| 11. |
- Darmanis, Spyros, et al.
(författare)
-
Identification of Candidate Serum Proteins for Classifying Well-Differentiated Small Intestinal Neuroendocrine Tumors
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11, s. e81712-
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundPatients with well-differentiated small intestine neuroendocrine tumors (WD-SI-NET) are most often diagnosed at a metastatic stage of disease, which reduces possibilities for a curative treatment. Thus new approaches for earlier detection and improved monitoring of the disease are required.Materials and methodsSuspension bead arrays targeting 124 unique proteins with antibodies from the Human Protein Atlas were used to profile biotinylated serum samples. Discoveries from a cohort of 77 individuals were followed up in a cohort of 132 individuals both including healthy controls as well as patients with untreated primary WD-SI-NETs, lymph node metastases and liver metastases.Results A set of 20 antibodies suggested promising proteins for further verification based on technically verified statistical significance. Proceeding, we assessed the classification performance in an independent cohort of patient serum, achieving, classification accuracy of up to 85% with different subsets of antibodies in respective pairwise group comparisons. The protein profiles of nine targets, namely IGFBP2, IGF1, SHKBP1, ETS1, IL1α, STX2, MAML3, EGR3 and XIAP were verified as significant contributors to tumor classification.ConclusionsWe propose new potential protein biomarker candidates for classifying WD-SI-NET at different stage of disease. Further evaluation of these proteins in larger sample sets and with alternative approaches is needed in order to further improve our understanding of their functional relation to WD-SI-NET and their eventual use in diagnostics.
|
|
| 12. |
- Elgendy, Mohamed, et al.
(författare)
-
Dual modulation of MCL-1 and mTOR determines the response to sunitinib
- 2017
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 127:1, s. 153-168
-
Tidskriftsartikel (refereegranskat)abstract
- Most patients who initially respond to treatment with the multi-tyrosine kinase inhibitor sunitinib eventually relapse. Therefore, developing a deeper understanding of the contribution of sunitinib's numerous targets to the clinical response or to resistance is crucial. Here, we have shown that cancer cells respond to clinically relevant doses of sunitinib by enhancing the stability of the antiapoptotic protein MCL-1 and inducing mTORC1 signaling, thus evoking little cytotoxicity. Inhibition of MCL-1 or mTORC1 signaling sensitized cells to clinically relevant doses of sunitinib in vitro and was synergistic with sunitinib in impairing tumor growth in vivo, indicating that these responses are triggered as prosurvival mechanisms that enable cells to tolerate the cytotoxic effects of sunitinib. Furthermore, higher doses of sunitinib were cytotoxic, triggered a decline in MCL-1 levels, and inhibited mTORC1 signaling. Mechanistically, we determined that sunitinib modulates MCL-1 stability by affecting its proteasomal degradation. Dual modulation of MCL-1 stability at different dose ranges of sunitinib was due to differential effects on ERK and GSK3 beta activity, and the latter also accounted for dual modulation of mTORC1 activity. Finally, comparison of patient samples prior to and following sunitinib treatment suggested that increases in MCL-1 levels and mTORC1 activity correlate with resistance to sunitinib in patients.
|
|
| 13. |
- Essand, Magnus, et al.
(författare)
-
Identification and characterization of a novel splicing variant of vesicular monoamine transporter 1
- 2005
-
Ingår i: Journal of Molecular Endocrinology. - : Bioscientifica. - 0952-5041 .- 1479-6813. ; 35:3, s. 489-501
-
Tidskriftsartikel (refereegranskat)abstract
- Vesicular monoamine transporter 1 (VMAT1) is an integral protein in the membrane of secretory vesicles of neuroendocrine and endocrine cells that allows the transport of biogenic monoamines, such as serotonin, from the cytoplasm into the secretory vesicles. The full-length VMAT1 transcript is produced from 16 exons. We have identified and characterized an alternatively spliced form of VMAT1 that lacks exon 15, the next to last exon of VMAT1. The new form was therefore denoted VMAT1Delta15. Exon 15 does not contain an even multiple of three nucleotides. As a consequence, there is a shift of reading frame, and exon 16 is translated in an alternative reading frame, yielding a novel protein with a shorter and unrelated C-terminus compared with the native VMAT1 protein. VMAT1 and VMAT1Delta15 mRNAs are simultaneously expressed in normal and neoplastic neuroendocrine cells of the GI tract. However, VMAT1 expression is always higher than VMAT1Delta15 expression. We prove that VMAT1Delta15 is not localized in large, dense core vesicles as the native form but in the endoplasmic reticulum. Furthermore, while VMAT1 can take up serotonin, VMAT1Delta15 cannot, indicating different functions for the two forms of VMAT1.
