Micro-mechanical fingerprints of the rat bladder change in actinic cystitis and tumor presence.

Tissue mechanics determines tissue homeostasis, disease development and progression. Bladder strongly relies on its mechanical properties to perform its physiological function, but these are poorly unveiled under normal and pathological conditions. Here we characterize the mechanical fingerprints at the micro-scale level of the three tissue layers which compose the healthy bladder wall, and identify modifications associated with the onset and progression of pathological conditions (i.e., actinic cystitis and bladder cancer). We use two indentation-based instruments (an Atomic Force Microscope and a nanoindenter) and compare the micromechanical maps with a comprehensive histological analysis. We find that the healthy bladder wall is a mechanically inhomogeneous tissue, with a gradient of increasing stiffness from the urothelium to the lamina propria, which gradually decreases when reaching the muscle outer layer. Stiffening in fibrotic tissues correlate with increased deposition of dense extracellular matrix in the lamina propria. An increase in tissue compliance is observed before the onset and invasion of the tumor. By providing high resolution micromechanical investigation of each tissue layer of the bladder, we depict the intrinsic mechanical heterogeneity of the layers of a healthy bladder as compared with the mechanical properties alterations associated with either actinic cystitis or bladder tumor.

Evaluation of the prognostic value of fibrinolytic elements in invasive breast carcinoma patients.

Breast cancer (BrC) is one of the most serious oncological problems in the world. The aim of the study was to evaluate concentrations of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) and their ratios: t-PA/PAI-1 and PAI-1/t-PA in breast cancer patients and in healthy individuals and to estimate the ability of fibrinolytic parameters in predicting neoplasm disease and disease relapse. One hundred and five women were enrolled in the study, including 60 cases with primary BrC, (M0) and 45 healthy females. Follow-up was completed in all BrC patients with a 16.7% recurrence rate. An immunoassay of t-PA, PAI-1 in all cases was made as well as the immunohistochemistry of estrogen and progesterone receptors, human epidermal growth factor receptor 2, E-cadherin, and Ki-67 was performed in BrC subjects. A significantly higher PAI-1 concentration in breast cancer patients below the age of 55 than in controls was obtained. According to the ROC curve analysis, the PAI-1 concentration demonstrates the most accurate prognostic value with the cut-off point at 33.91 ng/ml, with 90% sensitivity and 36% specificity, which discriminates between controls and cancer patients. However, t-PA presents the highest area under the receiver-operating characteristic curves (AUCROC)=0.634 in predicting disease relapse with the cut-off value of 5.3 ng/ml. According to the Kaplan-Meier curves, a high concentration of t-PA (>5 ng/ml) and a lower PAI-1/t-PA ratio (<7.5) are associated with shorter survival. Evaluation of plasma t-PA and PAI-1 concentrations may deliver relevant prognostic information for breast cancer patients.

Assessment of leptin-to-adiponectin ratio in prediction of insulin resistance and nutrition status in a geriatric female population.

Both obesity and malnutrition leading to cachexia and sarcopenia are relevant risk factors in the development of many diseases. They also increase mortality, also prolong hospitalisations and convalescence, and undoubtedly increase the cost of treatment, mostly in the elderly populations. The aim of the study was to assess the relationship between the levels of leptin and adiponectin with regard to insulin resistance and malnutrition status by studying a senior female population and to evaluate predictors of insulin resistance and malnutrition. A total of 88 elderly females were enrolled prospectively with a median age of 75 years. Anthropometric and biochemical parameters (fasting glucose, insulin, folic acid, vitamin B12 concentrations, lipid profile, complete blood count) were recorded along with a full geriatric assessment, have been made in all participants. A comprehensive nutritional phenotype has been established. Leptin and adiponectin concentrations were measured by applying immunoassay techniques. Lipid profile and other parameters were performed by biochemical methods. We observed significant decreases of albumin, alanine aminotransferase, insulin, and triglycerides concentrations with age. The risk of insulin resistance based on HOMA-IR index was decreased with age. Significantly higher concentrations of leptin, leptin-to-adiponectin ratio (LAR), hsCRP, fasting glucose, insulin in the insulin resistant subgroup in respect of normal sensitivity insulin cases were noted. The concentrations of albumin, aspartate aminotransferase, alanine aminotransferase and total cholesterol were significantly lower in those patients at risk of malnutrition than in the well-nourished subjects. LAR reached the most accurate AUCROC = 0.705 for insulin resistance prediction, with a cut-off value at 3.85. The greatest diagnostic power was presented by the albumin concentration with AUCROC = 0.761 and then LAR 0.718 in discriminating between well-nourished patients and those at risk of malnutrition. We suggest that the leptin-to-adiponectin ratio is suitable as a marker of insulin resistance and nutritional status in the elderly.

