Increased spontaneous and mitomycin C-induced sister chromatid exchanges in patients with cancer of the cervix uteri, with special reference to stage of cancer

Frequency of sister chromatid exchanges in the lymphocytes of patients with atopic dermatitis

The combination of genetic susceptibility and environmental factors can induce allergic sensitization and subsequent local inflammation, resulting in atopic dermatitis (AD). Sister chromatid exchange (SCE) is a sensitive method that may reflect an instability in DNA or a deficiency in DNA repair. The aim of the present study was to investigate whether patients with AD have defects in DNA repair and whether SCE frequency can be used as a genetic marker in the pathogenesis of AD. Between September 2004 and July 2005, SCE was analyzed in the peripheral blood lymphocyte chromosomes of 32 patients with AD and 28 control subjects at the Dermatology Unit of Erzurum State Hospital. This study found that the SCE frequency was significantly increased in patients with AD (P < 0.00001). The prevalence of SCE was not correlated with patient age, sex, disease duration or AD disease severity. Our results indicate that increased chromosome instability may play an important role in the etiology of AD.

The role of triple therapy, age, gender and smoking on the genotoxic effects of Helicobacter pylori infection

The role of age, gender and smoking on both the genotoxic effects of Helicobacter pylori and the efficacy of eradication therapy in a group of patients with gastritis was investigated. Gastritis was confirmed by endoscopy and biopsy, and the presence of H. pylori by urease testing. Pre- and post-treatment peripheral blood lymphocyte cultures were prepared from 17 patients and 25 metaphases per patients were analysed for sister chromatid exchange (SCE), a well-established technique for the evaluation of human exposure to toxic agents. Treatment with omeprazole, clarithromycin and amoxycillin triple therapy eradicated H. pylori in 94% of patients and significantly reduced the SCE frequency. Pre-treatment SCE frequency was found to be positively correlated with age. Female smokers tended to have higher post-treatment SCE frequencies than male smokers, and pre- and post-treatment SCE frequencies were higher in older males than in older females. Eradication therapy decreased the genotoxicity of H. pylori, but age in males and smoking in females may decrease treatment efficacy.

Sister chromatid exchanges in peripheral lymphocytes from women with carcinoma of the uterine cervix

Sister chromatid exchanges (SCE) are reciprocal exchanges between sister chromatids. It has been reported that in patients with cervical cancer, the frequency of SCE in peripheral lymphocytes is significantly higher than that in normal individuals; however, other studies have shown no significant difference. The aim of this unmatched case-control study was to compare the mean number of SCE per metaphase in lymphocytes from women with and without carcinoma of the cervix uteri. The SCE specimens were prepared by the fluorescence plus giemsa technique in peripheral lymphocytes from 28 women with carcinoma of cervix uteri and 28 controls. The mean number of SCE per metaphase in women with carcinoma of cervix uteri (7.80 +/- 1.05) was higher than the control group (6.98 +/- 1.13) (P < 0.05; t-test). This study had a statistical power of 0.80 and an alpha value of 0.05. This finding suggests that an increased number of SCE in peripheral lymphocytes is associated with cervical cancer. We consider that the lack of reported association of SCE and cervical cancer might be attributed to the none determination of the statistical power and sample size.

Spontaneous genomic fragility and cell cycle progression in lymphocytes of patients with cervical carcinoma

Thirty patients with invasive carcinoma of the cervix, along with 15 age-matched healthy females as controls, were studied to examine the frequency of spontaneous SCEs, chromosomal aberrations (CAs), and cell cycle progression in lymphocytes. The frequency of SCEs and TCAs was statistically significant in the patients over the control group. The correlation of SCEs and TCAs with the stage of cancer, age, and number of pregnancies was also made. The cell cycle of lymphocytes showed its prolongation in the patients, as is evident from the higher proportion of cells at M1 (metaphase of first cell division after 72 hours).

