated CpG motifs of the DNA to the protein. The genotype and phenotype of the patient were compared with those of earlier reported patients in the literature. Clinical Relevance: In diseases with low frequency, it is necessary to establish a genotype-phenotype correlation that allows the establishment of therapeutic and follow-up goals. The phenotype comparation with other reported cases did not show differences attributable to sex or age among patients with Wiedemann-Steiner Syndrome. Whole exome sequencing allows identifying causality in conditions with high clinical and genetic heterogeneity like hypertrichosis.

Resumen Descripción del caso: Se reporta el caso de una paciente femenina de un año de edad, diagnosticada con Síndrome de Wiedemann-Steiner basado en la identificación de una nueva variante patogénica de novo de tipo frameshift en el gen KMT2A Mediante secuenciación de exoma usando el enfoque de trio, sumado a sus características clínicas. Hallazgos clínicos: las mutaciones en KMT2A causan el Síndrome de Wiedemann-Steiner, un desorden genético muy raro caracterizado por hipertricosis congénita, talla baja, retardo mental variable y fenotipo facial distintivo, los cuales se encuentran en la paciente reportada. Resultado: La Secuenciación de exoma completo encontró una variante de tipo frameshift: c.4177dupA (p. Ile1393Asnfs * 14) en KMT2A, este cambio a nivel génico genera una alteración de la unión específica a motivos CpG no metilados del DNA a la proteína. El genotipo y el fenotipo de la paciente fue comparado con los pacientes reportados previamente en la literatura. Relevancia clínica: En enfermedades con baja frecuencia como la aquí reportada es necesario establecer correlaciones genotipo-fenotipo que permitan establecer planes terapéuticos y de seguimiento. El análisis realizado no evidenció diferencias atribuibles a sexo o edad entre los pacientes diagnosticados con Síndrome de Weidemann-Steiner. La secuenciación de exoma permitió identificar causalidad en este caso, cuya característica principal de hipertricosis se asocia con alta heterogeneidad clínica y genética.

Comprehensive Cancer Panel Sequencing Defines Genetic Diversity and Changes in the Mutational Characteristics of Pancreatic Cancer Patients Receiving Neoadjuvant Treatment

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDA) is associated with an extremely poor prognosis. This study assessed the genetic diversity among patients with PDA and compared their mutational profiles before and after treatment. METHODS: Tumors and matched blood samples were obtained from 22 PDA patients treated with neoadjuvant chemoradiation therapy. The somatic mutations were analyzed with comprehensive cancer gene panel (CCP). In addition, the biopsy samples obtained at diagnosis and the surgically resected samples after treatment were compared for seven patients. The CCP provided formalin-fixed paraffin-embedded sample-compatible multiplexed target selection for 409 genes implicated in cancer. RESULTS: Assessments of the MLH1, MLH3, MSH2, and PMS2 genes showed that the four patients with the highest relative burdens of mutations harbored somatic mutations in at least three of these genes. Genes in the histone-lysine N-methyltransferase 2 (KMT2) family, such as KMT2D, KMT2A, and KMT2C, were frequently mutated in tumor samples. Survival was worse in patients with ARID1A gene mutations than those without ARID1A gene mutations. Mutation patterns were compared between tissue samples before and after neoadjuvant treatment in seven patients who underwent surgical resection. The allelic fraction of mutations in KRAS codon 12 was lower in the surgically resected samples than in the endoscopic ultrasonography-guided fine needle aspiration biopsy samples of six patients. The number of mutant alleles of the histone lysine methyltransferase gene WHSC1 also decreased after treatment. CONCLUSIONS: These results indicate that tumor tissue from PDA patients is genetically diverse and suggest that ARID1A mutations may be a potential prognostic marker for PDA.

Downregulation of SIRT2 by Chronic Stress Reduces Expression of Synaptic Plasticity-related Genes through the Upregulation of Ehmt2

Silent information regulator 2 (Sirtuin2 / SIRT2) is a NAD⁺-dependent deacetylase that regulates the cellular oxidative stress response. It modulates transcriptional silencing and protein stability through deacetylation of target proteins including histones. Previous studies have shown that SIRT2 plays a role in mood disorders and hippocampus-dependent cognitive function, but the underlying neurobiological mechanism is poorly understood. Here, we report that chronic stress suppresses SIRT2 expression in the hippocampus. Molecular and biochemical analyses indicate that the stress-induced decrease in the SIRT2 expression downregulates synaptic plasticity-related genes in the hippocampus through the increase of euchromatic histone-lysine N-methyltransferase 2 (Ehmt2) (also known as G9a). shRNA-mediated knockdown of SIRT2 in the dentate gyrus alters the expression of synaptic plasticity-related genes in a way similar to those induced by chronic stress, and produces depression-like behaviors. Our results indicate that SIRT2 plays an important role in the response to stress, thereby modulating depression-like behaviors.

