Biomedical subjects

Marek Foksinski

Publications and source records attributed to Marek Foksinski.

11 recordsLinked to original sources

PubMed2007

Oxidative damage to DNA and antioxidant status in aging and age-related diseases.

Aging is a complex process involving morphologic and biochemical changes in single cells and in the whole organism. One of the most popular explanations of how aging occurs at the molecular level is the oxidative stress hypothesis. Oxidative stress leads in many cases to an age-dependent increase in the cellular level of oxidatively modified macromolecules including DNA, and it is this increase which has been linked to various pathological conditions, such as aging, carcinogenesis, neurodegenerative and cardiovascular diseases. It is, however, possible that a number of short-comings associated with gaps in our knowledge may be responsible for the failure to produce definite results when applied to understanding the role of DNA damage in aging and age-related diseases.

Adolescent↗

PubMed2006

Severe oxidatively damaged DNA after cisplatin treatment of cancer patients.

There is growing evidence suggesting that cytotoxic activity of cisplatin is closely associated with increased generation of reactive oxygen species (ROS). Therefore, this study was undertaken to examine oxidative DNA damage, which arises as a result of chemotherapy with cisplatin. Using HPLC prepurification/isotope dilution GC/MS methodology, we examined the amount of 8-oxoGua and 8-oxodG excreted into urine in cancer patients (n = 66) who received chemotherapy with cisplatin. One day after the infusion of the drug, significant increase in the amount of 8-oxoGua and 8-oxodG in urine of the patients was observed, when compared to the initial value (78%, p < 0.0001 and 22%, p = 0.0051). In the "nadir days" (when the most distinct cell death based on hematological cell counts can be observed), the level of modified base and nucleoside decreased in comparison with the aforementioned time point. These results, for the first time, indicate that oxidatively damaged DNA may be, at least in part, responsible for cisplatin induced cytotoxicity. Our results also demonstrate that cell death does not contribute to urinary 8-oxoGua and 8-oxodG in humans.

Antineoplastic Agents↗

PubMed2005

Substantial decrease of urinary 8-oxo-7,8-dihydroguanine, a product of the base excision repair pathway, in DNA glycosylase defective mice.

Genome integrity is maintained via removal (repair) of DNA lesions and an increased load of such DNA damage has been linked to numerous pathological conditions, including carcinogenesis and ageing. 8-Oxo-7,8-dihydroguanine is one of the most critical lesions of this type. The free 8-oxo-7,8-dihydroguanine produced by the action of a specific DNA glycosylase is a potential source of this compound in urine. To date, there has been no direct, experimental evidence demonstrating that urinary 8-oxo-7,8-dihydroguanine is produced by the base excision repair pathway. For clarification of this issue, we applied a recently developed methodology which involved high performance liquid chromatography pre-purification followed by gas chromatography with isotope dilution mass spectrometric detection to compare the urinary excretion rate of 8-oxo-7,8-dihydroguanine in wild type and OGG1 glycosylase knock out mice. Our study revealed a 26% reduction in urinary level of 8-oxo-7,8-dihydroguanine in OGG1 deficient mice in comparison with the wild type strain. This clearly indicates that the mouse OGG1 glycosylase contributes significantly to the generation of urinary 8-oxo-7,8-dihydroguanine. Therefore, urinary measurements of 8-oxo-7,8-dihydroguanine may be attributed to DNA damage and repair, which in turn suggests that they may be useful in studying associations between DNA repair and disease.

Animals↗

PubMed2004

Urinary excretion of DNA repair products correlates with metabolic rates as well as with maximum life spans of different mammalian species.

Using recently developed methodology, which includes HPLC prepurification followed by GC/MS with isotope dilution, we analyzed urinary excretion of possible repair products of oxidative DNA damage-8-oxo-7,8-dihydroguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and 5-(hydroxymethyl)uracil (5-HMUra)-in mammalian species that substantially differ in metabolic rate and longevity, namely, mice, rats, rabbits, dogs, pigs, and humans. We found highly significant, positive correlations between specific metabolic rates of the animals studied and their excretion rates for all the modifications analyzed with respective r values for the lesions of (8-oxoGua) r = .891, p < .01; (8-oxodG) r = .998, p < .001; and (5-HMUra) r = .949, p < .005. However, only 8-oxoGua significantly correlates negatively with maximum life span (MLSP) (r = -.928, p < .01). Despite substantial differences in MLSP between humans and pigs (120 and 27 years, respectively), the rates of excretion of all measured modifications were very similar. The urinary levels of all measured modifications found in our study for mouse and humans account respectively for about 34,000 and 2800 repaired events per average cell, per 24 h. It is therefore possible that the high metabolic rate in mice (or other short-lived animals) may be responsible for severe everyday oxidative DNA insults that may be accumulated faster than in long-lived species.

