87 research outputs found
Structure, activity, and inhibition of the carboxyltransferase beta-Subunit of acetyl coenzyme a carboxylase (AccD6) from mycobacterium tuberculosis
No full textIn Mycobacterium tuberculosis, the carboxylation of acetyl coenzyme A (acetyl-CoA) to produce malonyl-CoA, a building block in long-chain fatty acid biosynthesis, is catalyzed by two enzymes working sequentially: a biotin carboxylase (AccA) and a carboxyltransferase (AccD). While the exact roles of the three different biotin carboxylases (AccA1 to -3) and the six carboxyltransferases (AccD1 to -6) in M. tuberculosis are still not clear, AccD6 in complex with AccA3 can synthesize malonyl-CoA from acetyl-CoA. A series of 10 herbicides that target plant acetyl-CoA carboxylases (ACC) were tested for inhibition of AccD6 and for whole-cell activity against M. tuberculosis. From the tested herbicides, haloxyfop, an arylophenoxypropionate, showed in vitro inhibition of M. tuberculosis AccD6, with a 50% inhibitory concentration (IC50) of 21.4 ± 1 μM. Here, we report the crystal structures of M. tuberculosis AccD6 in the apo form (3.0 Å) and in complex with haloxyfop-R (2.3 Å). The structure of M. tuberculosis AccD6 in complex with haloxyfop-R shows two molecules of the inhibitor bound on each AccD6 subunit. These results indicate the potential for developing novel therapeutics for tuberculosis based on herbicides with low human toxicity.Manchi C. M. Reddy, Ardala Breda, John B. Bruning,* Mukul Sherekar, Spandana Valluru, Cory Thurman, Hannah Ehrenfeld,
James C. Sacchettin
Protective effects of miR-24-2-5p in early stages of breast cancer bone metastasis
No full textBackground: Bone is the most frequent site of metastasis for breast cancer (BC). Metastatic BC cells interact with bone cells, including osteoclasts and osteoblasts, creating a cancer niche where they seed and proliferate. MicroRNAs (miRNAs) are regulators of breast-to-bone metastasis progression. MiR-24-2-5p has previously been shown to have roles in both breast cancer progression and inhibition of osteogenic differentiation. However, a direct link between miR-24-2-5p activity and the onset of bone metastasis remains ill-defined. Methods: Analysis of the expression of miR-24 forms (miR-24-2-5p, miR-24-3p, miR-24-1-5p) in the serum from early-stage BC patients at baseline (time of surgery) was conducted. MiR-24-2-5p overexpression in BC cells (NW1, a luc2-positive subpopulation of MDA-MB-231, and MCF7) was obtained by miRNA mimic transfection or lentivirus transduction. MiR-24-2-5p downregulation in BC cells (ZR-75-1, T-47D, SK-BR-3) was obtained by miRNA inhibitor transfection. Cell proliferation, migration and/or invasion assays were performed to assess BC cell functions after modulation of miR-24-2-5p expression. An animal model was used to assess the effect of miR-24-2-5p overexpression on early BC metastasis formation, as judged by bioluminescence imaging, and on bone remodelling, following measurement of circulating bone resorption (CTX-I) and bone formation (P1NP) markers. The effect of conditioned medium from miR-24-2-5p-overexpressing BC cells on human and murine osteoclast differentiation was investigated. Endogenous miR-24-2-5p expression levels were also quantified during murine osteoclast differentiation. RNA-sequencing (RNA-seq) analysis of BC cells was performed to evaluate transcriptomic changes associated with miR-24-2-5p overexpression. Selected modulated transcripts upon miR-24-2-5p overexpression were further validated by real-time qPCR. Results: Low expression levels of miR-24-2-5p, but not other miR-24 forms (miR-24-3p, miR-24-1-5p), in the serum from early-stage BC patients were associated with a high risk to develop future (bone) metastases. MiR-24-2-5p was also present in small extracellular vesicles secreted from BC cells. Forced expression of miR-24-2-5p in BC cells (NW1, MCF7) reduced their malignant traits (migration, invasion, and proliferation) in vitro. Furthermore, miR-24-2-5p overexpression in NW1 cells reduced metastasis, particularly in bone, and decreased bone turnover in vivo. RNA-seq and real-time qPCR analyses of NW1 and MCF7 cells overexpressing miR-24-2-5p showed the downregulation of common transcripts (CNNM4, DCTD, FMR1, PIGS, HLA-A, ICK, SH3BGRL2, WDFY, TRAF9B, IL6ST, PEX10, TRIM59). The conditioned medium from BC cells overexpressing miR-24-2-5p decreased human and murine osteoclast differentiation in vitro. Additionally, endogenous miR-24-2-5p expression levels in murine bone marrow-derived monocytes decreased during their differentiation into osteoclasts, further suggesting an inhibitory role for miR-24-2-5p during osteoclastogenesis. Conclusion: MiR-24-2-5p exerts multiple protective roles in the early steps of BC bone metastasis by reducing malignant BC cell traits and tumour cell dissemination in bone, as well as by reducing the differentiation of precursors into mature osteoclasts
