bioRxiv Science⌕ Search

Biology subjects

Saha, M. K.

Publications and source records attributed to Saha, M. K..

2 recordsLinked to original sources

Small Molecule Inhibitors Targeting Methyltransferase-Like (METTL) Proteins Against Hepatocellular Carcinoma: A Comprehensive DrugRepurposing Approach

An efficient and durable multi-targeted therapeutic drug against hepatocellular carcinoma (HCC) has recently been a growing concern for tackling the chemoresistance of approved anti-HCC drugs. Recent studies indicated that methyltransferase-like (METTL) proteins including METTL1, METTL3, METTL6, METTL16, and METTL18, have overexpressed and associated with the progression of HCC malignancy, and making them excellent biomarkers. Here, we present a series of bioinformatics study including novel compound repurposing approach, molecular docking, pharmacophore modeling, and molecular dynamic simulation, which revealed two first-in-class highly potent catalytic multi-target inhibitors (ZINC70666503 and ZINC13000658 with 87% and 82% drug scores, respectively) of methyltransferase-like proteins. Comparatively, these two inhibitors showed a notable binding affinity against studied METTL proteins. Furthermore, ADME and toxicity analysis suggested that these two commercially available compounds have good drug-likeliness properties with no potent toxic effects. Of note, the molecular dynamics study supported their conformational stability and high selectivity at the pocket of proteins adenosine moiety of S-Adenosyl Methionine. However, this comprehensive analysis needs in vivo validation to facilitate multi-targeting therapeutic development against hepatocellular carcinoma.

cancer biology↗

A vitamin D-RelB/NF-κB pathway limits Chandipura virus multiplication by rewiring the homeostatic state of autoregulatory type 1 interferon-IRF7 signaling

Besides its functions in the skeletomuscular system, vitamin D also promotes protective immunity against viral pathogens. Viral sensing by mammalian cells triggers nuclear activation of RelA/NF-{kappa}B and IRF3 factors, which collaborate in mediating the early induction of antiviral type 1 interferons (T1-IFNs). Autocrine T1-IFN signaling further accumulates otherwise negligibly expressed IRF7 in virus-infected cells that then sustains T1-IFN production in a positive feedback. Surprisingly, prior cell-culture studies revealed that vitamin D actually suppresses signal-induced RelA activation. Indeed, it remains unclear how vitamin D limits viral multiplication in a cell-autonomous manner. Here, we examined the role of vitamin D in controlling cellular infections by the Chandipura virus (CHPV), a cytoplasmic RNA virus implicated in human epidemics. We found that vitamin D conditioning produced an altered cell state less permissive for CHPV multiplication because of the heightened expression of T1-IFNs. It is thought that viruses also induce a distinct RelB/NF-{kappa}B activity, which counteracts RelA-driven T1-IFN expressions in infected cells. Our analyses instead characterized a basal nuclear RelB activity, which was downregulated upon vitamin D-mediated suppression of RelB synthesis. Interestingly, this vitamin D-RelB pathway provoked IRF7-mediated positive autoregulation augmenting constitutive T1-IFN expressions even in the absence of viral infections. Accordingly, RelB deficiency rendered redundant, while IRF7 depletion abrogated antiviral vitamin D actions. In sum, our study suggests that the homeostatic state of the signaling circuitry comprising of the NF-{kappa}B and T1-IFN pathways connects micronutrients to antiviral immunity at the cellular level. Significance statementVitamin D limits viral infections, but the underlying mechanism remains unclear. Linking micronutrients to antiviral immunity, Ratra et al. characterize an immune signaling circuitry engaged by vitamin D that generates a cellular state less permissive to infections by Chandipura virus, a pathogen of public health importance.

immunology↗