A combination of surgery, theranostics, and liquid biopsy - a personalised oncologic approach to treatment of patients with advanced metastatic neuroendocrine neoplasms

Rationale: Neuroendocrine neoplasia (NEN) of small bowel (SBNEN) frequently present with metastatic disease. Theranostics (molecular imaging followed by targeting therapy) allow for personalised medicine. Liquid biopsies enable precise identification of residual disease and real-time monitoring of therapeutic response. Our aim was to determine the clinical utility of a combination of surgery, theranostics, and a multigene blood measurement in metastasised SBNEN. Methods: Inclusion criteria were SBNEN, G1/G2 NEN, initial tumour diagnosis, stage IV NEN, positivity on 68Ga somatostatin analogue PET/CT, eligible for surgery, and 177Lu peptide receptor radionuclide therapy (PRRT). Blood samples for NETest were collected longitudinally. Progression-free survival (PFS) and overall survival (OS) were calculated. NETest results were assessed prior to surgery and during clinical follow-up. Results: A surgical cohort of 39 SBNEN patients met eligibility criteria. Thirty-two patients underwent ileal resection and 7 right hemicolectomy. The mean number of 177Lu PRRT cycles was 4. Mortality was nil. Surgical morbidity was 10.3%. Transient grade 1/2 toxicity occurred in 41% (PRRT). NETest scores (n=9 patients) decreased in 100% following treatment and correlated with diminished tumour volume and disease stabilization following surgery and PRRT. Median follow-up: 78 months. Median PFS and OS: 42.7 and 110 months, respectively. Progression-free survival at 1-, 3-, and 5-years was 79.4%, 57.1% and 40.5%, respectively. Overall survival at 1-, 3-, and 5-years was 97.4%, 97.4%, and 94.1%, respectively. Conclusions: Surgery combined with 177Lu PRRT is safe and provides favourable PFS and OS in selected patients with advanced SBNEN. Liquid biopsy (NETest) has the potential to accurately delineate disease status

Suppression of Lung Adenocarcinoma Progression by Nkx2-1

Despite the high prevalence and poor outcome of patients with metastatic lung cancer the mechanisms of tumour progression and metastasis remain largely uncharacterized. Here we modelled human lung adenocarcinoma, which frequently harbours activating point mutations in KRAS and inactivation of the p53 pathway, using conditional alleles in mice. Lentiviral-mediated somatic activation of oncogenic Kras and deletion of p53 in the lung epithelial cells of Kras[superscript LSL-G12D/+];p53[superscript flox/flox] mice initiates lung adenocarcinoma development4. Although tumours are initiated synchronously by defined genetic alterations, only a subset becomes malignant, indicating that disease progression requires additional alterations. Identification of the lentiviral integration sites allowed us to distinguish metastatic from non-metastatic tumours and determine the gene expression alterations that distinguish these tumour types. Cross-species analysis identified the NK2-related homeobox transcription factor Nkx2-1 (also called Ttf-1 or Titf1) as a candidate suppressor of malignant progression. In this mouse model, Nkx2-1 negativity is pathognomonic of high-grade poorly differentiated tumours. Gain- and loss-of-function experiments in cells derived from metastatic and non-metastatic tumours demonstrated that Nkx2-1 controls tumour differentiation and limitsmetastatic potential in vivo. Interrogation of Nkx2-1-regulated genes, analysis of tumours at defined developmental stages, and functional complementation experiments indicate that Nkx2-1 constrains tumours in part by repressing the embryonically restricted chromatin regulator Hmga2. Whereas focal amplification of NKX2-1 in a fraction of human lung adenocarcinomas has focused attention on its oncogenic function, our data specifically link Nkx2-1 downregulation to loss of differentiation, enhanced tumour seeding ability and increased metastatic proclivity. Thus, the oncogenic and suppressive functions ofNkx2-1 in the sametumourNational Institutes of Health (U.S.) (grant U01-CA84306 )National Institutes of Health (U.S.) (grant K99-CA151968)Howard Hughes Medical InstituteLudwig Center for Molecular OncologyNational Cancer Institute (U.S.) (Cancer Center Support (core) grant P30-CA14051

A Conserved PHD Finger Protein and Endogenous RNAi Modulate Insulin Signaling in Caenorhabditis elegans

Insulin signaling has a profound effect on longevity and the oxidative stress resistance of animals. Inhibition of insulin signaling results in the activation of DAF-16/FOXO and SKN-1/Nrf transcription factors and increased animal fitness. By studying the biological functions of the endogenous RNA interference factor RDE-4 and conserved PHD zinc finger protein ZFP-1 (AF10), which regulate overlapping sets of genes in Caenorhabditis elegans, we identified an important role for these factors in the negative modulation of transcription of the insulin/PI3 signaling-dependent kinase PDK-1. Consistently, increased expression of pdk-1 in zfp-1 and rde-4 mutants contributed to their reduced lifespan and sensitivity to oxidative stress and pathogens due to the reduction in the expression of DAF-16 and SKN-1 targets. We found that the function of ZFP-1 in modulating pdk-1 transcription was important for the extended lifespan of the age-1(hx546) reduction-of-function PI3 kinase mutant, since the lifespan of the age-1; zfp-1 double mutant strain was significantly shorter compared to age-1(hx546). We further demonstrate that overexpression of ZFP-1 caused an increased resistance to oxidative stress in a DAF-16–dependent manner. Our findings suggest that epigenetic regulation of key upstream signaling components in signal transduction pathways through chromatin and RNAi may have a large impact on the outcome of signaling and expression of numerous downstream genes.Leukemia & Lymphoma Society of America (3260-07 Special Fellow Award)Arnold and Mabel Beckman Foundation (Young Investigator Award)United States. National Institutes of Health (Director's New Innovator Award (1 DP2 OD006412-01))United States. National Institutes of Health (grant GM66269)modENCODE (grant U01 HG004270)United States. National Institutes of Health (training grant 5T32 GM07088-34