|
|
| 14. |
- Essand, Magnus, et al.
(författare)
-
Oncolytic Viruses for the Treatment of Neuroendocrine Tumors
- 2011
-
Ingår i: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 0018-5043 .- 1439-4286. ; 43:12, s. 877-883
-
Forskningsöversikt (refereegranskat)abstract
- Oncolytic viruses are emerging as anticancer agents, and they have also shown great promise for use against neuroendocrine tumors. Many viruses have a natural tropism for replication in tumor cells. Others can be genetically engineered to selectively kill tumor cells. Viruses have some advantages as therapeutic agents over current cytotoxic drugs and small molecules. They replicate in tumor cells and thereby increase in number over time leading to increased dosage. They are immunogenic and can alter the immunosuppressive tumor microenvironment and activate immune effector cells. They have also been shown to be able to kill drug-resistant cancer stem cells. This article reviews the recent literature on oncolytic viruses used so far for neuroendocrine tumors and indicates important issues to focus on in the future.
|
|
| 15. |
- Giandomenico, Valeria, et al.
(författare)
-
Coactivator-dependent acetylation stabilizes members of the SREBP family of transcription factors
- 2003
-
Ingår i: Molecular and Cellular Biology. - 0270-7306 .- 1098-5549. ; 23:7, s. 2587-2599
-
Tidskriftsartikel (refereegranskat)abstract
- Members of the SREBP family of transcription factors control cholesterol and lipid homeostasis and play important roles during adipocyte differentiation. The transcriptional activity of SREBPs is dependent on the coactivators p300 and CBP. We now present evidence that SREBPs are acetylated by the intrinsic acetyltransferase activity of p300 and CBP. In SREBP1a, the acetylated lysine residue resides in the DNA-binding domain of the protein. Coexpression with p300 dramatically increases the expression of both SREBP1a and SREBP2, and this effect is dependent on the acetyltransferase activity of p300, indicating that acetylation of SREBPs regulates their stability. Indeed, acetylation or mutation of the acetylated lysine residue in SREBP1a stabilizes the protein. We demonstrate that the acetylated residue in SREBP1a is also targeted by ubiquitination and that acetylation inhibits this process. Thus, our studies define acetylation-dependent stabilization of transcription factors as a novel mechanism for coactivators to regulate gene expression.
|
|
| 16. |
- Giandomenico, Valeria, et al.
(författare)
-
Improving the Diagnosis and Management of Neuroendocrine Tumors : Utilizing New Advances in Biomarker and Molecular Imaging Science
- 2013
-
Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 98:1, s. 16-30
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroendocrine tumors (NET) are malignant solid tumors that arise in hormone-secreting tissue of the diffuse neuroendocrine system or endocrine glands. Although traditionally understood to be a rare disease, the incidence and prevalence of NET have increased greatly in the past 3 decades. However, during this time, progress in diagnosis and outcome of NET has generally been modest. In order to achieve improved outcome in NET, a better understanding of NET biology combined with more reliable serum markers and better techniques to identify tumor localization and small lesions are needed. Although some NET biomarkers exist, sensitive and specific markers that predict tumor growth and behavior are generally lacking. In addition, the integration of new molecular imaging technologies in patient diagnosis and follow-up has the potential to enhance care. To discuss developments and issues required to improve diagnostics and management of NET patients, with specific focus on the latest advances in molecular imaging and biomarker science, 17 global leaders in the fields of NET, molecular imaging and biomarker technology gathered to participate in a 2-day meeting hosted by Prof. Kjell Oberg at the University of Uppsala in Sweden. During this time, findings were presented regarding methods with potential prognostic and treatment applications in NET or other types of cancers. This paper describes the symposium presentations and resulting discussions.
|
|
| 17. |
- Giandomenico, Valeria, et al.
