Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Emerging evidence indicates that the tumor microenvironmental stress of hypoxia can induce genetic instability in cancer cells. We and others have found that the expression levels of key genes within the DNA mismatch repair (MMR) and homologous recombination (HR) pathways are coordinately repressed by hypoxia. These decreases are associated with functional impairments in both MMR and HR repair under hypoxic conditions, and thus they represent a possible mechanistic explanation for the observed phenomenon of hypoxia-induced genetic instability. In parallel, studies also indicate that several DNA damage response factors are activated in response to hypoxia and subsequent reoxygenation, including ATM/ATR, Chkl/Chk2 and BRCA1. Taken together, these findings reveal that hypoxia induces a unique cellular stress response involving an initial, acute DNA damage response to hypoxia and reoxygenation, followed by a chronic response to prolonged hypoxia in which selected DNA repair pathways are coordinately suppressed. In this review, we discuss these pathways and the possible mechanisms involved, as well as the consequences for genetic instability and tumor progression within the tumor microenvironment.
Cancer Metastasis Rev 2007 Jun
PMID:Regulation of DNA repair in hypoxic cancer cells. 1741 27

Metastasis-associated tumor antigen 1 (MTA1), a component of the nucleosome remodeling and deacetylating (NuRD) complex is routinely upregulated in several cancers. In the present study, we investigated the potential role of MTA1 in BRCA1 transcriptional repression and subsequent chromosomal instability. MTA1-NuRD complex was found to negatively regulate BRCA1 transcription by physically associating with an atypical estrogen-responsive element (ERE) on the BRCA1 promoter. Moreover, MTA1 and HDAC complex recruited to the ERE of BRCA1 promoter in an ER alpha-dependent manner. Accordingly, BRCA1 protein levels were enhanced by silencing of either MTA1 expression or by treatment with the specific histone deacetylase inhibitor trichostatin A. MTA1's strong repressive effects on BRCA1 expression was supported by our observation that cells stably overexpressing MTA1 showed centrosome amplification which has been long implicated as a phenotype for BRCA1 repression. Accordingly, overexpression of BRCA1 in cells stably over expressing MTA1 resulted in restoration of normal centrosome numbers. Together, these findings strongly implicate MTA1 in the transcriptional repression of BRCA1 leading to abnormal centrosome number and chromosomal instability.
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PMID:MTA1-mediated transcriptional repression of BRCA1 tumor suppressor gene. 1792 32

The majority of BRCA1-associated breast cancers are basal cell-like, which is associated with a poor outcome. Using a spontaneous mouse mammary tumor model, we show that platinum compounds, which generate DNA breaks during the repair process, are more effective than doxorubicin in Brca1/p53-mutated tumors. At 0.5 mg/kg of daily cisplatin treatment, 80% primary tumors (n = 8) show complete pathologic response. At greater dosages, 100% show complete response (n = 19). However, after 2 to 3 months of complete remission following platinum treatment, tumors relapse and become refractory to successive rounds of treatment. Approximately 3.8% to 8.0% (mean, 5.9%) of tumor cells express the normal mammary stem cell markers, CD29(hi)24(med), and these cells are tumorigenic, whereas CD29(med)24(-/lo) and CD29(med)24(hi) cells have diminished tumorigenicity or are nontumorigenic, respectively. In partially platinum-responsive primary transplants, 6.6% to 11.0% (mean, 8.8%) tumor cells are CD29(hi)24(med); these populations significantly increase to 16.5% to 29.2% (mean, 22.8%; P < 0.05) in platinum-refractory secondary tumor transplants. Further, refractory tumor cells have greater colony-forming ability than the primary transplant-derived cells in the presence of cisplatin. Expression of a normal stem cell marker, Nanog, is decreased in the CD29(hi)24(med) populations in the secondary transplants. Top2A expression is also down-regulated in secondary drug-resistant tumor populations and, in one case, was accompanied by genomic deletion of Top2A. These studies identify distinct cancer cell populations for therapeutic targeting in breast cancer and implicate clonal evolution and expansion of cancer stem-like cells as a potential cause of chemoresistance.
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PMID:Cancer stem cells contribute to cisplatin resistance in Brca1/p53-mediated mouse mammary tumors. 1845 Nov 50