Choromosome instabililty and sister chromatid exchange (SCE) studies in patients with carcinoma of cervix uteri

Cytogenetic studies have been carried out using the G-banding technique in peripheral blood lymphocytes of 14 patients with carcinoma of the cervix uteri. Simultaneously, sister chromatid exchange (SCE) was also analyzed in the peripheral blood lymphocytes of these patients, along with those of 20 age-matched control subjects. The frequency of aberrant metaphases is significantly higher in patients with carcinoma of the cervix uteri (7.85%) than in the age-matched controls (3.35%). A large number of chromosome aberrations in lymphocytes of these patients have also been detected. Sister chromatid exchange (SCE) was also analyzed in lymphocytes of 14 patients with carcinoma of the cervix uteri and 20 age-matched control subjects. The mean SCE frequencies were 9.44 +/- 0.34 (n = 637) and 6.09 +/- 0.24 (n = 900) per metaphase in patients and controls, respectively. The increase of SCE frequency in cancer patients was statistically significant (p < 0.001), but not seen in controls. Our results suggest that patients with carcinoma of the cervix uteri show a degree of chromosomal instability that might be related to a predisposition to neoplasia.

Nuclear lesions during rat hepatocarcinogenesis. I. Measuring the sister-chromatid exchanges during initiation, promotion and progression of rat hepatocarcinogenesis induced with diethylnitrosamine

Cytogenetic endpoints such as sister-chromatid exchanges (SCEs), chromosomal aberrations and micronuclei (MNs) have been widely used as indicators of genetic damage. However, no systematic attempts have been made to correlate the levels of these cytogenetic endpoints with the different steps of carcinogenesis. In the present report, the induction, accumulation and persistence of SCEs and high frequency cells (HFCs) were measured in liver cells during the initiation, promotion and progression steps of rat hepatocarcinogenesis induced by diethylnitrosamine (DEN). The results indicate that lesions leading to SCEs accumulate during initiation only. When DEN administration is longer than the duration of this first step, SCE values stabilize. After stopping the carcinogenic treatment, the SCE levels decrease to control values whether or not promotion and progression occur.

Sister chromatid exchange analysis in acute leukemia patients

This study was made to show the effects of acute leukemia (AL) and cytostatic drug therapy on chromosomes by sister chromatid exchange (SCE) analysis. Metaphase preparations from peripheral blood lymphocytes (PBL) of 15 patients [13 with acute nonlymphocytic leukemia (ANLL) and one with acute lymphocytic leukemia (ALL), and one with Hodgkin's disease (HD)] were harvested before and after treatment. Mean SCE frequency in the cells was 12.07 +/- 0.15 before therapy and was 14.04 +/- 0.32 after therapy as compared with 7.87 +/- 0.60 in controls. SCE values of patients with AL were significantly higher than those of controls, and this was more conspicuous in the cells that had undergone anticancer treatment.

Study of numerical aberrations of chromosome 1 by fluorescent in situ hybridization and DNA content by densitometric analysis on (pre)-malignant cervical lesions

In an attempt to determine whether the fluorescent in situ hybridization (FISH) can be used as a rapid approach for the identification of aneuploidy in premalignant cervical smears, a centromeric probe for chromosome 1 was used. The results from the FISH experiments were compared with measurements of the overall DNA content obtained by means of an image analysis system. With progression to neoplasia, a decrease of the frequency of cells with two spots was observed, due to an increasing polysomy of chromosome 1. As far as the DNA content was concerned, an increasing DNA index and 5C-exceeding ratio (fraction of cells with a DNA content higher than 5C) was observed. Classification of the FISH results by a linear discriminant analysis revealed that 67.6% of the cases were classified in agreement with the CIN classification. These data suggest that chromosome 1 may be considered as a marker chromosome for pre-malignant cervical lesions and that the DNA content measurements are complementary to the FISH results.

Detection of premalignant stages in cervical smears with a biotinylated probe for chromosome 1

Fluorescence in situ hybridization with (peri-)centromeric probes is an easy method to detect numerical aberrations in nonmitotic and mitotic cells. In this study, cervical smears of premalignant and malignant stages (26 controls, 15 CIN I, 12 CIN II, and 15 CIN III cervical smears) were analyzed for the presence of numerical aberrations of chromosome 1 with a centromeric DNA probe (1q12). With more severe stages a decrease of disomy was observed, merely due to a gain of extra copies of chromosome 1; in some cases, however, monosomy was detected. The frequencies of disomy for chromosome 1 ranged from 65.3% to 95.0% in the controls, from 71.3% to 94.3% in CIN I, from 59.2% to 91.5% in CIN II, and from 23% to 96.2% in CIN III. Polysomy ranged from 0% to 5.7% in the controls, from 0% to 14.4% in CIN I, from 0.9% to 30.8% in CIN II, and from 0.8% to 69.6% in CIN III. Monosomy ranged from 2.6% to 34.1% in the controls, from 0% to 17.5% in CIN I, from 3.6% to 27.5% in CIN II, and from 0.9% to 31.4% in CIN III. The results show that screening for aneuploidy of chromosome 1 allows a good discrimination between control samples and dysplasia. These data suggest that chromosome 1 may be a marker chromosome. They are in accordance with previous cytodensitometric analyses, where already in the preneoplastic stages an increased DNA content (polyploidization with subsequent aneuploidization) is observed.

