Distribution and prognostic value of the fibroblast growth factor-2 low-affinity binding sites in human breast cancer.

We performed a competitive binding study with 125I-labelled FGF (fibroblast growth factor)-2 and unlabelled FGF-2 in an unselected series of two hundred and thirty human primary breast cancers. One hundred and ninety-two breast cancer biopsies possessed FGF-2 low-affinity binding sites (FGF-2 LABS). The median dissociation constant was 2.4 nM (range, 1.03-18) and the median concentration of membrane protein was 6187.5 fmol/mg (range, 831-90,000). FGF-2 LABS concentrations were positively correlated to the progesterone receptor level. Cox univariate analyses showed that the FGF-2 LABS (> or = upper quartile) was associated to a longer overall survival (p = 0.05; RR = 0.042); node involvement, estrogen receptor progesterone receptor and histoprognostic grading were also prognostic. In Cox multivariate analyses, only the progesterone receptor, estrogen receptor, node involvement and FGF-2 LABS were prognostic factors; the FGF-2 LABS were associated with a longer overall survival (p = 0.033; RR = 0.068). The present study showed that FGF-2 LABS have only a limited role as a prognostic factor in breast cancer.

Prognostic value of circulating soluble E-selectin concentrations in node-negative breast cancer patients.

Several studies have suggested that endothelial cells participate in tumor development. Soluble E-selectin (sE-selectin) is specifically released by activated endothelial cells, and its serum concentration can be considered a marker of endothelial activation. In this study, we assessed the prognostic value of sE-selectin concentrations in node-negative breast cancer patients. Serum sE-selectin concentrations were measured by an ELISA method prior to surgery in 456 node-negative breast cancer patients. We analyzed also tumor size (TS), histoprognostic grading, and steroid hormone receptor status. The mean sE-selectin concentration was 24.9 +/- 15.0 ng/ml. The sE-selectin concentrations were mildly correlated with the TS but not with the other factors. For prognostic analyses, the median follow-up duration was 7.5 years. The cutoff sE-selectin concentration used was 40 ng/ml. In overall survival studies, univariate analyses demonstrated a prognostic value of sE-selectin, TS, and histoprognostic grading, and multivariate analyses demonstrated a prognostic value of sE-selectin and TS. For disease-free survival, univariate and multivariate analyses demonstrated a prognostic value of sE-selectin and TS. sE-selectin concentration is an easily measurable and strong prognostic factor in node-negative breast cancer patients. These results provide further evidence for the role of adhesion molecules expression by endothelial cells in tumor progression.

Basic fibroblast growth factor receptors and their prognostic value in human breast cancer.

We performed a saturation binding study with 125I-labeled FGF (fibroblast growth factor)-2 in a nonselected series of 250 human primary breast cancers. Two hundred twenty-five breast cancer biopsies possessed bFGFR (basic FGF receptor). The median dissociation constant was 0.35 nM (range, 0.014-1.9), and the median concentration was 1126 fmol/mg protein (range, 49-7328). FGFR-1 was localized, using a specific monoclonal antibody, in cancerous cells and in epithelial cells in normal breast or in benign tumors. In all of the tissues studied, light stromal cell staining was also observed. Thus, the localization of FGFR-1 in carcinoma cells supports the hypothesis that an important part of FGF-2 binding reflects binding to FGFR-1. bFGFR concentrations were positively correlated to estrogen receptor and progesterone receptor levels. Cox univariate analyses showed that the bFGFR (> or = upper quartile) was associated to longer relapse-free survival [P = 0.004; RR (risk ratio), 0.46] and overall survival (P = 0.001; RR, 0.35); age, estrogen receptor levels, progesterone receptor levels, node involvement, tumor diameter, and histoprognostic grading were prognostic, also. In Cox multivariate analyses, only the bFGFR, age, node involvement, and histoprognostic grading were prognostic factors; the bFGFR was associated with longer relapse-free survival (P = 0.03; RR, 0.4) and overall survival (P = 0.009; RR, 0.3). The present study confirms that FGF could be an important regulator of human breast cancer growth and that patients with a high level of bFGFR had a better prognosis.

The relationship between concentrations of circulating soluble E-selectin and clinical, pathological, and biological features in patients with breast cancer.

