Gene expression profiling (GEP) is a well-established indispensable tool used to study hematologic malignancies, including leukemias. Here, we summarize the insights into the molecular basis of leukemias obtained by means of GEP, focusing especially on acute myeloid leukemia (AML), one of the first diseases to be extensively studied by GEP. Profiling mRNA and microRNA expression are discussed in view of their applicability to class prediction, class discovery, and comparison, as well as outcome prediction, and special attention is paid to the recent advances in our understanding of the role of alternative RNA splicing in AML. In addition to microarray-based GEP approaches, over the last few years RNA sequencing based on next-generation sequencing technology is gaining wider recognition as an advanced tool for transcriptome profiling. Therefore, the advantages of RNA sequencing-based GEP and its current and potential implications in AML are discussed. Finally, we also highlight recent efforts to integrate already available and newly acquired omics data sets so that a more precise understanding of AML biology and clinical behavior can be achieved, which ultimately will contribute to further refine leukemia management.

The Saccharomyces cerevisiae SSU1 gene was isolated based on its ability to complement a mutation causing sensitivity to sulfite, a methionine intermediate. SSU1 encodes a deduced protein of 458 amino acids containing 9 or 10 membrane-spanning domains but has no significant similarity to other proteins in public databases. An Ssu1p-GEP fusion protein was localized to the plasma membrane. Multicopy suppression analysis, undertaken to explore relationships among genes previously implicated in sulfite metabolism, suggests a regulatory pathway in which SSU1 acts downstream of FZF1 and SSU3, which in turn act downstream of GRR1.

This study compares the potencies of the porcine gastrin-releasing peptide (pGRP) and bombesin, in causing elevations of canine plasma gastroenteropancreatic (GEP) levels. In the dose range 0-600 pmol . kg-1 . h-1, infusion of both peptides resulted in obvious dose-related elevations of plasma levels of gastrin, pancreatic polypeptide, enteroglucagon, immunoreactive pancreatic glucagon, and insulin. In this dose range, no significant difference in potency between the two peptides in elevating plasma levels of the above hormones was observed. The results of this study, demonstrating equimolar potency of pGRP and bombesin, are in contrast to previous studies reporting that pGRP was less potent than bombesin in causing certain bioactivities in the rat following intracranial administration of the two peptides.

OBJECTIVE

Chronic Helicobacter pylori infection affects approximately half of the world, leads to chronic gastritis and peptic ulceration, and is linked to gastric carcinoma. Our aims were to compare the gene expression profile (GEP) of H. pylori-positive and H. pylori-negative gastric erosions and adjacent mucosa to explain the possible role and response to H. pylori infection and to get erosion-related mRNA expression patterns.

METHODS

Total RNA was extracted, amplified, and biotinylated from gastric biopsies of patients with H. pylori-positive and H. pylori-negative antrum erosions (ER) (8/8) and adjacent macroscopically normal mucosae (8/8). The GEP was evaluated using HGU133plus2.0 microarrays. Two independent normalizations (MAS5.0, RMA), PAM feature selection, hierarchical cluster analysis, and discriminant analysis were done. The expression of 14 genes was also measured by real-time-polymerase chain reaction. VCAM-1 and CXCL13 immunohistochemistry (IHC) was done.

RESULTS

In H. pylori infection, significant overexpression of MHC class II antigen-presenting genes, interleukin-7 receptor, ubiquitin-D, CXCR4, lactoferrin immune response-related genes, CXCL-2 and -13, CCL18 chemokine ligand, and VCAM-1 genes were established. In erosive gastritis, increased proliferation (MET) and transport (UCP2, SCFD1, KPNA4) were found, while genes associated with adhesion (SIGLEC11), transcription regulation (ESRRG), and electron and ion transport (ACADM, CLIC6) were down-regulated. Discriminant analysis successfully classified all samples into four groups (HP+ER-, HP+ER+, HP-ER+, HP-ER-) using a reduced gene set (20). Significant overexpression of VCAM-1 and CXC13 protein was detected by IHC in HP+ samples (p < .05).

