Biochemical markers are applied in gastroenteropancreatic neuroendocrine tumours (GEP-NETs) for diagnostic, prognostic or predictive purposes. Chromogranin A is the most important general marker and it is recommended to be measured in every patient with a suspected NET, whereas Neuron Specific Enolase is elevated mainly in poorly differentiated NETs. Pancreatic Polypeptide is used in the diagnosis of pancreatic non-functioning NETs, whereas Chorionic Gonadotrophin has an adjunctive role. In the case of functioning tumours, specific markers should be sought and monitored during follow up. Endogenous hyperinsulinemia is suggested in the presence of non-suppressible insulin and proinsulin levels during hypoglycemia, whereas high fasting or stimulated gastrin levels along with elevated gastric acid output are diagnostic for the Zollinger-Ellison syndrome. Glucagon, vasoactive intestinal polypeptide (VIP) and somatostatin are markers for glucagonoma, VIP-oma and somatostatinoma syndromes respectively. In case of ectopic paraneoplastic syndrome, the relevant hormone serves as a diagnostic and prognostic marker.

OBJECTIVE

To study the epidemiologic changes of gastroenteropancreatic neuroendocrine tumors (GEP-NET) in Germany, we analyzed two time periods 1976-1988 and 1998-2006.

METHODS

We evaluated epidemiological data of GEP-NET from the former East German National Cancer Registry (DDR Krebsregister, 1976-1988) and its successor, the Joint Cancer Registry (GKR, 1998-2006), which was founded after German reunification. Due to a particularly substantial database the epidemiological data from the federal states of Mecklenburg-Western Pomerania, Saxony, Brandenburg and Thuringia, covering a population of more than 10.8 million people, were analyzed. Survival probabilities were calculated using life table analysis. In addition, GEP-NET patients were evaluated for one or more second (non-GEP-NET) primary malignancies.

RESULTS

A total of 2821 GEP neuroendocrine neoplasms were identified in the two registries. The overall incidence increased significantly between 1976 and 2006 from 0.31 (per 100.000 inhabitants per year) to 2.27 for men and from 0.57 to 2.38 for women. In the later period studied (2004-2006), the small intestine was the most common site. Neuroendocrine (NE) neoplasms of the small intestine showed the largest absolute increase in incidence, while rectal NE neoplasms exhibited the greatest relative increase. Only the incidence of appendiceal NET in women showed little change between 1976 and 2006. Overall survival of patients varied for sex, tumor site and the two periods studied but improved significantly over time. Interestingly, about 20% of the GEP-NET patients developed one or more second malignancies. Their most common location was the gastrointestinal tract. GEP-NET patients without second malignancies fared better than those with one or more of them.

CONCLUSIONS

The number of detected GEP-NET increased about 5-fold in Germany between 1976 and 2006. At the same time, their anatomic distribution changed, and the survival of GEP-NET patients improved significantly. Second malignancies are common and influence the overall survival of GEP-NET patients. Thus, GEP-NET warrant our attention as well as intensive research on their tumorigenesis.

OBJECTIVE

The role of the Ki-67 tumour proliferation index (PI) in predicting the efficacy of peptide receptor radionuclide therapy (PRRT) in gastroenteropancreatic tumours (GEP-NET) remains undetermined. This single-centre analysis focused on the potential therapeutic impact of this immunohistochemical parameter.

METHODS

A total of 81 consecutive GEP-NET patients treated with (177)Lu-DOTA-octreotate (mean activity of 7.9 GBq per cycle, usually four treatment cycles at standard intervals of 3 months) were retrospectively analysed. Both an evaluable PI and tumour response (modified SWOG criteria) were required for patient inclusion.

RESULTS

Response of tumours with a PI of ≤20% (partial response 40%, minor response 15%, stable disease 34%, progressive disease 11%) was comparable in all PI subsets, including those with a PI of 20%. However, G3 tumours (PI>> 20%) showed progression in 71% of patients.

CONCLUSIONS

Response to PRRT is consistent over the PI range of ≤20% (G1 + G2). Contrary to preliminary previous suggestions, a PI of 15% or 20% should not preclude candidates from somatostatin receptor-targeted radiotherapy.

