Oncogene Function in Pre-Leukemia Stage of INV(16) Acute Myeloid Leukemia: A Dissertation

The CBFbeta-SMMHC fusion protein is expressed in acute myeloid leukemia (AML) samples with the chromosome inversion inv(16)(p13;q22). This fusion protein binds the transcription factor RUNX with higher affinity than its physiological partner CBFbeta and disrupts the core binding factor (CBF) activity in hematopoietic stem and progenitor cells. Studies in the Castilla laboratory have shown that CBFbeta-SMMHC expression blocks differentiation of hematopoietic progenitors, creating a pre-leukemic progenitor that progresses to AML in cooperation with other mutations. However, the combined function of cumulative cooperating mutations in the pre-leukemic progenitor cells that enhance their expansion to induce leukemia is not known. The standard treatment for inv(16) AML is based on the use of non-selective cytotoxic chemotherapy, resulting in a good initial response, but with limited long-term survival. Therefore, there is a need for developing targeted therapies with improved efficacy in leukemic cells and minimal toxicity for normal cells. Here, we used conditional Nras+/LSL-G12D; Cbfb+/56M; Mx1Cre knock-in mice to show that allelic expression of oncogenic N-RasG12D expanded the multi-potential progenitor (MPP) compartment by 8 fold. Allelic expression of Cbfbeta-SMMHC increased the MPPs and short-term hematopoietic stem cells (ST-HSCs) by 2 to 4 fold both alone and in combination with N-RasG12D expression. In addition, allelic expression of oncogenic N-RasG12D and Cbfbeta-SMMHC increases survival of pre-leukemic stem and progenitor cells. Differential analysis of bone marrow cells determined that Cbfb+/MYH11 and Nras+/G12D; vii Cbfb+/MYH11 cells included increased number of blasts, myeloblasts and promyelocytes and a reduction in immature granulocytes, suggesting that expression of N-RasG12D cannot bypass Cbfbeta-SMMHC driven differentiation block. N-RasG12D and Cbfbeta-SMMHC synergized in leukemia, in which Nras+/G12D; Cbfb+/MYH11 mice have a shorter median latency than Cbfb+/MYH11 mice. In addition, the synergy in leukemogenesis was cell autonomous. Notably, leukemic cells expressing N-RasG12D and Cbfbeta-SMMHC showed higher (over 100 fold) leukemia-initiating cell activity in vivo than leukemic cells expressing Cbfbeta-SMMHC (L-IC activity of 1/4,000 and 1/528,334, respectively). Short term culture and biochemical assays revealed that pre-leukemic and leukemic cells expressing N-RasG12D and Cbfbeta-SMMHC have reduced levels of pro-apoptotic protein Bim compared to control. The Nras+/G12D; CbfbMYH11 pre-leukemic and leukemic cells were sensitive to pharmacologic inhibition of MEK/ERK signaling pathway with increasing apoptosis and Bim protein levels but not sensitive to PI3K inhibitors. In addition, knock-down of Bcl2l11 (Bim) expression in Cbfbeta-SMMHC pre-leukemic progenitors decreased their apoptosis levels. In collaboration with Dr. John Bushweller’s and other research laboratories, we recently developed a CBFbeta-SMMHC inhibitor named AI-10-49, which specifically binds to CBFbeta-SMMHC, prevents its binding to RUNX proteins and restores CBF function. Biochemical analysis in human leukemic cells showed that AI-10-49 has significant specificity in reducing the viability of leukemic cells expressing CBFbeta-SMMHC (IC50= 0.83μM), and negligible toxicity in normal cells. Likewise, mouse Nras+/G12D; viii Cbfb+/MYH11 leukemic cells were sensitive to AI-10-49 (IC50= 0.93μM). By using the NrasLSL-G12D; Cbfb56M mouse model, we also show that AI-10-49 significantly prolongs the survival of mice bearing the leukemic cells. Preliminary mechanistic analysis of AI-10-49 activity has shown that AI-10-49 increased BCL2L11 transcript levels in a dose and time dependent manner in murine and human leukemic cells, suggesting that the viability through BIM-mediated apoptosis may be targeted by both oncogenic signals. My thesis study demonstrates that Cbfbeta-SMMHC and N-RasG12D promote the survival of pre-leukemic myeloid progenitors primed for leukemia by activation of the MEK/ERK/Bim axis, and define NrasLSL-G12D; Cbfb56M mice as a valuable genetic model for the study of inv(16) AML targeted therapies. For instance, the novel CBFbeta-SMMHC inhibitor AI-10-49 shows a significant efficacy in this mouse model. This small molecule will serve as a promising first generation drug for targeted therapy of inv(16) leukemia and also a very useful tool to understand mechanisms of leukemogenesis driving by CBFbeta-SMMHC

