X chromosome inactivation pattern in BRCA gene mutation carriers.

An association of preferential X chromosome inactivation (XCI) with BRCA gene status and breast/ovarian cancer risk has been reported. We evaluated XCI in a large group of BRCA mutation carriers compared to non-carriers and investigated associations between preferential XCI (⩾90:10) and age, mutated gene, cancer development and chemotherapy. XCI was analysed by human androgen receptor (HUMARA) assay and pyrosequencing in 437 BRCA1 or BRCA2 mutation carriers and 445 age-matched controls. The distribution of XCI patterns in the two groups was compared by logistic regression analysis. The association between preferential XCI and selected variables was investigated in both univariate and multivariate fashion. In univariate analyses preferential XCI was not significantly associated with the probability of being a BRCA mutation carrier, nor with cancer status, whereas chemotherapeutic regime and age both showed a significant association. In multivariate analysis only age maintained significance (odds ratio, 1.056; 95% confidence interval, 1.016-1.096). Our findings do not support the usefulness of XCI analysis for the identification of BRCA mutation carriers and cancer risk assessment. The increasing preferential XCI frequency with ageing and the association with chemotherapy justify extending the investigation to other categories of female cancer patients to identify possible X-linked loci implicated in cell survival

Semi-quantitative fragment analysis of the Δexon5q isoform.

<p>The upper panel shows the capillary electrophoresis patterns of the cDNA fragments spanning <i>BRCA1</i> exons 5 and 6 observed in LCLs from a <i>BRCA1</i> wild type individual, and from carriers of the c.190T>C and c.212G>A, which causes the up-regulation of the Δexon5q transcript, mutations. The Δexon5q and full-length (FL) isoforms are indicated. The lower panel shows the ratio between the peak areas of the Δexon5q and full-length isoforms. The LCLs were cultured in the presence (dark grey bars) and in the absence (light grey bar) of cycloheximide. Control bars represent the average value observed in six wild-type LCLs. c.190T>C bars represent the average value observed in four mutant LCLs. The error bars represent standard deviation.</p

Detection of BRCA1/BARD1 interaction by GFP-fragment reassembly screening.

<p>(a) Fluorescence was observed after 24 h of growth at 30°C followed by 2 days of incubation at RT. No fluorescence is observed under non-inducing condition (right column). [L-ara, L-arabinose; IPTG, Isopropyl β-D-1-tiogalattopiranoside, IPTG]. (b) SDS-PAGE of purified, reassembled complexes by IMAC methods. The expected molecular masses are indicated on the left. [<b>*</b>Non-specific band. B^N, H₆-NfrGFPBARD1; Z^N, H₆-ZNfrGFP; Z^C, ZCfrGFP-HA]. (c) Expression of NfrGFP-BARD1 and CfrGFP-BRCA1 wild-type and mutant forms.</p

Number and frequencies of <i>BRCA1</i> c.190T>C positive families among those recruited at three Italian institutions and tested for BRCA mutations.

*<p>Intake criteria for BRCA testing are described in Manoukian et al <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0086924#pone.0086924-Manoukian1" target="_blank">[38]</a>.</p

Clinical and pathological features of <i>BRCA1</i> c.190T>C related ovarian cancer cases.

<p>Clinical and pathological features of <i>BRCA1</i> c.190T>C related ovarian cancer cases.</p

Geographical distribution of <i>BRCA1</i> c.190T>C (p.Cys64Arg) mutation carriers.

<p>Symbol (“•”) indicates the birth places of index case from families segregating the mutation.</p

Clinical and pathological features of <i>BRCA1</i> c.190T>C related breast cancer cases.

a<p>Ductal and lobular type.</p

Haplotype branching trees in families segregating the <i>BRCA1</i> c.190T>C (p.Cys64Arg).

<p>The six short tandem repeat markers analyzed are shown together with their position in the Marshfield genetic map. Family haplotypes are indicated with the corresponding family ID codes. The most common haplotype is indicated in bold numbers.</p