Endochondral bone formation in toothless (osteopetrotic) rats: failures of chondrocyte patterning and type X collagen expression

The pacemaker of endochondral bone growth is cell division and hypertrophy of chondrocytes. The developmental stages of chondrocytes, characterized by the expression of collagen types II and X, are arranged in arrays across the growth zone. Mutations in collagen II and X genes as well as the absence of their gene products lead to different, altered patterns of chondrocyte stages which remain aligned across the growth plate (GP). Here we analyze GP of rats bearing the mutation toothless (tl) which, apart from bone defects, develop a progressive, severe chondrodystrophy during postnatal weeks 3 to 6. Mutant GP exhibited disorganized, non-aligned chondrocytes and mineralized metaphyseal bone but without cartilage mineralization or cartilaginous extensions into the metaphysis. Expression of mRNA coding for collagen types II (Col II) and X (Col X) was examined in the tibial GP by in situ hybridization. Mutant rats at 2 weeks exhibited Col II RNA expression and some hypertrophied chondrocytes (HC) but no Col X RNA was detected. By 3rd week, HC had largely disappeared from the central part of the mutant GP and Col II RNA expression was present but weak and in 2 separate bands. Peripherally the GP contained HC but without Col X RNA expression. This abnormal pattern was exacerbated by the fourth week. Bone mineralized but cartilage in the GP did not. These data suggest that the tl mutation involves a regulatory function for chondrocyte maturation, including Col X RNA synthesis and mineralization, and that the GP abnormalities are related to the Col X deficiency. The differences in patterning in the tl rat GP compared to direct Col X mutations may be explained by compensatory effects

Clear cell lesions of the head and neck: The spectrum of histological features

Objective: Estrogen receptor (ER) positive breast cancer (BC) can havean insidious course with disease-relapse decades after primary surgery.New analysis performed on archived formalin-fixed paraffin-embedded(FFPE) tissue are important for disease-management in late BC-relapseand an important tool in BC-research. However, although loss of immunoreactivityin tissue slides after sectioning has been shown, little isknown of the preservation of biomarker-expression in FFPE tumourblocks.We aim to investigate the quality of immunohistochemical(IHC) ER-evaluation in FFPE-tissue over time (1978–2000).Method: Tissue-microarrays from a Swedish multicenter cohort of 728patients with contralateral BC was used for ER IHC-evaluation. BC wasstudied in three periods (1958–1985, 1986–1993, 1994–2000), and retrospectiveER IHC-data was correlated to corresponding prospective ERcytosol-analysis performed on fresh BC-tissue.Results: The concordance between the original ER cytosol-analysis andthe new IHC was substantial (1978–1985: 82 %, (117/142), Kappa 0.52.1986–1993: 91 %, (194/213), Kappa 0.72. 1994–2000: 86 %, (187/218),Kappa 0.61). Discrepancies were mostly found for tumours with ERvaluesclose to cutoff for one or both of the methods.Conclusion: FFPE BC-tissue from the late 70s to millennium showspreserved ER-antigenicity up to 35 years later

CD44 isoforms are heterogeneously expressed in breast cancer and correlate with tumor subtypes and cancer stem cell markers

<p>Abstract</p> <p>Background</p> <p>The CD44 cell adhesion molecule is aberrantly expressed in many breast tumors and has been implicated in the metastatic process as well as in the putative cancer stem cell (CSC) compartment. We aimed to investigate potential associations between alternatively spliced isoforms of CD44 and CSCs as well as to various breast cancer biomarkers and molecular subtypes.</p> <p>Methods</p> <p>We used q-RT-PCR and exon-exon spanning assays to analyze the expression of four alternatively spliced CD44 isoforms as well as the total expression of CD44 in 187 breast tumors and 13 cell lines. ALDH1 protein expression was determined by IHC on TMA.</p> <p>Results</p> <p>Breast cancer cell lines showed a heterogeneous expression pattern of the CD44 isoforms, which shifted considerably when cells were grown as mammospheres. Tumors characterized as positive for the CD44⁺/CD24<it>^-</it>phenotype by immunohistochemistry were associated to all isoforms except the CD44 standard (CD44S) isoform, which lacks all variant exons. Conversely, tumors with strong expression of the CSC marker ALDH1 had elevated expression of CD44S. A high expression of the CD44v2-v10 isoform, which retain all variant exons, was correlated to positive steroid receptor status, low proliferation and luminal A subtype. The CD44v3-v10 isoform showed similar correlations, while high expression of CD44v8-v10 was correlated to positive EGFR, negative/low HER2 status and basal-like subtype. High expression of CD44S was associated with strong HER2 staining and also a subgroup of basal-like tumors. Unsupervised hierarchical cluster analysis of CD44 isoform expression data divided tumors into four main clusters, which showed significant correlations to molecular subtypes and differences in 10-year overall survival.</p> <p>Conclusions</p> <p>We demonstrate that individual CD44 isoforms can be associated to different breast cancer subtypes and clinical markers such as HER2, ER and PgR, which suggests involvement of CD44 splice variants in specific oncogenic signaling pathways. Efforts to link CD44 to CSCs and tumor progression should consider the expression of various CD44 isoforms.</p

