| 41. |
- Chylicki, Kristina, et al.
(författare)
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Characterization of the molecular mechanisms for p53-mediated differentiation
- 2000
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Ingår i: Cell Growth and Differentiation. - 1044-9523. ; 11:11, s. 561-571
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Tidskriftsartikel (refereegranskat)abstract
- The p53 tumor suppressor protein can induce both apoptosis and cell cycle arrest. Moreover, we and others have shown previously that p53 is a potent mediator of differentiation. For example, expression of ptsp53, a temperature-inducible form of p53, induces differentiation of leukemic monoblastic U-937 cells. The functions of p53 have for long been believed to be dependent on the transactivating capacity of p53. However, recent data show that both p53-induced cell cycle arrest and apoptosis can be induced independently of p53-mediated transcriptional activation, indicating alternative pathways for p53-induced apoptosis and cell cycle arrest. The bcl-2 proto-oncogene contributes to the development of certain malignancies, probably by inhibition of apoptosis. Interestingly, Bcl-2 has been shown to inhibit p53-mediated apoptosis as well as p53-mediated transcriptional activation. Asking whether Bcl-2 would interfere with the p53-mediated differentiation of U-937 cells, we stably transfected bcl-2 to U-937 cells inducibly expressing p53. Although the established Bcl-2-expressing clones were resistant to p53-mediated apoptosis, we did not observe any interference of Bcl-2 with the p53-mediated differentiation, suggesting separable pathways for p53 in mediating apoptosis and differentiation of U-937 cells. Neither did expression of Bcl-2 interfere with p53-induced expression of endogenous p21, suggesting that p53-induced differentiation might be dependent on the transcriptional activity of p53. To further investigate whether the p53-mediated differentiation of U-937 cells depends on the transcriptional activity of p53, we overexpressed transactivation-deficient p53, a transcriptionally inactive p53 mutant in these cells. However, in contrast to the effects of wild-type p53, expression of trans-activation-deficient p53 did neither induce signs of apoptosis nor of differentiation in U-937 cells. Our results indicate that the transcriptional activity of p53 is essential both for p53-mediated apoptosis and differentiation of U-937 cells.
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| 42. |
- Dahlén, A, et al.
(författare)
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Analysis of the distribution and frequency of trisomy 7 in vivo in synovia from patients with osteoarthritis and pigmented villonodular synovitis
- 2001
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Ingår i: Cancer Genetics and Cytogenetics. - 0165-4608. ; 131:1, s. 19-24
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Tidskriftsartikel (refereegranskat)abstract
- Osteoarthritis (OA) and pigmented villonodular synovitis (PVNS) are disorders associated with trisomy 7. The aim of the present study was to determine the frequency and distribution of the cells with +7 in vivo by analyzing sections of paraffin-embedded synovia from patients affected by OA, PVNS, other forms of synovitis [hemorragic synovitis (HS) and chronic synovitis (CS)], and from individuals without joint disease. Fluorescence in situ hybridization (FISH), using a centromeric probe for chromosome 7, showed that the mean frequency of trisomic nuclei in 5-microm sections was highest in PVNS (9.0%), followed by CS (5.9%), OA (5.6%), and HS (4.6%), whereas trisomic nuclei were rare (0.7%) in normal tissue. When 8-microm sections were studied, the frequencies of trisomic cells in OA and control synovia increased to 6.7% and 1.5%, respectively. Trisomic nuclei were found in all cases, including those for which cytogenetic analysis of short-term cultures had not disclosed any trisomic cells. Overall, the trisomic cells were scattered within the tissue. However, small clusters of cells with +7 were found in three cases. By hematoxylin-eosin staining of the slides used for FISH analysis it could be shown that the clustered trisomic cells were proliferating synoviocytes within villous extensions of the synovial membrane.
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| 43. |
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| 44. |
- Elomaa, I, et al.
