Study of protoporphyrin IX elimination by body excreta: a new noninvasive cancer diagnostic method?

This paper describes the elimination of porphyrins by feces. It was demonstrated that porphyrin accumulates substantially more in tumors than in normal tissues, and consequently more PPIX reaches the blood of patients and animals with tumors, and then, it needs to be eliminated. The fluorescence of feces revealed that there are large amounts of PPIX in the excreta of animals with cancer comparing with healthy animals. The autofluorescence of feces porphyrin extracted with acetone was analyzed using fluorescence spectroscopy of animals inoculated with DU145 cells into the prostate and healthy animals to monitor the PPIX concentration. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences were observed in autofluorescence intensities measured in the 575-725 nm spectral regions for the studied groups. The results showed a noninvasive, simple, rapid and sensitive method to detect cancer by feces analysis.

Endostatin- and interleukin-2-expressing retroviral bicistronic vector for gene therapy of metastatic renal cell carcinoma.

BACKGROUND: Metastatic renal cell carcinoma (mRCC) is one of the most treatment-resistant malignancies. Despite all new therapeutic advances, almost all patients develop resistance to treatment and cure is rarely seen. In the present study, we evaluated the antitumor effect of a bicistronic retrovirus vector encoding both endostatin (ES) and interleukin (IL)-2 using an orthotopic metastatic RCC mouse model. METHODS: Balb/C-bearing Renca cells were treated with NIH/3T3-LendIRES-IL-2-SN cells. In the survival studies, mice were monitored daily until they died. At the end of the in vivo experiment, serum levels of IL-2 and ES were measured, the lung was weighed, and the number of metastatic nodules, nodule area, tumor vessels and proliferation of tumor-infiltrating Renca cells were determined. RESULTS: Inoculation of NIH/3T3-LendIRES-IL-2-SN cells resulted in an increase in ES and IL-2 levels in the treated group (p < 0.05). There was a significant decrease in lung wet weight, lung nodule area and tumor vessels in the treated group compared to the control group (p < 0.001). The proliferation of Renca cells in the bicistronic-treated group was significantly reduced compared to the control group (p < 0.05). Kaplan-Meier survival curves showed that the probability of survival was significantly higher for mice submitted to bicistronic therapy (log-rank test, p = 0.0016). Bicistronic therapy caused an increase in the infiltration of CD4, CD4 interferon (IFN)γ-producing, CD8, CD8 IFNγ-producing and natural killer (CD49b) cells. CONCLUSIONS: Retroviral bicistronic gene transfer led to the secretion of functional ES and IL-2 that was sufficiently active to: (i) inhibit tumor angiogenesis and tumor cell proliferation and (ii) increase the infiltration of immune cells.

Endostatin, an antiangiogenic protein, is expressed in the unilateral ureteral obstruction mice model.

BACKGROUND: Extracellular matrix accumulation, epithelial-to-mesenchymal transition, tubular atrophy and loss of peritubular capillary network are hallmarks of tubulointerstitial injury in progressive renal diseases. In this study, we analyzed endostatin expression in kidneys subjected to unilateral ureteral obstruction (UUO). METHODS: Collagen XVIII mRNA expression was evaluated by real-time polymerase chain reaction (PCR). Endostatin and CD31 protein levels were analyzed by Western blot and immunohistochemistry. In vitro quantification of collagen XVIII and fibrosis-related genes in HK2 cells was performed by real-time PCR. RESULTS: UUO significantly increased collagen XVIII mRNA expression and released a 30-kDa endostatin fragment. Immunohistochemistry revealed endostatin expression increased in injured tissue, mainly on tubular cells. Of interest, expression of CD31 was significantly reduced by UUO. Endostatin administration in vitro did not modify the expression of genes related to fibrosis development. However, in vitro TGF-beta1 administration induced expression of collagen XVIII/endostatin mRNA in human tubular cells. CONCLUSION: Endostatin is expressed during the progression of renal fibrosis in vitro and in vivo, suggesting a role for endostatin in development of tubulointerstitial injury.

Early diagnosis of prostate cancer by citrate determination in urine with europium-oxytetracycline complex.

