Expression of syndecan-1 in histologically normal breast tissue from postmenopausal women with breast cancer according to mammographic density

OBJECTIVE

To analyze the expression of Syndecan-1 in dense and non-dense human breast tissue.

METHODS

Specimens of histologically normal tissue were obtained from postmenopausal women undergoing surgery for breast cancer. Each tissue block was subject to radiological examination and pair-wise samples of dense and non-dense tissue were collected. Semi-quantitative assessment of immunohistochemical staining intensity for Syndecan-1 and estrogen receptor subtypes was performed.

RESULTS

The expression of Syndecan-1 in all tissue compartments was significantly higher in dense than in non-dense specimens. The strongest staining was recorded in stromal tissue. There was a strong correlation between epithelial estrogen receptor alpha and stromal cell Syndecan-1 expression in dense tissue (rs = 0.7; p = 0.02). This association was absent in non-dense tissue.

CONCLUSION

An increase of Syndecan-1 in all tissue compartments and a redistribution from epithelium to stroma may be a characteristic feature for dense breast tissue.

The role of cathepsin D and PAI-1 in primary invasive breast cancer as prognosticators and predictors of treatment benefit with adjuvant tamoxifen

In the last few years there has been an increased interest in treatment predictive factors in breast cancer patients. The aim of the study was to analyse the role of cathepsin D and plasminogen activator inhibitor-1 (PAI-1) expression as independent prognosticators and to assess their predictive value with respect to tamoxifen treatment. This study comprises 1851 patients with primary breast cancer diagnosed during 1988-1992. Their median age was 62 years (range: 24-91). The end-point was distant disease recurrence-free interval. Adjuvant treatment with tamoxifen was given to 1136 patients (61%). The median follow-up time was 59 months (range: 39-88). Cathepsin D content was shown to be a significant independent prognosticator in multivariate Cox analysis (P=0.02). The optimal cut-off level was 10 fmol/mg protein, other cut-off levels did not improve the results. The level of cathepsin D also appeared to predict the benefit of tamoxifen among oestrogen receptor (ER)-positive patients although this result did not reach statistical significance (P=0.09). In a multivariate Cox analysis including 497 patients PAI-1 content was shown to be a significant independent prognosticator (P=0.003) but did not appear to predict the benefit of tamoxifen treatment. The optimal cut-off level appeared to be 3 ng/mg protein, which was close to the median value 2.5 ng/mg (range: 0-51). We conclude that cathepsin D is a significant independent prognosticator and may possibly also predict the benefit of tamoxifen amongst ER-positive patients. PAI-1 was also found to be a strong independent prognosticator but no treatment interaction with adjuvant tamoxifen was found.

Transforming growth factor alpha in human mammary carcinomas and their metastases

A binding competition assay was used to measure the content of transforming growth factor alpha in human mammary carcinomas and their metastases. Thirty one percent of the primary and 50 percent of the metastases expressed the transforming growth factor alpha with values ranging between 1.6 to 278 EGF equivalent ng/mg tumour extract protein. There was no correlation between the transforming growth factor alpha content and the estrogen receptor value.

Identification of transforming growth factor alpha in human primary breast carcinomas

Primary human mammary carcinomas were found to contain an acid stable polypeptide which bound to the receptor for epidermal growth factor (EGF). This polypeptide which was antigenetically different from EGF and thus identified as Tumor Growth Factor (TGF) alpha, could be identified in 25% of the tumors. Among these tumors 40% contained measurable levels of the EGF receptor. Thus these tumors exhibit the molecular prerequisite for autocrine growth stimulation.

Prognostic significance of the receptor for epidermal growth factor in human mammary carcinomas

125I-EGF binding technique was used to demonstrate high affinity receptor binding for epidermal growth factor (EGF-R) in 72 human mammary carcinomas. 27% of the tumors were EGF-R positive and the presence of this receptor was correlated with receptor levels for estradiol, DNA-pattern, proliferative index, thymidine kinase, tumor size, number of lymph node metastases and 6-year relapse probability. Our results confirm previous reports of an inverse relation between the cellular content of EGF-R and ER. In addition, we could associate EGF-R positivity with an aneuploid DNA-pattern and an increased growth rate, as measured by proliferative index. No correlation was found between EGF-R positivity in the primary tumor and presence of axillary lymph node metastasis at the time of operation. The 6-year relapse rate was somewhat higher for patients whose primary tumors were EGF-R positive. Moreover patients who had lymph node metastases at the time of operation and EGF-R positive tumors experienced a significantly lower 6-year disease free survival rate as compared to those who were node negative and had receptor negative tumors. It remains to be shown whether EGF-R alone can be used as an independent prognostic factor.

