Mutation Induced Conformational Changes in Genomic DNA from Cancerous K562 Cells Influence Drug-DNA Binding Modes

Abstract

Normal human genomic DNA (N-DNA) and mutated DNA (M-DNA) from K562 leukemic cells show different thermodynamic properties and binding affinities on interaction with anticancer drugs; adriamycin (ADR) and daunomycin (DNM). Isothermal calorimetric thermograms representing titration of ADR/DNM with N-DNA and M-DNA on analysis best fitted with sequential model of four and three events respectively. From Raman spectroscopy it has been identified that M-DNA is partially transformed to A form owing to mutations and N-DNA on binding of drugs too undergoes transition to A form of DNA. A correlation of thermodynamic contribution and structural data reveal the presence of different binding events in drug and DNA interactions. These events are assumed to be representative of minor groove complexation, reorientation of the drug in the complex, DNA deformation to accommodate the drugs and finally intercalation. Dynamic light scattering and zeta potential data also support differences in structure and mode of binding of N and M DNA. This study highlights that mutations can manifest structural changes in DNA, which may influence the binding efficacy of the drugs. New generation of drugs can be designed which recognize the difference in DNA structure in the cancerous cells instead of their biochemical manifestation.

In vitro label‐free screening of chemotherapeutic drugs using Raman microspectroscopy: Towards a new paradigm of spectralomics

“…It should be noted that, PLSR over the high concentration range, up to 50 μM, (Figure A) results in a spectral profile which is similar to those of DOX and ACT (Figure ) exhibiting strong features at 785 cm −1 (DNA backbone O─P─O) and 813 cm −1 (RNA O─P─O phosphodiester band stretching), while regression over the lower concentration up to the IC 50 of 1.2 ± 0.2 μM showed a decrease in features at 728, 830 and 1425 cm −1 , related to DNA B form and an increase in features at 668 and 675 cm −1 , related to DNA A form, indicative of conformational changes due to partial transition of the DNA B form to DNA A form due to Cisp binding .…”

Probing the action of a novel anti-leukaemic drug therapy at the single cell level using modern vibrational spectroscopy techniques

“…When a cell enters apoptosis, the DNA shifts to a more disordered state, and the DNA signal in an infrared spectrum typically decreases 46 . A shift in the DNA band can also be observed in cells which have been treated with a drug known to intercalate with DNA, whose mode of action is such that base pairing is interrupted and unravelling from orderly B-DNA to the more disordered A-DNA form occurs 47 .…”

Molecular Spectroscopic Markers of DNA Damage

“…They showed the interaction between anticancer drugs (adriamycin and daunomycin) and DNA. The Raman results indicated that the mutated DNA remained partially transformed to the A-DNA form, owing to mutations, while the genomic DNA changed its conformation upon the interaction with the drug [47]. Wood et al studied the interaction between few platinum drugs and DNA.…”