The anti-proliferative and anti-inflammatory mechanisms of JAK1 inhibitor SHR0302 versus Ruxolitinib in SET2 cell line and primary cells / 中华血液学杂志

Objective: To explore the effects and molecular mechanism of the selective JAK1inhibitor SHR0302 and Ruxolitinib on myeloproliterative neoplasms (MPN) cell line SET2 and primary cells in vitro. Methods: Cell proliferation was detected by CCK8 kit. Colony forming experiment was conducted to evaluate erythroid burst colony formation unit (BFU-E) of primary cells from MPN patients. Multi-factor kits were used to detect six inflammatory cytokines. Phosphorylated proteins of Jak-Stat signaling pathway were tested by Western blot. Results: At different time points after treated with SHR0302 and Ruxolitinib, the inhibition of cell proliferation was dose dependent by both drugs (P<0.01) . The inhibitory rates of 2.5 μmol/L SHR0302 and 0.1 μmol/L Ruxolitinib on SET2 cells for 72 h were comparable, i.e. (59.94±0.60) % and (64.00±0.66) %, respectively, suggesting that the inhibitory effect of SHR0302 was weaker than that of Ruxolitinib. Similarly, both SHR0302 and Ruxolitinib inhibited BFU-E in primary marrow cells from MPN patients in a dose-dependent manner. SHR0302 1.0 μmol/L produced similar degree of inhibition compared to Ruxolitinib 0.2 μmol/L. Except IL-12, the expression of other 5 cytokines (IL-6, TNF-α, IL-1β, IL-2, IL-8) was significantly inhibited by 1.6 μmol/L SHR0302 in SET2 cells at 24 h (P<0.01) , while Ruxolitinib 1.0 μmol/L had the same effect. Several phosphorylated molecules of Jak-Stat signaling pathway were significantly inhibited by SHR0302 in SET2 cells only for 3 h. P-stat1 (Tyr701) , p-stat3 (Tyr705) were down-regulated when treated with SHR0302 1.0 μmol/L (P<0.05) , p-jak1 (tyr1022/1023) and p-stat5 (Tyr694) were inhibited at 5.0 μmol/L (P<0.05) . Ruxolitinib significantly inhibited the downstream STAT protein at 0.1 μmol/L. Again, the inhibitory effect of SHR0302 on protein expression was weaker than that of Ruxolitinib. Conclusion: SHR0302 can effectively inhibit the proliferation of MPN cell line and patients' primary cells, as well as the expression of inflammatory factors. The molecular mechanism is possibly related to the down-regulation of phosphorylated proteins of Jak-Stat signaling pathway. Overall, the anti-proliferative and anti-inflammatory effects of SHR0302 are weaker than those of Ruxolitinib.

Research progress of histone 3 methyltransferase MLL4 / 生理学报

Mixed linked leukemia 4 (MLL4) is a specific methyltransferase of histone 3 position lysine 4 (H3K4). It is also one of the important members of COMPASS/Set1-like protein complex. Both MLL4 protein itself and its mediated H3K4 methylation modification can cause changes in chromatin structure and function, thus regulating gene transcription and expression. With the studies of MLL4 protein in recent years, the roles of MLL4 gene, MLL4 protein and protein complex in the development of tissues and organs, tumor diseases and other physiological and pathophysiological processes have been gradually revealed. In this paper, the research progress of MLL4 gene, MLL4 protein characteristics, biological function and its effect on disease were reviewed, in order to further understand the effect of histone methyltransferase on gene expression regulation, as well as its non-enzyme dependent function. This paper may provide new ideas for the prevention, diagnosis and treatment of related diseases.

The value of detecting MLL gene rearrangement in children with acute monocytic leukemia / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of detecting the rearrangement of mixed lineage leukemia (MLL) gene in children with acute mononuclear leukemia (AML).@*METHODS@#Dual-color fluorescence in situ hybridization (FISH) probe was used to detect MLL gene rearrangement in 68 children with AML by interphase FISH. The results were compared with that of conventional G banding chromosomal analysis.@*RESULTS@#Among the 68 children, 28 were detected by FISH with positive hybridization signals, with a detection rate for MLL gene rearrangement being 41.2%. Twelve (17.6%) reciprocal translocations and interruption of 11q23 were detected by G banding analysis. The difference in the detection rates between the two methods was statistically significant (P< 0.05).@*CONCLUSION@#The sensitivity of FISH assay for MLL gene rearrangement was significantly higher than that of G banding chromosomal karyotyping. Combined use of both methods for children with AML can improve the detection rate of MLL gene rearrangements and provide crucial clues for clinical diagnosis, treatment and prognosis.

