The aim of this study was to evaluate hypoxia level at various tumor developmental stages and to compare various methods of hypoxia evaluation in pre-clinical CT26 tumor model. Using three methods of Show more
The aim of this study was to evaluate hypoxia level at various tumor developmental stages and to compare various methods of hypoxia evaluation in pre-clinical CT26 tumor model. Using three methods of hypoxia determination, we evaluated hypoxia levels during CT26 tumor development in BALB/c mice from day 4 till day 19, in 2-3 days intervals. Molecular method was based on the analysis of selected genes expression related to hypoxia (HIF1A, ANGPTL4, TGFB1, VEGFA, ERBB3, CA9) or specific for inflammation in hypoxic sites (CCL2, CCL5) at various time points after CT26 cancer cells inoculation. Imaging methods of hypoxia evaluation included: positron-emission tomography (PET) imaging using [18F]fluoromisonidazole ([18F]FMISO) and a fluorescence microscope imaging of pimonidazole (PIMO)-positive tumor areas at various time points. Our results showed that tumor hypoxia at molecular level was relatively high at early stage of tumor development as reflected by initially high HIF1A and VEGFA expression levels and their subsequent decrease. However, imaging methods (both PET and fluorescence microscopy) showed that hypoxia increased till day 14 of tumor development. Additionally, necrotic regions dominated the tumor tissue at later stages of development, decreasing the number of hypoxic areas and completely eliminating normoxic regions (observed by PET). These results showed that molecular methods of hypoxia determination are more sensitive to show changes undergoing at cellular level, however in order to measure and visualize hypoxia in the whole organ, especially at later stages of tumor development, PET is the preferred tool. Furthermore we concluded, that during development of tumor, two peaks of hypoxia occur. Show less
Canine mammary sarcomas are usually very aggressive and easily metastasize. Unfortunately the biology of this type of tumor is not well known because they are a very rare type of tumors. The aim of th Show more
Canine mammary sarcomas are usually very aggressive and easily metastasize. Unfortunately the biology of this type of tumor is not well known because they are a very rare type of tumors. The aim of this study was to find differences in gene expression patterns in canine mammary osteosarcomas (malignant) versus osteomas (benign) using DNA microarrays. Our microarray experiment showed that 11 genes were up-regulated in osteosarcoma in comparison to osteoma whereas 36 genes were down-regulated. Among the up-regulated genes were: PDK1, EXT1, and EIF4H which are involved in AKT/PI3K and GLI/Hedgehog pathways. These genes play an important role in cell biology (cancer cell proliferation) and may be essential in osteosarcoma formation and development. Analyzing the down-regulated genes, the most interesting seemed to be HSPB8 and SEPP1. HSPB8 is a small heat shock protein that plays an important role in cell cycle regulation, apoptosis, and breast carcinogenesis. Also SEPP1 may play a role in carcinogenesis, as its down-regulation may induce oxidative stress possibly resulting in carcinogenesis. The preliminary results of the present study indicate that the up-regulation of three genes EXT1, EIF4H, and PDK1 may play an essential role in osteosarcoma formation, development and proliferation. In our opinion the cross-talk between GLI/Hedgehog and PI3K/AKT pathways may be a key factor to increase tumor proliferation and malignancy. Show less
The aim of this work was the assessment of the clinical condition, birth weight, frequency of premature birth and incidence of intrauterine growth restriction (IUGR) of the newborns whose mothers were Show more
The aim of this work was the assessment of the clinical condition, birth weight, frequency of premature birth and incidence of intrauterine growth restriction (IUGR) of the newborns whose mothers were active and passive smokers. This was a prospective study conducted in a group of 147 newborns born during the years 2003-2004 in the Princess Anna Mazowiecka Hospital, Warsaw, and hospitalized in the Neonatal and Intensive Care Department of Warsaw Medical University. Based on a questionnaire identifying the exposure to tobacco smoke and cotinine concentration in the mother's urine, the newborns were assigned to three groups: the newborns whose mothers were active smokers, the newborns whose mothers were passive smokers and the newborns of non-smoking mothers. There were no statistically significant differences in the Apgar score assessment at the 1st and 5th minute between the three groups of the newborns. Acid-base balance parameters (pH, BE) were also similar. The birth weight of the newborns of mothers who were active smokers was 325g lower than the birth weight of the newborns of non-smoking mothers. This difference was statistically significant p = 0.033. Maternal smoking in pregnancy was associated with an increased risk of deficit in birth weight 2.6 (1.0-6.9, CI 95%). In the group of the newborns whose mothers were active smokers, the incidence of lower birth weight (< 2500g) was also statistically significantly higher p = 0.01. There were no statistically significant differences in the incidence of premature birth and intrauterine growth restriction (IUGR). Show less