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| 2. |
- Deland, Lily, et al.
(author)
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Discovery of a rare GKAP1-NTRK2 fusion in a pediatric low-grade glioma, leading to targeted treatment with TRK-inhibitor larotrectinib
- 2021
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In: Cancer Biology & Therapy. - : Taylor & Francis. - 1538-4047 .- 1555-8576. ; 22:3, s. 184-195
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Journal article (peer-reviewed)abstract
- Here we report a case of an 11-year-old girl with an inoperable tumor in the optic chiasm/hypothalamus, who experienced several tumor progressions despite three lines of chemotherapy treatment. Routine clinical examination classified the tumor as a BRAF-negative pilocytic astrocytoma. Copy-number variation profiling of fresh frozen tumor material identified two duplications in 9q21.32–33 leading to breakpoints within the GKAP1 and NTRK2 genes. RT-PCR Sanger sequencing revealed a GKAP1-NTRK2 exon 10–16 in-frame fusion, generating a putative fusion protein of 658 amino acids with a retained tyrosine kinase (TK) domain. Functional analysis by transient transfection of HEK293 cells showed the GKAP1-NTRK2 fusion protein to be activated through phosphorylation of the TK domain (Tyr705). Subsequently, downstream mediators of the MAPK- and PI3K-signaling pathways were upregulated in GKAP1-NTRK2 cells compared to NTRK2 wild-type; phosphorylated (p)ERK (3.6-fold), pAKT (1.8- fold), and pS6 ribosomal protein (1.4-fold). Following these findings, the patient was enrolled in a clinical trial and treated with the specific TRK-inhibitor larotrectinib, resulting in the arrest of tumor growth. The patient’s condition is currently stable and the quality of life has improved significantly. Our findings highlight the value of comprehensive clinical molecular screening of BRAF-negative pediatric low-grade gliomas, to reveal rare fusions serving as targets for precision therapy.
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| 3. |
- Deland, Lily, et al.
(author)
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Novel TPR::ROS1 Fusion Gene Activates MAPK, PI3K and JAK/STAT Signaling in an Infant-type Pediatric Glioma.
- 2022
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In: Cancer genomics & proteomics. - : Anticancer Research USA Inc.. - 1109-6535 .- 1790-6245. ; 19:6, s. 711-726
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Journal article (peer-reviewed)abstract
- Although fusion genes involving the proto-oncogene receptor tyrosine kinase ROS1 are rare in pediatric glioma, targeted therapies with small inhibitors are increasingly being approved for histology-agnostic fusion-positive solid tumors.Here, we present a 16-month-old boy, with a brain tumor in the third ventricle. The patient underwent complete resection but relapsed two years after diagnosis and underwent a second operation. The tumor was initially classified as a low-grade glioma (WHO grade 2); however, methylation profiling suggested the newly WHO-recognized type: infant-type hemispheric glioma. To further refine the molecular background, and search for druggable targets, whole genome (WGS) and whole transcriptome (RNA-Seq) sequencing was performed.Concomitant WGS and RNA-Seq analysis revealed several segmental gains and losses resulting in complex structural rearrangements and fusion genes. Among the top-candidates was a novel TPR::ROS1 fusion, for which only the 3' end of ROS1 was expressed in tumor tissue, indicating that wild type ROS1 is not normally expressed in the tissue of origin. Functional analysis by Western blot on protein lysates from transiently transfected HEK293 cells showed the TPR::ROS1 fusion gene to activate the MAPK-, PI3K- and JAK/STAT- pathways through increased phosphorylation of ERK, AKT, STAT and S6. The downstream pathway activation was also confirmed by immunohistochemistry on tumor tissue slides from the patient.We have mapped the activated oncogenic pathways of a novel ROS1-fusion gene and broadened the knowledge of the newly recognized infant-type glioma subtype. The finding facilitates suitable targeted therapies for the patient in case of relapse.
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| 4. |
- Jurcevic, Sanja, 1971-, et al.
