PubMed Health⌕ Search

Biomedical subjects

R C Coombes

Publications and source records attributed to R C Coombes.

At least 37 records · Page 2Linked to original sources
PubMed2002

Fibroblast growth factor 8 is expressed at higher levels in lactating human breast and in breast cancer.

Fibroblast growth factor 8 can transform NIH3T3 cells and its expression has been found to be associated with breast and prostate cancer. Following our finding that fibroblast growth factor 8 mRNA expression is increased in breast cancer, we have undertaken an immunohistochemistry study of fibroblast growth factor 8 expression in a series of human breast tissues and other normal tissues. Our findings confirm increased expression of fibroblast growth factor 8 in malignant breast tissue but also show significant fibroblast growth factor 8 expression in non-malignant breast epithelial cells. No significant difference in fibroblast growth factor 8 expression was found between different grades of ductal carcinoma, lobular carcinoma and ductal carcinoma in-situ or cancer of different oestrogen receptor, progesterone receptor or nodal status. The highest levels of fibroblast growth factor 8 expression were found in lactating breast tissues and fibroblast growth factor 8 was also detected in human milk. A survey of other normal tissues showed that fibroblast growth factor 8 is expressed in the proliferative cells of the dermis and epithelial cells in colon, ovary fallopian tube and uterus. Fibroblast growth factor 8 appears to be expressed in several organs in man and appears to have an importance in lactation.

Adult↗
PubMed2002

Tamoxifen-related porphyria cutanea tarda.

We report a case of porphyria cutanea tarda (PCT) in a patient with breast cancer following adjuvant tamoxifen. Cessation of tamoxifen resulted in a prompt decline in urinary porphyrins suggestive of a causative role. Tamoxifen is known to be hepatotoxic; however, its association with PCT is unclear. In this report, we discuss the porphyrinogenicity of tamoxifen and potential mechanisms.

Anticarcinogenic Agents↗
PubMed2002

Estrogen receptor beta in breast cancer.

Estrogen is essential for normal growth and differentiation in the mammary gland. It also supports growth of approximately 50% of primary breast cancers. For this reason, removal of estrogen or blocking of its action with the anti-estrogen, tamoxifen, is the main treatment for estrogen receptor alpha (ERalpha)-positive tumors. In 1996, when oncologists became aware of a second ER, ERbeta, there was some doubt as to whether this receptor would be of importance in breast cancer because the clinical consensus was that responsiveness to tamoxifen is related to the presence of ERalpha in breast cancer. Today we know that ERalpha and ERbeta have distinct cellular distributions, regulate separate sets of genes and can oppose each other's actions on some genes. We also know that ERbeta is widely expressed in both the normal and malignant breast and that there are proliferating cells in the breast which express ERbeta. In this review we summarize what is known about ERbeta in breast cancer and examine the possibility that ERbeta-selective ligands may well represent a useful class of pharmacological tools with a novel target, namely proliferating cells expressing ERbeta.

Animals↗
PubMed2001

Estrogen receptors and proliferation markers in primary and recurrent breast cancer.

To elucidate the clinical importance of estrogen receptor (ER) beta in breast cancer, 29 archival primary breast cancer specimens, six locally recurrent cancers, and five benign mammary tumors were examined histochemically for ERalpha, ERbeta and the proliferation markers Ki67 and cyclin A. In benign tumors, most epithelial cells contained ERbeta, but ERalpha was rare. In primary cancers, both ERalpha and ERbeta occurred in epithelial cells, the presence of ERbeta being associated with elevated expression of Ki67 and cyclin A, and ERalpha with decreased levels. Thus, the highest content of proliferation markers was seen in primary cancers that were ERalpha(-) ERbeta(+). Most Ki67-containing cells coexpressed ERbeta, but few showed ERalpha. In locally recurring cancers, ERalpha, ERbeta, and Ki67 were more highly expressed than in the corresponding primary tumors, and many cells containing ERbeta, but few with ERalpha, expressed Ki67. Surprisingly, ERbeta, but not ERalpha, was seen in the stromal cells of both primary and recurrent cancers. Because the response of breast cancers to tamoxifen therapy is correlated with the presence of ERalpha, cancer cells that lack ERalpha but contain ERbeta and proliferation markers represent a novel population of apparently proliferating cells that probably are not targeted by the current antiestrogens. Thus, appropriate ERbeta-specific ligands, perhaps in combination with tamoxifen, may be useful in improving the treatment of breast cancers.