(författare)
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Five-year results in Ewing's sarcoma. The Scandinavian Sarcoma Group experience with the SSG IX protocol
- 2000
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Ingår i: European Journal of Cancer. - 1879-0852. ; 36:7, s. 875-880
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Tidskriftsartikel (refereegranskat)abstract
- The first Scandinavian protocol for Ewing's sarcoma, SSG IV, resulted in a local control rate of 74% and 5-year metastasis-free survival (MFS) of 43%. The second protocol, SSG IX, was started in order to improve upon these results. It featured four chemotherapy cycles, each consisting of two courses of VAI (vincristine, doxorubicin, ifosfamide) alternating with one course of PAI (cisplatin, doxorubicin, ifosfamide) at 3-weekly intervals. Total treatment time was 35 weeks. Local therapy was given at week 9. Inoperable or non-radically operated patients received hyperfractionated accelerated radiotherapy 1.5 Gy twice daily between chemotherapy courses to a total dose of 42-60 Gy, depending on surgical radicality and tumour localisation. 88 patients were included (58 male, 30 female, mean age 20 years; range 5-65 years). The tumour (73 M0 and 15 M1) was located centrally in 31 patients (35%), in the extremities in 34 (39%) and other sites in 23 (26%) of cases. The median size of tumour was 10 cm (range 2-23), soft tissue was invaded in 87%. Surgery was the local therapy for 60 (68%) patients: amputation in 8 and local excision in 52. The surgical margins were wide in 35 patients, marginal in 14 and intralesional in 3. Radiotherapy was given to 17 non-radically operated patients postoperatively and to 28 patients with inoperable tumours primarily. Histological responses were evaluated in 52 patients. 9 local recurrences were observed (10%). Distant metastases developed in 24 M0 patients (33%). The estimated 5-year MFS was 58% and overall survival (OS) 70% for M0 and 27% and 28% for M1 patients, respectively. Survival was favourable in patients with non-metastatic extremity tumours (90%) and tumours operated with wide margins (90%). Patients with a total necrosis after chemotherapy had a better OS than those with a partial or poor response (P=0.003). The toxicity (World Health Organisation) was acceptable (gastrointestinal G1-2; haematological G3-4). The SSG IX protocol gave better local control and survival rates than the SSG IV. Whether this is due to a higher therapeutic efficacy of the present protocol cannot be ascertained in this comparison with a historical control.
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| 45. |
- Falkenberg, Cecilia, et al.
(författare)
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Expression of a functional proteinase inhibitor capable of accepting xylose: bikunin
- 2001
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Ingår i: Archives of Biochemistry and Biophysics. - : Elsevier BV. - 0003-9861. ; 387:1, s. 99-106
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Tidskriftsartikel (refereegranskat)abstract
- Bikunin is a Kunitz-type proteinase inhibitor, which is cross-linked to heavy chains via a chondroitin sulfate chain, forming inter-alpha-inhibitor and related molecules. Rat bikunin was produced by baculovirus-infected insect cells. The protein could be purified with a total yield of 20 mg/liter medium. Unlike naturally occuring bikunin the recombinant protein had no galactosaminoglycan chain. Endoglycosidase digestion also suggested that the recombinant form lacked N-linked oligosaccharides. Bikunin is translated as a part of a precursor, alpha1-microglobulin/bikunin, but the functional significance of the cotranslation is unknown. Our results indicate that the proteinase inhibitory function of bikunin is not regulated by the alpha1-microglobulin-part of the alpha1-microglobulin/bikunin precursor since recombinant bikunin had the same trypsin inhibitory activity as the recombinant precursor. Both free bikunin and the precursor were also functional as a substrate in an in vitro xylosylation system. This demonstrates that the alpha1-microglobulin-part is not necessary for the first step of galactosaminoglycan assembly.
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| 46. |
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| 47. |
- Hallén, Magnus, et al.
(författare)
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Cytogenetic abnormalities in a hemangiopericytoma of the spleen.
- 2002
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Ingår i: Cancer Genetics and Cytogenetics. - 0165-4608. ; 136:1, s. 62-65
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Tidskriftsartikel (refereegranskat)abstract
- To date, only 16 cytogenetically abnormal hemangiopericytomas (HP) have been reported. Despite this low number, some characteristic karyotypic features have already emerged: most HP are near-diploid and breakpoints in 12q13, 12q24, and 19q13 seem to be common, with t(12;19)(q13;q13) being a recurrent translocation. Here, we report the first case of a probably benign splenic HP with chromosomal abnormalities. The abnormal karyotype was 47,XX,t(5;22;11)(q31;q11;q13),+10. None of these abnormalities have previously been reported in HP, suggesting that the karyotypic pattern of splenic HP may differ from soft tissue HP.