This study explores the relationship between the normalized difference vegetation index (NDVI), aboveground plant biomass, and ecosystem C fluxes including gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem production. We measured NDVI across long-term experimental treatments in wet sedge tundra at the Toolik Lake LTER site, in northern Alaska. Over 13 years, N and P were applied in factorial experiments (N, P and N + P), air temperature was increased using greenhouses with and without N + P fertilizer, and light intensity (photosynthetically active photon flux density) was reduced by 50% using shade cloth. Within each treatment plot, NDVI, aboveground biomass and whole-system CO(2) flux measurements were made at the same sampling points during the peak-growing season of 2001. We found that across all treatments, NDVI is correlated with aboveground biomass ( r(2)=0.84), GEP ( r(2)=0.75) and ER ( r(2)=0.71), providing a basis for linking remotely sensed NDVI to aboveground biomass and ecosystem carbon flux.

IL-6 signaling can be enhanced through transsignaling by the soluble IL-6 receptor (sIL-6r), allowing for the pleiotropic cytokine to affect cells it would not ordinarily have an effect on. Serum levels of sIL-6r can be used as an independent prognostic indicator and further stratify the GEP 70-gene low-risk group to identify an intermediate-risk group in multiple myeloma (MM). By analyzing more than 600 MM patients with ELISA, genotyping, and gene expression profiling tools, we show how the combination of 2 independent molecular genetic events is related to synergistic increases in sIL-6r levels. We also show that the rs2228145 minor allele is related to increased expression levels of an IL-6r splice variant that purportedly codes exclusively for a sIL-6r isoform. Together, the SNP rs2228145 minor allele C and amplification of chromosome 1q21 are significantly correlated to an increase in sIL-6r levels, which are associated with lower overall survival in 70-gene low-risk disease, and aid in identification of the intermediate-risk MM group.

BACKGROUND

Treatment options for patients with metastatic gastroenteropancreatic neuroendocrine tumours (GEP NETs) are still limited. We investigated the antitumour activity and safety profile of pazopanib--a multitarget drug with anti-angiogenic activity in patients with metastatic GEP NETs.

METHODS

This was a nonrandomised, open-labeled, single-center phase II study. Pazopanib was orally administered at a dose of 800 mg daily continuously with a 28-day cycle. The primary end point was an objective response rate according to Response Evaluation Criteria in Solid Tumors (RECIST). The secondary end points were progression-free survival (PFS), overall survival (OS) and safety. An independent review of objective response was planned. The trial is registered with ClinicalTrials.gov, NCT number 01099540. Correlative biomarker analyses were performed.

RESULTS

Between April 2010 and February 2012, a total of 37 patients were enrolled. Thirty-two percent of the enrolled patients had pancreatic primary and 22% of the patients had colorectal primary NETs. This phase II study demonstrated an objective response rate of 18.9% (7 of the 37, 95% CI 8.0-35.2) and a disease control rate (CR+confirmed PR+stable disease) of 75.7% (28 of the 37, 95% CI, 58.8-88.2) in metastatic GEP NETs. The independent review demonstrated a higher overall response rate of 24.3% (95% CI, 11.8-41.2%) with nine confirmed PRs.

CONCLUSIONS

Pazopanib showed a comparable efficacy to other targeted agents not only in pancreatic NETs but also in NETs originating from gastrointestinal (GI) tract.

Myoblast fusion is an essential step during myoblast differentiation that remains poorly understood. M-cadherin-dependent pathways that signal through Rac1 GTPase activation via the Rho-guanine nucleotide exchange factor (GEF) Trio are important for myoblast fusion. The ADP-ribosylation factor (ARF)6 GTPase has been shown to bind to Trio and to regulate Rac1 activity. Moreover, Loner/GEP(100)/BRAG2, a GEF of ARF6, has been involved in mammalian and Drosophila myoblast fusion, but the specific role of ARF6 has been not fully analyzed. Here, we show that ARF6 activity is increased at the time of myoblast fusion and is required for its implementation in mouse C2C12 myoblasts. Specifically, at the onset of myoblast fusion, ARF6 is associated with the multiproteic complex that contains M-cadherin, Trio, and Rac1 and accumulates at sites of myoblast fusion. ARF6 silencing inhibits the association of Trio and Rac1 with M-cadherin. Moreover, we demonstrate that ARF6 regulates myoblast fusion through phospholipase D (PLD) activation and phosphatidylinositol 4,5-bis-phosphate production. Together, these data indicate that ARF6 is a critical regulator of C2C12 myoblast fusion and participates in the regulation of PLD activities that trigger both phospholipids production and actin cytoskeleton reorganization at fusion sites.

