An integrated cellular and molecular model of gastric neuroendocrine cancer evolution highlights therapeutic targets.

Gastric neuroendocrine carcinomas (G-NEC) are aggressive malignancies with poorly understood biology and a lack of disease models. Here, we use genome sequencing to characterize the genomic landscapes of human G-NEC and its histologic variants. We identify global and subtype-specific alterations and expose hitherto unappreciated gains of MYC family members in a large part of cases. Genetic engineering and lineage tracing in mice delineate a model of G-NEC evolution, which defines MYC as a critical driver and positions the cancer cell of origin to the neuroendocrine compartment. MYC-driven tumors have pronounced metastatic competence and display defined signaling addictions, as revealed by large-scale genetic and pharmacologic screening of cell lines and organoid resources. We create global maps of G-NEC dependencies, highlight critical vulnerabilities, and validate therapeutic targets, including candidates for clinical drug repurposing. Our study gives comprehensive insights into G-NEC biology.

ERR2 and ERR3 promote the development of gamma motor neuron functional properties required for proprioceptive movement control.

The ability of terrestrial vertebrates to effectively move on land is integrally linked to the diversification of motor neurons into types that generate muscle force (alpha motor neurons) and types that modulate muscle proprioception, a task that in mammals is chiefly mediated by gamma motor neurons. The diversification of motor neurons into alpha and gamma types and their respective contributions to movement control have been firmly established in the past 7 decades, while recent studies identified gene expression signatures linked to both motor neuron types. However, the mechanisms that promote the specification of gamma motor neurons and/or their unique properties remained unaddressed. Here, we found that upon selective loss of the orphan nuclear receptors ERR2 and ERR3 (also known as ERRß, ERRγ or NR3B2, NR3B3, respectively) in motor neurons in mice, morphologically distinguishable gamma motor neurons are generated but do not acquire characteristic functional properties necessary for regulating muscle proprioception, thus disrupting gait and precision movements. Complementary gain-of-function experiments in chick suggest that ERR2 and ERR3 could operate via transcriptional activation of neural activity modulators to promote a gamma motor neuron biophysical signature of low firing thresholds and high firing rates. Our work identifies a mechanism specifying gamma motor neuron functional properties essential for the regulation of proprioceptive movement control.

Functional hypoxia drives neuroplasticity and neurogenesis via brain erythropoietin.

Erythropoietin (EPO), named after its role in hematopoiesis, is also expressed in mammalian brain. In clinical settings, recombinant EPO treatment has revealed a remarkable improvement of cognition, but underlying mechanisms have remained obscure. Here, we show with a novel line of reporter mice that cognitive challenge induces local/endogenous hypoxia in hippocampal pyramidal neurons, hence enhancing expression of EPO and EPO receptor (EPOR). High-dose EPO administration, amplifying auto/paracrine EPO/EPOR signaling, prompts the emergence of new CA1 neurons and enhanced dendritic spine densities. Single-cell sequencing reveals rapid increase in newly differentiating neurons. Importantly, improved performance on complex running wheels after EPO is imitated by exposure to mild exogenous/inspiratory hypoxia. All these effects depend on neuronal expression of the Epor gene. This suggests a model of neuroplasticity in form of a fundamental regulatory circle, in which neuronal networks-challenged by cognitive tasks-drift into transient hypoxia, thereby triggering neuronal EPO/EPOR expression.

The landscape of human mutually exclusive splicing.

Mutually exclusive splicing of exons is a mechanism of functional gene and protein diversification with pivotal roles in organismal development and diseases such as Timothy syndrome, cardiomyopathy and cancer in humans. In order to obtain a first genomewide estimate of the extent and biological role of mutually exclusive splicing in humans, we predicted and subsequently validated mutually exclusive exons (MXEs) using 515 publically available RNA-Seq datasets. Here, we provide evidence for the expression of over 855 MXEs, 42% of which represent novel exons, increasing the annotated human mutually exclusive exome more than fivefold. The data provide strong evidence for the existence of large and multi-cluster MXEs in higher vertebrates and offer new insights into MXE evolution. More than 82% of the MXE clusters are conserved in mammals, and five clusters have homologous clusters in Drosophila Finally, MXEs are significantly enriched in pathogenic mutations and their spatio-temporal expression might predict human disease pathology.