(author)
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Bioinformatics analysis of miRNAs in the neuroblastoma 11q-deleted region reveals a role of miR-548l in both 11q-deleted and MYCN amplified tumour cells
- 2022
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- Neuroblastoma is a childhood tumour that is responsible for approximately 15% of all childhood cancer deaths. Neuroblastoma tumours with amplification of the oncogene MYCN are aggressive, however, another aggressive subgroup without MYCN amplification also exists; rather, they have a deleted region at chromosome arm 11q. Twenty-six miRNAs are located within the breakpoint region of chromosome 11q and have been checked for a possible involvement in development of neuroblastoma due to the genomic alteration. Target genes of these miRNAs are involved in pathways associated with cancer, including proliferation, apoptosis and DNA repair. We could show that miR-548l found within the 11q region is downregulated in neuroblastoma cell lines with 11q deletion or MYCN amplification. In addition, we showed that the restoration of miR-548l level in a neuroblastoma cell line led to a decreased proliferation of these cells as well as a decrease in the percentage of cells in the S phase. We also found that miR-548l overexpression suppressed cell viability and promoted apoptosis, while miR-548l knockdown promoted cell viability and inhibited apoptosis in neuroblastoma cells. Our results indicate that 11q-deleted neuroblastoma and MYCN amplified neuroblastoma coalesce by downregulating miR-548l.
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| 5. |
- Keane, Simon, et al.
(author)
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DLG2 impairs dsDNA break repair and maintains genome integrity in neuroblastoma
- 2022
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In: DNA Repair. - : Elsevier. - 1568-7864 .- 1568-7856. ; 112
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Journal article (peer-reviewed)abstract
- BackgroundIn primary neuroblastoma, deletions on chromosome 11q are known to result in an increase in the total number of chromosomal breaks. The DNA double-strand break repair pathways mediated by NHEJ are often upregulated in cancer. DLG2, a candidate tumor suppressor gene on chromosome 11q, has previously been implicated in DNA repair.MethodsWe evaluated an association between gene expression and neuroblastoma patient outcome, risk categorization, and 11q status using publicly available microarray data from independent neuroblastoma patient datasets. Functional studies were conducted using comet assay and H2AX phosphorylation in neuroblastoma cell lines and in the fruit fly with UVC-induced DNA breaks.ResultsWe show that the NHEJ genes PARP1 and FEN1 are over expressed in neuroblastoma and restoration of DLG2 impairs their gene and protein expression. When exposed to UVC radiation, cells with DLG2 over expression show less DNA fragmentation and induce apoptosis in a p53 S46 dependent manner. We could also confirm that DLG2 over expression results in CHK1 phosphorylation consistent with previous reports of G2/M maintenance.ConclusionsTaken together, we show that DLG2 over expression increases p53 mediated apoptosis in response to etoposide and UVC mediated genotoxicity and reduced DNA replication machinery.
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| 6. |
- Keane, Simon, et al.
(author)
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Inflammation suppresses DLG2 expression decreasing inflammasome formation
- 2022
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In: Journal of Cancer Research and Clinical Oncology. - : Springer Science and Business Media LLC. - 0171-5216 .- 1432-1335. ; 148:9, s. 2295-2311
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Journal article (peer-reviewed)abstract
- Purpose Loss of expression of DLG2 has been identified in a number of cancers to contribute to the disease by resulting in increased tumor cell proliferation and poor survival. In light of the previous evidence that DLG2 alters the cell cycle and affects proliferation, combined with indications that DLG2 is involved in NLRP3 inflammasome axis we speculated that DLG2 has an immune function. So far, there is no data that clearly elucidates this role, and this study was designed to investigate DLG2 in inflammatory colon disease and in colon cancer as well as its impact on inflammasome induction. Methods The DLG2 expression levels were established in publicly available inflammation, colon cancer and mouse model datasets. The overexpression and silencing of DLG2 in colon cancer cells were used to determine the effect of DLG2 expression on the activation of the inflammasome and subsequent cytokine release. Results The expression of DLG2 is repressed in inflammatory colon diseases IBD and Ulcerative colitis as well as colorectal cancer tissue compared to healthy individuals. We subsequently show that induction with inflammatory agents in cell and animal models results in a biphasic alteration of DLG2 with an initial increase followed by an ensuing decrease. DLG2 overexpression leads to a significant increase in expression of IL1B, I kappa B zeta and BAX, components that result in inflammasome formation. DLG2 silencing in THP1 cells resulted in increased release of IL-6 into the microenvironment which once used to treat bystander COLO205 cells resulted in an increase in STAT3 phosphorylation and an increase proliferating cells and more cells in the G2/M phase. Restoration of DLG2 to the colon resulted in reduced AKT and S6 signaling. Conclusion DLG2 expression is altered in response to inflammation in the gut as well as colon cancer, resulting in altered ability to form inflammasomes.