(författare)
-
Olfactory Receptor 51E1 as a Novel Target for Diagnosis in Somatostatin Receptor Negative Lung Carcinoids
- 2013
-
Ingår i: Journal of Molecular Endocrinology. - 0952-5041 .- 1479-6813. ; 51, s. 277-286
-
Tidskriftsartikel (refereegranskat)abstract
- Somatostatin receptors (SSTRs) may be used in lung carcinoids (LCs) for diagnosis and therapy, although additional targets are clearly warranted. This study aimed to investigate whether olfactory receptor 51E1 (OR51E1) may be a potential target for LCs. OR51E1 coding sequence was analyzed in LC cell lines, NCI-H727 and NCI-H720. OR51E1 transcript expression was investigated in LC cell lines and frozen specimens by quantitative real-time PCR. OR51E1, SSTR2, SSTR3, and SSTR5 expression was evaluated by immunohistochemistry on paraffin-embedded sections of 73 typical carcinoids (TCs), 14 atypical carcinoids (ACs) and 11 regional/distant metastases, and compared to OctreoScan data. Immunohistochemistry results were rendered semiquantitatively on a scale from 0 to 3+, taking into account the cellular compartmentalization (membrane vs. cytoplasm) and the percentage of tumor cells (<50% vs. >50%). Our results showed that wild-type OR51E1 transcript was expressed in both LC cell lines. OR51E1 mRNA was expressed in 9/12 TCs and 7/9 ACs (p=NS). Immunohistochemically, OR51E1, SSTR2, SSTR3 and SSTR5 were detected in 85%, 71%, 25% and 39% of TCs, and in 86%, 79%, 43% and 36% of ACs, respectively. OR51E1 immunohistochemical scores were higher or equal compared to SSTRs in 79% of TCs and 86% of ACs. Furthermore, in the LC cases where all SSTR subtypes were lacking, membrane OR51E1 expression was detected in 10/17 TCs and 1/2 ACs. Moreover, higher OR51E1 immunohistochemical scores were detected in 5/6 OctreoScan-negative LC lesions. Therefore, the high expression of OR51E1 in LCs makes it a potential novel diagnostic target in SSTR-negative tumors.
|
|
| 18. |
- Giandomenico, Valeria, et al.
(författare)
-
Other Novel Therapies : Biomarkers, microRNAs and microRNA Inhibitors, DNA Methylation, Epigenetics, Immunotherapy and Virotherapy
- 2015
-
Ingår i: Neuroendocrine Tumors. - : S. Karger. - 9783318027730 - 9783318027723 ; , s. 248-262
-
Bokkapitel (refereegranskat)abstract
- Neuroendocrine tumors (NETs) consist of heterogeneous neoplasms. The neuroendocrine cells of the human body are confined to certain organs, such as the thyroid, pancreas and adrenals, or they are dispersed throughout the body in the respiratory tract and in the intestinal mucosa. The cells belong to the diffuse endocrine cell system, share a neuroendocrine phenotype, and accumulate precursor molecules which are then processed into hormones, peptides or amines. The tightly controlled release on stimulation is either to the blood stream or adjacent cells or neurons. Neuroendocrine cells regulate various processes in the human body, such as gastrointestinal secretion, blood pressure and response to stress. NETs present a wide spectrum of malignant diseases from rather benign to very malignant and lethal variants. NETs may occur in any organ, but are mainly detected in the gastroenteropancreatic system and in the lungs. The understanding of NET biology and treatments has changed dramatically during the last decade. Today, the main problems that clinicians and translational scientists face in overcoming these malignancies relate to various aspects within the molecular pathogenesis of NETs. This chapter focuses on the importance of novel biomarkers: microRNA and microRNA inhibitors; DNA methylation and epigenetics, and immunotherapy and virotherapy to develop novel treatments for NETs.
|
|
| 19. |
- Leja, Justyna, et al.
