| 1. |
- Eriksson, Anna, 1977-, et al.
(författare)
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AKN-028 induces cell cycle arrest, downregulation of Myc associated genes and a dose dependent reduction of kinase activity in acute myeloid leukemia
- 2014
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Ingår i: Biochemical Pharmacology. - : Elsevier. - 0006-2952 .- 1356-1839. ; 87:2, s. 284-291
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Tidskriftsartikel (refereegranskat)abstract
- AKN-028 is a novel tyrosine kinase inhibitor with preclinical activity in acute myeloid leukemia (AML), presently undergoing investigation in a phase I/II study. It is a potent inhibitor of the FMS-like kinase 3 (FLT3) but shows in vitro activity in a wide range of AML samples. In the present study, we have characterized the effects of AKN-028 on AML cells in more detail. AKN-028 induced a dose-dependent G(0)/arrest in AML cell line MV4-11. Treatment with AKN-028 caused significantly altered gene expression in all AML cell types tested (430 downregulated, 280 upregulated transcripts). Subsequent gene set enrichment analysis revealed enrichment of genes associated with the proto-oncogene and cell cycle regulator c-Myc among the downregulated genes in both AKN-028 and midostaurin treated cells. Kinase activity profiling in AML cell lines and primary AML samples showed that tyrosine kinase activity, but not serine/threonine kinase activity, was inhibited by AKN-028 in a dose dependent manner in all samples tested, reaching approximately the same level of kinase activity. Cells sensitive to AKN-028 showed a higher overall tyrosine kinase activity than more resistant ones, whereas serine/threonine kinase activity was similar for all primary AML samples. In summary, AKN-028 induces cell cycle arrest in AML cells, downregulates Myc-associated genes and affect several signaling pathways. AML cells with high global tyrosine kinase activity seem to be more sensitive to the cytotoxic effect of AKN-028 in vitro.
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| 2. |
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| 3. |
- Fryknäs, Mårten, et al.
(författare)
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STAT1 signaling is associated with acquired crossresistance to doxorubicin and radiation in myeloma cell lines
- 2007
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 120:1, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- The myeloma cell line RPMI 8226/S and its doxorubicin resistant subline 8226/Dox40 were used as models to explore the potential importance of the STAT1 signaling pathway in drug and radiation resistance. The 40-fold doxorubicin resistant subline 8226/Dox40 was found to be crossresistant to single doses of 4 and 8 Gy of radiation. A genome-wide mRNA expression study comparing the 8226/Dox40 cell line to its parental line was performed to identify the underlying molecular mechanisms. Seventeen of the top 50 overexpressed genes have previously been implicated in the STAT1 signaling pathway. STAT1 was over expressed both at the mRNA and protein level. Moreover, analyses of nuclear extracts showed higher abundance of phosphorylated STAT1 (Tyr 701) in the resistant subline. Preexposure of the crossresistant cells to the STAT1 inhibiting drug fludarabine reduced expression of overexpressed genes and enhanced the effects of both doxorubicin and radiation. These results show that resistance to doxorubicin and radiation is associated with increased STAT1 signaling and can be modulated by fludarabine. The data support further development of therapies combining fludarabine and radiation.
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| 4. |
- Gustafsson, Mats G., et al.
(författare)
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Improving Bayesian credibility intervals for classifier error rates using maximum entropy empirical priors
- 2010
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Ingår i: Artificial Intelligence in Medicine. - : Elsevier BV. - 0933-3657 .- 1873-2860. ; 49:2, s. 93-104
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Tidskriftsartikel (refereegranskat)abstract
- Objective:Successful use of classifiers that learn to make decisions from a set of patient examples require robust methods for performance estimation. Recently many promising approaches for determination of an upper bound for the error rate of a single classifier have been reported but the Bayesian credibility interval (Cl) obtained from a conventional holdout test still delivers one of the tightest bounds. The conventional Bayesian CI becomes unacceptably large in real world applications where the test set sizes are less than a few hundred. The source of this problem is that fact that the Cl is determined exclusively by the result on the test examples. In other words, there is no information at all provided by the uniform prior density distribution employed which reflects complete lack of prior knowledge about the unknown error rate. Therefore, the aim of the study reported here was to study a maximum entropy (ME) based approach to improved prior knowledge and Bayesian CIs, demonstrating its relevance for biomedical research and clinical practice.Method and material:It is demonstrated how a refined non-uniform prior density distribution can be obtained by means of the ME principle using empirical results from a few designs and tests using non-overlapping sets of examples.Results:Experimental results show that ME based priors improve the CIs when employed to four quite different simulated and two real world data sets.Conclusions:An empirically derived ME prior seems promising for improving the Bayesian Cl for the unknown error rate of a designed classifier.
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| 5. |
- Hassan, Saadia, et al.
(författare)
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Gene expression signature-based chemcial genomics and activity pattern in a panel of tumour cell lines propose linalyl acetate as a protein kinase/NF-κB inhibitor
- 2008
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Ingår i: Gene Therapy and Molecular Biology. - 1529-9120. ; 12:B, s. 359-370
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Tidskriftsartikel (refereegranskat)abstract
- The essential oil of Lebanese sage, Salvia libanotica, was reported to have anti-tumour activity; however, the mechanism of action has not been identified yet. In this study, 14- cancer cell lines including drug-sensitive and resistant lung, leukaemia, and colon, as well as primary human tumours of chronic lymphocytic leukaemia (CLL) and primary normal mononuclear cells (PBMCs) were used to characterize the anti-tumour activity and mechanism of action of linalyl acetate, a component of the Lebanese sage essential oil. Drug activity and gene expression data sets were utilized to identify drugs with similar activity patterns and genes involved in drug sensitivity/resistance. In addition, the Connectivity Map, a gene expression signature-based screening approach, assisted in predicting further the molecular action of linalyl acetate. Small cell lung carcinoma and colorectal cancer cell lines were the most sensitive to the drug and greater tumour selectivity was observed against chronic lymphocytic leukaemia cells compared to normal mononuclear cells. Only limited effect of some of the classical mechanisms of multi-drug resistance on the activity of Linalyl acetate was noted which makes it potentially interesting for drug-resistant patients. There was high similarity between the activity-pattern/gene expression profile of linalyl acetate and that of protein kinase/NF-kappa B inhibitors. Validating this, linalyl acetate was found to strongly inhibit Janus kinase, JAK3, and p38 alpha kinases in a cell-free assay as well as the NF-kappa B translocation in a dose-dependent manner. Taken together, our results show that the NF-kappa B inhibitor, linalyl acetate, may represent a new therapeutic compound in the management of inflammation and cancer.
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