Prostate-specific antigen found in type I breast cyst fluids is a secretory product of the apocrine cells lining breast gross cysts

Prostate-specific antigen (PSA), a serine protease thought to be exclusively produced by the prostate epithelial cells, has been recently found in human breast tissues and fluids. PSA in breast cancer is associated with the presence of steroid-hormones and receptors, and its presence seems to be a favourable prognostic indicator. In order to clarify whether the cells lining breast cysts may represent the source of PSA found in human breast cyst fluid, we performed an ultrastructural immunolocalization of PSA in the cells surrounding Type I breast cysts, obtained from breast cyst fluids of women affected by breast gross cystic disease, the most commonly occurring benign breast lesions associated with increased cancer risk. These apocrine cells show morphological features typical of actively synthesizing and secreting cells, and a PSA labelling distributed on free ribosomes, RER cisternae, and secretory granules, indicating that the metabolically active apocrine cells lining the Type I cysts are responsible for the production and secretion of PSA in Type I breast cyst fluids. The synthesis and intracystic accumulation of this serine protease in biosynthetically active apocrine Type I cysts can play an important role in the natural history of breast gross cystic disease as well as in the mechanism of cyst evolution.

The kidney during hibernation and arousal from hibernation. A natural model of organ preservation during cold ischaemia and reperfusion

BACKGROUND

During hibernation the kidney is in a hypothermic condition where renal blood flow is minimal and urine production is much reduced. Periodical arousal from hibernation is associated with kidney reperfusion at increasing body temperature, and restored urine production rate.

METHODS

To assess the degree of structural preservation during such extreme conditions, the kidney cortex was investigated by means of electron microscopy in the dormouse Muscardinus avellanarius during winter hibernation, arousal from hibernation and the summer active period.

RESULTS

Results show that the fine structure of the kidney cortex is well preserved during hibernation. In the renal corpuscle, a sign of slight lesion was the focal presence of oedematous endothelial cells and/or podocytes. Proximal convoluted tubule cells showed fully preserved ultrastructure and polarity, and hypertrophic apical endocytic apparatus. Structural changes were associated with increased plasma electrolytes, creatinine and urea nitrogen, and proteinuria. During the process of arousal the fine structure of the kidney cortex was also well maintained.

CONCLUSION

These results demonstrate that dormice are able to fully preserve kidney cortex structure under extreme conditions resembling e.g. severe ischaemia or hypothermic organ storage for transplantation, and reperfusion. Elucidation of the mechanisms involved in such a natural model of organ preservation could be relevant to human medicine.

Immunoreactivity, ultrastructural localization, and transcript expression of prostate-specific antigen in human neuroblastoma cell lines

Prostate-specific antigen (PSA) is considered a highly specific biochemical marker of the human prostate gland, and it currently is used for prostate cancer diagnosis and monitoring. Recently, PSA production and secretion were found in nondiseased and diseased cells, tissues, and fluids from women. In this study, we characterized the presence of PSA in two human neuroblastoma cell lines with biochemical, ultrastructural, and molecular approaches. Using reverse transcription-PCR, we identified PSA mRNA, and Western blotting revealed a substantial amount of complexed form of PSA protein, which is localized mainly in free ribosomes. Although the role of PSA in human neuroblastoma cell lines is still unknown, our study supports the hypothesis that this serine protease may be involved in controlling the growth of human brain tumor cells, adding more support to the notion that PSA is a widespread kallikrein-like protease with biological functions much more complex than recently thought.

