Nonsteroidal anti-inflammatory drugs and their analogues as inhibitors of aldo-keto reductase AKR1C3: new lead compounds for the development of anticancer agents

Nonsteroidal anti-inflammatory drugs (NSAIDs) like indomethacin, flufenamic acid, and related compounds have been recently identified as potent inhibitors of AKR1C3. We report that some other NSAIDs (diclofenac and naproxen) also inhibit AKR1C3, with the IC(50) values in the low micromolar range. In order to obtain more information about the structure-activity relationship and to identify new leads, a series of compounds designed on the basis of NSAIDs were synthesized and screened on AKR1C3. The most active compounds were 2-[(2,2-diphenylacetyl)amino]benzoic acid 4 (IC(50)=11microM) and 3-phenoxybenzoic acid 10 (IC(50)=0.68microM). These compounds represent promising starting points for the development of new anticancer agents.     

Amplification of KIT, PDGFRA, VEGFR2, and EGFR in gliomas

Receptor tyrosine kinase aberrations are implicated in the genesis of gliomas. We investigated expression and amplification of KIT, PDGFRA, VEGFR2, and EGFR in 87 gliomas consisting of astrocytomas, anaplastic astrocytomas, oligodendrogliomas, or oligoastrocytomas in tumor samples collected at the time of the diagnosis and in samples of the same tumors at tumor recurrence. Gene amplifications were investigated using either chromogenic in situ hybridization or fluorescence in situ hybridization, and protein expression using immunohistochemistry. In samples collected at glioma diagnosis, KIT and PDGFRA amplifications were more frequent in anaplastic astrocytomas than in astrocytomas, oligodendrogliomas, and oligoastrocytomas [28% versus 5% (P = 0.012) and 33% versus 2% (P = 0.0008), respectively]. VEGFR2 amplifications occurred in 6% to 17% of the gliomas at diagnosis, and EGFR amplifications in 0% to 12%. Amplified KIT was more frequently present in recurrent gliomas than in newly diagnosed gliomas (P = 0.0066). KIT amplification was associated with KIT protein expression and with presence of PDGFRA and EGFR amplifications both at the time of the first glioma diagnosis and at tumor recurrence, and with VEGFR2 amplification at tumor recurrence. Three (4%) primary gliomas and 10 (14%) recurrent gliomas that were evaluable for coamplification of KIT, PDGFRA, and VEGFR2 showed amplification of at least two of these genes; the amplicon contained amplified KIT in all 13 cases. In conclusion, besides glioblastoma, amplified KIT, PDGFRA, and VEGFR may also occur in lower-grade gliomas and in their recurrent tumors. It is currently not known whether specific tyrosine kinase inhibitors are effective in the treatment of such gliomas.     

The circulatory influence on development of age-related macular degeneration and hearing and equilibrium impairments

This study attempts to answer the question if any level of head and neck circulation takes a part in development of Age-Related Macular Degeneration (ARMD) and hearing and equilibrium impairments. Condition of large blood vessels was examined by Color-Doppler ultrasound, and carotid and ophthalmic arteries were included. The microcirculatory changes were examined directly by fundus photography and fluorescein angiography and indirectly testing hearing and equilibrium. The study group included 40 patients (21 females, 19 males) aging from 53 to 84 years with different stages of ARMD. The control group included 40 patients (18 females, 22 males) aging from 51 to 82 years without ARMD. Patients were inhabitants of Primorsko-Goranska County. There was no relationship between ARMD and condition of large blood vessels because significant stenosis of carotid arteries was found in 2 patients (5%) in study group and 3 patients (7.5%) in the control group (p > 0.05). On the contrary, we found correlation between ARMD and hearing (p = 0.0127) and equilibrium impairments (p = 0.0242). Fluorescein angiograms shows raised number of ischemic retinal capillaries in patients with ARMD (p = 0.0053). Results lead to conclusion that circulatory disorders on microcirculatory level take a great part in development of ARMD and hearing and equilibrium impairments in the elderly. The key is damage of sensory cells of the retina and inner ear caused by microcirculatory disorders. Interesting data was noticed that 9 patients with more serious ARMD on one side of head had greater hearing loss on the same side. If we find a new treatment for microcirculatory disorders, maybe we can treat both sensory impairments in earlier stage.     

