When used together SS18-SSX fusion-specific and SSX C-terminus immunohistochemistry are highly specific and sensitive for the diagnosis of synovial sarcoma and can replace FISH or molecular testing in most cases.

AIMS: Synovial sarcoma is defined by recurrent t(X;18)(p11;q11) translocations creating SS18-SSX1, SS18-SSX2 or SS18-SSX4 fusions. Recently, a novel rabbit monoclonal antibody designed to identify these fusions (SS18-SSX, clone E9X9V) was proposed to be highly specific (100%), but not completely sensitive (95%) for this diagnosis. Another antibody designed to identify the C-terminal end of SSX (SSX_CT, clone E5A2C) was proposed to be highly sensitive (100%), but not completely specific (96%). We sought to validate these antibodies in an independent cohort. METHODS AND RESULTS: We performed immunohistochemistry for SS18-SSX and SSX_CT on 39 synovial sarcoma samples from 25 patients with confirmed gene rearrangements. Thirty-four (87%) and 36 (92%) were positive for SS18-SSX and SSX_CT, respectively. False-negative staining was associated with suboptimally handled small biopsies and decalcified specimens, even when staining was diffuse and strong in subsequent optimally processed excisions and non-decalcified areas. None of 580 non-synovial sarcoma tumours (76 whole sections, 504 TMA samples) were positive for SS18-SSX (100% specificity), whereas 39 (93% specificity) were positive for SSX_CT. CONCLUSIONS: SS18-SSX fusion-specific IHC is 87-95% sensitive for the diagnosis of synovial sarcoma and highly (perhaps perfectly) specific. Therefore, positive SS18-SSX staining definitively confirms the diagnosis of synovial sarcoma. SSX_CT is less specific (93-96%) but highly sensitive (92%, but approaching 100% when suboptimally processed biopsies and decalcified specimens are excluded). Negative SSX_CT staining may therefore have an ancillary role as a rule-out test for synovial sarcoma. We caution that both antibodies are prone to false-negative staining in decalcified specimens.

MTOR signaling orchestrates stress-induced mutagenesis, facilitating adaptive evolution in cancer.

In microorganisms, evolutionarily conserved mechanisms facilitate adaptation to harsh conditions through stress-induced mutagenesis (SIM). Analogous processes may underpin progression and therapeutic failure in human cancer. We describe SIM in multiple in vitro and in vivo models of human cancers under nongenotoxic drug selection, paradoxically enhancing adaptation at a competing intrinsic fitness cost. A genome-wide approach identified the mechanistic target of rapamycin (MTOR) as a stress-sensing rheostat mediating SIM across multiple cancer types and conditions. These observations are consistent with a two-phase model for drug resistance, in which an initially rapid expansion of genetic diversity is counterbalanced by an intrinsic fitness penalty, subsequently normalizing to complete adaptation under the new conditions. This model suggests synthetic lethal strategies to minimize resistance to anticancer therapy.

Expression of MAGE-A and NY-ESO-1 cancer/testis antigens is enriched in triple-negative invasive breast cancers.

AIMS: A better understanding of the expression of cancer/testis antigens (CTAs) in breast cancer might enable the identification of new immunotherapy options, especially for triple-negative (TN) tumours, which lack expression of the conventional therapeutic targets oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. The aim of this study was to quantify the expression of MAGE-A and NY-ESO-1 CTAs in breast cancer, and relate this to known clinicopathological parameters. METHODS AND RESULTS: We surveyed MAGE-A and NY-ESO-1 expression in an unselected cohort of 367 breast tumours (of which 65 were TN), with accompanying clinical follow-up data, by using immunohistochemical analysis of tissue microarrays. Relevant to their potential as vaccine targets in breast cancer, MAGE-A was expressed in 13% of cases, and NY-ESO-1 in 3.8%, with the majority of tumours showing fairly homogeneous staining within individual tissue cores (~85% of cases with staining in >75% of tumour cells). Most NY-ESO-1-positive cases also expressed MAGE-A (P = 2.06 × 10-9 ), and both were strongly associated with the TN phenotype (P < 0.0001), with the most proliferative and poorly differentiated cases, in paticular, showing genomic instability. This was characterised by coexpression of c-Kit and TTK, and overexpression of p53. CONCLUSIONS: MAGE-A and NY-ESO-1 are frequently expressed in TN breast cancer (~47% and 17% of TN cases, respectively), suggesting that targeting them could be feasible in this patient group. Expression is reasonably homogeneous in positive cases, suggesting that immunohistochemical analysis of tissue biopsies would be a reliable companion biomarker.

