Biochemistry And Microbial Sciences - Research Publications

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Author: search.filters.author.Gupta, SanjaySubject: search.filters.subject.drug resistance

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    Withaferin A mediated changes of miRNA expression in breast cancer-derived mammospheres
    (John Wiley and Sons Inc, 2022-06-30T00:00:00) Prajapati, Kumari Sunita; Shuaib, Mohd.; Gupta, Sanjay; Kumar, Shashank
    Breast cancer is a heterogeneous disease consisting of atypical cell populations that share stem cell-like characteristics associated with therapeutic resistance, disease relapse, and poor clinical outcome. MicroRNAs (miRNA),�and small noncoding RNA, are pivotal in the regulation of self-renewal, stemness, and cellular differentiation. Withaferin A (WA), a steroidal lactone, is a major bioactive constituent of Withania somnifera (Solanaceae) known for its anticancer properties. In this study, the effect of WA on modulation of miRNA expression in breast cancer-derived mammosphere was assessed utilizing small RNA sequencing. Treatment with WA inhibited MCF-7 and T47D cells derived mammosphere formation with a significant decrease in CD44, EpCAM, Nanog, OCT4, and SOX2 as markers of self-renewal and stemness. Small RNA sequencing demonstrated a total of 395 differentially expressed miRNAs (DEMs) including 194 upregulated and 201 downregulated miRNAs in WA-treated�MCF-7 mammospheres. Bioinformatics analysis utilizing the�KEGG pathway, Gene Ontology enrichment, protein?protein, and miRNA-mRNA interaction network identified altered expression in a few hub genes viz.�AKT1, PTEN, MYC, CCND1,�VEGFA,�NOTCH1, and�IGFR1�associated with DEMs in WA-treated�mammospheres. Further quantitative�RT-PCR analysis validated the expression of DEMs including miR-549a-5p, miR-1247-5p, miR-124-5p, miR-137-5p, miR-34a-5p, miR-146a-5p, miR-99a-5p, miR-181a-5p, let-7c-5p, and let-7a-5p. In particular, let-7c-5p is designated as a tumor suppressor in breast cancer. An increase in miR-let-7c-5p expression was noted after WA treatment, with a simultaneous decrease in CCND1 and c-MYC at mRNA and protein levels. Taken together, our study demonstrated WA-mediated miRNA expression, in particular, upregulation of miR-let-7c-5p, leads to the inhibition of breast cancer cells derived mammospheres. � 2022 Wiley Periodicals LLC.
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    Drug Resistance Mechanism of M46I-Mutation-Induced Saquinavir Resistance in HIV-1 Protease Using Molecular Dynamics Simulation and Binding Energy Calculation
    (MDPI, 2022-03-30T00:00:00) Rana, Nilottam; Singh, Atul Kumar; Shuaib, Mohd; Gupta, Sanjay; Habiballah, Mahmoud M.; Alkhanani, Mustfa F.; Haque, Shafiul; Reshi, Mohd Salim; Kumar, Shashank
    Drug-resistance-associated mutation in essential proteins of the viral life cycle is a major concern in anti-retroviral therapy. M46I, a non-active site mutation in HIV-1 protease has been clinically associated with saquinavir resistance in HIV patients. A 100 ns molecular dynamics (MD) simulation and MM-PBSA calculations were performed to study the molecular mechanism of M46I-mutation-based saquinavir resistance. In order to acquire deeper insight into the drug-resistance mechanism, the flap curling, closed/semi-open/open conformations, and active site compactness were studied. The M46I mutation significantly affects the energetics and conformational stability of HIV-1 protease in terms of RMSD, RMSF, Rg, SASA, and hydrogen formation potential. This mutation significantly decreased van der Waals interaction and binding free energy (?G) in the M46I�saquinavir complex and induced inward flap curling and a wider opening of the flaps for most of the MD simulation period. The predominant open conformation was reduced, but inward flap curling/active site compactness was increased in the presence of saquinavir in M46I HIV-1 protease. In conclusion, the M46I mutation induced structural dynamics changes that weaken the protease grip on saquinavir without distorting the active site of the protein. The produced information may be utilized for the discovery of inhibitor(s) against drug-resistant HIV-1 protease. � 2022 by the authors. Licensee MDPI, Basel, Switzerland.