Increasing evidence suggests that E-selectin contributes to tumor growth and metastasis. E-selectin may increase tumoral angiogenesis and the adhesion of tumoral cells to endothelial cells at distant sites. The aim of this study was to assess the relationship between concentrations of circulating soluble E-selectin (sE-selectin) and clinical, pathological, and biological features in patients with breast cancer (BC). Concentrations of sE-selectin were analyzed by an ELISA method in sera from 113 patients with metastatic BC, 30 patients with primary inflammatory BC, 105 patients with primary noninflammatory BC, and 42 healthy controls. These concentrations were analyzed in terms of the clinical and pathological features of the tumors as well as in terms of the concentrations of serum inflammatory parameters (erythrocyte sedimentation rate, C reactive protein, interleukin 1 beta, and tumor necrosis factor alpha), the response to chemotherapy or hormone therapy, and the survival duration. Tumoral angiogenesis was also assessed in 68 patients with primary noninflammatory BC who had had primary surgery. The mean concentration of sE-selectin in the metastatic BC group was significantly higher than the mean concentration found in the healthy control group (33.5 versus 21.8 ng/ml; P < 0.01). In metastatic BC, the mean concentration of sE-selectin was significantly higher in patients with liver metastasis than in patients without liver metastasis (55.3 versus 26.0 ng/ml; P < 10(-5). The univariate analysis showed that high concentrations of sE-selectin were associated with reduced overall survival (P < 0.05), but this probably reflected the association between high concentrations of sE-selectin and liver metastasis. In patients with primary noninflammatory BC, a negative correlation was found between sE-selectin concentrations and the tumoral microvessel count (r = -0.47; P = 10(-4). In patients with primary inflammatory or noninflammatory BC, no correlation was found between concentrations of sE-selectin and tumor size, lymph node involvement, response to chemotherapy or hormone therapy, and survival. No correlation was found between the concentrations of sE-selectin and serum inflammatory parameters in any of the patient groups. This study suggests that in patients with metastatic BC, levels of sE-selectin are higher in the presence of liver metastasis. In patients with primary BC, high concentrations seem to be associated with reduced tumoral angiogenesis. Although several studies have previously demonstrated that the expression of cell surface E-selectin enhances the metastatic process, the shedding of sE-selectin in circulation may be considered a mechanism of inhibition of tumor progression.

Plasma insulin-like growth factor-1 (IGF-1) concentrations in human breast cancer.

Insulin-like growth factor-1 (IGF-1) is capable of stimulating breast cancer cell growth in vitro and the presence of IGF-1 receptors has been demonstrated in primary breast cancers. We determined plasma IGF-1 in a primary breast cancer population and in a control population. Radioimmunoassays were performed either directly on plasma, IGF-1 (NE), or after an acid-ethanol extraction of the plasma, IGF-1 (E). We demonstrated an inverse correlation between age and IGF-1: for this reason, only results obtained in females of the same age range (> 35 years) were compared. Median concentrations of IGF-1 were significantly higher in primary breast cancers [IGF-1 (E) = 152 ng/ml, IGF-1 (NE) = 26 ng/ml, n = 44] than in controls [IGF-1 (E) = 115 ng/ml, IGF-1 (NE) = 20 ng/ml, n = 92]. To our knowledge such a growth factor increase has never been described in breast cancer. We conclude that IGF-1 could be an important factor involved in the development of breast cancer and that treatment reducing IGF-1 levels could be beneficial for patients.

Basic fibroblast growth factor (bFGF): mitogenic activity and binding sites in human breast cancer.