Altered Ca2+ homeostasis induces Calpain-Cathepsin axis activation in sporadic Creutzfeldt-Jakob disease.

Sporadic Creutzfeldt-Jakob disease (sCJD) is the most prevalent form of human prion disease and it is characterized by the presence of neuronal loss, spongiform degeneration, chronic inflammation and the accumulation of misfolded and pathogenic prion protein (PrPSc). The molecular mechanisms underlying these alterations are largely unknown, but the presence of intracellular neuronal calcium (Ca2+) overload, a general feature in models of prion diseases, is suggested to play a key role in prion pathogenesis.Here we describe the presence of massive regulation of Ca2+ responsive genes in sCJD brain tissue, accompanied by two Ca2+-dependent processes: endoplasmic reticulum stress and the activation of the cysteine proteases Calpains 1/2. Pathogenic Calpain proteins activation in sCJD is linked to the cleavage of their cellular substrates, impaired autophagy and lysosomal damage, which is partially reversed by Calpain inhibition in a cellular prion model. Additionally, Calpain 1 treatment enhances seeding activity of PrPSc in a prion conversion assay. Neuronal lysosomal impairment caused by Calpain over activation leads to the release of the lysosomal protease Cathepsin S that in sCJD mainly localises in axons, although massive Cathepsin S overexpression is detected in microglial cells. Alterations in Ca2+ homeostasis and activation of Calpain-Cathepsin axis already occur at pre-clinical stages of the disease as detected in a humanized sCJD mouse model.Altogether our work indicates that unbalanced Calpain-Cathepsin activation is a relevant contributor to the pathogenesis of sCJD at multiple molecular levels and a potential target for therapeutic intervention.

An optimised phylogenetic method sheds more light on the main branching events of rhodopsin-like superfamily.

The comparative genomics between different rhodopsin-like family groups (α, ß, γ and δ) is not well studied. We used a combination of phylogenetic analysis and statistical genomic methods to compare rhodopsin-like family proteins in species likely symbolic of this family's evolutionary progression. For intra-cluster relationships, we applied mathematical optimisation to enhance the tree search produced by the neighbour joining method (NJ) and compared it with maximum likelihood (ML) method. To infer inter-clusters relationships, we used Needleman-Wunsch analysis (NW), HHsearch, ancestral sequence reconstruction and phylogenetic network analysis. Using this workflow, we were able to identify key evolutionary events in the rhodopsin-like family receptors. We found that α rhodopsin-like group gave rise to the ß group, while the γ rhodopsin-like group diverged from the ß group. We tracked the diversification of every cluster, revealing that fungal opsin is the most ancient member of the α group, while adenosine receptors could be the first member to diverge in the MECA (melanocortin, endothelial differentiation sphingolipid, cannabinoid, and adenosine receptors) subfamily and that histamine receptors could be the parent of the amines receptors, while hypocretin receptors might be the most ancient member of the ß group. SOG (somatostatin, opioid, galanin) receptors formed the most ancient members of the γ group. Our analysis indicated that basal receptors might be playing a role in early evolution of the nervous system. This is evident in Trichoplax adhaerens genome, where we located histamine receptors and adenosine receptors.

Coexisting mantle cell lymphoma and prostate adenocarcinoma.