The BRCA/RAD51 complex of tumor suppressor genes plays a major role in the DNA damage response. In this explorative study, BRCA1, BRCA2, and RAD51 mRNA expression was quantified in highly defined laser microdissected tissue samples of simple adenomas, adenocarcinomas of the mammary gland, and their lymph node metastases by real-time quantitative reverse transcription polymerase chain reaction. Expression levels in the tumors were normalized to the geometric mean of 3 housekeeping genes and quantified relative to normal mammary epithelium of the same dog. In adenomas, mRNA expression was reduced for BRCA1 (6/10 dogs, 60%), BRCA2 (4/10 dogs, 40%), and RAD51 (4/10, 40%). In adenocarcinomas BRCA1 expression varied with increased expression in 3 of 10 (30%) dogs and no differences in 7 of 10 (70%) dogs when compared with normal mammary gland. BRCA2 and RAD51 were overexpressed in 5 of 10 (50%) and 6 of 10 (60%) of adenocarcinomas, respectively. An overexpression of RAD51 and BRCA2 was found in 8 of 10 (80%) and 5 of 10 (50%) of the lymph node metastases, respectively. Direct comparison of primary tumors and metastases revealed increased mRNA expression of BRCA1 (2/10 dogs, 20%), BRCA2 (2/10 dogs, 20%), and RAD51 (3/10 dogs, 30%) in lymph node metastases. Taken together, the results suggest that RAD51 is upregulated in the majority of lymph node metastases of canine mammary tumors. Further experimental studies are needed to clarify whether these changes in gene expression are a direct carcinogenetic stimulus or a protective response due to genetic instability during tumor progression.
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PMID:Increased expression of BRCA2 and RAD51 in lymph node metastases of canine mammary adenocarcinomas. 1917 91

Abnormalities of chromosome 17, recognised over two decades ago to be important in tumorigenesis, often occur in breast cancer. Changes of specific loci on chromosome 17 including ERBB2 amplification, P53 loss, BRCA1 loss, and TOP2A amplification or deletion are known to have important roles in breast-cancer pathophysiology. Numerical aberrations of chromosome 17 are linked to breast-cancer initiation and progression, and possibly to treatment response. However, the clinical importance of chromosome 17 anomalies, in particular the effect on ERBB2 protein expression, is unknown. Reports are conflicting regarding the association of copy gain of chromosome 17 (polysomy 17) with strong ERBB2 protein expression in the absence of true ERBB2 gene amplification. Copy-number anomalies in chromosome 17 seem to be common in tumours that show discrepant ERBB2 expression and in tumours with discordant ERBB2-protein and ERBB2 gene copy number measurements. The mechanisms of ERBB2 dosage changes-gene amplification versus chromosome gain and loss-probably differ in primary and metastatic disease; however, a correction for chromosome 17 copy-number is necessary to completely distinguish between these mechanisms. A better understanding of how polysomy 17 affects gene-copy number and protein expression will help to select patients who will respond to therapies targeting ERBB2 and other protein products of chromosome 17 loci.
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PMID:Breast cancer and aneusomy 17: implications for carcinogenesis and therapeutic response. 1926 Dec 55

Risk-reducing salpingo-oophorectomy (RRSO) is an effective prophylactic procedure for women with mutations in BRCA1 or BRCA2 genes, both of which confer an increased lifetime risk for ovarian, tubal, peritoneal, and breast cancer. In addition to lowering this risk, RRSO also offers the opportunity to detect occult early-stage fallopian tube or ovarian carcinoma. The differential diagnosis of occult tubal/ovarian cancer includes a spectrum of benign tubal and ovarian alterations and also occult metastatic breast cancer, although only rare cases of the latter have been reported in RRSO. Neoadjuvant breast cancer chemotherapy may contribute to diagnostic difficulty due to treatment-induced cytologic alterations. With the aim of elucidating features which may help with differential diagnosis, this study reports the incidence and pathologic features of benign ovarian alterations, benign ovarian tumors, and occult primary and metastatic malignancies in prophylactic oophorectomies from 108 women with a BRCA mutation and from 35 women with other strong risk factors for hereditary breast/ovarian carcinoma. We direct particular emphasis on morphologic features of primary ovarian lesions that may mimic occult metastatic breast cancer. We also evaluate histologic alterations due to neoadjuvant breast cancer chemotherapy in the ovary and fallopian tube of patients who received such treatment immediately preceding RRSO. Comparison is made to ovarian metastases of breast cancer in our hospital-based population of breast cancer patients, none of whom underwent RRSO. Overall, 69% of RRSO patients had a personal history of breast cancer. Neoadjuvant breast cancer chemotherapy was administered in 15%. Occult primary carcinoma occurred in 7 (6.5%) BRCA patients (5 in fallopian tube, 1 in fallopian tube and ovary, 1 in ovary). Ovarian metastasis of breast cancer occurred in 1 (1%) BRCA patient undergoing RRSO and in up to a similar proportion (0.8%) of the hospital-based population of breast cancer patients. The metastasis in the RRSO patient was clinically occult, unilateral, 0.2 cm, and demonstrated mild atypia without mitoses. Abundant foamy, vacuolated cytoplasm due to neoadjuvant chemotherapy exposure was notable. In contrast, ovarian metastases in the non-RRSO population were all clinically detected, bilateral, large, and exhibited well-developed malignant cytologic features. None of the normal cell types in the ovary or tube demonstrated any cytologic alterations in RRSO patients who received neoadjuvant chemotherapy. The main morphologic mimics of metastasis with superimposed chemotherapy-induced alterations in RRSO were stromal hyperthecosis (n=8), nodular hyperthecosis (n=2), adrenal rests (n=3), hilus cell nodules (n=43), and hilus cell hyperplasia (n=4). Occult primary ovarian carcinoma was reliably distinguished from ovarian metastases of breast cancer by WT-1+, p53+, mammaglobin-, GCDPF-immunoprofile. These results demonstrate that evaluation of RRSO specimens requires awareness of a spectrum of ovarian lesions which may mimic occult primary or metastatic carcinoma; awareness of the masquerading effects of neoadjuvant chemotherapy; and awareness of the potential morphologic differences between occult metastatic breast cancer in RRSO and non-RRSO specimens.
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PMID:Ovarian pathology in risk-reducing salpingo-oophorectomies from women with BRCA mutations, emphasizing the differential diagnosis of occult primary and metastatic carcinoma. 1944 Jan 48

