Histochemical studies with an estrogen receptor-related protein in human breast tumors.

The histochemical characteristics of a Mr 29,000 phosphoprotein related to estradiol receptor are described in a large series of human breast tumors. The antigen was detected with a monoclonal antibody (D5) raised against partially purified human myometrial estradiol receptor. An indirect immunoperoxidase method was used with methacarn-fixed, wax-embedded sections. Quantitation of staining and its reproducibility are described. Results with trucut biopsies agree with those obtained with larger tumor sections. Normal breast is infrequently positive. Histochemical staining is higher in invasive carcinoma than in normal breast with ductal carcinoma in situ adjacent to infiltrating tumors exhibiting intermediate values. Furthermore, most in situ carcinomas have a heterogeneous staining pattern. About 20% of invasive tumors also exhibit heterogeneity. No simple correlation is seen between staining and histological grade. There are more low-staining tumors in young (less than 50 yr old) patients than in older women. Staining correlates with levels of cytosol estradiol receptor but not cytosol progesterone receptor. However, cytosol estradiol receptor-negative, cytosol progesterone receptor-positive tumors tend to have positive Mr 29,000 phosphoprotein levels. Positive staining is associated with a higher response rate to hormone therapy (50%). None of the negative tumors responded to hormone treatment. With these patients, comparison of histochemical assay for Mr 29,000 phosphoprotein and [3H]estradiol binding assays indicated that the former was at least as good as the latter assay in predicting hormone response. About 20% of cytosol estradiol receptor-positive tumors have low Mr 29,000 phosphoprotein, and such tumors have poor response to hormone treatment.

Persistent karyomegaly caused by Penicillium nephrotoxins in the rat.

Continuous or intermittent consumption by rats of food moulded by Penicillium aurantiogriseum induced prominent and extensive histopathological changes within several weeks seen specifically at the renal cortico-medullary junction. Many cells of the P3 segment of proximal tubules contained either giant nuclei or multiple enlarged nuclei, described in this text as karyomegaly, but also included within a cytomegalic change. The changes contrasted with the tubular cell necrosis and concomitant mitosis elicited after only four days consumption of nephrotoxic mould. Unilateral nephrectomy enabled persistence of histopathological changes to be assessed directly after detailed histology at an earlier stage. After ten days consumption of food with a 100-fold excess of fungal extract containing the amphoteric nephrotoxins, the typical acute histopathology evolved, over a period of three weeks on normal diet, into the bizarre karyomegalic histopathology, implying a latent effect. Karyomegaly persisted for at least twelve months after nephrotoxin dosage ceased. P. aurantiogriseum karyomegaly was much more striking than that induced by a relatively high chronic dose of another Penicillium nephrotoxin, ochratoxin A. Although the study does not attempt to measure relative potencies, qualitatively similar ultrastructural changes (enlarged nuclei, proliferation of smooth endoplasmic reticulum and thickening of proximal tubule basement membranes) were induced by the two types of nephrotoxin. The broadly toxic ochratoxin A is the popular putative aetiological agent in the mysterious and insidious Balkan endemic nephropathy and associated urinary tract tumours. As the renal carcinogenicity of ochratoxin A in rats follows karyomegaly, the striking karyomegaly induced by P. aurantiogriseum in the proximal tubules of the kidney must be considered as a potential factor in human chronic renal disease.

Inhibition of AIDS-Kaposi's sarcoma cell induced endothelial cell invasion by TIMP-2 and a synthetic peptide from the metalloproteinase propeptide: implications for an anti-angiogenic therapy.

In the initial phases of angiogenesis, endothelial cells must degrade and cross the vessel basement membrane, as do tumor cells during invasion and metastasis formation. Various metalloproteinases have been implicated in tumor cell invasion, in particular MMP-2 (72 kDa collagenase IV, gelatinase A), which has been demonstrated to be associated with tumor metastasis formation. Supernatants from AIDS-Kaposi sarcoma (KS) cells induce normal endothelial cells to invade through a reconstituted basement membrane (Matrigel) in vitro, which correlates with the angiogenic potential of KS cells in vivo. Here we demonstrate that two specific inhibitors of MMP-2, TIMP-2 and a peptide from the MMP-2 propeptide region (peptide 74), inhibit endothelial cell invasion induced by AIDS-KS cell supernatants. Smooth muscle cells were much less sensitive to these inhibitors. These data suggest that MMP-2 activation is a key event in endothelial cell invasion, the initial phase of tumor-associated neoangiogenesis. Inhibition of this enzyme could be an effective treatment for KS and tumor-associated angiogenesis.