Application of multiple MLL gene rearrangement detection techniques for children with acute mononuclear leukemia / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of detecting multiple rearrangements of MLL gene in children with acute mononuclear leukemia (AML).@*METHODS@#Eighty six children with AML were analyzed by fluorescence in situ hybridization (FISH), chromosomal karyotyping and multiplex reverse transcription-PCR (RT-PCR).@*RESULTS@#Cross signals were detected by FISH in 26 cases, and 30.2% were detected with MLL gene rearrangements. R-band karyotyping analysis revealed 14 translocations with breakages involving 11q23 and 5 other aberrations, which yielded an overall detection rate of 22.1%. Multiple RT-PCR has detected 12 fusion genes produced by the MLL translocation, which yielded a detection rate of 14.0%. A significant difference was found in the detection rate of the three methods (P< 0.05).@*CONCLUSION@#Combined use of FISH, chromosomal karyotyping and multiplex RT-PCR can improve the detection of MLL gene rearrangements and provide important clues for clinical diagnosis, treatment and prognosis of AML.

Clinical characteristics and prognosis of 34 cases of acute myeloid leukemia with FLT3 internal tandem duplication and MLL gene rearrangement / 中华血液学杂志

Objective: To analyze the clinical characteristics and prognosis of 34 cases of acute myeloid leukemia (AML) with FLT3 internal tandem duplication (FLT3-ITD) and MLL gene rearrangement. Methods: The clinical data of 34 AML patients with FLT3-ITD and MLL gene rearrangement was compared and analyzed for the therapeutic efficacy, prognostic factors when treated with chemotherapy, chemotherapy combined with targeted therapy or allogenic hematopoietic stem cell transplantation (allo-HSCT). Results: Of the thirty-four cases with median age 41 (4-71) years old, 63.6% presented with white blood cells (WBC) greater than 30×10(9)/L, 39.4% greater than 50 × 10(9)/L respectively on admission. M(5) (35.3%) made up the highest proportion. The cytogenetic abnormality reached 61.8%, of which the complex cytogenetic abnormality accounted for 11.8%. Eleven patients (32.35%) had both FLT3-ITD and MLL gene abnormalities. In addition to FLT3 and MLL abnormalities, 23 patients (67.6%) had one or more other gene abnormalities (multiple gene abnormalities). Of the 34 cases, 29.4% patients went into complete remission (CR) after two courses of chemotherapy. 20.6% (7 patients) went into CR after 3 or more courses of chemotherapy. The rate of early relapse in the CR group was 52.9%. Patients with WBC>50×10(9)/L or multiple gene abnormalities had a lower remission rate (7.7%, 5.4%) after two courses of chemotherapy. CR rate for the patients with more than three gene abnormalities was 0. The total 2-year overall survival (OS) in the 34 patients was 28.8% (95% CI 13.5%-46.0%) and the disease-free survival (DFS) was 27.1% (95% CI 12.5%-44.0%). Of the 18 patients treated with chemotherapy alone or chemotherapy combined with targeted therapy, 17 cases died within 2 years and 1 lost follow-up after giving up treatment. For the 16 patients received allo-HSCT, the 3-year OS was 43.4% (95% CI 13.7%-70.4%) and DFS 42.7% (95% CI 13.4%-69.7%). Conclusion: AML patients with FLT3-ITD and MLL gene rearrangement often presented with M(5), accompanied by hyperleukocytosis, cytogenetic or multiple gene abnormalities. Those patients were observed to have low response rate and high early relapse when treated with chemotherapy without allo-HSCT. Patients had multiple gene abnormalities may be an important poor prognostic factor. Allo-HSCT is an effective treatment which could significantly improve the prognosis and survival of AML patients with FLT3-ITD and MLL gene abnormalities.

Prognostic analysis of allogeneic hematopoietic stem-cell transplantation in 47 patients with acute myeloid leukemia and MLL rearrangement / 中华血液学杂志

