The tumor suppressor BRCA1 is a translational regulator
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ABSTRACT:
PROVIDER: PRJNA490557 | ENA |
REPOSITORIES: ENA
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Project description:BRCA1 inactivation is a hallmark of familial breast cancer, often encountered in aggressive triple negative breast cancers. BRCA1 is a tumor suppressor with known functions in DNA repair, transcription regulation, cell cycle control, and apoptosis. In the present study, we demonstrate that BRCA1 is also a translational regulator. Based on the combination of RNA-binding protein immunoprecipitation and microarray analysis, as well as polysome profiling, we identified a subset of mRNAs translationally regulated by BRCA1 and coding for proteins whose functions play major role in cancer. We found that the level of these key proteins is similarly controlled in human mammary tumors according to their BRCA1-status. Therefore, our results propose translational control as a novel molecular mechanism with clinical relevance through which BRCA1 is a tumor suppressor.
2020-05-21 | GSE119886 | GEO
Project description:Expression of the tumor suppressor protein BRCA1 is frequently lost in breast cancer patients, and the loss of its expression is associated with disruption of various critical functions in cells and cancer development. In the present study, we demonstrated that microarray analysis of cells with tumor suppressor candidate 4 (TUSC4) knockdown indicated critical changes such as cell cycle, cell death pathways and a global impact to cancer development. More importantly, we observed a clear cluster pattern of TUSC4-knockdown gene profiles with established homologous recombination (HR) repair defect signature. Additionally, TUSC4 protein can physically interact with E3 ligase Herc2 and prevents BRCA1 degradation via ubiquitination pathway. Knockdown of TUSC4 expression enhanced BRCA1 polyubiquitination, leading to BRCA1 protein degradation and a marked reduction in HR repair efficiency. Notably, ectopic expression of TUSC4 effectively suppressed the proliferation, invasion, and colony formation of breast cancer cells in vitro and tumorigenesis in vivo. Furthermore, knockdown of TUSC4 expression transformed normal mammary epithelial cells and enhanced the sensitivity of U2OS cells to the treatment of poly(ADP-ribose) polymerase inhibitors. Therefore, TUSC4 may act as a bona fide tumor suppressor by regulating BRCA1 protein stability and function in breast cancer. Two groups of samples are included: 1.U2OS-shcontrol 2.U2OS-shTUSC4 knockdown. Gene expression profiles of U2OS-shTUSC4 cells were compared to that of parental U2OS-shcontrol cells.
2014-08-21 | E-GEOD-60535 | biostudies-arrayexpress
Project description:The tumor suppressor BRCA1 is a translational regulator
| PRJEB28622 | ENA
Project description:BRCA1, a well-known breast and ovarian cancer susceptibility gene with multiple interacting partners, is predicted to have diverse biological functions. However, to date its only well-established role is in the repair of damaged DNA and cell cycle regulation. In this regard, the etiopathological study of low penetrant variants of BRCA1 provides an opportunity to uncover its other physiologically important functions. Using this rationale, we studied the R1699Q variant of BRCA1, a potentially moderate risk variant, and found that it does not impair DNA damage repair but abrogates the repression of miR-155, a bona fide oncomir. We further show that in the absence of functional BRCA1, miR-155 is up-regulated in BRCA1-deficient mouse mammary epithelial cells, human and mouse BRCA1-deficienct breast tumor cell lines as well as tumors. Mechanistically, we found that BRCA1 represses miR-155 expression via its association with HDAC2, which deacetylates H2A and H3 on the miR-155 promoter. Finally, we show that over-expression of miR-155 accelerates whereas the knockdown of miR-155 attenuates the growth of tumor cell lines in vivo. Taken together, our findings demonstrate a new mode of tumor suppression by BRCA1 and reveal miR-155 as a potential therapeutic target for BRCA1-deficient tumors. This SuperSeries is composed of the following subset Series: GSE31611: Expression data from embryoid body with BRCA1 mutation [mRNA] GSE31636: Expression data from embryoid body with BRCA1 mutation [miRNA] Refer to individual Series
2011-12-31 | E-GEOD-31637 | biostudies-arrayexpress
Project description:Expression of the tumor suppressor protein BRCA1 is frequently lost in breast cancer patients, and the loss of its expression is associated with disruption of various critical functions in cells and cancer development. In the present study, we demonstrated that microarray analysis of cells with tumor suppressor candidate 4 (TUSC4) knockdown indicated critical changes such as cell cycle, cell death pathways and a global impact to cancer development. More importantly, we observed a clear cluster pattern of TUSC4-knockdown gene profiles with established homologous recombination (HR) repair defect signature. Additionally, TUSC4 protein can physically interact with E3 ligase Herc2 and prevents BRCA1 degradation via ubiquitination pathway. Knockdown of TUSC4 expression enhanced BRCA1 polyubiquitination, leading to BRCA1 protein degradation and a marked reduction in HR repair efficiency. Notably, ectopic expression of TUSC4 effectively suppressed the proliferation, invasion, and colony formation of breast cancer cells in vitro and tumorigenesis in vivo. Furthermore, knockdown of TUSC4 expression transformed normal mammary epithelial cells and enhanced the sensitivity of U2OS cells to the treatment of poly(ADP-ribose) polymerase inhibitors. Therefore, TUSC4 may act as a bona fide tumor suppressor by regulating BRCA1 protein stability and function in breast cancer.
