| 21. |
- Leja, Justyna, et al.
(författare)
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Novel markers for enterochromaffin cells and gastrointestinal neuroendocrine carcinomas
- 2009
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Ingår i: Modern Pathology. - : Elsevier BV. - 0893-3952 .- 1530-0285. ; 22:2, s. 261-272
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Tidskriftsartikel (refereegranskat)abstract
- The gene expression profile of metastasizing serotonin-producing neuroendocrine carcinomas, which arise from enterochromaffin cells in the jejunum and ileum, is still largely unknown. The aim of this study was to identify genes and proteins, which are preferentially expressed by neuroendocrine carcinoma and enterochromaffin cells and therefore potential novel biomarkers and/or therapeutic targets. Six carcinoma specimens and six normal ileal mucosas were profiled by Affymetrix microarrays. Advanced bioinformatics identified differentially and specifically expressed genes, which were validated by quantitative real-time-PCR on tumor cells extracted by laser capture microdissection and normal enterochromaffin cells extracted by immunolaser capture microdissection. We identified six novel marker genes for neuroendocrine carcinoma cells: paraneoplastic antigen Ma2 (PNMA2), testican-1 precursor (SPOCK1), serpin A10 (SERPINA10), glutamate receptor ionotropic AMPA 2 (GRIA2), G protein-coupled receptor 112 (GPR112) and olfactory receptor family 51 subfamily E member 1 (OR51E1). GRIA2 is specifically expressed by neuroendocrine carcinoma cells whereas the others are also expressed by normal enterochromaffin cells. GPR112 and OR51E1 encode proteins associated with the plasma membrane and may therefore become targets for antibody-based diagnosis and therapy. Hierarchical clustering shows high similarity between primary lesions and liver metastases. However, chemokine C-X-C motif ligand 14 (CXCL14) and NK2 transcription factor related locus 3 Drosophila (NKX2-3) are expressed to a lower level in liver metastases than in primary tumors and normal enterochromaffin cells, which implies a role in neuroendocrine carcinoma differentiation. In conclusion, this study provides a list of genes, which possess relatively specific expression to enterochromaffin and neuroendocrine carcinoma cells and genes with differential expression between primary tumors and metastases. We verified six novel marker genes that may be developed as biomarkers and/or therapeutic targets.
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| 22. |
- Leja, Justyna, et al.
(författare)
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Oncolytic adenovirus modified with somatostatin motifs for selective infection of neuroendocrine tumor cells
- 2011
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Ingår i: Gene Therapy. - : Springer Science and Business Media LLC. - 0969-7128 .- 1476-5462. ; 18:11, s. 1052-1062
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Tidskriftsartikel (refereegranskat)abstract
- We have previously described the oncolytic adenovirus, Ad(CgA-E1A-miR122), herein denoted Ad5(CgA-E1A-miR122) that selectively replicates in and kills neuroendocrine cells, including freshly isolated midgut carcinoid cells from liver metastases. Ad5(CgA-E1A-miR122) is based on human adenovirus serotype 5 (Ad5) and infects target cells by binding to the coxsackie-adenovirus receptor (CAR) and integrins on the cell surface. Some neuroendocrine tumor (NET) and neuroblastoma cells express low levels of CAR and are therefore poorly transduced by Ad5. However, they often express high levels of somatostatin receptors (SSTRs). Therefore, we introduced cyclic peptides, which contain four amino acids (FWKT) and mimic the binding site for SSTRs in the virus fiber knob. We show that FWKT-modified Ad5 binds to SSTR2 on NET cells and transduces midgut carcinoid cells from liver metastases about 3-4 times better than non-modified Ad5 while it transduces normal hepatocytes at about 50% of Ad5. Moreover, FWKT-modified Ad5 overcomes neutralization in an ex vivo human blood loop model to greater extent than Ad5, indicating that fiber knob modification may prolong the systematic circulation time. We conclude that modification of adenovirus with the FWKT motif may be beneficial for NET therapy.
