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ASXL1 is frequently mutated in myeloid malignancies and is known to co-occur with other gene mutations. However, the molecular mechanisms underlying the leukemogenesis associated with ASXL1 and cooperating mutations remain to be elucidated. Here, we report that Asxl1 loss cooperated with haploinsufficiency of Nf1, a negative regulator of the RAS signaling pathway, to accelerate the development of myeloid leukemia in mice. Loss of Asxl1 and Nf1 in hematopoietic stem and progenitor cells resulted in a gain-of-function transcriptional activation of multiple pathways such as MYC, NRAS, and BRD4 that are critical for leukemogenesis. The hyperactive MYC and BRD9 transcription programs were correlated with elevated H3K4 trimethylation at the promoter regions of genes involving these pathways. Furthermore, pharmacological inhibition of both the MAPK pathway and BET bromodomain prevented leukemia initiation and inhibited disease progression in [Asxl.sup.1[DELTA]/[DELTA]][Nf1.sup.[DELTA]1/[DELTA]] mice. Concomitant mutations of ASXL1 and RAS pathway genes were associated with aggressive progression of myeloid malignancies in patients. This study sheds light on the effect of cooperation between epigenetic alterations and signaling pathways on accelerating the progression of myeloid malignancies and provides a rational therapeutic strategy for the treatment of myeloid malignancies with ASXL1 and RAS pathway gene mutations., IntroductionAlteration of epigenetic regulation provides a critical mechanism in the development of myeloid leukemia (1-3). Recent genomic studies have resulted in an emerging understanding of the significance of chromatin regulators [...]

Purpose: The aim of the current study was to investigate factors potentially associated with the healing of infected foot ulcers in patients with diabetes after antimicrobial therapy with drugs selected based on antimicrobial susceptibility testing.Patients and Methods: A retrospective study was conducted to analyze clinical data from 99 type 2 diabetes mellitus patients with foot infection admitted to our center from January 2016 to December 2020. Pathogenic characteristics, results of wound discharge testing, and relevant wound surface factors were analyzed. Etiological characteristics and the results of susceptibility testing, wound healing rates, and factors potentially associated with wound healing rates were also analyzed.Results: Baseline data were analyzed via the t-test for independent samples, the Mann–Whitney U-test, and the chi-square test to identify variables significantly associated with prognosis. Least absolute shrinkage and selection operator regression analysis then determined that Wagner grade, essential hypertension, platelets, Gram negative bacteria, and neutrophil-to-lymphocyte ratio were of predictive value. A nomogram plot was built based on these five variables, and it yielded a standard C-index of 0.964, and an internally corrected C-index of 0.931. In multivariate logistic regression analysis Wagner grade (odds ratio [OR] 12.30, 95% confidence interval [CI] 2.471– 61.194, p = 0.002) and platelet level (OR 0.978, 95% CI 0.960– 0.996, p = 0.018) were significantly associated with wound healing outcomes. Restricted cubic spline analysis indicated that there was a linear relationship between wound healing and platelet levels, and that this relationship was strongest in patients classified as Wagner grade 2 with a platelet count ≤ 200 (p for nonlinearity = 0.442).Conclusion: Wagner grade, essential hypertension, platelet count, Gram negative bacteria, and neutrophil-to-lymphocyte ratio could predict the course of healing of infected foot ulcers in type 2 diabetes mellitus patients. When the Wagner grade was 2 and the platelet level was ≤ 200, platelet level was linearly associated with healing outcome, whereby a lower platelet level predicted a worse wound healing outcome. [ABSTRACT FROM AUTHOR]

Objective To screen mutations in genes including ASXL1, TET2, IDH1, IDH2, SETBP1, MPL515, JAK2 exon 12 and JAK2V617 in 135 polycythemia vera (PV) patients. To assess progreasson and genomics characteristics post polycythemic myelofibrosis. Methods DNA sequencing of ASXL1(Exon12), TET2 (Exons 3- 11), IDH1(Exon4), IDH2(Exon4), SEPBP1(Exon4), JAK2 exon 12 and MPL515 (Exon 10) genes were carried out using Sanger method. JAK2V617 mutation was detected by allele- specific PCR in patients with PV. In the mean time, the mutation load of V617F allele (V617F%) was evaluated by real-time PCR using Tagman MGB probe. Then, the significant of gene mutations and clinical outcomes of post-PV Myelofibrosis (PPMF) was analyzed. To study risk factors of PPMF, logistic regression were employed. Results ASXL1, TET2, IDH1, IDH2 were mutated in 7.69% (8/104), 5.26% (1/19) , 0.08% (1/120) and 0.08% (1/121) of all PV patient respectively. JAK2 was mutated in 82.22% (111/135) of PV patients with mutation rate of exon12 of 2.96% (4/ 135) and there were no mutation of MPL515 and SETBP1 in PV patients. ASXL1 mutation was found in 31.82%(7/22) PPMF patients. Spearman analysis showed that ASXL1 is correlated with JAK2V617F (V617F%) (rs=0.298, P=0.002). The hemoglobin was lower in patients with ASXL1 mutation than patient without mutation (wild type). Leukocyte count, V617F%>50% rate, thrombosis and PPMF were higher in patients with ASXL1 mutation than that of ASXL1 wild type (P<0.05). ASXL1 mutation, V617F%>50% rate and splenomegaly were all risk factors of PPMF. Conclusion ASXL1 mutation is the risk-factor of PPMF and may promote V617F% by some mechanism. [ABSTRACT FROM AUTHOR]

