Highly Selective Nickel-Catalyzed Isomerization-Hydroboration of Alkenes Affords Terminal Functionalization at Remote C-H Position.

We report herein the synthesis and characterization of nickel complexes supported by tridentate and bidentate phosphino(silyl) ancillary ligands, along with the successful application of these complexes as precatalysts for the hydroboration of terminal and internal alkenes using pinacolborane (HBPin). These reactions proceeded with low nickel loadings of 2.5-5 mol % in the absence of co-solvent, and in some cases at room temperature. Isomerization to afford exclusively the terminal hydroboration product was obtained across a range of internal alkenes, including tri- and tetra-substituted examples. This reactivity is unprecedented for nickel and offers a powerful means of achieving functionalization at a C-H position remote from the C=C double bond. Nickel-catalyzed deuteroboration experiments using DBPin support a mechanism involving 1,2-insertion of the alkene and subsequent chain-walking, which results in isotopic scrambling.

Predictive blood biomarkers and brain changes associated with age-related cognitive decline.

Growing evidence supports the use of plasma levels of tau phosphorylated at threonine 181, amyloid-ß, neurofilament light and glial fibrillary acidic protein as promising biomarkers for Alzheimer's disease. While these blood biomarkers are promising for distinguishing people with Alzheimer's disease from healthy controls, their predictive validity for age-related cognitive decline without dementia remains unclear. Further, while tau phosphorylated at threonine 181 is a promising biomarker, the distribution of this phospho-epitope of tau in the brain is unknown. Here, we tested whether plasma levels of tau phosphorylated at threonine 181, amyloid-ß, neurofilament light and fibrillary acidic protein predict cognitive decline between ages 72 and 82 in 195 participants in the Lothian birth cohorts 1936 study of cognitive ageing. We further examined post-mortem brain samples from temporal cortex to determine the distribution of tau phosphorylated at threonine 181 in the brain. Several forms of tau phosphorylated at threonine 181 have been shown to contribute to synapse degeneration in Alzheimer's disease, which correlates closely with cognitive decline in this form of dementia, but to date, there have not been investigations of whether tau phosphorylated at threonine 181 is found in synapses in Alzheimer's disease or healthy ageing brain. It was also previously unclear whether tau phosphorylated at threonine 181 accumulated in dystrophic neurites around plaques, which could contribute to tau leakage to the periphery due to impaired membrane integrity in dystrophies. Brain homogenate and biochemically enriched synaptic fractions were examined with western blot to examine tau phosphorylated at threonine 181 levels between groups (n = 10-12 per group), and synaptic and astrocytic localization of tau phosphorylated at threonine 181 were examined using array tomography (n = 6-15 per group), and localization of tau phosphorylated at threonine 181 in plaque-associated dystrophic neurites with associated gliosis were examined with standard immunofluorescence (n = 8-9 per group). Elevated baseline plasma tau phosphorylated at threonine 181, neurofilament light and fibrillary acidic protein predicted steeper general cognitive decline during ageing. Further, increasing tau phosphorylated at threonine 181 over time predicted general cognitive decline in females only. Change in plasma tau phosphorylated at threonine 181 remained a significant predictor of g factor decline when taking into account Alzheimer's disease polygenic risk score, indicating that the increase of blood tau phosphorylated at threonine 181 in this cohort was not only due to incipient Alzheimer's disease. Tau phosphorylated at threonine 181 was observed in synapses and astrocytes in both healthy ageing and Alzheimer's disease brain. We observed that a significantly higher proportion of synapses contain tau phosphorylated at threonine 181 in Alzheimer's disease relative to aged controls. Aged controls with pre-morbid lifetime cognitive resilience had significantly more tau phosphorylated at threonine 181 in fibrillary acidic protein-positive astrocytes than those with pre-morbid lifetime cognitive decline. Further, tau phosphorylated at threonine 181 was found in dystrophic neurites around plaques and in some neurofibrillary tangles. The presence of tau phosphorylated at threonine 181 in plaque-associated dystrophies may be a source of leakage of tau out of neurons that eventually enters the blood. Together, these data indicate that plasma tau phosphorylated at threonine 181, neurofilament light and fibrillary acidic protein may be useful biomarkers of age-related cognitive decline, and that efficient clearance of tau phosphorylated at threonine 181 by astrocytes may promote cognitive resilience.

Neurogranin in Alzheimer's disease and ageing: A human post-mortem study.