We investigated binding characteristics of basic fibroblast growth factor (bFGF) on membranes prepared from 4 human breast cancer cell lines and 38 primary BC biopsies. Competitive binding experiments were performed and analyzed using the "Ligand" program. Furthermore bFGF mitogenic activity was measured by [3H]thymidine incorporation into DNA from breast cancer cell lines. The presence of high-affinity binding sites was demonstrated in each cell type (MCF-7: Kd = 0.60 nM; T-47D: Kd = 0.55 nM; BT-20: Kd = 0.77 nM; MDA-MB-231: Kd = 0.34 nM). The presence of these high-affinity binding sites was confirmed with saturation experiments. A second class of low-affinity binding sites was detected in the 2 hormone-independent cells (BT-20: Kd = 2.9 nM; MDA-MB-231: Kd = 2.7 nM). bFGF stimulated the proliferation of MCF-7, T-47D, BT-20 but not MDA-MB-231 cell lines. With competition experiments, binding sites were detectable in 36/38 breast cancers; high-affinity binding sites (Kd less than 1 nM) were present in 19/36 cases and low-affinity binding sites (Kd greater than 2 nM) were present in 29/36 cases (the two classes of binding sites were present in 12 breast cancers). No relation between bFGF binding sites and node involvement, histologic type or grading of the tumor was evidenced. There were negative correlations (Spearman test) between total bFGF binding sites and estradiol receptor (P = 0.05) or progesterone receptor (P = 0.009). The demonstration of (1) bFGF specific binding sites in breast cancer membranes, and (2) bFGF growth stimulation of some breast cancer cell lines indicates that this factor may be involved directly in the growth of some breast cancers.

Demonstration of basic fibroblast growth factor high and low affinity binding sites in human breast cancer cell lines.

The binding characteristics of basic fibroblast growth factor (bFGF) to membranes prepared from four human breast cancer cell lines (BT-20; MCF-7; MDA-MB-231; T-47D) have been investigated. Scatchard analyses of competition experiments indicate one class of specific binding sites in MCF-7 and T-47D cells, and two classes of specific binding sites in BT-20 and MDA-MB-231 cells. The presence of high affinity sites was demonstrated in each cell type. These results have been confirmed using saturation experiments. Chemical crosslinking of labeled bFGF in breast cancer cell lines followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed one specific complex with a relative molecular mass of about 85,000. A second class of lower affinity binding sites was detected only in the two hormone-independent cell lines. bFGF stimulation of proliferation has also been demonstrated in MCF-7, T-47D, and BT-20, but not in MDA-MB-231, which has a high proliferation activity without the addition of growth factors. These suggest that the presence of bFGF specific binding sites in human breast cancer cell membranes is a necessary but not sufficient condition for exogenous bFGF growth stimulation of these cells; they also suggest that FGF plays a role in breast cancer.

Effect of the long-acting somatostatin analogue SMS 201-995 (Sandostatin) in advanced breast cancer.

Sixteen post-menopausal patients with advanced breast cancer were treated with a long acting somatostatin analogue, SMS 201-995 (Sandostatin): 0.1 mg bid sub-cutaneously. The dose was chosen on the basis of efficiency in acromegaly treatment. SMS 201-995 activity was evaluated assaying Insulin Growth Factor 1 (IGF1) plasma concentration. A merely partial IGF1 decrease was noted. To be evaluable for response, patients had to be treated for at least 30 days. Among the 14 evaluable patients, we observed no response to SMS 201-995. However, we noted tumor stabilization in 3 patients after a 90 days treatment period. Side-effects were very mild. This first report on SMS 201-995 treatment of breast cancer suggests that further studies evaluating the effect of other modes of administration or drug association should be warranted.

Presence and characterization of insulin-like growth factor 1 receptors in human benign breast disease.

Insulin-like growth factor 1 binding sites were characterized in human benign breast disease. We demonstrated the presence of one high affinity binding site. Chemical cross-linking of [125I]IGF1 to benign breast disease membranes in reducing condition and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed one band with an apparent Mr of 130,000. The specificity of the binding was studied: IGF 2 was a good competitor whereas insulin competed for binding with a potency lower than 1/100 that of IGF1. This IGF1 binding corresponded to the previously described type I IGF receptor (IGF1-R). IGF1-R was assayed in 35 cases of benign breast disease and two samples of normal breast tissue. Forty-three per cent of the lesions were IGF1-R positive. The mean geometric level of specific binding was 1.98% in the whole population, it was significantly lower in adenofibromas (1.55%) than in epithelial hyperplasia (2.5%); it was 2% in dystrophic disease. IGF1-R was undetectable in normal tissue. Considering our previous results showing that almost all the breast cancers contained IGF1-R, these data suggest that the increase in IGF1-R could be a marker of malignant tumor development.