BackgroundBreast cancer is rarely diagnosed in very young women (35years old or younger), and it often presents with distinct clinical-pathological features related to a more aggressive phenotype and worse prognosis when diagnosed at this early age. A pending question is whether breast cancer in very young women arises from the deregulation of different underlying mechanisms, something that will make this disease an entity differentiated from breast cancer diagnosed in older patients.MethodsWe performed a comprehensive study of miRNA expression using miRNA Affymetrix2.0 array on paraffin-embedded tumour tissue of 42 breast cancer patients 35 years old or younger, 17 patients between 45 and 65 years old and 29 older than 65 years. Data were statistically analyzed by t-test and a hierarchical clustering via average linkage method was conducted. Results were validated by qRT-PCR. Putative targeted pathways were obtained using DIANA miRPath online software.ResultsThe results show a differential and unique miRNA expression profile of 121 miRNAs (p-value <0.05), 96 of those with a FDR-value <0.05. Hierarchical clustering grouped the samples according to their age, but not by subtype nor by tumour characteristics. We were able to validate by qRT-PCR differences in the expression of 6 miRNAs: miR-1228*, miR-3196, miR-1275, miR-92b, miR-139 and miR-1207. Moreover, all of the miRNAs maintained the expression trend. The validated miRNAs pointed out pathways related to cell motility, invasion and proliferation.ConclusionsThe study suggests that breast cancer in very young women appears as a distinct molecular signature. To our knowledge, this is the first time that a validated microRNA profile, distinctive to breast cancer in very young women, has been presented. The miRNA signature may be relevant to open an important field of research in order to elucidate the underlying mechanism in this particular disease, which in a more clinical setting, could potentially help to identify therapeutic targets in this particular set of patients.

The incidence and mortality of endometrial cancer (EC) have risen in recent years, hence more precise management is needed. Therefore, we combined different types of liquid biopsies to better characterize the genetic landscape of EC in a non-invasive and dynamic manner. Uterine aspirates (UAs) from 60 patients with EC were obtained during surgery and analyzed by next-generation sequencing (NGS). Blood samples, collected at surgery, were used for cell-free DNA (cfDNA) and circulating tumor cell (CTC) analyses. Finally, personalized therapies were tested in patient-derived xenografts (PDXs) generated from the UAs. NGS analyses revealed the presence of genetic alterations in 93% of the tumors. Circulating tumor DNA (ctDNA) was present in 41.2% of cases, mainly in patients with high-risk tumors, thus indicating a clear association with a more aggressive disease. Accordingly, the results obtained during the post-surgery follow-up indicated the presence of ctDNA in three patients with progressive disease. Moreover, 38.9% of patients were positive for CTCs at surgery. Finally, the efficacy of targeted therapies based on the UA-specific mutational landscape was demonstrated in PDX models. Our study indicates the potential clinical applicability of a personalized strategy based on a combination of different liquid biopsies to characterize and monitor tumor evolution, and to identify targeted therapies.

Usher syndrome type I is the most severe form of Usher syndrome. It is an autosomal recessive disorder characterized by profound congenital sensorineural deafness, retinitis pigmentosa, and vestibular abnormalities. Mutations in the myosin VIIA gene (MYO7A) are responsible for Usher syndrome type 1B (USH1B). This gene is thought to bear greatest responsibility for USH1 and, depending on the study, has been reported to account for between 24% and 59% of USH1 cases. In this report a mutation screening of the MYO7A gene was carried out in a series of 48 unrelated USH1 families using single strand conformation polymorphism analysis (SSCP) and direct sequencing of those fragments showed an abnormal electrophoretic pattern. Twenty-five mutations were identified in 23 out of the 48 families studied (47.9%). Twelve of these mutations were novel, including five missense mutations, three premature stop codons, three frameshift, and one putative splice-site mutation. Based on our results we can conclude there is an absence of hot spot mutations in the MYO7A gene and that this gene plays a major role in Usher syndrome.

BackgroundHuman pigmentation is a polygenic quantitative trait with high heritability. In addition to genetic factors, it has been shown that pigmentation can be modulated by oestrogens and androgens via up- or down-regulation of melanin synthesis. Our aim was to identify possible sex differences in pigmentation phenotype as well as in melanoma association in a melanoma case-control population of Spanish origin.MethodsFive hundred and ninety-nine females (316 melanoma cases and 283 controls) and 458 males (234 melanoma cases and 224 controls) were analysed. We genotyped 363 polymorphisms (single nucleotide polymorphisms (SNPs)) from 65 pigmentation gene regions.ResultsWhen samples were stratified by sex, we observed more SNPs associated with dark pigmentation and good sun tolerance in females than in males (107 versus 75; P = 2.32 × 10−6), who were instead associated with light pigmentation and poor sun tolerance. Furthermore, six SNPs in TYR, SILV/CDK2, GPR143, and F2RL1 showed strong differences in melanoma risk by sex (P < 0.01).ConclusionsWe demonstrate that these genetic variants are important for pigmentation as well as for melanoma risk, and also provide suggestive evidence for potential differences in genetic effects by sex.Electronic supplementary materialThe online version of this article (doi:10.1186/s13293-016-0070-1) contains supplementary material, which is available to authorized users.

