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L C Andersson

Publications and source records attributed to L C Andersson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Expression of cyclin A in soft tissue sarcomas correlates with tumor aggressiveness.

Cyclins and cyclin-dependent kinases regulate the cell cycle. Cyclin A has a dual role in cell proliferation. It is essential in the S phase for DNA replication, and it is also involved in G2-M-phase transition, signifying actively dividing cells. The expression of cyclin A was determined by immunohistochemistry in paraffin sections of 126 soft tissue sarcomas. The median cyclin A score was 10.8% (range, 1-54%). Cyclin A expression correlated with the S-phase fraction, Ki-67 score, G2-M phase, and grade. It did not correlate with the size of the tumor. A high cyclin A score predicted a poor metastasis-free survival (P < 0.01) and a poor disease-specific overall survival (P = 0.01). We concluded that the expression of cyclin A is a powerful prognostic factor in soft tissue sarcoma. Moreover, the cyclin A score determines the fraction of tumor cells in the S phase and the G2 phase, which are the most sensitive cell cycle phases for current modalities of cancer treatment.

Adolescent↗
PubMed1999

Translocation of ornithine decarboxylase to the surface membrane during cell activation and transformation.

Ornithine decarboxylase (ODC) is highly up-regulated in proliferating and transforming cells. Here we show that upon induction, an initial cytosolic increase of ODC is followed by translocation of a fraction of the enzyme to the surface membrane. ODC membrane translocation is mediated by a p47(phox) membrane-targeting motif-related sequence, as indicated by reduced ODC activity in the membrane fraction of cells treated with a competing, ODC-derived (amino acids 165-172) peptide, RLSVKFGA, which is homologous to the p47(phox) membrane-targeting sequence. p47(phox) membrane translocation is known to be dependent on the phosphorylation of the targeting motif. Analogously, overexpressed ODC.S167A, a mutant ODC lacking the putative phosphorylation site Ser67, is unable to move to the surface membrane. Cells blocked with the RLSVKFGA peptide showed defective transformation, indicating that the motif-mediated translocation of ODC is prerequisite to its biological function. Constitutive targeting of ODC to the membrane using a plasmid encoding the chimeric protein, wild-type ODC with C-terminal linkage to the farnesylation motif of K-ras, caused impaired cytokinesis with an accumulation of polykaryotic cells. Impaired cytokinesis confirms that ODC is involved in mitotic cytoskeletal rearrangement events and pinpoints the importance of relevant membrane targeting to its physiological function.

3T3 Cells↗
PubMed1999

Comparison of the Ki-67 score and S-phase fraction as prognostic variables in soft-tissue sarcoma.

Immunohistochemically determined Ki-67 scores and flow cytometrically determined S-phase fractions were successfully evaluated from the primary tumours of 123 patients with soft-tissue sarcoma. All patients had either limb or superficial trunk tumours. Ki-67 score correlated strongly with ploidy, S-phase fraction and grade. Ki-67 did not correlate with the size of the primary tumour. When analysed as a continuous variable, Ki-67 was a stronger predictor of both metastasis-free survival and disease-specific overall survival (P = 0.003 and 0.04 respectively) than was the S-phase fraction (P = 0.06 and 0.07 respectively). We tested the relevance of different cut-point values by dividing the whole material into two parts at every 10% (e.g. 10% of patients vs. the remaining 90%, 20% vs. 80%, etc.). We counted the relative risk and confidence interval at all these cut-off points. Ki-67 had good prognostic discriminating power irrespective of the cut-point value, but S-phase fraction lost its prognostic power at higher cut-point values. In conclusion, we found that Ki-67 is a useful prognostic tool in the treatment of soft-tissue sarcoma patients irrespective of the cut-point value. S-phase fraction can be used at lower cut-point values.

Adolescent↗
PubMed1999

A high proliferation rate measured by cyclin A predicts a favourable chemotherapy response in soft tissue sarcoma patients.