Biomarkers, Tumor↗
PubMed2001

Analysis of estrogen-responsive finger protein expression in benign and malignant human breast.

The estrogen-responsive finger protein (EFP) gene was originally identified in a screen of genomic DNA for genes containing estrogen-response elements (EREs), and its expression was subsequently shown to be estrogen-regulated and correlated with estrogen receptor (ER)alpha-positive tissues in mice. Human chromosomal mapping localized it to 17q23.1, close to BRCA1, in a region frequently lost in breast cancers. Structurally related proteins have been implicated in a variety of important cellular processes, including carcinogenisis. Given that ER is over-expressed in a large proportion of breast cancers, we reasoned that EFP may play a role in mediating the estrogen-dependent progression of breast cancer. We raised anti-sera to EFP and show that EFP is present in the cytoplasm in mammary cell lines and epithelial cells of normal breast tissue. Furthermore, EFP is present in cell culture medium, suggesting that it may be secreted. Immunohistochemistry of paraffin-embedded breast biopsy specimens showed significantly greater levels of EFP in lactating breast and fibroadenomata compared to normal breast (p<0.001 and p = 0.001, respectively), which is likely to be a result of estrogen responsiveness. Levels were reduced in breast cancer (p = 0.02), where no correlation was seen with other immunohistochemical, histopathological or clinical data. The lack of correlation between EFP and ER status of tumors could indicate escape from estrogenic control, pointing to new models of tumor pathogenesis. Increased levels of EFP in lactating breast and the reduction in malignancy suggest a role for EFP in promoting mammary gland differentiation.

Animals↗
PubMed2001

Retroviral infection of the FGF2 gene into MCF-7 cells induces branching morphogenesis, retards cell growth and suppresses tumorigenicity in nude mice.

FGF2 (basic fibroblast growth factor) is a multifunctional growth factor and exhibits diverse function in different cell types. In breast, loss of FGF2 expression is associated with malignant progression. In order to understand the role of FGF2 in maintenance of normal breast structures and control of cell growth, we restored FGF2 expression in the breast cancer cell line MCF-7. The FGF2 retrovirally infected MCF-7 cells (MCF-7.F2.5) not only expressed FGF2 in cytoplasm and nuclei, but also released FGF2 into culture medium both on plastic and in Matrigel conditions. The MCF-7.F2.5 cells formed branches in Matrigel and this effect was abolished by the addition of a neutralising anti-FGF2 antibody or function blocking antibodies to alpha2, alpha3 and beta1 integrins. Furthermore, MCF-7.F2.5 cells lost their ability for anchorage-independent growth in soft agar. When MCF-7 and MCF-7.F2.5 cells were injected into nude mice, there was a 1.6- to 3.2-fold reduction of tumour volume with MCF-7.F2.5 cells in comparison with the parental MCF-7 cells. MCF-7.F2.5 cells also demonstrated a reduction in oestrogen receptor-alpha (ERalpha) both in vitro and in vivo. Our results suggest that introduction of the FGF2 gene into MCF-7 cells altered the malignant tumour cells towards a more benign phenotype in vitro and in vivo.

Animals↗
PubMed2001

Estrogen-receptor-directed neoadjuvant therapy for breast cancer: results of a randomised trial using formestane and methotrexate, mitozantrone and mitomycin C (MMM) chemotherapy.