CONCLUSIONS

Whole genomic microarray analysis yielded new H. pylori infection and erosion-related gene expression changes. Discriminative genes can be used in mRNA-based diagnostic classification of gastric biopsies.

Eighty-one primary ovarian carcinoids and intraovarian metastases from six mid-gut carcinoids were examined for the presence of tumor cells immunoreactive with antisera raised against various neurohormonal peptides, mostly of gastroenteropancreatic (GEP) origin. Twenty of the primary and two of the metastatic carcinoids contained such tumor cells. The incidence of tumors with any kind of neurohormonal peptide immunoreactive tumor cells was 53% in the trabecular carcinoids, and 42% in the strumal carcinoids, whereas the incidence was much lower (7%) in the insular type. Immunoreactive pancreatic polypeptide (PP), glucagon, enkephalin, and somatostatin were those neurohormonal peptides most commonly observed in the tumor cells of the primary carcinoids. Those less commonly found were substance P, calcitonin, VIP, neurotensin, beta-endorphin, and ACTH. Four metastatic carcinoids were nonreactive with all the antisera used. Cells storing immunoreactive insulin, glucagon, PP, VIP, gastrin, substance P, or enkephalin were found in one of the two remaining metastatic carcinoids; in the other only gastrin-immunoreactive tumor cells were observed. The occurrence and distribution of tumor cells storing the neurohormonal peptides in ovarian carcinoids are discussed in relation to their possible origin in the ovary and to carcinoids in the gut.

[(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is essential to optimize the initial staging and to predict the prognosis of diffuse large B-cell lymphoma (DLBCL). To assess the relationship between the germinal center B cell-like/activated B cell-like (GCB/ABC) classification and PET scan features in DLBCL, 57 cases treated with rituximab and a cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP)/CHOP-like regimen were analyzed. The expression profile of 18 GCB/ABC related genes and five genes coding for glucose transporters (GLUTs) was determined from frozen tissues using DASL (cDNA-mediated Annealing, Selection, Ligation and extension) technology. According to the gene expression profile (GEP), 30 cases of DLBCL were classified as GCB subtype (2-year progression-free survival [PFS] 76%) and 27 cases as ABC subtype (2-year PFS 51%, p = 0.03). Using a semiquantitative assessment of the decrease in standard uptake value (SUV) at interim PET performed after 3-4 cycles of chemotherapy, we defined fast (n = 36) and slow (n = 9) metabolic responders. In multivariate analysis, GCB/ABC subtype, age-adjusted international prognostic index (aaIPI) and slow/fast metabolic response were independent variables that predicted outcome. A score incorporating aaIPI, fast/slow metabolic response and GCB/ABC classification was used to define two groups with highly significantly distinct outcomes. Our study suggests that the combination of GEP, aaIPI and interim PET more accurately predicts DLBCL prognosis and is therefore suitable for tailoring therapeutic strategies.

The activated mutants of the α-subunits of G proteins G(12) and G(13) have been designated as the gep oncogenes owing to their ability to stimulate diverse oncogenic signaling pathways that lead to neoplastic transformation of fibroblast cell lines and tumorigenesis in nude mice models. Studies from our laboratory as well as others have shown that the growth-promoting activities of Gα(12) and Gα(13) involve potent activation of c-Jun N-terminal kinases (JNKs). Our previous studies have indicated that the JNK-interacting leucine zipper protein (JLP), a scaffold protein involved in the structural and functional organization of the JNK/p38 mitogen-activated protein kinase module, tethers Gα(12) and Gα(13) to the JNK signaling module. In the present study, in addition to demonstrating the physical association between JLP and Gα(12), we show that this interaction is enhanced by the receptor- or mutation-mediated activation of Gα(12). We also establish that JLP interacts with Gα(12) through the C-terminal domain that has been previously identified to be involved in binding to Gα(13). Furthermore, using this C-terminal domain as a competitively inhibitor of JLP that can disrupt Gα(12)-JLP interaction, we demonstrate that JLP is required for the stimulation of JNK by Gα(12). Our results also indicate that such JLP interaction is required for Gα(12) as well as Gα(13)-mediated neoplastic transformation of JLP. These studies demonstrate for the first time a functional role for JLP in the gep oncogene-regulated neoplastic signaling pathway.