Normal prostate tissue contains high levels of citrate. In the presence of prostate cancer, the citrate level is diminished. In this paper we show that it is possible to use europium-oxytetracycline complex as a citrate fluorescent probe and consequently as a prostate cancer probe. We analyzed normal nude male mice urine and urine from nude male mice in which prostate cancer was induced by intraprostatic inoculation of DU145 cells. The urine samples were collected from the animals at the 7th, 14th, 21st, and 35th days after the surgery procedures. The intensity of europium emission at 615 nm in europium-oxytetracycline complex in the presence of citrate increases linearly. The citrate concentrations were determined from a calculated calibration curve. A concentration decrease in malignant prostate urine from the normal (PBS group) urine value from ~8.0 mM to ~2.4 mM (tumor group at 35th day) was found. The obtained results indicated that europium-oxytetracycline provides a significant biomarker for prostate cancer detection with a direct, accurate, noninvasive, and non-enzymatic method for measurement of citrate in biological fluids.

Investigation of the radiation risk due to environmental contamination by 241Am from lightning rods disposed at uncontrolled garbage dumps.

Radioactive lightning rods were manufactured in Brazil until 1989, when the licenses for using radioactive sources in these products were lifted by the national nuclear authority. Since then, these rods have been replaced by the Franklin type and collected as radioactive waste. However, only 20% of the estimated total number of installed rods has been delivered to the Brazilian Nuclear Commission. This situation causes concern, since there is the possibility of the rods to be disposed as domestic waste. In Brazil, 64% of the municipal solid waste is disposed at garbage dumps without sufficient control. In addition, (241)Am, the radionuclide most commonly employed, is classified as a high-toxicity element, when incorporated. In the present study, (241)Am migration experiments were performed by means of a lysimeter system, in order to evaluate the risk of contamination caused by radioactive lightning rods disposed as common solid waste. (241)Am sources removed from lightning rods were placed inside lysimeters filled with organic waste that was collected at the restaurant of the Instituto de Pesquisas Energéticas e Nucleares. The generated leachate was periodically analyzed, and characteristics such as pH, redox potential, solid content and the concentration of the radioactive material were determined. The equivalent dose for members of the public was calculated considering ingestion of contaminated drinking water as the major path of exposure. Estimated doses were about 20-times below the effective dose limit of 1 mSv year(-1) for members of the public as recommended by the International Commission on Radiological Protection. This suggests the radiation risk caused by lightning rods disposed at uncontrolled garbage dumps to be low. It should be noted, however, that the number of investigated lightning rods was quite small. The results of this study might therefore not be entirely representative and should be interpreted with care. They provide, however, a very first basis for characterizing the transfer of (241)Am from lightning rods to the human food chain.

Endostatin expression in the murine model of ischaemia/reperfusion-induced acute renal failure.

BACKGROUND: Renal ischaemia-hypoxia is a leading cause of acute renal failure, a clinical condition associated with rapid loss of renal function and high rates of mortality. Renal proximal tubular cells are the most severely injured during renal ischaemia, caused by the breakdown of the extracellular matrix of the tubular basement membrane. Endostatin is the C-terminal fragment of collagen XVIII generated by proteolytic cleavage and it is well-known as being an inhibitor of angiogenesis. In vitro, endostatin inhibits endothelial cell proliferation and migration, as well as tubule formation. In vivo, it has a potent inhibitory effect on tumour growth. In this study, we analysed endostatin gene expression in C57BL/6 mouse kidneys subjected to ischaemia/reperfusion. METHODS: Ischaemic renal failure was induced via 45 min of bilateral occlusion of the renal artery and vein, followed by 12 h or 24 h of reperfusion. Whole-kidney homogenate and total RNA were extracted for examination by western blot analysis and quantitative polymerase chain reaction. The immunohistological examination revealed increased endostatin expression in injured kidney, mainly in the proximal tubule and collecting ducts. RESULTS: Endostatin/collagen XVIII mRNA and protein expression increased during ischaemia and within 12 h of reperfusion. In the western blot assay, we identified increased expression of the 30 kDa endostatin-related fragment and of matrix metalloproteinase-9. CD31 was significantly expressed during reperfusion (P < 0.05). Immunohistological examination revealed glomerular and tubulointerstitial expression of endostatin. CONCLUSION: These data suggest the local synthesis of a 30 kDa endostatin-related fragment following acute renal failure and suggest its role in the modulation of renal capillary density.