A small but not insignificant number of patients experience a prolonged survival after treatment of metastatic soft tissue sarcoma. This must be weighed against the majority of the patients who benefit little from the therapy, but nevertheless experience its side-effects. It would therefore be of utmost importance to be able to screen for those patients who respond to the treatment. Since proliferating cells are more sensitive to chemotherapy than non-proliferative cells, we measured the proliferation rate of the primary tumour of 55 soft tissue sarcoma patients with locally advanced or metastatic disease by determining the flow cytometric S phase fraction and immunohistochemical Ki-67 and cyclin A scores. S phase fraction or Ki-67 score did not predict chemotherapy response or progression-free survival. A high cyclin A score, however, correlated with a better chemotherapy response (P = 0.02) and longer progression-free survival time (P = 0.04). Our results suggest that a high cyclin A score predicts chemotherapy sensitivity.

Adolescent↗
PubMed1999

Regulation of neural differentiation by normal and mutant (G654A, amyloidogenic) gelsolin.

Gelsolin belongs to a family of proteins that modulate the structural dynamics of cytoskeletal actin. Gelsolin activity is required for the redistribution of actin occurring during membrane ruffling, cell crawling, and platelet activation. A point mutation (G654A) in the gelsolin gene causes a dominantly inherited systemic amyloidosis called familial amyloidosis of the Finnish type (FAF). This disease is characterized by a cranial neuropathy that cannot be explained solely by amyloid deposits. To address the question of whether gelsolin has a specific role in neural cell development, we transfected cDNA for wild type and G654A point-mutated gelsolin into a neural cell line, Paju, which can be induced to differentiate by treatment with phorbol 12-myristate 13-acetate. Overexpressed wild type gelsolin inhibited neural differentiation whereas mutated gelsolin did not, indicating that appropriate gelsolin activity is essential for neural sprouting. The G654A mutant gelsolin induced stabilization of F-actin and reduced the plasticity of neural development. This provides a novel etiopathogenetic mechanism for the neuronal dysfunction in FAF.

Adolescent↗
PubMed1999

Accumulation of macrophages in the CSF of schizophrenic patients during acute psychotic episodes.

OBJECTIVE: There have been numerous reports of organic or structural abnormalities in the central nervous system (CNS) of patients with schizophrenia. Given that pathological conditions in the CNS are frequently reflected in the cell profiles of CSF, the authors compared the cytology of CSF from schizophrenic patients with that from a reference population in order to find out trails of elementary pathogenetic events in this serious psychiatric disease. METHOD: CSF samples from 35 patients with acute schizophrenia and 46 comparison subjects were prepared by Millipore filtration. The total and differential counts of CSF mononuclear cells were performed by light microscopy. RESULTS: At the beginning of treatment, the proportion of mononuclear phagocytes/macrophages in the patients' CSF was significantly higher than that in the comparison subjects. During treatment with conventional neuroleptic medication, the cytology returned to normal in several patients. CONCLUSIONS: The high proportion of macrophages in schizophrenia without a significantly higher total cell count may reflect neurodevelopmental disorder, a neurodegenerative process, or subtle CNS immunoactivation with mobilization of microglia.

Acute Disease↗
PubMed1998

2-Methoxyestradiol-induced phosphorylation of Bcl-2: uncoupling from JNK/SAPK activation.

The natural estrogen metabolite 2-methoxyestradiol (2ME) is anti-angiogenic in vivo and a strong growth inhibitor in vitro. The growth inhibition is due to mitotic arrest and apoptosis. These effects are reminiscent of those induced by taxol, and appear to be mediated by inhibition of microtubule dynamics. Here we have studied the cellular response to 2ME in regard to potential mediators of the observed cellular changes. 2ME treatment increases the insoluble polymerized fraction of cellular tubulin similar to taxol, and in contrast to the microtubule depolymerizing drugs such as colcemid and vincristine. This stabilization following 2ME treatment is accompanied by phosphorylation and inactivation of Bcl-2 increasing gradually from 2-24 hours. To study the pathway leading to Bcl-2 phosphorylation we analyzed Raf-1 and JNK/SAPK kinases, both of which have been reported to be involved in Bcl-2 inactivation. Our results indicate that Raf-1 is phosphorylated in response to 2ME, but this occurs later than Bcl-2 phosphorylation suggesting that Raf-1 is not directly phosphorylating Bcl-2. JNK/SAPK was activated rapidly after 2ME treatment. However, this activation was transient and returned to undetectable levels by 2 hours of treatment, demonstrating that JNK/SAPK is not directly phosphorylating Bcl-2. Taken together with previous results indicating that overexpression of JNK/SAPK leads to Bcl-2 phosphorylation, our results would support a model where JNK/SAPK is indirectly phosphorylating Bcl-2.

