Search PubMed⌕ Search

Biomedical subjects

A Hanby

Publications and source records attributed to A Hanby.

At least 37 records · Page 2Linked to original sources
PubMed1999

Comparative genomic hybridization of breast tumors stratified by histological grade reveals new insights into the biological progression of breast cancer.

How does breast cancer progress? There is evidence both to support (S. W. Duffy et al., Br. J. Cancer, 64: 1133-1138, 1991; R. Rajakariar et al., Br. J. Cancer, 71: 150-154, 1995) and refute (M. Hakama et al., Lancet, 345: 221-224, 1995; R. R. Millis et al., Eur. J. Cancer, 34: 548-553, 1998) the hypothesis of dedifferentiation; the theory that as breast cancers grow they evolve from well differentiated (grade I) to poorly differentiated (grade III) tumors. We provide evidence to support the view that the majority of grade I tumors do not progress to grade III tumors. Comparative genomic hybridization was used to screen entire genomes of a large sample (40 grade I and 50 grade III) of invasive ductal breast carcinomas, stratified by grade. We found distinct genetic differences between grade I and grade III tumors. Significantly, we found that 65% of grade I tumors lost the long arm of chromosome 16 compared with only 16% of grade III tumors. This pattern of loss leads us to conclude that the majority of grade I tumors do not progress to grade III tumors. These findings have important implications because they suggest that different breast tumor grades may have distinct molecular origins, pathogenesis, and behavior and, therefore, potentially present distinct molecular targets for research and treatment.

Breast Neoplasms↗
PubMed1999

Imaging protein kinase Calpha activation in cells.

Spatially resolved fluorescence resonance energy transfer (FRET) measured by fluorescence lifetime imaging microscopy (FLIM), provides a method for tracing the catalytic activity of fluorescently tagged proteins inside live cell cultures and enables determination of the functional state of proteins in fixed cells and tissues. Here, a dynamic marker of protein kinase Calpha (PKCalpha) activation is identified and exploited. Activation of PKCalpha is detected through the binding of fluorescently tagged phosphorylation site-specific antibodies; the consequent FRET is measured through the donor fluorophore on PKCalpha by FLIM. This approach enabled the imaging of PKCalpha activation in live and fixed cultured cells and was also applied to pathological samples.

3T3 Cells↗
PubMed1999

An alpha2,3 sialyltransferase (ST3Gal I) is elevated in primary breast carcinomas.

The MUC1 mucin is expressed on the luminal surface of most simple epithelial cells but in carcinomas, especially those of the breast and ovary, MUC1 is upregulated and aberrantly glycosylated. MUC1 contains a large amount of O-linked glycans which, in the mucin expressed by normal mammary epithelial cells, consist mainly of core 2 based structures carrying polylactosamine chains. However, the mucin expressed by breast carcinomas has shorter side-chains, often consisting of sialylated core 1 (Galbeta1-3GalNAc). in situ hybridization of primary breast tissue showed that a sialyltransferase (ST3Gal I), responsible for adding sialic acid to core 1 thereby terminating chain extension, is elevated in primary breast carcinomas when compared to normal or benign tissue. Furthermore, the level of mRNA expression encoding ST3Gal I is correlated to the intensity of staining seen with the antibody SM3, which specifically recognises underglycosylated, tumour associated MUC1. Thus, the aberrant glycosylation of MUC1 seen in breast carcinomas appears to be due, at least in part, to the elevation of ST3Gal I.

Breast Neoplasms↗
PubMed1999

Differential expression of keratins 10, 17, and 19 in normal cervical epithelium, cervical intraepithelial neoplasia, and cervical carcinoma.

AIM: To examine the value of immunohistochemistry in defining a keratin profile to aid cervical histopathological diagnosis. METHODS: Immunohistochemical localisation of keratins 17, 10, and 19 was studied in 268 cervical biopsies from 216 women including normal epithelia (with and without human papilloma virus), low and high grade cervical intraepithelial neoplasia, and invasive carcinoma. The percentage of positive immunostaining was scored using a Kontron MOP videoplan image analyser. RESULTS: All major categories of cervical epithelia expressed these keratins to varying degrees. The median percentage of immunostaining for keratin 10 was 40% in normal tissue compared with just 1% in invasive carcinoma (p < 0.0001). The medians for keratin 17 were 0% in the normal group and 80% in carcinomas (p < 0.0001). By contrast, there was no significant difference in staining for keratin 19. Using a combination of the keratin 10 and 17 percentages, it was possible to separate the carcinomas from the benign conditions with a sensitivity of 100% and a specificity of 93%. Further analyses within the groups revealed more extensive staining for keratins 10 and 19 in reserve cell hyperplasia, immature squamous metaplasia, and congenital transformation zone. CONCLUSIONS: The morphological variety within the cervix is reflected, in part, by distinct keratin patterns. There are striking differences in the patterns of keratins 10 and 17 between infiltrating squamous carcinoma and normal cervical epithelia.