BACKGROUND

Although TRIzol is widely used for preservation and isolation of RNA, there is suspicion that prolonged sample storage in TRIzol may affect array-based gene expression profiling (GEP) through premature termination during reverse transcription.

METHODS

GEP on Illumina arrays compared paired aliquots (cryopreserved or stored in TRIzol) of primary samples of multiple myeloma (MM) and acute myeloid leukemia (AML). Data were analyzed at the "probe level" (a single consensus value) or "bead level" (multiple measurements provided by individual beads).

RESULTS

TRIzol storage does not affect standard probe-level comparisons between sample groups: different preservation methods did not generate differentially expressed probes (DEP) within MM or AML sample groups, or substantially affect the many DEPs distinguishing between these groups. Differences were found by gene set enrichment analysis, but these were dismissible because of instability with permutation of sample labels, unbalanced restriction to TRIzol aliquots, inconsistency between MM and AML groups, and lack of biological plausibility. Bead-level comparisons found many DEPs within sample pairs, but most (73%) were <2-fold changed. There was no consistent evidence that TRIzol causes premature reverse transcription termination. Instead, a subset of DEPs were systematically due to increased signals in TRIzol-preserved samples from probes near the 5' end of transcripts, suggesting better mRNA preservation with TRIzol.

CONCLUSIONS

TRIzol preserves RNA quality well, without a deleterious effect on GEP. Samples stored frozen with and without TRIzol may be compared by GEP with only minor concern for systematic artifacts.

CONCLUSIONS

The standard practice of prolonged sample storage in TRIzol is suitable for GEP.

BACKGROUND

Gene expression profiling of whole blood may be useful for monitoring toxicological exposure and for diagnosis and monitoring of various diseases. Several methods are available that can be used to transport, store, and extract RNA from whole blood, but it is not clear which procedures alter results. In addition, characterization of interindividual and sex-based variation in gene expression is needed to understand sources and extent of variability.

METHODS

Whole blood was obtained from adult male and female volunteers (n = 42) and stored at various temperatures for various lengths of time. RNA was isolated and RNA quality analyzed. Affymetrix GeneChips (n = 23) were used to characterize gene expression profiles (GEPs) and to determine the effects on GEP of storage conditions, extraction techniques, types of GeneChip, or donor sex. Hierarchical clustering and principal component analysis were used to assess interindividual differences. Regression analysis was used to assess the relative impact of the studied variables.

RESULTS

Storage of blood samples for >1 week at 4 degrees C diminished subsequent RNA quality. Interindividual GEP differences were seen, but larger effects were observed related to RNA extraction technique, GeneChip, and donor sex. The relative importance of the variables was as follows: storage < genechip < extraction technique < donor sex.

CONCLUSIONS

Sample storage and extraction methods and interindividual differences, particularly donor sex, affect GEP of human whole blood.

