BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene

The BRCA1 gene is associated with hereditary breast and ovarian cancers. BRCA1 fits the model of a classic tumor suppressor gene, a hypothesis supported by recent work demonstrating that expression of BRCAi inhibits growth of breast and ovarian cancer cell lines. The present study was designed to te...

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Main Authors: Abhay Kumar, Christine Kn.ott, Kristine Kuus-Reichel, Mohammad S. Saedi
Format: Article
Language:English
Published: Elsevier 1999-11-01
Series:Neoplasia: An International Journal for Oncology Research
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1476558699800128
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author Abhay Kumar
Christine Kn.ott
Kristine Kuus-Reichel
Mohammad S. Saedi
author_facet Abhay Kumar
Christine Kn.ott
Kristine Kuus-Reichel
Mohammad S. Saedi
author_sort Abhay Kumar
collection DOAJ
description The BRCA1 gene is associated with hereditary breast and ovarian cancers. BRCA1 fits the model of a classic tumor suppressor gene, a hypothesis supported by recent work demonstrating that expression of BRCAi inhibits growth of breast and ovarian cancer cell lines. The present study was designed to test the potential of BRCAi to reverse the transforming activity of the ras oncogene. The v-Ha ras oncogene was cloned downstream of the retrovirus LTR and stably expressed in Rat-1 cells (Rat-1/ras). Rat-1/ras (R/R) cells were fully transformed as indicated by change in morphology, colony formation in soft-agarose and tumor induction in nude mice. BRCAi was stably expressed in R/R cells under the CMV promoter (R/R-BRCA1). The expression of ras and BRCAi was confirmed by Western blot using monoclonal antibodies (mAbs) specific to ras and BRCA1, respectively. R/R-BRCA1 cells grew slower than the negative control, which was R/R cells transfected with vector alone (R/R-pCEP4). R/R-BRCA1 cells generated ~5 to 10 times less colonies in a soft-agarose assay compared to the negative control. When injected into nude mice, R/RBRCA1 cells exhibited a delayed onset of tumorigenesis and generated smaller tumors compared to R/R or R/RpCEP4 cells. These data strongly suggest that BRCA1 partially reverses the transforming activity of the v-Ha ras oncogene indicating that BRCA1 can bypass the effects of the v-Ha ras oncogene on cell growth. BRCA1, therefore, may be used in therapy of tumors arising due to activation of v-Ha ras oncogene.
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spelling doaj.art-a5a4ce92b326495cbaf0cafc593d3e722022-12-22T03:07:48ZengElsevierNeoplasia: An International Journal for Oncology Research1476-55861522-80021999-11-011541742310.1038/sj.neo.7900058BRCA1 Partially Reverses the Transforming Activity of the ras OncogeneAbhay KumarChristine Kn.ottKristine Kuus-ReichelMohammad S. SaediThe BRCA1 gene is associated with hereditary breast and ovarian cancers. BRCA1 fits the model of a classic tumor suppressor gene, a hypothesis supported by recent work demonstrating that expression of BRCAi inhibits growth of breast and ovarian cancer cell lines. The present study was designed to test the potential of BRCAi to reverse the transforming activity of the ras oncogene. The v-Ha ras oncogene was cloned downstream of the retrovirus LTR and stably expressed in Rat-1 cells (Rat-1/ras). Rat-1/ras (R/R) cells were fully transformed as indicated by change in morphology, colony formation in soft-agarose and tumor induction in nude mice. BRCAi was stably expressed in R/R cells under the CMV promoter (R/R-BRCA1). The expression of ras and BRCAi was confirmed by Western blot using monoclonal antibodies (mAbs) specific to ras and BRCA1, respectively. R/R-BRCA1 cells grew slower than the negative control, which was R/R cells transfected with vector alone (R/R-pCEP4). R/R-BRCA1 cells generated ~5 to 10 times less colonies in a soft-agarose assay compared to the negative control. When injected into nude mice, R/RBRCA1 cells exhibited a delayed onset of tumorigenesis and generated smaller tumors compared to R/R or R/RpCEP4 cells. These data strongly suggest that BRCA1 partially reverses the transforming activity of the v-Ha ras oncogene indicating that BRCA1 can bypass the effects of the v-Ha ras oncogene on cell growth. BRCA1, therefore, may be used in therapy of tumors arising due to activation of v-Ha ras oncogene.http://www.sciencedirect.com/science/article/pii/S1476558699800128BRCA1breast cancertumor suppressorrasoncogene
spellingShingle Abhay Kumar
Christine Kn.ott
Kristine Kuus-Reichel
Mohammad S. Saedi
BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene
Neoplasia: An International Journal for Oncology Research
BRCA1
breast cancer
tumor suppressor
ras
oncogene
title BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene
title_full BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene
title_fullStr BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene
title_full_unstemmed BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene
title_short BRCA1 Partially Reverses the Transforming Activity of the ras Oncogene
title_sort brca1 partially reverses the transforming activity of the ras oncogene
topic BRCA1
breast cancer
tumor suppressor
ras
oncogene
url http://www.sciencedirect.com/science/article/pii/S1476558699800128
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AT mohammadssaedi brca1partiallyreversesthetransformingactivityoftherasoncogene