Ultrastructural characterization and biochemical profile of human gross cystic breast disease

Human gross cystic breast disease is a benign condition affecting about 7-10% of adult women occurring with the highest incidence in the premenopausal decade. Although breast cysts do not represent a preneoplastic condition per se, several studies indicate an increased breast cancer risk in women affected by this pathology. In this report we study 115 breast cystic fluid samples obtained by needle-aspiration from women with gross cystic breast disease. The samples were analysed biochemically and the cells contained therein were observed at the electron microscope. According to their biochemical profiles, the cysts were subdivided into three types: Type I, showing a Na/K ratio < 0.5 and a typical protein content; Type II, showing a Na/K ratio >10 and a protein content quite similar to plasma; Type III, showing a Na/K ratio between 1 and 7 and an intermediate protein content. The electron microscopic examination demonstrated that Type I cystic fluid cells exhibit morphological features typical of actively synthesising and secreting cells, while the characteristics of Type II cells indicate a low metabolic activity. Type III cells have characteristics typical of both Type I and Type II cells, thereby confirming the intermediate nature of this cyst type. We hypothesise that these cyst types could represent different developmental stages of a structural evolution pathway, during which the biosynthetically active 'apocrine stage' would be the key step to cell neoplastic transformation.

Prostate-specific antigen expression in a case of intracystic carcinoma of the breast: characterization of immunoreactive protein and literature surveys

A case is presented of female breast intracystic carcinoma with prostate-specific antigen (PSA) expressed in high amounts in aspirated cystic fluid (55 micrograms/L). Tumor extract analysis revealed the presence of both estrogen and progesterone receptors (0.38 and 1.87 nmol/L, respectively) and high quantities of PSA too (19.52 micrograms/L). Chromatographic analysis of cystic fluid revealed two peaks of PSA, at the expected positions for free and bound serine protease. A major proportion of 33-kDa free from was also confirmed by Western blotting analysis. Free PSA was heat-stable at 56 degrees C and displayed no change after freezing-thawing. These findings are discussed in the context of a detailed literature survey. Our data support the contention that PSA immunoreactivity in intracystic fluid of breast carcinoma is partly the result of secretory activity by the neoplastic cells and that the steroid receptors can also modulate its expression.

Quantification of prostate-specific antigen immunoreactivity in human breast cyst fluids

The frequency of gross cystic breast disease in premenopausal women and its possible association with increased breast cancer risk emphasises the importance of investigations relating to breast cyst fluid composition. In order to contribute to a better analysis of this medium, we have measured the presence of prostate-specific antigen immuno-reactivity in sixty-four human breast cyst fluids. Data analyses show that 35% of samples presented a level of this antigen < 0.05 micrograms/L, whereas 42 out of 64 cysts show a significant increase in the mean value of metabolically active apocrine cysts when compared to flattened cysts (p < 0.01). We report the first evidence that breast epithelium of gross cysts produces, secretes, and accumulates large amounts of prostate-specific antigen, a glycoprotein produced by prostatic tissue but recently detected in breast tumours, normal tissues, and during pregnancy. The production and intracystic accumulation of this serine protease in biosynthetically active apocrine type cyst can play a feasible role in the natural history gross cystic breast disease as well as in the mechanism of cyst formation, enlargement, and transformation.

Promotion of tumour metastases and induction of angiogenesis by native HIV-1 Tat protein from BK virus/tat transgenic mice

OBJECTIVE

To characterize the T53 cell line and its clones derived from an adenocarcinoma of BK virus (BKV)/tat transgenic mice and to establish the role of native Tat in tumorigenicity, induction of metastases and angiogenesis.

DESIGN AND METHODS

Tat was quantified by flow cytometry and chloramphenicol acetyltransferase (CAT) assays. Tumorigenicity and metastatic ability of cell lines were assayed in nude mice. Production of proteases was evaluated by a plasmin chromogenic assay and gelatinase zymography. The angiogenic effect was studied in vivo with conditioned medium from tumour cell lines.

RESULTS

Tat protein was detected in tumour cell lines in amounts from 600-7000 molecules/cell. Conditioned medium from tumour cell lines was able to transactivate an LTR-CAT in HL3T1 cells, indicating release of extracellular Tat. Tumour cell lines, inoculated into nude mice induced angiogenic tumours with remarkable recruitment of host endothelial cells. Metastases were detected in lymph nodes, lungs, kidneys, and heart. Cell lines produced relevant amounts of proteases. Conditioned medium implanted in mice with matrigel induced an angiogenic response, enhanced by addition of heparin. Preincubation with an anti-Tat antibody abolished the angiogenic effect.