Neurogranin (Ng), a post-synaptic protein involved in memory formation, has been investigated as a biomarker in the cerebrospinal fluid (CSF) in Alzheimer's disease (AD) and ageing. CSF Ng levels are elevated in AD relative to healthy controls and correlate with cognition; however, few studies have focused on Ng abundance in the brain. Synapse loss in the brain correlates closely with cognitive decline in AD making synaptic biomarkers potentially important for tracking disease progression, but the links between synaptic protein changes in CSF and brain remain incompletely understood. In the current study, Ng abundance was examined in post-mortem human brain tissue across AD, healthy ageing (HA), and mid-life (ML) cohorts. Ng levels were quantified in three brain regions associated with cognitive change found during ageing and neurodegenerative diseases, namely the middle temporal gyrus, primary visual cortex and the posterior hippocampus using immunohistochemistry. To support immunohistochemical analysis, total homogenate and biochemically enriched synaptic fractions from available temporal gyrus tissues were examined by immunoblot. Finally, we examined whether Ng is associated with lifetime cognitive ageing. Ng levels were significantly reduced in AD relative to HA and ML cases across all regions. Additionally Ng was significantly reduced in HA in comparison to ML in the primary visual cortex. Immunoblotting confirms reduced Ng levels in AD cases supporting immunohistochemical results. Interestingly, there was also a significant reduction of synapse-associated Ng in our group who had lifetime cognitive decline in comparison to the group with lifetime cognitive resilience indicating loss of neurogranin in remaining synapses during ageing is associated with cognitive decline. Our findings indicate that increases in CSF Ng reflect loss of brain neurogranin and support the use of CSF Ng as a biomarker of AD and potentially of cognitive decline in healthy ageing.

Is quality of life related to high autistic traits, high ADHD traits and their Interaction? Evidence from a Young-Adult Community-Based twin sample.

This study explored whether high autistic traits, high attention deficit hyperactivity disorder (ADHD) traits and their interaction were associated with quality of life (QoL) in a sample of 556 of young-adult twins (Mean age 22 years 5 months, 52% Female). Four participant groups were created: high autistic traits, high ADHD traits, high autistic/ADHD traits, and low ADHD/autistic traits. High autistic traits were associated with lower QoL across domains (physical, psychological, social, and environmental). High ADHD traits associated with lower physical, psychological, and environmental QoL. The interaction of autistic and ADHD traits was not significant in any domain. While mental health difficulties were associated with lower QoL, after accounting for mental health, most relationships between autistic traits, ADHD traits and QoL remained.

Interactions between apolipoprotein E, sex, and amyloid-beta on cerebrospinal fluid p-tau levels in the European prevention of Alzheimer's dementia longitudinal cohort study (EPAD LCS).

BACKGROUND: Alzheimer's Disease, the leading cause of dementia, is over-represented in females. The apolipoprotein E (APOE)ε4 allele is the strongest genetic risk factor for late-onset AD and is associated with aberrant cerebrospinal fluid levels (CSF) of total tau (t-tau), phosphorylated tau (p-tau), and amyloid-ß (Aß). There is some evidence that sex may mediate the relationship between APOE status and CSF tau, however, evidence is mixed. METHODS: We aimed to examine the interaction between sex, APOE ε4 status, CSF Aß on t-tau and p-tau in 1599 mid-to-late life individuals without a diagnosis of dementia in the European Prevention of Alzheimer's Dementia (EPAD) longitudinal cohort study. FINDINGS: We found a significant interaction between APOE status, sex, and CSF Aß on CSF p-tau levels (ß = 0·18, p = 0·04). Specifically, there was a stronger association between APOE status and CSF Aß42 on CSF p-tau in males compared to females. Further, in females with high Aß levels (reflecting less cortical deposition), ε4 carriers had significantly elevated p-tau levels relative to non-carriers (W = 39663, p = 0·01). However, there were no significant differences in p-tau between male ε4 carriers and non-carriers with high Aß (W = 23523, p = 0·64). INTERPRETATION: An interaction between sex and cerebrospinal fluid Aß may mediate the relationship between APOE status and CSF p-tau. These data suggest tau accumulation may be independent of Aß in females, but not males. FUNDING: Innovative Medicines Initiative, Swedish Research Council, Alzheimer Drug Discovery Foundation, Swedish Alzheimer Foundation, the Swedish state under the agreement between the Swedish government and the County Councils: the ALF-agreement, and the Alzheimer's Association 2021 Zenith Award.

