Magdalena Brys

Expression of GLUT1 and GLUT3 Glucose Transporters in Endometrial and Breast Cancers

Cancer cells have accelerated metabolism and high glucose requirements. The up-regulation of specific glucose transporters may represent a key mechanism by which malignant cells may achieve increased glucose uptake to support the high rate of glycolysis. In present study we analyzed the mRNA and protein expression of GLUT1 and GLUT3 glucose transporters by quantitative real-time polymerase chain reaction (Q-PCR) and Western blotting technique in 76 cases of endometrial carcinoma and 70 cases of breast carcinoma. SLC2A1 and SLCA2A3 mRNAs expression was found, respectively in 100% and 97.4% samples of endometrial cancers and only in 50% and 40% samples of breast cancers. In endometrial cancers GLUT1 and GLUT3 protein expression was identified in 67.1% and 30.3% of cases. Analogously, in breast cancers in 48.7% and 21% of samples, respectively. The results showed that both endometrial and breast poorly differentiated tumors (grade 2 and 3) had significantly higher GLUT1 and GLUT3 expression than well-differentiated tumors (grade 1). Statistically significant association was found between SLCA2A3 mRNA expression and estrogen and progesterone receptors status in breast cancers. GLUT1 has been reported to be involved in the uptake of glucose by endometrial and breast carcinoma cells earlier and the present study determined that GLUT3 expression is also involved. GLUT1 and GLUT3 seem to be important markers in endometrial and breast tumors differentiation.

Zinc and cadmium analysis in human prostate neoplasms

The objective of this study was to test the hypothesis that prostatic cancer is associated with the changes of zinc (Zn) and cadmium (Cd) concentration. Normal prostate, benign prostatic hyperplasia (BPH), and prostatic carcinoma (PCA) were analyzed for Zn and Cd by atomic absorption spectrometry. Cd level was measured using a graphite furnace and Zn level was measured by flame mode. Metal content was assessed in whole tissues and in nuclear, plasma membrane, and cytosolic fractions. An increase of Zn content in BPH, but a decrease in PCA as compared to normal tissue, was observed. Cd concentration appeared to be higher in BPH and PCA than in normal tissue. No correlation between Zn and Cd level was found in BPH specimens obtained from the same patients. Probability values ofp ≤0.05 were considered to indicate significant differences. Obtained results seem to support the hypothesis of Cd carcinogenicity and preventing function of Zn in prostatic cancer. Plasma membrane fraction corresponding to lysosomal, mitochondrial, and microsomal subcellular compartments are probably critical in Zn and Cd participation in human prostate neoplasms.

Expression of TGF-β type I and II receptors in normal and cancerous human endometrium

Transforming growth factor-beta (TGF-beta) belongs to a superfamily of structurally related polypeptides involved in various biological processes, including cell growth, proliferation and differentiation, angiogenesis, apoptosis, and extracellular matrix remodeling. We tried to define the different expression patterns of the TGF-beta receptors by investigating the female reproductive organs during the menstrual cycle and endometrial tumorigenesis, because their role in these processes is still unclear. In this study, we examined the expression of the TGF-beta type I and type II receptors in normal (n=13) and carcinomatous (n=42) endometrial tissue specimens using reverse transcriptase polymerase chain reaction and immunological (Western blot and enzyme linked immunosorbent assay) methods. Two uncommon female genital tract tumors, rhabdomyosarcoma of the uterine cervix and uterine carcinosarcoma, were also included. There were no significant differences between normal and cancerous endometrial tissues regarding the TGF-beta receptors mRNA levels. However, we observed a markedly low TGF-beta type I receptor protein level (P<0.028; Mann-Whitney-U test), while the malignant endometrium showed a significantly higher TGF-beta type II receptor protein level (P<0.007; Mann-Whitney-U test) than the normal endometrium. Moreover, significantly elevated TGF-beta receptor type II protein level was noted when depth of myometrial invasion of endometrial carcinomas was considered (P<0.05; Mann-Whitney-U test). In contrast to uterine carcinosarcoma, in which no detectable mRNA for TGF-beta type II receptor was found, we noted expression of both TGF-beta receptors in rhabdomyosarcoma of the uterine cervix. However, neither rhabdomyosarcoma of the uterine cervix nor uterine carcinosarcoma displayed TGFbetaRI and TGFbetaRII protein expression. This observation corroborates the complexity of the deregulation of TGF-beta receptor expression in human endometrial cancer.