Process evaluation of the Bridging the Age Gap in Breast Cancer decision support intervention cluster randomized trial [abstract only]

Aims/Objectives: Shared decision making on the choice of treatment for older women with breast cancer involves many factors. Comprehensive geriatric assessment (CGA) is recognised to have a role in older patients with cancer, but how this should be utilised is still debatable. A pilot study involving older women newly diagnosed with early operable primary breast cancer was conducted aiming to explore the potential value of CGA. Methods: Decision of primary treatment followed consultation with the clinical team and was not guided by any aspect of this study. CGA, using a validated cancer-specific tool from our collaborator, A Hurria, was conducted within 6 weeks after diagnosis, regardless of date of surgery/first treatment. A total of 178 female patients aged ≥70 years with a new diagnosis of early (stage 1 or 2; cT0-2, N0-1, M0) operable primary breast cancer proven histologically, were thus far recruited from three UK centres. Results: Among these 178 patients, 149 underwent primary surgery and 29 received non-surgical treatment (primary endocrine therapy (N=28) or radiotherapy (N=1)). CGA determined that increasing age (p=0.006), reduced independence with activities of daily living (ADLs) (p=0.001) and independent activities of daily living (IADLS) (p=0.001), increased number and severity of comorbidity (p=0.043), reduced Karnofsky performance status when rated both by the patient (p=0.001) and physician (p=0.003), were significantly related to non-surgical treatment within 6 weeks after diagnosis. Other CGA parameters measured which were not significant include number of daily medications, level of social support, level of social activity, cognition, number of falls, 'Timed up and go' score. Conclusions: The pilot study has confirmed that CGA may have value in assessing this cohort of patients. Generally, it appears that patients receiving non-surgical treatment are more frail than their counterparts undergoing surgery. The study is ongoing and has expanded to include an international centre

Molecular subtypes of breast cancer are associated with characteristic DNA methylation patterns

Introduction: Five different molecular subtypes of breast cancer have been identified through gene expression profiling. Each subtype has a characteristic expression pattern suggested to partly depend on cellular origin. We aimed to investigate whether the molecular subtypes also display distinct methylation profiles. Methods: We analysed methylation status of 807 cancer-related genes in 189 fresh frozen primary breast tumours and four normal breast tissue samples using an array-based methylation assay. Results: Unsupervised analysis revealed three groups of breast cancer with characteristic methylation patterns. The three groups were associated with the luminal A, luminal B and basal-like molecular subtypes of breast cancer, respectively, whereas cancers of the HER2-enriched and normal-like subtypes were distributed among the three groups. The methylation frequencies were significantly different between subtypes, with luminal B and basal-like tumours being most and least frequently methylated, respectively. Moreover, targets of the polycomb repressor complex in breast cancer and embryonic stem cells were more methylated in luminal B tumours than in other tumours. BRCA2-mutated tumours had a particularly high degree of methylation. Finally, by utilizing gene expression data, we observed that a large fraction of genes reported as having subtype-specific expression patterns might be regulated through methylation. Conclusions: We have found that breast cancers of the basal-like, luminal A and luminal B molecular subtypes harbour specific methylation profiles. Our results suggest that methylation may play an important role in the development of breast cancers

Comprehensive molecular comparison of BRCA1 hypermethylated and BRCA1 mutated triple negative breast cancers