MiR-662 is associated with metastatic relapse in early-stage breast cancer and promotes metastasis by stimulating cancer cell stemness
No full textBackgroundBreast cancer (BC) metastasis, which often occurs in bone, contributes substantially to mortality. MicroRNAs play a fundamental role in BC metastasis, although microRNA-regulated mechanisms driving metastasis progression remain poorly understood.MethodsMiRome analysis in serum from BC patients was performed by TaqMan & TRADE; low-density array. MiR-662 was overexpressed following MIMIC-transfection or lentivirus transduction. Animal models were used to investigate the role of miR-662 in BC (bone) metastasis. The effect of miR-662-overexpressing BC cell conditioned medium on osteoclastogenesis was investigated. ALDEFLUOR assays were performed to study BC stemness. RNA-sequencing transcriptomic analysis of miR-662-overexpressing BC cells was performed to evaluate gene expression changes.ResultsHigh levels of hsa-miR-662 (miR-662) in serum from BC patients, at baseline (time of surgery), were associated with future recurrence in bone. At an early-stage of the metastatic disease, miR-662 could mask the presence of BC metastases in bone by inhibiting the differentiation of bone-resorbing osteoclasts. Nonetheless, metastatic miR-662-overexpressing BC cells then progressed as overt osteolytic metastases thanks to increased stem cell-like traits.ConclusionsMiR-662 is involved in BC metastasis progression, suggesting it may be used as a prognostic marker to identify BC patients at high risk of metastasis
FOCUS Spring/Summer 2003
No full textContents: Anti-corporate Farming Laws and Industry Structure: The Case of Initiative 300 and Cattle Feeding by Azzeddine M. Azzam, John R. Schroeter, and J. David Aiken Grandfathered Corporations and Initiative 300 by J. David Aiken New Generation Cooperatives Are Part of UNL’s Educational Effort by Lynn H. Lutgen Switchgrass—A Biomass Energy Crop for the Great Plains? by Richard K. Perrin, Kenneth P. Vogel, and Marty R. Schmer Market Journal Presents Analysis of Agricultural Markets and Risk Management Strategies by H. Douglas Jose Off-farm Employment and Income in Nebraska by Ram Valluru, H. Douglas Jose, and Dennis M. Conley MBA in Agribusiness by Dennis M. Conley Focus on research Focus on outreach Focus on teaching Focus on peopl
FOCUS Spring/Summer 2003
No full textContents: Anti-corporate Farming Laws and Industry Structure: The Case of Initiative 300 and Cattle Feeding by Azzeddine M. Azzam, John R. Schroeter, and J. David Aiken Grandfathered Corporations and Initiative 300 by J. David Aiken New Generation Cooperatives Are Part of UNL’s Educational Effort by Lynn H. Lutgen Switchgrass—A Biomass Energy Crop for the Great Plains? by Richard K. Perrin, Kenneth P. Vogel, and Marty R. Schmer Market Journal Presents Analysis of Agricultural Markets and Risk Management Strategies by H. Douglas Jose Off-farm Employment and Income in Nebraska by Ram Valluru, H. Douglas Jose, and Dennis M. Conley MBA in Agribusiness by Dennis M. Conley Focus on research Focus on outreach Focus on teaching Focus on peopl
Calcium channel signalling and modulation in colorectal cancer
No full textBackground
Colorectal cancer (CRC) is a huge global problem, being the 3rd most common cancer worldwide. It is caused by an interplay between genetic and chromosomal aberrations as well as dietary and lifestyle factors. Calcium channel receptor signalling is important in a number of cancers, in particular calcium releaseactivated calcium (CRAC) channel signalling and more recently PIEZO1. The hypothesis is that modulating these channels will have physiological effects on cancer growth in CRC.
