scholarly journals The application of tetracyclineregulated gene expression systems in the validation of novel drug targets in Mycobacterium tuberculosis

2015 ◽  
Vol 6 ◽  
Author(s):  
Joanna C. Evans ◽  
Valerie Mizrahi
2014 ◽  
Author(s):  
N. Susantha Chandrasekera ◽  
Mai A Bailey ◽  
Megan Files ◽  
Torey Alling ◽  
Stephanie K Florio ◽  
...  

We demonstrated that the 3-substituted benzothiophene-1,1-dioxide class of compounds are effective inhibitors of Mycobacterium tuberculosis growth under aerobic conditions. We examined substitution at the C-3 position of the benzothiophene-1,1-dioxide series systematically to delineate structure-activity relationships influencing potency and cytotoxicity. Compounds were tested for inhibitory activity against virulent M. tuberculosis and eukaryotic cells. The tetrazole substituent was most potent, with a minimum inhibitory concentration (MIC) of 2.6 µM. However, cytotoxicity was noted with even more potency (Vero cell TC50 = 0.1 µM). Oxadiazoles had good anti-tubercular activity (MICs of 3–8 µM), but imidazoles, thiadiazoles and thiazoles had little activity. Cytotoxicity did not track with anti-tubercular activity, suggesting different targets or mode of action between bacterial and eukaryotic cells. However, we were unable to derive analogs without cytotoxicity; all compounds synthesized were cytotoxic (TC50 of 0.1–5 µM). We conclude that cytotoxicity is a liability in this series precluding it from further development. However, the series has potent anti-tubercular activity and future efforts towards identifying the mode of action could result in the identification of novel drug targets.


2014 ◽  
Author(s):  
N. Susantha Chandrasekera ◽  
Mai A Bailey ◽  
Megan Files ◽  
Torey Alling ◽  
Stephanie K Florio ◽  
...  

We demonstrated that the 3-substituted benzothiophene-1,1-dioxide class of compounds are effective inhibitors of Mycobacterium tuberculosis growth under aerobic conditions. We examined substitution at the C-3 position of the benzothiophene-1,1-dioxide series systematically to delineate structure-activity relationships influencing potency and cytotoxicity. Compounds were tested for inhibitory activity against virulent M. tuberculosis and eukaryotic cells. The tetrazole substituent was most potent, with a minimum inhibitory concentration (MIC) of 2.6 µM. However, cytotoxicity was noted with even more potency (Vero cell TC50 = 0.1 µM). Oxadiazoles had good anti-tubercular activity (MICs of 3–8 µM), but imidazoles, thiadiazoles and thiazoles had little activity. Cytotoxicity did not track with anti-tubercular activity, suggesting different targets or mode of action between bacterial and eukaryotic cells. However, we were unable to derive analogs without cytotoxicity; all compounds synthesized were cytotoxic (TC50 of 0.1–5 µM). We conclude that cytotoxicity is a liability in this series precluding it from further development. However, the series has potent anti-tubercular activity and future efforts towards identifying the mode of action could result in the identification of novel drug targets.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5318-5318
Author(s):  
Jason H. Rogers ◽  
Kristin S. Owens ◽  
Jake M. Vargas ◽  
Cheryl L. Willman ◽  
Robert Hromas ◽  
...  