BACKGROUND: We wanted to determine whether neoadjuvant systemic chemoendocrine therapy guided by the estrogen receptor (ER) status of the primary breast cancer, followed by conventional surgery and/or radiotherapy, reduces local and distant recurrence and improves survival compared with adjuvant treatment given conventionally postoperatively. PATIENTS AND METHODS: Two hundred ten patients with primary breast cancer (T1-T4, N0, N1-2) were randomised to receive treatment with neoadjuvant chemoendocrine therapy or conventional post-operative chemoendocrine therapy. Systemic therapy was based on the estrogen receptor (ER) status of the primary tumour obtained by trucut core biopsy. ER-negative patients received MMM chemotherapy (methotrexate (30 mg/m2), mitozantrone (7 mg/m2) and mitomycin (7 mg/m2) three-weekly for three months and ER-positive patients who were premenopausal received goserelin (3.75 mg monthly), and post menopausal women formestane (250 mg every two weeks) over three months. RESULTS: With a minimum of five years follow-up, there is no evidence of any survival benefit from the pretreatment neoadjuvant therapy regimen, with five year overall survival being 79% +/- 4.7% (neoadjuvant) and 87% +/- 3.4% (adjuvant). Similarly, there was no apparent benefit in terms of disease-free survival. There was, however, a significant reduction in the incidence of distant metastases in responders (4 of 51; 8%) compared with non-responders (17 of 49; 35%) (P < 0.01). There was a reduction in the need for surgery in responding patients with T1 and T2 tumours, since 10 of 74 (14%) had no detectable residual tumour, without any apparent increase in the risk of local or distant recurrence. CONCLUSION: In this study neoadjuvant treatment with endocrine or chemotherapy provided no obvious survival benefit to women with breast cancer. However, it does allow avoidance of surgery in some cases. Also, the patients whose tumours respond to neoadjuvant systemic therapy have a lower incidence of distant metastases after five year follow-up compared to those whose tumours fail to respond.

Adult↗
PubMed2001

Tamoxifen is not detrimental to endothelial function in postmenopausal women with breast cancer.

BACKGROUND: Tamoxifen has mixed estrogen agonist and antagonist properties in estrogen-regulated tissues. Its effect on the cardiovascular system is not well defined. We carried out a study to investigate the effect of tamoxifen on peripheral vascular endothelial function. METHODS: Three groups of postmenopausal women (median age, 56 years; range, 39 to 69 years) with breast cancer were studied. Patients in group 1 (n = 10) were newly diagnosed with breast cancer and studied before and after 4 weeks treatment with tamoxifen. Group 2 women (n = 6) had been receiving long-term tamoxifen (3 to 5 years) and were studied while taking tamoxifen and 4 weeks after stopping it. The final group of 6 subjects were in remission from primary breast cancer and were not receiving or had previously received tamoxifen. Ultrasound assessments of endothelial function were done before and 4 weeks after the initiation or discontinuation of tamoxifen with the nontreatment group acting as control. All ultrasound imaging was made by a single investigator blinded to the therapeutic status of the subject. Brachial artery diameter was measured by ultrasound at baseline and 1 minute after reactive hyperemia. Flow-mediated reactivity (FMR) was defined as percent change in artery diameter from baseline 1 minute after reactive hyperemia. RESULTS: There was no change in FMR in patients before compared with 4 weeks after starting tamoxifen (4.06% +/- 1.44% vs 3.97% +/- 1.20%, respectively, mean +/- standard error of the mean [SEM], P =.97). There was no significant change in FMR on withdrawal from tamoxifen (1.84% +/- 1.98% vs -0.42% +/- 1.44% on tamoxifen vs off tamoxifen, mean +/- SEM, P =.36). FMR in subjects taking tamoxifen was no different from the control group (3.17% +/- 1.05% vs 3.16% +/- 0.91%, respectively, mean +/- SEM, P =.995). CONCLUSIONS: Tamoxifen does not appear to affect endothelial function in the short term in postmenopausal women with breast cancer.

Adult↗
PubMed2001

Trichostatin A is a histone deacetylase inhibitor with potent antitumor activity against breast cancer in vivo.