Metallothionein 2A genetic polymorphisms and risk of prostate cancer in a Polish population

Metallothionein 2A (MT2A) is the most expressed metallothionein (MT) isoform in prostate cells. A number of studies have demonstrated altered MT2A expression in various human tumors, including prostate cancer. We conducted an association study to examine whether MT2A gene polymorphisms are associated with a risk of prostate cancer. Genotyping was conducted using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Three single nucleotide polymorphisms (SNPs), rs28366003, rs1610216, and rs10636, were genotyped in 358 prostate cancer cases and 406 population controls. One SNP in MT2A (rs28366003) showed a positive association with prostate cancer. Compared to homozygous common allele carriers, heterozygosity for the G variant (odds ratio (OR)=2.30, 95% confidence interval (CI): 1.50-3.47, P-trend<0.0001; the OR assuming a dominant model 2.43 (95% CI: 1.62-3.61, P(dominant)=0.001) after adjustment for age) had a significantly increased risk of prostate cancer in a Polish population. Our data suggest that the rs28366003 SNP in MT2A is associated with the risk of prostate cancer in a Polish population.

TopBP1 in DNA Damage Response

DNA, the genetic material of cells, is constantly exposed to a range of endogenous and environmental damaging agents (Jungmichel & Stucki, 2010). DNA molecule is the target of endogenous cellular metabolites such as reactive oxygen species (ROS) (Ciccia & Elledge, 2010; Poehlmann & Roessner, 2010). ROS may cause different alterations in a genome, e.g. simple DNA mutations, DNA single and double strand breaks (SSBs and DSBs, respectively), or more complex changes, including deletions, translocations and fusions (Poehlmann & Roessner, 2010). Alterations may be generated spontaneously due to dNTP misincorporation during DNA replication, interconversion between DNA bases caused by deamination, loss of DNA bases following DNA depurination or depyrimidination and modification of DNA bases by alkylation. Hydrolytic deamination (loss of an amino group) can directly convert one base to another. For example, deamination of cytosine results in uracil and with much lower frequency converts adenine to hypoxanthine. In depurination or depyrimidination, purine or pyrimidine bases are completely removed, leaving deoxyribose sugar depurinated or depyrimidinated that may cause breakage in the DNA backbone (Ciccia & Elledge, 2010; Rastogi et al., 2010). Altogether, it has been estimated that every cell could experience up to 105 spontaneous DNA lesions per day (Ciccia & Elledge, 2010). Environmental DNA damage can be produced by physical or chemical sources, such as ionizing radiation (IR), ultraviolet (UV) light from sunlight and organic and inorganic chemical substances (Muniandy et al., 2010; Rastogi et al., 2010; Su et al., 2010). Exposure to ionizing radiation from, e.g. cosmic radiation and medical treatments employing X-rays or radiotherapy inflicts DNA single and double strand breaks, oxidation of DNA bases and DNA-protein crosslinks in the genomic DNA (Ciccia & Elledge, 2010; Su et al., 2010). Ionizing radiation provokes DNA damage directly by energy deposit on the DNA double helix and indirectly by reactive oxygen/nitrogen species (ROS/RNS) (Corre et al., 2010). Ultraviolet radiation (mainly UV-B) is a powerful agent that may lead to the formation of three major classes of DNA lesions, such as cyclobutane pyrimidine dimmers (CPDs), pyrimidine 6-4 pyrimidone photoproducts (6-4 PPs) and their Devar isomers (Rastogi et al., 2010). Cells may become transiently exposed to external sources of DNA damage, such as cigarette smoke or various toxic chemical compounds (Jungmichel & Stucki, 2010). Many antineoplastic drugs currently used in cancer treatment express their cytotoxic effects through their ability to directly or indirectly damage DNA and thus resulting in cell death. Major types of DNA damage induced by anticancer treatment include single and double strand breaks, interstrand, intrastrand and DNA-protein crosslinks, as well as interference