Malignant transformation is caused by multi-step genetic mutations, and growth factors are believed to play important roles in developing and maintaining malignant phenotype. However, there is no direct evidence that a specific growth factor contributes to malignant transformation of phenotypically normal cells. In order to assess the function of Acrogranin (also known as granulin epithelial precursor; GEP) in ovarian carcinogenesis, ovarian surface epithelial (OSE) cells, which are supposed to be the origin of primary ovarian epithelial cancer, were transfected with combined genes of hTERT, SV40 LT, and Acrogranin. Introduction of hTERT and SV40 LT was sufficient for immortalizing OSE cells but not enough for tumor formation in nude mice. In contrast, transfection and overexpression of Acrogranin in immortalized OSE cells showed augmented clonogenicity in soft agar and obvious tumorigenicity in nude mice. This is the first study showing evidence that a specific growth factor plays a direct role in malignant transformation in ovarian cancer development.

BACKGROUND

Two types of intercellular junctions, synaptic junctions (SJs) and puncta adherentia junctions (PAs), are observed at the synapses between the mossy fibre terminals and the dendrites of pyramidal cells in the CA3 area of the hippocampus. SJs are associated with active zones and postsynaptic densities (PSDs) where neurotransmission occurs, whereas PAs are not associated with either of them. We have found that the nectin-afadin unit as well as the N-cadherin-catenin unit localizes at the PAs and that both the units cooperatively organize the PAs. Nectins are Ca2+-independent Ig-like cell-cell adhesion molecules and afadin is a nectin- and actin filament-binding protein that connects nectins to the actin cytoskeleton. Synaptic scaffolding molecule (S-SCAM) is a neural scaffolding protein which interacts with many proteins including neuroligin, NMDA receptors, neural plakophilin-related armadillo-repeat protein/delta-catenin, a GDP/GTP exchange protein for Rap1 small G protein (PDZ-Rap-GEP), and beta-catenin. S-SCAM has been suggested to be a component of PSDs, but its precise localization at the synapses remains unknown.

RESULTS

S-SCAM was not concentrated at the PSDs but highly concentrated and co-localized with nectins at both the sides of the PAs formed between the mossy fibre terminals and the dendrites of pyramidal cells in the CA3 area of the adult mouse hippocampus. S-SCAM co-localized with nectin-1 at the primitive synapses where the SJs and the PAs were not morphologically differentiated, and they co-localized during the maturation of the SJs and the PAs. Nectin-1 had a potency to recruit S-SCAM to the nectin-1-based cell-cell adhesion sites formed in cadherin-deficient L cells as a model system. This recruitment was dependent on the C-terminal PDZ domain-binding motif of nectin-1 which is necessary for the binding of afadin, suggesting that nectins recruit S-SCAM through afadin. Consistently, S-SCAM was co-immunoprecipitated with afadin by the anti-S-SCAM antibody from the mouse brain, but S-SCAM did not directly bind afadin.

CONCLUSIONS

These results indicate that S-SCAM localizes at the PAs in the CA3 area of the hippocampus in a nectin-dependent manner and suggest that S-SCAM serves as a scaffolding molecule at the PAs after maturation of the synapses and at the SJs during the maturation.

