Desanka Výbohová

Melatonin potentiates the anti-tumour effect of pravastatin in rat mammary gland carcinoma model

Previous studies in the field of cancer research have suggested a possible role for statins in the reduction of risk in certain malignancies. The purpose of these studies was to examine the chemopreventive effects of pravastatin alone and in combination with pineal hormone melatonin in the N‐methyl‐N‐nitrosourea‐induced mammary carcinogenesis model. Pravastatin was given orally (1 00 mg/kg) and melatonin was added to the water (20 μg/ml). Chemoprevention began seven days prior to carcinogen administration and subsequently continued for 15 weeks until autopsy. At autopsy, mammary tumours were removed and prepared for histopathological and immunohistochemical analysis. Parameters of experimental carcinogenesis, mechanism of action (biomarkers of apoptosis, angiogenesis and proliferation) and side effects after long‐term treatment in animals were assessed. Pravastatin alone suppressed tumour frequency by 20.5% and average tumour volume by 15% compared with controls. Combined administration of the drugs decreased tumour frequency by 69% and lengthened tumour latency by nine days compared with control animals. The ration between high and low grade carcinomas was apparently reduced in both treated groups. The analysis of carcinoma cells showed significant expression increase in caspase‐3 and caspase‐7 after pravastatin treatment; however, combined treatment even more pronounced increase in the expression of both caspases. Regarding VEGFR‐2 expression, a small effect in carcinomas of both treated groups was found. In plasma metabolism evaluation, pravastatin alone significantly decreased levels of glucose and triacylglycerols. Our results suggest a mild anti‐neoplastic effect of pravastatin in this rat mammary gland carcinoma model. Statins co‐administered with other suitable drug (e.g. melatonin) should be further evaluated for tumour‐preventive properties.

Proton magnetic resonance spectroscopy and its diagnostically important metabolites in the brain.

This review provides a brief summary of the physical basis of magnetic resonance spectroscopy ((1)H MRS) and its application in the human brain. We discuss the chemical structure, signal properties, biological function, normal spatial distribution and diagnostic potential of the more significant metabolites detectable in brain tissue: N-acetylaspartate, N-acetylaspartylglutamate, choline-containing substances, creatine, phosphocreatine, myo-inositol, glutamine and glutamate. We also present a few notes on the importance of proper spectral quantification and contemporary trends in ¹H MRS. [corrected].

Combination of Pitavastatin and melatonin shows partial antineoplastic effects in a rat breast carcinoma model.

Our previous results indicated significant tumor-suppressive effects of different statins in rat mammary carcinogenesis. The purpose of this experiment was to examine the chemopreventive effects of Pitavastatin alone and in combination with the pineal hormone melatonin in the model of N-methyl-N-nitrosourea-induced mammary carcinogenesis in female Sprague-Dawley rats. Pitavastatin was administered dietary (10mg/kg) and melatonin in an aqueous solution (20μg/ml). Chemoprevention began 7 days prior to carcinogen administration and subsequently continued for 15 weeks until autopsy. At autopsy, mammary tumors were removed and prepared for histopathological and immunohistochemical analysis. Compared to controls, Pitavastatin alone reduced average tumor volume by 58% and lengthened latency by 8 days; on the other hand, the drug increased tumor frequency by 23%. Combined administration of Pitavastatin with melatonin decreased tumor frequency by 23%, tumor volume by 44% and lengthened tumor latency by 5.5 days compared to control animals. The analysis of carcinoma cells showed significant increase in caspase-3 expression in both treated groups and a tendency of increased caspase-7 expression after Pitavastatin treatment alone. Significant expression decrease of Ki67 was found in carcinoma cells from both treated groups. Compared to control carcinoma cells, Pitavastatin alone increased VEGF expression by 41%, however melatonin totally reversed its undesirable effect. Pitavastatin combined with melatonin significantly increased femur compact bone thickness in animals. Pitavastatin alone decreased plasma triglycerides and total cholesterol levels, however it significantly increased levels of glucose. In summary, our results show a partial antineoplastic effect of Pitavastatin combined with melatonin in the rat mammary gland carcinoma model.

Young Barley Indicates Antitumor Effects in Experimental Breast Cancer In Vivo and In Vitro.

