A novel snake venom disintegrin that inhibits human ovarian cancer dissemination and angiogenesis in an orthotopic nude mouse model.

OVCAR-5 is a human epithelial carcinoma cell line of the ovary, established from the ascitic fluid of a patient with progressive ovarian adenocarcinoma without prior cytotoxic treatment. The unique growth pattern of ovarian carcinoma makes it an ideal model for examining the anticancer activity of contortrostatin (CN), a homodimeric disintegrin from southern copperhead venom. FACS analysis revealed that OVCAR-5 is integrin alphavbeta3 negative, but alphavbeta5 positive. CN effectively blocks the adhesion of OVCAR-5 cells to several extracellular matrix proteins and inhibits tumor cell invasion through an artificial basement membrane. In a xenograft nude mouse model with intraperitoneal introduction of OVCAR-5 cells, intraperitoneal injection of CN was used for therapy. Tumor dissemination in CN-treated versus control groups was studied by gross examination, and antiangiogenic potential was examined by factor VIII immunohistochemistry and image analysis. CN not only significantly inhibited ovarian cancer dissemination in the nude mouse model, but it also dramatically prevented the recruitment of blood vessels to tumors at secondary sites.

Centriacinar region inflammatory disease in young individuals: a comparative study of Miami and Los Angeles residents.

Semiquantitative measurements of chronic inflammation of the centriacinar region (proximal acinus of lung) were compared between 20 Miami and 18 Los Angeles residents (ages 11-30 years) for whom smoking histories were available. Mean extent and severity scores of four lung sites were higher for Los Angeles than Miami residents, with effect of city statistically significant for extent (P=0.02). Also, maximum scores for extent and severity by city were significantly greater for Los Angeles residents (P=0.02, each), but not by smoking history. Smokers did have higher scores for mean extent and severity (by lung site and smoking history), but neither this nor inclusion of smoking and city in the model reached significance. With respect to maximum extent and maximum severity scores, a stratified comparison of cities by smoking history showed a trend (not significant) toward higher scores for Los Angeles residents. Mean extent and severity scores for the lower lobe were higher for basilar sections than for apical sections (each P<0.001). Cumulative data indicate that expanded pathologic studies are essential for efforts to complete a convergence of epidemiological and experimental data implicating exceedences of the Federal ozone standard as a contributor to human lung injury.

Contortrostatin, a dimeric disintegrin from Agkistrodon contortrix contortrix, inhibits breast cancer progression.

We report the results of a multidisciplinary study on the inhibitory effect of a snake venom disintegrin, contortrostatin, a 13.5 kDa homodimeric protein isolated from Agkistrodon contortrix contortrix (southern copperhead) venom, on breast cancer progression. We demonstrate that contortrostatin binds to integrins and blocks the adhesion of human breast cancer cells (MDA-MB-435) to extracellular matrix (ECM) proteins including fibronectin and vitronectin, but it has no effect on adhesion of the cells to laminin and Matrigel. Contortrostatin also prevents invasion of MDA-MB-435 cells through an artificial Matrigel basement membrane. Daily local injection of contortrostatin (5 microg per mouse per day) into MDA-MB-435 tumor masses in an orthotopic xenograft nude mouse model inhibits growth of the tumor by 74% (p = 0.0164). More importantly, it reduces the number of pulmonary macro-metastasis of the breast cancer by 68% (p < 0.001), and micro-metastasis by 62.4% (p < 0.001). Contortrostatin is not cytotoxic to cancer cells, and does not inhibit proliferation of the breast cancer cells in vitro. However, contortrostatin inhibits angiogenesis induced by the breast cancer, as shown by immunohistochemical quantitation of the vascular endothelial cells in tumor tissue removed from the nude mice. We have identified alpha(v)beta3, an important integrin mediating cell motility and tumor invasion, as one of the binding sites of contortrostatin on MDA-MB-435 cells. We conclude that contortrostatin blocks alpha(v)beta3, and perhaps other integrins, and thus inhibits in vivo progression.