Rodioimmunoassayable somatostatin (SRIF) was found in acid ethanol extracts from various parts of the gastro-entero-pancreatic (GEP) endocrine system in reptiles, amphibians, teleost bony fish, cartilaginous fish, and jawless fish, as well as in a deuterostomian invertebrate, the tunicate, Ciona intestinalis. The cellular sites could, as a rule, be easily visualized light-microscopically by the peroxidase-anti-peroxidase (PAP) immunocytochemical procedure, using guinea-pig and rabbit antisera against synthetic SRIF. The standard Hellerström-Hellman technique, used to detect argyrophi SRIF-storing D cells, failed to visualize the SRIF cells in teh GEP endocrine system of the tumicate and of the jaw-less fish. Moreover, the results comfirmed the previous description that this technique only exceptionally (and sometimes only after further modifications) gave positive results when applied to the GEP endocrine system of bony fish, amphibians, and reptiles. In cartilaginous fish, however, it worked adequately and confirmed the radio-immunological and immunocytochemical observations. In the mucosa of the alimentary tract and in the parenchyma of its associated glands of one echinoderm and two pelecypod molluscs and one crustacean arthropod no sgns of the occurrence of SRIF-storing cells were observed using the three correlated procedures. In several of these tissues, signs of the occurrence of insulin-producing cells had perviously been observed. Thus, SRIF seems to appear at a later evolutionary stage than insulin. The principal islets (Brockmann corpusles) of the marine teleost fish, Cottus scorpius, had the highest concentrations of radioimmunoassayable SRIF of all the GEP organs and tissues investigated, viz. about 200 ng/mg wet weight. Nevertheless, it was only 1/5 of the actual insulin content.

Response rates to cytotoxics in gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) vary; recent trials demonstrated lack of objective response rates in up to 70% of patients. Identification of predictive therapeutic biomarkers would be beneficial in the treatment of GEP. Selected markers with known or suspected capability of predicting response to cytotoxics or prognosis (Ki-67, p53, multidrug resistance protein-1 (MDR1), Akt, thymidylate synthase (TS), phosphatase and tensin homolog (PTEN), CA9, cluster of differentiation 34 (CD34), vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1, mismatch repair gene - human mutL homolog 1 (hLMH1), and Bcl-2) were analyzed using immunohistochemisrtry in 60 treatment-naive patients receiving chemotherapy (n=46) or chemoembolization (n=14) for inoperable advanced and/or metastatic GEP and correlated with prognosis (survival and response rates). Therapy included systemic chemotherapy with streptozotocin (n=28), doxorubicin (n=14), 5-fluorouracil (n=18), and etoposide/cisplatinum (n=16), or chemoembolization (streptozotocin, 9; doxorubicin, 5). Factors associated with overall survival in the entire cohort were Ki-67, P<0.001; tumor grade, P<0.001; tumor differentiation, P<0.001; CA9, P=0.004; Akt, P=0.01; HIF-1, P<0.001; p53, P<0.0001; and hMLH1, P=0.005. Markers associated with treatment response included overall group: Akt and PTEN (P=0.05 and 0.05 respectively); streptozotocin: Akt (P=0.07), TS (P=0.02), and PTEN (P=0.017); doxorubicin: Ki-67 (P=0.05), Akt (P=0.06), and CA9 (P=0.02). At multivariate analysis, Akt was significantly associated with a nonresponse to therapy (objective response (OR): 0.2 (0.05-0.8)). For patients receiving only systemic chemotherapy (n=46), PTEN (0.04) and hLMH1 (0.03) were correlated with treatment response and for individual molecules were streptozotocin: PTEN (P=0.008) and hLMH1 (0.07); doxorubicin: Akt (P=0.09), CA9 (P=0.09), and hLMH1 (P=0.09). These results demonstrate a number of new prognostic biomarkers in GEP-NET, and in addition, response to chemotherapy was correlated with a simple panel of selected markers (such as CA9, Akt, PTEN, TS, and hLMH1).

The Rab3 small G protein family consists of four members, Rab3A, -3B, -3C, and -3D. Of these members, Rab3A regulates Ca(2+)-dependent neurotransmitter release. These small G proteins are activated by Rab3 GDP/GTP exchange protein (Rab3 GEP). To determine the function of Rab3 GEP during neurotransmitter release, we have knocked out Rab3 GEP in mice. Rab3 GEP-/- mice developed normally but died immediately after birth. Embryos at E18.5 showed no evoked action potentials of the diaphragm and gastrocnemius muscles in response to electrical stimulation of the phrenic and sciatic nerves, respectively. In contrast, axonal conduction of the spinal cord and the phrenic nerve was not impaired. Total numbers of synaptic vesicles, especially those docked at the presynaptic plasma membrane, were reduced at the neuromuscular junction approximately 10-fold compared with controls, whereas postsynaptic structures and functions appeared normal. Thus, Rab3 GEP is essential for neurotransmitter release and probably for formation and trafficking of the synaptic vesicles.

