DNA damage and repair biomarkers in cervical cancer patients treated with neoadjuvant chemotherapy: An exploratory analysis

Cervical cancer cells commonly harbour a defective G1/S checkpoint owing to the interaction of viral oncoproteins with p53 and retinoblastoma protein. The activation of the G2/M checkpoint may thus become essential for protecting cancer cells from genotoxic insults, such as chemotherapy. In 52 cervical cancer patients treated with neoadjuvant chemotherapy, we investigated whether the levels of phosphorylated Wee1 (pWee1), a key G2/M checkpoint kinase, and y-H2AX, a marker of DNA double-strand breaks, discriminated between patients with a pathological complete response (pCR) and those with residual disease. We also tested the association between pWee1 and phosphorylated Chk1 (pChk1), a kinase acting upstream Wee1 in the G2/M checkpoint pathway. pWee1, y-H2AX and pChk1 were retrospectively assessed in diagnostic biopsies by immunohistochemistry. The degrees of pWee1 and pChk1 expression were defined using three different classification methods, i.e., staining intensity, Allred score, and a multiplicative score. y-H2AX was analyzed both as continuous and categorical variable. Irrespective of the classification used, elevated levels of pWee1 and y-H2AX were significantly associated with a lower rate of pCR. In univariate and multivariate analyses, pWee1 and y-H2AX were both associated with reduced pCR. Internal validation conducted through a re-sampling without replacement procedure confirmed the robustness of the multivariate model. Finally, we found a significant association between pWee1 and pChk1. The message conveyed by the present analysis is that biomarkers of DNA damage and repair may predict the efficacy of neoadjuvant chemotherapy in cervical cancer. Further studies are warranted to prospectively validate these encouraging findings

Y chromosome analysis reveals a sharp genetic boundary in the Carpathian region

Nine single nucleotide (SNP) or indel binary polymorphisms were used to determine the frequencies and phylogenetic relationships of 12Y chromosomal haplogroups in 289 males from Romania and the Republic of Moldova. Our data indicated a low but not null rate of the homoplasic appearance of the DYZ3 (-) allelic state. All other markers confirmed the previously proposed phylogeny. Based on the affinities between populations in terms of haplogroup frequencies, this work identified the geographical region of the Carpathians as a break point in the gene geography of Eastern Central Europe, providing a finer definition of one of the possible sharp genetic changes between Western and Eastern Europe

Ordering of 44 genetic markers in the 6p22 cytogenetic band

[No abstract available

Autosomal dominant pure cerebellar ataxia. Neurological and genetic study.

A family with late-onset autosomal dominant pure cerebellar ataxia was studied both neurologically and genetically. Neuroimaging and electrophysiological results were in agreement with the clinical evidence showing involvement of the cerebellar system only, even many years after onset. No atrophy of inferior olives was observed by magnetic resonance imaging, while cerebellar atrophy was extremely marked. A very slow disease progression was observed in all patients. The disease can be differentiated from autosomal dominant olivo-ponto-cerebellar atrophies, and in particular from spinocerebellar ataxia type 1 mapping on chromosome 6p, which shows an early multisystemic involvement and a more rapid progression toward inability. A genetic study of the family with the 6p DNA marker D6S89 closely linked to the spinocerebellar ataxia type 1 locus was performed. Results showed significant exclusion of a linkage between the disease and the marker within a distance of 8.5% recombination, indicating that genetic heterogeneity underlies phenotypic differences

Characterization of a small family (CAIII) of microsatellite-containing sequences with X-Y homology

Four X-linked loci showing homology with a previously described Y- linked polymorphic locus (DYS413) were identified and characterized. By fluorescent in situ hybridization (FISH), somatic cell hybrids, and YAC screening, the X-linked members of this small family of sequences (CAIII) all map in Xp22, while the Y members map in Yq 11. These loci contribute to the overall similarity of the two genomic regions. All of the CAIII loci contain an internal microsatellite of the (CA)(n) type. The microsatellites display extensive length polymorphism in two of the X-linked members as well as in the Y members. In addition, common sequence variants are found in the portions flanking the microsatellites in two of the X-linked members. Our results indicate that, during the evolution of this family, length variation on the Y chromosome was accumulated at a rate not slower than that on the X chromosome. Finally, these sequences represent a model system with which to analyze human populations for similar X- and Y-linked polymorphisms

