DMA, a bisbenzimidazole, offers radioprotection by promoting NFκB transactivation through NIK/IKK in human glioma cells
Authors: Vibha Tandon
Atul Ranjan
Navrinder Kaur
Ritu Aneja
Vinod Tiwari
Journal: PLoS ONE (2012)
Discipline: Multidisciplinary
Keywords: Ionizing radiation; radioprotector; DNA damage; glioma cells; DMA
Affiliations: Dr B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India.

Abstract:  Background: Ionizing radiation (IR) exposure often occurs for human beings through occupational, medical, environmental, accidental and/or other sources. Thus, the role of radioprotector is essential to overcome the complex series of overlapping responses to radiation induced DNA damage. Methods and results: Treatment of human glioma U87 cells with DMA (5- {4-methylpiperazin-1-yl}-2-[2'-(3, 4-dimethoxyphenyl)-5'-benzimidazolyl] in the presence or absence of radiation uncovered differential regulation of an array of genes and proteins using microarray and 2D PAGE techniques. Pathway construction followed by relative quantitation of gene expression of the identified proteins and their interacting partners led to the identification of MAP3K14 (NFκB inducing kinase, NIK) as the candidate gene affected in response to DMA. Subsequently, over expression and knock down of NIK suggested that DMA affects NFκB inducing kinase mediated phosphorylation of IKKα and IKKβ both alone and in the presence of ionizing radiation (IR). The TNF-α induced NFκB dependent luciferase reporter assay demonstrated 1.65, 2.26 and 3.62 fold increase in NFκB activation at 10, 25 and 50 µM DMA concentrations respectively, compared to control cells. This activation was further increased by 5.8 fold in drug + radiation (50 µM +8.5 Gy) treated cells in comparison to control. We observed 51% radioprotection in control siRNA transfected cells that attenuated to 15% in siRNA NIK treated U87 cells, irradiated in presence of DMA at 24 h. Conclusions: Our studies show that NIK/IKK mediated NFκB activation is more intensified in cells over expressing NIK and treated with DMA, alone or in combination with ionizing radiation, indicating that DMA promotes NIK mediated NFκB signaling. This subsequently leads to the radioprotective effect exhibited by DMA. 

Retracted: Yes

PubPeer comments:
 Fig 5. Top two panels, control and DBA groups missing loading controls. Several bands within figure are more similar than expected ![file] , 
 Fig 6. Top two panels (Control and DMA groups) missing loading controls. Several bands within gel appear more similar than one would expect ![file] , 
 Fig 6 continued: Apparent cross duplication between figure 5 and 6![file] , 
 Figure 7: Top 2 panels (control and DMA groups) missing loading controls. Several bands appear more similar than would be expected. ![file] , 
 Fig 7 continued: Apparent duplication between figure 7 and figure 5 ![file] , 
 Fig 9: FACS data for two control timepoints appear more similar than would be expected![file] , 
 2020 retraction. https: journals.plos.org plosone article?id=10.1371 journal.pone.0234365 Following the publication of this article [1], concerns were raised regarding Figs 5, 6, 7 and 9: Similarities were noted between 53 out of 68 western blot panels in Figs 5, 6 and 7. These included similarities between: u25cb. u03b2-actin panels representing different conditions. u25cb. IKKu03b1 and IKKu03b2 panels representing different conditions and or different immunoblots. u25cb. P-IKKu03b1 and p-IKKu03b2 panels representing different conditions and or different immunoblots. u25cb. Iu03baBu03b1 panels representing different conditions and or different immunoblots. u25cb. Iu03baBu03b1 panels and IKKu03b2 panels representing different conditions. When adjusting colour levels of the panels listed below, it appears there are more than 6 lanes present in the panel, despite the figure legend indicating only 6 time points. u25cb. Fig 5: p-IKKu03b1 (control), 7 lanes detected, p-IKKu03b2 (control), 7 lanes detected, and p-IKKu03b2 (radiation), 8 lanes detected. u25cb. Fig 6: p-IKKu03b1 (control), 7 lanes detected and p-IKKu03b2 (DMA), 8 lanes detected. u25cb. Fig 7, IKKu03b1 (DMA), 8 lanes detected. In Fig 9A, the DMA (50u00b5M) + Radiation (8.5Gy), 3h panel appears similar to the DMA (50u00b5M) + Radiation (8.5Gy), 6h panel. The authors indicate that the 3h panel was accidentally used to represent the 6h panel and have provided a replacement image for Fig 9A. The authors were first approached by the journal regarding the concerns above in January 2020. The authors informed the journal they would provide the raw data underlying the figures of concern, but as of the time of the publication of this notice, the journal has not yet received the uncropped, original blots underlying Figs 5, 6, and 7. The authors indicated that the delay in providing the underlying data was due to institutional closures. In light of the concerns affecting multiple figure panels that question the reliability of the reported results and conclusions, the PLOS ONE Editors retract this article. VTa did not agree with the retraction and stands behind the published results. NK, AR, VTi, and RA either did not respond directly or could not be reached. Reference 1.Kaur N, Ranjan A, Tiwari V, Aneja R, Tandon V (2012) DMA, a Bisbenzimidazole, Offers Radioprotection by Promoting NFu03baB Transactivation through NIK IKK in Human Glioma Cells. PLoS ONE 7(6): e39426. https: doi.org 10.1371 journal.pone.0039426 ,