Prostatic mantle cell lymphoma (MCL) is a very rare entity with only 5 reported cases in the literature. We report a case of coexisting MCL and prostate adenocarcinoma (PCa) in an elderly male and review the morphologic features of classic and rare prostatic MCL subtypes. Careful morphologic evaluation and immunohistochemical findings of positive CD5, CD20, and cyclin D1 and negative CD23 and CD3 can guide us to the diagnosis of MCL. Given the fact that transurethral resection of prostate is done quite routinely, this paper draws attention to the manner in which long standing bladder outlet obstruction and postbiopsy prostate specimens with dense lymphoid infiltration can masquerade as lymphoma. It highlights the importance of exercising care while reviewing prostate specimens with evidence of chronic prostatitis so as not to miss this rare neoplasm.

Automated Quantitative Analysis of p53, Cyclin D1, Ki67 and pERK Expression in Breast Carcinoma Does Not Differ from Expert Pathologist Scoring and Correlates with Clinico-Pathological Characteristics.

There is critical need for improved biomarker assessment platforms which integrate traditional pathological parameters (TNM stage, grade and ER/PR/HER2 status) with molecular profiling, to better define prognostic subgroups or systemic treatment response. One roadblock is the lack of semi-quantitative methods which reliably measure biomarker expression. Our study assesses reliability of automated immunohistochemistry (IHC) scoring compared to manual scoring of five selected biomarkers in a tissue microarray (TMA) of 63 human breast cancer cases, and correlates these markers with clinico-pathological data. TMA slides were scanned into an Ariol Imaging System, and histologic (H) scores (% positive tumor area x staining intensity 0-3) were calculated using trained algorithms. H scores for all five biomarkers concurred with pathologists' scores, based on Pearson correlation coefficients (0.80-0.90) for continuous data and Kappa statistics (0.55-0.92) for positive vs. negative stain. Using continuous data, significant association of pERK expression with absence of LVI (p = 0.005) and lymph node negativity (p = 0.002) was observed. p53 over-expression, characteristic of dysfunctional p53 in cancer, and Ki67 were associated with high grade (p = 0.032 and 0.0007, respectively). Cyclin D1 correlated inversely with ER/PR/HER2-ve (triple negative) tumors (p = 0.0002). Thus automated quantitation of immunostaining concurs with pathologists' scoring, and provides meaningful associations with clinico-pathological data.

Immunohistochemical Assessment of Expression of Centromere Protein-A (CENPA) in Human Invasive Breast Cancer.

Abnormal cell division leading to the gain or loss of entire chromosomes and consequent genetic instability is a hallmark of cancer. Centromere protein -A (CENPA) is a centromere-specific histone-H3-like variant gene involved in regulating chromosome segregation during cell division. CENPA is one of the genes included in some of the commercially available RNA based prognostic assays for breast cancer (BCa)-the 70 gene signature MammaPrint® and the five gene Molecular Grade Index (MGISM). Our aim was to assess the immunohistochemical (IHC) expression of CENPA in normal and malignant breast tissue. Clinically annotated triplicate core tissue microarrays of 63 invasive BCa and 20 normal breast samples were stained with a monoclonal antibody against CENPA and scored for percentage of visibly stained nuclei. Survival analyses with Kaplan-Meier (KM) estimate and Cox proportional hazards regression models were applied to assess the associations between CENPA expression and disease free survival (DFS). Average percentage of nuclei visibly stained with CENPA antibody was significantly higher (p = 0.02) in BCa than normal tissue. The 3-year DFS in tumors over-expressing CENPA (>50% stained nuclei) was 79% compared to 85% in low expression tumors ( 60.07; p = 0.06) within our small cohort. To the best of our knowledge, this is the first published report evaluating the implications of increased IHC expression of CENPA in paraffin embedded breast tissue samples. Our finding that increased CENPA expression may be associated with shorter DFS in BCa supports its exploration as a potential prognostic biomarker.

Progesterone receptor is a significant factor associated with clinical outcomes and effect of adjuvant tamoxifen therapy in breast cancer patients.