Classification of diffuse large B-cell lymphoma (DLBCL) into cell-of-origin (COO) subtypes based on gene expression profiles has well-established prognostic value. These subtypes, termed germinal center B cell (GCB) and activated B cell (ABC) also have different genetic alterations and overexpression of different pathways that may serve as therapeutic targets. Thus, accurate classification is essential for analysis of clinical trial results and planning new trials by using targeted agents. The current standard for COO classification uses gene expression profiling (GEP) of snap frozen tissues, and a Bayesian predictor algorithm. However, this is generally not feasible. In this study, we investigated whether the qNPA technique could be used for accurate classification of COO by using formalin-fixed, paraffin-embedded (FFPE) tissues. We analyzed expression levels of 14 genes in 121 cases of R-CHOP-treated DLBCL that had previously undergone GEP by using the Affymetrix U133 Plus 2.0 microarray and had matching FFPE blocks. Results were evaluated by using the previously published algorithm with a leave-one-out cross-validation approach. These results were compared with COO classification based on frozen tissue GEP profiles. For each case, a probability statistic was generated indicating the likelihood that the classification by using qNPA was accurate. When data were dichotomized into GCB or non-GCB, overall accuracy was 92%. The qNPA technique accurately categorized DLBCL into GCB and ABC subtypes, as defined by GEP. This approach is quantifiable, applicable to FFPE tissues with no technical failures, and has potential for significant impact on DLBCL research and clinical trial development.

Gastroenteropancreatic (GEP) endocrine tumors (ETs) are neoplasms showing different hormonal profiles and different clinical and prognostic features, which depend consistently on the site of origin. Histological features and general endocrine markers do not differentiate tumors in relation to their location, making it difficult to establish the site of origin of a GEP ET that has metastasized to the liver or lymph nodes. A site-specific marker would be particularly useful in the examination of small specimens where there is not sufficient material for an extensive study of the hormonal expression. CDX2 is a transcription factor that has been recently proposed as a marker of intestinal adenocarcinomas. Our aim was to evaluate the immunohistochemical expression of CDX2 in normal tissues and in 184 formalin-fixed and paraffin-embedded ETs to verify whether it could be used to identify intestinal ETs with a high degree of sensitivity and specificity. Of these cases, 154 were primary tumors (99 GEP and 55 non-GEP tumors), 101 were well-differentiated endocrine tumors, and 53 were poorly differentiated endocrine carcinomas (PDECs). Of the cases, 30 were metastases from differently located ETs. Nuclear CDX2 immunoreactivity was found in all EC-cells (serotonin-producing cells), in about 10% of G-cells (gastrin-producing cells), in about 30% of GIP-cells (gastric inhibitory peptide cells) and in a few motilin-positive cells of the normal intestinal mucosa, while other gastrointestinal endocrine cell types were CDX2 negative. All midgut EC-cell tumors, their metastases, and two of three pancreatic EC-cell ETs were diffusely and intensely CDX2 positive. The other GEP ETs, their metastases, as well as the non-GEP ETs, were all CDX2 negative, with the exception of four PDECs, five gastrinomas and one pheochromocytoma, which were only focally positive. We conclude that CDX2 may be considered a sensitive and specific marker of midgut EC-cells and EC-cell tumors, and its expression may be useful in the diagnosis of metastases from occult ETs.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of neoplasms arising from the diffuse neuroendocrine system. The incidence of GEP-NETs has increased markedly over the past 3 decades, probably as a result of trends in imaging and improvements in diagnosis. Advances in molecular biology have translated into an expansion of treatment options for patients with GEP-NETs. Somatostatin analogs, initially developed for control of hormonal syndromes, have recently been proven to inhibit tumor growth. Newer drugs, targeting angiogenesis and mammalian target of rapamycin (mTOR) pathways, have been approved for progressive pancreatic NETs; however, their role in nonpancreatic NETs remains controversial. Alkylating cytotoxic agents, such as streptozocin and temozolomide, play an important role in the treatment of pancreatic NETs, although estimated response rates vary widely and phase III data are lacking. During the next few years, randomized clinical trials are expected to provide more clarity regarding the role of radiolabeled somatostatin analogs. Predictive biomarkers that would allow for individualized selection of treatments are needed.

