Despite that Robertsonian translocations (ROBs) are the most common chromosomal rearrangements in humans (1/1000 individuals), an exact breakpoint and the molecular mechanisms leading to their formation are still not well known. This is partly due to the fact that Human Genome Project did not provide any map or sequence for the acrocentric short arms. The main aim of our studies was to narrow the breakpoints in de novo arising and in familial cases of the most frequently occurring ROBs, using eight, previously not tested clones derived from 21p. Our results from PCR and FISH analysis showed that only the clones CR382285, CR382287, and a small fragment of CR382332 are retained in the examined ROBs. Moreover, interphase FISH on monochromosomal hybrids verified the orientation of studied clones in relation to centromeres of chromosomes 14 and 21. Given our results, we propose localization of the breakpoints in or nearby to clone CR382332. Summarizing, our results allowed to narrow the region where the breakpoints are localized and demonstrated that their position could be the same in all common ROBs.Electronic supplementary materialThe online version of this article (doi:10.1007/s10577-014-9439-3) contains supplementary material, which is available to authorized users.

The transmission of brain activity during constant attention test was estimated by means of the short-time directed transfer function (SDTF). SDTF is an estimator based on a multivariate autoregressive model. It determines the propagation as a function of time and frequency. For nine healthy subjects the transmission of EEG activity was determined for target and non-target conditions corresponding to pressing of a switch in case of appearance of two identical images or withholding the reaction in case of different images. The involvement of prefrontal and frontal cortex manifested by the propagation from these structures was observed, especially in the early stages of the task. For the target condition there was a burst of propagation from C3 after pressing the switch, which can be interpreted as beta rebound upon completion of motor action. In case of non-target condition the propagation from F8 or Fz to C3 was observed, which can be connected with the active inhibition of motor cortex by right inferior frontal cortex or presupplementary motor area.

In this study, we analyzed the expression profile of four genes (CCNA2, CCNB1, CCNB2, and CDK1) in laryngeal squamous cell carcinoma (LSCC) cell lines and tumor samples. With the application of microarray platform, we have shown the overexpression of these genes in all analyzed LSCC samples in comparison to non-cancer controls from head and neck region. We have selected CDK1 for further analysis, due to its leading role in cell cycle regulation. It is a member of the Ser/Thr protein kinase family of proven oncogenic properties. The results obtained for CDK1 were further confirmed with the application of reverse transcription quantitative polymerase chain reaction (RT-qPCR) technique, Western blot, and immunohistochemistry (IHC). The observed upregulation of CDK1 in laryngeal squamous cell carcinoma has encouraged us to analyze for genetic mechanisms that can be responsible this phenomenon. Therefore, with the application of array-CGH, sequencing analysis and two methods for epigenetic regulation analysis (DNA methylation and miRNA expression), we tried to identify such potential mechanisms. Our attempts to identify the molecular mechanisms responsible for observed changes failed as we did not observe significant alterations neither in the DNA sequence nor in the gene copy number that could underline CDK1 upregulation. Similarly, the pyrosequencing and miRNA expression analyses did not reveal any differences in methylation level and miRNA expression, respectively; thus, these mechanisms probably do not contribute to elevation of CDK1 expression in LSCC. However, our results suggest that alteration of CDK1 expression on both mRNA and protein level probably appears on the very early step of carcinogenesis.Electronic supplementary materialThe online version of this article (doi:10.1007/s13277-016-4991-4) contains supplementary material, which is available to authorized users.

No abstract