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| 48. |
- Hashemi, S H, et al.
(författare)
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111In-labelled octreotide binding by the somatostatin receptor subtype 2 in neuroendocrine tumours.
- 2003
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Ingår i: The British journal of surgery. - : Oxford University Press (OUP). - 0007-1323 .- 1365-2168. ; 90:5, s. 549-54
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the importance of somatostatin receptor subtype 2 (SSTR2) expression for 111In-labelled diethylenetriamine-pentaacetic acid (DTPA)-D-Phe1-octreotide binding and uptake of 111In in neuroendocrine tumours.
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| 49. |
- Jakobsen, A M, et al.
(författare)
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Differential expression of vesicular monoamine transporter (VMAT) 1 and 2 in gastrointestinal endocrine tumours.
- 2001
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Ingår i: The Journal of pathology. - : Wiley. - 0022-3417. ; 195:4, s. 463-72
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Tidskriftsartikel (refereegranskat)abstract
- Neuroendocrine tumours are characterized by their capacity to produce hormones, which are stored in vesicles and secretory granules. Demonstration of granule/vesicle proteins in tumours is taken as evidence of neuroendocrine differentiation. Vesicular monoamine transporters (VMAT1 and VMAT2) mediate the transport of amines into vesicles of neurons and endocrine cells. The expression of VMAT1 and VMAT2 and the usefulness of VMAT1 and VMAT2 in the histopathological diagnosis of gastrointestinal endocrine tumours have not been fully explored. This study therefore investigated the expression of VMAT1 and VMAT2 in 211 human gastrointestinal tumours by immunocytochemistry and western blotting. VMAT1 and/or VMAT2 were demonstrated in the majority of amine-producing endocrine tumours of gastric, ileal, and appendiceal origin. Serotonin-producing endocrine tumours (ileal and appendiceal carcinoids) expressed predominantly VMAT1, while histamine-producing endocrine tumours (gastric carcinoids) expressed VMAT2 almost exclusively. In peptide-producing endocrine tumours such as rectal carcinoids and endocrine pancreatic tumours, only a small number of immunopositive tumour cells were observed. No labelling was found in non-endocrine tumours, including gastric, colorectal and pancreatic adenocarcinomas and gastrointestinal stromal tumours. In conclusion, VMAT1 and VMAT2 are differentially expressed by gastrointestinal endocrine tumours, with a pattern specific for each tumour type, reflecting their neuroendocrine differentiation and origin. VMAT1 and VMAT2 may therefore become valuable markers in the classification of neuroendocrine tumours and may also indicate patients suitable for radioisotope treatment operating via these transporter systems.
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| 50. |
- Johansson, M., et al.
(författare)
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Interleukin-2 and histamine in combination inhibit tumour growth and angiogenesis in malignant glioma
- 2000
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Ingår i: British Journal of Cancer. - : Cancer Research Campaign. - 0007-0920 .- 1532-1827. ; 83:6, s. 826-832
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Tidskriftsartikel (refereegranskat)abstract
- Biotherapy including interleukin-2 (IL-2) treatment seems to be more effective outside the central nervous system when compared to the effects obtained when the same tumour is located intracerebrally. Recently published studies suggest that reduced activity of NK cells in tumour tissue can be increased by histamine. The present study was designed to determine whether IL-2 and histamine, alone or in combination, can induce anti-tumour effects in an orthotopic rat glioma model. One group of rats was treated with histamine alone (4 mg kg(-1)s.c. as daily injections from day 6 after intracranial tumour implantation), another group with IL-2 alone as a continuous subcutaneous infusion and a third group with both histamine and IL-2. The animals were sacrificed at day 24 after tumour implantation. IL-2 and histamine in combination significantly reduced tumour growth. The microvessel density was significantly reduced, an effect mainly affecting the small vessels. No obvious alteration in the pattern of VEGF mRNA expression was evident and no significant changes in apoptosis were observed. Neither IL-2 nor histamine alone caused any detectable effects on tumour growth. Histamine caused an early and pronounced decline in tumour blood flow compared to normal brain. The results indicate that the novel combination of IL-2 and histamine can be of value in reducing intracerebral tumour growth and, thus, it might be of interest to re-evaluate the therapeutic potential of biotherapy in malignant glioma.
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