Indian Journal of Medical Research

: 2014  |  Volume : 139  |  Issue : 3  |  Page : 349--370

Cytogenomics of hexavalent chromium (Cr6+) exposed cells: A comprehensive review

Akanksha Nigam1, Shivam Priya1, Preeti Bajpai2, Sushil Kumar1 
1 Environmental Carcinogenesis Division, CSIR-Indian Institute of Toxicology Research, Lucknow, India
2 Department of Biotechnology, Integral University, Lucknow, India

Correspondence Address:
Sushil Kumar
Environmental Carcinogenesis Division, CSIR-Indian Institute of Toxicology Research Mahatma Ganghi Marg, Post Box 80, Lucknow 226 026

The altered cellular gene expression profile is being hypothesized as the possible molecular basis navigating the onset or progress of various morbidities. This hypothesis has been evaluated here in respect of Cr 6+ induced toxicity. Several studies using gene microarray show selective and strategic dysregulations of cellular genes and pathways induced by Cr 6+ . Relevant literature has been reviewed to unravel these changes in different test systems after exposure to Cr 6+ and also to elucidate association if any, of the altered cytogenomics with Cr 6+ induced toxicity or carcinogenicity. The aim was to verify the hypothesis for critical role of altered cytogenomics in onset of Cr 6+ induced biological / clinical effects by identifying genes modulated commonly by the toxicant irrespective of test system or test concentrations / doses, and by scrutinizing their importance in regulation of the flow of mechanistically linked events crucial for resultant morbidities. Their probability as biomarkers to monitor the toxicant induced biological changes is speculative. The modulated genes have been found to cluster under the pathways that manage onset of oxidative stress, DNA damage, apoptosis, cell-cycle regulation, cytoskeleton, morphological changes, energy metabolism, biosynthesis, oncogenes, bioenergetics, and immune system critical for toxicity. In these studies, the identity of genes has been found to differ remarkably; albeit the trend of pathways«SQ» dysregulation has been found to remain similar. We conclude that the intensity of dysregulation of genes or pathways involved in mechanistic events forms a sub-threshold or threshold level depending upon the dose and type (including speciation) of the toxicant, duration of exposure, type of target cells, and niche microenvironment of cells, and the intensity of sub-threshold or threshold level of the altered cytogenomics paves way in toxicant exposed cells eventually either to opt for reversal to differentiation and growth, or to result in toxicity like dedifferentiation and apoptosis, respectively.

How to cite this article:
Nigam A, Priya S, Bajpai P, Kumar S. Cytogenomics of hexavalent chromium (Cr6+) exposed cells: A comprehensive review.Indian J Med Res 2014;139:349-370

How to cite this URL:
Nigam A, Priya S, Bajpai P, Kumar S. Cytogenomics of hexavalent chromium (Cr6+) exposed cells: A comprehensive review. Indian J Med Res [serial online] 2014 [cited 2021 Jun 24 ];139:349-370
Available from:;year=2014;volume=139;issue=3;spage=349;epage=370;aulast=Nigam;type=0