Modularly engineering Rhodotorula toruloides for α-terpineol production

α-Terpineol is a monoterpenoid alcohol that has been widely used in the flavor, fragrance, and pharmaceutical industries because of its sensory and biological properties. However, few studies have focused on the microbial production of α-terpineol. The oleaginous yeast Rhodotorula toruloides is endowed with a natural mevalonate pathway and is a promising host in synthetic biology and biorefinery. The primary objective of this work was to engineer R. toruloides for the direct biosynthesis of α-terpineol. The improvement in monoterpenoid production was achieved through the implementation of modular engineering strategies, which included the enhancement of precursor supply, blocking of downstream pathways, and disruption of competing pathways. The results of these three methods showed varying degrees of favorable outcomes in enhancing α-terpineol production. The engineered strain 5L6HE5, with competitive pathway disruption and increased substrate supply, reached the highest product titer of 1.5 mg/L, indicating that reducing lipid accumulation is an efficient method in R. toruloides engineering for terpenoid synthesis. This study reveals the potential of R. toruloides as a host platform for the synthesis of α-terpineol as well as other monoterpenoid compounds

A small-molecule inhibitor of the aberrant transcription factor CBFβ-SMMHC delays leukemia in mice

This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on 2015 February 13; 347(6223): 779–784, DOI: 10.1126/science.aaa0314.Acute myeloid leukemia (AML) is the most common form of adult leukemia. The transcription factor fusion CBFβ-SMMHC (core binding factor β and the smooth-muscle myosin heavy chain), expressed in AML with the chromosome inversion inv(16)(p13q22), outcompetes wild-type CBFβ for binding to the transcription factor RUNX1, deregulates RUNX1 activity in hematopoiesis, and induces AML. Current inv(16) AML treatment with nonselective cytotoxic chemotherapy results in a good initial response but limited long-term survival. Here, we report the development of a protein-protein interaction inhibitor, AI-10-49, that selectively binds to CBFβ-SMMHC and disrupts its binding to RUNX1. AI-10-49 restores RUNX1 transcriptional activity, displays favorable pharmacokinetics, and delays leukemia progression in mice. Treatment of primary inv(16) AML patient blasts with AI-10-49 triggers selective cell death. These data suggest that direct inhibition of the oncogenic CBFβ-SMMHC fusion protein may be an effective therapeutic approach for inv(16) AML, and they provide support for transcription factor targeted therapy in other cancers

Risk Prediction and Assessment: Duration, Infections, and Death Toll of the COVID-19 and Its Impact on China’s Economy

This study first analyzes the national and global infection status of the Coronavirus Disease that emerged in 2019 (COVID-19). It then uses the trend comparison method to predict the inflection point and Key Point of the COVID-19 virus by comparison with the severe acute respiratory syndrome (SARS) graphs, followed by using the Autoregressive Integrated Moving Average model, Autoregressive Moving Average model, Seasonal Autoregressive Integrated Moving-Average with Exogenous Regressors, and Holt Winter’s Exponential Smoothing to predict infections, deaths, and GDP in China. Finally, it discusses and assesses the impact of these results. This study argues that even if the risks and impacts of the epidemic are significant, China’s economy will continue to maintain steady development

Numerical Investigation of Sloshing in Rectangular Tank with Permeable Baffle

Violent sloshing induced by excitation with large amplitudes or resonant frequencies may result in structural damage of the liquid-tank or even the overturning of the liquid cargo transport system. Therefore, impermeable and permeable vertical baffles were investigated numerically to suppress sloshing. The numerical simulations were based on the finite element method and arbitrary Lagrangian–Eulerian (ALE) method. The numerical model was verified by the available experimental data, numerical results and linear theoretical results. Based on the study of the effects of impermeable baffle height, amplitude and frequency of excitation on sloshing, the effects of baffle permeability on sloshing were investigated. Importantly, a critical permeability coefficient that was most effective to suppress sloshing was found. In addition, the maximum flow velocities in the tank with a baffle of small permeability coefficient were smaller than those in the tank with an impermeable baffle. While, the maximum flow velocities under a baffle of large permeability coefficient were larger than those in the tank with an impermeable baffle. Vortices were observed in the whole region of the baffle, tank bottom, tank walls and the free surface in the tank with a permeable baffle

Ionizing Radiation-Induced Cellular Senescence in Normal, Non-transformed Cells and the Involved DNA Damage Response: A Mini Review