The angiotensin receptor blocker, Losartan, inhibits mammary tumor development and progression to invasive carcinoma.

Drugs that target the Renin-Angiotensin System (RAS) have recently come into focus for their potential utility as cancer treatments. The use of Angiotensin Receptor Blockers (ARBs) and Angiotensin-Converting Enzyme (ACE) Inhibitors (ACEIs) to manage hypertension in cancer patients is correlated with improved survival outcomes for renal, prostate, breast and small cell lung cancer. Previous studies demonstrate that the Angiotensin Receptor Type I (AT1R) is linked to breast cancer pathogenesis, with unbiased analysis of gene-expression studies identifying significant up-regulation of AGTR1, the gene encoding AT1R in ER+ve/HER2-ve tumors correlating with poor prognosis. However, there is no evidence, so far, of the functional contribution of AT1R to breast tumorigenesis. We explored the potential therapeutic benefit of ARB in a carcinogen-induced mouse model of breast cancer and clarified the mechanisms associated with its success.Mammary tumors were induced with 7,12-dimethylbenz[α]antracene (DMBA) and medroxyprogesterone acetate (MPA) in female wild type mice and the effects of the ARB, Losartan treatment assessed in a preventative setting (n = 15 per group). Tumor histopathology was characterised by immunohistochemistry, real-time qPCR to detect gene expression signatures, and tumor cytokine levels measured with quantitative bioplex assays. AT1R was detected with radiolabelled ligand binding assays in fresh frozen tumor samples.We showed that therapeutic inhibition of AT1R, with Losartan, resulted in a significant reduction in tumor burden; and no mammary tumor incidence in 20% of animals. We observed a significant reduction in tumor progression from DCIS to invasive cancer with Losartan treatment. This was associated with reduced tumor cell proliferation and a significant reduction in IL-6, pSTAT3 and TNFα levels. Analysis of tumor immune cell infiltrates, however, demonstrated no significant differences in the recruitment of lymphocytes or tumour-associated macrophages in Losartan or vehicle-treated mammary tumors.Analysis of AT1R expression with radiolabelled ligand binding assays in human breast cancer biopsies showed high AT1R levels in 30% of invasive ductal carcinomas analysed. Furthermore, analysis of the TCGA database identified that high AT1R expression to be associated with luminal breast cancer subtype.Our in vivo data and analysis of human invasive ductal carcinoma samples identify the AT1R is a potential therapeutic target in breast cancer, with the availability of a range of well-tolerated inhibitors currently used in clinics. We describe a novel signalling pathway critical in breast tumorigenesis, that may provide new therapeutic avenues to complement current treatments.

An epithelial to mesenchymal transition programme does not usually drive the phenotype of invasive lobular carcinomas.

Epithelial to mesenchymal transition (EMT) is a cellular phenotype switching phenomenon which occurs during normal development and is proposed to promote tumour cell invasive capabilities during tumour progression. Invasive lobular carcinoma (ILC) is a histological special type of breast cancer with a peculiar aetiology - the tumour cells display an invasive growth pattern, with detached, single cells or single files of cells, and a canonical feature is the loss of E-cadherin expression. These characteristics are indicative of an EMT or at the very least that they represent some plasticity between phenotypes. While some gene expression profiling data support this view, the tumour cells remain epithelial and limited immunohistochemistry data suggest that EMT markers may not feature prominently in ILC. We assessed the expression of a panel of EMT markers (fibronectin, vimentin, N-cadherin, smooth muscle actin, osteonectin, Snail, Twist) in 148 ILCs and performed a meta-analysis of publically available molecular data from 154 ILCs. Three out of 148 (2%) ILCs demonstrated an early and coordinated alteration of multiple EMT markers (down-regulation of E-cadherin, nuclear TWIST, and up-regulation of vimentin, osteonectin, and smooth muscle actin). However, the data overall do not support a role for EMT in defining the phenotypic peculiarities of the majority of ILCs. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Asociación entre enfermedad periodontal y disfunción endotelial valorada por vasodilatación mediada por flujo en la arteria braquial: Estudio piloto / Association between periodontal disease and endothelial dysfunction assessed by flow-mediated dilation in the brachial artery: Pilot study

