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- Wickström, Malin, et al.
(författare)
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The alkylating prodrug J1 can be activated by aminopeptidase N, leading to a possible target directed release of melphalan
- 2010
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Ingår i: Biochemical Pharmacology. - : Elsevier BV. - 0006-2952 .- 1356-1839 .- 1873-2968. ; 79:9, s. 1281-1290
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Tidskriftsartikel (refereegranskat)abstract
- The alkylating prodrug of melphalan, J1 (melphalanyl-l-p-fluorophenylalanyl ethyl ester) is currently in early clinical trials. Preclinical studies have shown that J1-mediated cytotoxicity is dependent on hydrolytic activity of tumor cells. In this report we have analyzed potential peptidases and esterases of importance for release of free melphalan from J1. Exposure of tumor cell lines to J1 resulted in a significant increased level of free intracellular melphalan, at least tenfold at Cmax, compared to exposure to melphalan at the same molar concentration. This efficient intracellular delivery could be inhibited in both magnitude and in time by bestatin, a broad spectrum inhibitor of the aminopeptidases, including the metalloproteinase aminopeptidase N (APN, EC 3.4.11.2.), and ebelactone A, an esterase inhibitor. These effects resulted, as expected, in decreased cytotoxic effects of J1. A specific role of APN in hydrolyzing J1 releasing free melphalan was demonstrated in vitro with pure APN enzyme. By using plasmid-based overexpression of APN or down regulation of endogenous APN with siRNA in different tumor cell lines we here confirm the involvement of APN in J1-mediated cytotoxic and apoptotic signaling. In conclusion, this study demonstrates a role of APN in the activation of the melphalan prodrug J1 and subsequently, its cytotoxicity. Given that APN is shown to be overexpressed in several solid tumors our data suggest that J1 may be activated in a tumor selective manner.
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| 2. |
- Eriksson, Mina, et al.
(författare)
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Analysis of Chromatin Opening in Heterochromatic Non-Small Cell Lung Cancer Tumor-Initiating Cells in Relation to DNA-Damaging Antitumor Treatment
- 2018
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016 .- 1879-355X. ; 100:1, s. 174-187
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: We previously reported that sphere-forming non-small cell lung cancer (NSCLC) tumor-initiating cells (TICs) have an altered activation of DNA damage response-and repair proteins and are refractory to DNA-damaging treatments. We analyzed whether chromatin organization plays a role in the observed refractoriness.Methods and Materials: Bulk cells and TICs from the NSCLC H23 and H1299 cell lines were examined using cell viability, clonogenic survival, Western blot, short interfering RNA analysis, and micronucleus assay.Results: NSCLC TICs displayed elevated heterochromatin markers trimethylated lysine 9 of histone H3 and heterochromatin protein 1 gamma relative to bulk cells and reduced cell viability upon histone deacetylase inhibition (HDACi). Vorinostat and trichostatin A increased the euchromatin markers acetylated lysine 9/14 of histone H3 and lysine 8 of histone H4, and HDACi pretreatment increased the phosphorylation of the DNA damage response proteins ataxia telangiectasia mutated and DNA-dependent protein kinase, catalytic subunit, upon irradiation in TICs. HDACi sensitized TICs to cisplatin and to some extent to ionizing irradiation. The protectiveness of a dense chromatin structure was indicated by an enhanced frequency of micronuclei in TICs following irradiation, after knockdown of heterochromatin protein 1 gamma.Conclusions: Although confirmatory studies in additional NSCLC model systems and with respect to analyses of other DNA damage response proteins are needed, our data point toward a heterochromatic structure of NSCLC TICs, such that HDACi can sensitize TICs to DNA damage.
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| 6. |
- Nilsson, Kjell G, et al.
(författare)
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Assessment of horizontal laminar air flow instrument table for additional ultraclean space during surgery
- 2010
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Ingår i: Journal of Hospital Infection. - : Elsevier. - 0195-6701 .- 1532-2939. ; 76:3, s. 243-246
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Tidskriftsartikel (refereegranskat)abstract
- The area in a vertical ultraclean laminar air flow (LAF) theatre is usually too small to accommodate all the equipment needed for major surgery. We investigated the addition of an instrument table supplied with fixed ultraclean LAF and placed alongside the existing main LAF unit, to determine its physical and bacteriological effect on the main unit. In phase 1, with two investigators but without a patient, smoke tests showed no intrusion of air from the table into the main unit and particle counts did not show any adverse effect on the main LAF unit. In phase 2, during patients undergoing two total knee replacements, the LAF table and a table without LAF were placed alongside the main LAF unit. The tables were subjected to the activity of an extra operating room (OR) nurse working from inside the main LAF vigorously simulating handling of instruments. During this activity, the >5 μm particle counts were 275/m3 at the instrument table with LAF and 8550/m3 at the table without LAF (P < 0.0001). Also, without the OR nurse activity, the particle counts, just inside the main unit and adjacent to the LAF table, were significantly reduced (P < 0.03–0.003). Sedimentation plates on the LAF table and in the main unit registered 22 and 25 cfu/m2/h respectively compared with 45 cfu/m2/h at the instrument table without LAF. In conclusion, the results from the smoke tests, particle counts and bacteriological evaluation showed that the additional instrument table supplied with LAF is efficient and can be safely used as an extension additional to a main OR LAF unit.
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| 9. |
- Rolf, Julia, et al.
(författare)
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The enlarged population of marginal zone/CD1d(high) B lymphocytes in nonobese diabetic mice maps to diabetes susceptibility region Idd11.
- 2005
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Ingår i: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 174:8, s. 4821-4827
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Tidskriftsartikel (refereegranskat)abstract
- The NOD mouse is an important experimental model for human type 1 diabetes. T cells are central to NOD pathogenesis, and their function in the autoimmune process of diabetes has been well studied. In contrast, although recognized as important players in disease induction, the role of B cells is not clearly understood. In this study we characterize different subpopulations of B cells and demonstrate that marginal zone (MZ) B cells are expanded 2- to 3-fold in NOD mice compared with nondiabetic C57BL/6 (B6) mice. The NOD MZ B cells displayed a normal surface marker profile and localized to the MZ region in the NOD spleen. Moreover, the MZ B cell population developed early during the ontogeny of NOD mice. By 3 wk of age, around the time when autoreactive T cells are first activated, a significant MZ B cell population of adult phenotype was found in NOD, but not B6, mice. Using an F2(B6 x NOD) cross in a genome-wide scan, we map the control of this trait to a region on chromosome 4 (logarithm of odds score, 4.4) which includes the Idd11 and Idd9 diabetes susceptibility loci, supporting the hypothesis that this B cell trait is related to the development of diabetes in the NOD mouse.
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