ABSTRACT The effect of dietary administered young barley containing a mixture of phytochemicals to female rats for the prevention of N-methyl-N-nitrosourea-induced mammary carcinogenesis was evaluated. After carcinogen administration (14 wk), mammary tumors were removed and prepared for histopathological and immunohistochemical analysis. Moreover, in vitro evaluation of possible mechanisms in MCF-7 breast cancer cell line was performed. Barley (0.3%) demonstrated mild antitumor effect in mammary carcinogenesis, yet 3% barley did not further improve this effect. Immunohistochemical analysis of rat tumor cells in treated groups showed significant increase in caspase-3 expression and significant reduction in Ki67 expression. In addition, 3% barley significantly decreased dityrosine levels versus control. Barley in higher dose significantly decreased serum low-density lipoprotein-cholesterol in rats. In vitro studies showed that barley significantly decreased survival of MCF-7 cells in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and significantly decreased 5-bromo-20-deoxyuridine incorporation versus control. Barley prevented cell cycle progression and extended incubation with barley showed significant increase in the percentage of annexin V/propidium iodide-positive MCF-7 cells. Our results propose an antitumor effect for the mixture of phytochemicals present in young barley in a breast cancer model.

Quantitative comparison of angiogenesis and lymphangiogenesis in cutaneous lichen planus and psoriasis: Immunohistochemical assessment

Recent experimental studies revealed that angiogenesis and lymphangiogenesis are closely related to chronic inflammation. The present study aims to evaluate quantitative changes of blood and lymphatic microcirculatory beds in cutaneous lichen planus (CLP) and psoriatic lesions using immunohistochemical analysis with antibodies to CD34, D2-40 and VEGF. Morphometric software was used to determine the area of blood and lymphatic vessels (BVA and LVA) and also the VEGF positive area. Statistical analysis of these parameters confirmed a significant enlargement of both the blood and lymphatic microcirculatory beds in psoriatic and CLP lesions. BVA in CLP lesions was increased by 56% however this augmentation was not as great as in psoriatic lesions where BVA was increased by 123%. Interestingly, LVA in psoriatic and CLP lesions was increased equally by 85%. The strongest VEGF expression was detected in psoriatic lesions, with lower, but still significant, overexpression in CLP lesions. VEGF-C was significantly increased in both psoriatic and CLP lesions in comparable level. Noticeably higher VEGF and VEGF-C expression was observed in the epidermis than in the dermis. Finally, our results indicate that the level of angiogenesis is considerably greater in psoriatic lesions than in CLP lesions, but the level of lymphangiogenesis is equal in both psoriatic and CLP lesions.

Quantitative immunohistochemical assessment of blood and lymphatic microcirculation in cutaneous lichen planus lesions.

Latest advances have brought to light the hypothesis that angiogenesis and lymphangiogenesis are tightly connected to some chronic inflammatory diseases. The present study focuses on immunohistochemical assessment of the quantitative changes in the blood and lymphatic microcirculatory bed in common chronic dermatosis - cutaneous lichen planus. Double immunohistochemistry with CD34 and podoplanin antibodies was used to detect blood and lymphatic endothelium, while anti-human VEGF was used for the observation of a key angiogenesis and lymphangiogenesis inducer. Morphometric analysis was performed with QuickPhoto Micro image analysis software. Results confirmed statistically significant enlargement of both the blood and lymphatic microcirculatory beds. Compared to healthy skin, cutaneous lichen planus lesions revealed 1.6 times enlarged blood microcirculatory bed and 1.8 times enlarged lymphatic microcirculatory bed. Vascular endothelial growth factor (VEGF) expression in lesional skin was significantly higher in the epidermis (19.1 times increase) than in the dermis (10.3 times increase). These findings indicate a tight association of angiogenesis and lymphangiogenesis with the pathogenesis of cutaneous lichen planus.

Expression and significance of survivin in colorectal high grade and low grade adenomas.

We examined immunohistochemically the expression pattern of a potential tumor biomarker survivin in a panel of 116 tubular adenomatous polyps to determine its association with clinicomorphological parameters such as age of patients, size of polyps, degree of dysplasia and polyp localization. In each section, the subcellular localization of survivin antigen and the intensity of staining were assessed. Overall, survivin was expressed in 90 cases (77.6%). Cytoplasmic positivity was observed in 46/116 cases (39.7%), while nuclear and combined nuclear and cytoplasmic reaction in 44/116 cases (37.9%). High grade dysplasia was diagnosed in 52 cases (44.8%) and low grade dysplasia in 64 cases (55.2%). Statistical analysis revealed a significant correlation between subcellular survivin localization and the degree of dysplasia, size of polyps and colon localization. On the other hand, survivin expression pattern did not correlate with the age of patients. Statistically significant trend was confirmed between intensity of survivin immunoreaction and tumor size and dysplasia grade, and also the trend between negative/strong survivin intensity and polyp localization. Another statistically significant association was found between the degree of dysplasia and the size of polyps. Our findings revealed that survivin is frequently expressed in different subcellular compartments of adenoma cells. Our recent results suggest that the nuclear and combined nuclear and cytoplasmic survivin localizations are strongly associated with poor prognostic parameters in the assessment of colon adenomas. Thus, survivin may represent a promising biomarker in immunohistochemical evaluation of these lesions.

