Abstract:
INTRODUCTION:In response to gamma-irradiation (IR)-induced double-strand DNA breaks, cells undergo cell-cycle arrest, allowing time for DNA repair before reentering the cell cycle. G2/M checkpoint activation involves activation of ataxia telangiectasia mutated (ATM)/ATM- and rad3-related (ATR) kinases and inhibition of Cdc25 phosphatases, resulting in inhibition of Cdc2 kinase and subsequent G2/M cell-cycle arrest. Previous studies from our laboratory showed that the G2/M checkpoint activation after IR exposure of MCF-7 breast cancer cells is dependent on the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) signaling. In the present studies, we investigated the role of Ras-related C3 botulinum toxin substrate 1 (Rac1) guanosine triphosphatase (GTPase) in IR-induced G2/M checkpoint response and ERK1/2 activation, as well as in cell survival after IR. METHODS:With Rac1-specific inhibitor, dominant negative mutant Rac1 (N17Rac1) and specific small interfering RNA, the effect of Rac1 on IR-induced G2/M checkpoint response and ERK1/2 activation was examined in human breast cancer cells. In addition, the effect of Rac1 on cell survival after irradiation was assessed by using Rac1-specific inhibitor. RESULTS:IR exposure of MCF-7 breast cancer cells was associated with a marked activation of Rac1 GTPase. Furthermore, inhibition of Rac1 by using specific inhibitor, dominant-negative Rac1 mutant, or specific siRNA resulted in attenuation of IR-induced G2/M arrest and concomitant diminution of IR-induced activation of ATM, ATR, Chk1, and Chk2 kinases, as well as phosphorylation of Cdc2-Tyr15. Moreover, Rac1 inhibition or decreased Rac1 expression also abrogated IR-induced phosphorylation of mitogen-activated protein kinase kinase 1 and 2 (MEK1/2) and ERK1/2. Ultimately, inhibition of Rac1 markedly increased cellular sensitivity to IR exposure, which involves induction of apoptosis. CONCLUSION:Studies in this report suggest that Rac1 GTPase plays an essential role in the activation of IR-induced ERK1/2 signaling and subsequent G2/M checkpoint response. Furthermore, results also support a role for Rac1 in promoting cell survival after irradiation treatment.
journal_name
Breast Cancer Resjournal_title
Breast cancer research : BCRauthors
Yan Y,Greer PM,Cao PT,Kolb RH,Cowan KHdoi
10.1186/bcr3164subject
Has Abstractpub_date
2012-04-11 00:00:00pages
R60issue
2eissn
1465-5411issn
1465-542Xpii
bcr3164journal_volume
14pub_type
杂志文章abstract:INTRODUCTION:Breast cancers can be classified using whole genome expression into distinct subtypes that show differences in prognosis. One of these groups, the basal-like subtype, is poorly differentiated, highly metastatic, genomically unstable, and contains specific genetic alterations such as the loss of tumour prot...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr2142
更新日期:2008-01-01 00:00:00
abstract:BACKGROUND:Full-field digital mammography (FFDM) has largely replaced film-screen mammography in the US. Breast density assessed from film mammograms is strongly associated with breast cancer risk, but data are limited for processed FFDM images used for clinical care. METHODS:We conducted a case-control study nested a...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-016-0715-3
更新日期:2016-05-21 00:00:00
abstract::A series of recent studies have demonstrated that the retinoblastoma tumor suppressor (RB) pathway plays a critical role in multiple clinically relevant aspects of breast cancer biology, spanning early stage lesions to targeted treatment of metastatic disease. In ductal carcinoma in situ, multiple groups have shown th...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr3652
更新日期:2014-05-07 00:00:00
abstract:INTRODUCTION:Surgery is currently the definitive treatment for early-stage breast cancer. However, the rate of positive surgical margins remains unacceptably high. The human sodium iodide symporter (hNIS) is a naturally occurring protein in human thyroid tissue, which enables cells to concentrate radionuclides. The hNI...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr3404
更新日期:2013-03-18 00:00:00
abstract:BACKGROUND:An increasing number of women are evaluated for potential breast cancer and may experience mental distress during evaluation. We aim to assess the risks of psychiatric disorders and cardiovascular diseases during the diagnostic workup of potential breast cancer. METHODS:All women with a new diagnosis of uns...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-019-1232-y
更新日期:2019-12-10 00:00:00
abstract:INTRODUCTION:Classification of breast cancers according to the HER-2 oncogene status is of central importance in the selection of post-surgical therapies. A decrease in the proportion of HER-2-positive breast cancer has been suspected, but no data on the incidence trends at population level have been reported. METHODS...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr2322
更新日期:2009-01-01 00:00:00