Heparanase link between vasculogenesis and angiogenesis as well as a predictive factor of a shorter survival rate.

Heparanase concentration is low in normal epithelia cells but its overexpression is reported in many carcinomas, including sarcomas and haematological malignancies. The purpose of this study was to investigate the association with selected angiogenic parameters as well as in the number of circulating endothelial progenitors (EPCs) in respect to low, moderate and high concentrations of heparanase. Also, we estimated the diagnostic usefulness of the heparanase concentration for disease recurrence prediction in breast cancer cases. Eighty-six patients with IA-IIB stage invasive breast carcinoma who passed a comprehensive clinicopathologic evaluation were included in the study. The median tumour diameter was 1.5 cm. Twenty cases showed lymph node metastasis (N1). Follow-up was completed in all patients a median follow-up was 33.5 months with a 11.6% recurrence rate. An immunoassay of selected angiogenic parameters, heparanase, as well as an immunohistochemistry of oestrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2), Ki67 and E-cadherin was performed in all cases. Circulating EPCs were determined by flow cytometry. Higher levels of heparanase in oestrogen and progesterone receptor negative cancers than in positive ones were noted. A higher concentration of heparanase was observed in T2 cases than T1 subjects. Significant positive associations between circulating EPCs, soluble forms of VEGF receptors and increasing plasma levels of heparanase were obtained. Follow-up revealed a significantly higher incidence of disease relapse in breast cancer patients with high baseline concentrations of heparanase. Heparanase was the most accurate biomarker with an AUCROC = 0.72. The cut-off value of 213.74 pg/mL was identified in order to discriminate between disease recurrence patients and those without disease relapse. We suggest, that a high concentration of heparanase next to tumour size and oestrogen and progesterone receptor expression may serve as an indicator of a more an aggressive character of tumour cells and a shorter survival rate.

Elevated plasma levels of tissue factor as a valuable diagnostic biomarker with relevant efficacy for prediction of breast cancer morbidity.

The aim of this study was to evaluate the concentrations of tissue factor (TF) and its inhibitor (TFPI), vascular endothelial growth factor A (VEGF-A), soluble forms of VEGF receptors type 1 and 2 (sVEGFR1 and aVEGFR2) in patients diagnosed with luminal A breast cancer (BrC) and in healthy individuals and to find associations of analyzed factors with demographic, clinical and pathological characteristics in a homogeneous breast cancer group. Study group consisted of 60 women aged 40 - 69 years, diagnosed with luminal-A subtype of BrC, without distant metastases (M0). Control group comprised 40 healthy women aged 45 - 63 years. Blood samples were collected from each patient in order to determine plasma levels of TF, TFPI, VEGF-A and sVEGFR1 and sVEGFR2. The examined parameters were measured by enzyme-linked immunosorbent assay (ELISA). The capacity of angiogenic and hemostatic parameters in predicting neoplasm disease was analyzed using receiver operating characteristic (ROC) curve analysis. According to ROC curve analysis, the optimum cut-off point for TF was 304.58 pg/ml, with 100% sensitivity and 100% specificity, which was calculated to discriminate between controls and malignancy patients. In luminal A BrC patients there were significantly higher concentrations of VEGF-A and TF than in controls. On the contrast the levels of sVEGF receptors type 1 and 2 as well as TFPI in luminal-A BrC cases were significantly lower in respect to healthy volunteers. Levels of examined factors in the study group varied depending on age, menopausal status, lymph node involvement and histological type. We concluded that altered levels of examined factors in patients diagnosed with luminal-A breast cancer indicate increased activation of angiogenesis and hemostasis. The results obtained may be indicative of a mutual connection between angiogenesis and hemostasis processes in tumor development and progression. Clinical and pathological parameters may possibly affect levels of angiogenic and coagulation factors.

