title: Chelerythrine down regulates expression of VEGFA, BCL2 and KRAS by arresting G-Quadruplex structures at their promoter regions.
abstract: A putative anticancer plant alkaloid, Chelerythrine binds to G-quadruplexes at promoters of VEGFA, BCL2 and KRAS genes and down regulates their expression. The association of Chelerythrine to G-quadruplex at the promoters of these oncogenes were monitored using UV absorption spectroscopy, fluorescence anisotropy, circular dichroism spectroscopy, CD melting, isothermal titration calorimetry, molecular dynamics simulation and quantitative RT-PCR technique. The pronounced hypochromism accompanied by red shifts in UV absorption spectroscopy in conjunction with ethidium bromide displacement assay indicates end stacking mode of interaction of Chelerythrine with the corresponding G-quadruplex structures. An increase in fluorescence anisotropy and CD melting temperature of Chelerythrine-quadruplex complex revealed the formation of stable Chelerythrine-quadruplex complex. Isothermal titration calorimetry data confirmed that Chelerythrine-quadruplex complex formation is thermodynamically favourable. Results of quantative RT-PCR experiment in combination with luciferase assay showed that Chelerythrine treatment to MCF7 breast cancer cells effectively down regulated transcript level of all three genes, suggesting that Chelerythrine efficiently binds to in cellulo quadruplex motifs. MD simulation provides the molecular picture showing interaction between Chelerythrine and G-quadruplex. Binding of Chelerythrine with BCL2, VEGFA and KRAS genes involved in evasion, angiogenesis and self sufficiency of cancer cells provides a new insight for the development of future therapeutics against cancer.
authors.affiliation: Department of Biophysics, Bose Institute, Kolkata, WB, India.
authors.forename: Jagannath
authors.initials: J
authors.lastname: Jana
authors.affiliation: Department of Biophysics, Bose Institute, Kolkata, WB, India.
authors.forename: Soma
authors.initials: S
authors.lastname: Mondal
authors.affiliation: Division of Plant Biology, Bose Institute, Kolkata, WB, India.
authors.forename: Payel
authors.initials: P
authors.lastname: Bhattacharjee
authors.affiliation: Department of Biophysics, Bose Institute, Kolkata, WB, India.
authors.forename: Pallabi
authors.initials: P
authors.lastname: Sengupta
authors.affiliation: Cancer Biology and Inflammatory Disorder Division, Kolkata, WB, India.
authors.forename: Tanaya
authors.initials: T
authors.lastname: Roychowdhury
authors.affiliation: Department of Biophysics, Bose Institute, Kolkata, WB, India.
authors.forename: Pranay
authors.initials: P
authors.lastname: Saha
authors.affiliation: Division of Plant Biology, Bose Institute, Kolkata, WB, India.
authors.forename: Pallob
authors.initials: P
authors.lastname: Kundu
authors.affiliation: Department of Biophysics, Bose Institute, Kolkata, WB, India.
authors.forename: Subhrangsu
authors.initials: S
authors.lastname: Chatterjee
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D053119:Benzophenanthridines / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites; D002151:Calorimetry; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D005454:Fluorescence Polarization; D054856:G-Quadruplexes; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter; D011905:Genes, ras; D006801:Humans; D008968:Molecular Conformation; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D059372:Nucleotide Motifs; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013816:Thermodynamics; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D053119:Benzophenanthridines; D019253:Proto-Oncogene Proteins c-bcl-2; D042461:Vascular Endothelial Growth Factor A; C016299:chelerythrine