Key Results
A novel ORAI1 inhibitor, named JPIII, demonstrated better pharmacokinetic properties than existing CRAC channel inhibitors, and inhibited ORAI1 channel function in both CRC and human umbilical vein endothelial cells (HUVECs). Furthermore, JPIII suppressed cell viability, migration and invasion in both CRC and endothelial cells. ORAI1 channel inhibition inhibited cell viability without causing cell death in HUVECs. JPIII reduced cell viability and clonogenicity of CRCs. Furthermore, JPIII treatment activated autophagy whilst simultaneously inhibiting AKT phosphorylation. In addition, a role for PIEZO1 in CRC tumourigenesis is described for the first time. PIEZO1 channels are functionally expressed, and PIEZO1 siRNA knockdown inhibited CRC viability and resulted in an increase in G2/M cell cycle arrest. The Cancer Genome Atlas (TCGA) transcriptome data revealed that ORAI1 and PIEZO1 are differentially overexpressed in CRC relative to normal colon.
However, calcium signalling and ion transport processes on the whole are downregulated in CRC. ORAI1 and PIEZO1 expression does not vary across disease stage or survival outcomes. However, expression of both channels was inversely associated with lymphatic invasion. Both ORAI1 and PIEZO1 expression demonstrated a tumour-specific correlation with one another that was not present in normal colon, and expression associated with IGF2R, postulating a potential oncogenic process for further research.
Conclusion
This work has demonstrated that both ORAI1 and PIEZO1 are involved in CRC molecular signalling
Development of robust extended Kalman filter and moving window estimator for simultaneous state and parameter/disturbance estimation
No full textSimultaneous occurrence of gross errors (outliers/biases/drifts) in the measured signals, and drifting disturbances/parameter variations affecting the system dynamics can lead to biased state estimates, and, in turn, can lead to deterioration in the performance of model-based monitoring and control schemes. In this work, robust recursive and moving window based Bayesian state and parameter estimators are developed that are robust w.r.t. gross errors in the measurements and can simultaneously estimate non-additive unmeasured disturbance/parameter variations. Using Bayes' rule, the update step of Kalman filter (KF) is recast as an optimization problem. The optimization is then modified by replacing the likelihood term in the objective function with cost function defined by an M-estimator. The M-estimators considered in this work are Huber's Fair function and Hampel's redescending estimator. The reformulated KF is then used as a basis for reformulating extended Kalman filter (EKF). This re-formulated EKF is then used for developing robust simultaneous state and parameter estimation schemes. In particular, a robust version of recently proposed moving window based state and parameter estimator [1] has been developed. The resulting formulation can be viewed as a hybrid approach, in which the gross errors in the measurements are dealt with in a passive manner, with an active elimination of model plant mismatch by estimating unmeasured disturbance/parameter variations simultaneously. The efficacy of the proposed robust state and parameter estimators is demonstrated by conducting simulation studies and experimental studies. Analysis of the simulation and experimental results reveal that the proposed robust recursive and moving window based state and parameter estimators significantly reduce or completely nullify the effect of gross errors on the state estimates while simultaneously estimating drifting unmeasured disturbances/parameters. The simulation study also underscores the importance of simultaneous estimation of unmeasured disturbances/parameters while achieving robustness using the M-estimators. Moreover, Hampel's redescending estimator is found to be a better choice of M-estimator than the popular Huber's Fair function, as the redescending estimator can completely nullify the effect of gross errors on the state and parameter estimates. (C) 2018 Elsevier Ltd. All rights reserved