Increased number of endothelial progenitors in peripheral blood as a possible early marker of tumour growth in post-menopausal breast cancer patients.

The aim of the study was to evaluate the number of circulating endothelial progenitor cells (circulating EPCs) in the blood of patients diagnosed with breast cancer and to make an attempt at finding associations with the number of circulating EPCs and selected clinic-pathological factors; TNM and histological grading, molecular subtype of breast cancer, hormonal status, the expression of Ki-67 and the size of tumour. The study involved 96 Caucasian ethnicity post-menopausal women. Sixty-six women aged 48 - 63 (mean age 55) with breast cancer diagnosis without distant metastases (M0). The median value of the tumour diameter was 1.51 cm. The control group consisted of 30 healthy, non-smoking, post-menopausal women, mean age 49, range 44 - 54 years of age. The exclusion criteria for all the participants were hypertension, hyperlipidaemia, and hyperglycaemia, acute and chronic infection. With regard to the fresh blood samples the number of circulating endothelial progenitors was determined using flow cytometry. The fluorescence of 100,000 cells was measured during the analysis. Circulating EPCs were identified with the immune-phenotype CD45-, CD34+, CD133+, CD31+. A significantly higher number of circulating EPCs in the study group, as compared to the controls (P = 0.0001) and a significantly higher number of circulating EPCs in women over 60 with breast cancer than in the younger women (P = 0.0029) were reported. A positive correlation was noted between circulating EPCs and age as well as between circulating EPCs and HER-2 (P = 0.0231, P = 0.0414, respectively), and a negative correlation between circulating EPCs and histological grading of breast cancer (P = 0.0272). The study has shown a higher number of circulating EPCs in breast cancer patients, which indicates stimulation of neovascularization. Additionally, since bone morrow-derived circulating EPCs are more intensively mobilised in older and overweight breast cancer patients, we can speculate that more aggressive neo-angiogenesis can occur in those patients.

Dynamics of hepatitis B virus quasispecies heterogeneity in association with nucleos(t)ide analogue treatment determined by MALDI-TOF MS.

Minor drug-resistant variants may preexist in every subject infected with hepatitis B virus (HBV). However, understanding the dynamic of genotypic evolution within the HBV population requires accurately following allele frequencies through time. We used MALDI-TOF MS (matrix-assisted laser desorption-ionization time-of-flight mass spectrometry) for localization and quantitative allele frequency detection to investigate preexisting HBV quasispecies and the genotypic evolution of drug-resistant variants during nucleos(t)ide analogue therapy. We found a significant difference between the genotypic evolution of drug-resistant variants depending on response to treatment.

The redox status of human breast cancer cell lines (MCF-7 and MDA-MB231) treated with novel dinuclear berenil-platinum(II) complexes.

This study compared the effects of cisplatinum and novel berenil-platinum(ll) complexes on the redox status of breast cancer cells that were estrogen receptor-positive (MCF-7) or estrogen receptor-negative (MDA-MB231). Both cell lines were treated with cisplatinum or the following berenil-platinum(ll) complexes: Pt2(isopropylamine)4(berenil)2, Pt2(piperidine)4(berenil)2, Pt2(2-picoline)4(berenil)2, Pt2(3-picoline)4(berenil)2, and Pt2(4-picoline)4(berenil)2. Changes in levels of reactive oxygen species, levels and activities of antioxidants, and lipid peroxidation products levels were measured. All investigated compounds enhanced ROS generation, reduced the activity of antioxidant enzymes (e.g., glutathione peroxidase and glutathione reductase), and decreased levels of small-molecule antioxidants (GSH, vitamins E and A). Such conditions are conducive to generating oxidative stress and phospholipids peroxidation. Cellular phospholipids in MCF-7 cells were most sensitive to the Pt2(isopropylamine)4(berenil)2 complex, whereas MDA-MB231 cells were not particularly sensitive to any berenil-platinum(ll) complex. These findings will facilitate future anticancer drug design strategy for breast cancer pharmacotherapy.