Estrogen receptor status in breast cancer is associated with response to hormonal therapy and clinical outcome. The additional value of progesterone receptor (PR) has remained controversial. We examine the value of PR for prognosis and response to tamoxifen on a population-based series of 4,046 invasive early stage breast cancer patients. Clinical information for age at diagnosis, stage, pathology, treatment and outcome was assembled for the study cohort; the median follow-up was 12.4 years. PR status was determined by immunohistochemistry using a rabbit monoclonal antibody on tissue microarrays built from breast tumor surgical excisions. Survival analyses, Kaplan-Meier functions and Cox proportional hazards regression models were applied to assess the associations between PR and breast cancer specific survival. Progesterone receptor was positive in 51% of all cases and 67% of estrogen receptor positive (ER+) cases. Survival analyses for both the whole cohort and ER+ cases given tamoxifen therapy showed that patients with PR+ tumors had 24% higher relative probability for breast cancer specific survival as compared to PR- patients, adjusted for ER, HER2, age at diagnosis, grade, tumor size, lymph node status and lymphovascular invasion covariates. Higher PR expression showed stronger association with patient survival. Log-likelihood ratio tests of multivariate Cox proportional hazards regression models demonstrated that PR was an independent statistically significant factor for breast cancer specific survival in both the whole cohort and among ER+ cases treated with tamoxifen. PR adds significant prognostic value in breast cancer beyond that obtained with estrogen receptor alone.

Ovarian carcinoma subtypes are different diseases: implications for biomarker studies.

BACKGROUND: Although it has long been appreciated that ovarian carcinoma subtypes (serous, clear cell, endometrioid, and mucinous) are associated with different natural histories, most ovarian carcinoma biomarker studies and current treatment protocols for women with this disease are not subtype specific. With the emergence of high-throughput molecular techniques, distinct pathogenetic pathways have been identified in these subtypes. We examined variation in biomarker expression rates between subtypes, and how this influences correlations between biomarker expression and stage at diagnosis or prognosis. METHODS AND FINDINGS: In this retrospective study we assessed the protein expression of 21 candidate tissue-based biomarkers (CA125, CRABP-II, EpCam, ER, F-Spondin, HE4, IGF2, K-Cadherin, Ki-67, KISS1, Matriptase, Mesothelin, MIF, MMP7, p21, p53, PAX8, PR, SLPI, TROP2, WT1) in a population-based cohort of 500 ovarian carcinomas that was collected over the period from 1984 to 2000. The expression of 20 of the 21 biomarkers differs significantly between subtypes, but does not vary across stage within each subtype. Survival analyses show that nine of the 21 biomarkers are prognostic indicators in the entire cohort but when analyzed by subtype only three remain prognostic indicators in the high-grade serous and none in the clear cell subtype. For example, tumor proliferation, as assessed by Ki-67 staining, varies markedly between different subtypes and is an unfavourable prognostic marker in the entire cohort (risk ratio [RR] 1.7, 95% confidence interval [CI] 1.2%-2.4%) but is not of prognostic significance within any subtype. Prognostic associations can even show an inverse correlation within the entire cohort, when compared to a specific subtype. For example, WT1 is more frequently expressed in high-grade serous carcinomas, an aggressive subtype, and is an unfavourable prognostic marker within the entire cohort of ovarian carcinomas (RR 1.7, 95% CI 1.2%-2.3%), but is a favourable prognostic marker within the high-grade serous subtype (RR 0.5, 95% CI 0.3%-0.8%). CONCLUSIONS: The association of biomarker expression with survival varies substantially between subtypes, and can easily be overlooked in whole cohort analyses. To avoid this effect, each subtype within a cohort should be analyzed discretely. Ovarian carcinoma subtypes are different diseases, and these differences should be reflected in clinical research study design and ultimately in the management of ovarian carcinoma.

Association of TMPRSS2-ERG gene fusion with clinical characteristics and outcomes: results from a population-based study of prostate cancer.