Chronic glandular bronchitis in young individuals residing in a metropolitan area.

A study of 161 Los Angeles County residents aged 12-28 years old who had died sudden violent deaths showed frequent and severe chronic glandular bronchitis (CGB), that is to say grade > or =5 (0-10) chronic inflammation involving at least one, half or more, and all submucosal glands in 53.4%, 21%, and 4.4% of the main stem bronchi, respectively. The mean plasma cell/gland/bronchus was high (> or =5) for 22 subjects (13.7%), while only 2 bronchi (1.2%) had a correspondingly high lymphocyte mean (P<0.001). Of the bronchi, 75.2% were affected by glandular atrophy (> or =5 in 8.1%), 10.6% had neutrophil infiltration of glands, and 3.1% had acute sialadenitis. Of the total of 1040 glands, CGB was found in 83.8% (> or =5 in 26.5%). Of 25 non-smokers identified, 14 (56%) had some degree of CGB in > or =50% of the glands, severe in 7 (26%). Severe CGB in many young individuals raises concern that a subpopulation of living cohorts may have an increased susceptibility to disease and a rising incidence of chronic lung disease. Demographic analysis is pending, but respiratory infection, smoking, adverse socioeconomic factors, and air pollution are all potential causative factors. Since pollution in Los Angeles frequently exceeds air quality standards, an ongoing multicity study is attempting to distinguish between the suspected effects of air pollution and confounding variables.

Nitrogen dioxide (NO2) inhalation, formation of microthrombi in lungs and cancer metastasis.

It is recognized that cancer cells may be introduced into circulation during surgical removal of a malignant neoplasm. The fate of these cells depends upon many factors. In this paper we present findings from an animal model which indicate that inhalation of nitrogen dioxide facilitates blood-borne cancer cell metastasis to lungs by injuring lung capillary endothelium and formation of microthrombi. Lung capillaries were evaluated by light and electron microscopy. The main lesions observed were microthrombi and injury to capillary endothelial cells, following 6 weeks of 0.35 +/- 0.05 ppm NO2 exposure. The blood-borne cancer cell metastasis was studied utilizing B16 melanoma cells in C57Bl/6J mice. A correlation was observed between increased incidence of microthrombi, endothelial cell injury and lung metastasis in exposed animals. Other adverse NO2 effects such as impairment of immune system may also participate. Inhalation of nitrogen dioxide and other air pollutants may play a significant role in enhancement of metastasis and blood vessel associated disorders.

Influence of ambient level NO2 exposure on newborn and adult mice body weights.

A study of the effects of NO2 inhalation on body weights of newborn and adult mice was carried out. A total of 1590 adult mice and 450 newborn mice were evaluated. The level of NO2 exposure was in the ambient range and varied between 0.17 and 0.80 +/- 0.05 ppm depending on experimental design. The duration of exposure was three to twelve weeks, depending upon specific experimental design. The results have indicated that newborn mice are more sensitive than adults to the inhalation of ambient level NO2 and showed significantly lower body weight gains. The findings were interpreted as being indicative of adverse systemic NO2 effects on newborn animals.

The mortality rate from lung metastases in animals inhaling nitrogen dioxide (NO2).

A study was carried out to determine the interrelationship between the inhalation of nitrogen dioxide (0.4 +/- 0.50 ppm), lung metastases development from circulating cancer cells, and death rate from such metastases. C57 BL/6J mice were used in these experiments. Animals were divided into control and NO2-exposed groups, and were exposed to filtered air and 0.4 ppm of NO2, respectively. Following 12 weeks of exposure, all animals were infused intravenously with syngeneic, viable B16 melanoma cells. The results indicate that a subpopulation of NO2-exposed animals showed a significant increase in mortality rate during the early part of the experiment. The interpretation is that animals especially sensitive to the NO2 insult developed extensive metastases at an early stage. The question raised is whether or not the progression of human cancer is influenced by the inhalation of noxious pollutants in the ambient atmosphere.