Pseudoexfoliative syndrome and pseudoexfoliative glaucoma in Primorsko-Goranska County

The aim of this study is to evaluate pseudoexfoliative glaucoma (PEX) in Primorsko-Goranska County, Croatia, and its characteristics comparing to primary open angle glaucoma (POAG). In the study a hundred patients with open angle glaucoma were examined, twenty six of them had a pseudoexfoliative glaucoma diagnosed. We were following intraocular pressure (IOP) values, visual acuities, visual fields and optical nerve head changes retrospectively. Comparing to primary open angle glaucoma pseudoexfoliative glaucoma in Primorsko-Goranska County has less good prognosis because the IOP is usually higher and more difficult to control, we found progressive loss of retinal ganglion cells and visual field loss develop more rapidly. Because of that pseudoexfoliative glaucoma requires special treatment and following.     

Focused high risk--population screening for carotid stenosis and retinal microangiopathia after radiotherapy for laryngeal carcinoma

Carotid artery stenosis (CAS) is one of the major complications of external irradiation (radiotherapy, RT) for laryngeal carcinoma. Considering amaurosis fugax is often one of the first signs of significant CAS our focus was to determine weather patients with post-irradiation CAS also develop ocular microangiopathy as a result of insufficient ophthalmic circulation. In our study Carotid Duplex ultrasound scans revealed that 33.33% of patients had significant radiation-induced CAS. The majority (over 85.71%) of radiation-induced CAS had more than one atherosclerotic plaque including any degree of stenosis in the RT group, and had significantly more than that of the control group. Microangiopathic changes were documented only with the patients that have had an increased cerebrovascular risk (diabetes mellitus and arterial hypertension).     

Characteristics of people with the perceived stress in croatia: the CroHort study

This study aimed to assess levels of stress in Croatian adult population using PSS, in a population study (Croatian Adult Cohort Health Study - CroHort). Our results show that the levels of stress were 17.46 (SD = 6.73) for men and 18.32 (SD = 6.46) for women in Croatia. The lowest levels of stress experienced men living in urban area while women living in rural area had the highest level. Men and women who had university degree had significantly lower level of stress. The lowest levels of stress experienced participants who had much better financial condition than average. In men, stress was associated to weak heart, lower back pain, poor financial condition of the household and high alcohol consumption. In women, stress was associated to poor mental health, poor social functioning, poorer financial condition of the household, higher age, lower education, low monthly income of the household and poor general health.     

Insights into subtle conformational differences in the substrate-binding loop of fungal 17β-hydroxysteroid dehydrogenase: a combined structural and kinetic approach

The 17β-HSD (17β-hydroxysteroid dehydrogenase) from the filamentous fungus Cochliobolus lunatus (17β-HSDcl) is a NADP(H)-dependent enzyme that preferentially catalyses the interconversion of inactive 17-oxo-steroids and their active 17β-hydroxy counterparts. 17β-HSDcl belongs to the SDR (short-chain dehydrogenase/reductase) superfamily. It is currently the only fungal 17β-HSD member that has been described and represents one of the model enzymes of the cP1 classical subfamily of NADPH-dependent SDR enzymes. A thorough crystallographic analysis has been performed to better understand the structural aspects of this subfamily and provide insights into the evolution of the HSD enzymes. The crystal structures of the 17β-HSDcl apo, holo and coumestrol-inhibited ternary complex, and the active-site Y167F mutant reveal subtle conformational differences in the substrate-binding loop that probably modulate the catalytic activity of 17β-HSDcl. Coumestrol, a plant-derived non-steroidal compound with oestrogenic activity, inhibits 17β-HSDcl [IC50 2.8?μM; at 100?μM substrate (4-oestrene-3,17-dione)] by occupying the putative steroid-binding site. In addition to an extensive hydrogen-bonding network, coumestrol binding is stabilized further by π-π stacking interactions with Tyr212. A stopped-flow kinetic experiment clearly showed the coenzyme dissociation as the slowest step of the reaction and, in addition to the low steroid solubility, it prevents the accumulation of enzyme-coenzyme-steroid ternary complexes.     

Steroid-transforming enzymes in fungi

Fungal species are a very important source of many different enzymes, and the ability of fungi to transform steroids has been used for several decades in the production of compounds with a sterane skeleton. Here, we review the characterised and/or purified enzymes for steroid transformations, dividing them into two groups: (i) enzymes of the ergosterol biosynthetic pathway, including data for, e.g. ERG11 (14α-demethylase), ERG6 (C-24 methyltransferase), ERG5 (C-22 desaturase) and ERG4 (C-24 reductase); and (ii) the other steroid-transforming enzymes, including different hydroxylases (7α-, 11α-, 11β-, 14α-hydroxylase), oxidoreductases (5α-reductase, 3β-hydroxysteroid dehydrogenase/isomerase, 17β-hydroxysteroid dehydrogenase, C-1/C-2 dehydrogenase) and C-17-C-20 lyase. The substrate specificities of these enzymes, their cellular localisation, their association with protein super-families, and their potential applications are discussed. Article from a special issue on steroids and microorganisms.