Associations between cerebrospinal fluid markers and cognition in ageing and dementia: A systematic review.

A biomarker associated with cognition in neurodegenerative dementias would aid in the early detection of disease progression, complement clinical staging and act as a surrogate endpoint in clinical trials. The current systematic review evaluates the association between cerebrospinal fluid protein markers of synapse loss and neuronal injury and cognition. We performed a systematic search which revealed 67 studies reporting an association between cerebrospinal fluid markers of interest and neuropsychological performance. Despite the substantial heterogeneity between studies, we found some evidence for an association between neurofilament-light and worse cognition in Alzheimer's diseases, frontotemporal dementia and typical cognitive ageing. Moreover, there was an association between cerebrospinal fluid neurogranin and cognition in those with an Alzheimer's-like cerebrospinal fluid biomarker profile. Some evidence was found for cerebrospinal fluid neuronal pentraxin-2 as a correlate of cognition across dementia syndromes. Due to the substantial heterogeneity of the field, no firm conclusions can be drawn from this review. Future research should focus on improving standardization and reporting as well as establishing the importance of novel markers such as neuronal pentraxin-2 and whether such markers can predict longitudinal cognitive decline.

Surgical Resection of 78 Pancreatic Solid Pseudopapillary Tumors: a 30-Year Single Institutional Experience.

BACKGROUND: Solid pseudopapillary tumors (SPTs) are rare, benign tumors of the pancreas that present as heterogeneous masses. We sought to evaluate the short- and long-term outcomes of surgical resected SPTs. Patients managed via initial surveillance were compared to those who underwent upfront resection. METHODS: A prospectively maintained institutional database was used to identify patients who underwent surgical resection for a SPT between 1988 and 2018. Data on clinicopathological features and outcomes were collected and analyzed. RESULTS: Seventy-eight patients underwent surgical resection for SPT during the study period. The mean age was 34.0 ± 14.6 years and a majority were female (N = 67, 85.9%) and white (N = 46, 58.9%). Thirty patients (37.9%) were diagnosed incidentally. Imaging-based presumed diagnosis was SPT in 49 patients (62.8%). A majority were located in the body or tail of the pancreas (N = 47, 60.3%), and 48 patients (61.5%) underwent a distal pancreatectomy. The median tumor size was 4.0 cm (IQR, 3.0-6.0), nodal disease was present in three patients (3.9%), and R0 resection was performed in all patients. No difference was observed in clinicopathological features and outcomes between patients who were initially managed via surveillance and those who underwent upfront resection. None of the patients under surveillance had nodal disease or metastasis at the time of resection; however, one of them developed recurrence of disease 95.1 months after resection. At a median follow-up of 36.1 months (IQR, 8.1-62.1), 77 (%) patients were alive and one patient (1.3%) had a recurrence of disease at 95.1 months after resection and subsequently died due to disease. CONCLUSIONS: SPTs are rare pancreatic tumors that are diagnosed most frequently in young females. While a majority are benign and have an indolent course, malignant behavior has been observed. Surgical resection can result in exceptional outcomes.

Pituitary volume in individuals at elevated risk for psychosis: A systematic review and meta-analysis.

BACKGROUND: Pituitary volume (PV) abnormalities, representing one of several markers of hypothalamic-pituitary-adrenal (HPA) axis dysregulation, have been observed in psychosis, with variable patterns across illness stages. Typically, enlargements characterise first-episode patients, with reductions observed in those with chronic illness relative to healthy controls. Findings in high-risk populations have been inconsistent, highlighting the need for an updated review of the evidence. METHODS: We searched PubMed, PsycINFO, and EMBASE for studies examining PV in high-risk [clinical high-risk (CHR), family history of psychosis (FHx), schizotypal personality disorder (SPD), and psychotic-experiences (PEs)] and healthy individuals. Random effects models were used to examine group differences in PV (Hedges g) with stratified analyses and meta-regression employed to investigate the effect of high-risk category, transition status, age, sex, and antipsychotic medication. RESULTS: Ten studies, yielding 11 effect sizes, were eligible for inclusion. Overall, high-risk individuals had significantly larger PV relative to healthy controls (g = 0.16 [95% CI: 0.01 to 0.32] p = 0.04), despite showing a reduction in whole brain volume (g = -0.17, [95% CI. -0.30 to -0.03] p = 0.020). Individual sub-group analyses for CHR and FHx groups showed no significant differences relative to controls; however, larger PV increases characterised those who later transitioned to psychosis (g = 0.55, [95% CI. 0.06 to 1.04] p = 0.028). Larger effect sizes were positively associated with the proportion of high-risk individuals receiving antipsychotic medication. CONCLUSIONS: PV enlargements characterise high-risk individuals and are more pronounced among those who later develop psychosis. We provide recommendations for future studies.

