| 1. |
- Elsir, Tamador, et al.
(författare)
-
A study of embryonic stem cell-related proteins in human astrocytomas : Identification of Nanog as a predictor of survival
- 2014
-
Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 134:5, s. 1123-1131
-
Tidskriftsartikel (refereegranskat)abstract
- Recent studies suggest that the regulatory networks controlling the functions of stem cells during development may be abnormally active in human cancers. An embryonic stem cell (ESC) gene signature was found to correlate with a more undifferentiated phenotype of several human cancer types including gliomas, and associated with poor prognosis in breast cancer. In the present study, we used tissue microarrays of 80 low-grade (WHO grade II) and 98 high-grade human gliomas (WHO grade III and IV) to investigate the presence of the ESC-related proteins Nanog, Klf4, Oct4, Sox2 and c-Myc by immunohistochemistry. While similar patterns of co-expressed proteins between low- and high-grade gliomas were present, we found up-regulated protein levels of Nanog, Klf4, Oct4 and Sox2 in high-grade gliomas. Survival analysis by Kaplan-Meier analysis revealed a significant shorter survival in the subgroups of low-grade astrocytomas (n=42) with high levels of Nanog protein (p=0.0067) and of Klf4 protein (p=0.0368), in high-grade astrocytomas (n=85) with high levels of Nanog (p=0.0042), Klf4 (p=0.0447), and c-Myc (p=0.0078) and in glioblastomas only (n=71) with high levels of Nanog (p=0.0422) and of c-Myc (p= 0.0256). In the multivariate model, Nanog was identified as an independent prognostic factor in the subgroups of low-grade astrocytomas (p=0.0039), high-grade astrocytomas (p=0.0124) and glioblastomas only (p=0.0544), together with established clinical variables in these tumors. These findings provide further evidence for the joint regulatory pathways of ESC-related proteins in gliomas and identify Nanog as one of the key players in determining clinical outcome of human astrocytomas.
|
|
| 2. |
- Elsir, Tamador, et al.
(författare)
-
Transcription factor PROX1 : its role in development and cancer.
- 2012
-
Ingår i: Cancer Metastasis Review. - : Springer Science and Business Media LLC. - 0167-7659 .- 1573-7233. ; 31:3-4, s. 793-805
-
Forskningsöversikt (refereegranskat)abstract
- The homeobox gene PROX1 is critical for organ development during embryogenesis. The Drosophila homologue, known as prospero has been shown to act as a tumor suppressor by controlling asymmetric cell division of neuroblasts. Likewise, alterations in PROX1 expression and function are associated with a number of human cancers including hematological malignancies, carcinomas of the pancreas, liver and the biliary system, sporadic breast cancer, Kaposiform hemangioendothelioma, colon cancer, and brain tumors. PROX1 is involved in cancer development and progression and has been ascribed both tumor suppressive and oncogenic properties in a variety of different cancer types. However, the exact mechanisms through which PROX1 regulates proliferation, migration, and invasion of cancer cells are by large unknown. This review provides an update on the role of PROX1 in organ development and on its emerging functions in cancer, with special emphasis on the central nervous system and glial brain tumors.
|
|
| 3. |
- Gadalla, Salah-Eldin, et al.
(författare)
-
EpCAM associates with endoplasmic reticulum aminopeptidase 2 (ERAP2) in breast cancer cells
- 2013
-
Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 439:2, s. 203-208
-
Tidskriftsartikel (refereegranskat)abstract
- Epithelial cell adhesion molecule (EpCAM) is an epithelial and cancer cell marker and there is a cumulative and growing evidence of its signaling role. Its importance has been recognized as part of the breast cancer stem cell phenotype, the tumorigenic breast cancer stem cell is EpCAM(+). In spite of its complex functions in normal cell development and cancer, relatively little is known about EpCAM-interacting proteins. We used breast cancer cell lines and performed EpCAM co-immunoprecipitation followed by mass spectrometry in search for novel potentially interacting proteins. The endoplasmic reticulum aminopeptidase 2 (ERAP2) was found to co-precipitate with EpCAM and to co-localize in the cytoplasm/ER and the plasma membrane. ERAP2 is a proteolytic enzyme set in the endoplasmic reticulum (ER) where it plays a central role in the trimming of peptides for presentation by MHC class I molecules. Expression of EpCAM and ERAP2 in vitro in the presence of dog pancreas rough microsomes (ER vesicles) confirmed N-linked glycosylation, processing in ER and the size of EpCAM. The association between ERAP2 and EpCAM is a unique and novel finding that provides new ideas on EpCAM processing and on how antigen presentation may be regulated in cancer.
|
|
| 4. |
- Hagerstrand, Daniel, et al.