Biomarkers, Tumor↗
PubMed1998

Comparative analysis of integrins in vitro and in vivo in uveal and cutaneous melanomas.

Changes in integrin expression have been shown to be important for the growth and metastatic capacity of melanoma cells. In this study, we have examined the expression of alphav integrins by three uveal and four cutaneous malanoma lines. No lines expressed alphavbeta6 and only TXM13, a cutaneous line, expressed alphavbeta8. All lines expressed alphavbeta5 and alphavbeta3 (four out of four cutaneous, two out of three uveal) or avpl (OM431, an uveal line). Thus, OM431 is the second uveal melanoma we have described that expresses alphavbeta1 and this, we report again, functions as an alternative vitronectin/fibronectin receptor. Subcutaneous growth of cell lines in athymic mice correlated with an alphavbeta3-positive, alphavbeta1 -negative phenotype. Analysis of clinical material from cutaneous melanoma showed that although alphav expression was increased in 88% of metastases, this could not all be explained by up-regulation of alphavbeta3, with only 2 out of eight skin metastases expressing this heterodimer. Using antibody SZ.21, which as we report here works in archival material, only 1 out of 15 uveal metastases expressed detectable beta3. Thus, acquisition of alphavbeta3 expression, which has been implicated in cutaneous melanoma progression, may not be required for development of metastases from uveal melanoma or indeed for skin, as distinct from lymph node, metastases of cutaneous melanoma.

Animals↗
PubMed1998

Interstitial laser photocoagulation of normal lung parenchyma in rats.

BACKGROUND: Management of peripheral lung tumours may be risky in patients with poor lung function or in the elderly. A new possibility is interstitial laser photocoagulation (ILP) in which tumours are gently coagulated using thin laser fibres placed percutaneously under radiological guidance. This could have a useful palliative role in selected patients, but to be safe the effects on normal lung parenchyma must first be understood. This paper describes the creation and healing of ILP lesions in the normal rat lung. METHODS: ILP was performed using single laser fibres placed percutaneously in the left lung of normal rats under general anaesthetic with radiological guidance (laser power 1-3 W at 805 nm, treatment time 250-1000 s). The lesion size and healing were studied in rats killed at times from three days to six months after treatment, the bursting pressure was measured, and any complications noted. RESULTS: Zones of necrosis up to 12 mm in diameter were produced, the size depending on the laser power and treatment time. Histological examination showed typical thermal effects with complete healing with fibrosis by two months. The effect was very localised with remarkably little effect on the structure and function of the rest of the lung. Adverse effects in the lung parenchyma only occurred if the ILP lesion involved the hilar vessels or the oesophagus, causing pulmonary congestion and perforation, respectively. Pneumothorax was seen in 6% of cases. CONCLUSIONS: ILP with a single fibre can produce a localised zone of necrosis in normal lung parenchyma which heals safely and which has little effect on the rest of the lung. Further study of this technique using multiple fibres in a larger animal model is warranted to see if it is feasible and safe to produce a large enough volume of necrosis to be of value in the treatment of small peripheral lung tumours in patients who are unsuitable for surgery or palliative radiotherapy.

Animals↗
PubMed1998

Stromelysin 3: an independent prognostic factor for relapse-free survival in node-positive breast cancer and demonstration of novel breast carcinoma cell expression.

Stromelysin 3 (ST3) is a matrix metalloproteinase implicated in mammary carcinoma progression. To date, localization of ST3 expression in breast cancer by in situ hybridization and immunocytochemistry has shown that the expression of the enzyme is limited to only the stromal fibroblasts surrounding the cancer cells. We have immunostained a large group of ductal carcinoma in situ and invasive breast carcinomas using a monoclonal antibody (5ST-4A9) raised against the hemopexin-like domain of human ST3. We show that invasive lobular carcinomas express significantly less ST3 than invasive ductal carcinomas (IDCs) (P = 0.002). We also show, for the first time, that certain breast carcinoma cells that have undergone a degree of epithelial-to-mesenchymal transition, the so-called metaplastic carcinomas, can express ST3 mRNA and protein, which may in part explain the increased metastatic propensity seen in a number of these tumors. In addition, patients with IDC who had moderate to strong ST3 levels had significantly shorter disease-free survival than those with negative or weak ST3 levels (P = 0.02). Furthermore, in node-positive IDC patients, multivariate analysis revealed that ST3 level was a strong, independent prognostic parameter for disease-free survival (P = 0.005).

