Systematic Evaluation of the Immune Environment of Small Intestinal Neuroendocrine Tumors

PURPOSE

The immune tumor microenvironment and the potential therapeutic opportunities for immunotherapy in small intestinal neuroendocrine tumors (siNET) have not been fully defined.

EXPERIMENTAL DESIGN

Herein, we studied 40 patients with primary and synchronous metastatic siNETs, and matched blood and normal tissue obtained during surgery. We interrogated the immune checkpoint landscape using multi-parametric flow cytometry. In addition, matched FFPE tissue was obtained for multi-parametric IHC to determine the relative abundance and distribution of T-cell infiltrate. Tumor mutational burden (TMB) was also assessed and correlated with immune infiltration.

RESULTS

Effector tumor-infiltrating lymphocytes (TIL) had a higher expression of PD-1 in the tumor microenvironment compared with the periphery. In addition, CD8+ TILs had a significantly higher co-expression of PD-1/ICOS and PD-1/CTLA-4 (cytotoxic T lymphocyte antigen-4) and higher levels of PD-1 expression compared with normal tissue. IHC revealed that the majority of cases have ≤10% intra-tumoral T cells but a higher number of peri-tumoral T cells, demonstrating an "exclusion" phenotype. Finally, we confirmed that siNETs have a low TMB compared with other tumor types in the TCGA database but did not find a correlation between TMB and CD8/Treg ratio.

CONCLUSIONS

Taken together, these results suggest that a combination therapy approach will be required to enhance the immune response, using PD-1 as a checkpoint immunomodulator backbone in combination with other checkpoint targeting molecules (CTLA-4 or ICOS), or with drugs targeting other pathways to recruit "excluded" T cells into the tumor microenvironment to treat patients with siNETs.

Whole-genome sequencing of single circulating tumor cells from neuroendocrine neoplasms

Single-cell profiling of circulating tumor cells (CTCs) as part of a minimally invasive liquid biopsy presents an opportunity to characterize and monitor tumor heterogeneity and evolution in individual patients. In this study, we aimed to compare single-cell copy number variation (CNV) data with tissue and define the degree of intra- and inter-patient genomic heterogeneity. We performed next-generation sequencing (NGS) whole-genome CNV analysis of 125 single CTCs derived from seven patients with neuroendocrine neoplasms (NEN) alongside matched white blood cells (WBC), formalin-fixed paraffin-embedded (FFPE), and fresh frozen (FF) samples. CTC CNV profiling demonstrated recurrent chromosomal alterations in previously reported NEN copy number hotspots, including the prognostically relevant loss of chromosome 18. Unsupervised hierarchical clustering revealed CTCs with distinct clonal lineages as well as significant intra- and inter-patient genomic heterogeneity, including subclonal alterations not detectable by bulk analysis and previously unreported in NEN. Notably, we also demonstrated the presence of genomically distinct CTCs according to the enrichment strategy utilized (EpCAM-dependent vs size-based). This work has significant implications for the identification of therapeutic targets, tracking of evolutionary change, and the implementation of CTC-biomarkers in cancer.

Circulating tumour cells and their association with bone metastases in patients with neuroendocrine tumours

Background

Bone metastases are associated with a worse outcome in patients with neuroendocrine tumours (NETs). Tumour overexpression of C-X-C chemokine receptor 4 (CXCR4) appears predictive of skeletal involvement. We investigated the role of circulating tumour cells (CTCs) and CXCR4 expression on CTCs as potential predictors of skeleton invasion.

Methods

Blood from patients with metastatic bronchial, midgut or pancreatic NET (pNET) was analysed by CellSearch. CXCR4 immunohistochemistry was performed on matched formalin-fixed paraffin-embedded (FFPE) samples.

Results

Two hundred and fifty-four patients were recruited with 121 midgut and 119 pNETs, of which 51 and 36% had detectable CTCs, respectively. Bone metastases were reported in 30% of midgut and 23% of pNET patients and were significantly associated with CTC presence (p = 0.003 and p < 0.0001). In a subgroup of 40 patients, 85% patients with CTCs had CTCs positive for CXCR4 expression. The proportion of CXCR4-positive CTCs in patients with bone metastases was 56% compared to 35% in those without (p = 0.18) it. Staining for CXCR4 on matched FFPE tissue showed a trend towards a correlation with CXCR4 expression on CTCs (p = 0.08).