BACKGROUND: The presence of the TMPRSS2-ERG fusion gene in prostate tumors has recently been associated with an aggressive phenotype, as well as recurrence and death from prostate cancer. These associations suggest the hypothesis that the gene fusion may be used as a prognostic indicator for prostate cancer. METHODS: In this study, fluorescent in situ hybridization (FISH) assays were used to assess TMPRSS2-ERG fusion status in a group of 214 prostate cancer cases from two population-based studies. The FISH assays were designed to detect both fusion type (deletion vs. translocation) and the number of fusion copies (single vs. multiple). Genotyping of four ERG and one TMPRSS2 SNPs using germline DNA was also performed in a sample of the cases (n = 127). RESULTS: Of the 214 tumors scored for the TMPRSS2-ERG fusion, 64.5% were negative and 35.5% were positive for the fusion. Cases with the TMPRSS2-ERG fusion did not exhibit reduced prostate cancer survival (HR = 0.92, 95% CI = 0.22-3.93), nor was there a significant difference in cause-specific survival when stratifying by translocation or deletion (HR = 0.84, 95% CI = 0.23-3.12) or by the number of retained fusion copies (HR = 1.22, 95% CI = 0.45-3.34). However, evidence for reduced prostate cancer-specific survival was apparent in those cases whose tumor had multiple copies of the fusion. The variant T allele of the TMPRSS2 SNP, rs12329760, was positively associated with TMPRSS2-ERG fusion by translocation (p = 0.05) and with multiple copies of the gene fusion (p = 0.03). CONCLUSION: If replicated, the results presented here may provide insight into the mechanism by which the TMPRSS2-ERG gene fusion arises and also contribute to diagnostic evaluations for determining the subset of men who will go on to develop metastatic prostate cancer.

Suppression of VEGF secretion and changes in glioblastoma multiforme microenvironment by inhibition of integrin-linked kinase (ILK).

Integrin-linked kinase (ILK) was assesed as a therapeutic target in glioblastoma xenograft models through multiple endpoints including treatment related changes in the tumor microenvironment. Glioblastoma cell lines were tested in vitro for sensitivity toward the small-molecule inhibitors QLT0254 and QLT0267. Cell viability, cell cycle, and apoptosis were evaluated using MTT assay, flow cytometry, caspase activation, and DAPI staining. Western blotting and ELISA were used for protein analysis (ILK, PKB/Akt, VEGF, and HIF-1alpha). In vivo assessment of growth rate, cell proliferation, BrdUrd, blood vessel mass (CD31 labeling), vessel perfusion (Hoechst 33342), and hypoxia (EF-5) was done using U87MG glioblastoma xenografts in RAG2-M mice treated orally with QLT0267 (200 mg/kg q.d.). ILK inhibition in vitro with QLT0254 and QLT0267 resulted in decreased levels of phospho-PKB/Akt (Ser473), secreted VEGF, G2-M block, and apoptosis induction. Mice treated with QLT0267 exhibited significant delays in tumor growth (treated 213 mm3 versus control 549 mm3). In situ analysis of U87MG tumor cell proliferation from QLT0267-treated mice was significantly lower relative to untreated mice. Importantly, VEGF and HIF-1alpha expression decreased in QLT0267-treated tumors as did the percentage of blood vessel mass and numbers of Hoechst 33342 perfused tumor vessels compared with control tumors (35% versus 83%). ILK inhibition with novel small-molecule inhibitors leads to treatment-associated delays in tumor growth, decreased tumor angiogenesis, and functionality of tumor vasculature. The therapeutic effects of a selected ILK inhibitor (QLT0267) should be determined in the clinic in cancers that exhibit dysregulated ILK, such as PTEN-null glioblastomas.

Stromal mast cells in invasive breast cancer are a marker of favourable prognosis: a study of 4,444 cases.