PURPOSE: Trichostatin A (TSA), an antifungal antibiotic with cytostatic and differentiating properties in mammalian cell culture, is a potent and specific inhibitor of histone deacetylase (HDAC) activity. The purpose of this study was to evaluate the antiproliferative and HDAC inhibitory activity of TSA in vitro in human breast cancer cell lines and to assess its antitumor efficacy and toxicity in vivo in a carcinogen-induced rat mammary cancer model. EXPERIMENTAL DESIGN AND RESULTS: TSA inhibited proliferation of eight breast carcinoma cell lines with mean +/- SD IC(50) of 124.4 +/- 120.4 nM (range, 26.4-308.1 nM). HDAC inhibitory activity of TSA was similar in all cell lines with mean +/- SD IC(50) of 2.4 +/- 0.5 nM (range, 1.5-2.9 nM), and TSA treatment resulted in pronounced histone H4 hyperacetylation. In randomized controlled efficacy studies using the N-methyl-N-nitrosourea carcinogen-induced rat mammary carcinoma model, TSA had pronounced antitumor activity in vivo when administered to 16 animals at a dose of 500 microg/kg by s.c. injection daily for 4 weeks compared with 14 control animals. Furthermore, TSA did not cause any measurable toxicity in doses of up to 5 mg/kg by s.c. injection. Forty-one tumors from 26 animals were examined by histology. Six tumors from 3 rats treated with TSA and 14 tumors from 9 control animals were adenocarcinomas. In contrast, 19 tumors from 12 TSA-treated rats had a benign phenotype, either fibroadenoma or tubular adenoma, suggesting that the antitumor activity of TSA may be attributable to induction of differentiation. Two control rats each had tumors with benign histology. CONCLUSIONS: The present studies confirm the potent dose-dependent antitumor activity of TSA against breast cancer in vitro and in vivo, strongly supporting HDAC as a molecular target for anticancer therapy in breast cancer.

Animals↗
PubMed2000

Two weekly vinorelbine: administration in patients who have received at least two prior chemotherapy regimes for advanced breast cancer.

This study examined the response to and toxicity of two weekly vinorelbine administration in patients with at least two prior chemotherapeutic treatments for advanced breast cancer. This single centre study enrolled 20 patients, 19 of whom had received prior taxane treatment for advanced breast cancer. Taxane treatment was in the form of docetaxel for all but 1 patient who had received paclitaxel. All patients had received two or more prior chemotherapeutic regimes for advanced breast carcinoma, including anthracyclines (epirubicin) in 19 patients. Vinorelbine 25 mg/m2 two weekly was given for 6 months, until disease progression or toxicity precluded further treatment. 5 earlier studied patients started vinorelbine at 25 mg/m2/week; all changed to the two weekly schedule, limiting the incidence and severity of neutropenia. 7 partial responses (PRs) out of 20 assessable patients (35% overall response rate, 95% confidence interval 15-59%) were noted, all PRs occurring in taxane pretreated patients. The median duration of response was 4 months whilst the median time to progression was 2.75 months. Overall, there were 7 neutropenic events (35%) of 2 week median duration, spanning common toxicity criteria (CTC) grades 1-3 in severity. 5 neutropenia cases (25%) occurred in patients whilst on two weekly vinorelbine. 2 cases (10%) required granulocyte colony stimulating factor support, 1 having had febrile neutropenia (52%). One case of thrombocytopenia, neurotoxicity and nausea (each CTC grade 1) were recorded. Although this study involves a small number of cases, these preliminary results suggest that two weekly vinorelbine is effective in heavily pretreated (including taxane pretreated) advanced breast carcinoma. Response is comparable with that of traditionally used weekly regimes, with markedly less toxicity.

Adult↗
PubMed2000

Estrogen receptor alpha in human breast cancer: occurrence and significance.

