Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways
<p>Abstract</p> <p>Background</p> <p>Circadian genes continue to gain attention as important transcriptional regulators with the potential to influence a variety of biological pathways, including many cancer-related processes. The core circadian gene cryptochrome 2 (<...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2010-03-01
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| Series: | BMC Cancer |
| Online Access: | http://www.biomedcentral.com/1471-2407/10/110 |
| _version_ | 1811287750534496256 |
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| author | Yi Chun-Hui Stevens Richard G Ba Yue Zheng Tongzhang Hoffman Aaron E Leaderer Derek Zhu Yong |
| author_facet | Yi Chun-Hui Stevens Richard G Ba Yue Zheng Tongzhang Hoffman Aaron E Leaderer Derek Zhu Yong |
| author_sort | Yi Chun-Hui |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Circadian genes continue to gain attention as important transcriptional regulators with the potential to influence a variety of biological pathways, including many cancer-related processes. The core circadian gene cryptochrome 2 (<it>CRY2</it>) is essential for proper circadian timing, and is a key component of the negative arm of the circadian feedback loop. As such, aberrant expression of <it>CRY2 </it>may influence carcinogenic processes and thereby impact cancer susceptibility.</p> <p>Methods</p> <p>We silenced <it>CRY2 </it>in breast cancer cell lines (MCF-7) using small-interfering oligos (siRNA) and measured the impact of <it>CRY2 </it>knockdown on a number of cancer-relevant parameters. Cell cycle distribution, cell viability, and apoptotic response were measured in <it>CRY2 </it>knockdown (<it>CRY2</it>-) and normal (<it>CRY2</it>+) cell populations using flow cytometry in cells with and without exposure to a mutagen challenge. DNA damage accumulation was measured using the single cell gel electrophoresis (comet) assay, and damage was quantified using the Olive tail moment, which considers the amount and distance of DNA migration away from the nucleus, indicative of DNA strand breaks. Expression changes in cancer-relevant transcripts were measured by whole genome microarray. The Student's t-test was used for statistical comparisons, and P-values obtained from the microarray were adjusted for multiple comparisons using the false discovery rate correction, in order to obtain an adjusted Q-value for each observation.</p> <p>Results</p> <p>The comet assay results indicated that upon exposure to the same dose of chemical mutagen, <it>CRY2</it>- cells accumulate significantly more unrepaired DNA damage than <it>CRY2</it>+ cells (P = 0.040), suggesting that <it>CRY2 </it>may be important for DNA repair. In addition, a number of transcripts with relevance for DNA damage repair displayed altered expression following <it>CRY2 </it>silencing. These included <it>BCCIP </it>(Q = 0.002), <it>BCL2 </it>(Q = 0.049), <it>CCND1 </it>(Q = 0.009), <it>CDKN1A </it>(Q < 0.001), <it>GADD45A </it>(Q = 0.002), <it>HERC5 </it>(Q < 0.001), <it>MCM5 </it>(Q = 0.042), <it>PPP1R15A </it>(Q < 0.001), <it>SUMO1 </it>(Q < 0.001), and <it>UBA1 </it>(Q = 0.023). However, no significant influence of <it>CRY2 </it>knockdown on cell cycle distributions, cell cycle checkpoints in response to mutagen challenge, or apoptotic response was detected.</p> <p>Conclusions</p> <p>In total, these data suggest a limited, but potentially important role for <it>CRY2 </it>in the regulation of DNA damage repair and the maintenance of genomic stability. Future investigations may focus on identifying the mechanisms by which <it>CRY2 </it>may regulate the expression of transcripts with known relevance for carcinogenesis.</p> |
| first_indexed | 2024-04-13T03:23:56Z |
| format | Article |
| id | doaj.art-5de2eb41a7ae492c927aeafa7db50790 |
| institution | Directory Open Access Journal |
| issn | 1471-2407 |
| language | English |
| last_indexed | 2024-04-13T03:23:56Z |