(författare)
-
Identification of a SOX2-dependent subset of tumor- and sphere-forming glioblastoma cells with a distinct tyrosine kinase inhibitor sensitivity profile
- 2011
-
Ingår i: Neuro-Oncology. - : Oxford University Press (OUP). - 1522-8517 .- 1523-5866. ; 13:11, s. 1178-1191
-
Tidskriftsartikel (refereegranskat)abstract
- Putative cancer stem cells have been identified in glioblastomas and are associated with radio- and chemoresistance. Further knowledge about these cells is thus highly warranted for the development of better glioblastoma therapies. Gene expression analyses of 11 high-grade glioma cultures identified 2 subsets, designated type A and type B cultures. The type A cultures displayed high expression of CXCR4, SOX2, EAAT1, and GFAP and low expression of CNP, PDGFRB, CXCL12, and extracellular matrix proteins. Clinical significance of the 2 types was indicated by the expression of type A-and type B-defining genes in different clinical glioblastoma samples. Classification of glioblastomas with type A- and type B-defining genes generated 2 groups of tumors composed predominantly of the classical, neural, and/or proneural subsets and the mesenchymal subset, respectively. Furthermore, tumors with EGFR mutations were enriched in the group of type A samples. Type A cultures possessed a higher capacity to form xenograft tumors and neurospheres and displayed low or no sensitivity to monotreatment with PDGF-and IGF-1-receptor inhibitors but were efficiently growth inhibited by combination treatment with low doses of these 2 inhibitors. Furthermore, siRNA-induced downregulation of SOX2 reduced sphere formation of type A cultures, decreased expression of type A-defining genes, and conferred sensitivity to monotreatment with PDGF-and IGF-1receptor inhibitors. The present study thus describes a tumor-and neurosphere-forming SOX2-dependent subset of glioblastoma cultures characterized by a gene expression signature similar to that of the recently described classical, proneural, and/or neural subsets of glioblastoma. The findings that resistance to PDGF-and IGF-1-receptor inhibitors is related to SOX2 expression and can be overcome by combination treatment should be considered in ongoing efforts to develop novel stem cell-targeting therapies.
|
|
| 5. |
- Holmberg, Johan, et al.
(författare)
-
Activation of Neural and Pluripotent Stem Cell Signatures Correlates with Increased Malignancy in Human Glioma
- 2011
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:3, s. e18454-
-
Tidskriftsartikel (refereegranskat)abstract
- The presence of stem cell characteristics in glioma cells raises the possibility that mechanisms promoting the maintenance and self-renewal of tissue specific stem cells have a similar function in tumor cells. Here we characterized human gliomas of various malignancy grades for the expression of stem cell regulatory proteins. We show that cells in high grade glioma co-express an array of markers defining neural stem cells (NSCs) and that these proteins can fulfill similar functions in tumor cells as in NSCs. However, in contrast to NSCs glioma cells co-express neural proteins together with pluripotent stem cell markers, including the transcription factors Oct4, Sox2, Nanog and Klf4. In line with this finding, in high grade gliomas mesodermal-and endodermal-specific transcription factors were detected together with neural proteins, a combination of lineage markers not normally present in the central nervous system. Persistent presence of pluripotent stem cell traits could only be detected in solid tumors, and observations based on in vitro studies and xenograft transplantations in mice imply that this presence is dependent on the combined activity of intrinsic and extrinsic regulatory cues. Together these results demonstrate a general deregulated expression of neural and pluripotent stem cell traits in malignant human gliomas, and indicate that stem cell regulatory factors may provide significant targets for therapeutic strategies.