Detection of TdT in AML blasts by immunological and biochemical techniques

The cellular level of terminal deoxynucleotidyl transferase (TdT) was measured in blasts from patients with AML. Parallel determinations were made using an immunoassay and polymerizing reaction. There was a good correlation between the two techniques (r = 0.92) and detectable levels of the enzyme was found in approximately 50% of the cases. The TdT levels found in AML blasts were 1/10 - 1/100 of that reported for cells of lymphoid origin.

Enzyme markers in acute myeloid leukaemia

The levels of TdT, AdA, 5'-N, 20 alpha-SDH and TK1 were analyzed in different FAB subgroups of AML. AdA, 5'-N, 20 alpha-SDH and TK1 showed large variations both within and between the different subgroups. It therefore seems unlikely that measurements of these enzymes will be able to aid morphological subclassification of AML. Neither could analysis of these enzymes give prognostic information. TdT was detectable in 46% of AML but the levels were only 1/10-1/100 of those found in ALL. The enzyme was detected in leukaemic granulocytopoietic cells while leukaemic cells of monocytic origin were negative in all but 1 case. In addition, increased TdT activity was positively correlated to the length of survival.

Glucocorticoid receptor concentrations and terminal transferase activity as indicators of prognosis in acute non-lymphocytic leukaemia

Activity of terminal deoxynucleotidyl transferase (TdT), adenosine deaminase, and 5'nucleotidase and the cellular concentration of glucocorticoid (dexamethasone) receptor were determined in 25 patients with acute non-lymphocytic leukaemia. All patients were treated according to a common protocol. Increased activity of TdT (greater than 0.1 unit/microgram DNA) was found in 11 patients. This group of patients was shown to have higher remission and survival rates (p = 0.06) compared with patients with low activity of TdT. The glucocorticoid receptor concentration of the leukaemic blast cells ranged from 0 to 0.94 fmol/microgram DNA. Thirteen patients had blast cells with a glucocorticoid receptor concentration over 0.22 fmol/microgram DNA. These patients had significantly increased remission and survival rates (p = 0.006) compared with those with a low receptor concentration. This finding cannot be explained by a difference in sensitivity to glucocorticoids since these were not used as therapeutic agents. Adenosine deaminase and 5'nucleotidase activities both varied within two orders of magnitude. No correlation could be found between activities of these enzymes and remission or survival rate. These results show that measurements of TdT activity and the glucocorticoid receptor concentration yield valuable prognostic information in acute non-lymphocytic leukaemia.

2'-Deoxy-2'-azidocytidine, a new inhibitor of DNA replication in mammalian cells

Cell growth is reversibly inhibited by the nucleoside analogue, 2'-deoxy-2'-azidocytidine and the inhibition is a result of interference with DNA replication. The 5'-diphosphate of the analogue was earlier shown to specifically inactivate the enzyme ribonucleotide reductase in vitro. However, measurements of the pools of deoxyribonucleoside triphosphates in cells incubated in azidocytidine showed only minor changes which appeared to result from and not to be the cause of the inhibition of DNA replication. The DNA synthesized in polyoma-infected cells after incubation in azidocytidine showed a sedimentation pattern quite different from that seen after inhibition of DNA synthesis with arabinosyl cytosine or hydroxyurea. Experiments with nuclei isolated from azidocytidine-inhibited, polyoma-infected cells indicated (a) that the number of replicating molecules is decreased during the inhibition and (b) that upon incubation of the nuclei there is a rapid synthesis of DNA occurring in a new class of DNA molecules which are at a very early state of replication. Neither the 5'-triphosphate of azidocytidine nor the nucleoside itself inhibit DNA synthesis in vitro in isolated nuclei from polyoma-infected cells and at present the nature of the DNA-synthesis-inhibiting compound acting in the cells after addition of azidocytidine is unknown. Taken together the results suggest that azidocytidine inhibits DNA synthesis at an early stage, possible by blocking the initiation of DNA synthesis at the origin or by interfering with the elongation of newly initiated DNA molecules.