The impact of an interventional counselling procedure in families with a BRCA1/2 gene mutation : efficacy and safety

Background: Predictive genetic testing has high impact on cancer prevention for BRCA carriers and passing this information in BRCA families is important. Mostly, this is proband-mediated but this path is defective and denies relatives lifesaving information. Objective: To assess the efficacy/safety of an intervention, in which relatives are actively informed. Design: Sequential prospective study in new BRCA families. The proband informed relatives about predictive testing (phase I). After 6 months, a letter was sent to adult relatives who had not been reached (phase II). Then a phone call was made to obtain a final notion of their wishes. All subjects received psychometric testing (State-Trait Anxiety Inventory, STAI), an interview and routine counselling. Results: Twenty families were included. Twenty-four of the relatives could not be reached, 59 were 'decliners', 47 participated by the proband and 42 by the letter. Predictive testing was performed in 98 % of the participants of which 30 were mutation carriers. The intervention is psychologically safe: the 95 % CI for the estimated mean difference in STAI DY1 between phase II/I subjects (mean difference -1.07, 95 % CI -4.4 to 2.35, p = 0.53) shows that the mean STAI DY1 score (measured at first consult) for phase II is no more than 2.35 units higher than for phase I, which is not relevant. Conclusions: A protocol directly informing relatives nearly doubles the number of relatives tested and is psychologically safe. This should lead to a change in counselling guidelines in families with a strong germline predisposition for cancer

Influence of RT-qPCR primer position on EGFR interference efficacy in lung cancer cells

<p>Abstract</p> <p>Background</p> <p>Real-time quantitative RT-PCR (RT-qPCR) is a "gold" standard for measuring steady state mRNA levels in RNA interference assays. The knockdown of the epidermal growth factor receptor (EGFR) gene with eight individual EGFR small interfering RNAs (siRNAs) was estimated by RT-qPCR using three different RT-qPCR primer sets.</p> <p>Results</p> <p>Our results indicate that accurate measurement of siRNA efficacy by RT-qPCR requires careful attention for the selection of the primers used to amplify the target EGFR mRNA.</p> <p>Conclusions</p> <p>We conclude that when assessing siRNA efficacy with RT-qPCR, more than one primer set targeting different regions of the mRNA should be evaluated and at least one of these primer sets should amplify a region encompassing the siRNA recognition sequence.</p

Quantification of epidermal growth factor receptor T790M mutant transcripts in lung cancer cells by real-time reverse transcriptase-quantitative polymerase chain reaction.

peer reviewedA simple and sensitive real-time reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) was developed to quantify threonine-to-methionine substitution at amino acid position 790 (T790M) mutant transcripts in a wild-type (wt) epidermal growth factor receptor background. The assay is based on three unmodified oligonucleotides, and both SYBR Green and a Taqman probe can be used. To increase the discrimination between mutant and wt signals, ARMS (amplification refractory mutation system) and LNA (locked nucleic acid) primers were tested, but a benefit was observed only with plasmids and not with cellular complementary DNA. The RT-qPCR assay using transcript-specific primers can detect as few as 1% T790M transcripts in a wt background and, therefore, will be useful in RNA interference studies specifically targeting mutant RNA

Targeting Polo-like kinase 1 and TRAIL enhances apoptosis in non-small cell lung cancer

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in cancer cells without causing damage to normal cells. However, some tumors are resistant to TRAIL monotherapy and clinical studies assessing targeted agents towards the TRAIL receptor have failed to show robust therapeutic activity. Evidence has shown that standard anti-mitotic drugs can induce synergistic apoptosis upon combination with TRAIL via cell cycle arrest. Polo like kinase-1 (PLK1) plays a critical role in different stages of cell cycle progression and mitosis. A number of investigations have demonstrated that PLK1 inhibition causes cell cycle arrest and mitotic catastrophe in non-small cell lung cancer (NSCLC), and we thus postulated that PLK1 inhibition could enhance TRAIL-induced apoptosis. We demonstrate that the combination of a TRAIL receptor agonist and a PLK1 inhibitor synergistically reduces cell viability, and strongly increases apoptosis in NSCLC cellular models. Consistent with our in vitro observations, this drug combination also significantly reduces tumor growth in vivo. Our data additionally reveal that G2/M cell cycle arrest and downregulation of Mcl-1 and signal transducer and activator of transcription 3 (STAT3) activity following PLK1 inhibition may contribute to the sensitization of TRAIL-induced apoptosis in NSCLC. Together, these data support the further exploration of combined TRAIL and PLK1 inhibition in the treatment of NSCLC

Genomic activation of the EGFR and HER2-neu genes in a significant proportion of invasive epithelial ovarian cancers