Abstract B-precursor acute lymphoblastic leukemia (ALL) is the most common cancer of childhood. While it represents a highly curable malignancy, a significant number of children still relapse or present with disease that is resistant to therapeutic intensification. With the increasing intensity of curative treatment, there is also an increased incidence of late effects that adversely affect the quality of life of survivors. Previously, a large scale microarray gene expression analysis was undertaken in order to identify genes predictive of outcome that could enhance risk classification, thereby identifying children who might be cured with less intensive therapy or those who fail current regimens and require novel therapies for cure. From analysis of 254 pediatric ALL samples registered to various COG clinical trials, gene expression classifiers were identified that are highly predictive of poor and favorable outcome in precursor B-cell ALL. The goal of this project is to study the biologic function and role in hematopoiesis and leukemogenesis of the genes predictive of outcome and to determine whether any of these genes may serve as novel drug targets. To this end, we have developed a system to examine the effect of these genes on the cancer-promoting activity of the v-Abl oncogene. We have established pre-B cell lines by infecting primary mouse bone marrow cells with a virus expressing v-Abl. These lines were then engineered to express two of the genes we identified that were associated with poor or good treatment outcomes, RANTES (CCL5) and OPAL1 respectively. Consistent with the association of RANTES expression with poor outcome, v-Abl/RANTES pre-B cells are more proliferative than v-Abl cells, and form larger colonies in methylcellulose cultures without added cytokines. OPAL1 had the opposite effect on pre-B cell growth. V-Abl pre-B cells expressing OPAL1 were less proliferative and generated fewer colonies in methylcellulose cultures. To determine whether RANTES made the v-Abl pre-B cells more leukemic, we transplanted v-Abl or v-Abl/RANTES pre-B cells into syngeneic mice. Mice were noticeably ill 30 days post-transplant. Mice injected with v-Abl/RANTES cells had enlarged lymph nodes and increased numbers of white cells in their peripheral blood. The percentage of pre-B cells in the bone marrow, lymph nodes and spleen was higher in v-Abl/RANTES transplanted mice compared to v-Abl transplanted mice. Currently our data demonstrates that the outcome genes are playing a mechanistic role in the susceptibility of leukemic cells to therapy, and are not merely epiphenomenon. This suggests that the products of these genes and their associated pathways may be novel drug targets. Such targeted therapy has the potential of being less toxic than current nonspecific treatment regimens.


2017 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohana Rao Anguru ◽  
Ashok Kumar Taduri ◽  
Rama Devi Bhoomireddy ◽  
Malathi Jojula ◽  
Shravan Kumar Gunda

2018 ◽  
Vol 2 (1) ◽  
pp. 14-21
Author(s):  
Safaa Kishk ◽  
Mohamed A. Helal ◽  
Mohamed S. Gomaa ◽  
Ismail Salama ◽  
Samia Moustafa ◽  
...  

2020 ◽  
Vol 17 (11) ◽  
pp. 1422-1431
Author(s):  
Shradheya R.R. Gupta ◽  
Ekta Gupta ◽  
Avnam Ohri ◽  
Sandeep Kumar Shrivastava ◽  
Sumita Kachhwaha ◽  
...  

Background: Mycobacterium tuberculosis is a causative agent of tuberculosis. It is a non-motile, acid-fast, obligatory aerobic bacterium. Finding novel drug targets in Mycobacterium tuberculosis has become extremely important as the bacterium is evolving into a more dangerous multi-drug resistant pathogen. The predominant strains in India belong to the Central-Asian, East- African Indian, and Beijing clad. For the same reason, the whole proteomes of a non-virulent strain (H37Ra), a virulent (H37Rv) and two clinical strains, a Central-Asian clad (CAS/NITR204) and a Beijing clad (CCDC5180) have been selected for comparative study. Selecting a phylogenetically close and majorly studied non-virulent strain is helpful in removing the common and undesired proteins from the study. Objective: The study compares the whole proteome of non-virulent strain with the other three virulent strains to find a unique protein responsible for virulence in virulent strains. It is expected that the drugs developed against identified targets will be specific to the virulent strains. Additionally, to assure minimal toxicity to the host, we also screened the human proteome. Methods: Comparative proteome analysis was used for target identification and in silico validation of identified target protein Rv2466c, identification of the respective ligand of the identified target protein and binding interaction study using Molecular docking and Molecular Dynamic Simulation study were used in this study. Results and Discussion: Finally, eleven proteins were found to be unique in virulent strain only and out of which, Rv2466c (PDB-ID: 4ZIL) was found to be an essential protein and identified as a putative drug target protein for further study. The compound glutathione was found to be a suitable inhibitor for Rv2466c. In this study, we used a comparative proteomics approach to identify novel target proteins. Conclusion: This study is unique as we are assured that the study will move forward the research in a new direction to cure the deadly disease (tuberculosis) caused by Mycobacterium tuberculosis. Rv2466c was identified as a novel drug target and glutathione as a respective ligand of Rv2466c. Discovery of the novel drug target as well as the drug will provide a solution to drug resistance as well as the infection caused by Mycobacterium tuberculosis.


2020 ◽  
Vol 19 (5) ◽  
pp. 300-300 ◽  
Author(s):  
Sorin Avram ◽  
Liliana Halip ◽  
Ramona Curpan ◽  
Tudor I. Oprea

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