Determination of growth inhibitory action point of interferon \gamma on WISH cells in cell cycle progression and the window of responsiveness of the cells to the interferon

Vashistha, Surabhi and Patil, Supriya and Joshi, Chirag and Ajitkumar, Parthasarathi (2007) Determination of growth inhibitory action point of interferon \gamma on WISH cells in cell cycle progression and the window of responsiveness of the cells to the interferon. In: Cytokine, 37 (2). pp. 108-118.

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Abstract

We had earlier shown that human foetal epithelial cells (WISH), growth-inhibited by interferon \gamma (IFN\gamma), were reversibly detained at a point prior to DNA synthesis. In the present study, we determined the window of action of IFNc in the G1 phase duration and the exact point of detention of WISH cells in cell cycle progression with respect to the known points of detention by the inhibitors of DNA replication initiation (aphidicolin and carbonyl diphosphonate) and of activation of replication protein A (6-dimethylaminopurine), of which RPA activation being the earlier event compared to DNA replication initiation in cell cycle progression. WISH cells, which were released from IFN\gamma-induced arrest, permeabilised and exposed independently to these inhibitors show that IFNc detains WISH cells prior to initiation of DNA synthesis. Further, exposure of IFN\alpha-synchronized (at G0/G1) or mimosine-synchronized (at G1/S) WISH cells to IFN\gamma, which was added at different time points post-release from the synchronizing agent, showed that the cells were promptly responsive to the growth inhibitory action of IFN\gamma only during the first 11 h in G1 phase. Taken together, these results suggest that IFNc inhibits growth of WISH cells by detaining them at a point prior to initiation of DNA synthesis and that the IFN acts within the first 11 h in G1 phase of the cell cycle.

Item Type:	Journal Article
Publication:	Cytokine
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Interferon c,Cell cycle;G1, G1/S;WISH cells;Interferon a, Mimosine
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	01 Jul 2008
Last Modified:	19 Sep 2010 04:46
URI:	http://eprints.iisc.ac.in/id/eprint/14716

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