Comparative Oncogenomic Analysis of Copy Number Alterations in Human and Zebrafish Tumors Enables Cancer Driver Discovery

The identification of cancer drivers is a major goal of current cancer research. Finding driver genes within large chromosomal events is especially challenging because such alterations encompass many genes. Previously, we demonstrated that zebrafish malignant peripheral nerve sheath tumors (MPNSTs) are highly aneuploid, much like human tumors. In this study, we examined 147 zebrafish MPNSTs by massively parallel sequencing and identified both large and focal copy number alterations (CNAs). Given the low degree of conserved synteny between fish and mammals, we reasoned that comparative analyses of CNAs from fish versus human MPNSTs would enable elimination of a large proportion of passenger mutations, especially on large CNAs. We established a list of orthologous genes between human and zebrafish, which includes approximately two-thirds of human protein-coding genes. For the subset of these genes found in human MPNST CNAs, only one quarter of their orthologues were co-gained or co-lost in zebrafish, dramatically narrowing the list of candidate cancer drivers for both focal and large CNAs. We conclude that zebrafish-human comparative analysis represents a powerful, and broadly applicable, tool to enrich for evolutionarily conserved cancer drivers.Kathy and Curt Marble Cancer Research FundArthur C. MerrillNational Institutes of Health (U.S.) (Grant CA106416)National Institutes of Health (U.S.) (Grant ROI RR020833)National Institutes of Health (U.S.) (Grant 1F32GM095213-01

On the involvement of Single-Bond Rotation in the Primary Photochemistry of Photoactive Yellow Protein

AbstractPrior experimental observations, as well as theoretical considerations, have led to the proposal that C4-C7 single-bond rotation may play an important role in the primary photochemistry of photoactive yellow protein (PYP). We therefore synthesized an analog of this protein's 4-hydroxy-cinnamic acid chromophore, (5-hydroxy indan-(1E)-ylidene)acetic acid, in which rotation across the C4-C7 single bond has been locked with an ethane bridge, and we reconstituted the apo form of the wild-type protein and its R52A derivative with this chromophore analog. In PYP reconstituted with the rotation-locked chromophore, 1), absorption spectra of ground and intermediate states are slightly blue-shifted; 2), the quantum yield of photochemistry is ∼60% reduced; 3), the excited-state dynamics of the chromophore are accelerated; and 4), dynamics of the thermal recovery reaction of the protein are accelerated. A significant finding was that the yield of the transient ground-state intermediate in the early phase of the photocycle was considerably higher in the rotation-locked samples than in the corresponding samples reconstituted with p-coumaric acid. In contrast to theoretical predictions, the initial photocycle dynamics of PYP were observed to be not affected by the charge of the amino acid residue at position 52, which was varied by 1), varying the pH of the sample between 5 and 10; and 2), site-directed mutagenesis to construct R52A. These results imply that C4-C7 single-bond rotation in PYP is not an alternative to C7=C8 double-bond rotation, in case the nearby positive charge of R52 is absent, but rather facilitates, presumably with a compensatory movement, the physiological Z/E isomerization of the blue-light-absorbing chromophore

Area of left ventricular regional conduction delay and preserved myocardium predict responses to cardiac resynchronization therapy

Cardiac Resynchronization Therapy. Background: A significant proportion of patients with dilated cardiomyopathy and left bundle branch block (LBBB) do not respond to cardiac resynchronization therapy (CRT). The purpose of this study was to investigate whether the electromechanical properties of the myocardium would predict acute hemodynamic improvement during left ventricular (LV) pacing. Methods and Results: We studied 10 patients with idiopathic dilated cardiomyopathy and LBBB (ejection fraction (EF): 27% ± 7%; QRS duration: 166 ± 16 msec) using three-dimensional electromechanical endocardial mapping technique to assess endocardial activation time (Endo-AT), unipolar voltage, and local linear shortening during sinus rhythm. LV stimulation was performed in VDD mode at five different sites and three atrioventricular delays within the coronary sinus. LV + dP/dtmax changes from baseline were measured during LV stimulation at each site (%ΔdP/dtmax). There was no significant relationship between maximum %AdP/dtmax during LV stimulation at the best coronary sinus site and LV EF, baseline LV + dP/dt max, total LV Endo-AT, baseline QRS duration nor changes in QRS duration during LV pacing. However, the maximum %AdP/dtmax was significantly positively correlated with percentage area of late Endo-AT (r = 0.97, P 20% of LV area with late Endo-AT and >30% of preserved LV myocardium had five times better acute hemodynamic response with LV stimulation. Multivariate analysis snowed that only percentage area of late Endo-AT was independently correlated with %AdP/dtmax (P < 0.05). Conclusion: The presence of a larger amount of LV area with late Endo-AT and preserved LV myocardium measured by electromechanical mapping could identify patients who have better acute improvement in systolic performance during LV stimulation.link_to_subscribed_fulltex