Adult↗
PubMed1997

The localization of the insulin-like growth factor receptor 1 (IGFR-1) in benign and malignant breast tissue.

Insulin-like growth factors (IGFs) play an important role in normal cellular growth and development and have been implicated in the regulation of tumour growth. Two receptors are recognized, IGFR-1 and IGFR-2, of which one, IGFR-1, is a transmembrane heterodimer structurally similar to the insulin receptor. Studies using ligand-binding assays have suggested that the proportion of human breast carcinomas expressing IGFR-1 varies between 39 and 93 per cent and all suggest a lower level of IGFR-1 expression in benign mammary epithelia. As there is this variation between studies and since no study appears to have examined the immunohistochemical localization of IGFR-1 within breast tissue, a series of 79 infiltrating ductal carcinomas, 11 infiltrating lobular carcinomas, three cases of pure ductal carcinoma in situ (DCIS), seven fibroadenomas, and eight normal breast specimens have been studied utilizing the monoclonal antibody alpha IR3. IGFR-1 localized to the epithelial component of 90 per cent of the carcinomas, with only cytoplasmic (21 per cent), only membrane (5 per cent), or a mixture of both cytoplasmic and membrane (64 per cent) staining patterns. In some tumours, distinct basolateral distribution of the receptor was observed. Invasive lobular carcinoma showed significantly less labelling than ductal (P = 0.0009). There was a significant correlation between the level of IGFR-1 immunostaining with both oestrogen receptor (P < 0.001) and progesterone receptor (P = 0.0018) positivity within the malignant group. All normal mammary epithelium showed strong labelling, which was often at an intensity matching that of the most strongly labelled carcinoma and occasionally visualized as basolateral staining of the luminal cells. Weak to moderate staining of endothelial cells was also observed. It is concluded that IGFR-1 immunoreactivity is found in the majority of breast carcinomas, where it correlates most closely with oestrogen receptor status. The high intensity labelling of normal cells seen in this study contrasts with the low levels inferred from ligand-binding-based techniques and emphasizes the importance of the morphological approach in the investigation of novel molecules.

Breast↗
PubMed1997

The expression of Ki-S1 and BCL-2 and the response to primary tamoxifen therapy in elderly patients with breast cancer.

Ki-S1, a marker of proliferation, and bcl-2, the gene product of which is an antagonist of apoptosis, have been measured in 51 ER-positive primary breast cancers before and during tamoxifen treatment and then related to clinical response. Both markers were detected in the majority of tumours before treatment and, quantitatively, initial expression of Bcl-2 protein, but not Ki-S1, was significantly related to the percentage reduction in tumour volume as assessed by ultrasound. Staining for both markers was lower in post treatment samples than in those taken prior to treatments, but concordant decreases in staining indices were seen in only 11 of the 51 tumours. The results demonstrate, using clinical material, that the response to tamoxifen may involve changes in proliferation and/or susceptibility to cell-death.

Aged↗
PubMed1997

Allele loss, replication errors and loss of expression of E-cadherin in colorectal cancers.

BACKGROUND: Loss of E-cadherin expression has been implicated in the development of invasive characteristics in colorectal carcinomas. Failure to express E-cadherin may result from mutations of the E-cadherin gene (HSECAD). AIMS: To examine the correlation between E-cadherin expression and genetic changes at HSECAD; and to examine differences in E-cadherin expression and genetic changes at HSECAD between three different groups of colorectal cancer--replication error positive (RER+) sporadic cancers, RER--sporadic cancers and ulcerative colitis associated cancers. SUBJECTS AND METHODS: Sixty eight colorectal cancers (22 RER+ sporadic cancers, 32 RER- sporadic cancers and 14 ulcerative colitis associated cancers) were studied using immunohistochemistry and for allele loss at the HSECAD locus. Exon 16 of HSECAD contains several mononucleotide repeat tracts which are very similar to microsatellite repeats and which may be susceptible to replication errors (manifest as new alleles). All cases were also examined for new alleles in exon 16. RESULTS: Absent or decreased E-cadherin protein expression was found in 27 (38%) of 68 colorectal cancers and the pattern of expression did not differ significantly among the three tumour groups. Allele loss occurred at HSECAD in four (10%) of 40 informative cancers and there were no differences between the three subgroups. New alleles at exon 16 were detected in three (14%) of 22 RER+ tumours; no new alleles were detected in RER- or ulcerative colitis associated cancers. Overall, there was no correlation between allelic loss or exon 16 replication errors and immunohistochemical E-cadherin expression. CONCLUSIONS: (1) Loss of E-cadherin expression probably does not occur as a result of mutation at the HSECAD locus in colorectal cancers. (2) There is no difference in the frequency of loss of heterozygosity at HSECAD among RER+, RER- and ulcerative colitis associated colorectal cancers.