abstract:INTRODUCTION:Bisphosphonates are inhibitors of osteoclast-mediated tumor-stimulated osteolysis, and they have become standard therapy for the management of bone metastases from breast cancer. These drugs can also directly induce growth inhibition and apoptosis of osteotropic cancer cells, including estrogen receptor-po...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr1363
更新日期:2006-01-01 00:00:00
abstract::The Breast Cancer Site Group (BCSG) of the National Cancer Institute of Canada (NCIC) Clinical Trials Group (CTG) has conducted a wide variety of clinical trials focussing on large phase III trials of adjuvant chemotherapy, adjuvant hormonal therapy, and optimal delivery of adjuvant radiation therapy. The Group has al...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr979
更新日期:2005-01-01 00:00:00
abstract::Improvements in the detection and treatment of breast cancer have dramatically altered its clinical course and outcome. However, prevention of breast cancer remains an elusive goal. Parity, age of menarche, and age at menopause are major risk factors drawing attention to the important role of the endocrine system in d...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr431
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Women with breast cancer who have multiple affected relatives are more likely to have inherited genetic risk factors for the disease. All the currently known genetic risk factors for breast cancer account for less than half of the average familial risk. Furthermore, the genetic factor(s) underlying an increa...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-017-0825-6
更新日期:2017-03-16 00:00:00
abstract:BACKGROUND:E74-like factor 5 (ELF5) is an epithelial-specific member of the E26 transforming sequence (ETS) transcription factor family and a critical regulator of cell fate in the placenta, pulmonary bronchi, and milk-producing alveoli of the mammary gland. ELF5 also plays key roles in malignancy, particularly in basa...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-015-0666-0
更新日期:2016-01-07 00:00:00
abstract:INTRODUCTION:Matrix metalloproteinase (MMP)-2 is very active at degrading extracellular matrix. It is under the influence of an activator, membrane type 1 MMP (MMP-14), and the tissue inhibitor of metalloproteases (TIMP)-2. We hypothesized that the individual expression of these three markers or their balance may help ...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr1503
更新日期:2006-01-01 00:00:00
abstract:INTRODUCTION:Bcl-2 and Bcl-xL confer resistance to apoptosis, thereby reducing the effectiveness of chemotherapy. We examined the relationship between the expression of Bcl-2 and Bcl-xL and chemosensitivity of breast cancer cells, with the aim of developing specific targeted therapy. METHODS:Four human breast cancer c...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr1323
更新日期:2005-01-01 00:00:00
abstract::Anti-angiogenic therapies have demonstrated their value in the setting of advanced cancer, and are being explored for use in micrometastatic disease. Recent preclinical studies suggest that adjuvant anti-vascular endothelial growth factor (VEGF) therapies may increase the risk of metastasis. How concerning are these p...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr2250
更新日期:2009-01-01 00:00:00
abstract::The concept of 'targeted' therapies implies that such drugs only act on cells that specifically express the particular target, therefore giving rise to a low incidence of side effects. However, targeted therapies currently approved for the treatment of breast cancer have demonstrated a relatively high incidence of car...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr3142
更新日期:2012-06-19 00:00:00
abstract::Preclinical investigations and selected clinical observational studies support an association between higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk. However, the recently updated report from the Institute of Medicine concluded that, for cancer and vitamin D, the evidence was 'inc...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr2846
更新日期:2011-08-16 00:00:00
abstract:BACKGROUND:Vitamin D has been suggested to prevent and improve the prognosis of several cancers, including breast cancer. We have previously shown a U-shaped association between pre-diagnostic serum levels of vitamin D and risk of breast cancer-related death, with poor survival in patients with the lowest and the highe...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-019-1169-1
更新日期:2019-07-29 00:00:00
abstract:INTRODUCTION:Phosphatidylinositol 3-kinase (PI3K) pathway deregulation (that is PIK3CA mutations and/or phosphatase and tensin homolog (PTEN) loss) has been shown to enhance breast cancer cell survival and confer resistance to chemotherapeutic agents. We studied the prognostic and predictive value of PIK3CA mutations a...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-014-0405-y
更新日期:2014-07-24 00:00:00