Lysophosphatidic acid (LPA), an agonist that activates specific G protein-coupled receptors, is present at an elevated concentration in the serum and ascitic fluid of ovarian cancer patients. Although the increased levels of LPA have been linked to the genesis and progression of different cancers including ovarian carcinomas, the specific signaling conduit utilized by LPA in promoting different aspects of oncogenic growth has not been identified. Here, we show that LPA stimulates both migration and proliferation of ovarian cancer cells. Using multiple approaches, we demonstrate that the stimulation of ovarian cancer cells with LPA results in a robust and statistically significant proliferative response. Our results also indicate that Gα(12), the gep proto-oncogene, which can be stimulated by LPA via specific LPA receptors, is overtly activated in a large array of ovarian cancer cells. We further establish that LPA stimulates the rapid activation of Gα(12) in SKOV-3 cells and the expression of CT12, an inhibitory minigene of Gα(12) that disrupts LPAR-Gα(12) interaction and potently inhibits such activation. Using this inhibitory molecule as well as the shRNA approach, we show that the inhibition of Gα(12) or silencing of its expression drastically and significantly attenuates LPA-mediated proliferation of ovarian cancer cell lines such as SKOV3, Hey, and OVCAR-3. Together with our findings that the silencing of Gα(12) does not have any significant effect on LPA-mediated migratory response of SKOV3 cells, our results point to a critical role for LPA-LPAR-Gα(12) signaling in ovarian cancer cell proliferation and not in migration. Thus, results presented here for the first time demonstrate that the gep proto-oncogene forms a specific node in LPA-LPAR-mediated mitogenic signaling in ovarian cancer cells.

BACKGROUND

Membrane-associated guanylate kinase (MAGUK) with inverted orientation (MAGI)-1/brain angiogenesis inhibitor 1-associated protein (BAP1), is a member of the MAGUK family that has multiple PDZ domains and interacts with many transmembrane proteins, including receptors and channels, through these domains. MAGI-1/BAP1 is ubiquitously expressed and localized at tight junctions in epithelial cells. It is an isoform of the neurone-specific synaptic scaffolding molecule (S-SCAM), which is known to interact with NMDA receptors and neuroligins. We have recently found that S-SCAM also interacts with a signalling molecule, a GDP/GTP exchange protein (GEP) that is specific for Rap1 small G protein, Rap GEP, which has also recently been referred to as RA-GEF/PDZ-GEFI/CNras-GEF. In this study, we have examined whether MAGI-1/BAP1 also interacts with and serves as a scaffolding molecule for Rap GEP at tight junctions in epithelial cells.

RESULTS

MAGI-1/BAP1 similarly interacted with Rap GEP in cell-free and intact cell systems. A Northern blot analysis revealed that Rap GEP was expressed in most tissues examined. However, neither postsynaptic density (PSD)-95/synapse-associated protein (SAP) 90 (another member of the MAGUK family) nor SAP97/human discs-large tumour suppressor gene product (another ubiquitously expressed MAGUK localizing to adherens junctions in epithelial cells and the isoform of PSD-95/SAP90) interacted with Rap GEP.

CONCLUSIONS

These results indicate that MAGI-1/BAP1 serves as a scaffolding molecule for Rap GEP at tight junctions in epithelial cells.