Conclusions

CTC presence is associated with bone metastases in NETs. CXCR4 may be involved in CTC osteotropism and present a therapeutic target to reduce skeletal morbidity.

Type II Kinase Inhibitors Targeting Cys-Gatekeeper Kinases Display Orthogonality with Wild Type and Ala/Gly-Gatekeeper Kinases

Analogue-sensitive (AS) kinases contain large to small mutations in the gatekeeper position rendering them susceptible to inhibition with bulky analogues of pyrazolopyrimidine-based Src kinase inhibitors (e.g., PP1). This "bump-hole" method has been utilized for at least 85 of ∼520 kinases, but many kinases are intolerant to this approach. To expand the scope of AS kinase technology, we designed type II kinase inhibitors, ASDO2/6 (analogue-sensitive "DFG-out" kinase inhibitors 2 and 6), that target the "DFG-out" conformation of Cys-gatekeeper kinases with submicromolar potency. We validated this system in vitro against Greatwall kinase (GWL), Aurora-A kinase, and cyclin-dependent kinase-1 and in cells using M110C-GWL-expressing mouse embryonic fibroblasts. These Cys-gatekeeper kinases were sensitive to ASDO2/6 inhibition but not AS kinase inhibitor 3MB-PP1 and vice versa. These compounds, with AS kinase inhibitors, have the potential to inhibit multiple AS kinases independently with applications in systems level and translational kinase research as well as the rational design of type II kinase inhibitors targeting endogenous kinases.

Expression of somatostatin receptors 2 and 5 in circulating tumour cells from patients with neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours (NET) overexpress somatostatin receptors (SSTR) that can be targeted for therapy. Somatostatin receptor expression is routinely measured by molecular imaging but the resolution is insufficient to define heterogeneity. We hypothesised that SSTR expression could be measured on circulating tumour cells (CTCs) and used to investigate heterogeneity of expression and track changes during therapy.

METHODS

MCF-7 cells were transfected with SSTR2 or 5 and spiked into donor blood for analysis by CellSearch. Optimum anti-SSTR antibody concentration and exposure time were determined, and flow cytometry was used to evaluate assay sensitivity. For clinical evaluation, blood was analysed by CellSearch, and SSTR2/5 immunohistochemistry was performed on matched tissue samples.

RESULTS

Flow cytometry confirmed CellSearch was sensitive and that detection of SSTR was unaffected by the presence of somatostatin analogue up to a concentration of 100 ng ml-l. Thirty-one NET patients were recruited: grade; G1 (29%), G2 (45%), G3 (13%), primary site; midgut (58%), pancreatic (39%). Overall, 87% had SSTR-positive tumours according to somatostatin receptor scintigraphy or 68-Ga-DOTATE PET/CT. Circulating tumour cells were detected in 21 out of 31 patients (68%), of which 33% had evidence of heterogeneous expression of either SSTR2 (n=5) or SSTR5 (n=2).

CONCLUSIONS

Somatostatin receptors 2 and 5 are detectable on CTCs from NET patients and may be a useful biomarker for evaluating SSTR-targeted therapies and this is being prospectively evaluated in the Phase IV CALMNET trial (NCT02075606).

Abstract 5437: A novel method to quantify gamma H2AX foci in circulating tumor cells in patients receiving chemotherapy for colorectal cancer