| publishDate | 2010-03-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cancer |
| spelling | doaj.art-5de2eb41a7ae492c927aeafa7db507902022-12-22T03:04:42ZengBMCBMC Cancer1471-24072010-03-0110111010.1186/1471-2407-10-110Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathwaysYi Chun-HuiStevens Richard GBa YueZheng TongzhangHoffman Aaron ELeaderer DerekZhu Yong<p>Abstract</p> <p>Background</p> <p>Circadian genes continue to gain attention as important transcriptional regulators with the potential to influence a variety of biological pathways, including many cancer-related processes. The core circadian gene cryptochrome 2 (<it>CRY2</it>) is essential for proper circadian timing, and is a key component of the negative arm of the circadian feedback loop. As such, aberrant expression of <it>CRY2 </it>may influence carcinogenic processes and thereby impact cancer susceptibility.</p> <p>Methods</p> <p>We silenced <it>CRY2 </it>in breast cancer cell lines (MCF-7) using small-interfering oligos (siRNA) and measured the impact of <it>CRY2 </it>knockdown on a number of cancer-relevant parameters. Cell cycle distribution, cell viability, and apoptotic response were measured in <it>CRY2 </it>knockdown (<it>CRY2</it>-) and normal (<it>CRY2</it>+) cell populations using flow cytometry in cells with and without exposure to a mutagen challenge. DNA damage accumulation was measured using the single cell gel electrophoresis (comet) assay, and damage was quantified using the Olive tail moment, which considers the amount and distance of DNA migration away from the nucleus, indicative of DNA strand breaks. Expression changes in cancer-relevant transcripts were measured by whole genome microarray. The Student's t-test was used for statistical comparisons, and P-values obtained from the microarray were adjusted for multiple comparisons using the false discovery rate correction, in order to obtain an adjusted Q-value for each observation.</p> <p>Results</p> <p>The comet assay results indicated that upon exposure to the same dose of chemical mutagen, <it>CRY2</it>- cells accumulate significantly more unrepaired DNA damage than <it>CRY2</it>+ cells (P = 0.040), suggesting that <it>CRY2 </it>may be important for DNA repair. In addition, a number of transcripts with relevance for DNA damage repair displayed altered expression following <it>CRY2 </it>silencing. These included <it>BCCIP </it>(Q = 0.002), <it>BCL2 </it>(Q = 0.049), <it>CCND1 </it>(Q = 0.009), <it>CDKN1A </it>(Q < 0.001), <it>GADD45A </it>(Q = 0.002), <it>HERC5 </it>(Q < 0.001), <it>MCM5 </it>(Q = 0.042), <it>PPP1R15A </it>(Q < 0.001), <it>SUMO1 </it>(Q < 0.001), and <it>UBA1 </it>(Q = 0.023). However, no significant influence of <it>CRY2 </it>knockdown on cell cycle distributions, cell cycle checkpoints in response to mutagen challenge, or apoptotic response was detected.</p> <p>Conclusions</p> <p>In total, these data suggest a limited, but potentially important role for <it>CRY2 </it>in the regulation of DNA damage repair and the maintenance of genomic stability. Future investigations may focus on identifying the mechanisms by which <it>CRY2 </it>may regulate the expression of transcripts with known relevance for carcinogenesis.</p>http://www.biomedcentral.com/1471-2407/10/110 |
| spellingShingle | Yi Chun-Hui Stevens Richard G Ba Yue Zheng Tongzhang Hoffman Aaron E Leaderer Derek Zhu Yong Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways BMC Cancer |
| title | Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways |
| title_full | Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways |
| title_fullStr | Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways |
| title_full_unstemmed | Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways |
| title_short | Phenotypic effects of the circadian gene Cryptochrome 2 on cancer-related pathways |
| title_sort | phenotypic effects of the circadian gene cryptochrome 2 on cancer related pathways |
| url | http://www.biomedcentral.com/1471-2407/10/110 |
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