(författare)
-
A novel chromogranin-A promoter-driven oncolytic adenovirus for midgut carcinoid therapy
- 2007
-
Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 13:8, s. 2455-2462
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: The use of replication-selective oncolytic adenoviruses is an emerging therapeutic approach for cancer, which thus far has not been employed for carcinoids. We therefore constructed Ad[CgA-E1A], a novel replication-selective oncolytic adenovirus, where the chromogranin A (CgA) promoter controls expression of the adenoviral E1A gene. Experimental Design: The Ad[CgA-E1A] virus was evaluated for E1A protein expression, replication ability, and cytolytic activity in various cell lines. It was also evaluated for treatment of xenografted human carcinoid tumors in nude mice. To use Ad[CgA-E1A] for the treatment of carcinoid liver metastases, it is important that normal hepatocytes do not support virus replication to minimize hepatotoxicity. We therefore evaluated CgA protein expression in normal hepatocytes. We also evaluated CgA gene expression in normal hepatocytes and microdissected tumor cells from carcinoid metastases. Results: We found that Ad[CgA-E1A] replicates similarly to wild-type virus in tumor cells with neuroendocrine features, including the BON carcinoid cell line and the SH-SY-5Y neuroblastoma cell lines, whereas it is attenuated in other cell types. Thus, cells where the CgA promoter is active are selectively killed. We also found that Ad[CgA-E1A] is able to suppress fast-growing human BON carcinoid tumors in nude mice. Furthermore, CgA is highly expressed in microdissected cells from carcinoid metastases, whereas it is not expressed in normal hepatocytes. Conclusion: Ad[CgA-E1A] is an interesting agent for the treatment of carcinoid liver metastases in conjunction with standard therapy for these malignancies.
|
|
| 20. |
- Leja, Justyna, et al.
(författare)
-
Double-detargeted oncolytic adenovirus shows replication arrest in liver cells and retains neuroendocrine cell killing ability
- 2010
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:1, s. e8916-
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:We have previously developed an oncolytic serotype 5 adenovirus (Ad5) with chromogranin-A (CgA) promoter-controlled E1A expression, Ad[CgA-E1A], with the intention to treat neuroendocrine tumors, including carcinoids. Since carcinoids tend to metastasize to the liver it is important to fully repress viral replication in hepatocytes to avoid adenovirus-related liver toxicity. Herein, we explore miRNA-based regulation of E1A expression as a complementary mechanism to promoter-based transcriptional control.METHODOLOGY/PRINCIPAL FINDINGS: Ad[CgA-E1A-miR122], where E1A expression is further controlled by six tandem repeats of the target sequence for the liver-specific miR122, was constructed and compared to Ad[CgA-E1A]. We observed E1A suppression and replication arrest of the miR122-detargeted adenovirus in normal hepatocytes, while the two viruses killed carcinoid cells to the same degree. Repeated intravenous injections of Ad[CgA-E1A] induced liver toxicity in mice while Ad[CgA-E1A-miR122] injections did not. Furthermore, a miR122-detargeted adenovirus with the wild-type E1A promoter showed reduced replication in hepatic cells compared to wild-type Ad5 but not to the same extent as the miR122-detargeted adenovirus with the neuroendocrine-selective CgA promoter.CONCLUSIONS/SIGNIFICANCE:A combination of transcriptional (promoter) and post-transcriptional (miRNA target) regulation to control virus replication may allow for the use of higher doses of adenovirus for efficient tumors treatment without liver toxicity.
|
|