Effect of 0.3 ppm ozone exposure on type II cells and alveolar walls of newborn mice: an image-analysis quantitation.

Newborn Swiss-Webster mice were exposed to intermittent 0.3 ppm ozone (O3) for 6 wk, and the lungs of 137 exposed and 138 control animals (275 of the 301 in the colony) were suitable for computer-assisted image-analysis quantitation. Data were obtained on numbers and areas of lactate dehydrogenase stained type II cells, and also area, perimeters, and linear intercepts of the alveolar wall. As noted in an earlier study of adult mice, ozone exposure increased all cell and wall measurements. In contrast to the adult animal findings, there was a greater increase in mean type II cell area (p = 0.07) than in numbers of type II cells, with the latter increase falling short of statistical significance. The increase in cell area at the expense of cell number may largely be due to cell pairing or multicell clustering, events that would mask type II cell hyperplasia. Ozone effects on the type II cell population implicate damage to the type I alveolar lining cells. Moreover, the increases in alveolar wall measurements that were found in both the adult and developing mouse lung imply an alteration of the lung scaffolding, and this raises the question of impaired regeneration of the epithelial lining.

A new relationship between air pollutant inhalation and cancer.

Many studies have been conducted to investigate the effects of different air pollutants on health. Our studies have focused on the effects of nitrogen dioxide (NO2), and recently we reported that inhalation of low levels of NO2 can facilitate cancer cell metastasis. The study described herein utilized the same B16 mouse melanoma metastasis model of previous investigations, but under different NO2 exposure conditions. The results provide further evidence that inhalation of ambient level NO2 (0.4 ppm) or polluted urban ambient air play a role in facilitation of blood-borne cancer cell metastasis. In addition, results show different patterns of melanoma cell distribution in the lungs of NO2- and ambient-air exposed animals. They also indicate that extended periods of clean air between NO2 exposures may diminish the severity of the insult in the less sensitive animals. It is our conclusion that the results provide strong support for the need of improved air quality and for reduction of noxious pollutants in urban ambient air.

Hyperplasia of Type 2 pneumocytes following 0.34 ppm nitrogen dioxide exposure: quantitation by image analysis.

Swiss Webster male mice were exposed to intermittent 0.34 ppm nitrogen dioxide for 6 wk. Quantitative image analysis showed increased Type 2 cell numbers in each of the three lobes measured, with and without adjustment to alveolar wall measurements for lung volume normalization (e.g., P less than .037 for Type 2 cell number adjusted to alveolar wall perimeters, combined lobe analysis of variance). The exposed animals dominated the upper quartile ranking of the cell number/alveolar area ratio computations (P less than .025), which implied the presence of an especially susceptible subpopulation of animals. The Type 2 cell increase is believed to result from damage and loss of Type 1 cells, the reversibility and progression of which are presently unknown. The data also suggest an increased size of the Type 2 cell, and possibly slight atelectasis and/or edema of the alveolar walls.

Influence of 0.5 ppm nitrogen dioxide exposure of mice of macrophage congregation in the lungs.

The lungs of 12 mice, half of which were exposed to continuous 0.5 ppm nitrogen dioxide for 3 weeks, were explanted in culture, and the instances of macrophage congregation were quantitated according to numbers of target cells involved, categories of congregation from three to 11 or more, numbers of macrophages participating in each category for the total cultures, and the influence of delaying explantation for 24 and 96 hr. A total of 9042 macrophages and 2140 epithelial and spindle target cells were counted in the outgrowths from 306 explants. The incidence of macrophage congregation (or numbers of target cells) was greater for the cultures from the NO2-exposed animals, both with respect to total incidences between groups (p leads to) and the 0-hr (p less than 0.001) and 24-hr (p less than 0.01) culture subgroups. In addition, the values for T3 to T6 macrophage congregation were individually and consistently greater for the exposed animal group. Postmortem interval stress at 96 hr appeared to result in large colonies, but they were reduced greatly in number. Also the incidence of macrophage congregation fell by 28% as compared to 0-hr and 24-hr subgroups.