Animals↗

PubMed2004

Diet is not responsible for the presence of several oxidatively damaged DNA lesions in mouse urine.

In order to eliminate the possibility that diet may influence urinary oxidative DNA lesion levels, in our experiments we used a recently developed technique involving HPLC pre-purification followed by gas chromatography with isotope dilution mass spectrometric detection. This methodology was applied for the determination of the lesions: 8-oxo-7,8-dihydroguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and 5-(hydroxymethyl)uracil (5HMUra) in the urine of mice fed with nucleic acid free diet and normal, unrestricted diet. The mean levels of 8-oxoGua, 8-oxodGuo and 5HMUra of the animals fed the normal diet reached the mean values of 15.6 +/- 3.5, 2.0 +/- 0.53 and 16.8 +/- 10.4 nmol/kg/24 h, After feeding the mice for 12 days with nucleic acid free diet the respective values were 18.8 +/- 4.6, 1.6 +/- 0.3 and 25.4 +/- 10.5 nmol/kg/24 h, respectively. The results clearly demonstrate that irrespective of the diet, the excretion rates were not statistically different during the course of feeding. The respective p values for the differences between lesions in the two types of diets were: 0.13 (8-oxoGua), 0.16 (8-oxodGuo), 0.18 (5-HMUra). Our results clearly indicate that diet does not contribute to urinary excretion of the lesions in mouse model.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2004

Androgen receptor versus erbB-1 and erbB-2 expression in human prostate neoplasms.

A subject of current interest, especially in the development of androgen refractory prostate cancer, is the androgen receptor (AR) activation by growth factor receptors. Here, we report our work on the measurement of AR mRNA and protein expression in benign prostatic hyperplasia (BPH) and prostatic carcinoma (PCA) and evaluation of the relationship between AR, erbB-1 and erbB-2 gene expression determined in the same tissue. In order to define AR, erbB-1 and erbB-2 in human prostate neoplasms 36 benign prostatic hyperplasia, 46 prostatic carcinoma and 12 normal prostate gland samples were analysed. According to distant metastasis PCA tissues were divided into two categories: i) T1-4N0-3M0 (25 samples) and ii) T4N2-3M1 (21 samples). AR, erbB-1 and erbB-2 mRNA expression was estimated by RT-PCR. AR protein expression, both in nuclear and cytoplasmic fractions, was measured by Western blot technique. The association of AR mRNA and protein expression with erbB-1 and erbB-2 gene expression was evaluated. It was found that in clinically invasive (group II of PCA) prostate cancer cases AR mRNA expression was significantly correlated with erbB-2 mRNA expression (Spearman R coefficient 0.86, p<0.05). Interestingly, AR protein expression in this group of PCA was determined mainly in nuclear fraction. By Western blot AR protein was identified in 76.0% (16/21) and 23.8% (5/21) of PCA group II nuclear and cytoplasmic fractions, respectively. Furthermore, the mean AR protein level in nuclear fraction of clinically invasive (group II) PCA (0.82+/-0.04) was significantly higher (p<0.05) as compared to the normal group (0.56+/-0.11). In the case of T4N2-3M1 samples, significant correlation between AR protein level in nuclear fraction and erbB-2 mRNA expression (Spearman R coefficient 0.53, p<0.05) was stated.

Adult↗

PubMed2003

Oxidative DNA damage in cancer patients: a cause or a consequence of the disease development?