Objective: To investigate the prognosis of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) for patients with acute myeloid leukemia and MLL rearrangement. Methods: From September 2009 to May 2016, the clinical data of 47 patients with MLL-rearranged AML undergoing allo-HSCT in the First Affiliated Hospital of Soochow University were retrospectively analyzed. Results: Among 47 MLL-rearranged AML patients, 24 were male and 23 female. The median age was 30 (15-58) years old. There are 36 (76%) patients were FAB-types M4/M5. Two-year overall survival (OS), disease-free survival (DFS), relapse incidence and transplant-related mortality (TRM) were (64.4±8.4)%, (47.3±9.3)%, 41.0% and 17.9%, respectively. Of them, 45 patients were detected with 11q23 translocations, and 2 patients with normal karyotype were MLL partial tandem duplication. According to different chromosome karyotype, 47 patients were divided into three groups: 16 cases of t (6; 11), 15 cases of t (9; 11) and 16 cases of other types. Overall survival was compared between the three groups, there was no significant difference (χ(2)=1.509, P=0.472). On multivariate analysis, independent risk factor on OS was transplant age >45 years [HR=4.454(95%CI 1.314-15.099), P=0.016]. The multivariate analysis also confirmed the higher TRM in patients at non-CR state when transplanted [HR=10.370(95%CI 1.043-103.110), P=0.046]. Positive minimal residual disease (MRD) before transplantation was a negative prognostic factor on DFS [HR=4.236(95%CI 1.238-14.495), P=0.021] and relapse incidence (RI) [HR=5.491(95%CI 1.371-21.995), P=0.016]. Conclusion: Transplant age (>45 years), allo-HSCT in non-CR state adn positive MRD before transplantation were negative prognostic factors in allo-HSCT for MLL-rearranged AML patients.

Characteristics and prognosis in adult acute myeloid leukemia patients with MLL gene rearrangements / 中华血液学杂志

Objective: To analyze the clinical and laboratory characteristics, and prognosis of adult acute myeloid leukemia (AML) patients with MLL gene rearrangements. Methods: The medical records of 92 adult AML patients with MLL gene rearrangements from January 2010 to December 2016 were retrospectively analyzed. Results: 92 cases (6.5%) with MLL gene rearrangements were identified in 1 417 adult AML (Non-M(3)) patients, the median age of the patients was 35.5 years (15 to 64 years old) with an equal sex ratio, the median WBC were 21.00(0.42-404.76)×10(9)/L, and 78 patients (84.8%) were acute monoblastic leukemia according to FAB classification. Eleven common partner genes were detected in 32 patients, 9 cases (28.1%) were MLL/AF9(+), 5 cases (15.6%) were MLL/AF6(+), 5 cases (15.6%) were MLL/ELL(+), 2 cases (6.3%) were MLL/AF10(+), 1 case (3.1%) was MLL/SETP6(+), and the remaining 10 patients' partner genes weren't identified. Of 92 patients, 83 cases with a median follow-up of 10.3 (0.3-74.0) months were included for the prognosis analysis, the complete remission (CR) rate was 85.5% (71/83), the median overall survival (OS) and relapse free survival (RFS) were 15.4 and 13.1 months, respectively. Two-year OS and RFS were 36.6% and 29.5%, respectively. Of 31 patients underwent allogeneic hematopoietic stem-cell transplantation (allo-HSCT), two-year OS and RFS for patients received and non-received allo-HSCT were 57.9% and 21.4%, 52.7% and 14.9%, respectively (P<0.001). Among patients with partner genes tested, 9 of 32 cases (28.1%) were MLL/AF9(+), the median follow-up was 6.0(4.1-20.7) months. 3 patients with MLL/AF9 underwent allo-HSCT. 23 cases (71.9%) were non- MLL/AF9(+), the median follow-up was 7.8 (0.3-26.6) months. 14 patients (60.1%) with non-MLL/AF9 underwent allo-HSCT. One-year OS for patients with MLL/AF9 and non-MLL/AF9 were 38.1% and 55.5%, respectively (P=0.688). Multivariate analysis revealed that high WBC (RR=1.825, 95% CI 1.022-3.259, P=0.042), one cycle to achieve CR (RR=0.130, 95% CI 0.063-0.267, P<0.001), post-remission treatment with allo-HSCT (RR=0.169, 95% CI 0.079-0.362, P<0.001) were independent prognostic factors affecting OS. Conclusions: AML with MLL gene rearrangements was closely associated with monocytic differentiation, and MLL/AF9 was the most frequent partner gene. Conventional chemotherapy produced a high response rate, but likely to relapse, allo-HSCT may have the potential to further improve the prognosis of this group of patients.

Links between Serine Biosynthesis Pathway and Epigenetics in Cancer Metabolism

Cancer metabolism is considered as one of major cancer hallmarks. It is important to understand cancer-specific metabolic changes and its impact on cancer biology to identify therapeutic potentials. Among cancer-specific metabolic changes, a role of serine metabolism has been discovered in various cancer types. Upregulation of serine synthesis pathway (SSP) supports cell proliferation and metastasis. The change of serine metabolism is, in part, mediated by epigenetic modifiers, such as Euchromatic histone-lysine N-methyltransferase 2 and Lysine Demethylase 4C. On the other hand, SSP also influences epigenetic landscape such as methylation status of nucleic acids and histone proteins via affecting S-adenosyl methionine production. In the review, we highlight recent evidences on interactions between SSP and epigenetic regulation in cancer. It may provide an insight on roles and regulation of SSP in cancer metabolism and the potential of serine metabolism for cancer therapy.