Detection of minor, genetically distinct subpopulations within tumors is a key challenge in cancer genomics. Here we report STAR-FISH (specific-to-allele PCR-FISH), a novel method for the combined ...detection of single-nucleotide and copy number alterations in single cells in intact archived tissues. Using this method, we assessed the clinical impact of changes in the frequency and topology of PIK3CA mutation and HER2 (ERBB2) amplification within HER2-positive breast cancer during neoadjuvant therapy. We found that these two genetic events are not always present in the same cells. Chemotherapy selects for PIK3CA-mutant cells, a minor subpopulation in nearly all treatment-naive samples, and modulates genetic diversity within tumors. Treatment-associated changes in the spatial distribution of cellular genetic diversity correlated with poor long-term outcome following adjuvant therapy with trastuzumab. Our findings support the use of in situ single cell-based methods in cancer genomics and imply that chemotherapy before HER2-targeted therapy may promote treatment resistance.
Lobular carcinoma in situ (LCIS) is both a risk indicator and non-obligate precursor of invasive lobular carcinoma (ILC). We sought to characterize the transcriptomic features of LCIS and ILC, with a ...focus on the identification of intrinsic molecular subtypes of LCIS and the changes involved in the progression from normal breast epithelium to LCIS and ILC.
Fresh-frozen classic LCIS, classic ILC, and normal breast epithelium (N) from women undergoing prophylactic or therapeutic mastectomy were prospectively collected, laser-capture microdissected, and subjected to gene expression profiling using Affymetrix HG-U133A 2.0 microarrays.
Unsupervised hierarchical clustering of 40 LCIS samples identified 2 clusters of LCIS distinguished by 6431 probe sets (p < 0.001). Genes identifying the clusters included proliferation genes and other genes related to cancer canonical pathways such as TGF beta signaling, p53 signaling, actin cytoskeleton, apoptosis and Wnt-Signaling pathway. A supervised analysis to identify differentially expressed genes (p < 0.001) between normal epithelium, LCIS, and ILC, using 23 patient-matched triplets of N, LCIS, and ILC, identified 169 candidate precursor genes, which likely play a role in LCIS progression, including PIK3R1, GOLM1, and GPR137B. These potential precursor genes map significantly more frequently to 1q and 16q, regions frequently targeted by gene copy number alterations in LCIS and ILC.
Here we demonstrate that classic LCIS is a heterogeneous disease at the transcriptomic level and identify potential precursor genes in lobular carcinogenesis. Understanding the molecular heterogeneity of LCIS and the potential role of these potential precursor genes may help personalize the therapy of patients with LCIS.
•Lobular carcinoma in situ (LCIS) is a non-obligate precursor to breast cancer.•We demonstrate that LCIS is heterogeneous at the level of the transcriptome.•Copy number alterations in LCIS and ILC result in gene expression changes.•Candidate precursor genes may play a role in the progression of LCIS.
Background
Newly proposed models of breast tumorigenesis suggest that low- and high-grade lesions have distinct tumor progression pathways. Our objective was to examine the relationship between ...histologic grade and molecular subtype in women with lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) who developed subsequent ipsilateral invasive breast cancers.
Methods
Patients who underwent surveillance for classical LCIS (1994–2007) and those followed after lumpectomy ± radiation for DCIS (1991–2004) who developed subsequent ipsilateral invasive cancers and had available tissue blocks were included. ER/PR/HER2 surrogates were used for molecular subtype.
Results
Material was available for 27 patients with classical LCIS who developed ipsilateral invasive cancer (12 invasive ductal cancer IDC, 14 invasive lobular, 1 mixed), and 26 patients with DCIS (12 low-grade LG, 14 high-grade HG) who developed ipsilateral IDC. No difference in age at diagnosis or median time to invasive cancer existed between groups with LCIS and DCIS. When stratified by grade, 0 of 12 LG-DCIS developed LG-IDC (3 grade II; 9 grade III), and only 1 of 12 LCIS patients who developed IDC had LG-IDC. Thirteen (93%) patients with HG-DCIS developed HG-IDC. In contrast, molecular subtype was maintained in 23 of 27 (85%) cases of LCIS and in 18 of 26 (69%) cases of DCIS.
Conclusions
These data do not support a low-grade precursor pathway characterized by LCIS and LG-DCIS. ER/PR and HER2 status have a high rate of concordance between in situ and subsequent invasive lesions. Additional studies of metachronous in situ and invasive lesions are needed to better understand pathways of breast tumorigenesis.
Micro-Abstract There is a lack of predictive biomarkers that can help determine a subset of patients who might most benefit from treatment with heat shock protein 90 (HSP90) inhibitors. Results from ...this retrospective tissue analysis from advanced solid tumor patients (most with breast cancer) who were treated with various HSP90 inhibitors suggest that HER2 might be the only effective biomarker of sensitivity to HSP90 inhibitors.