Cellular senescence is identified by a living cell in irreversible and persistent cell cycle arrest in response to various cellular stresses. Senescent cells secrete senescence-associated secretory phenotype factors that can amplify cellular senescence and alter the microenvironments. Radiotherapy, via ionizing radiation, serves as an effective treatment for local tumor control with side effects on normal cells, which can induce inflammation and fibrosis in irradiated and nearby regions. Research has revealed that senescent phenotype is observable in irradiated organs. This process starts with DNA damage mediated by radiation, after which a G2 arrest occurs in virtually all eukaryotic cells and a mitotic bypass is possibly necessary to ultimately establish cellular senescence. Within this complex DNA damage response signaling network, ataxia telangiectasia-mutated protein, p53, and p21 stand out as the crucial mediators. Senolytic agents, a class of small molecules that can selectively kill senescent cells, hold great potential to substantially reduce the side effects caused by radiotherapy while reasonably steer clear of carcinogenesis

Research on optimal configuration strategy of energy storage capacity in grid-connected microgrid

Abstract The optimal configuration of battery energy storage system is key to the designing of a microgrid. In this paper, a optimal configuration method of energy storage in grid-connected microgrid is proposed. Firstly, the two-layer decision model to allocate the capacity of storage is established. The decision variables in outer programming model are the capacity and power of the storage system. The objective is the least investment on the battery energy storage system. The decision variable in inner programming model is the charging and discharging power of battery. The objective is the lowest power fluctuation on the connection line. Then a case containing a grid-connected microgrid with wind power, photovoltaic, battery energy storage and load is studied, and the multi-scenario probabilistic method is used. The last result of energy storage configuration is calculated through the probability of each scene

NrasG12D oncoprotein inhibits apoptosis of pre-leukemic cells expressing Cbfbeta-SMMHC via activation of MEK/ERK axis

Acute myeloid leukemia (AML) results from the activity of driver mutations that deregulate proliferation and survival of hematopoietic stem cells (HSCs). The fusion protein CBFbeta-SMMHC impairs differentiation in hematopoietic stem and progenitor cells, and induces AML in cooperation with other mutations. However, the combined function of CBFbeta-SMMHC and cooperating mutations in pre-leukemic expansion is not known. Here, we used NrasLSL-G12D; Cbfb56M knock-in mice to show that allelic expression of oncogenic NrasG12D and Cbfbeta-SMMHC increases survival of pre-leukemic short-term HSCs and myeloid progenitor cells and maintains the differentiation block induced by the fusion protein. NrasG12D and Cbfbeta-SMMHC synergize to induce leukemia in mice in a cell autonomous manner with a median latency shorter and with higher leukemia-initiating cell activity than that of mice expressing Cbfbeta-SMMHC. Furthermore, NrasLSL-G12D; Cbfb56M leukemic cells were sensitive to pharmacologic inhibition of MEK/ERK signaling pathway, increasing apoptosis and Bim protein levels. These studies demonstrate that Cbfbeta-SMMHC and NrasG12D promote the survival of pre-leukemic myeloid progenitors primed for leukemia by activation of the MEK/ERK/Bim axis, and define NrasLSL-G12D; Cbfb56M mice as a valuable genetic model for the study of inv16 AML targeted therapies

NrasG12D oncoprotein inhibits apoptosis of preleukemic cells expressing Cbfβ-SMMHC via activation of MEK/ERK axis

Acute myeloid leukemia (AML) results from the activity of driver mutations that deregulate proliferation and survival of hematopoietic stem cells (HSCs). The fusion protein CBFβ-SMMHC impairs differentiation in hematopoietic stem and progenitor cells and induces AML in cooperation with other mutations. However, the combined function of CBFβ-SMMHC and coopera

NiMn layered double hydroxide nanosheets/NiCo2O4 nanowires with surface rich high valence state metal oxide as an efficient electrocatalyst for oxygen evolution reaction

High valence transition metal oxide is significant for anode catalyst of proton membrane water electrolysis technique. Herein, we demonstrate NiMn layered double hydroxide nanosheets/NiCo 2 O 4 nanowires hierarchical nanocomposite catalyst with surface rich high valence metal oxide as an efficient catalyst for oxygen evolution reaction. A low overpotential of 310 mV is needed to drive a 10 mA cm −2 with a Tafel slope of 99 mV dec −1 , and a remarkable stability during 8 h is demonstrated in a chronoamperometry test. Theoretical calculation displays the change in the rate-determining step on the nanocomposite electrode in comparison to NiCo 2 O 4 nanowires alone. It is found high valence Ni and Mn oxide in the catalyst system can efficiently facilitate the charge transport across the electrode/electrolyte interface. The enhanced electrical conductivity, more accessible active sites and synergistic effects between NiMn layered double hydroxide nanosheets and NiCo 2 O 4 nanowires can account for the excellent oxygen evolution reaction. The catalytic performance is comparable to most of the best non-noble catalysts and IrO 2 noble catalyst, indicating the promising applications in water-splitting technology. It is an important step in the development of hierarchical nanocomposites by surface valence state tuning as an alternative to noble metals for oxygen evolution reaction