2-Methoxyestradiol↗
PubMed1998

Epithelial expression of glycodelin in biphasic synovial sarcomas.

Glycodelin is a 28 kDa glycoprotein of the lipocalin family that was previously considered to be specific for the reproductive tract. Glycodelin is found in the secretory glandular epithelium of endometrium and in seminal vesicles. Given the cyclic differentiation of normal endometrial epithelium, we studied by immunohistochemistry a possible expression of glycodelin in other tissues displaying stroma-to-epithelium maturation. We report here that 11/11 biphasic synovial sarcomas expressed glycodelin in the cells exhibiting epithelial or glandular differentiation while the sarcomatous spindle cells remained negative. Glycodelin was also found in secreted material in the lumina of the gland-like structures. In only 1 of the 7 monophasic synovial sarcomas studied, focal glycodelin reactivity was seen in some flattened spindle cells. The expression of glycodelin in biphasic synovial sarcoma tissue was further verified by the demonstration of glycodelin mRNA by reverse transcriptase-polymerase chain reaction. Considering the monoclonal origin of synovial sarcomas, our findings raise the intriguing possibility that activation of expression of the glycodelin gene is involved in the molecular regulation of mesenchyme-to-epithelium differentiation.

Epithelium↗
PubMed1998

Cytogenetic chromosomal preparations using 2-methoxyestradiol.

The antimitotic drug 2-methoxyestradiol is an end metabolite of catechol estrogens. In vivo, it arrests cells in mitosis by interfering with the dynamics of the mitotic spindle without disrupting tubulin formation. It has a mitotic index similar to that of Colcemid in different cell lines. Here we report that 2-methoxyestradiol can be used for making cytogenetic preparations of comparable quality to that of colcemid. In addition, 2-methoxyestradiol is devoid of the toxicity associated with Colcemid, which may make 2-methoxyestradiol useful in slowly growing samples often found in primary solid tumor cultures where a sufficient number of mitotic cells is difficult to obtain.

2-Methoxyestradiol↗
PubMed1998

Up-regulated expression of decay-accelerating factor (CD55) confers increased complement resistance to sprouting neural cells.

We studied gene expression in relation to induced neural differentiation in a human neural crest-derived cell line, Paju. Messenger RNA isolated before and after treatment with phorbol 12-myristate 13-acetate was analyzed by differential display reverse transcription PCR. A strongly up-regulated expression of decay-accelerating factor (DAF, CD55) was found to parallel the induced neural sprouting while the expression of two other complement regulatory proteins (CD59/protectin, CD46/membrane cofactor protein) remained unaltered during neural differentiation. The increased membrane expression of DAF, which was also seen on neural processes and growth cones, conferred elevated resistance to complement-mediated lysis. Our findings suggest that in sprouting neurons DAF expression is up-regulated to provide additional complement resistance to pathfinding axons/dendrites invading new environment. It is also suggested that membrane expression of DAF may constitute a marker of growing and regenerating neurons.

CD55 Antigens↗
PubMed1998

High expression of stanniocalcin in differentiated brain neurons.

Stanniocalcin (STC) is a glycoprotein hormone first found in fish, in which it regulates calcium homeostasis and protects against hypercalcemia. Human and mouse stc cDNA were recently cloned. We found a dramatically upregulated expression of STC during induced neural differentiation in a human neural crest-derived cell line, Paju. Immunohistochemical staining of sections from human and adult mouse brain revealed abundant presence of STC in the neurons with no activity in the glial cells. STC expression was not seen in immature brain neurons of fetal or newborn mice. Given that STC has been found to regulate calcium/phosphate metabolism in some mammalian epithelia, we suggest that STC may act as a regulator of calcium homeostasis in terminally differentiated brain neurons.

Animals↗
PubMed1998

Different patterns of DNA copy number changes in gastrointestinal stromal tumors, leiomyomas, and schwannomas.

