Siah1 proteins enhance radiosensitivity of human breast cancer cells

<p>Abstract</p> <p>Background</p> <p>Siah proteins play an important role in cancer progression. We evaluated the effect of Siah1, its splice variants Siah1L and the Siah1 mutant with the RING finger deleted (Siah1ΔR) on radiosensitization of human breast cancer cells.&...

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Main Authors: Engenhart-Cabillic Rita, You An, Fokas Emmanouil, He Hai-Tao, An Han-Xiang
Format: Article
Language:English
Published: BMC 2010-08-01
Series:BMC Cancer
Online Access:http://www.biomedcentral.com/1471-2407/10/403
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author Engenhart-Cabillic Rita
You An
Fokas Emmanouil
He Hai-Tao
An Han-Xiang
author_facet Engenhart-Cabillic Rita
You An
Fokas Emmanouil
He Hai-Tao
An Han-Xiang
author_sort Engenhart-Cabillic Rita
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Siah proteins play an important role in cancer progression. We evaluated the effect of Siah1, its splice variants Siah1L and the Siah1 mutant with the RING finger deleted (Siah1ΔR) on radiosensitization of human breast cancer cells.</p> <p>Methods</p> <p>The status of Siah1 and Siah1L was analysed in five breast cancer cell lines. To establish stable cells, SKBR3 cells were transfected with Siah1, Siah-1L and Siah1ΔR. Siah1 function was suppressed by siRNA in MCF-7 cells. The impact of Siah1 overexpression and silencing on apoptosis, proliferation, survival, invasion ability and DNA repair was assessed in SKBR3 and MCF-7 cells, also in regards to radiation.</p> <p>Results</p> <p>Siah1 and Siah1L mRNA expression was absent in four of five breast cancer cells lines analysed. Overexpression of Siah1 and Siah1L enhanced radiation-induced apoptosis in stable transfected SKBR3 cells, while Siah1ΔR failed to show this effect. In addition, Siah1 and Siah1L significantly reduced cell clonogenic survival and proliferation. Siah1L sensitization enhancement ratio values were over 1.5 and 4.0 for clonogenic survival and proliferation, respectively, pointing to a highly cooperative and potentially synergistic fashion with radiation. Siah1 or Siah1L significantly reduced invasion ability of SKBR3 and suppressed Tcf/Lef factor activity. Importantly, Siah1 siRNA demonstrated opposite effects in MCF-7 cells. Siah1 and Siah1L overexpression resulted in inhibition of DNA repair as inferred by increased levels of DNA double-strand breaks in irradiated SKBR3 cells.</p> <p>Conclusion</p> <p>Our results reveal for the first time how overexpression of Siah1L and Siah1 can determine radiosensitivity of breast cancer cells. These findings suggest that development of drugs augmenting Siah1 and Siah1L activity could be a novel approach in improving tumor cell kill.</p>
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spelling doaj.art-48ae510eddee4c39a887a284ca13b1512022-12-22T02:48:48ZengBMCBMC Cancer1471-24072010-08-0110140310.1186/1471-2407-10-403Siah1 proteins enhance radiosensitivity of human breast cancer cellsEngenhart-Cabillic RitaYou AnFokas EmmanouilHe Hai-TaoAn Han-Xiang<p>Abstract</p> <p>Background</p> <p>Siah proteins play an important role in cancer progression. We evaluated the effect of Siah1, its splice variants Siah1L and the Siah1 mutant with the RING finger deleted (Siah1ΔR) on radiosensitization of human breast cancer cells.</p> <p>Methods</p> <p>The status of Siah1 and Siah1L was analysed in five breast cancer cell lines. To establish stable cells, SKBR3 cells were transfected with Siah1, Siah-1L and Siah1ΔR. Siah1 function was suppressed by siRNA in MCF-7 cells. The impact of Siah1 overexpression and silencing on apoptosis, proliferation, survival, invasion ability and DNA repair was assessed in SKBR3 and MCF-7 cells, also in regards to radiation.</p> <p>Results</p> <p>Siah1 and Siah1L mRNA expression was absent in four of five breast cancer cells lines analysed. Overexpression of Siah1 and Siah1L enhanced radiation-induced apoptosis in stable transfected SKBR3 cells, while Siah1ΔR failed to show this effect. In addition, Siah1 and Siah1L significantly reduced cell clonogenic survival and proliferation. Siah1L sensitization enhancement ratio values were over 1.5 and 4.0 for clonogenic survival and proliferation, respectively, pointing to a highly cooperative and potentially synergistic fashion with radiation. Siah1 or Siah1L significantly reduced invasion ability of SKBR3 and suppressed Tcf/Lef factor activity. Importantly, Siah1 siRNA demonstrated opposite effects in MCF-7 cells. Siah1 and Siah1L overexpression resulted in inhibition of DNA repair as inferred by increased levels of DNA double-strand breaks in irradiated SKBR3 cells.</p> <p>Conclusion</p> <p>Our results reveal for the first time how overexpression of Siah1L and Siah1 can determine radiosensitivity of breast cancer cells. These findings suggest that development of drugs augmenting Siah1 and Siah1L activity could be a novel approach in improving tumor cell kill.</p>http://www.biomedcentral.com/1471-2407/10/403
spellingShingle Engenhart-Cabillic Rita
You An
Fokas Emmanouil
He Hai-Tao
An Han-Xiang
Siah1 proteins enhance radiosensitivity of human breast cancer cells
BMC Cancer
title Siah1 proteins enhance radiosensitivity of human breast cancer cells
title_full Siah1 proteins enhance radiosensitivity of human breast cancer cells
title_fullStr Siah1 proteins enhance radiosensitivity of human breast cancer cells
title_full_unstemmed Siah1 proteins enhance radiosensitivity of human breast cancer cells
title_short Siah1 proteins enhance radiosensitivity of human breast cancer cells
title_sort siah1 proteins enhance radiosensitivity of human breast cancer cells
url http://www.biomedcentral.com/1471-2407/10/403
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