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| 23. |
- Leja, Justyna, 1982-
(författare)
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Oncolytic Adenovirus Therapy of Neuroendocrine Tumors
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neuroendocrine tumors (NETs), originally described as carcinoids, represent a rare and heterogeneous group of neoplasms associated with intensive secretion of hormones, bioactive peptides and amines. Most of the patients are diagnosed at a late stage of disease, often with liver metastases. Surgery remains the main treatment to control metastatic disease, but is not curative. Oncolytic virotherapy represents a promising approach to treat cancer and different strategies have been exploited to restrict viral replication to tumor cells. We developed an oncolytic adenovirus based on serotype 5, Ad5[CgA-E1A], where the chromogranin A (CgA) promoter controls expression of the E1A gene and thereby virus replication. We found that Ad5[CgA-E1A], selectively replicates in NET cells and it is able to suppress fast-growing human BON carcinoid tumors in nude mice. The activity of Ad5[CgA-E1A] was not completely blocked in liver cells. We further repressed virus replication in hepatocytes by targeting E1A with miR122, an miRNA specifically expressed in the liver. miRNAs bind to mRNA and induce its cleavage or translational blockage. By insertion of tandem repeats of miR122 target sequences in 3’UTR of E1A gene, we observed reduced E1A protein expression and replication arrest in miR122 expressing liver cells. The oncolytic potency of the miR122-targeted virus was not affected in NET cells. Since some NET and neuroblastoma cells express high levels of somatostatin receptors (SSTRs), we introduced in the virus fiber knob cyclic peptides, which contain four amino acids (FWKT) and mimic the binding site of somatostatin for SSTRs. The FWKT-modified Ad5 transduces midgut carcinoid cells from liver metastases about 3-4 times better than non-modified Ad5. Moreover, FWKT-modified Ad5 overcomes neutralization in an ex vivo human blood loop model to a greater extent than Ad5, indicating that the fiber knob modification may prolong the systemic circulation time. NETs represent a huge therapeutic challenge and novel diagnostic markers are needed for early detection and effective treatment of NETs. We have profiled primary tumors and liver metastases of ileocaceal NETs, using Affymetrix microarrays and advanced bioinformatics. We have identified six novel marker genes and show high similarity between primary lesions and liver metastases transcriptome by hierarchical clustering analysis.
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| 24. |
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| 25. |
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| 26. |
- Li, Su-Chen, et al.
(författare)
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Global microRNA profiling of well-differentiated small intestinal neuroendocrine tumors.
- 2013
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Ingår i: Modern Pathology. - : Elsevier BV. - 0893-3952 .- 1530-0285. ; 26:5, s. 685-696
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Tidskriftsartikel (refereegranskat)abstract
- Well-differentiated small intestinal neuroendocrine tumors are rare malignancies. They arise from enterochromaffin cells and very little is known about differential microRNA (miRNA) expression. The aim of this study was to identify the miRNA profile of well-differentiated small intestinal neuroendocrine tumors, which may have a critical role in tumor development, progression and potentially develop miRNAs as novel clinical biomarkers. Specimens from two test groups, 24 small intestinal neuroendocrine tumor specimens at different stages of malignancy, are included in this study. Total RNA from the first test group, five primary tumors, five mesentery metastases and five liver metastases was hybridized onto the Affymetrix Genechip miRNA arrays to perform a genome-wide profile. The results were validated by using quantitative real-time PCR (QRT-PCR) and northern blot analyses. We then expanded the investigation to laser capture microdissected small intestinal neuroendocrine tumor cells and immuno-laser capture microdissected normal enterochromaffin cells of the first test group. Furthermore, a second test group, three primary tumors, three mesentery metastases and three liver metastases, was included in the study. Thus, two independent test groups validated the data by QRT-PCR. Moreover, we characterized nine miRNAs, five (miR-96, -182, -183, -196a and -200a), which are upregulated during tumor progression, whereas four (miR-31, -129-5p, -133a and -215) are downregulated. Several online software programs were used to predict potential miRNA target genes to map a number of putative target genes for the aberrantly regulated miRNAs, through an advanced and novel bioinformatics analysis. Our findings provide information about pivotal miRNAs, which may lead to further insights into tumorigenesis, progression mechanisms and novel therapeutic targets recognition.
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| 27. |
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| 28. |
- Li, Su-Chen, et al.
(författare)
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Roles of miR-196a on gene regulation of neuroendocrine tumor cells
- 2015
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Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 0303-7207 .- 1872-8057. ; 412:C, s. 131-139
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Tidskriftsartikel (refereegranskat)abstract
- This study aims at investigating miR-196a roles using in vitro models. miR-196a was detected in small intestinal neuroendocrine tumors (SI-NETS) and lung NETs. miR-196a target prediction analysis suggested HOXA9, HOXB7, LRP4 and RSPO2 genes for further investigation. The level of these four genes is detectable in SI-NET tissue specimens at different disease stages and serum samples of untreated and somatostatin analogs treated patients with liver metastases. A miR-196a inhibitor was used to silence its effects in NET cells. We show that the four target genes were significantly upregulated at transcriptional level in silenced NET cells. HOXA9, HOXB7, LRP4 and RSPO2 encoded proteins are also upregulated at translational level in miR-196a silenced NET cells. miR-196a downstream genes BMP4, ETS1, CTNNB1, FZD5, LEP5 and LRP6 were significantly upregulated at transcriptional level in miR-196a silenced CNDT2.5 and NCI-H727 cells. In addition, miR-196a clearly does not play a role in NET cell growth control.