Phosphorylated H2AX (γH2AX) is a marker of DNA double-strand break damage and has been proposed as a pharmacodynamic biomarker following treatment with chemotherapy. γH2AX levels in circulating tumor cells (CTCs) may provide a sensitive direct marker for assessing drug effects in tumor tissue without the need for biopsy. In the present study, we established a novel assay to quantify changes in γH2AX in CTCs from patients with metastatic colorectal cancers undergoing treatment with Fulfox or Folfiri. γH2AX foci were initially assessed in human colon adenocarcinoma cancer cell lines (HT-29) treated with different concentrations of Oxaliplatin and SN-38 at different time points. Image capture was conducted using Confocal Microscope Leica SPE2 and γH2AX foci were analyzed with CellProfiler software. The highest number of γH2AX foci/nucleus was induced at 5uM for Oxaliplatin and 0.01uM for SN-38 and the peak of γH2AX foci/nucleus was observed between two-six hours post dose. To reproduce the analytical process for CTCs, we evaluated the γH2AX signal using both the CellSearch System (Janssen Diagnostics) and the DEPArray™ System (Silicon Biosystems). HT-29 cells were used, either as untreated controls or following 2 hours treatment with Oxaliplatin 5uM or SN-38 0.01uM and spiked in to healthy donor blood. Cells were defined as positive for γH2AX on the CellSearch according to a previously validated assay. For Oxaliplatin and SN-38 treated cells, 15.28% and 18.37% respectively were classified as positive for γH2AX, compared with 5.10% for untreated controls. However, using CellSearch, the fluorescent signal could not be quantified and we therefore repeated the experiment using the DEPArray platform. HT-29 cells were treated with SN-38 as above, and compared with an untreated control group using two different exposure times for fluorescein isothiocyanate-conjugated antibody (FITC): FITCI (100 ms and gain 1X) and FITCII (800 ms and gain 4X). The treated group showed a significantly increased intensity of FITC staining compared with the untreated control group: mean 363 vs mean 220 (p&lt;0.0001) for FITCI, and mean 5521 vs mean 4365 (p&lt;0.0040) for FITCII. The DEPArray system therefore has an advantage in being able to quantify differences in signal intensity caused by induction of γH2AX in CTCs and then select individual cells for further downstream analysis. This analysis is now being applied to patient samples collected pre and post-chemotherapy to evaluate the utility of the assay in a clinical setting.

Citation Format: Matilde Saggese, Leah Ensell, Clare Vesely, Victoria Spanswick, Elena Peruzzi, Diana Cunati, Giulio Signorini, John Hartley, Hendrik Tobias Arkenau, Tim Meyer. A novel method to quantify gamma H2AX foci in circulating tumor cells in patients receiving chemotherapy for colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5437. doi:10.1158/1538-7445.AM2015-5437

PP2A/B55 and Fcp1 regulate Greatwall and Ensa dephosphorylation during mitotic exit

Entry into mitosis is triggered by activation of Cdk1 and inactivation of its counteracting phosphatase PP2A/B55. Greatwall kinase inactivates PP2A/B55 via its substrates Ensa and ARPP19. Both Greatwall and Ensa/ARPP19 are regulated by phosphorylation, but the dynamic regulation of Greatwall activity and the phosphatases that control Greatwall kinase and its substrates are poorly understood. To address these questions we applied a combination of mathematical modelling and experiments using phospho-specific antibodies to monitor Greatwall, Ensa/ARPP19 and Cdk substrate phosphorylation during mitotic entry and exit. We demonstrate that PP2A/B55 is required for Gwl dephosphorylation at the essential Cdk site Thr194. Ensa/ARPP19 dephosphorylation is mediated by the RNA Polymerase II carboxy terminal domain phosphatase Fcp1. Surprisingly, inhibition or depletion of neither Fcp1 nor PP2A appears to block dephosphorylation of the bulk of mitotic Cdk1 substrates during mitotic exit. Taken together our results suggest a hierarchy of phosphatases coordinating Greatwall, Ensa/ARPP19 and Cdk substrate dephosphorylation during mitotic exit.

Differential control of Eg5-dependent centrosome separation by Plk1 and Cdk1

Cyclin-dependent kinase 1 (Cdk1) is thought to trigger centrosome separation in late G2 phase by phosphorylating the motor protein Eg5 at Thr927. However, the precise control mechanism of centrosome separation remains to be understood. Here, we report that in G2 phase polo-like kinase 1 (Plk1) can trigger centrosome separation independently of Cdk1. We find that Plk1 is required for both C-Nap1 displacement and for Eg5 localization on the centrosome. Moreover, Cdk2 compensates for Cdk1, and phosphorylates Eg5 at Thr927. Nevertheless, Plk1-driven centrosome separation is slow and staggering, while Cdk1 triggers fast movement of the centrosomes. We find that actin-dependent Eg5-opposing forces slow down separation in G2 phase. Strikingly, actin depolymerization, as well as destabilization of interphase microtubules (MTs), is sufficient to remove this obstruction and to speed up Plk1-dependent separation. Conversely, MT stabilization in mitosis slows down Cdk1-dependent centrosome movement. Our findings implicate the modulation of MT stability in G2 and M phase as a regulatory element in the control of centrosome separation.

