Genome-wide screening of DNA copy number alterations in cervical carcinoma patients with CGH+SNP microarrays and HPV-FISH.

Alterations in the genome that lead to changes in DNA sequence copy number are characteristic features of solid tumors. We used CGH+SNP microarray and HPV-FISH techniques for detailed screening of copy number alterations (CNAs) in a cohort of 26 patients with cervical carcinoma (CC). This approach identified CNAs in 96.2% (25/26) of tumors. Array-CGH discovered CNAs in 73.1% (19/26) of samples, HPV-FISH experiments revealed CNAs in additional 23.1% (6/26) of samples. Common gains of genetic sequences were observed in 3q (50.0%), 1q (42.4%), 19q (23.1%), while losses were frequently found in 11q (30.8%), 4q (23.1%) and 13q (19.2%). Chromosomal regions involved in loss of heterozygosity were observed in 15.4% of samples in 8q21, 11q23, 14q21 and 18q12.2. Incidence of gain 3q was associated with HPV 16 and HPV 18 positive samples and simultaneous presence of gain 1q (P = 0.033). We did not found a correlation between incidence of CNAs identified by array-CGH and HPV strain infection and incidence of lymph node metastases. Subsequently, HPV-FISH was used for validation of array-CGH results in 23 patients for incidence of hTERC (3q26) and MYC (8q24) amplification. Using HPV-FISH, we found chromosomal lesions of hTERC in 87.0% and MYC in 65.2% of specimens. Our findings confirmed the important role of HPV infection and specific genomic alterations in the development of invasive cervical cancer. This study also indicates that CGH+SNP microarrays allow detecting genome-wide CNAs and copy-neutral loss of heterozygosity more precisely, however, it may be less sensitive than FISH in samples with low level clonal CNAs.

[The role of smoking in the epigenetic modification of phenotype: the latest knowledge about smoking-induced pathways]. / Uloha koureni v epigeneticke modifikaci fenotypu: nejnovejsi poznatky o patologickych procesech vyvolanych kourenim.

Many environmental factors, including chemicals in cigarette smoke, have deleterious effects on human health. Epidemiological studies have repeatedly confirmed that prenatal exposure to maternal smoking is associated not only with complications of pregnancy, foetal growth retardation and disturbed development, but also with an increased risk of serious diseases manifested during childhood and adulthood. The possible pathways of aberrant foetal programming are the interactions of genes and environmental factors through epigenetic mechanisms. Although these scientific problems are just beginning to be understood, some models of altered epigenetic regulations were described: DNA methylation, non-coding RNA(ncRNA)-mediated gene regulation and histone modification. Our contemporaneous knowledge has confirmed that both active smoking and in utero exposure to cigarette smoke can induce changes in all studied epigenetic pathways, and even can be transmitted to future generations through the male germ line.

Balanced chromosomal translocations in men: relationships among semen parameters, chromatin integrity, sperm meiotic segregation and aneuploidy.

PURPOSE: To analyse relationships between semen parameters, sperm chromatin integrity and frequencies of chromosomally unbalanced, disomic and diploid sperm in 13 Robertsonian and 37 reciprocal translocation carriers and to compare the results with data from 10 control donors. METHODS: Conventional semen analysis, Sperm Chromatin Structure Assay and FISH with probes for chromosomes involved in the individual translocations and for chromosomes X, Y, 7, 8, 13, 18 and 21. RESULTS: Normal semen parameters were found in 30.8 % of Robertsonian and 59.5 % of reciprocal translocation carriers. The rates of unbalanced sperm were 12.0 % in Robertsonian and 55.1 % in reciprocal translocation carriers with no difference between normospermic patients and those showing altered semen parameters. Significantly increased frequencies of spermatozoa showing defects in chromatin integrity and condensation, aneuploidy for chromosomes not involved in a translocation and diploidy were detected in translocation carriers with abnormal semen parameters. Normospermic reciprocal translocation carriers showed an increase in chromosome 13 disomy compared to the control group. There was no relationship between gametic and somatic aneuploidy in 12 translocation carriers studied by FISH on sperm and lymphocytes. The frequency of motile sperm was negatively correlated with the frequency of sperm showing disomy, diploidy and defective chromatin condensation. CONCLUSIONS: Abnormal semen parameters can serve as indicators of an additional risk of forming spermatozoa with defective chromatin and aneuploidy in translocation carriers.

Sperm meiotic segregation, aneuploidy and high risk of delivering an affected offspring in carriers of non-Robertsonian translocation t(13;15).

PURPOSE: To determine the percentage of unbalanced spermatozoa and an interchromosomal effect in two carriers of balanced translocations t(13;15)(q32;q26) and t(13;15)(q32;p11.2). METHODS: Sperm nuclei analysis by fluorescent in situ hybridization for detection of percentage of unbalanced spermatozoa and sperm with disomy of chromosomes X, Y, 8, 18, 21 and diploidy. RESULTS: The incidence of unbalanced spermatozoa was 50.5 % and 44.6 % in patient 1 (P1) and patient 2 (P2), respectively. Partial disomy of chromosome 13 was detected in 13.4 % and 21.3 % of sperm in P1 and P2, respectively. The unbalanced karyotype der(15)t(13;15) was found previously in a son of P1 and in two adult relatives, and prenatally in the family of P2. This demonstrates a high risk of delivering an affected offspring. Significantly increased frequencies of chromosomes 8, 18, X and XY disomy and diploidy were observed in P2, which might either indicate an interchromosomal effect or be related to his asthenoteratozoospermia. CONCLUSIONS: Since the proportions of unbalanced spermatozoa and the risk of delivering an affected offspring are high, prenatal or preimplantation genetic diagnosis is recommended for such patients.

Sperm and embryo analysis of similar t(7;10) translocations transmitted in two families.

OBJECTIVE: To compare the sperm meiotic segregation profiles in two men from families with similar t(7;10) translocations and determine the frequency of unbalanced sperm and preimplantation embryos in one couple. DESIGN: Analysis of sperm nuclei and blastomeres by fluorescence in situ hybridization (FISH). SETTING: Research institute. PATIENT(S): Carriers of balanced translocations t(7;10)(q34;q24) and t(7;10)(q36;q24.3). INTERVENTION(S): Multicolor FISH using probes for chromosomes 7, 10, 8, 18, 21, X, and Y on sperm and preimplantation genetic diagnosis (PGD) of blastomeres. MAIN OUTCOME MEASURE(S): Frequencies of meiotic segregation products in sperm and blastomeres and sperm aneuploidy of chromosomes 8, 18, 21, X, and Y. RESULT(S): Similar meiotic segregation patterns, with preferential alternate segregation (50.6% in patient P1, 48.1% in P2) followed by adjacent 1, adjacent 2 and 3:1 segregations, were observed in the sperm of the two carriers. An interchromosomal effect on the sex chromosomes was found when compared with disomy frequencies reported in control donors. The results of preimplantation genetic diagnosis in the first couple are roughly consistent with the sperm analysis results. CONCLUSION(S): Carriers of similar translocations show similar segregation profiles. The in vitro fertilization method accompanied by preimplantation genetic diagnosis increases the chance of translocation carriers fathering a healthy child.