Variation in the use of chemotherapy in lung cancer.

Factors influencing the use of chemotherapy for the initial (6 months) treatment of lung cancer in South East England were investigated. The variables explored as possibly influencing the use of chemotherapy were sex, age, the year of diagnosis, the type of lung cancer, the stage, the index of multiple deprivation and the cancer network of residence. Chi2 analysis and multivariate logistic regression models were used to examine the effect of each of the variables on the use of chemotherapy. The results showed a highly significant trend in use of chemotherapy over time; the adjusted proportion of patients receiving chemotherapy increasing from 13.6% in 1994 to 29.3% in 2003. However, age, cancer network and type of lung cancer had the strongest influence on the use of chemotherapy. This finding is important when we consider that the NHS Cancer Plan aims at improving inequalities in cancer care in the UK.

Acute histopathological changes produced by Penicillium aurantiogriseum nephrotoxin in the rat.

Shredded wheat moulded by an isolate of Penicillium aurantiogriseum elicited progressive histopathological changes at the rat renal cortico-medullary junction during 5 days of dosing, when incorporated into diet as a 20% component. The changes of acute tubular necrosis and regeneration were seen in the P3 segment of the nephron. In rats exposed to contaminated diet for 5 days the histopathological changes regressed in severity by about one-half within a further 4 days on normal diet and by 7 days the tubular epithelium was nearly normal. A partially purified fraction of an alcohol extract, selected by preparative high-voltage electrophoresis and anion exchange and notably rich in amino-compounds, was typically nephrotoxic when given in diet over 4 days. Acute marked tubular necrosis also occurred when the same fraction was given intraperitoneally over a similar period. The acute histological changes provide a rapid bioassay for this Penicillium nephrotoxicity and facilitate the search for the toxic metabolite(s). The cumulative expression of necrosis and repair over only a few days in tubular epithelium suggests that chronic exposure will elicit a more complex pathology which might serve as an experimental model for the idiopathic Balkan endemic nephropathy.

Penicillium aurantiogriseum-induced, persistent renal histopathological changes in rats; an experimental model for Balkan endemic nephropathy competitive with ochratoxin A.

Renal histopathological changes in rats, caused by food partially moulded by a common fungus isolated from an area of nephropathy in Yugoslavia, were differentiated into acute and chronic responses. The acute response to a few days on the diet specifically involved necrosis and concomitant mitosis in proximal tubule cells. More protracted, continuous or intermittent administration of nephrotoxic mould led to a marked karyomegaly in the same corticomedullary region. The phenomenon is more prominent than that induced by treatment with ochratoxin A over a similar period, raising the question of the putative role of such mycotoxins in the etiology of chronic human renal disease.

Suppression of invasive behavior of melanoma cells by stable expression of anti-sense perlecan cDNA.

BACKGROUND: Heparan sulfate proteoglycans are one of the major components of extracellular matrix and are secreted at different levels by several normal and tumoral cells. Perlecan, the basement membrane proteoglycan, has structural domains involved in cell/matrix interactions and growth factor storage. Metastatic melanoma cells show an increase in perlecan expression as compared to low metastatic ones. We examined whether reduction of perlecan expression could down-modulate the malignant phenotype in melanoma clones. MATERIALS AND METHODS: We transfected B16-F10 murine malignant melanoma cells with a perlecan antisense cDNA construct and tested the in vitro behavior of the selected clones. RESULTS: The expression of antisense mRNA corresponded to a reduction of perlecan synthesis. The clones with reduced perlecan synthesis showed a down-regulation of proliferation and invasion. CONCLUSIONS: These results further indicate the importance of perlecan as a regulator of growth factor activity affecting the biological properties of metastatic cells, and suggest the potential use of antisense perlecan DNA in anti-melanoma gene therapy approaches.

Induction of chemotactic and invasive phenotype in BALB/c 3T3 cells by 1,2-dibromoethane transformation.

1,2-Dibromoethane (DBE), which can act as initiating agent, is capable of inducing a malignant phenotype in BALB/c 3T3 cells. Cells transformed with a single noncytotoxic dose formed more progressive tumors in vivo. Almost all animals (95%) receiving the inoculum of two different transformed clones developed tumors within 1 month. In the control group only 55% of the animals developed tumors after 4 months. Treatment with DBE also increased the chemotactic properties of target cells, which also acquired ability to penetrate and colonize a reconstituted basal membrane (matrigel). These data suggest that DBE could play a key role in tumor progression.