|
|
| 6. |
- Holmlund, Camilla, 1969-
(författare)
-
Identification and investigations of leucine-rich repeats and immunoglobulin-like domains protein 2 (LRIG2)
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Receptor tyrosine kinases (RTKs) constitute a family of proteins controlling cell growth and proliferation and whose activities are tightly controlled in normal cells. LRIG1 is a negative regulator of RTK signaling and is a proposed tumor suppressor. The aim of this thesis was to identify and study possible paralogs of LRIG1. By using the basic local alignment search tool and cDNA cloning, a human mRNA sequence with similarity to LRIG1 was identified and named LRIG2. By fluorescence in situ hybridization analysis, LRIG2 was found to reside on chromosome 1p13. The LRIG2 amino acid sequence was 47% identical to LRIG1, and the predicted protein domain organization was the same as that of LRIG1. Antibodies against LRIG2 were developed and the apparent molecular weight of the protein was determined to be 132 kDa by SDS-polyacrylamide gel electrophoresis and Western blot analysis. The sub-cellular localization was studied by cell surface biotinylation experiments and confocal fluorescence laser microscopy, which revealed that LRIG2 resided at the cell surface and in the cytoplasm. The expression patterns of LRIG2 mRNA, during development and in adult tissues, were evaluated using whole-mount in situ hybridization and quantitative real-time RT-PCR, respectively. In E10.5, E11.5 and E12.5 mouse embryos, the Lrig2 expression domains were both overlapping and unique as compared to the expression domains of Lrig1 and the third family member, Lrig3. In adult human tissues, the most prominent LRIG2 mRNA expression was found in skin, uterus and ovary. To study the developmental and physiological role of LRIG2, Lrig2 knock-out mice were generated. The knock-out mice were born at Mendelian frequencies without any apparent morphological abnormalities. However, Lrig2 knock-out mice showed reduced body weight between 5 days and 12-15 weeks of age, increased mortality, and impaired reproductive capacity. To study the role of LRIG2 as a prognostic factor in oligodendroglioma, LRIG2 expression was analyzed in 65 human oligodendrogliomas by immunohistochemistry. Cytoplasmic LRIG2 expression was an independent prognostic factor associated with poor oligodendroglioma patient survival. The possible functional role of LRIG2 in oligodendroglioma biology was further investigated using the RCAS/tv-a mouse model. Tumors resembling human oligodendroglioma were induced by intracranial injection of PDGFB carrying RCAS retroviruses into newborn Ntv-a mice. Lrig2 wild-type animals developed tumors at a higher frequency and of higher malignancy than the Lrig2 knock-out mice. This result supports the notion that LRIG2 promotes PDGF-induced oligodendroglioma genesis. A possible molecular mechanism was revealed as LRIG2 overexpression increased PDGFRa levels in transfected cells. In summary, we identified a new gene named LRIG2, showed that it is expressed in a variety of tissues during development and in adulthood, knocked it out and found that it was required for proper animal growth, health, and reproduction. We also found that Lrig2 expression promoted PDGF-induced oligodendroglioma genesis and was associated with poor oligodendroglioma patient survival, possibly via a PDGFRa stabilizing function.
|
|
| 7. |
- Nord, Helena, et al.