abstract:BACKGROUND:Black-white disparities in breast cancer incidence rates and birth outcomes raise concerns about potential disparities in the reproductive health of premenopausal breast cancer survivors. We examined the prevalence of preterm birth (PTB), low birthweight (LBW), and small for gestational age (SGA) by breast c...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-017-0803-z
更新日期:2017-01-31 00:00:00
abstract:BACKGROUND:MicroRNAs (miRNAs) regulate gene expression and influence cancer. Primary transcripts of miRNAs (pri-miRNAs) are poorly annotated and little is known about the role of germline variation in miRNA genes and breast cancer (BC). We sought to identify germline miRNA variants associated with BC risk and tumor sub...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-018-0964-4
更新日期:2018-06-05 00:00:00
abstract:BACKGROUND:Developing novel strategies against treatment-resistant triple negative breast cancer (TNBC) cells remains a significant challenge. The ErbB family, including epidermal growth factor receptor (EGFR), plays key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these charac...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-015-0662-4
更新日期:2016-01-12 00:00:00
abstract::Progesterone receptor status is a marker for hormone responsiveness and disease prognosis in breast cancer. Progesterone receptor negative tumours have generally been shown to have a poorer prognosis than progesterone receptor positive tumours. The observed loss of progesterone receptor could be through a range of mec...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr2097
更新日期:2008-01-01 00:00:00
abstract:INTRODUCTION:Tamoxifen, a selective estrogen receptor (ER) modulator, may affect cancer cell survival through mechanisms other than ER antagonism. In the present study, we tested the efficacy of tamoxifen in a panel of ER-negative breast cancer cell lines and examined the drug mechanism. METHODS:In total, five ER-nega...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-014-0431-9
更新日期:2014-09-17 00:00:00
abstract:INTRODUCTION:The aim of this study was to describe breast tumor subtypes by common breast cancer risk factors and to determine correlates of subtypes using baseline data from two pooled prospective breast cancer studies within a large health maintenance organization. METHODS:Tumor data on 2544 invasive breast cancer c...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr2261
更新日期:2009-01-01 00:00:00
abstract:INTRODUCTION:Insulin-like growth factor binding protein-3 (IGFBP-3) differentially modulates breast epithelial cell growth through insulin-like growth factor (IGF)-dependent and IGF-independent pathways and is a direct (IGF-independent) growth inhibitor as well as a mitogen that potentiates EGF (epidermal growth factor...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr963
更新日期:2005-01-01 00:00:00
abstract:BACKGROUND:The BRCA1 c.3331_3334delCAAG founder mutation has been reported in hereditary breast and ovarian cancer families from multiple Hispanic groups. We aimed to evaluate BRCA1 c.3331_3334delCAAG haplotype diversity in cases of European, African, and Latin American ancestry. METHODS:BC mutation carrier cases from...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-020-01341-3
更新日期:2020-10-21 00:00:00
abstract::Accumulating evidence suggests that many cancers, including BRCA1- and BRCA2-associated breast cancers, are deficient in DNA repair processes. Both hereditary and sporadic breast cancers have been found to have significant downregulation of repair factors. This has provided opportunities to exploit DNA repair deficien...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr2566
更新日期:2010-01-01 00:00:00
abstract:BACKGROUND:Full-term pregnancy (FTP) at an early age confers long-term protection against breast cancer. Previously, we reported that a FTP imprints a specific gene expression profile in the breast of postmenopausal women. Herein, we evaluated gene expression changes induced by parity in the breast of premenopausal wom...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/s13058-019-1128-x
更新日期:2019-03-28 00:00:00
abstract:INTRODUCTION:Breast tumor kinase (Brk/protein tyrosine kinase 6 (PTK6)) is a nonreceptor, soluble tyrosine kinase overexpressed in the majority of breast tumors. Previous work has placed Brk downstream of epidermal growth factor receptor (ErbB) activation and upstream of extracellular signal-regulated kinase 5 (ERK5) a...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章
doi:10.1186/bcr2622
更新日期:2010-01-01 00:00:00
abstract::The key to optimising our approach in early breast cancer is to individualise care. Each patient has a tumour with innate features that dictate their chance of relapse and their responsiveness to treatment. Often patients with similar clinical and pathological tumours will have markedly different outcomes and response...
journal_title:Breast cancer research : BCR
pub_type: 杂志文章,评审
doi:10.1186/bcr2238
更新日期:2009-01-01 00:00:00