Browsing by Author "Kumar, Santosh"

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Design, synthesis and anticancer activity of 2-arylimidazo[1,2-a]pyridinyl-3-amines
(Academic Press Inc., 2021-11-01T00:00:00) Yadav, Umesh Prasad; Ansari, Arshad J.; Arora, Sahil; Joshi, Gaurav; Singh, Tashvinder; Kaur, Harsimrat; Dogra, Nilambra; Kumar, Raj; Kumar, Santosh; Sawant, Devesh M.; Singh, Sandeep
A series of imido-heterocycle compounds were designed, synthesized, characterized, and evaluated for the anticancer potential using breast (MCF-7 and MDA-MB-231), pancreatic (PANC-1), and colon (HCT-116 and HT-29) cancer cell lines and normal cells, while normal cells showed no toxicity. Among the screened compounds, 4h exhibited the best anticancer potential with IC50 values ranging from 1 to 5.5 ?M. Compound 4h caused G2/M phase arrest and apoptosis in all the cell lines except MDA-MB-231 mammosphere formation was inhibited. In-vitro enzyme assay showed selective topoisomerase II? inhibition by compound 4h, leading to DNA damage as observed by fluorescent staining. Cell signalling studies showed decreased expression of cell cycle promoting related proteins while apoptotic proteins were upregulated. Interestingly MDA-MB-231 cells showed only cytostatic effects upon treatment with compound 4h due to defective p53 status. Toxicity study using overexpression of dominant-negative mutant p53 in MCF-7 cells (which have wild type functional p53) showed that anticancer potential of compound 4h is positively correlated with p53 expression. � 2021 Elsevier Inc.
Immunodominant conserved moieties on spike protein of SARS-CoV-2 renders virulence factor for the design of epitope-based peptide vaccines
(Springer, 2023-11-23T00:00:00) Mohapatra, Subhashree; Kumar, Santosh; Kumar, Shashank; Singh, Atul Kumar; Nayak, Bismita
The outbreak of novel SARS-CoV-2 virion has wreaked havoc with a high prevalence of respiratory illness and high transmission due to a vague understanding of the viral antigenicity, augmenting the dire challenge to public health globally. This viral member necessitates the expansion of diagnostic and therapeutic tools to track its transmission and confront it through vaccine development. Therefore, prophylactic strategies are mandatory. Virulent spike proteins can be the most desirable candidate for the computational design of vaccines targeting SARS-CoV-2, followed by the meteoric development of immune epitopes. Spike protein was characterized using existing bioinformatics tools with a unique roadmap related to the immunological profile of SARS-CoV-2 to predict immunogenic virulence epitopes based on antigenicity, allergenicity, toxicity, immunogenicity, and population coverage. Applying in silico approaches, a set of twenty-four B lymphocyte-based epitopes and forty-six T lymphocyte-based epitopes were selected. The predicted epitopes were evaluated for their intrinsic properties. The physico-chemical characterization of epitopes qualifies them for further in vitro and in vivo analysis and pre-requisite vaccine development. This study presents a set of screened epitopes that bind to HLA-specific allelic proteins and can be employed for designing a peptide vaccine construct against SARS-CoV-2 that will confer vaccine-induced protective immunity due to its structural stability. � 2023, The Author(s), under exclusive licence to Indian Virological Society.
Let-7a induces metabolic reprogramming in breast cancer cells via targeting mitochondrial encoded ND4
(BioMed Central Ltd, 2021-11-27T00:00:00) Sharma, Praveen; Sharma, Vibhuti; Ahluwalia, Tarunveer Singh; Dogra, Nilambra; Kumar, Santosh; Singh, Sandeep
Background and objectives: MicroRNA (miRNA) that translocate from the nucleus to mitochondria are referred to as mitochondrial microRNA (mitomiR). Albeit mitomiRs have been shown to modulate gene expression, their functional impact within mitochondria is unknown. The main objective of this study is to investigate whether the mitochondrial genome is regulated by miR present inside the mitochondria. Methods and results: Here, we report mitomiR let-7a regulates mitochondrial transcription in breast cancer cells and reprogram the metabolism accordingly. These effects were mediated through the interaction of let-7a with mtDNA, as studied by RNA pull-down assays, altering the activity of Complex I in a cell line-specific manner. Our study, for the first time, identifies the role of mitomiR (let-7a) in regulating the mitochondrial genome by transcriptional repression and its contribution to regulating mitochondrial metabolism of breast cancer cells. Conclusion: These findings uncover a novel mechanism by which mitomiR regulates mitochondrial transcription. � 2021, The Author(s).
Natural Compound-Based Nanoparticles to Target Free Radicals in Cancer
(Springer Singapore, 2022-09-28T00:00:00) Yadav, Umesh Prasad; Rhuthuparna, M.; Vasudeva, Kanika; Suman, Prabhat; Munshi, Anjana; Kumar, Santosh; Singh, Sandeep
Cell proliferation and malignant transformation are enabled by genetic and epigenetic changes. During the malignancy process, malignant cells acquire distinguishing characteristics. Cancer cells have acquired the ability to generate more reactive oxygen species (ROS), resulting in high oxidative stress. ROS-mediated signaling is needed for cancer cell physiology, and high levels of ROS cause oxidative stress-induced cytotoxicity in cancer cells. To avoid ROS-mediated cytotoxicity, cancer cells modulate their redox state through various antioxidant mechanisms and keep their ROS levels below the threshold. Cancer treatment that targets oxidative stress is an appealing option. Many natural oxidative stress modulators and bioactive compounds have been used in the treatment of cancer. Conventional uptake of bioactive molecule is associated with lower bioavailability, solubility, unlikely biodistribution, and side effects. Traditional drug uptake is improved by nanoformulation, making it easier to overcome side effects, improve biodistribution, and extend drug duration time. Natural prooxidant-loaded nanoparticles efficiently carry prooxidant to the tumor site and selectively and efficiently induce oxidative stress-mediated cell death in cancer cells. � Springer Nature Singapore Pte Ltd. 2022.