CONCLUSIONS

Tat from cells from BKV/tat transgenic mice promotes tumorigenesis and formation of metastases and induces angiogenic activity. Angiogenesis occurs at physiological concentrations of Tat lower than 20 ng/ml. The effects of Tat on induction of metastases and angiogenesis appear to be mediated by activation of proteases.

Lipids status in human breast cyst fluids

Benign mammary gross cystic disease is the most common breast lesion; women with apocrine changes of epithelium lining the cysts are at higher risk for developing breast cancer than the normal population. Total cholesterol, high- and low-density lipoproteins fractions, triglycerides and phospholipids, lipase activity and total lipid concentrations were measured in cyst fluids and sera from 89 women affected by gross cystic breast disease. Total cholesterol and high-density lipoprotein content were significantly (P < 0.001) greater in pooled cyst fluids than normal sera. Moreover, data analyses show a significant increase in the mean values of total lipids and lipase activity in metabolically active apocrine cysts, when compared to the flattened cysts (P < 0.001). The lipids feature of apocrine cysts could represent an altered expression of biosynthetic activity of the surrounding apocrine cell surface glycolipid and steroidogenic metabolism and may provide further knowledge about the functional stage changes of gross breast cysts.

beta-Endorphin expression in gross cystic breast disease

Opioid peptides have a variety of pathophysiologic actions, playing a novel important role in human breast cancer. The expression of beta-endorphin was studied in 84 human breast cyst fluids from gross cystic breast disease-affected patients. The concentration of beta-endorphin in pooled breast cyst fluids was over four-fold higher than in respective plasma with a significant increase in the mean value of the 'metabolically active' apocrine cysts when compared with flattened cysts (P < 0.001). The higher levels of Type I cyst suggest de novo mammary synthesis of endogenous opioid peptides and could represent an altered expression of biosynthetic activity of apocrine breast cells, providing a possible explanation on functional changes of gross cysts, on the mechanism of their formation and a perspective relationship to breast cancer risk.

Hydrogen peroxide cytotoxicity under conditions of normal or reduced catalase activity in H2O2-sensitive and -resistant Chinese hamster ovary (CHO) cell variants

H2O2-sensitive and -resistant sublines of Chinese Hamster Ovary (CHO) cells were tested for their sensitivity to the growth inhibitory effect elicited by increasing concentrations of the oxidant under conditions of normal or reduced catalase activity. Experimental results have demonstrated that, under conditions of reduced catalase activity, the cytotoxic action of H2O2 was differentially regulated in resistant and sensitive cells. Indeed, the parental cell line and cells resistant to low concentrations of H2O2 (V 250 cells) depended on catalase to a lower extent than did highly resistant cells (V 850 cells). It is interesting to note that V 250 cells had more catalase, on a per million cell basis, than V 850 cells. We conclude that acquired resistance to oxidative stress is not entirely dependent on catalase and that the contribution of catalase depends on the degree of resistance to the oxidant.

Goat immunoglobulin purification on phosphocellulose and DEAE Affi-Gel blue

We describe a method for the efficient purification of immunoglobulins G (IgG) to near homogeneity from goat serum. This was achieved by performing first an AS-40 fractionation on goat serum, followed by chromatography on phosphocellulose (P11) equilibrated in citrate buffer at pH 5.7. Peak I, eluted at V0 from P11, contained all IgG and the other serum proteins, except beta-globulins and most of the alpha-2-globulins, which are eluted in a second peak with 0.24 M K-phosphate in citrate buffer at pH 6.0. Peak I, concentrated and dialyzed in 20 mM K-phosphate buffer pH 8.0, was then applied onto a DEAE Affi-Gel Blue column equilibrated in the same buffer. Two peaks were obtained from this column: peak I, eluted at V0 contained a pure IgG fraction, while the other serum proteins were in peak II. We conclude that the P11 step, performed under the conditions we report here, is very useful to retain the alpha-2 and beta-globulins, which contaminate the IgG when only the DEAE Affi-Gel Blue purification step is used.