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| 7. |
- Keane, Simon, et al.
(author)
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Low DLG2 gene expression, a link between 11q-deleted and MYCN-amplified neuroblastoma, causes forced cell cycle progression, and predicts poor patient survival
- 2020
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In: Cell Communication and Signaling. - : BioMed Central (BMC). - 1478-811X. ; 18:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Neuroblastoma (NB) is a childhood neural crest tumor. There are two groups of aggressive NBs, one with MYCN amplification, and another with 11q chromosomal deletion; these chromosomal aberrations are generally mutually exclusive. The DLG2 gene resides in the 11q-deleted region, thus makes it an interesting NB candidate tumor suppressor gene. METHODS: We evaluated the association of DLG2 gene expression in NB with patient outcomes, stage and MYCN status, using online microarray data combining independent NB patient data sets. Functional studies were also conducted using NB cell models and the fruit fly. RESULTS: Using the array data we concluded that higher DLG2 expression was positively correlated to patient survival. We could also see that expression of DLG2 was inversely correlated with MYCN status and tumor stage. Cell proliferation was lowered in both 11q-normal and 11q-deleted NB cells after DLG2 over expression, and increased in 11q-normal NB cells after DLG2 silencing. Higher level of DLG2 increased the percentage of cells in the G2/M phase and decreased the percentage of cells in the G1 phase. We detected increased protein levels of Cyclin A and Cyclin B in fruit fly models either over expressing dMyc or with RNAi-silenced dmDLG, indicating that both events resulted in enhanced cell cycling. Induced MYCN expression in NB cells lowered DLG2 gene expression, which was confirmed in the fly; when dMyc was over expressed, the dmDLG protein level was lowered, indicating a link between Myc over expression and low dmDLG level. CONCLUSION: We conclude that low DLG2 expression level forces cell cycle progression, and that it predicts poor NB patient survival. The low DLG2 expression level could be caused by either MYCN-amplification or 11q-deletion. Video Abstract.
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| 8. |
- Keane, Simon, 1991
(author)
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MOLECULAR AND GENETIC STUDIES OF DLG2 IN NEUROBLASTOMA AND COLORECTAL CANCER
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Neuroblastoma is one of the most common extra cranial solid tumors in children. It is one of the most common causes of death amongst the pediatric malignancies. There is however a large difference between the low risk neuroblastomas that are easier to treat compared to the high-risk neuroblastomas that are difficult to treat and account for a majority of the deaths. Two common groups of high-risk tumors have different genetic features, one with MYCN amplification and the other with loss of chromosome region 11q. Despite these two genetic alterations account for a high percentage of the total neuroblastoma cases they rarely occur together. Additionally, tumors with loss of 11q also tend to have decreased genome stability, resulting in increased DNA breakage. Currently, a number of candidate 11q tumor suppressor genes have been proposed, however, none of them have by themselves been able to explain the aggressive behavior of 11q-deleted neuroblastoma. For this reason, we identified and characterized DLG2, a novel tumor suppressor gene residing in the 11q-deleted region (Paper I). DLG2 resides on the reverse strand at the proximal edge of the 11q deleted region. We continued to show that there are a number of different isoforms of DLG2 with isoform 2 and isoform 7/8 the major isoforms expressed in neuroblastoma. The expression of isoform 2 remained stable so the decrease in DLG2 expression in neuroblastoma could be attributed to the loss of isoform 7/8, which alters the interactive ability of DLG2 (Paper II). In order to further elucidate the impact of DLG2 loss on DNA repair pathways, we investigated the relationship of DLG2 and genome stability by inducing dsDNA breaks by UVC irradiation or by etoposide, a topoisomerase II poison. We showed that loss of DLG2 was sufficient to result in dsDNA breaks without additional stimulus and that DNA break-age was prevented when DLG2 was present, by the removal of cells after the induction of breaks (Paper III). Finally, we showed that DLG2 was silenced by inflammation early in the development of colon cancer. We showed that DLG2 activated the inflammasome and resulted in a decrease in STAT3 phosphorylation in adjacent cells (Paper IV).
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| 9. |
- Keane, Simon, et al.