Metastatic dissemination is the most frequent cause of death of sporadic colorectal cancer (sCRC) patients. Genomic abnormalities which are potentially characteristic of such advanced stages of the disease are complex and so far, they have been poorly described and only partially understood. We evaluated the molecular heterogeneity of sCRC tumors based on simultaneous assessment of the overall GEP of both coding mRNA and non-coding RNA genes in primary sCRC tumor samples from 23 consecutive patients and their paired liver metastases. Liver metastases from the sCRC patients analyzed, systematically showed deregulated transcripts of those genes identified as also deregulated in their paired primary colorectal carcinomas. However, some transcripts were found to be specifically deregulated in liver metastases (vs. non-tumoral colorectal tissues) while expressed at normal levels in their primary tumors, reflecting either an increased genomic instability of metastatic cells or theiradaption to the liver microenvironment. Newly deregulated metastatic transcripts included overexpression of APOA1, HRG, UGT2B4, RBP4 and ADH4 mRNAS and the miR-3180-3p, miR-3197, miR-3178, miR-4793 and miR-4440 miRNAs, together with decreased expression of the IGKV1-39, IGKC, IGKV1-27, FABP4 and MYLK mRNAS and the miR-363, miR-1, miR-143, miR-27b and miR-28-5p miRNAs. Canonical pathways found to be specifically deregulated in liver metastatic samples included multiple genes related with intercellular adhesion and the metastatic processes (e.g., IGF1R, PIK3CA, PTEN and EGFR), endocytosis (e.g., the PDGFRA, SMAD2, ERBB3, PML and FGFR2), and the cell cycle (e.g., SMAD2, CCND2, E2F5 and MYC). Our results also highlighted the activation of genes associated with the TGFβ signaling pathway, -e.g. RHOA, SMAD2, SMAD4, SMAD5, SMAD6, BMPR1A, SMAD7 and MYC-, which thereby emerge as candidate genes to play an important role in CRC tumor metastasis.

Approximately 5-10% of neuroendocrine tumors (NETs) of the gastroenteropancreatic system (GEP) have a hereditary background. The known inherited syndromes include multiple endocrine neoplasia type 1, neurofibromatosis type 1, von Hippel-Lindau disease, and the tuberous sclerosis complex. This review discusses for each of these syndromes the: (1) involved genes and specific types of mutations, (2) disease prevalence and penetrance, (3) affected neuroendocrine tissues and related clinical syndromes, (4) special morphological features of NETs and their putative precursor lesions. In addition, GEP-NETs clustering in individual families or associated with other malignancies without known genetic background are discussed.

OBJECTIVE

Development of a good practice guideline to plan and perform scientifically robust evaluation studies in health informatics.

METHODS

Issues to be addressed in evaluation studies were identified and guidance drafted based on the evaluation literature and on experiences by key players. Successive drafts of the guideline were discussed in several rounds by an increasing number of experts during conferences and by e-mail. At a fairly early point the guideline was put up for comments on the web.

RESULTS

Sixty issues were identified that are of potential relevance for planning, implementation and execution of an evaluation study in the health informatics domain. These issues cover all phases of an evaluation study: Preliminary outline, study design, operationalization of methods, project planning, execution and completion of the evaluation study. Issues of risk management and project control as well as reporting and publication of the evaluation results are also addressed.

CONCLUSIONS

A comprehensive list of issues is presented as a guideline for good evaluation practice in health informatics (GEP-HI). The strengths and weaknesses of the guideline are discussed. Application of this guideline will support better handling of an evaluation study, potentially leading to a higher quality of evaluation studies. This guideline is an important step towards building stronger evidence and thus to progress towards evidence-based health informatics.

We introduce and validate a new precision oncology framework for the systematic prioritization of drugs targeting mechanistic tumor dependencies in individual patients. Compounds are prioritized on the basis of their ability to invert the concerted activity of master regulator proteins that mechanistically regulate tumor cell state, as assessed from systematic drug perturbation assays. We validated the approach on a cohort of 212 gastroenteropancreatic neuroendocrine tumors (GEP-NETs), a rare malignancy originating in the pancreas and gastrointestinal tract. The analysis identified several master regulator proteins, including key regulators of neuroendocrine lineage progenitor state and immunoevasion, whose role as critical tumor dependencies was experimentally confirmed. Transcriptome analysis of GEP-NET-derived cells, perturbed with a library of 107 compounds, identified the HDAC class I inhibitor entinostat as a potent inhibitor of master regulator activity for 42% of metastatic GEP-NET patients, abrogating tumor growth in vivo. This approach may thus complement current efforts in precision oncology.

