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Metastasis is the major cause of mortality and morbidity for patients with cancer. The high-mobility group protein 1(Y) [HMG-1(Y)] has a role in the transcription of many genes involved at different steps in the metastatic cascade and has been linked with cancer in human and animal models. This may represent a potential therapeutic target for patients. The following review summarizes and critically appraises the evidence for the role of HMG-1(Y) in metastasis., ((c) 2004 Wiley-Liss, Inc.)

Prostate-specific antigen (PSA) is a 33 kDa serine protease which is produced by many different tissues in the body and has been shown to be present in low concentrations in breast milk and in about 30% of breast cancers. The presence of PSA in breast cancers is associated with the presence of steroid-hormone receptors and may be a favourable prognostic indicator. In this study, PSA immunoreactivity was measured in breast cyst fluid obtained from women with palpable breast cysts which is the most common benign breast disease. PSA was found to be present in very low concentrations in breast cyst fluid. In an attempt to understand the possible role of PSA in the breast, the effect of PSA on growth of the hormone-dependent MCF-7 and hormone-independent MDA-MB-231 human breast cancer cell lines was studied. In addition, the effect of PSA on oestrone sulphatase activity and oestrogen 17-oxidoreductase activity in these cell lines was investigated. PSA, in low concentrations, was found to inhibit MCF-7 cell growth and to stimulate the conversion of oestradiol to the less potent oestrogen oestrone in this cell line. PSA had no effect on the MDA-MB-231 cell line. Our findings suggest that PSA may act as a negative growth regulator in hormone-dependent breast cancers.

A method for the use of a biotinylated antibody (DAKO-ER 1D5) to quantify oestrogen receptors (ER) on tumour cells by flow cytometry is described. ER quantification was determined after treatment with saponin rendering cells permeable to ER antibody. Use of dual parameter labelling was performed utilizing a FITC-conjugated antibody (NCL-5D3) directed against cytokeratin 8/18. This allowed selection of breast cancer cells of epithelial origin by gating to exclude contaminating inflammatory and stromal cells. Use of such a gating technique was seen to identify cells with a higher level of ER expression. Using QC quantum bead standards, the number of ER binding sites per cell was assessed. Results were compared with conventional ER quantification using a radio-ligand binding assay. A high degree of correlation was found between the two methods. The flow cytometric method for ER quantification described is simple, rapid, and reproducible. The assay may be of particular value in measuring ER on urgent clinical samples. Advantages of this assay over the radio-ligand binding assay include reduction in use of radio-labelled iodine compounds, a decrease in analysis time, and reduced cost and quantity of material needed for assay.

Women with breast cysts lined by apocrine epithelium (intracystic Na/K < 3) may have a higher risk of developing breast cancer than those whose breast cysts are lined by "flattened" epithelium (intracystic Na/K < 3). In this study, the concentrations of the cytokines, oncostatin M (OSM), interleukin 2 (IL-2), interleukin 6 (IL-6) and interleukin 8 (IL-8) were measured in breast cyst fluid, OSM, IL-2 and IL-6 having been shown to have growth-inhibitory actions on tumour cells. All cytokines were measured by "sandwich" enzyme immunoassays. IL-2 was not detectable in breast cyst fluid. OSM, IL-6 and IL-8 concentrations were significantly higher in the high-electrolyte-ratio group. Although significant positive correlations were found between OSM and IL-6, OSM and IL-8, OSM and Na/K, IL-6 and IL-8, IL-6 and Na/K and IL-8 and Na/K when all samples were analysed together, analysis of the correlations between these analytes in each subgroup separately suggests that the control of production of these cytokines or the mechanism of entry into cyst fluid is likely to be different for the 2 cyst types. The significantly higher intracystic concentrations of OSM and IL-6 in the high-electrolyte-ratio group may partly explain the lower risk of breast cancer in this group of women.

A method for the purification, conjugation, and use of EGF-R antibody to quantify EGF receptors on tumour cells by flow cytometry is described. The quantification of both internal and external EGF receptors was determined by treatment with saponin, rendering the cells permeable to the EGF-R antibody. Using QCS bead standards, the number of EGF-R binding sites per cell was assessed. Results were compared with conventional EGF-R quantification using a radio-ligand binding assay. A high degree of correlation was found between the two methods. The flow cytometric method for EGF-R quantification described is simple, rapid, and reproducible. The assay may be of particular value in measuring EGF-R on urgent clinical samples or those that are too small (such as breast aspirates) for measurement by the radio-ligand binding assay. Advantages of this assay over the radio-ligand binding assay include reduction in use of radio-labelled iodine compounds, a decrease in analysis time, and reduced cost and quantity of material needed for assay. In addition, flow cytometry offers the possibility of selecting cell phenotypes by gating as well as live/dead cells by using multi-parameter flow cytometry.

There are 2 main groups of breast cysts characterized by their intracystic sodium-to-potassium ratios. Women who have intracystic Na/K < 3 may have a higher risk of developing breast cancer than those who have intracystic Na/K > 3. The cell adhesion molecule, ICAM-I, has been shown to be inducible by interleukin-I (IL-I). Furthermore, ICAM-I may be involved in the progression of metastasis in certain malignancies. The aim of this study was to measure intracystic soluble ICAM-I (sICAM-I) and IL-I alpha/beta levels and to assess the relationships between these substances. Wide-ranging concentrations of sICAM-I, IL-I alpha and IL-I beta were found in breast-cyst fluid. The high-electrolyte-ratio group had intracystic levels of sICAM-I and IL-I beta which were significantly higher than those of the low-electrolyte-ratio group. No significant difference was found between IL-I alpha concentrations in the 2 groups of breast cysts. Strong positive correlations were found between sICAM-I and IL-I alpha, sICAM-I and IL-I beta, and IL-I alpha and IL-I beta. The significance of the higher concentrations of sICAM-I in the high-electrolyte-ratio group remains to be determined, but the results of this study suggest that sICAM-I levels in the high-electrolyte-ratio group may be regulated in part by IL-I alpha and IL-I beta.

Amplification of the int-2 oncogene was measured in a series of breast tumours and related to amplification of the c-myc and c-erbB-2 oncogenes, histopathological features and relapse-free and overall survival. int-2 was amplified in 11%, c-myc in 20% and c-erbB-2 in 27% of the tumours assessed. int-2 amplification was associated with large tumour size (p < 0.05) and reduced relapse-free (p < 0.05) and overall (p < 0.0005) survival. c-myc amplification was associated with poor tumour differentiation (p < 0.05) but had no association with prognosis. c-erbB-2 amplification was associated with low levels of expression of oestrogen receptor mRNA (p < 0.05), poor tumour differentiation (p < 0.05) and shortened relapse-free (p < 0.0001) and overall survival (p < 0.0001). This is the first report of an association between amplification of the int-2 oncogene in breast tumours and a significantly increased risk of death from breast cancer, and suggests that int-2 may be useful for identifying breast-cancer patients having a poor prognosis.