MiRNAs are part of the epigenetic machinery, and are also epigenetically modified by DNA methylation. MiRNAs regulate expression of different genes, so any alteration in their methylation status may affect their expression. We aimed to identify methylation differences in miRNA encoding genes in breast cancer affecting women under 35 years old (BCVY), in order to identify potential biomarkers in these patients. In Illumina Infinium MethylationEPIC BeadChip samples (metEPICVal), we analysed the methylation of 9,961 CpG site regulators of miRNA-encoding genes present in the array. We identified 193 differentially methylated CpG sites in BCVY (p-value < 0.05 and methylation differences ±0.1) that regulated 83 unique miRNA encoding genes. We validated 10 CpG sites using two independent datasets based on Infinium Human Methylation 450k array. We tested gene expression of miRNAs with differential methylation in BCVY in a meta-analysis using The Cancer Genome Atlas (TCGA), Clariom D and Affymetrix datasets. Five miRNAs (miR-9, miR-124-2, miR-184, miR-551b and miR-196a-1) were differently expressed (FDR p-value < 0.01). Finally, only miR-124-2 shows a significantly different gene expression by quantitative real-time PCR. MiR-124-hypomethylation presents significantly better survival rates for older patients as opposed to the worse prognosis observed in BCVY, identifying it as a potential specific survival biomarker in BCVY.

At the histological level, tumor budding in colon cancer is the result of cells undergoing at least partial epithelial-to-mesenchymal transition. The microRNA 200 family is an important epigenetic driver of this process, mainly by downregulating zinc-finger E-box binding homeobox (ZEB) and transforming growth factor beta (TGF-β) expression. We retrospectively explored the expression of the miR200 family, and ZEB1 and ZEB2, and their relationship with immune resistance mediated through PD-L1 overexpression. For this purpose, we analyzed a series of 125 colon cancer cases and took samples from two different tumor sites: the area of tumor budding at the invasive front and from the tumor center. We found significant ZEB overexpression and a reduction in miR200 in budding areas, a profile compatible with epithelial-to-mesenchymal transition. In multivariate analysis of the cases with localized disease, low miR200c expression in budding areas, but not at the tumor center, was an adverse tumor-specific survival factor (hazard ratio: 0.12; 95% confidence interval: 0.03-0.81; p = 0.02) independent of the clinical stage of the disease. PD-L1 was significantly overexpressed in the budding areas and its levels correlated with a mesenchymal transition profile. These results highlight the importance of including budding areas among the samples used for biomarker evaluation and provides relevant data on the influence of mesenchymal transition in the immune resistance mediated by PD-L1 overexpression.

Neuroblastoma (NB) is a pediatric cancer of highly variable clinical outcome. Much effort is devoted to detection of minimal residual (MRD) disease through RT-PCR or immunology of tissue-specific markers. Tyrosine hyrdroxylase (TH) has demonstrated a high utility to assess disease dissemination, although this marker can be lost due to clonal variability. Here we propose the use of the doublecortin (DCX) gene as a new molecular marker of neuroblastoma cells. DCX specifically appears in migrating neurons of the central and peripheral nervous system and interacts with and regulates the microtobule cytoskeleton. We have studied this gene by real-time quantitative RT-PCR in a total of 47 primary tumors and 202 samples of bone marrow or peripheral blood from 34 high-risk neuroblastoma patients as well as in 41 normal controls. The expression of DCX demonstrated a good specificity and concordance with TH, showing a higher expression rate in all the sample types studied as well as at different time points from diagnosis. We conclude that DCX would be a more efficient marker of minimal disease in neuroblastoma and perhaps other tumors of neuronal lineage.

Purpose: Breast cancer (BC) in very young women (BCVY) is more aggressive than in older women. The purpose of this study was to evaluate the relevance of a range of clinico-pathological factors in the prognosis of BCVY patients. Methods: We retrospectively analyzed 258 patients diagnosed with BCVY at our hospital from 1998 to 2014; the control group comprised 101 older patients with BC. We correlated clinicopathological factors, treatments, relapse and exitus with age and with previously published miRNA expression data. Results: We identified some significant differences in risk factors between BCVY and older patients. The age at menarche, number of pregnancies, and age at first pregnancy were lower in the BCVY group and had a greater probability of recurrence and death in all cases. Lymph node-positive patients in the BCVY group are associated with a worse prognosis ( P = .02), an immunohistochemical HER2 + subtype, and disease relapse ( P = .03). Moreover, there was a shorter time between diagnosis and first relapse in BCVY patients compared with controls, and they were more likely to die from the disease ( P = .002). Finally, from our panel of miRNAs deregulated in BC, reduced miR-30c expression was associated with more aggressive BC in very young patients, lower overall survival, and with axillary lymph node metastases. Conclusions: Patient age and axillary lymph node status post-surgery are independent and significant predictors of distant disease-free survival, local recurrence-free survival, and overall survival. The HER2 + subtype and lower miR-30c expression are related to poor prognosis in lymph node-positive young BC patients.