<p>Abstract</p> <p>Background</p> <p>The status of the EGFR and HER2-neu genes has not been fully defined in ovarian cancer. An integrated analysis of both genes could help define the proportion of patients that would potentially benefit from targeted therapies.</p> <p>Methods</p> <p>We determined the tumour mutation status of the entire tyrosine kinase (TK) domain of the EGFR and HER2-neu genes in a cohort of 52 patients with invasive epithelial ovarian cancer as well as the gene copy number and protein expression of both genes in 31 of these patients by DGGE and direct sequecing, immunohistochemistry and Fluorescent in Situ Hybridisation (FISH).</p> <p>Results</p> <p>The EGFR was expressed in 59% of the cases, with a 2+/3+ staining intensity in 38%. HER2-neu expression was found in 35%, with a 2/3+ staining in 18%. No mutations were found in exons 18–24 of the TK domains of EGFR and HER2-neu. High polysomy of the EGFR gene was observed in 13% of the invasive epthelial cancers and amplification of the HER2-neu gene was found in 10% and correlated with a high expression level by immunohistochemistry.</p> <p>Mutations within the tyrosine kinase domain were not found in the entire TK domain of both genes, but have been found in very rare cases by others.</p> <p>Conclusion</p> <p>Genomic alteration of the HER2-neu and EGFR genes is frequent (25%) in ovarian cancer. EGFR/HER2-neu targeted therapies should be investigated prospectively and specifically in that subset of patients.</p

Five recurrent BRCA1/2 mutations are responsible for cancer predisposition in the majority of Slovenian breast cancer families

<p>Abstract</p> <p>Background</p> <p>Both recurrent and population specific mutations have been found in different areas of the world and more specifically in ethnically defined or isolated populations. The population of Slovenia has over several centuries undergone limited mixing with surrounding populations.</p> <p>The current study was aimed at establishing the mutation spectrum of <it>BRCA1/2 </it>in the Slovenian breast/ovarian cancer families taking advantage of a complete cancer registration database. A second objective was to determine the cancer phenotype of these families.</p> <p>Methods</p> <p>The original population database was composed of cancer patients from the Institute of Oncology Ljubljana in Slovenia which also includes current follow-up status on these patients. The inclusion criteria for the <it>BRCA1/2 </it>screening were: (i) probands with at least two first degree relatives with breast and ovarian cancer; (ii) probands with only two first degree relatives of breast cancer where one must be diagnosed less than 50 years of age; and (iii) individual patients with breast and ovarian cancer, bilateral breast cancer, breast cancer diagnosed before the age of 40 and male breast cancer without any other cancer in the family.</p> <p>Results</p> <p>Probands from 150 different families met the inclusion criteria for mutation analysis of which 145 consented to testing. A <it>BRCA1/2 </it>mutation was found in 56 (39%). Two novel large deletions covering consecutive exons of <it>BRCA1 </it>were found. Five highly recurrent specific mutations were identified (1806C>T, 300T>G, 300T>A, 5382insC in the <it>BRCA1 </it>gene and IVS16-2A>G in the <it>BRCA2 </it>gene). The IVS16-2A>G in the <it>BRCA2 </it>gene appears to be a unique founder mutation in the Slovenian population. A practical implication is that only 4 PCR fragments can be used in a first screen and reveal the cancer predisposing mutation in 67% of the <it>BRCA1/2 </it>positive families. We also observed an exceptionally high frequency of 4 different pathogenic missense mutations, all affecting one of the cryptic cysteine residues of the <it>BRCA1 </it>Ring Finger domain.</p> <p>Conclusion</p> <p>A high mutation detection rate and the frequent occurrence of a limited array of recurring mutations facilitate <it>BRCA1/2 </it>mutation screening in Slovenian families.</p

The occurrence of germline BRCA1 and BRCA2 sequence alterations in Slovenian population

<p>Abstract</p> <p>Background</p> <p>The <it>BRCA1 </it>and <it>BRCA2 </it>mutation spectrum and mutation detection rates according to different family histories were investigated in 521 subjects from 322 unrelated Slovenian cancer families with breast and/or ovarian cancer.</p> <p>Methods</p> <p>The <it>BRCA1 </it>and <it>BRCA2 </it>genes were screened using DGGE, PTT, HRM, MLPA and direct sequencing.</p> <p>Results</p> <p>Eighteen different mutations were found in <it>BRCA1 </it>and 13 in <it>BRCA2 </it>gene. Mutations in one or other gene were found in 96 unrelated families. The mutation detection rates were the highest in the families with at least one breast and at least one ovarian cancer - 42% for <it>BRCA1 </it>and 8% for <it>BRCA2</it>. The mutation detection rate observed in the families with at least two breast cancers with disease onset before the age of 50 years and no ovarian cancer was 23% for <it>BRCA1 </it>and 13% for <it>BRCA2</it>. The mutation detection rate in the families with at least two breast cancers and only one with the disease onset before the age of 50 years was 11% for <it>BRCA1 </it>and 8% for <it>BRCA2</it>. In the families with at least two breast cancers, all of them with disease onset over the age of 50 years, the detection rate was 5% for <it>BRCA2 </it>and 0% for <it>BRCA1</it>.</p> <p>Conclusion</p> <p>Among the mutations detected in Slovenian population, 5 mutations in <it>BRCA1 </it>and 4 mutations in <it>BRCA2 </it>have not been described in other populations until now. The most frequent mutations in our population were c.181T > G, c.1687C > T, c.5266dupC and c.844_850dupTCATTAC in <it>BRCA1 </it>gene and c.7806-2A > G, c.5291C > G and c.3978insTGCT in <it>BRCA2 </it>gene (detected in 69% of <it>BRCA1 </it>and <it>BRCA2 </it>positive families).</p