Lack of association between matrix metalloproteinase-1 (MMP-1) promoter polymorphism and risk of renal cell carcinoma.

OBJECTIVE: Investigate the possible association of insertion/deletion (2G/G) polymorphism at nucleotide -1607 of the MMP-1 promoter with the development and progression of renal cancer. MATERIALS AND METHODS: In this study, we genotyped 217 individuals, 99 patients with renal cell carcinoma (RCC) and 118 controls without cancer. DNA specimens were extracted from epithelial buccal cells and paraffin-embedded tissue of RCC patients and from epithelial buccal cells and blood cells of healthy controls. RESULTS: The difference in frequency of 2G/2G genotype between controls (22.9%) and RCC patients (28.6%) was not statistically significant (p = 0.461). We also did not find correlation between 2G/2G and histological type of RCC. The comparison of genotype distribution and frequency of 2G allele in different populations showed a strong variability of 2G allele frequency among the different ethnic groups. This fact may influence on the collaboration of this 2G allele in RCC or others diseases. CONCLUSION: Our data suggest that the matrix metalloproteinase-1 (MMP-1) promoter polymorphism may not play a significant role in renal cell carcinoma patients in Brazil.

Association of endothelial nitric oxide synthase gene intron 4 polymorphism with end-stage renal disease.

BACKGROUND: Nitric oxide (NO) released from endothelial cells is related to the maintenance of physiological vascular tone. The impairment of endothelial NO generation brought about by gene polymorphism is considered one of the deterioration factors in progressive renal disease. In the endothelial nitric oxide synthase (eNOS) intron 4 polymorphism, the presence of the aa genotype has been associated with cardiovascular and renal disease. The aim of this study was to investigate the presence of eNOS gene intron 4 polymorphism in patients with end-stage renal disease (ESRD). METHODS: A total of 114 patients and 94 controls were studied. DNA specimens were extracted from blood and amplified by polymerase chain reaction. The alleles were separated by agarose gel electrophoresis. Genotype distribution and allele frequencies were compared between groups using the chi-squared test. RESULTS: Statistical analysis revealed that the frequency of the eNOS4 genotype aa was significantly different in ESRD patients and in controls (P=0.016, OR=2.07, CI 95%: 1.14-3.74). There was also a statistically significant difference between ESRD patients and controls regarding allele carriers (P=0.004; OR=2.26; CI 95%: 1.29-3.96). When the frequencies of allele carriers in the diabetic nephropathy group and in the control group were compared, a significant difference was found (P=0.034, OR=2.28; CI 95%: 1.04-5.00). CONCLUSION: This study showed a strong correlation between eNOS4a polymorphism and end-stage renal disease.

Urea hydrogen peroxide determination in whole blood using europium tetracycline probe.

We introduce the use of a lanthanide complex, tetracycline-europium, for the clinical diagnosis of urea hydrogen peroxide in human whole blood. The values obtained agree with the urea concentration variation verified in 49 patients, including 12 predialysis, 12 peritoneal, and 15 dialysis subjects, and 10 controls. This method is noninvasive and can help in the identification of renal and cardiac diseases.

Lack of association between matrix metalloproteinase-1 (MMP-1) promoter polymorphism and risk of renal cell carcinoma

OBJECTIVE: Investigate the possible association of insertion/deletion (2G/G) polymorphism at nucleotide -1607 of the MMP-1 promoter with the development and progression of renal cancer MATERIALS AND METHODS: In this study, we genotyped 217 individuals, 99 patients with renal cell carcinoma (RCC) and 118 controls without cancer. DNA specimens were extracted from epithelial buccal cells and paraffin-embedded tissue of RCC patients and from epithelial buccal cells and blood cells of healthy controls RESULTS: The difference in frequency of 2G/2G genotype between controls (22.9 percent) and RCC patients (28.6 percent) was not statistically significant (p = 0.461). We also did not find correlation between 2G/2G and histological type of RCC. The comparison of genotype distribution and frequency of 2G allele in different populations showed a strong variability of 2G allele frequency among the different ethnic groups. This fact may influence on the collaboration of this 2G allele in RCC or others diseases CONCLUSION: Our data suggest that the matrix metalloproteinase-1 (MMP-1) promoter polymorphism may not play a significant role in renal cell carcinoma patients in Brazil.