Effects of dinuclear berenil-platinum(II) complexes on fibroblasts redox status.

PURPOSE: Platinum(II) complex anticarcinogenic mechanisms are associated with changes in the cellular redox status of cancer as well as healthy cells. Therefore, the goal of the present study was to investigate oxidative modifications in cellular components following fibroblast exposure to novel dinuclear berenil-platinum(II) complexes. MATERIAL AND METHOD: ROS levels, antioxidant parameters level/activity, and damage to DNA, lipids, and proteins, including pro-apoptotic and anti-apoptotic factors in human skin fibroblasts following berenil-platinum(II) complex treatments i.e. Pt2(isopropylamine)4(berenil)2, Pt2(piperazine)4(berenil)4, Pt2(2-picoline)4(berenil)2, Pt2(3-picoline)4(berenil)2, and Pt2(4- picoline)4(berenil)2 were examined. RESULTS: Treatment of fibroblasts with platinum(II) complexes has shown that all compounds enhance total ROS and superoxide anion generation as well as change the activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase and decrease in the level of non-enzymatic antioxidants (GSH, vitamin C, E and A). Such a situation is conducive to oxidative stress formation and oxidative modifications of cellular macromolecules and to increase in the expression of proapoptotic proteins. Pt2(isopropylamine)4(berenil)2 elicited the most damage, which resulted in oxidative modification of cellular components. The therapeutic use of this complex would cause considerable side effects in patients, therefore the agent lacks drug potential; however Pt2(piperazine)4(berenil)2 and Pt2(2-picoline)4(berenil)2 exhibited reduced redox and increased apoptotic profiles compared to cisplatin. CONCLUSION: Results of this paper and preliminary data show that Pt2(2-picoline)4(berenil)2 is less dangers than cisplatin to fibroblasts and more disruptive than cisplatin to breast cancer cell metabolism, and therefore it is a promising candidate for use in future anticancer drug strategies.

Hambúrgueres de aparas de jacaré-do-pantanal (Caiman yacare) submetidos a diferentes técnicas de defumação / Hamburguers from pantanal caiman meat (Caiman yacare) subjected to different smoking techniques

Avaliaram-se hambúrgueres de aparas de jacaré-do-pantanal (Caiman yacare) quanto à composição centesimal, cor e análise sensorial. O delineamento foi inteiramente ao acaso, em três tratamentos: T1= sem defumação; T2= defumação a quente e T3= defumação líquida, e nove repetições. As aparas foram moídas e condimentadas para o hambúrguer. Os hambúrgueres para defumação a quente foram colocados no defumador 60 min a 60ºC com gerador de fumaça por fricção. Foi pulverizada fumaça líquida, sobre os produtos (T3), e estes foram colocados em desidratador por 60 min a 60ºC. Houve diferença significativa quanto à composição centesimal entre os hambúrgueres defumados, T2 = 43,1% e T3 = 60,9%, e verificou-se menor teor de umidade em relação aos sem defumação, 73,3%. A proteína, 39,9%, e as cinzas, 6,1%, foram mais altas nos defumados a quente. Os hambúrgueres defumados a quente apresentaram menor luminosidade, 42,05, e maiores valores do croma a*, 14,65, e b*, 28,57, em relação aos demais tratamentos. As variáveis sensoriais foram significativas para sabor, textura e aceitação geral. Os produtos defumados a quente apresentaram a pior aceitação. Concluiu-se que a defumação a quente proporciona produtos com menor teor de umidade, com pigmentação mais intensa, porém menos aceitos pelos provadores.