A large number of antisera mainly raised against mammalian hormones are tested immunocytochemically on the GEP-endocrine system of mouse and fish (Barbus conchonius). The endocrine pancreas of mouse and fish appeared to contain the same four endocrine cell types; insulin-, glucagon-, PP- and somatostatin-immunoreactive cells. In mouse about 13 GEP endocrine cell types are distinguished: 1. insulin-, 2. somatostatin-, 3. glucagon-, 4. PP-, 5. (entero)glucagon-/PP-like, 6. CCK-like, 7. substance P-, 8. neurotensin-, 9. VIP-, 10. gastrin-, 11. secretin-, 12. beta-endorphin-, 13. serotonin-immunoreactive cells. Based on this and a previous study at least 13 GEP endocrine cell types seems to be present in stomachless fish: 1-9 as described for mouse, 10. (entero)glucagon-like, 11. met-enkephalin, 12. VIP-like, 13. unspecific immunoreactive endocrine cells. Coexistence of glucagon and PP-like peptides is found in the gut and pancreas of mice and in the gut of B. conchonius. In mouse pancreas and fish gut, endocrine cells showing only PP- or glucagon-like immunoreactivity are found too. In mouse stomach some endocrine cells showing only PP-immunoreactivity are demonstrated. In the same region coexistence of C-t-gastrin- and FMRF-amide-immunoreactivity is found in endocrine cells. The importance of these phenomena are discussed. Enteric nerves immunoreactive with antisera raised against substance P and GRP are found in mouse, against somatostatin and met-enkephalin in both mouse and fish and against VIP in fish.

While somatostatin receptors (sst), through somatostatin-radiolabeled analogs, are used, mainly in second line, in the diagnosis and treatment of pheochromocytomas (PCC) and paragangliomas (PGL), the clinical significance of dopamine receptor subtype 2 (D₂) in PCC/PGL is unknown. Indeed, radiolabeled dopamine (DA) analogs such as fluorine 18 ((18)F)-DA, used for positron emission tomography in PCC localization, are mainly correlated to the presence of noradrenaline transporter (NAT) and vesicular monoamine transporters (VMAT) but not to D₂. The aim of this study was to quantitate D₂ and sst expression in 52 PCC/PGL and to compare it with that of 35 gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Quantitative RT-PCR of sst(1-3) and sst₅, D₂, NAT, VMAT1/2 was performed in all tumors, while immunohistochemistry analysis of sst₂ and D₂ was performed in seven tumors. D₂ mRNA was expressed in all PCC/PGL. Mean expression was significantly higher in PCC/PGL than in GEP-NETs (4.8 vs 0.5 copy/copy β-glucuronidase (Gus)). sst₂ and sst(1) were expressed in most PCC/PGL, with sst(2)-dominant expression (mean mRNA: 1.6 vs 0.4 copy/copy β-Gus). sst₂ expression level was similar to that of GEP-NETs, whereas sst₅ expression level was significantly lower (0.12 vs 0.78 copy/copy β-Gus). Our study evidenced strong D₂ mRNA expression in PCC and for the first time in PGL. PCC/PGL express sst₂ mRNA at levels similar to those of GEP-NETs. New drugs can target ssts and D₂ more efficiently than current somatostatin analogs. Moreover, transporters like NAT and VMAT1/2, could be co-targeted with sst, as a basis of new radionuclide compounds in the imaging and treatment of these tumors.

The results of both phylogenetic and ontogenetic investigations of the evolution of the disseminated NE cells of the GIT have shown that they are members of the large NE system, consisting not only of the GI-NE cells but also of the neurons of the central and peripheral nervous system with their nerve fibers (the peptidergic nervous system) and of the classic, solid endocrine glands. The evolutionary studies also have shown that these three major parts of the NE system are closely interrelated to each other. The most original part is obviously the neuronal one, occurring already in the most primitive animals (the coelenterates). The next step in the evolution of the NE system is the appearance of NE cells of open type in the mucosa of the alimentary tract. Such gut NE cells are present in the most highly developed invertebrates, both Protostomian and Deuterostomian, and they persist and become even more diversified in the vertebrates, including humans. The presence of GEP-NE glands of classic, solid type seems to be a feature restricted to the true vertebrate animals. The earliest vertebrates (the jawless fish and the cartilaginous fish) often offer the best pieces of evidence for the manner in which the parenchyma of such a GEP-NE gland, notably the islets of Langerhans, is formed from disseminated NE cells of open type in a mucosa, in this case that of the gut.