PURPOSE: We have previously demonstrated in a pilot study of 348 invasive breast cancers that mast cell (MC) infiltrates within primary breast cancers are associated with a good prognosis. Our aim was to verify this finding in a larger cohort of invasive breast cancer patients and examine the relationship between the presence of MCs and other clinical and pathological features. EXPERIMENTAL DESIGN: Clinically annotated tissue microarrays (TMAs) containing 4,444 cases were constructed and stained with c-Kit (CD-117) using standard immunoperoxidase techniques to identify and quantify MCs. For statistical analysis, we applied a split-sample validation technique. Breast cancer specific survival was analyzed by Kaplan-Meier [KM] method and log rank test was used to compare survival curves. RESULTS: Survival analysis by KM method showed that the presence of stromal MCs was a favourable prognostic factor in the training set (P = 0.001), and the validation set group (P = 0.006). X-tile plot generated to define the optimal number of MCs showed that the presence of any number of stromal MCs predicted good prognosis. Multivariate analysis showed that the MC effect in the training set (Hazard ratio [HR] = 0.804, 95% Confidence interval [CI], 0.653-0.991, P = 0.041) and validation set analysis (HR = 0.846, 95% CI, 0.683-1.049, P = 0.128) was independent of age, tumor grade, tumor size, lymph node, ER and Her2 status. CONCLUSIONS: This study concludes that stromal MC infiltration in invasive breast cancer is an independent good prognostic marker and reiterates the critical role of local inflammatory responses in breast cancer progression.

Cell cycle regulators show diagnostic and prognostic utility for differentiated thyroid cancer.

BACKGROUND: Differentiated thyroid cancer (DTC) generally has a favorable outcome, but some patients develop local recurrence and/or distant metastases and ultimately die of their disease. Molecular markers that accurately predict tumor behavior are lacking. This study's aim was to ascertain the role of cell cycle regulators in predicting malignant histology and tumor behavior in DTC. METHODS: Tissue microarrays consisting of 100 benign and 105 malignant thyroid lesions, plus 24 lymph node samples, were stained for p16, p21, p27, p53, p57, p63, cyclin D1, cyclin E, and mdm2. Statistical analysis was used to compare the expression of the markers in benign versus DTC lesions and correlate their expression with clinicopathologic characteristics. RESULTS: p16, p21, cyclin D1, and cyclin E showed significantly (P < .001) increased expression in DTCs compared with benign thyroid lesions (54.7% vs. 5%, 71.7% vs. 38%, 87.1% vs. 45.7%, and 72.3% vs. 37.4%, respectively). There was no significant difference in expression between benign lesions and DTC for the remaining markers. p16 expression correlated significantly with extrathyroidal tumor extension (P = .02) and the presence of cancer in lymph nodes (P = .03). A total of 73% vs. 45% of the cancers of patients with and without lymph node involvement, respectively, stained positive for p16 (P = .01). CONCLUSIONS: There is a statistically significant difference in the expression of p16, p21, cyclin D1, and cyclin E between DTCs and benign thyroid lesions, and p16 expression correlates with clinicopathologic variables predicting poor outcomes for DTC. These results suggest that evaluation of cell cycle derangement in thyroid tumors may serve as a useful tool for both DTC diagnosis and prognosis.

Identification of molecular markers altered during transformation of differentiated into anaplastic thyroid carcinoma.