Survivin expression in breast lobular carcinoma: correlations with normal breast tissue and clinicomorphological parameters.

The antiapoptotic protein survivin is rarely expressed in normal adult differentiated tissues, but it is often detected in their malignant counterparts. Immunohistochemically, we evaluated survivin expression in 19 cases of normal breast tissue and 64 cases of lobular breast carcinoma. The intensity of staining, percentage of labeled cells and subcellular location of survivin were assessed. We analyzed the quantitative differences of survivin expression between normal breast tissue and carcinomas. We also correlated survivin expression pattern in carcinomas with clinicomorphological parameters such as age of patients, grade, stage and size of primary tumor, lymph node metastasis, vascular invasion as well as estrogen and progesterone status. Survivin was detected in 10/19 cases of normal breast tissue (52.6%) and in 55/64 cases of lobular breast carcinoma (86%). The statistical analysis confirmed significant correlations between the assessed parameters in normal breast and lobular carcinoma. Furthermore, the expression of estrogen correlated significantly with the subcellular localization and intensity of survivin in carcinoma. However, no significant correlation was shown with regard to other clinicomorphological parameters. Our results suggest that survivin may be a valuable diagnostic marker, as well as a new independent prognostic parameter, in lobular breast carcinoma. Finally, our data support the hypothesis that lobular and ductal breast carcinomas seem to be different clinicomorphological entities.

Role of high-fat diet on the effect of pioglitazone and melatonin in a rat model of breast cancer.

The risk of cancer may be modulated by drugs with pleiotropic effects and diet has been implicated in the efficacy of treatment. The oncopreventive effects of the antidiabetic drug pioglitazone (PIO) and the anti-insomnia drug melatonin (MT), in vivo, have been proven before, but using a standard-type diet. This study evaluated the impact of a high-fat diet on their efficacy in chemically induced mammary carcinogenesis in Sprague–Dawley rats. Mammary tumours were induced by N-methyl-N-nitrosourea (50 mg/kg, intraperitoneal, on the 41st postnatal day). PIO and MT administration was initiated 11 days before the carcinogen application and lasted until the termination of the experiment at 16 weeks. PIO was administered in a diet (10% fat) at a concentration of 100 ppm and MT was administered in tap water (20 mg/l). PIO, MT and the combination did not significantly alter the basic tumour growth parameters. However, histopathology showed a decrease in the high-grade/low-grade tumour ratio, particularly in animals that received combined treatment (P<0.01). Semiquantitative immunohistochemistry indicated the proapoptotic effect of chemoprevention, particularly in the drug combination group (P<0.01), but no changes in tumour cell proliferation and angiogenesis were recorded. Results were evaluated by one-way analysis of variance or the Mann–Whitney U-test, respectively. PIO and MT, alone or in combination, administered to rats fed a high-fat diet reduced the proportion of high-grade tumours and promoted apoptosis in an in-vivo breast cancer model, although it did not suppress tumour growth. The impact of high dietary fat content on the chemopreventive efficacy of these and other substances should be considered in human studies.

Survivin in breast lesions: immunohistochemical analysis of 196 cases

We examined the survivin expression pattern by immunohistochemistry in 43 fibroadenomas and 153 ductal carcinomas of the breast. The subcellular localization of survivin and the intensity of immunoreaction were assessed. We analyzed the differences of survivin expression between fibroadenomas and carcinomas. We also correlated the survivin expression pattern in carcinomas with other clinicomorphological parameters such as the age of patients, the grade and size of primary tumor as well as the lymph node metastasis. Overall, survivin was detected in 107/153 carcinomas (69.9%) and in 26/43 fibroadenomas (60.5%). Statistical analysis confirmed significant correlations between the assessed parameters in fibroadenomas and carcinomas. Grade of carcinomas was significantly related to survivin expression in both subcellular localization and the intensity of immunoreaction. Tumor grade 3 was associated with nuclear positivity and combined nuclear and cytoplasmic localization. Carcinomas larger than 20 mm showed nuclear and combined localization in 81% of cases and higher intensity of survivin immunoreaction was also notably related to larger carcinomas. Statistically significant differences were also observed between subcellular survivin localization and intensity of immunoreaction. Our result suggest that nuclear accumulation of survivin is associated with proliferative fenotype and survivin was shown to be a worse prognostic marker in breast ductal carcinoma.