Dinucleotide repeat polymorphisms of RAD51, BRCA1, BRCA2 gene regions in breast cancer.

Recent studies suggest that genetic polymorphisms of the DNA repair genes have been implicated in breast cancer risk. BRCA1 and BRCA2, two breast cancer susceptibility genes, are essential to maintain chromosomal integrity. This is mediated via regulation of RAD51 during homologous recombination. Dinucleotide polymorphism repeats in the 15q14–21, 17q21 and 13q12–13 regions, where the RAD51, BRCA1 and BRCA2 genes are located, respectively, have been evaluated. The polymorphism was determined using the following microsatellite markers: D15S118, D15S214, D15S1006, D17S855, D17S1323, D13S260 and D13S290. Genotypes containing the (CA)17 or (CA)19 alleles in the RAD51 region were found to be associated with a decreased breast cancer risk. Genotype containing the (CA)17 allele in the 13q12–13 region was found to be associated with an increased breast cancer risk. The results indicate that dinucleotide CA repeat polymorphism at RAD51 and BRCA2 gene regions might be associated with genetic susceptibility to breast cancer.

Why a Combination of WP 631 and Epo B is an Improvement on the Drugs Singly - Involvement in the Cell Cycle and Mitotic Slippage

Our previous studies clearly demonstrated that a combination of WP 631 and Epo B has higher activity against ovarian cancer cells than either of these compounds used separately. In order to fully understand the exact mechanism of action in combination, we assessed effects on the cell cycle of SKOV-3 cells. We evaluated three control points essential for WP 631 and Epo B action to determine which cell cycle-regulating proteins (CDK1/cyclin B complex, EpCAM or HMGB1) mediate activity. The effects of the drug on the cell cycle were measured based on the nuclear DNA content using flow cytometry. Expression of cell cycle-regulating genes was analyzed using real-time PCR. It was discovered that WP 631, at the tested concentration, did not affect the SKOV-3 cell cycle. Epo B caused significant G2/M arrest, whereas the drug combination induced stronger apoptosis and lower mitotic arrest than Epo B alone. This is very important information from the point of view of the fight against cancer, as, while mitotic arrest in Epo B-treated cells could be overcame after DNA damage repair, apoptosis which occurs after mitotic slippage in combination-treated cells is irreversible. It clearly explains the higher activity of the drug combination in comparison to Epo B alone. Epo B acts via the CDK1/cyclin B complex and has the ability to inhibit CDK1, which may be a promising strategy for ovarian cancer treatment in the future. The drug combination diminishes EpCAM and HMGB1 expression to a greater degree than either WP 631 and Epo B alone. Owing to the fact that the high expression of these two proteins is a poor prognostic factor for ovarian cancer, a decrease in their expression, observed in our studies, may result in improved efficacy of cancer therapy. The presented findings show that the combination of WP 631 and Epo B is a better therapeutic option than either of these drugs alone.

Expression of Vascular Endothelial Growth Factor (VEGF) and its Correlation with Clinical Symptoms and Endoscopic Findings in Patients with Chronic Radiation Proctitis

The aim of this study was to assess the expression of vascular endothelial growth factor (VEGF) as a key proangiogenic factor and determine whether there is any correlation between its expression and clinical symptoms or endoscopic changes in patients with chronic radiation proctitis (ChRP).