A Native American-Indian female presenting with anemia and thrombocytosis was diagnosed with myelodysplastic syndrome (MDS, refractory anemia). Over the course of 5 years she developed cytopenias and periods of leukocytosis with normal bone marrow (BM) blast counts, features of an unclassifiable MDS/MPS syndrome. The patient ultimately progressed to acute myelogenous leukemia (AML, FAB M2) and had a normal karyotype throughout her course. The episodes of leukocytosis were associated with infectious complications. Transformation to AML was characterized by a BM blast percentage of 49%. Peripheral blood and BM samples were obtained for serum protein analysis and gene expression profiling (GEP) to elucidate her disease process. An ELISA assay of the serum analyzed approximately 80 cytokines, which demonstrated that hepatocyte growth factor/scatter factor and insulin-like growth factor binding protein 1 were markedly elevated compared to normal. GEP demonstrated a unique "tumor molecular profile," which included overexpression of oncogenes (HOXA9, N-MYC, KOC1), proliferative genes (PAWR, DLG5, AKR1C3), invasion/metastatic genes (FN1, N-CAM-1, ITGB5), pro-angiogenesis genes (c-Kit), and down regulation of tumor suppressor genes (SUI1, BARD1) and anti-apoptotic genes (PGLYRP, SERPINB2, MPO). Hence, a biomics approach has provided insight into elucidating disease mechanisms, molecular prognostic factors, and discovery of novel targets for therapeutic intervention.

Endocrine pancreatic tumors (EPTs) are a heterogeneous group of neoplasms with variable clinical and biological features and prognosis, ranging from very slow-growing tumors to highly aggressive and very malignant ones. As other neuroendocrine tumors, EPTs are characterized by the presence of neuroamine uptake mechanisms and/or peptide receptors at the cell membrane and these features constitute the basis of the clinical use of specific radiolabeled ligands, both for imaging and therapy. The more widespread use of hybrid machines, i.e., positron emission tomography/computed tomography (PET/CT), allows to perform imaging with high resolution and high diagnostic accuracy especially for small lesions, and to correlate anatomic location with function. The recent WHO recommendations for classification and prognostic factors help the selection of tracers likely to show a positive image on PET; therefore, tracers exploiting specific metabolic patterns ((18)F-DOPA and (11)C-5-HTP) or specific receptor expression ((68)Ga-DOTA-peptides) are suited to well-differentiated tumors, while the use of (18)F-FDG is preferred for poorly-differentiated neoplasms with high proliferative activity and loss of neuroendocrine features. In differentiated EPTs, (11)C-5-HTP performs better than (18)F-DOPA even though its use is hampered by its complex production and limited availability and experience; (68)Ga-peptides are indicated for all type of gastroenteropancreatic (GEP) neuroendocrine tumors, regardless of their functional activity. In addition, (68)Ga-DOTA-peptides play a distinctive role in planning peptide receptor radionuclide therapy.

We report on prognostic implications for post-relapse survival (PRS) of a gene expression profiling (GEP)-defined risk score at relapse available in 120 myeloma patients previously enrolled in tandem transplantation trial Total Therapy 2. Among the 71 patients with additional GEP baseline information, 3-year PRS was 71% in 40 patients with low risk present both at baseline and relapse contrasting with only 17% in 28 patients with high risk at relapse, 12 of whom with baseline low-risk status fared better than the remainder (P = .08). On multivariate analysis of relapse parameters available in 104 patients, high risk conferred short PRS (hazard ratio = 4.00, P < .001, R(2) = 33%), whereas relapse hyperdiploidy predicted long PRS (hazard ratio = 0.37, P = .022, cumulative R(2) = 41%). In case the initial partial response lasted less than 2 years, relapse low-risk identified 26 patients with superior 3-year PRS of 61% versus 9% among 32 with relapse high-risk (P < .001). Based on its PRS predictive power, GEP analysis should be an integral part of new agent trials in search of better therapy for high-risk myeloma.