Epigenomic reprogramming during pancreatic cancer progression links anabolic glucose metabolism to distant metastasis.

During the progression of pancreatic ductal adenocarcinoma (PDAC), heterogeneous subclonal populations emerge that drive primary tumor growth, regional spread, distant metastasis, and patient death. However, the genetics of metastases largely reflects that of the primary tumor in untreated patients, and PDAC driver mutations are shared by all subclones. This raises the possibility that an epigenetic process might operate during metastasis. Here we report large-scale reprogramming of chromatin modifications during the natural evolution of distant metastasis. Changes were targeted to thousands of large chromatin domains across the genome that collectively specified malignant traits, including euchromatin and large organized chromatin histone H3 lysine 9 (H3K9)-modified (LOCK) heterochromatin. Remarkably, distant metastases co-evolved a dependence on the oxidative branch of the pentose phosphate pathway (oxPPP), and oxPPP inhibition selectively reversed reprogrammed chromatin, malignant gene expression programs, and tumorigenesis. These findings suggest a model whereby linked metabolic-epigenetic programs are selected for enhanced tumorigenic fitness during the evolution of distant metastasis.

Mutant p53 Together with TGFß Signaling Influence Organ-Specific Hematogenous Colonization Patterns of Pancreatic Cancer.

Purpose: TP53 and the TGFß pathway are major mediators of pancreatic cancer metastasis. The mechanisms by which they cause hematogenous metastasis have not been fully explored.Experimental Design:KPC (LSL-KRASG12D/+;LSL-Trp53R172H/+; Ptf1aCre/+) mice were generated, and the frequency and morphology of organ-specific hematogenous metastases compared with that seen in KPTC and KTC littermates (Tgfbr2+/-). Key findings were validated in primary cells from each genotype and samples of human pancreatic cancer liver metastases.Results: The frequency of hematogenous metastasis in KPTC mice was significantly lower than for KPC mice (41% vs. 68%, P < 0.05), largely due to a reduction in liver metastases. No differences were found between KPC and KPTC lung metastases, whereas liver metastases in KPTC mice showed a profound extravasation deficiency characterized by sinusoidal growth and lack of desmoplastic stroma. Analogous findings were confirmed in liver samples from patients indicating their clinical relevance. Portal vein colonization as a direct mode of access to the liver was observed in both mice and humans. Secretome analyses of KPC cells revealed an abundance of secreted prometastatic mediators including Col6A1 and Lcn2 that promoted early steps of metastatic colonization. These mediators were overexpressed in primary tumors but not metastases, suggesting that the ability to colonize is, in part, developed within the primary site, a phenomenon we refer to as the "Cinderella effect."Conclusions: These findings establish a novel paradigm for understanding pancreatic cancer metastasis and the observed clinical latencies of liver versus lung metastases specifically. Clin Cancer Res; 23(6); 1607-20. ©2016 AACR.

Circulating Tumor Cell Phenotype Predicts Recurrence and Survival in Pancreatic Adenocarcinoma.