HYPOTHESIS: A change in tumor expression profile will be observed during the transformation of differentiated into anaplastic thyroid carcinoma. DESIGN: Cohort study. SETTING: Population-based sample (British Columbia). PATIENTS: Sequential archival cases of anaplastic thyroid cancer with an adjacent associated differentiated thyroid cancer focus, and with available paraffin blocks, that had been diagnosed and treated in British Columbia during a 20-year period (12 cases; January 1, 1984, through December 31, 2004) were identified through the provincial tumor registry for tissue microarray construction. MAIN OUTCOME MEASURE: Significant associations between marker staining and tumor pathologic diagnosis (differentiated vs anaplastic) were determined with contingency table and marginal homogeneity tests. A classifier algorithm was also used to identify useful and important molecular classifiers. RESULTS: Overall, there were 3 up-regulated and 5 down-regulated markers when comparing the anaplastic carcinoma with associated differentiated thyroid cancers. Contingency table statistics identified 5 markers (thyroglobulin, Bcl-2, MIB-1, E-cadherin, and p53) to be significantly differentially expressed by the anaplastic and differentiated tumor foci. These 5 markers and 3 others (beta-catenin, topoisomerase II-alpha, and vascular endothelial growth factor) were significant when evaluated using the marginal homogeneity test. Clustering and classification analysis based on these same 8 markers readily separated differentiated and anaplastic thyroid tumors with a high degree of accuracy. CONCLUSION: The markers we observed to change during thyroid tumor progression may not only show promise as molecular diagnostic or prognostic tools but also warrant further study as potential targets for treatment of disease.

Elevated expression of DecR1 impairs ErbB2/Neu-induced mammary tumor development.

Tumor cells utilize glucose as a primary energy source and require ongoing lipid biosynthesis for growth. Expression of DecR1, an auxiliary enzyme in the fatty acid beta-oxidation pathway, is significantly diminished in numerous spontaneous mammary tumor models and in primary human breast cancer. Moreover, ectopic expression of DecR1 in ErbB2/Neu-induced mammary tumor cells is sufficient to reduce levels of ErbB2/Neu expression and impair mammary tumor outgrowth. This correlates with a decreased proliferative index and reduced rates of de novo fatty acid synthesis in DecR1-expressing breast cancer cells. Although DecR1 expression does not affect glucose uptake in ErbB2/Neu-transformed cells, sustained expression of DecR1 protects mammary tumor cells from apoptotic cell death following glucose withdrawal. Moreover, expression of catalytically impaired DecR1 mutants in Neu-transformed breast cancer cells restored Neu expression levels and increased mammary tumorigenesis in vivo. These results argue that DecR1 is sufficient to limit breast cancer cell proliferation through its ability to limit the extent of oncogene expression and reduce steady-state levels of de novo fatty acid synthesis. Furthermore, DecR1-mediated suppression of tumorigenesis can be uncoupled from its effects on Neu expression. Thus, while downregulation of Neu expression may contribute to DecR1-mediated tumor suppression in certain cell types, this is not an obligate event in all Neu-transformed breast cancer cells.

Frequency of the TMPRSS2:ERG gene fusion is increased in moderate to poorly differentiated prostate cancers.

BACKGROUND: Recent reports indicate that prostate cancers (CaP) frequently over-express the potential oncogenes, ERG or ETV1. Many cases have chromosomal rearrangements leading to the fusion of the 5' end of the androgen-regulated serine protease TMPRSS2 (21q22.2) to the 3' end of either ERG (21q22.3) or ETV1 (7p21.3). The consequence of these rearrangements is aberrant androgen receptor-driven expression of the potential oncogenes, ETV1 or ERG. AIM: To determine the frequency of rearrangements involving TMPRSS2, ERG, or ETV1 genes in CaP of varying Gleason grades through fluorescence in situ hybridisation (FISH) on CaP tissue microarrays (TMAs). METHODS: Two independent assays, a TMPRSS2 break-apart assay and a three-colour gene fusion FISH assay were applied to TMAs. FISH positive cases were confirmed by reverse transcriptase (RT) PCR and DNA sequence analysis. RESULTS: A total of 106/196 (54.1%) cases were analysed by FISH. None of the five benign prostatic hyperplasia cases analysed exhibited these gene rearrangements. TMPRSS2:ERG fusion was found more frequently in moderate to poorly differentiated tumours (35/86, 40.7%) than in well differentiated tumours (1/15, 6.7%, p = 0.017). TMPRSS2:ETV1 gene fusions were not detected in any of the cases tested. TMPRSS2:ERG fusion product was verified by RT-PCR followed by DNA sequencing in 7/7 randomly selected positive cases analysed. CONCLUSION: This study indicates that TMPRSS2:ERG gene rearrangements in CaP may be used as a diagnostic tool to identify prognostically relevant sub-classifications of these cancers.