During the early 1980s liver transplantation (LTx) was expected to be a promising therapeutic option for patients with primary or secondary tumors confined to the liver. Because of disappointing results owing to death from early recurrence, LTx is currently restricted to well selected patients with small primary tumors and, in the case of liver metastases, to those with metastases of gastroenteropancreatic (GEP) tumor origin only. In our series of 300 liver transplantations four patients with GEP tumor metastases underwent LTx. The primary tumors were one neuroendocrine kidney tumor, one glucagonoma of the pancreas, and two cases of carcinoids of the pancreas. Because of local metastatic lymph node involvement upper gastrointestinal exenteration followed by LTx was performed in two patients. No patient survived beyond 33 months after LTx. Three patients died from tumor recurrence. In one patient who died from fungal sepsis autopsy revealed spine metastases that had been missed before LTx. Our dismal results do not compare well with promising data published previously by others for this particular patient group. Under the pressure of an increasing donor organ shortage, patients with GEP tumor metastases should be selected carefully for LTx.

BACKGROUND

Recent reports indicate that in vitro drug screens combined with gene expression profiles (GEP) of cancer cell lines may generate informative signatures predicting the clinical outcome of chemotherapy. In multiple myeloma (MM) a range of new drugs have been introduced and now challenge conventional therapy including high dose melphalan. Consequently, the generation of predictive signatures for response to melphalan may have a clinical impact. The hypothesis is that melphalan screens and GEPs of B-cell cancer cell lines combined with multivariate statistics may provide predictive clinical information.

METHODS

Microarray based GEPs and a melphalan growth inhibition screen of 59 cancer cell lines were downloaded from the National Cancer Institute database. Equivalent data were generated for 18 B-cell cancer cell lines. Linear discriminant analyses (LDA), sparse partial least squares (SPLS) and pairwise comparisons of cell line data were used to build resistance signatures from both cell line panels. A melphalan resistance index was defined and estimated for each MM patient in a publicly available clinical data set and evaluated retrospectively by Cox proportional hazards and Kaplan-Meier survival analysis.

RESULTS

Both cell line panels performed well with respect to internal validation of the SPLS approach but only the B-cell panel was able to predict a significantly higher risk of relapse and death with increasing resistance index in the clinical data sets. The most sensitive and resistant cell lines, MOLP-2 and RPMI-8226 LR5, respectively, had high leverage, which suggests their differentially expressed genes to possess important predictive value.

CONCLUSIONS

The present study presents a melphalan resistance index generated by analysis of a B-cell panel of cancer cell lines. However, the resistance index needs to be functionally validated and correlated to known MM biomarkers in independent data sets in order to better understand the mechanism underlying the preparedness to melphalan resistance.

OBJECTIVE

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) expressing somatostatin receptors may be treated with somatostatin analogs (SSAs). Selection criteria are a positive Octreoscan or a >50% hormone level decrease after octreotide subcutaneous (s.c.) injection (octreotide test) (OT). Plasma chromogranin A (CgA) is the best general GEP-NET marker, but data on CgA response to OT are scanty. Thus, we evaluated whether plasma CgA response to OT could predict the clinical response to SSAs.

METHODS

At diagnosis, 38 GEP-NET patients received octreotide 200 microg s.c., with plasma CgA determination at 0, 3, and 6 h. Long-term SSA treatment was then given by monitoring symptomatic, biochemical, and objective responses, and survival.

RESULTS

Basal plasma CgA levels were significantly higher in patients with functioning than non-functioning tumors (median (range): 220 (18-2,230) vs. 46 (25-8,610) U/l, P=0.03) and in those with than without metastases (171 (18-8,610) vs. 43 (28-220) U/l, P=0.04). CgA levels significantly correlated with WHO classification, clinical TNM staging, and Ki-67 proliferative index. After OT, CgA levels decreased from 146 (18-8,610) to 61 (10-8,535) U/l (basal and nadir values), P<0.001. In patients responsive to OT, a successful objective response occurred in 21/31 patients (68%). Successful symptomatic response occurred in 13/18 patients (72%), biochemical response in 25/31 (81%), and objective response in 21/31 (68%). In the remaining seven unresponsive cases, with CgA decrement <30%, disease progressed to death in six (86%). Median survival from enrollment was 48 months (6-138) in responsive and 6 (6-30) in unresponsive patients (P=0.0005).

