Acidic and basic fibroblast growth factors in human breast tissue

Previously we have reported changes in fibroblast growth factors (FGF) in conditioned medium (CM) derived from rat mammary tumours undergoing remission. We have used a similar approach to assay for the presence of FGFs in human breast tissue and cell lines. The majority of cancer tissues (35/50), benign tissues (8/9) and all cancer adjacent normal tissues (20/20) released heat labile, NR6 transforming activity which coeluted from heparin with acidic FGF (aFGF) at 0.9-1.1 M NaCl and was neutralised by antibodies to aFGF. The conclusion that the majority of breast cancers contain active aFGF was supported by immunoblotting. The CM of a minority (15/50) of cancers and one benign tissue had highly transforming activity for NR6 cells, and was mitogenic for a breast cancer cell line, was heat labile, and strongly heparin binding, eluting at 1.5-2.0 M salt. It was not immunoreactive with antibodies to aFGF, basic FGF (bFGF) or Kaposi's FGF (kFGF) and its activity was reduced by the presence of aFGF, suggesting competition for the same receptor. Very little aFGF was observed in the CM of these tumours, and neither aFGF nor other FGF activity was detected in CM of breast cell lines.     

Electron density of normal and pathological breast tissues using a Compton scattering technique

Compton (incoherently) scattered photons which are directly proportional to the electron density of the scatterer, have been employed in characterising human breast tissues. Gamma ray photons scattered incoherently from normal and pathological breast tissue samples of nine breast cancer patients were measured using a high purity germanium detector and an americium (Am-241) source. The breast tissue samples were obtained from female patients undergoing mastectomy. The samples were examined in freeze dried form and the results were corrected for the reduction in the water content of each tissue type by use of the Mixture Rule. This study is aimed at providing electron density information in support of the introduction of new tissue substitute materials for mammography phantoms.     

Enteral nutrition modifies gut-associated lymphoid tissue in rat regardless of the molecular form of nitrogen supply

OBJECTIVES: It is not known whether the results of randomized trials comparing coronary artery bypass grafting to percutaneous transluminal coronary angioplasty for initial revascularization apply to repeat revascularization in patients with prior bypass grafts. We studied the differences between the patients with prior bypass grafts referred for surgery or angioplasty to identify the clinical and angiographic characteristics that correlated best with either choice and to find clues that might aid in selecting one treatment over the other. METHODS: Between 1992 and 1994, 870 patients underwent first isolated reoperation and 793 patients underwent first balloon angioplasty after a previous operation. A jeopardy score (0 to 8 points) was derived for each patient on the basis of the relative size of the ischemic territory. Clinical and angiographic data were analyzed for association with the revascularization strategy. RESULTS: The following characteristics were more prevalent in the reoperation group: male sex, diabetes, hypertension, valvular disease, normocholesterolemia, and severe left ventricular systolic dysfunction; fewer functioning venous and arterial grafts; and a higher jeopardy score (p < 0.01 for all) than in the angioplasty group. A higher jeopardy score, diabetes, and a lower number of functioning arterial or venous grafts were strong, independent predictors of referral for reoperation (p < 0.01 for all). In hospital death and Q-wave infarction (p < 0.01 for both) were more frequent in the reoperation group. CONCLUSIONS: Reoperation was the revascularization procedure of choice when larger regions of myocardium were in jeopardy. Angioplasty was more frequently chosen in the presence of a patent arterial graft to the left anterior descending coronary artery or multiple functioning bypass grafts. Reoperation was associated with a higher risk of in-hospital complications than angioplasty.     

Protein expression profiles in human breast ductal carcinoma and histologically normal tissue

Reference two-dimensional (2-D) gels are presented for human breast ductal carcinoma and histologically normal tissue. Whole biopsy fragments were analyzed, including epithelial and nonepithelial components. Thirty-five spots have been assigned by gel matching to the human liver SWISS-2DPAGE reference map and/or to the human primary keratinocyte IPG map from the Danish Center for Human Genome. N-terminal microsequencing was applied to confirm randomly chosen matching assignments and to identify six new spots. Protein expression profiles in ductal carcinoma and in normal breast tissue appeared to be similar, except for a pattern consisting of 32 spots, which were highly expressed in all carcinoma specimens, and less intense and occasionally undetectable in normal tissue. This difference was statistically significant. Assignment has been obtained for several spots, namely GRP94, GRP78, GRP75, mitochondrial HSP60, calreticulin, protein disulfide isomerase, peptidyl-prolyl cis-trans isomerase, collagen-binding protein 2, fructose bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, thioredoxin, cytochrome c oxidase VA subunit, tubulin beta isoform and macrophage migration inhibitory factor (MIF). The cancer- and tissue-specificity of the described pattern was assessed by matching to the Swiss-2DPAGE human liver, hepatoma, lymphoma, erythroleukemia reference maps. The pattern of 32 spots was found to be indicative of epithelial neoplasia.     