Estrogens have long been recognized as being important for stimulating the growth of a large proportion of breast cancers. Now it is recognized that estrogen action is mediated by two receptors, and the presence of estrogen receptor alpha (ER alpha) correlates with better prognosis and the likelihood of response to hormonal therapy. Over half of all breast cancers overexpress ER alpha and around 70% of these respond to anti-estrogen (for example tamoxifen) therapy. In addition, the presence of elevated levels of ER alpha in benign breast epithelium appears to indicate an increased risk of breast cancer, suggesting a role for ER alpha in breast cancer initiation, as well as progression. However, a proportion of ER alpha-positive tumors does not respond to endocrine therapy and the majority of those that do respond eventually become resistant. Most resistant tumors remain ER alpha-positive and frequently respond to alternative endocrine treatment, indicative of a continued role for ER alpha in breast cancer cell proliferation. The problem of resistance has resulted in the search for and the development of diverse hormonal therapies designed to inhibit ER alpha action, while research on the mechanisms which underlie resistance has shed light on the cellular mechanisms, other than ligand binding, which control ER alpha function.

Alternative Splicing↗
PubMed2000

Open comparative trial of formestane versus megestrol acetate in postmenopausal patients with advanced breast cancer previously treated with tamoxifen.

The aim of the trial was to compare efficacy and safety of the aromatase inhibitor formestane (250 mg i.m. given every 2 weeks) with the progestin megestrol acetate (160 mg administered orally once daily), as second-line therapy in postmenopausal patients with advanced breast cancer previously treated with tamoxifen. A total of 547 patients were enrolled. Analyses revealed no statistically significant or clinically relevant difference between treatments with respect to time endpoints. In the intent-to-treat analysis, the median values for time to failure and overall survival for formestane were 169 and 561 days, respectively. The corresponding values for megestrol acetate were 169 days and 597 days, respectively. Overall response rates were comparable for formestane and megestrol acetate (16.3% vs 20.3%). Formestane was better tolerated than megestrol acetate. In the megestrol acetate group, cardiovascular events, weight increase, and vaginal haemorrhage were significantly more frequent than in the formestane group. Thus, formestane is a suitable alternative to progestins in patients previously treated with tamoxifen.

Journal Article↗
PubMed2000

Response of circulating tumor cells to systemic therapy in patients with metastatic breast cancer: comparison of quantitative polymerase chain reaction and immunocytochemical techniques.

PURPOSE: We previously developed a quantitative system for the detection of cytokeratin 19 (CK-19) transcripts using reverse transcriptase polymerase chain reaction (PCR) to detect breast carcinoma cells in blood and bone marrow. The aim of this study was to determine the value of this system in monitoring patients with metastatic disease and to compare it with an established immunocytochemical method. PATIENTS AND METHODS: Patients with progressive, locally advanced, and metastatic breast cancer (all stage IV) who were due to start systemic treatment were recruited. Blood samples were analyzed for CK-19 transcripts using quantitative PCR (QPCR) and immunocytochemistry (ICC) throughout their course of treatment. RESULTS: One hundred forty-five blood samples were obtained from 22 patients over 13 months. Seventy-two (49.6%) of these samples were positive by QPCR, and 56 (42%) of 133 were positive by ICC. Of the 133 specimens analyzed by both techniques, 95 (71.4%) had the same results for each, and of the 71 samples that were positive, 40 (56%) were positive by both methods. The relationship between the number of cells detected and the QPCR values was statistically significant (P <.0001). Of the 25 courses of assessable treatment, 17 (68%) of 25 treatment outcomes (either response or disease progression) were reflected by QPCR measurements, and 12 (57%) of 21 were reflected by ICC. During the course of the study, five patients showed a response, and of these, ICC was in agreement in four cases (80%) and QPCR in three cases (60%). Eighteen courses of treatment resulted in progression of the disease; however, only 15 of these were assessable by ICC. ICC was in agreement in eight (53%) of 15 of these cases, and QPCR in 15 (83%) of 18 cases. CONCLUSION: Circulating carcinoma cells are frequently found in patients with metastatic breast cancer. In the majority of patients, cancer cell numbers as evaluated by QPCR or ICC reflected the outcome of systemic treatment.

Adult↗
PubMed2000

Microsatellite alterations plasma DNA of primary breast cancer patients.