Hamburgers made from minced meat of Pantanal caiman (Caiman yacare) were evaluated for their centesimal composition, color and sensory perception. The experiment was structured in a completely randomized design with three treatments (T1 = no smoke; T2 = smoked with hot smoke and T3 = smoked with liquid smoke), with nine repetitions each. The meat was minced and seasoned for the hamburgers. The hamburgers destined to hot smoking were placed in the smoker (60 min at 60ºC) with smoke generated through friction. The liquid smoke was sprayed in the samples (T3), next they were placed in dehydrators (60 min at 60ºC). There was a significant difference in centesimal composition, the smoked hamburgers (T2 = 43.1% and T3 = 60.9%) presenting significantly less moisture than non-smoked products (73.3%). Protein (39.9%) and ash (6.1%) were higher for the hot-smoked samples. The hot-smoked hamburgers had less luminosity (42.05) and higher values of chroma a* (14.65) and b* (28.57) than the other treatments. The sensorial parameters evaluated were significant for flavor, texture and general acceptance. The hot-smoked products had the worst acceptance. It was concluded that the hot smoke provided products with less moisture and higher pigmentation, but with less acceptance from the judges.

Coexistence of HFE and rare UGT1A1 genes mutations in patients with iron overload related liver injury.

This report describes two patients hospitalised in Hepatology Unit, Infectious Diseases Department Medical University of Gdansk because of liver damage discovered in family doctor's practice. Hereditary hemochromatosis was diagnosed in both cases. Diagnosis was established basing on medical records review, and biochemical, molecular and liver specimen tests. The analysis of polymorphism of UGT1A1 gene was done in these cases because those patients were a part of the larger study on prevalence of UGT1A1 gene mutations in patients with hereditary hemochromatosis. We discovered rare variant forms of UGT1A1 gene coexisting with HFE gene mutations.

Human DNA topoisomerase inhibitors from Potentilla argentea and their cytotoxic effect against MCF-7.

Two polyphenolics, kaempferol 3-O-beta-D-(6"-E-p-coumaroyl)-glucopyranoside (tiliroside) (1) and methyl brevifolincarboxylate (2) isolated from aerial parts of Potentilla argentea L. (Rosaceae) were evaluated for their cytotoxicities against human breast carcionoma cell line (MCF-7) and their DNA-binding ability. The DNA-binding ability of these compounds was studied by means of the human DNA topoisomerase I and II inhibition assay and ethidium displacement assay using calf thymus DNA, poly(dA-dT)2 and poly(dG-dC)2. Compound 2 was much more active and showed a higher level of cytotoxic potency than compound 1, with IC50 values of 1.11 +/- 2 microM and 21.60 +/- 2 microM, respectively. In DNA topoisomerase I and II inhibition in vitro assays both investigated compounds 1 and 2 were more effective against topoisomerase II than I. The results of DNA binding studies reveal that methyl brevifolincarboxylate had a greater DNA binding affinity that tiliroside, which correlates with its greater potency as a topoisomerase I/II inhibitor.

European multicenter evaluation of high-density DNA probe arrays for detection of hepatitis B virus resistance mutations and identification of genotypes.

Polymorphisms along the hepatitis B virus (HBV) genome have an impact on disease outcome, sensitivity to antiviral treatment, escape from vaccination, and laboratory diagnosis. We have designed a diagnostic tool based on duplex amplification of the whole HBV genome and a high-density DNA chip designed to detect 245 mutations, 20 deletions, and 2 insertions at 151 positions and to determine the genotype of the virus in serum. Assay performances were evaluated with 170 samples, characterized by determination of viral load and sequencing of the Pol, S, and precore genes and the basal core promoter. One hundred fifty-three samples (90%) could be amplified and analyzed by the chip. Only two samples with more than 10(3) genome copies/ml could not be analyzed. Genotype had no impact on analytical sensitivity. Reproducibility studies showed no difference between repeats for codon and genotype determination. Genotype determination by sequencing and the chip were concordant in 148 of 151 samples. Twelve thousand one hundred sixty-one codons were analyzed by both techniques. Only 89.4% could be determined by sequencing, and among the remaining 11,335 codons, 92.8% were identical by sequencing and the chip. Failures to identify an amino acid by the chip were mainly due to reduced hybridization efficiency attributed to unexpected polymorphisms. Optimization of the chip-based reagent for the analysis of the HBV genome is ongoing. This first evaluation showed that DNA chip technology can provide important information in relation to the clinical management of chronic hepatitis B.