Remission of severe tardive dyskinesia in a schizophrenic patient treated with the atypical antipsychotic substance quetiapine

In a single inpatient case study, a schizophrenic patient with tardive dyskinesia after prolonged treatment with typical neuroleptics was treated with the new atypical neuroleptic quetiapine, a dibenzothiazepin-derivative. Within 2 weeks of treatment with quetiapine, symptoms of tardive dyskinesia improved; 10 weeks after starting treatment tardive dyskinesia stopped completely. Over the same period, dopamine D2 receptor occupancy decreased substantially, as measured by IBZM-SPECT after 14 and 77 days of treatment.

Psychosocial factors in children and adolescents with migraine and tension-type headache: a controlled study and review of the literature

We investigated 341 children and adolescents to evaluate the relevance of psychosocial factors in idiopathic headache. According to the criteria of the International Headache Society, 151 subjects had migraine and 94 had tension-type headache (TTH). Ninety-six subjects were headache-free controls. Psychosocial factors covered family and housing conditions, school problems, relations in the peer group, and several other items. We found that migraine patients did not differ from headache-free controls. Patients with TTH more often had divorced parents than the headache-free controls, and they had fewer peer relations than migraineurs and controls. In addition, migraine patients were significantly more often absent from school due to headache. All other psychosocial factors failed to discriminate between the three study groups. In conclusion, this controlled study in children and adolescents suggests that migraine is not related to family and housing conditions, school situation, or peer relations, whereas TTH is associated with a higher rate of divorced parents and fewer peer relations.

IBZM SPECT imaging of striatal dopamine-2 receptors in psychotic patients treated with the novel antipsychotic substance quetiapine in comparison to clozapine and haloperidol

We investigated the striatal dopamine-2 (D2) receptor occupancy caused by different antipsychotic substances in 18 psychotic patients (16 with schizophrenic and two with schizoaffective disorder according to DSM-IV) with single photon emission computed tomography (SPECT) using 123I-iodobenzamide (IBZM) as tracer substance. Four patients were treated with the novel antipsychotic compound quetiapine (300-700 mg/day), six with clozapine (300-600 mg/ day) and eight with haloperidol (10-20 mg/day). They were compared with eight healthy controls. Measurement of S/F ratios and consecutive calculation of D2 receptor occupancy revealed a significantly lower striatal D2 occupancy rate with quetiapine and clozapine in comparison to haloperidol. In correspondence with the low striatal D2 receptor occupancy rates and again in contrast to the haloperidol treatment group, there were no extrapyramidal motor side-effects (EPS) in the quetiapine and clozapine treatment groups. Therefore, the reported data support the position that quetiapine can be considered to be an atypical antipsychotic substance due to its relatively weak striatal D2 receptor blocking property and therefore its low propensity to induce EPS.

Striatal dopamine-2 receptor occupancy in psychotic patients treated with risperidone

Seventeen psychiatric patients (11 with schizophrenia, 5 with other psychotic disorders, and 1 with obsessive-compulsive disorder) were examined by single photon emission computed tomography with 123I-iodobenzamide (IBZM) as tracer. Patients were treated with risperidone in two different dosage groups (3 mg and 8 mg) and haloperidol (10-20 mg) and compared with eight healthy control subjects. There was a statistically significant difference in basal ganglia/frontal cortex ratios of IBZM binding between controls and all treatment groups. A statistically significant difference was also found concerning these ratios and percentage of dopamine D2 receptor occupancy rates between the treatment groups with lowest ratios and highest percentage of D2 receptor occupancy in the group of patients treated with haloperidol, followed by the group treated with 8 mg of risperidone and the group treated with 3 mg of risperidone.

IHS criteria and gender: a study on migraine and tension-type headache in children and adolescents

The aim of this study was to investigate whether the IHS criteria for migraine and tension-type headache depend on gender. Among 409 children and adolescents with recurrent idiopathic headache seen at a university outpatient clinic, girls had significantly more often migraine with aura. Also, there was a trend towards a higher frequency of tension-type headache in girls. In migraine, aggravation of headache by physical activity and occurrence of aura symptoms were more common in females, whereas vomiting and phonophobia occurred more often in males. In tension-type headache, females more often reported mild intensity of headache. All other criteria were similar in both sexes. Age influenced the expression of some of the accompanying symptoms in the various types of migraine, but had only minimal influence on other diagnostic criteria of migraine and tension-type headache in females as well as in males. Our study suggests that the frequency of migraine (except that of migraine with aura) is similar among girls and boys, that tension-type headache may occur more often in girls, and that gender has some influence on the IHS criteria for migraine, but almost no influence on those of tension-type headache.