The role of DNA ploidy in genomic instability of cancer cells and prognosis has been described in a number of studies. The role of the centrosome in cell cycle has also been reported.
In this study, ...we aimed to investigate the correlation between the centrosome and DNA ploidy in breast cancer in a search for a cytologic predictive and prognostic marker.
Cell prints were prepared from cell culture of mesothelial cells, fibroblast cell line MRC5 and breast cancer cell lines MCF7 and T47D. Indirect immunofluorescence was used with anti-γ-tubulin and centrosomes were quantified using a fluorescence microscope. DNA ploidy was scored with the DNA index analyzed by flow cytometry.
The normal mesothelial cells (94% of the cells with one detected centrosome) and MRC5 diploid cells (68% with two centrosomes) were used as quality controls. A correlation between the number of centrosomes and DNA ploidy was found in MCF7 cell lines (64% of the cells with a number of centrosomes ≥ 3). It was not observed in invasive breast cancer samples; however, the frequency of cells with centrosomes ≥ 3 was found to be slightly higher in DNA aneuploid samples than in DNA diploid samples (15% vs 13.3%).
Quantification of centrosome appears to be correlated to DNA ploidy in breast cancer cell lines and slightly associated to DNA aneuploidy in invasive breast cancer. Studies analyzing a larger number of samples as well as morphological abnormalities of the centrosome are needed.
This study aims to deepen the analysis of seed germination ecology and salinity tolerance of Sarcopoterium spinosum (Rosaceae).
Germination tests were conducted to evaluate the effect of the fruit’s ...spongy tissue and the intraspecific variability in seed germination among eight populations of the species on responses to light and total darkness, constant and alternating temperatures, salt stress and germination recovery. The effect of the presence of the spongy tissue varied among populations, with significant results for seed germination. For all populations, optimum germination temperatures were observed in the range of 10–20°C, indicating that S. spinosum and its germination in the field might occur preferably in the period between autumn and early spring. The high water availability due to rainfall during this period could be a considerable advantage for the seed germination of this species. Seeds of S. spinosum showed the ability to germinate in up to 250 mM NaCl in the substrate, and their ability to recover after salt exposure may be interpreted as adaptation to the coastal habitats in which they generally grow. These results give this species a halo‐tolerant character. Great inter‐population variability is detected in this study in several aspects, which indicated that the Mediterranean populations of S. spinosum differ considerably and are adapted to their local conditions. This study provides new information about S. spinosum seed ecology, which could help to preserve and apply effective conservation measures for this species, which in several areas of its distribution range is endangered.
Analysis of seed germination ecology and salinity tolerance of Sarcopoterium spinosum was executed. Germination tests were conducted to evaluate the effect of the fruit spongy tissue and the intraspecific variability on the seed germination. This study provides new information about the S. spinosum seed ecology.
Abstract
Highly cohesive silicone gel implants are advertised for aesthetic and safety advantages. Our case is the fourth report describing early implant rupture and contralateral migration of ...siliconoma. Despite the greater degree of gel cohesiveness, a continued vigilance for signs and symptoms of migration is highly recommended.
Detection of minor genetically distinct subpopulations within tumors is a key challenge in cancer genomics. Here we report STAR-FISH (Specific-To-Allele PCR – FISH), a novel method for the combined ...detection of single nucleotide and copy number alterations in single cells in intact archived tissues. Using this method, we assessed the clinical impact of changes in the frequency and topology of
PIK3CA
mutation and
HER2/ERBB2
amplification within HER2
+
breast cancer during neoadjuvant therapy. We found that the two genetic events are not always present within the same cell. Chemotherapy selects for
PIK3CA
mutant cells, a minor subpopulation in nearly all treatment-naïve samples, and modulates genetic diversity within tumors. Treatment-associated changes in spatial distribution of cellular genetic diversity correlated with poor long-term outcome following adjuvant trastuzumab therapy. Our findings support the use of
in situ
single-cell based methods in cancer genomics and imply that chemotherapy before HER2-targeted therapy may promote treatment resistance.
This article addresses the representation of forced and clandestine migration in some of Hassan Blasim's short stories within an interdisciplinary conceptual framework that brings together theories ...of biopolitics, ecocriticism, human rights discourse, heterotopia, and the aesthetics of "nightmare realism". Blasim's short stories offer new opportunities to address territoriality, life and truth at their limits in real and imagined sites where forest and border, human and non-human meet to suggest more-than-human futures for the paradoxical project of reclaiming human rights. By analysing Blasim's unique representational techniques, through which he mediates material and discursive violence within a combined biopolitical-ecological framework, the article also investigates the potentials and limitations of a more ecologically attuned perspective on freedom of movement and community, based on the claims of the environment rather than the nation.
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