It is not uniformly agreed whether gastrointestinal stromal tumors (GISTs) are phenotypical variants of leiomyomas (cellular leiomyomas) or whether they represent a separate, genotypically definable entity. In an attempt to solve this question, we examined immunohistochemically defined leiomyomas from the esophagus and uterus, gastric schwannomas, and benign gastrointestinal stromal tumors (GIST) by comparative genomic hybridization (CGH). All 14 leiomyomas (nine esophageal, five uterine) were actin- and desmin-positive but negative for CD34 and S100-protein. Changes in DNA copy numbers were seen only in three esophageal leiomyomas. Gains were observed in chromosomes 3, 4, 5, 8, and 17, whereas losses were seen in 16p. All schwannomas were positive for S100-protein and negative for actin, desmin, and CD34. In schwannomas, the only change by CGH was a gain in 11q in one case. The benign GISTs, all from the stomach, were positive for CD34 but negative for desmin and S100-protein; two cases were positive for actin. The CGH findings in the GISTs differed markedly from those in leiomyomas and schwannomas. Ten of the 13 cases (77%) showed DNA copy number losses in 14q, and additional or other losses were found in eight cases, most often in chromosome 22 (seven cases), 15 (three cases), and 1p (two cases). Furthermore, two of the GISTs showed gains in 5q. These results indicate that phenotypically undifferentiated GISTs are also genetically different from leiomyomas and schwannomas and support their classification apart from leiomyomas.

Actins↗
PubMed1998

Signalling initiated with CD4-TCR or TCR-TCR interactions: comparison of tyrosine phosphorylation patterns and CD45 effects.

Antigen-triggered response in T cells is mediated by the T cell receptor (TCR)/CD3-complex. This signalling, however, is modulated by a number of other surface molecules. Among the most important of these is the CD4/CD8 molecule which associates with the TCR/CD3-complex and binds to the MHC complex. The molecular mechanisms involved in interactions between TCR-TCR and TCR-CD4 are not fully understood. We have earlier described an experimental model that allows us to dissect signals involving CD4-TCR interactions and those involving TCR-TCR interactions using a mouse CD4-CD8- T cell hybridoma cell-line transfected either with the TCR from a mouse T-helper 2 cell-line (D10) alone or with both the TCR and the CD4 molecule. To further characterize these two different modes of signalling in T lymphocytes we have studied the tyrosine phosphorylation patterns resulting from these interactions. In addition, we have studied the modulatory effect of the CD45 molecule on these interactions. In contrast to some earlier reports, we found that both the patterns of induced tyrosine phosphorylation and the effects of CD45 modulation were essentially similar in the CD4-TCR and the TCR-TCR signal transduction cascades. The results are consistent with a purely synergistically amplifying function for CD4 on the TCR-mediated signalling.

Animals↗
PubMed1998

p72syk protein tyrosine kinase: an early transducer of sIgG-triggered apoptotic signalling in human follicular lymphoma cells.

Cross-linking of B cell antigen receptor (sIg) elicits different biological responses, including cell activation, proliferation, differentiation, anergy and cell death depending on the maturational stage of the cell. We established the tumor cell lines HF-1.3.4 and HF-4-9 from two patients with follicular lymphoma. Both cell lines carry the characteristic t(14;18) chromosomal translocation and display constitutively overexpressed Bcl-2. HF-1.3.4 represents a mature B cell with sIgG and several somatic hypermutations in its Ig genes, while HF-4-9 is a less mature B cell, expressing sIgM and only a few mutations in its Ig genes. Cross-linking of sIg with antibodies leads to apoptosis in HF-1.3.4 cells but not in HF-4-9 cells. Triggering of sIg induced, within seconds, identical tyrosine phosphorylation of p53/56lyn protein tyrosine kinase (PTK) and p55blk PTK in both of the cell lines; however, a prominent tyrosine phosphorylation and activation of p72syk PTK only in HF-1.3.4 cells. We conclude that p72syk PTK is of importance in relaying apoptotic signalling upon sIg cross-linking in the HF-1.3.4 cell line. Given the mature phenotype of the HF-1.3.4 cell line it serves as a model for the late negative selection during B cell ontogeny. Moreover, our results question the current concept that a constitutive overexpression of BcI-2 confers resistance to sIg ligation-induced apoptosis in lymphoma cells.