2014-08-21 | GSE60535 | GEO
Project description:BRCA1, a well-known breast and ovarian cancer susceptibility gene with multiple interacting partners, is predicted to have diverse biological functions. However, to date its only well-established role is in the repair of damaged DNA and cell cycle regulation. In this regard, the etiopathological study of low penetrant variants of BRCA1 provides an opportunity to uncover its other physiologically important functions. Using this rationale, we studied the R1699Q variant of BRCA1, a potentially moderate risk variant, and found that it does not impair DNA damage repair but abrogates the repression of miR-155, a bona fide oncomir. We further show that in the absence of functional BRCA1, miR-155 is up-regulated in BRCA1-deficient mouse mammary epithelial cells, human and mouse BRCA1-deficienct breast tumor cell lines as well as tumors. Mechanistically, we found that BRCA1 represses miR-155 expression via its association with HDAC2, which deacetylates H2A and H3 on the miR-155 promoter. Finally, we show that over-expression of miR-155 accelerates whereas the knockdown of miR-155 attenuates the growth of tumor cell lines in vivo. Taken together, our findings demonstrate a new mode of tumor suppression by BRCA1 and reveal miR-155 as a potential therapeutic target for BRCA1-deficient tumors. This SuperSeries is composed of the SubSeries listed below.
2011-12-31 | GSE31637 | GEO
Project description:AXL is a putative tumor suppressor and dormancy regulator in prostate cancer
| PRJNA487645 | ENA
Project description:Follistatin is a folliculogenesis regulating protein that has been found in relatively high concentration in the female ovarian tissues. Follistatin acts as an antagonist to the function of Activin, which is often found elevated in ovarian carcinogenesis and thus presents a possibility for therapeutic intervention in controlling ovarian cancer. Most of the ovarian cancer occurs in its ovarian surface epithelium (OSE) cells. Although breast cancer susceptibility gene 1 (BRCA1) is a known tumor suppressor for breast cancer but its role in ovarian cancer is beginning to unfold. We have shown that in ovarian carcinoma cells (SKOV3), stable overexpression of BRCA1 stimulates Follistatin secretion and simultaneously downregulates Activin expression. Moreover, knock down of BRCA1 in immortalized OSE (IOSE) cells from human ovarian tissue demonstrates downregulation of Follistatin secretion with simultaneous up regulation of Activin expression. IOSE cells generated from an ovarian cancer patient with BRCA1 mutation failed to secrete Follistatin in the medium. Our results indicate a novel function for BRCA1 in the form of regulation of the expression of Follistatin in the ovarian cells. 3 treatments vs 3 controls
2011-07-02 | E-GEOD-30296 | biostudies-arrayexpress
Project description:In this study, we identify leucyl-tRNA synthetase (LARS) as a breast tumor suppressor. To identify the mechanism underlying LARS-mediated breast tumor suppression, we conducted TMT-proteomics in PyMT mouse tumors with monoallelic genetic deletion of LARS in the mammary tumor compartment. The analyses implicate LARS as a regulator of leucine-rich protein translation resulting in downregulation of candidate leucine-rich tumor suppressor genes.
2022-01-10 | PXD026609 | Pride
Project description:BRCA1 inactivation is a hallmark of familial breast cancer, often associated with aggressive triple negative breast cancers. BRCA1 is a tumor suppressor with known functions in DNA repair, transcription regulation, cell cycle control, and apoptosis. In the present study, we demonstrate that BRCA1 is also a translational regulator. We previously showed that BRCA1 was implicated in translation regulation. Here, we asked whether translational control could be a novel function of BRCA1 that contributes to its tumor suppressive activity. A combination of RNA-binding protein immunoprecipitation, microarray analysis, and polysome profiling, was used to identify the mRNAs that were specifically deregulated under BRCA1 deficiency. Western blot analysis allowed us to confirm at the protein level the deregulated translation of a subset of mRNAs. A unique and dedicated cohort of patients with documented germ-line BRCA1 pathogenic variant statues was set up, and tissue microarrays with the biopsies of these patients were constructed and analyzed by immunohistochemistry for their content in each candidate protein. Here, we show that BRCA1 translationally regulates a subset of mRNAs with which it associates. These mRNAs code for proteins involved in major programs in cancer. Accordingly, the level of these key proteins is correlated with BRCA1 status in breast cancer cell lines and in patient breast tumors. ADAT2, one of these key proteins, is proposed as a predictive biomarker of efficacy of treatments recently recommended to patients with BRCA1 deficiency. This study proposes that translational control may represent a novel molecular mechanism with potential clinical impact through which BRCA1 is a tumor suppressor.
| S-EPMC7226996 | biostudies-literature