(author)
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The loss of DLG2 isoform 7/8, but not isoform 2, is critical in advanced staged neuroblastoma
- 2021
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In: Cancer Cell International. - : Springer Nature. - 1475-2867. ; 21:1
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Journal article (peer-reviewed)abstract
- Background: Neuroblastoma is a childhood neural crest tumor showing large clinical and genetic heterogeneity, one form displaying 11q-deletion is very aggressive. It has been shown that 11q-deletion results in decreased expression of DLG2, a gene residing in the deleted region. DLG2 has a number of different isoforms with the main difference is the presence or absence of a L27 domain. The L27 domain containing DLG proteins can form complexes with CASK/MPP and LIN7 protein family members, which will control cell polarity and signaling. Methods: We evaluated the DLG gene family and the LIN7 gene family for their expression in differently INSS staged neuroblastoma from publically available data and primary tumors, we included two distinct DLG1 and DLG2 N-terminal transcript isoforms encoding L27 domains for their expression. Functionality of DLG2 isoforms and of LIN7A were evaluated in the 11q-deleted neuroblastoma cell line SKNAS. Results: In neuroblastoma only two DLG2 isoforms were expressed: isoform 2 and isoform 7/8. Using the array data we could determine that higher expression of DLG members that contain L27 domains correlated to better survival and prognosis. Whilst DLG1 showed a decrease in both isoforms with increased INSS stage, only the full length L27 containing DLG2 transcripts DLG2-isoform 7/8 showed a decrease in expression in high stage neuroblastoma. We could show that the protein encoded by DLG2-isoform 7 could bind to LIN7A, and increased DLG2-isoform 7 gene expression increased the expression of LIN7A, this reduced neuroblastoma cell proliferation and viability, with increased BAX/BCL2 ratio indicating increased apoptosis. Conclusion: We have provided evidence that gene expression of the L27 domain containing DLG2-isoform 7/8 but not L27 domain lacking DLG2-isoform 2 is disrupted in neuroblastoma, in particular in the aggressive subsets of tumors. The presence of the complete L27 domain allows for the binding to LIN7A, which will control cell polarity and signaling, thus affecting cancer cell viability.
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| 10. |
- Pironi, Loris, et al.
(author)
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Characteristics of adult patients with chronic intestinal failure due to short bowel syndrome: An international multicenter survey
- 2021
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In: Clinical Nutrition ESPEN. - : Elsevier BV. - 2405-4577. ; 45, s. 433-441
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Journal article (peer-reviewed)abstract
- Background and aims: The case-mix of patients with intestinal failure due to short bowel syndrome (SBS-IF) can differ among centres and may also be affected by the timeframe of data collection. Therefore, the ESPEN international multicenter cross-sectional survey was analyzed to compare the characteristics of SBS-IF cohorts collected within the same timeframe in different countries. Methods: The study included 1880 adult SBS-IF patients collected in 2015 by 65 centres from 22 countries. The demographic, nutritional, SBS type (end jejunostomy, SBS-J; jejuno-colic anastomosis, SBS-JC; jejunoileal anastomosis with an intact colon and ileocecal valve, SBS-JIC), underlying disease and intravenous supplementation (IVS) characteristics were analyzed. IVS was classified as fluid and electrolyte alone (FE) or parenteral nutrition admixture (PN). The mean daily IVS volume, calculated on a weekly basis, was categorized as <1, 1–2, 2–3 and >3 L/day. Results: In the entire group: 60.7% were females and SBS-J comprised 60% of cases, while mesenteric ischaemia (MI) and Crohn’ disease (CD) were the main underlying diseases. IVS dependency was longer than 3 years in around 50% of cases; IVS was infused ≥5 days/week in 75% and FE in 10% of cases. Within the SBS-IF cohort: CD was twice and thrice more frequent in SBS-J than SBS-JC and SBS-JIC, respectively, while MI was more frequent in SBS-JC and SBS-JIC. Within countries: SBS-J represented 75% or more of patients in UK and Denmark and 50-60% in the other countries, except Poland where SBS-JC prevailed. CD was the main underlying disease in UK, USA, Denmark and The Netherlands, while MI prevailed in France, Italy and Poland. Conclusions: SBS-IF type is primarily determined by the underlying disease, with significant variation between countries. These novel data will be useful for planning and managing both clinical activity and research studies on SBS.
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