IHS criteria for migraine and tension-type headache in children and adolescents

We investigated the influence of age on the IHS criteria for migraine and tension-type headache in 437 consecutive children and adolescents and found the following age-associated statistically significant differences: migraine duration, occurrence of migraine aura, and bilateral location of tension-type headache were more often fulfilled by adolescents, whereas aggravation of headache by physical activity (in migrainous disorder) and photophobia (in migraine with aura) were more often fulfilled by children. Accordingly, there are only a few differences concerning the fulfillment of the IHS criteria for migraine and tension-type headache in children and adolescents. Independent of age, the intensity of headache and the presence or absence of nausea are most important for differentiating the two major types of idiopathic headache. The sensitivity of the IHS criteria for migraine could be increased by reducing the minimum duration of migraine and by allowing the diagnosis of migraine when severe headache is associated with nausea, even though the criteria of location, quality, and aggravation by physical activity are not fulfilled.

Magnetic resonance imaging for recurrent headache in childhood and adolescence

We investigated 429 consecutive patients, aged 5 to 18 (mean: 11.0 +/- 3.1) years, diagnosed with migraine or tension-type headache. The patients underwent either MRI or exclusively clinical follow-up examinations. Magnetic resonance imaging revealed normal findings in 82.3% and structural changes in 17.7%. However, the vast majority of these changes had minimal or no pathological relevance, and a causal relationship to the patient's headache could not be proven in any case. In the non-MRI group, clinical follow-up examinations confirmed the initial diagnosis in all patients and MRI was not required in any of these subjects. In conclusion, our study shows a poor relation between recurrent headache fulfilling the criteria of migraine and tension-type headache and structural changes incidentally detected by MRI. In addition, it suggests that clinical follow-up examinations are reliable. Accordingly, MRI is not required for routine examination of recurrent headache in children and adolescents, but it should be performed in patients with abnormal neurological findings, atypical headache pattern, or significant change of preexisting headache.

Pediatric patient-controlled analgesia: enhancing the self-care construct

A review and research critique of nine medical and nursing studies indicates the successful use of pediatric patient-controlled analgesia (PCA). Orem's Self-Care Construct theoretically provides a nursing framework for analysis of these studies. Additionally, parental involvement in their child's pain control experience is examined, implying a new arena for nursing research.

Diagnosis of headache in childhood and adolescence: a study in 437 patients

We investigated whether the criteria for idiopathic headache published by the International Headache Society (IHS) are useful in childhood and adolescence and compared the diagnoses according to this classification with those of Vahlquist. We used a semi-structured questionnaire to examine a total of 437 children and adolescents referred consecutively to a headache outpatient clinic. Twenty-eight of 437 patients were excluded because of symptomatic or unclassifiable headache. Of 409 patients with idiopathic headache, 70.4% had definite migraine or tension-type headache (IHS 1.1, 1.2, 2.1, 2.2), 20.5% had a migrainous disorder (IHS 1.7) and 9.1% had headache of the tension-type not fulfilling the criteria (IHS 2.3). In the differential diagnosis of migraine and tension-type headache the intensity of pain, aggravation of headache by physical activity, nausea and vomiting were the most important features. The quality of pain, photo- and phonophobia were less helpful and location least important. The duration of migraine attacks was less than 2 h in 19.0% of the migraine patients. In general, the diagnostic criteria of migraine were highly specific but less sensitive, and those of tension-type headache highly sensitive but less specific. The agreement between IHS criteria and those of Vahlquist was marked (kappa = 0.57). We conclude that the IHS criteria are useful for classifying headache in children and adolescents referred to a headache outpatient clinic. A forthcoming modification of the IHS criteria should consider a reduction of the minimum duration of migraine attacks from 2 h to 1 h and should try to increase the sensitivity of the criteria for migraine and the specificity of the criteria for tension-type headache.