A wide variety of oxidative DNA lesions are present in living cells. One of the best known lesions of this type is 8-oxoguanine (8-oxoGua) which has been shown to have mutagenic properties. An influence of antioxidative vitamins and labile iron pool on the background level of 8-oxoGua in cellular DNA is discussed and oxidative damage to free nucleotide pool as a possible source of 8-oxo-2'-deoxyguanosine in DNA and urine is described. An involvement of 8-oxoGua in the origin and/or progression of cancer is reviewed. It is concluded that a severe oxidative stress manifested as a high level of 8-oxoGua in cellular DNA as well as in urine of cancer patients is a consequence of development of many types of cancer. Although at present it is impossible to answer directly the question concerning involvement of oxidative DNA damage in cancer etiology it is likely that oxidative DNA base modifications may serve as a source of mutations that initiate carcinogenesis (i.e. they may be causal factors responsible for the process).

Carcinogens↗

PubMed2003

Cellular level of 8-oxo-2'-deoxyguanosine in DNA does not correlate with urinary excretion of the modified base/nucleoside.

We assessed a relationship between the level of 8-oxodG in leukocyte DNA measured with the high performance liquid chromatography with electrochemical detection (HPLC/EC) technique and urinary excretion of the modified nucleoside/base analysed with a recently developed methodology involving HPLC prepurification followed by gas chromatography with isotope dilution mass spectrometric detection. No correlation was found between these markers of oxidative DNA damage commonly used in epidemiological studies. Several possible explanations of this finding are discussed.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2002

Oxidative DNA damage: assessment of the role in carcinogenesis, atherosclerosis, and acquired immunodeficiency syndrome.

Free radical attack upon DNA generates a multiplicity of DNA damage, including modified bases. Some of these modifications have considerable potential to damage the integrity of the genome. This article reviews recent data that suggest the involvement of oxidative DNA damage in carcinogenesis, atherosclerosis, and acquired immunodeficiency syndrome (AIDS). There is evidence that oxidative DNA damage may play a causative role in atherosclerosis. Oxidative DNA damage may lead to apoptotic cell death of patients infected with human immunodeficiency virus (HIV) and may influence the progression of AIDS. While many details regarding the role of reactive oxygen species-induced DNA damage in the etiology of complex multifactorial diseases like cancer are yet to be discovered, evidence suggests that oxidants act at several stages in the malignant transformation of cells. However, the quantitative relationship between the measured DNA damage and the development of cancer is still lacking.

Acquired Immunodeficiency Syndrome↗

PubMed2002

The level of 8-hydroxyguanine, a possible repair product of oxidative DNA damage, is higher in urine of cancer patients than in control subjects.

Using high-performance liquid chromatography prepurification/isotope dilution gas chromatography/mass spectrometry technique, we examined whether the amount of 8-hydroxyguanine and 8-hydroxy-2'-deoxyguanosine excreted into urine is higher in cancer patients with advanced-stage disease than in the control group. The control group consisted of 38 healthy subjects, and the patient group comprised 42 cancer patients suffering from metastasis of their primary tumors into the bones. We have found that the amount of the modified base (but not the nucleoside) excreted into urine is about 50% higher in cancer patients than in the control group. Because the presence of the modified base in urine may represent the primary repair product of oxidative DNA damage in vivo, our results suggest an important role of DNA glycosylases (most likely OGG1) in removal of the damage induced as a result of cancer development.

Biomarkers, Tumor↗

PubMedDate not supplied

Urinary measurement of 8-OxodG, 8-OxoGua, and 5HMUra: a noninvasive assessment of oxidative damage to DNA.

Numerous DNA repair pathways exist to prevent the persistence of damage, and are integral to the maintenance of genome stability, and hence prevention of disease. Excised lesions arising from repair may ultimately appear in the urine where their measurement has been acknowledged to be reflective of overall oxidative stress. The development of reliable assays to measure urinary DNA lesions, such as HPLC prepurification followed by gas chromatography/mass spectrometry, offers the potential to assess whole body oxidative DNA damage. However, some studies suggest a possibility that confounding factors may contribute to urinary levels of 7,8-dihydro-8-oxoguanine (8-oxoGua) and 7,8-dihydro-8-oxo-2 -deoxyguanosine (8-oxodG). This article considers several possible sources of urinary lesions: (a) the repair of oxidatively damaged DNA; (b) a possible dietary influence; and (c) cell death. The authors conclude that data from their laboratories, along with a number of literature reports, form an argument against a contribution from cell death and diet. In the absence of these confounding factors, urinary measurements may be attributed entirely to the repair of DNA damage and suggests their possible use in studying associations between DNA repair and disease.

8-Hydroxy-2'-Deoxyguanosine↗