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| 29. |
- Li, Su-Chen, 1979-
(författare)
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Small Intestinal Neuroendocrine Tumor Analyses : Somatostatin Analog Effects and MicroRNA Profiling
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small intestinal neuroendocrine tumors (SI-NETs) originate from serotonin-producing enterochromaffin (EC) cells in the intestinal mucosa. Somatostatin analogs (SSAs) are mainly used to control hormonal secretion and tumor growth. However, the molecular mechanisms leading to the control of SI-NETs are unknown. Although microRNAs (miRNAs) are post transcriptional regulators deeply studied in many cancers, are not well-defined in SI-NETs. We adopted a two-pronged strategy to investigate SSAs and miRNAs: first, to provide novel insights into how SSAs control NET cells, and second, to identify an exclusive SI-NET miRNA expression, and investigate the biological functions of miRNA targets.To accomplish the first aim, we treated CNDT2.5 cells with octreotide for 16 months. Affymetrix microarray was performed to study gene variation of CNDT2.5 cells in the presence or absence of octreotide. The study revealed that octreotide induces six genes, ANXA1, ARHGAP18, EMP1, GDF15, TGFBR2 and TNFSF15.To accomplish the second aim, SI-NET tissue specimens were used to run genome-wide Affymetrix miRNA arrays. The expression of five miRNAs (miR-96, -182, -183, -196a and -200a) was significantly upregulated in laser capture microdissected (LCM) tumor cells versus LCM normal EC cells, whereas the expression of four miRNAs (miR-31, -129-5p, -133a and -215) was significantly downregulated in LCM tumor cells. We also detected nine tissue miRNAs in serum samples, showing that the expression of five miRNAs is significantly increased in SSA treated patients versus untreated patients. Conversely, SSAs do not change miRNA expression of four low expressed miRNAs. Silencing miR-196a expression was used to investigate functional activities in NET cells. This experimental approach showed that four miR-196a target genes, HOXA9, HOXB7, LRP4 and RSPO2, are significantly upregulated in silenced miR-196a NET cells.In conclusion, ANXA1, ARHGAP18, EMP1, GDF15, TGFBR2 and TNFSF15 genes might regulate cell growth and differentiation in NET cells, and play a role in an innovative octreotide signaling pathway. The global SI-NET miRNA profiling revealed that nine selected miRNAs might be involved in tumorigenesis, and play a potential role as novel markers for follow-up. Indeed, silencing miR-196a demonstrated that HOXA9, HOXB7, LRP4 and RSPO2 genes are upregulated at both transcriptional and translational levels.
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| 30. |
- Li, Su-Chen, et al.
(författare)
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Somatostatin Analogs Treated Small Intestinal Neuroendocrine Tumor Patients Circulating MicroRNAs
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- We previously detected and investigated nine altered microRNAs in small intestinal neuroendocrine tumor (SI-NET) tissues at different stages of disease. The aims of this study are to: 1) analyze whether SI-NET tissue microRNAs can be also detected in patient serum samples, 2) investigate a potential somatostatin analogs (SSAs) role on microRNA levels regulation in SSA-treated patient samples and 3) elucidate whether the serum microRNA levels in samples collected in different hospitals are predictable and steady. Our results show that tissue microRNAs are detectable in patient serum samples, and miR-96, -182, -183, -196a and -200a levels are lower in SI-NET untreated patients than in SSA-treated patients at all different stages. Conversely, miR-31, -129-5p, -133a and -215 levels do not show any difference in untreated SI-NET patients and SSA-treated patients at all different stages. Our findings also show that miR-200a exhibits an atypical behavior with high levels in both untreated and SSA-treated patients at liver metastasis stage, and unequivocally never at the earlier stages. Serum samples collected in two hospitals keep alike microRNA level pattern, elucidating that the results are not dependent on samples handling. In conclusion, SI-NET tissue microRNAs are always detectable in untreated and SSA-treated patient serum samples, SSAs play an unknown role in eliciting SSA-treated patients' microRNA levels higher than in untreated patients, and this study enlightens that miR-200a might be involved in the liver metastasis during SI-NET progression.
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