Alleles↗
PubMed1996

Clinico-pathological features and p53 expression in left-sided sporadic colorectal cancers with and without microsatellite instability.

Defects in mismatch repair (MMR) can result in the development of a 'mutator phenotype', manifest as an increase in DNA replication errors (RERs). Patients with hereditary non-polyposis colorectal cancer (HNPCC) have germline mutations in MMR genes. These patients develop carcinomas of the colon and other specific sites at a significantly earlier age than patients with sporadic carcinomas. RERs are found in the cancers from patients with HNPCC and have been demonstrated in 10-20 per cent of sporadic colorectal cancers (CRCs). Loss of MMR may simply accelerate tumour development, but it is also possible that these tumours follow a different carcinogenetic pathway from tumours with intact MMR. In particular, it has been suggested that p53 mutations occur less often in RER-positive (RER+) sporadic colorectal cancers. In this study, the clinico-pathological features and frequency of p53 overexpression in 17 left-sided RER+ CRCs were compared with 35 left-sided RER- CRCs. No differences were found in the age and tumour stage at presentation, mucinous differentiation, or Jass prognostic grouping between these two types of CRC. Thirteen out of 17 (76 per cent) RER+ and 19/35 (54 per cent) RER- tumours showed overexpression of p53, a non-significant difference (chi 2 test). Although some previous studies have suggested differences in the clinico-pathological features and p53 expression of RER+ and RER- right-sided CRCs, our results show that these differences do not exist in left-sided cancers.

Aged↗
PubMed1995

Human papillomavirus testing in primary cervical screening.

Several studies have examined the role of tests for human papillomavirus (HPV) in screening for cervical cancer but as yet the relevance is unclear. We looked at HPV testing for types 16, 18, 31, and 33 on material taken at the time of a cervical smear in 2009 eligible women having routine screening. Women with any degree of dyskaryosis or high levels of one of these HPV types were referred for colposcopy. 44% of the cervical intraepithelial neoplasia (CIN) lesions of grade 2/3 detected had negative cytology and were found only by HPV testing. A further 22% of the CIN 2/3 lesions were positive for HPV but showed only borderline or mild cytological changes. The positive predictive value of HPV testing was 42%, which was similar to that for moderate dyskaryosis. HPV types 16 and 31 were more sensitive and specific for CIN 2/3 than were types 18 or 33. However, 25% of the CIN 2/3 lesions were not detected by these four HPV tests. We suggest that HPV testing could usefully augment but not replace conventional cytology. These results should stimulate a much larger randomised trial to assess the impact of these improved CIN 2/3 detection rates on the subsequent incidence of invasive cancer.

Adult↗
PubMed1994

Growth of primary human acute lymphoblastic and myeloblastic leukemia in SCID mice.

The in vivo growth of 8 human primary acute lymphoblastic (ALL) and 17 primary acute myeloblastic (AML) cell populations was investigated in severe combined immunodeficient (SCID) mice. Bone marrow (BM) or peripheral blood (PB) samples, either fresh or cryopreserved, were implanted i.v. into irradiated SCID mice. The cells from 5/8 patients with ALL resulted in engraftment with systemic proliferation and dissemination leading to morbidity and mortality of the animals within 12-18 weeks from implantation. In contrast, none of the 17 AML samples resulted in sustained engraftment. Four of the 5 engrafted ALL populations have been successfully passaged into fresh recipients and phenotypic and karyotypic characteristics remain unaltered. The data presented indicate that the SCID mouse may be a useful model for studying the pathogenesis of ALL and may also enable the development and investigation of new therapies for this disease.

Adult↗
PubMed1993

Levels of matrix metalloproteases in bladder cancer correlate with tumor grade and invasion.

We have used quantitative zymography to measure levels of the type IV collagenases matrix metalloproteinase (MMP)-9 and MMP-2 in 42 biopsies of transitional cell carcinoma and in 7 biopsies of normal bladder. Mean levels of MMP-9 were significantly higher in tumor compared with normal samples (P = 0.08). Levels of MMP-9 and active MMP-2 increased with tumor grade (test for trend, P = 0.002 and P = 0.05, respectively). Levels of MMP-9 and activated MMP-2 were also higher in invasive tumors than in superficial ones (P = 0.001 and P = 0.008, respectively). In situ hybridization studies showed that the mRNAs for both MMP-2 and MMP-9 were located chiefly in the stroma rather than epithelial tumor cells and were concentrated at the interface between the two tissues.