MicroRNAs and their roles in breast cancer bone metastasis
No full textBone metastasis occurs in advanced stages of breast cancer, worsening the quality of life and increasing the mortality of patients. Current treatments for bone metastasis are only palliative, and efficient therapeutic targets need to be still identified. MicroRNAs (miRNAs) are a large class of small non-coding RNAs that regulate gene expression within cells. Interestingly, the expression of certain miRNAs has been associated with several stages of bone metastasis progression, highlighting the importance of these small RNAs during the course of the metastatic disease. In this review, we aim to summarise the most recent findings on miRNAs and their mRNA targets in driving breast cancer bone metastasis. Furthermore, we discuss the possibility to use miRNAs as direct therapeutic targets or as advanced therapies for breast cancer bone metastasis, as well as their potential as predictive biomarkers of bone metastasis for an early diagnosis and a better tailoring of therapies for cancer patients
Ultrasound Molecular Imaging With BR55 in Patients With Breast and Ovarian Lesions: First-in-Human Results
No full textPurpose We performed a first-in-human clinical trial on ultrasound molecular imaging (USMI) in patients with breast and ovarian lesions using a clinical-grade contrast agent (kinase insert domain receptor [KDR] -Targeted contrast microbubble [MBKDR]) that is targeted at the KDR, one of the key regulators of neoangiogenesis in cancer. The aim of this study was to assess whether USMI using MBKDR is safe and allows assessment of KDR expression using immunohistochemistry (IHC) as the gold standard. Methods Twenty-four women (age 48 to 79 years) with focal ovarian lesions and 21 women (age 34 to 66 years) with focal breast lesions were injected intravenously with MB KDR (0.03 to 0.08 mL/kg of body weight), and USMI of the lesions was performed starting 5 minutes after injection up to 29 minutes. Blood pressure, ECG, oxygen levels, heart rate, CBC, and metabolic panel were obtained before and after MBKDR administration. Persistent focal MBKDR binding on USMI was assessed. Patients underwent surgical resection of the target lesions, and tissues were stained for CD31 and KDR by IHC. Results USMI withMBKDR was well tolerated by all patients without safety concerns. Among the 40 patients included in the analysis, KDR expression on IHC matched well with imaging signal on USMI in 93% of breast and 85% of ovarian malignant lesions. Strong KDR-Targeted USMI signal was present in 77% of malignant ovarian lesions, with no targeted signal seen in 78% of benign ovarian lesions. Similarly, strong targeted signal was seen in 93% of malignant breast lesions with no targeted signal present in 67% of benign breast lesions. Conclusion USMI with MBKDR is clinically feasible and safe, and KDR-Targeted USMI signal matches well with KDR expression on IHC. This study lays the foundation for a new field of clinical USMI in cancer
Genetic and molecular bases of yield-associated traits: a translational biology approach between rice and wheat
No full textInternational audienceTransferring the knowledge bases between related species may assist in enlarging the yield potential of crop plants. Being cereals, rice and wheat share a high level of gene conservation; however, they differ at metabolic levels as a part of the environmental adaptation resulting in different yield capacities. This review focuses on the current understanding of genetic and molecular regulation of yield-associated traits in both crop species, highlights the similarities and differences and presents the putative knowledge gaps. We focus on the traits associated with phenology, photosynthesis, and assimilate partitioning and lodging resistance; the most important drivers of yield potential. Currently, there are large knowledge gaps in the genetic and molecular control of such major biological processes that can be filled in a translational biology approach in transferring genomics and genetics informations between rice and wheat
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