(författare)
-
Novel amplifications in pediatric medulloblastoma identified by genome-wide copy number profiling
- 2012
-
Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 107:1, s. 37-49
-
Tidskriftsartikel (refereegranskat)abstract
- Medulloblastoma (MB) is a WHO grade IV, invasive embryonal CNS tumor that mainly affects children. The aggressiveness and response to therapy can vary considerably between cases, and despite treatment, ~30% of patients die within 2 years from diagnosis. Furthermore, the majority of survivors suffer long-term side-effects due to severe management modalities. Several distinct morphological features have been associated with differences in biological behavior, but improved molecular-based criteria that better reflect the underlying tumor biology are in great demand. In this study, we profiled a series of 25 MB with a 32K BAC array covering 99% of the current assembly of the human genome for the identification of genetic copy number alterations possibly important in MB. Previously known aberrations as well as several novel focally amplified loci could be identified. As expected, the most frequently observed alteration was the combination of 17p loss and 17q gain, which was detected in both high- and standard-risk patients. We also defined minimal overlapping regions of aberrations, including 16 regions of gain and 18 regions of loss in various chromosomes. A few noteworthy narrow amplified loci were identified on autosomes 1 (38.89-41.97 and 84.89-90.76 Mb), 3 (27.64-28.20 and 35.80-43.50 Mb), and 8 (119.66-139.79 Mb), aberrations that were verified with an alternative platform (Illumina 610Q chips). Gene expression levels were also established for these samples using Affymetrix U133Plus2.0 arrays. Several interesting genes encompassed within the amplified regions and presenting with transcript upregulation were identified. These data contribute to the characterization of this malignant childhood brain tumor and confirm its genetic heterogeneity.
|
|
| 8. |
- Paulsson, Janna, et al.
(författare)
-
Prognostic but not predictive role of platelet-derived growth factor receptors in patients with recurrent glioblastoma
- 2011
-
Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 128:8, s. 1981-1988
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor receptor (PDGFR) signaling has been implicated in the pathogenesis of glioblastomas and represents a target for the tyrosine kinase inhibitor imatinib. To examine the prognostic or predictive role of PDGFRs in recurrent glioblastomas, expression was examined in tumor samples of 101 patients of CSTI571BDE40, a randomized trial comparing hydroxyurea monotherapy and a combination of hydroxyurea and imatinib. Furthermore, PDGFRa phosphorylation was investigated using in situ proximity ligation assay. PDGFRa protein was expressed in 33% of tumors and was associated with male sex, young age, presence of R132H mutated isocitrate dehydrogenase 1 protein and short median survival (142 vs. 187 days, p = 0.028). Tumor PDGFRa phosphorylation was also associated with short survival (p = 0.030). The subset of patients with PDGFRa positive glioblastoma did not have longer survival on treatment with hydroxyurea and imatinib compared with hydroxyurea monotherapy. In conclusion, both PDGFRa protein expression and phosphorylation status had a prognostic role in recurrent glioblastomas but did not define a group that showed benefit from the combination therapy consisting of hydroxyurea and imatinib.
|
|
| 9. |
- Peng, Zhuochun, et al.
(författare)
-
Operator Dependent Choice of Prostate Cancer Biopsy Has Limited Impact on a Gene Signature Analysis for the Highly Expressed Genes IGFBP3 and F3 in Prostate Cancer Epithelial Cells
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:10, s. e109610-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Predicting the prognosis of prostate cancer disease through gene expression analysis is receiving increasing interest. In many cases, such analyses are based on formalin-fixed, paraffin embedded (FFPE) core needle biopsy material on which Gleason grading for diagnosis has been conducted. Since each patient typically has multiple biopsy samples, and since Gleason grading is an operator dependent procedure known to be difficult, the impact of the operator's choice of biopsy was evaluated. Methods: Multiple biopsy samples from 43 patients were evaluated using a previously reported gene signature of IGFBP3, F3 and VGLL3 with potential prognostic value in estimating overall survival at diagnosis of prostate cancer. A four multiplex one-step qRT-PCR test kit, designed and optimized for measuring the signature in FFPE core needle biopsy samples was used. Concordance of gene expression levels between primary and secondary Gleason tumor patterns, as well as benign tissue specimens, was analyzed. Results: The gene expression levels of IGFBP3 and F3 in prostate cancer epithelial cell-containing tissue representing the primary and secondary Gleason patterns were high and consistent, while the low expressed VGLL3 showed more variation in its expression levels. Conclusion: The assessment of IGFBP3 and F3 gene expression levels in prostate cancer tissue is independent of Gleason patterns, meaning that the impact of operator's choice of biopsy is low.
|
|
| 10. |
- Pfeifer, Susan, et al.
(författare)
-
Swedish Biobank for Childhood Tumors
- 2014
-
Ingår i: Neuro-Oncology. - 1522-8517 .- 1523-5866. ; 16, s. 141-141
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