CONCLUSIONS

In GEP-NETs, plasma CgA is a reliable marker, and a >30% decrease after OT has a relevant prognostic meaning allowing the identification of the subgroup of patients most likely to be responsive to chronic SSAs.

Retroviral insertion mutagenesis is considered a powerful tool to identify cancer genes in mice, but its significance for human cancer has remained elusive. Moreover, it has recently been debated whether common virus integrations are always a hallmark of tumor cells and contribute to the oncogenic process. Acute myeloid leukemia (AML) is a heterogeneous disease with a variable response to treatment. Recurrent cytogenetic defects and acquired mutations in regulatory genes are associated with AML subtypes and prognosis. Recently, gene expression profiling (GEP) has been applied to further risk stratify AML. Here, we show that mouse leukemia genes identified by retroviral insertion mutagenesis are more frequently differentially expressed in distinct subclasses of adult and pediatric AML than randomly selected genes or genes located more distantly from a virus integration site. The candidate proto-oncogenes showing discriminative expression in primary AML could be placed in regulatory networks mainly involved in signal transduction and transcriptional control. Our data support the validity of retroviral insertion mutagenesis in mice for human disease and indicate that combining these murine screens for potential proto-oncogenes with GEP in human AML may help to identify critical disease genes and novel pathogenetic networks in leukemia.

Introduction. The role of hepatic resection in patients with liver metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs) is still poorly defined. Therefore, we examined the results obtained with surgical resection and other locoregional or systemic therapies by reviewing the recent literature on this topic. We performed the meta-analysis for comparing surgical resection of hepatic metastases with other treatments. Materials and Methods. In this systematic review and meta-analysis of observational studies, the literature search was undertaken between 1990 and 2012 looking for studies evaluating the different survivals between patients treated with surgical resection of hepatic metastases and with other surgical or nonsurgical therapies. The studies were evaluated for quality, publication bias, and heterogeneity. Pooled hazard ratio (HR) estimates and 95% confidence intervals (CI.95) were calculated using fixed-effects model. Results. We selected six studies in the review, five of which were suitable for meta-analysis. We found a significant longer survival in patients treated with hepatic resection than embolisation HR 0.34 (CI.95 0.21-0.55) or all other nonsurgical treatments HR 0.45 (CI.95 0.34-0.60). Only one study compared surgical resection with liver transplantation and meta-analysis was not feasible. Conclusions. Our meta-analysis provides evidence supporting the hypothesis that hepatic resection increases overall survival in patients with liver metastases from GEP-NETs. Further randomized clinical trials are needed to confirm these findings and it would be desirable to identify new markers to properly select patients for surgical treatment.

BACKGROUND

To date, more than 60 gene expression profiling (GEP) studies have been published in the field of head and neck squamous cell carcinoma (HNSCC) with variable objectives, methods, and results.

METHODS

The purpose of this study was to present a state-of-the-art review of GEP in HNSCC focusing on the current advances and perspectives for clinical applications.

RESULTS

Gene expression signatures have been developed to identify screening and diagnostic molecular markers, to improve tumor staging (cervical lymph node and distant metastasis prediction), to differentiate lung metastasis of HNSCC from primary lung squamous cell carcinoma, to predict tumor response to chemoradiotherapy, and to provide outcome predictors.

CONCLUSIONS

Some transcriptional signatures that could improve HNSCC management have been identified, but further analyses are required to properly validate and to precisely evaluate their clinical relevance. After an exploratory phase, the completion of large scale projects with stringent methodology is now necessary to transfer GEP from bench to bedside.

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) is an effective method for treating neuroendocrine tumors (NETs). It is limited, however, in the prediction of individual tumor response and the precise and early identification of changes in tumor size. Currently, response prediction is based on somatostatin receptor expression and efficacy by morphological imaging and/or chromogranin A (CgA) measurement. The aim of this study was to assess the accuracy of circulating NET transcripts as a measure of PRRT efficacy, and moreover to identify prognostic gene clusters in pretreatment blood that could be interpolated with relevant clinical features in order to define a biological index for the tumor and a predictive quotient for PRRT efficacy.