Anaplastic thyroid carcinoma: expression profile of targets for therapy offers new insights for disease treatment.

BACKGROUND: Anaplastic thyroid cancer is an endocrine malignancy. Its rare and rapidly lethal disease course has made it challenging to study. Little is known regarding the expression by anaplastic tumors of molecular targets for new human anticancer agents that have been studied in the preclinical or clinical setting. The objective of this work was to evaluate the expression profile of anaplastic thyroid tumors for molecular targets for treatment. METHODS: Of the 94 cases of anaplastic thyroid cancers diagnosed and treated in British Columbia, Canada over a 20-year period (1984-2004), 32 cases (34%) had adequate archival tissue available for evaluation. A tissue microarray was constructed from these anaplastic thyroid tumors and immunohistochemistry was utilized to evaluate expression of 31 molecular markers. The markers evaluated were: epidermal growth factor receptor (EGFR), HER2, HER3, HER4, ER, PR, uPA-R, clusterin, E-cadherin, beta-catenin, AMF-R, c-kit, VEGF, ILK, aurora A, aurora B, aurora C, RET, CA-IX, IGF1-R, p53, MDM2, p21, Bcl-2, cyclin D1, cyclin E, p27, calcitonin, MIB-1, TTF-1, and thyroglobulin. RESULTS: A single tumor with strong calcitonin expression was identified as a poorly differentiated medullary carcinoma and excluded from the study cohort. The mean age of the anaplastic cohort was 66 years; 16 patients (51%) were females, and the median patient survival was 23 weeks. A wide range in molecular marker expression was observed by the anaplastic thyroid cancer tumors (0-100%). The therapeutic targets most frequently and most strongly overexpressed by the anaplastic tumors were: beta-catenin (41%), aurora A (41%), cyclin E (67%), cyclin D1 (77%), and EGFR (84%). CONCLUSIONS: Anaplastic thyroid tumors exhibit considerable derangement of their cell cycle and multiple signal transduction pathways that leads to uncontrolled cellular proliferation and the development of genomic instability. This report is the first to comprehensively evaluate a panel of molecular targets for therapy of anaplastic thyroid cancer and supports the development of clinical trials with agents such as cetuximab, small-molecule tyrosine kinase inhibitors, and aurora kinase inhibitors, which may offer new hope for individuals diagnosed with this fatal thyroid malignancy.

Derangement of the E-cadherin/catenin complex is involved in transformation of differentiated to anaplastic thyroid carcinoma.

BACKGROUND: Anaplastic thyroid cancer arises, or transforms, from pre-existing differentiated thyroid cancer. E-cadherin functions as a cell-cell adhesion molecule that complexes with catenin proteins for function. The objective of this study was to evaluate the change in E-cadherin/beta-catenin expression in the transformation of differentiated to anaplastic thyroid carcinoma. METHODS: A tissue microarray was constructed from 12 anaplastic thyroid tumors and their adjacent associated differentiated foci. Immunohistochemistry was used to evaluate tumor expression of E-cadherin and beta-catenin. RESULTS: There was decreased expression of E-cadherin and beta-catenin by the anaplastic tumors when compared with the differentiated thyroid tumors from which they evolved. The expression of E-cadherin and beta-catenin was 92% and 67%, respectively, by the differentiated thyroid carcinoma, and 17% and 50%, respectively, by the anaplastic tumors. CONCLUSIONS: This report shows that derangement of the E-cadherin/catenin complex is associated with the transformation of differentiated into anaplastic thyroid carcinoma.