OBJECTIVE: We assessed circulating tumor cells (CTCs) with epithelial and mesenchymal phenotypes as a potential prognostic biomarker for patients with pancreatic adenocarcinoma (PDAC). BACKGROUND: PDAC is the fourth leading cause of cancer death in the United States. There is an urgent need to develop biomarkers that predict patient prognosis and allow for better treatment stratification. METHODS: Peripheral and portal blood samples were obtained from 50 patients with PDAC before surgical resection and filtered using the Isolation by Size of Epithelial Tumor cells method. CTCs were identified by immunofluorescence using commercially available antibodies to cytokeratin, vimentin, and CD45. RESULTS: Thirty-nine patients (78%) had epithelial CTCs that expressed cytokeratin but not CD45. Twenty-six (67%) of the 39 patients had CTCs which also expressed vimentin, a mesenchymal marker. No patients had cytokeratin-negative and vimentin-positive CTCs. The presence of cytokeratin-positive CTCs (P < 0.01), but not mesenchymal-like CTCs (P = 0.39), was associated with poorer survival. The presence of cytokeratin-positive CTCs remained a significant independent predictor of survival by multivariable analysis after accounting for other prognostic factors (P < 0.01). The detection of CTCs expressing both vimentin and cytokeratin was predictive of recurrence (P = 0.01). Among patients with cancer recurrence, those with vimentin-positive and cytokeratin-expressing CTCs had decreased median time to recurrence compared with patients without CTCs (P = 0.02). CONCLUSIONS: CTCs are an exciting potential strategy for understanding the biology of metastases, and provide prognostic utility for PDAC patients. CTCs exist as heterogeneous populations, and assessment should include phenotypic identification tailored to characterize cells based on epithelial and mesenchymal markers.

Reliable Detection of Somatic Mutations in Fine Needle Aspirates of Pancreatic Cancer With Next-generation Sequencing: Implications for Surgical Management.

OBJECTIVE: To determine the feasibility of genotyping pancreatic tumors via fine needle aspirates (FNAs). BACKGROUND: FNA is a common method of diagnosis for pancreatic cancer, yet it has traditionally been considered inadequate for molecular studies due to the limited quantity of DNA derived from FNA specimens and tumor heterogeneity. METHODS: In vitro mixing studies were performed to deduce the minimum cellularity needed for genetic analysis. DNA from both simulated FNAs and clinical FNAs was sequenced. Mutational concordance was determined between simulated FNAs and that of the resected specimen. RESULTS: Limiting dilution studies indicated that mutations present at allele frequencies as low as 0.12% are detectable. Comparison of simulated FNAs and matched tumor tissue exhibited a concordance frequency of 100% for all driver genes present. In FNAs obtained from 17 patients with unresectable disease, we identified at least 1 driver gene mutation in all patients including actionable somatic mutations in ATM and MTOR. The constellation of mutations identified in these patients was different than that reported for resectable pancreatic cancers, implying a biologic basis for presentation with locally advanced pancreatic cancer. CONCLUSIONS: FNA sequencing is feasible and subsets of patients may harbor actionable mutations that could potentially impact therapy. Moreover, preoperative FNA sequencing has the potential to influence the timing of surgery relative to systemic therapy. FNA sequencing opens the door to clinical trials in which patients undergo neoadjuvant or a surgery-first approach based on their tumor genetics with the goal of utilizing cancer genomics in the clinical management of pancreatic cancer.

Functional p38 MAPK identified by biomarker profiling of pancreatic cancer restrains growth through JNK inhibition and correlates with improved survival.

PURPOSE: Numerous biomarkers for pancreatic cancer have been reported. We determined the extent to which such biomarkers are expressed throughout metastatic progression, including those that effectively predict biologic behavior. EXPERIMENTAL DESIGN: Biomarker profiling was performed for 35 oncoproteins in matched primary and metastatic pancreatic cancer tissues from 36 rapid autopsy patients. Proteins of significance were validated by immunolabeling in an independent sample set, and functional studies were performed in vitro and in vivo. RESULTS: Most biomarkers were similarly expressed or lost in expression in most samples analyzed, and the matched primary and metastases from a specific patient were most similar to each other than to other patients. However, a subset of proteins showed extensive interpatient heterogeneity, one of which was p38 MAPK. Strong positive pp38 MAPK immunolabeling was significantly correlated with improved postresection survival by multivariate analysis (median overall survival 27.9 months, P = 0.041). In pancreatic cancer cells, inhibition of functional p38 by SB202190 increased cell proliferation in vitro in both low-serum and low-oxygen conditions. High functional p38 activity in vitro corresponded to lower levels of pJNK protein expression, and p38 inhibition resulted in increased pJNK and pMKK7 by Western blot analysis. Moreover, JNK inhibition by SP600125 or MKK7 siRNA knockdown antagonized the effects of p38 inhibition by SB202190. In vivo, SP600125 significantly decreased growth rates of xenografts with high p38 activity compared with those without p38 expression. CONCLUSIONS: Functional p38 MAPK activity contributes to overall survival through JNK signaling, thus providing a rationale for JNK inhibition in pancreatic cancer management.

Stromal elements act to restrain, rather than support, pancreatic ductal adenocarcinoma.