Funder: The Governmental Funding for Young Clinical Researchers within the National Health Service (ALF) 2017-2019Funder: Shamik Mitra is financially supported by the funding received from the European Community’s Horizon 2020 Framework Program for Research and Innovation (H2020-MSCA-ITN-2014) under Grant Agreement no. 247634Funder: Vetenskapsrådet (Swedish Research Council); doi: https://doi.org/10.13039/501100004359Funder: The Governmental Funding within the National Health Service (ALF)Funder: - The Governmental Funding of Clinical Research within the National Health Service (ALF), grant nbr 2018/40612 - The Gustav V:s Jubilee Foundation (174271 and 187041) - The research foundation at Department of Oncology in LundAbstract: Homologous recombination deficiency (HRD) is a defining characteristic in BRCA-deficient breast tumors caused by genetic or epigenetic alterations in key pathway genes. We investigated the frequency of BRCA1 promoter hypermethylation in 237 triple-negative breast cancers (TNBCs) from a population-based study using reported whole genome and RNA sequencing data, complemented with analyses of genetic, epigenetic, transcriptomic and immune infiltration phenotypes. We demonstrate that BRCA1 promoter hypermethylation is twice as frequent as BRCA1 pathogenic variants in early-stage TNBC and that hypermethylated and mutated cases have similarly improved prognosis after adjuvant chemotherapy. BRCA1 hypermethylation confers an HRD, immune cell type, genome-wide DNA methylation, and transcriptional phenotype similar to TNBC tumors with BRCA1-inactivating variants, and it can be observed in matched peripheral blood of patients with tumor hypermethylation. Hypermethylation may be an early event in tumor development that progress along a common pathway with BRCA1-mutated disease, representing a promising DNA-based biomarker for early-stage TNBC

Promoting active learning in universities

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Genomic subtypes of breast cancer identified by array comparative genomic hybridization display distinct molecular and clinical characteristics

Abstract Introduction Breast cancer is a profoundly heterogeneous disease with respect to biologic and clinical behavior. Gene-expression profiling has been used to dissect this complexity and to stratify tumors into intrinsic gene-expression subtypes, associated with distinct biology, patient outcome, and genomic alterations. Additionally, breast tumors occurring in individuals with germline BRCA1 or BRCA2 mutations typically fall into distinct subtypes. Methods We applied global DNA copy number and gene-expression profiling in 359 breast tumors. All tumors were classified according to intrinsic gene-expression subtypes and included cases from genetically predisposed women. The Genomic Identification of Significant Targets in Cancer (GISTIC) algorithm was used to identify significant DNA copy-number aberrations and genomic subgroups of breast cancer. Results We identified 31 genomic regions that were highly amplified in > 1% of the 359 breast tumors. Several amplicons were found to co-occur, the 8p12 and 11q13.3 regions being the most frequent combination besides amplicons on the same chromosomal arm. Unsupervised hierarchical clustering with 133 significant GISTIC regions revealed six genomic subtypes, termed 17q12, basal-complex, luminal-simple, luminal-complex, amplifier, and mixed subtypes. Four of them had striking similarity to intrinsic gene-expression subtypes and showed associations to conventional tumor biomarkers and clinical outcome. However, luminal A-classified tumors were distributed in two main genomic subtypes, luminal-simple and luminal-complex, the former group having a better prognosis, whereas the latter group included also luminal B and the majority of BRCA2-mutated tumors. The basal-complex subtype displayed extensive genomic homogeneity and harbored the majority of BRCA1-mutated tumors. The 17q12 subtype comprised mostly HER2-amplified and HER2-enriched subtype tumors and had the worst prognosis. The amplifier and mixed subtypes contained tumors from all gene-expression subtypes, the former being enriched for 8p12-amplified cases, whereas the mixed subtype included many tumors with predominantly DNA copy-number losses and poor prognosis. Conclusions Global DNA copy-number analysis integrated with gene-expression data can be used to dissect the complexity of breast cancer. This revealed six genomic subtypes with different clinical behavior and a striking concordance to the intrinsic subtypes. These genomic subtypes may prove useful for understanding the mechanisms of tumor development and for prognostic and treatment prediction purposes

Engagement for quality development in higher education : a process for quality assurance of assessment

This paper reports on the design, development and evaluation of a novel process for quality assurance of assessments for entire educational programmes. The process was developed and tested by multidisciplinary teaching staff and consists of five phases: inventory, analyses, evaluation, planning change and realising change. The process for quality assurance was evaluated in three diverse programmes. The results show that the process forms a solid base for decisions on short-term as well as long-term quality improvements. It was also found to encourage the development of a quality culture and had an improving effect on the curriculum design, enhanced internal quality work and supported documentation for external quality assurance. The results show that the process has the capacity to engage and involve teachers and other internal stakeholders in the quality development of a range of educational programmes, promoting engaged change for improved quality in a higher education institution