Objetivo: evaluar la disfunción endotelial a través de la vasodilatación mediada por flujo (VMF) en la arteria braquial en pacientes fumadores con periodontitis crónica avanzada y compararla con pacientes fumadores sin enfermedad periodontal, para determinar si hay diferencias en cuando a disfunción endotelial entre quienes presentan o no periodontitis crónica avanzada. Métodos: se incluyeron 30 pacientes con hábito de tabaquismo, 15 con periodontitis crónica avanzada y 15 sin periodontitis. Se realizó historia clínica completa, exámenes de laboratorio y prueba de vasodilatación mediada por flujo de la arteria braquial. Resultados: el estudio mostró que había diferencias significativas en los diámetros finales, resultantes de vasodilatación mediada por flujo (p=0,0328), con menores valores finales para quienes tenían enfermedad periodontal. Las diferencias en las respuestas porcentuales y en el número de personas con disfunción determinada dicotómicamente, no alcanzaron significación estadística. Conclusión: se observó que el grupo de pacientes con periodontitis crónica avanzada tuvo diámetros resultantes luego de la prueba que fueron significativamente menores que los del grupo de controles. Aunque al evaluar las diferencias en porcentajes no se alcanzó significación estadística, el estudio mostró una respuesta claramente menor en vasodilatación en el grupo con enfermedad periodontal.

Objective: To evaluate endothelial dysfunction through flow-mediated vasodilation (FMD) in the brachial artery in smokers with advanced chronic periodontitis and compare it with smokers without periodontal disease, to determine whether there are differences in endothelial dysfunction among those with or without advanced chronic periodontitis. Methods: We included 30 patients with smoking habit, 15 with advanced chronic periodontitis and 15 without periodontal disease. We performed a complete medical history, laboratory tests and flow-mediated vasodilation test of the brachial artery. Results: The study showed that there were significant differences in the final diameters, resulting from flow-mediated dilation (p = 0.0328), with lower final values for those with periodontal disease. The differences in the percentage responses and the number of people with specific dysfunction determined dichotomously did not reach statistical significance. Conclusion: We observed that the group of patients with advanced chronic periodontitis had after the test resulting diameters that were significantly lower than those in the control group. Although when evaluating differences in percentages no statistical significance was found, the study showed a clearly lower response in vasodilation in the group with periodontal disease.

SNORD-host RNA Zfas1 is a regulator of mammary development and a potential marker for breast cancer.

Long noncoding RNAs (lncRNAs) are increasingly recognized to play major regulatory roles in development and disease. To identify novel regulators in breast biology, we identified differentially regulated lncRNAs during mouse mammary development. Among the highest and most differentially expressed was a transcript (Zfas1) antisense to the 5' end of the protein-coding gene Znfx1. In vivo, Zfas1 RNA is localized within the ducts and alveoli of the mammary gland. Zfas1 intronically hosts three previously undescribed C/D box snoRNAs (SNORDs): Snord12, Snord12b, and Snord12c. In contrast to the general assumption that noncoding SNORD-host transcripts function only as vehicles to generate snoRNAs, knockdown of Zfas1 in a mammary epithelial cell line resulted in increased cellular proliferation and differentiation, while not substantially altering the levels of the SNORDs. In support of an independent function, we also found that Zfas1 is extremely stable, with a half-life >16 h. Expression analysis of the SNORDs revealed these were expressed at different levels, likely a result of distinct structures conferring differential stability. While there is relatively low primary sequence conservation between Zfas1 and its syntenic human ortholog ZFAS1, their predicted secondary structures have similar features. Like Zfas1, ZFAS1 is highly expressed in the mammary gland and is down-regulated in breast tumors compared to normal tissue. We propose a functional role for Zfas1/ ZFAS1 in the regulation of alveolar development and epithelial cell differentiation in the mammary gland, which, together with its dysregulation in human breast cancer, suggests ZFAS1 as a putative tumor suppressor gene.