Carcinoma, Transitional Cell↗
PubMed1992

Integrins and their accessory adhesion molecules in mammary carcinomas: loss of polarization in poorly differentiated tumors.

The integrins are alpha beta heterodimeric transmembrane proteins mediating cell-substratum as well as cell-cell interactions. To identify the pattern of expression of the beta 1, beta 3, and beta 4 integrins and their accessory adhesion molecules in relation to the malignant phenotype of invasive breast cancer, we performed an immunohistochemical study for the alpha 2 beta 1 (VLA-2), alpha 6 beta 1 (VLA-6), alpha v and alpha v beta 3 (vitronectin receptor), alpha 6 beta 4, carcinoembryonic antigen, and carcinoembryonic antigen-related molecules in a series of 37 invasive breast carcinomas. All integrin chains examined showed similar patterns in nonneoplastic breast tissue, with strong membrane staining of the myoepithelial cells and weak to moderate staining on the basolateral surfaces of the luminal cells. We found that downregulation of the alpha 2 chain of VLA-2 occurs more frequently in poorly differentiated grade III invasive ductal carcinomas (IDCs) (P = .048). Loss of alpha 6 beta 4 seems also to occur more frequently in grade III IDC (seven of 11 cases, 63.6%) than in grade I/II IDC (two of eight cases, 25%), although this did not reach statistical significance. Carcinoembryonic antigen and carcinoembryonic antigen-related antigens, which are known to function as accessory adhesion molecules, were found mainly in the cytoplasm of neoplastic cells and there was reduced membrane polarization in poorly organized tumors. In contrast the alpha v beta 3, vitronectin receptor heterodimer recognized by the 23C6 monoclonal antibody was weak or absent in normal breast epithelium, and was weakly expressed in two of 19 (10%) IDCs and in nine of 18 (50%) invasive lobular carcinomas (P = .008). However, the alpha v chain detected with the antibody 13C2 was weakly to moderately expressed on nonneoplastic epithelium and at a similar intensity in 13 of 19 IDCs and 15 of 17 invasive lobular carcinomas, suggesting that in IDC the alpha v chain may be associated with a different beta chain (possibly beta 1 or beta 5). No correlation between integrin expression and estrogen/progesterone receptor status was found. These data provide further evidence that in invasive breast carcinomas there is a widespread deregulated expression of integrins and their accessory adhesion molecules with loss of polarization. Changes in the expression and function of cell adhesion molecules, which control growth and differentiation, may have clinical relevance in the behavior of breast cancer.

Antigens, Surface↗
PubMed1991

Automatic needle biopsy in the diagnosis of early breast cancer.

An automatic needle biopsy system, Bioptycut, has been evaluated for use in the outpatient biopsy of 107 patients with suspected operable breast cancer. Of the 107 patients, 96 proved to have malignancy. The sensitivity of the test was 65%, and the specificity 100%. Using a fine gauge needle the sensitivity was originally less than that of Trucut biopsy, but improved results were obtained with more experience.

Biopsy, Needle↗
PubMed1988

Is the ex vivo rat gastric chamber model suitable for studying the gastrotoxicity of refluxed duodenal contents? Initial results using deoxycholic acid.

Duodenogastric reflux has been implicated in the pathogenesis of gastric mucosal disease but the relative toxicities of its constituents are not known. The suitability of the ex vivo rat gastric chamber model for systematic studies of bile acid gastrotoxicity was assessed using deoxycholic acid (DCA 0.2-5.0 mmol/l). Acute challenge with 5.0 mmol/l DCA produced significant loss of gastric transmucosal potential difference (delta PD = 25.9 +/- 3.3 mV: mean +/- SEM; p less than 0.01) compared with saline challenge (1.5 +/- 0.5 mV). Significant delta PD values were produced by DCA concentrations down to 0.5 mmol/l (16.0 +/- 2.8 mV). Challenge with 5.0 mmol/l DCA also caused significant increases in chamber fluid concentrations of nucleic acid (2.8 +/- 0.3 micrograms/ml; p less than 0.05) and acid phosphatase (130 +/- 23.4 microU/ml; p less than 0.01). This study demonstrates DCA gastrotoxicity at concentrations comparable to human intragastric total bile acid concentrations and the suitability of this model for studying the toxic components of refluxed duodenal contents.

Animals↗