Recurrent simple tandem repeat mutations during human Y-chromosome radiation in Caucasian subpopulations

The haplotypes at four polymorphic loci of the Y chromosome were determined in 245 Caucasian males from 12 subpopulations. The data show that haplotype radiation occurred among Caucasians. Haplotype radiation was accompanied by recurrent mutations at STR loci that caused partial randomization of haplotype structure. The present distribution of alleles at short tandem repeats (STRs) can be explained by a mutation pattern similar to those described for autosomal STRs. The degree of variation among groups of subpopulations was assayed by using the Analysis of Molecular Variance. The results confirm a faster divergence of the Y chromosome as compared to the rest of the genome

The gene for autosomal dominant spinocerebellar ataxia (SCA1) maps telomeric to the HLA complex and is closely linked to the D6S89 locus in three large kindreds

We studied three large kindreds with the HLA-linked form of spinocerebellar ataxia (SCA1) in order to localize the SCA1 locus on the short arm of chromosome 6 (6p). Two loci containing highly informative dinucleotide repeat sequences were used for linkage analysis. These two loci are D6S89, which is telomeric to the HLA region, and T complex-associated testes-expressed 1 (TCTE1), centromeric to HLA. Pairwise linkage analysis of SCA1 and D6S89 revealed a maximum lod score of 5.86 in the Houston SCA1 (HSCA1) kindred and of 8.08 in the Calabrian SCA1 (SCA1) kindreds, at recombination fractions of .050 and .022, respectively. A maximum pairwise lod score of 4.54 at a recombination frequency of .100 was obtained for SCA1 and TCTE1 in the HSCA1 kindred. No evidence for linkage was detected between TCTE1 and SCA1 in the CSCA1 kindreds. Multilocus linkage analysis of SCA1, HLA, and D6S89 in all three kindreds provided strong evidence for localization of the SCA1 locus telomeric to the HLA regions. However, multilocus linkage analysis of SCA1, HLA, and TCTE1 with HSCA1 family genotypes indicated the possibility of a location of the SCA1 locus centromeric to HLA. An analysis of HSCA1 recombinants in this region of chromosome 6 revealed relatively high recombination frequencies between HLA and each of the other two markers and relatively low frequencies between the latter and SCA1, predicting that the SCA1 locus would tend to segregate away from HLA together with D6S89 or TCTE1, as found with the three-point linkage analyses for this family. The results of the pairwise linkage analysis in HSCA1 and CSCA1 and of multilocus linkage analysis in the Calabrian kindreds support a single SCA1 locus telomeric to the HLA region on 6p

The gene for autosomal dominant spinocerebellar ataxia (SCA1) maps centromeric to D6S89 and shows no recombination, in nine large kindreds, with a dinucleotide repeat at the AM10 locus

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant disorder which is genetically linked to the short arm of chromosome 6, telomeric to the human major histocompatibility complex (HLA) and very close to D6S89. Previous multipoint linkage analysis using HLA, D6S89, and SCA1 suggested that SCA1 maps centromeric to D6S89. Data from this study using nine large kindreds indicate a maximum lod score between SCA1 and D6S89 of 67.58 at a maximum recombination fraction of .004. To localize SCA1 more precisely, we identified five dinucleotide polymorphisms near D6S89. Genotypic analyses at these polymorphic loci were carried out in nine multigeneration SCA1 kindreds and in the Centre d'Etude du Polymorphisme Humain reference families. A new marker, AM10GA, demonstrates no recombination with SCA1. The maximum lod score for AM10GA linkage to SCA1 is 42.14 at a recombination fraction of 0. Linkage analysis and analysis of recombination events confirm that SCA1 maps centromeric to D6S89 and establish the following order: CEN-D6S109-AM10GA/SCA1-D6S89-LR40-D6S20 2-TEL