Alternative splicing of CYP2D mRNA in human breast tissue

Cerebrovascular arteriovenous malformations (AVMs) display abnormal vascular development and dysautoregulation of blood flow. Genetic mechanisms that contribute to the pathogenesis and phenotype of cerebral AVMs are unknown. As a first step in understanding the pathophysiology of AVMs, the authors investigated the hypothesis that endothelial dysfunction-specifically, deregulation of endothelin-1 (ET-1) secretion-contributes to the abnormal vascular phenotype and the lack of hemodynamic autoregulation elaborated by these lesions. Endothelin-1 peptide and preproendothelin-1 (ppET1) messenger RNA were not detected in the intranidal vasculature of all 17 patients with AVMs studied, but were prominently expressed in human control subjects with normal cerebrovasculature (p < 0.01). Although AVM vasculature lacked ET-1, its expression was prominent in vasculature distant from these lesions, suggesting local repression of the ppET-1 gene. Local repression of ET-1 was specific to AVMs; ET-1 in vascular malformations of patients with Sturge-Weber disease was actually elevated compared to normal controls (p < 0.01). Repression of the ppET-1 gene was an intrinsic phenotype of AVM endothelial cells and was not due to factors in the AVM microenvironment. The authors also showed that ETA receptor expression was low in AVM vasculature compared to normal controls. Together, these results demonstrate that the ppET-1 gene is locally repressed in AVM lesions and suggest a role for abnormal ppET-1 gene regulation in the pathogenesis and clinical sequelae of cerebral AVMs.     

Tamoxifen down-regulates CD36 messenger RNA levels in normal and neoplastic human breast tissues

Tamoxifen (TAM) exerts a long-term suppressive effect on human breast cancer cell proliferation. To determine whether the effects of TAM are mediated by specific gene activation or repression, normal and tumoral human breast tissues obtained before and during TAM treatment were analyzed by differential display technique. Total RNA for differential display analysis was obtained from breast tissues from two women with the diagnosis of estrogen receptor-positive stage II (T2N1M0) infiltrating ductal carcinoma, made by incisional biopsy, followed by modified radical mastectomy performed after a 30-day treatment with TAM (20 mg/day). One 202-bp cDNA band, AP5-1, was present in normal and tumoral biopsy samples, but was absent in breast tissue obtained during TAM treatment, and was confirmed by Northern hybridization, which showed a 2.7-kb band in both patients. The differentially expressed cDNA fragment showed 99% homology to Homo sapiens CD36 gene, a glycoprotein that acts as a receptor for the extracellular matrix proteins thrombospondin-1, collagen types I and IV, and oxidized low-density lipoprotein. These results indicate that the down-regulation of CD36 induced by TAM might represent alternative or additional mechanisms of action of this drug affecting the functions of thrombospondin-1, which is involved in hematogenous tumor spread, invasion and angiogenesis, and oxidized low-density lipoprotein, playing a role in inhibition of arteriosclerosis. The multiple functions affected by the down-regulation of CD36 by TAM warrant the need for additional studies.     

Identification of human acetyl-CoA carboxylase isozymes in tissue and in breast cancer cells

1. In the rat, acetyl-CoA carboxylase (ACC), a rate-limiting enzyme in fatty acid metabolism, exists as at least two different isozymes (M(r) 265,000 and 280,000) that display distinct tissue-specific distribution and regulation. 2. Based on the study of human tissue and human-derived breast cancer cell lines by enzyme isolation and protein blotting techniques, we have now identified two human isoforms of M(r) 265,000 (HACC 265) and 275,000 (HACC 275), each of which is homologous to one of the rat isozymes. 3. Human breast carcinoma cell lines show variable expression of these two isoforms, mirrored in the estimation of ACC acetyl-CoA kinetics.     

Angiogenic potential of malignant and non-malignant human breast tissues in an in vivo angiogenesis model

Tumors need to acquire an angiogenic phenotype for outgrowth and metastasis formation. Limited information on the angiogenic potential of specific tissues, especially human breast tissues is available. Here we describe an in vivo model, using the dorsal skin fold chamber in immunodeficient nude mice, where various tissues of human breast origin were xenografted and evaluated for their angiogenesis-inducing potential. We found that angiogenesis was abundantly induced by all breast carcinoma tissue samples. Similar angiogenesis was induced by tissue samples from breasts with hyperplasia and apocrine metaplasia. Histologically normal tissues adjacent to the tumor induced angiogenesis in 66% of the cases. Angiogenesis was not induced by control tissues from normal healthy breasts, obtained after cosmetic breast reduction. Angiogenesis induction parallelled VEGF production by the tumor cells. The tissue induced neovascularization, found both around and in the human tissue, was functional since a tail vein injection of albumin-FITC revealed positive tumor microcirculation within 5 min, while the tumor tissue still consisted of vital human epithelial cells after 14 days.