Scintigraphy with somatostatin analogs is a sensitive method for the staging and therapeutic management of patients with endocrine gastroenteropancreatic (GEP) tumors. The aim of this study was to compare prospectively somatostatin receptor scintigraphy (SRS) using 111n-pentetreotide with bone scintigraphy using 99mTc-hydroxymethylene diphosphonate for the detection of bone metastases.

METHODS

One-hundred-forty-five patients with proven endocrine GEP tumors were investigated. Patients were classified according to the presence of bone metastases as indicated by CT, MRI or histologic data. Group I included 19 patients with confirmed bone metastases, and group II included 126 patients without bone metastases.

RESULTS

In group I, SRS was positive in all 19 patients with bone metastases, and bone scintigraphy was positive in 17 patients. Bone metastases were found to occur predominantly in patients with liver metastases. In group 11, 5 patients had recent bone surgery for fracture or arthritis. SRS showed bone uptake in 4 of these patients, and bone scanning showed abnormal uptake in 5. In 7 of the remaining 121 group II patients, SRS was negative and bone scanning showed abnormal bone uptake suggesting bone metastases. The detection of bone metastases was of major prognostic value, because 42% of group 1 patients died during a 2-y follow-up.

CONCLUSIONS

In patients with GEP tumors, the accuracy of SRS appears to be similar to that of bone scintigraphy for the detection of bone metastases.

OBJECTIVE

As circulating chromogranin A (CgA) has been claimed to be the best general neuroendocrine marker so far available, we evaluated the usefulness of CgA determination in the clinical assessment of patients with sporadic gastro-entero-pancreatic neuroendocrine tumors (GEP NETs) or multiple endocrine neoplasia type 1 (MEN 1).

METHODS

Plasma CgA levels were measured using a commercial enzyme-linked immunosorbent assay in 61 patients with sporadic GEP NET and in 25 with MEN 1 including 16 with GEP NET. Controls were 50 healthy volunteers, 46 patients with pituitary adenoma and 35 patients with primary hyperparathyroidism.

RESULTS

The cutoff value for CgA established in our healthy subjects (as mean+2 s.d.) was 20 U/l. CgA levels were above the normal range in 71/77 patients with sporadic or MEN 1-related GEP NETs (92%), in four out of nine MEN 1 patients without GEP NETs (44%), and only in 22/81 control patients with pituitary or parathyroid disease (27%). Furthermore, CgA levels of over 100 U/l occurred in 36/77 patients with GEP NETs (47%) and only in one patient with a non-functioning pituitary adenoma. In the patients with GEP NETs, both tumor burden and secretory activity affected CgA levels, and successful surgical resection was associated with markedly decreased CgA values.

CONCLUSIONS

Plasma CgA was confirmed to be a reliable marker for GEP NETs. Moreover, in MEN 1 patients the finding of very high CgA levels strongly suggests the presence of a GEP NET, as both primary hyperparathyroidism and pituitary adenomas rarely cause marked CgA increases.

To date, empirical literature has generally been considered lacking in relation to neuroendocrine carcinomas (NECs), the highly malignant subgroup of neuroendocrine neoplasms. NECs are often found in the lungs or the gastroenteropancreatic (GEP) system and can be of small or large cell type. Concentrating on GEP-NECs, we can conclude that survival times are poor, with a median of only 4-16 months depending on disease stage and primary site. Further, this aggressive disease appears to be on the rise, with incidence numbers increasing while survival times are stagnant. Treatment strategies concerning surgery are often undecided and second-line chemotherapy is not yet established. After an analysis of over 2600 articles, we can conclude that there is indeed more empirical literature concerning GEP-NECs available than previously assumed. This unique review is based on 333 selected articles and contains detailed information concerning all aspects of GEP-NECs. Namely, the classification, histology, genetic abnormalities, epidemiology, origin, biochemistry, imaging, treatment and survival of GEP-NECs are described. Also, organ-specific summaries with more detail in relation to disease presentation, diagnosis, treatment and survival are presented. Finally, key points are discussed with directions for future research priorities.