Male breast cancer accounts for around 1% of all breast cancer cases, but the incidence has increased over the past 25 years. The rarity of this entity precludes prospective randomized clinical trials. Although breast carcinoma in both genders share certain characteristics, notable differences have emerged. Familial cases usually have BRCA2 rather than BRCA1 mutations. Klinefelter syndrome is the strongest risk factor for developing male breast carcinoma. Men tend to be diagnosed at an older age than women. Presentation is usually a painless lump, but is often late, with more than 40% of individuals having stage III or IV disease. When survival is adjusted for age at diagnosis and stage of disease, outcomes for male and female patients with breast cancer is similar. Surgery is usually mastectomy with axillary clearance or sentinel node biopsy. Because 90% of tumors are hormonal receptor positive, tamoxifen is standard adjuvant therapy. Indications for radiotherapy and chemotherapy are similar to female breast cancer. For metastatic disease, hormonal therapy is the main treatment, but chemotherapy can also provide palliation.
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PMID:Male breast cancer. 2019 84

The size of a breast cancer at diagnosis has conventionally been thought of as a fundamental and critical determinant of clinical outcome. However, the tendency of some subtypes of breast cancer to behave aggressively, despite being small (</=1 cm in diameter), questions the premise that cancer size should always be considered in treatment decisions. Although there is an association between tumor size and lymph-node involvement for most tumor types, this pattern is not invariable. We speculate that the uncoupling of tumor size, lymph-node status and prognosis in some subtypes of breast cancers might reflect an underlying disproportionate relationship between the number of cancer cells with metastatic potential and the size of the cancer. Alternatively, some small cancers might harbor cells that are inherently aggressive and are likely to metastasize. These observations have implications for the screening and treatment of breast cancers, particularly for women with basal-like and BRCA1-related breast cancers.
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PMID:Tumor size and survival in breast cancer--a reappraisal. 2030 6

BRCA1 functions as a tumor suppressor; recent work suggests that BRCA1 may also induce cell cycle arrest to allow for DNA repair. We hypothesized that BRCA1 expression in prostate tumor tissue may be associated with prostate cancer progression through regulation of the cell cycle. We used immunohistochemistry to evaluate BRCA1 protein expression in archival tumor samples from 393 prostate cancer cases in the Physicians' Health Study. The men were followed prospectively from diagnosis to development of metastases and mortality. Fifteen percent of tumors stained positive for BRCA1. BRCA1-positive tumors had substantially increased tumor proliferation index compared with negative tumors (47.0 Ki67-positive nuclei versus 10.3, P = 0.0016) and were more likely to develop lethal cancer compared with BRCA1-negative tumors (hazard ratio, 4.6; 95% confidence interval, 2.4-8.7). These findings strengthen the hypothesis that BRCA1 plays a role in cell cycle control and show that BRCA1 is a marker of clinical prostate cancer prognosis. Cancer Res; 70(8); 3136-9. (c)2010 AACR.
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PMID:Immunohistochemical expression of BRCA1 and lethal prostate cancer. 2038 72

While a dominant inheritance of breast cancer (vertical inheritance) is well known, less is known about a possible recessive inheritance (horizontal inheritance). In a clinical series of 1676 breast cancer patient's family history was scored as vertical (grandmother-aunt-mother-sister-daughter) or horizontal (sister-sister) and related to histopathological tumor type, presence of germline mutations, bilaterality, multifocality, screening, parity, hormone replacement therapy (HRT) use and age at diagnosis. Prognosis was estimated by also adding tumor size, lymph node status, distant metastases and hormone receptor status at diagnosis into a Cox proportional hazard model. Excluding mutations carriers, a horizontal family history (5% of all cases) was significantly associated with tubular tumor type [OR = 3.87(1.44-10.41)]. A vertical family history (23% of all cases) was significantly related to tumor multifocality [OR = 2.30(1.51-3.50)], tumor bilaterality [OR = 2.08(1.44-3.00)] and screening detection [OR = 1.50(1.10-2.05)]. No significant difference in survival could be seen between patients with none, horizontal or vertical family history. However, germline mutation carriers (BRCA1/2, TP53 or CDKN2A, present in 0.95% of the cases) had a significantly worse survival. Screening detected cases, HRT ever users and patients with estrogen receptor positive tumors had a significantly better survival adjusting for age at diagnosis, tumor size, lymph node status and presence of distant metastases at diagnosis. Factors associated with a horizontal family history were found, defining a possible phenotype for a recessive inheritance: tubular breast cancer.
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PMID:Can a phenotype for recessive inheritance in breast cancer be defined? 2054 70


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