The aim of this study was to analyze plasma DNA from primary and metastatic breast cancer cases for tumor-specific alterations and to compare these findings with immunocytochemistry and estimation of cytokeratin 19 (CK19) mRNA for detection of micrometastases. DNA was extracted from plasma, lymphocytes, and microdissected tumor tissue sections obtained from 71 patients with breast cancer and 9 controls. DNA samples were analyzed for loss of heterozygosity (LOH) and/or microsatellite instability (MI) by PCR with two polymorphic markers (DM-1 and D16S400). Reverse transcription-quantitative PCR (QPCR) and immunocytochemistry were used for detection of CK19 mRNA and protein. Breast cancer plasma DNA displayed frequent LOH (31.3%) and MI (11.6%) supported by the same alteration in microdissected tumor DNA. Most notably, 10 of the 39 patients with primary breast cancer showed LOH (n = 6) or MI (n = 4). We compared plasma tumor DNA, plasma and bone marrow QPCR, and blood and bone marrow immunocytochemistry in 32 of the patients with primary cancer. Of these, only one patient had immunocytochemically detectable carcinoma cells in the blood, and three showed abnormally high levels of plasma CK19 mRNA. All four of these patients had plasma DNA alterations. We then compared bone marrow findings: of the 10 primary breast cancers that showed LOH or MI, 6 had elevated CK19 mRNA and 5 had immunocytochemically positive cells. Tumor DNA is readily detectable in plasma of primary and metastatic breast cancer patients, and plasma DNA alterations (LOH and MI) reflect those seen in the tumor. The application of microsatellite analyses to plasma DNA may be useful in assessing tumor burden in breast cancer patients, particularly when combined with QPCR, and is preferable for patients with breast cancer, for whom sequential bone marrow aspiration is undesirable.

Adult↗
PubMed2000

Activation of estrogen receptor alpha by S118 phosphorylation involves a ligand-dependent interaction with TFIIH and participation of CDK7.

Phosphorylation of the estrogen receptor alpha (ERalpha) N-terminal transcription activation function AF1 at serine 118 (S118) modulates its activity. We show here that human ERalpha is phosphorylated by the TFIIH cyclin-dependent kinase in a ligand-dependent manner. Furthermore, the efficient phosphorylation of S118 requires a ligand-regulated interaction of TFIIH with AF2, the activation function located in the ligand binding domain (LBD) of ERalpha. This interaction involves (1) the integrity of helix 12 of the LBD/AF2 and (2) p62 and XPD, two subunits of the core TFIIH. These findings are suggestive of a novel mechanism by which nuclear receptor activity can be regulated by ligand-dependent recruitment of modifying activities, such as kinases.

Amino Acid Motifs↗
PubMed1999

Outcome of primary-breast-cancer patients with micrometastases: a long-term follow-up study.

BACKGROUND: Bone-marrow micrometastases have been found in patients with primary breast cancer. We report long-term follow-up of women with primary breast cancer, diagnosed between 1981 and 1986, who had multiple aspirates taken at the time of initial surgery. METHODS: 350 women with primary breast cancer were examined immunocytochemically with antibody to epithelial membrane antigen. We investigated associations with various prognostic factors as well as the effect of micrometastases on relapse-free survival and overall survival. FINDINGS: At median follow-up of 12.5 years, 151 patients had metastatic disease and 136 patients had died from breast cancer. 10-year relapse-free and overall survival were 43.9% (95% CI 33.4-54.7) and 44.9% (34.2-55.9) in patients with micrometastases, and 62.7% (56.5-68.6) and 65.7% (59.4-71.5) in patients without micrometastases at presentation (p<0.001). For relapse-free survival and overall survival, allowing for tumour size, lymph-node status, and vascular invasion, the effect of micrometastases decreased and was no longer significant, with a hazard ratio of 1.09 (0.74-1.61) for relapse-free survival and 1.21 (0.84-1.75) for overall survival. INTERPRETATION: The presence of bone-marrow micrometastases in patients with primary breast cancer is associated with a shorter relapse-free survival and overall survival, but is not an independent prognostic factor. This immunocytochemical technique may be of value in patients for whom pathological tumour size and lymph-node status are unavailable (ie, patients receiving primary medical treatment).

Adult↗