Hepatitis delta virus infection in chronically HBV-infected patients from northern Poland.

The objective of this study was to estimate the presence of hepatitis delta virus RNA in chronically HBV-infected patients from northern Poland. Three out of 63 studied samples (4.8%) were positive in a qualitative test for total antibodies to HDV antigen. Five samples (7.9%) turned out to be HDV-RNA-positive by RT-PCR, four of them were sequenced in the region of L-HDAg, and phylogenetic analysis was performed. All four examined samples belonged to genotype I. Two RNA-positive/anti-HD-negative samples possessed a few uncommon nucleotide substitution sites within the L-HDAg sequence, which could suggest unique variants in the Polish population of HDV-infected patients.

An epidermal growth factor receptor intron 1 polymorphism in healthy women in Poland.

The frequency of CA allele combinations was assessed in healthy women from Poland and compared to previously published polymorphism data of individuals from Germany and a Caucasian reference group. There were close similarities between these three geographically and ethnically similar populations. By contrast, the distribution of these alleles in European and Asian (Japan) populations proved to be different. There might therefore be major ethnic differences in allelic frequencies of EGFR intron 1 polymorphism. Our results provide new data on EGFR microsatellite instability and may contribute to the understanding of EGFR gene expression regulation. The clinical relevance of these findings warrants further evaluation.

The diverse signaling network of EGFR, HER2, HER3 and HER4 tyrosine kinase receptors and the consequences for therapeutic approaches.

The HER family of receptor tyrosine kinase couples binding of extracellular growth factor ligands to intracellular signal transduction pathways, contributing in this fashion to the ability of the cell to respond correctly to its environment. The HER family and its ligands are critically involved in the carcinogenesis of the mammary gland. Abnormal function of the members of HER family resulting in receptor hyper-activation (due to gene amplification, protein overexpression or abnormal transcriptional regulation) has been linked with breast cancer prognosis. It is also extensively studied as the predictive factor and target for therapy. There are clinical indications supporting the concept that none of the receptors: EGFR, HER2, HER3 and HER4 can be considered as the stand-alone receptor in breast cancer development and clinical course of the disease. There is a growing body of evidence that cooperation between them contributes to more aggressive tumor phenotype and influences the response to therapy. This underlines the importance of quantification of all HER family members and indicates the urgent need for implementation of methods that can efficiently and reliably examine four HER receptors as a whole panel in breast cancer patients.

An epidermal growth factor receptor intron 1 polymorphism in healthy women in Poland.

The frequency of CA allele combinations was assessed in healthy women from Poland and compared to previously published polymorphism data of individuals from Germany and a Caucasian reference group. There were close similarities between these three geographically and ethnically similar populations. By contrast, the distribution of these alleles in European and Asian (Japan) populations proved to be different. There might therefore be major ethnic differences in allelic frequencies of EGFR intron 1 polymorphism. Our results provide new data on EGFR microsatellite instability and may contribute to the understanding of EGFR gene expression regulation. The clinical relevance of these findings warrants further evaluation. (Int J Biol Markers 2005; 20: 184-8).

p53 Gene status in relation to ex vivo chemosensitivity of non-small cell lung cancer.

PURPOSE: About 40% of non-small cell lung cancer (NSCLC) patients are candidates for systemic chemotherapy, despite the fact that at diagnosis most NSCLC are usually chemoresistant both in vivo and ex vivo. It is important to develop sufficient methods of prediction of the response to chemotherapy and to find molecular markers that may prognose this response. Therefore, a study on the relationship of p53gene status to the ex vivo chemosensitivity of primary human NSCLC was performed. METHODS: Three drug combinations (carboplatin/etoposide, cyclophosphamide/etoposide/epirubicin, and paclitaxel/carboplatin) were tested in a modified ATP cell viability assay. A group of 28 cases of primary human NSCLC was assessed. RESULTS: Ex vivo chemosensitivity testing showed that tumors with p53 mutations were significantly more resistant to the cyclophosphamide/etoposide/epirubicin regimen than with normal p53 gene ( P = 0.012). However, no correlation was observed for two other treatment regimens. CONCLUSION: Mutations in the p53gene can lead to enhanced chemoresistance, confirming the hypothesis that the p53 gene may serve as a marker of tumor response to treatment in NSCLC. However, the data also illustrate that some additional factors might contribute to drug resistance of the examined tumors.