Apoptosis↗
PubMed1998

Association between HLA-A1 allele and schizophrenia gene(s) in patients refractory to conventional neuroleptics but responsive to clozapine medication.

We report an association between HLA-A1 allele and a subgroup of schizophrenic patients refractory to conventional neuroleptic treatment but responsive to clozapine. The frequency of HLA-A1 was 58% among the schizophrenic patients not responding to conventional treatment but responsive to clozapine but only 10.5% among the patients responding to conventional neuroleptics. The HLA-A1 occurs in 20% of the random Finnish population. Our results indicate that HLA-A1 defines a subgroup of schizophrenic patients with a selective response to neuroleptics.

Adult↗
PubMed1998

DNA copy number changes in gastrointestinal stromal tumors--a distinct genetic entity.

It is not universally agreed whether gastrointestinal stromal tumors (GISTs) are phenotypical variants of leiomyomas (LM) and leiomyosarcomas (LMS), or whether they belong to a separate phenotypic entity with a different genetic background. This is a summary of our published results from comparative genomic hybridization studies performed in order to solve this question. We studied DNA copy number changes in 32 immunohistochemically well-defined GISTs (13 malignant, 3 borderline, and 16 benign tumors), 14 LM, and 29 LMS. In GISTs, a consistent finding was the loss of DNA copy numbers in chromosome 14q. This loss was detected in 75% of the benign tumors, in 62% of the malignant tumors, and in two out of the three borderline tumors with the minimal overlapping region located to 14q22. The loss was not seen in LM and in LMS it was rare (4 cases, 13%). Only three LM cases showed DNA copy number changes: gains in chromosome 3, 4, 5, 8, and 17. A total of 137 losses and 204 gains were detected in LMS. The most frequent losses were detected in 10q (20 cases, 69%) and 13q (17 cases, 59%). The most frequent gains were detected in 17p (16 cases, 55%). The most frequent high-level amplifications were detected in 17p (7 cases, 24%) and 8q (6 cases, 21%). Our results indicate that DNA copy number losses in 14q are an early change during the oncogenesis of GISTs. Moreover, the pattern of the demonstrated DNA copy number changes suggests that GISTs are a phenotypic and genetic entity separate from leiomyomas and leiomyosarcomas.

Chromosomes, Human, Pair 10↗
PubMed1997

Detection of colorectal neoplasia with peanut-agglutinin (PNA)-reactive carbohydrate structures in rectal mucus.

In contrast to normal colorectal mucosa, peanut-agglutinin-(PNA)-reactive glycoconjugates are commonly expressed in most colorectal carcinomas and in some pre-malignant conditions such as adenomas and ulcerative colitis. Since enzymatically detectable galactose-beta1-3-N-acetyl-galactosamine residues are found in rectal mucus obtained from patients with carcinoma of the large bowel, it was investigated here whether PNA-reactive carbohydrate structures in rectal mucus can be exploited in the detection of colorectal neoplasia. Samples of rectal mucus obtained from 261 randomly selected patients with colorectal symptoms were applied on nitrocellulose filters. The presence of PNA-reactive glycoconjugates in mucus samples was determined by a peroxidase-conjugated PNA-overlay procedure. The results were correlated to findings from total colonoscopy/surgery and histopathology. PNA-reactive carbohydrate structures were detected in 76% of patients with carcinoma (p < 0.005), in 62% of patients with adenoma (p < 0.005), in 69% of patients with inflammatory bowel disease (p < 0.005), and in 38% of patients with hyperplastic polyps (NS), in contrast to 21% of the control subjects with macroscopically normal colorectal mucosa. These results show that PNA-reactive carbohydrate alterations in rectal mucus correlates with neoplastic and hyperproliferative conditions of the colorectal mucosa. The specificity of the PNA test for colorectal neoplasia was 76%. Therefore the use of more discriminate carbohydrate probes are needed for the pre-symptomatic detection of colorectal neoplasia.

Adenoma↗