METHODS

NET patients (n = 54), M: F 37:17, median age 66, bronchial: n = 13, GEP-NET: n = 35, CUP: n = 6 were treated with (177)Lu-based-PRRT (cumulative activity: 6.5-27.8 GBq, median 18.5). At baseline: 47/54 low-grade (G1/G2; bronchial typical/atypical), 31/49 (18)FDG positive and 39/54 progressive. Disease status was assessed by RECIST1.1. Transcripts were measured by real-time quantitative reverse transcription PCR (qRT-PCR) and multianalyte algorithmic analysis (NETest); CgA by enzyme-linked immunosorbent assay (ELISA). Gene cluster (GC) derivations: regulatory network, protein:protein interactome analyses.

METHODS

chi-square, non-parametric measurements, multiple regression, receiver operating characteristic and Kaplan-Meier survival.

RESULTS

The disease control rate was 72 %. Median PFS was not achieved (follow-up: 1-33 months, median: 16). Only grading was associated with response (p < 0.01). At baseline, 94 % of patients were NETest-positive, while CgA was elevated in 59 %. NETest accurately (89 %, χ(2) = 27.4; p = 1.2 × 10(-7)) correlated with treatment response, while CgA was 24 % accurate. Gene cluster expression (growth-factor signalome and metabolome) had an AUC of 0.74 ± 0.08 (z-statistic = 2.92, p < 0.004) for predicting response (76 % accuracy). Combination with grading reached an AUC: 0.90 ± 0.07, irrespective of tumor origin. Circulating transcripts correlated accurately (94 %) with PRRT responders (SD+PR+CR; 97 %) vs. non-responders (91 %).

CONCLUSIONS

Blood NET transcript levels and the predictive quotient (circulating gene clusters+grading) accurately predicted PRRT efficacy. CgA was non-informative.

Substantial additional insight has been obtained in the past decade regarding the pathogenesis of diffuse large B cell lymphoma (DLBCL). Distinct subtypes of DLBCL have been defined by gene expression profiling (GEP) and they differ not only in GE profiles but also in the pattern of genetic abnormalities. The ability to correlate corresponding genetic and GEP data markedly facilitates the identification of target genes in regions with copy number abnormalities. Oncogenic pathways are often differentially activated in these different subtypes of DLBCL, suggesting that therapy should be targeted according to these differences. The tumor microenvironment plays a significant role in determining outcome and may be a novel target for therapy. The role of microRNA in lymphomagenesis is increasingly being recognized and mutation of key genes has been demonstrated to drive the activation of the NF-kappaB pathway and B cell receptor signaling. The pace of discovery will be even more rapid in the near future with the convergence of data from multiple complementary genome-wide studies and technological innovations including the rapid advance in the technology of high-throughput sequencing.

OBJECTIVE

To evaluate the significance of plasma chromogranin A (CgA) levels in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET) in terms of disease status and treatment responses.

METHODS

Forty-four GEP-NET patients comprising 15 disease-free patients and 29 patients with active disease, as well as 26 healthy participants were enrolled in this study between April 2010 and April 2011. Clinicopathological factors were collected and serial plasma CgA levels were measured.

RESULTS

Plasma CgA levels were significantly higher in GEP-NET patients with active disease than in disease-free patients (p = 0.011) or healthy participants (p = 0.001). No difference in CgA levels was observed in terms of primary tumor location, tumor grade, and functional status in patients with active disease. CgA values at 94 U/l distinguished healthy individuals or disease-free patients from patients with active disease. Sensitivity and specificity rates were 86 and 88%, respectively. CgA levels at 110 U/l differentiated patients without recurrence from those with recurrence, with a sensitivity rate of 100% and a specificity rate of 80%. Patients (5/5, 100%) with stable disease and who showed partial response after treatment had a more than 20% decrease in CgA levels compared with the baseline values. Patients (6/6, 100%) with progressive disease showed a less than 20% decrease or increase in CgA levels.

CONCLUSIONS

The plasma CgA level is a reliable biomarker for GEP-NET. We conclude that changes in CgA levels are associated with disease status and treatment responses.