Cytotoxicity and effect on collagen biosynthesis of proline analogue of melphalan as a prolidase-convertible prodrug in cultured human skin fibroblasts.

Proline analogue of melphalan (MEL-PRO) was synthesised as a prodrug susceptible to the action of ubiquitously distributed, cytosolic imidodipeptidase--prolidase [E.C.3.4.13.9]. Conjugation of melphalan (MEL) with proline (PRO) through an imido-bond resulted in formation of a good substrate for prolidase. The susceptibility of MEL-PRO to the action of prolidase was found to be similar, compared to glycyl-proline--the most abundant, endogenous substrate for prolidase and about 6-fold higher compared to its substrate--glycyl-hydroxyproline. We have compared the transport of MEL and its prodrug through cell membrane, their antimitotic activity, cytotoxicity and effect on collagen biosynthesis in cultured, normal human skin fibroblasts. The prodrug was found to be more effectively transported into the cells than the free drug. Moreover, a lower cytotoxicity, antimitotic activity and inhibitory effect on collagen biosynthesis of the prodrug, compared to the free drug were observed after 24 h of incubation. MEL and MEL-PRO at concentrations of 12 microM led to the decrease in cell viability in confluent human skin fibroblasts by about 40 and 20%, respectively, during 24 h of incubation. IC50 of MEL for DNA synthesis (measured by thymidine incorporation assay) was found at about 7 microM, while MEL-PRO used at this concentration produced about 35% reduction in thymidine incorporation. Similarly, MEL and MEL-PRO used at 7 microM concentrations inhibited collagen biosynthesis in fibroblasts cultured for 24 h to about 30 and 80% of control values, respectively. However, when the cells were cultured with the drugs for 72 h, similar effects of both drugs on DNA and collagen biosynthesis were observed. The data suggest that MEL-PRO may serve as a prolidase-convertible prodrug that evokes lower cytotoxicity, antimitotic activity, and lower inhibitory effect on collagen biosynthesis in fibroblast cultures, compared to the free drug.

The suitability of DNA extracted from formalin-fixed, paraffin-embedded tissues for double differential polymerase chain reaction analysis.

Formalin-fixed, paraffin-embedded (FFPE) tissues are one of the popular sources of diagnostic materials, the easiest to store and transport. They are often used as the source of nucleic acids for retrospective molecular analyses based on DNA amplification by polymerase chain reaction (PCR). However, it is known that nucleic acids from paraffin-embedded tissues are much worse templates than those recovered from fresh tissues. It is exceptionally important in a quantitative analysis, including double differential PCR (ddPCR). Therefore, a pilot study comparing quantity and quality of DNA extracted with various paraffin removal and DNA isolation procedures from FFPE tissues was conducted. Furthermore, the suitability of DNA isolated with optimized procedure for the assessment of erbB-2 average gene copy number (AGCN) was checked. Specimens for comparison of extraction and isolation procedures were generated from the same human normal thyroid tissue embedded in paraffin to eliminate variabilities in tissue processing and sample size. Three procedures of paraffin removal and three procedures of DNA extraction from deparaffinized tissue were compared. Only one procedure provided DNA, which was efficiently amplified in ddPCR. The material obtained with this optimized procedure was used to check the precision of ddPCR by evaluation of AGCN of erbB-2 oncogene. Low variability of obtained results close to expected AGCN value (AGCN=1) indicates high reproducibility of the method, as well as its high accuracy, if the normal value of erbB-2 AGCN in the examined tissue is assumed.