Sonic hedgehog (Shh), a soluble ligand overexpressed by neoplastic cells in pancreatic ductal adenocarcinoma (PDAC), drives formation of a fibroblast-rich desmoplastic stroma. To better understand its role in malignant progression, we deleted Shh in a well-defined mouse model of PDAC. As predicted, Shh-deficient tumors had reduced stromal content. Surprisingly, such tumors were more aggressive and exhibited undifferentiated histology, increased vascularity, and heightened proliferation--features that were fully recapitulated in control mice treated with a Smoothened inhibitor. Furthermore, administration of VEGFR blocking antibody selectively improved survival of Shh-deficient tumors, indicating that Hedgehog-driven stroma suppresses tumor growth in part by restraining tumor angiogenesis. Together, these data demonstrate that some components of the tumor stroma can act to restrain tumor growth.

Clinical significance of the genetic landscape of pancreatic cancer and implications for identification of potential long-term survivors.

PURPOSE: Genetic alterations of KRAS, CDKN2A, TP53, and SMAD4 are the most frequent events in pancreatic cancer. We determined the extent to which these 4 alterations are coexistent in the same carcinoma, and their impact on patient outcome. EXPERIMENTAL DESIGN: Pancreatic cancer patients who underwent an autopsy were studied (n = 79). Matched primary and metastasis tissues were evaluated for intragenic mutations in KRAS, CDKN2A, and TP53 and immunolabeled for CDKN2A, TP53, and SMAD4 protein products. The number of altered driver genes in each carcinoma was correlated to clinicopathologic features. Kaplan-Meier estimates were used to determine median disease free and overall survival, and a Cox proportional hazards model used to compare risk factors. RESULTS: The number of genetically altered driver genes in a carcinoma was variable, with only 29 patients (37%) having an alteration in all 4 genes analyzed. The number of altered driver genes was significantly correlated with disease free survival (P = 0.008), overall survival (P = 0.041), and metastatic burden at autopsy (P = 0.002). On multivariate analysis, the number of driver gene alterations in a pancreatic carcinoma remained independently associated with overall survival (P = 0.046). Carcinomas with only 1 to 2 driver alterations were enriched for those patients with the longest survival (median 23 months, range 1 to 53). CONCLUSIONS: Determinations of the status of the 4 major driver genes in pancreatic cancer, and specifically the extent to which they are coexistent in an individual patients cancer, provides distinct information regarding disease progression and survival that is independent of clinical stage and treatment status.

Small cell and large cell neuroendocrine carcinomas of the pancreas are genetically similar and distinct from well-differentiated pancreatic neuroendocrine tumors.

Poorly differentiated neuroendocrine carcinomas (NECs) of the pancreas are rare malignant neoplasms with a poor prognosis. The aim of this study was to determine the clinicopathologic and genetic features of poorly differentiated NECs and compare them with other types of pancreatic neoplasms. We investigated alterations of KRAS, CDKN2A/p16, TP53, SMAD4/DPC4, DAXX, ATRX, PTEN, Bcl2, and RB1 by immunohistochemistry and/or targeted exomic sequencing in surgically resected specimens of 9 small cell NECs, 10 large cell NECs, and 11 well-differentiated neuroendocrine tumors (PanNETs) of the pancreas. Abnormal immunolabeling patterns of p53 and Rb were frequent (p53, 18 of 19, 95%; Rb, 14 of 19, 74%) in both small cell and large cell NECs, whereas Smad4/Dpc4, DAXX, and ATRX labeling was intact in virtually all of these same carcinomas. Abnormal immunolabeling of p53 and Rb proteins correlated with intragenic mutations in the TP53 and RB1 genes. In contrast, DAXX and ATRX labeling was lost in 45% of PanNETs, whereas p53 and Rb immunolabeling was intact in these same cases. Overexpression of Bcl-2 protein was observed in all 9 small cell NECs (100%) and in 5 of 10 (50%) large cell NECs compared with only 2 of 11 (18%) PanNETs. Bcl-2 overexpression was significantly correlated with higher mitotic rate and Ki67 labeling index in neoplasms in which it was present. Small cell NECs are genetically similar to large cell NECs, and these genetic changes are distinct from those reported in PanNETs. The finding of Bcl-2 overexpression in poorly differentiated NECs, particularly small cell NEC, suggests that Bcl-2 antagonists/inhibitors may be a viable treatment option for these patients.