Sister chromatid exchange in Waldenström's macroglobulinemia

Results on sister chromatid exchange (SCE) frequency and interchromosomal distribution in bone marrow and peripheral blood cultures from patients with Waldenström's macroglobulinemia are reported. PHA-stimulated bone marrow cultures showed increased SCE frequencies in all 12 patients examined. The increase was particularly high in two cases (17.07 and 16.77 SCE/cell, respectively) and, in one of them, a very high SCE level was found in PHA-stimulated peripheral blood culture (40.81 SCE/cell). In LPS-stimulated cultures, increased SCE levels were observed in some patients. Comparison between SCE frequency in bone marrow cell cultures with either mitogen showed a significant increase in PHA-stimulated cultures. Analysis of the interchromosomal SCE distribution revealed significant differences with respect to the control values; however, these differences were variable in the different patients. In pooled data of PHA-stimulated bone marrow cultures, there were differences between expected and observed SCEs in chromosomes 1 and 2 and in B, E, F, and G chromosome groups. Results of cell cycle modifications are also reported.

Sister chromatid exchanges in patients with carcinoma in situ of cervix uteri

Sister chromatid exchange (SCE) was analyzed in lymphocytes of 21 patients with carcinoma in situ of cervix uteri and 19 control subjects. The mean SCE frequencies were 8.92 +/- 0.31 (n = 417) and 6.94 +/- 0.23, (n = 375) per metaphase in patients and controls, respectively. The increase of SCE levels in cancer patients was highly significant in respect to controls (p less than 0.001). Together with data of other authors in patients with precancerous and cancerous lesions of the cervix, our results suggest that there is no correlation between SCE rate and severity of cancerous lesions.

Cyclophosphamide increases the frequency of sister chromatid exchange in direct preparations of human chorionic villi in the absence of supplementary enzymatic activation systems

A study was performed to evaluate the effect on the frequency of sister chromatid exchange in first trimester chorionic villi of two chemical compounds, mitomycin C and cyclophosphamide. Mitomycin C is generally known to induce an increase in sister chromatid exchange both in vivo and in vitro standard conditions. Cyclophosphamide is a compound requiring additional enzymatic enrichment of the culture medium to express its mutagenic activity under in vitro conditions. We exposed chorionic villi samples to these chemicals without the use of conventional cell cultures and without adding enzymatic extracts to the medium. The results indicate a statistically significant increase in the frequency of sister chromatid exchange after exposure to both compounds and also at lower dosages.

Sister chromatid exchange analysis in familial groups of malignant melanoma patients

Sister chromatid exchange (SCE) analysis was carried out on peripheral blood lymphocytes of 20 familial malignant melanoma (FMM) and 39 sporadic malignant melanoma (SMM) untreated patients, belonging to 10 and 39 families, respectively. The study was extended to 39 unaffected close relatives of FMM patients, to 187 unaffected close relatives of SMM patients, and to 20 unaffected unrelated individuals (control group), all examined under the same conditions. The mean SCE rates/cell were significantly higher in MM families than in the control group, and in melanoma patients than in their close relatives. The mean SCE levels of FMM and SMM patients, (8.4 +/- 0.8 and 8.0 +/- 0.3, respectively) were similar, and so were the distributions of individuals in classes of increasing SCE values (with a modal value at 7-8 SCEs/cell). The mean SCE levels of close relatives of FMM and SMM patients were also similar (5.4 +/- 0.2 and 5.4 +/- 0.1, respectively, with a modal value at 4-5 SCEs/cell), and slightly higher than in the control group (4.7 +/- 0.2 SCEs/cell). More than 7 SCEs/cell were observed in the majority (41 of 59) of FMM or SMM patients, in a smaller fraction (25 of 227) unaffected relatives, and in none of 20 unrelated unaffected individuals. These observations favor the hypothesis that higher SCE levels may be an expression of constitutional lesions predisposing to this neoplastic disease.