Mutation analysis of BRCA1 and BRCA2 genes in Iranian high risk breast cancer families

Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any association between telomerase sub-units: hTERT and hTR and the prognostic indicators including tumour's size and grade, nodal status and patient's age. Methods: Tumour samples from 46 patients with primary invasive breast cancer and 3 patients with benign tumours were collected. RT-PCR analysis was used for the detection of hTR, hTERT, and PGM1 (as a housekeeping) genes expression. Results: The expression of hTR and hTERT was found in 31(67.4%) and 38 (82.6%) samples respectively. We observed a significant association between hTR gene expression and younger age at diagnosis (p = 0.019) when comparing patients ≤ 40 years with those who are older than 40 years. None of the benign tumours expressed hTR gene. However, the expression of hTERT gene was revealed in 2 samples. No significant association between hTR and hTERT expression and tumour's grade, stage and nodal status was seen. Conclusion: The expression of hTR and hTERT seems to be independent of tumour's stage. hTR expression probably plays a greater role in mammary tumourogenesis in younger women (≤ 40 years) and this may have therapeutic implications in the context of hTR targeting strategies

Purification of Circulating Cell-Free DNA from Plasma and Urine Using the Automated Large-Volume Extraction on the QIAsymphony (R) SP Instrument

Increasing sample numbers for screening and diagnostics using circulating cell-free DNA (ccfDNA) as analyte demands an automated solution for ccfDNA extraction. The efficiency of a new, automated, large volume ccfDNA extraction method was evaluated against a manual reference method. The new kit for automated ccfDNA extraction on the QIAsymphony showed a comparable yield of total ccfDNA from healthy donors as well as a comparable recovery of circulating cancer and fetal DNA. In conclusion, a new kit for automated ccfDNA extraction was established successfully

Suppression of polyploidy by the BRCA2 protein

Mounting evidence implicates BRCA2 not only in maintenance of genome integrity but also in cell-cycle checkpoints. However, the contribution of BRCA2 in the checkpoints is still far from being understood. Here, we demonstrate that breast cancer cells MX-1 are unable to maintain genome integrity, which results in gross polyploidization. We generated MX-1 clones, stably expressing BRCA2, and found that BRCA2 acts to suppress polyploidy. Compared with MX-1, the ectopically BRCA2-expressing cells had different intracellular levels of Aurora A, Aurora B, p21, E2F-1, and pRb, suggesting a BRCA2-mediated suppression of polyploidy via stabilization of the checkpoint proteins levels

Fetal Aneuploidy Detection by Cell-Free DNA Sequencing for Multiple Pregnancies and Quality Issues with Vanishing Twins

Non-invasive prenatal testing (NIPT) by random massively parallel sequencing of maternal plasma DNA for multiple pregnancies is a promising new option for prenatal care since conventional non-invasive screening for fetal trisomies 21, 18 and 13 has limitations and invasive diagnostic methods bear a higher risk for procedure related fetal losses in the case of multiple gestations compared to singletons. In this study, in a retrospective blinded analysis of stored twin samples, all 16 samples have been determined correctly, with four trisomy 21 positive and 12 trisomy negative samples. In the prospective part of the study, 40 blood samples from women with multiple pregnancies have been analyzed (two triplets and 38 twins), with two correctly identified trisomy 21 cases, confirmed by karyotyping. The remaining 38 samples, including the two triplet pregnancies, had trisomy negative results. However, NIPT is also prone to quality issues in case of multiple gestations: the minimum total amount of cell-free fetal DNA must be higher to reach a comparable sensitivity and vanishing twins may cause results that do not represent the genetics of the living sibling, as described in two case reports