Topramezone is a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor. Due to its broad-spectrum, high efficiency, and low toxicity, topramezone is a candidate herbicide for the construction of genetically modified (GM) herbicide-resistant crops. In the present study, we screened a topramezone-resistant isolate Sphingobium sp. TPM-19 and cloned a topramezone-resistant HPPD gene ( SphppD ) from this isolate. Sp HPPD shared the highest similarity (53%) with an HPPD from Vibrio vulnificus CMCP6. Sp HPPD was synthesized in Escherichia coli BL21(DE3) and purified to homogeneity using Co 2+ -affinity chromatography. Sp HPPD was found to be a monomer. The K m and k cat of Sp HPPD for 4-hydroxyphenylpyruvate (4-HPP) were 82.8 μM and 15.0 s -1 , respectively. Sp HPPD showed high resistance to topramezone with half maximal inhibitory concentration (IC 50 ) and K i values of 5.2 and 2.5 μM, respectively. Additionally, Sp HPPD also showed high resistance to isoxaflutole (DKN) (IC 50 : 8.7 μM; K i : 6.0 μM) and mesotrione (IC 50 : 4.2 μM; K i : 1.3 μM) and moderate resistance to tembotrione (IC 50 : 2.5 μM; K i : 1.0 μM). The introduction of the SphppD gene into Arabidopsis thaliana enhanced obvious resistance against topramezone. In conclusion, this study provides a novel topramezone-resistant HPPD gene for the genetic engineering of GM herbicide-resistant crops.

Esterase SulE detoxicates a variety of sulfonylurea herbicides through de-esterification. SulE exhibits high activity against thifensulfuron-methyl but low activity against other sulfonylureas. In this study, two variants, m2311 (P80R) and m0569 (P80R and G176A), with improved activity were screened from a mutation library constructed by error-prone PCR. Variant m2311 showed a higher activity against sulfonylureas in comparison variant m0569 and was further investigated. The k cat / K m value of variant m2311 for metsulfuron-methyl, sulfometuron-methyl, chlorimuron-ethyl, tribenuron-methyl, and ethametsulfuron-methyl increased by 3.20-, 1.72-, 2.94-, 2.26- and 2.96-fold, respectively, in comparison with the wild type. Molecular modeling suggested that the activity improvement of variant m2311 is due to the substitution of Pro80 by arginine, leading to the formation of new hydrogen bonds between the enzyme and substrate. This study facilitates further elucidation of the structure and function of SulE and provides an improved gene resource for the detoxification of sulfonylurea residues and the genetic engineering of sulfonylurea-resistant crops.

Objective: To explore the survival and the risk factors of poor prognosis in Chinese patients with polycythemia vera (PV)., Methods: A total of 816 patients with a definite diagnosis of PV were enrolled from August 1983 to June 2013 into this study. The standardized mortality ratio (SMR) was calculated by comparing the cumulative survival of 816 PV patients with age- and sex- and calendar year-matched healthy Chinese population from the national bureau of statistics of the People's Republic of China. The clinical features of diagnosis and prognosis of PV patients were analyzed by Cox regression to identify risk factors for the poor prognosis of PV and to develop a dynamic prognostic model in Chinese patients. The effects of different treatments on the development of acute myelocytic leukemia (AML) and post-PV myelofibrosis (post-PV MF) were determined by Kaplan-Meier analysis. JAK2 V617F allele burden (V617F%) was determined by quantitative real-time PCR in 104 patients., Results: The median follow-up time was 6 (1-42) years. The 10-, 15- and 20-year overall survival (OS) was 89.50%, 76.70% and 64.70%, respectively. The SMR was 17.40 (95% CI: 13.71-21.78). Cox regression analysis revealed that white blood cell (WBC) count>10×10(9)/L (HR=3.10, 95% CI: 1.47-6.53, P=0.003), age>60 years (HR=2.89, 95% CI: 1.84-4.53, P<0.001) and prior thrombosis (HR=2.66, 95% CI: 1.65-4.29, P<0.001) were significant predictors for the poor prognosis of PV. Based on the hazard radio, 816 patents were allocated into 4 categories with significantly different survival: low (sum of points=0; median survival no reached), intermediate 1 (sum of points=1; median survival 33.10 (28.20-38.00) years), intermediate 2 (sum of points=2; median survival 23.00 (16.08-29.92) years), high (sum of points=3; median survival 13.00 (10.58-15.42) years). The mortality of high risk group was 5.37 fold higher than low risk patients. The 10- and 20-year survival of no post-PV MF were 89.50% and 79.60%, respectively, for interferon α (IFN-α); 73.80% and 43.50%, respectively, for hydroxyurea treatment; 82.20% and 71.40%, respectively, for alkylating agent treatment; and 80.00% and 38.20%, respectively, for no cytoreductive treatment. The treatment of exposure to IFN-α associated with a higher rate of no-post-PV MF survival (Log-rank=9.79, P=0.020). There were more post-PV MF patients with V617F%≥50% compared with those V617F%<50% (P<0.001)., Conclusions: The mortality of PV patients is significantly higher than that of healthy Chinese population. The WBC count>10×10(9)/L, age>60 years, and prior thrombosis are identified as significant predictors for the prognosis of PV. The risk of post-PV MF transformation may be ameliorated by IFN-α via decreasing the burden of JAK2 V617F mutation.