Fragment-type 4-azolylcoumarin derivatives with anticancer properties.

Several coumarin derivatives with a directly attached azole substituent at C-4 were synthesized and biologically studied for their anticancer properties. The cell lines used for this investigation (HeLa, K-562, MDA-MB-53, and MCF-7) demonstrated different sensitivities. The best response in the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay was shown by K-562 cells, with compounds displaying activity (3c, IC50 3.06 µM; 4a, IC50 5.24 µM; 4c, IC50 4.7 µM) similar to that of cisplatin (IC50 ~6 µM), which was used as the standard. The studied azole-substituted coumarins demonstrated weaker activity toward other cell lines, except for compound 4c, which was equally potent in the case of MCF-7 cells. Additional biological evaluations supported interference with the cell cycle as a potential mechanism of action and confirmed the absence of toxicity in zebrafish embryos. On the basis of these initial results, 4-azole coumarins should be explored further. Although their activity would need additional optimization, the fact that these compounds are fragment-like structures with MW <300 and clog P <3 offers enough flexibility to fine-tune their drug-like properties.

Preparation of pyrrolizinone derivatives via sequential transformations of cyclic allyl imides: synthesis of quinolactacide and marinamide.

A facile synthetic route has been developed for the preparation of pyrrolizinone derivatives employing N-allyl imides as starting materials. The nucleophilic addition of a vinyl Grignard reagent/RCM/elimination sequence afforded pyrrolizinones in good yields and has been applied for the preparation of naturally occurring quinolactacide and marinamide.

From PROTAC to inhibitor: Structure-guided discovery of potent and orally bioavailable BET inhibitors.

An X-ray structure of a CLICK chemistry-based BET PROTAC bound to BRD2(BD2) inspired synthesis of JQ1 derived heterocyclic amides. This effort led to the discovery of potent BET inhibitors displaying overall improved profiles when compared to JQ1 and birabresib. A thiadiazole derived 1q (SJ1461) displayed excellent BRD4 and BRD2 affinity and high potency in the panel of acute leukaemia and medulloblastoma cell lines. A structure of 1q co-crystalised with BRD4-BD1 revealed polar interactions with the AZ/BC loops, in particular with Asn140 and Tyr139, rationalising the observed affinity improvements. In addition, exploration of pharmacokinetic properties of this class of compounds suggest that the heterocyclic amide moiety improves drug-like features. Our study led to the discovery of potent and orally bioavailable BET inhibitor 1q (SJ1461) as a promising candidate for further development.

Possible interactions of genetic and immuno-neuro-endocrine regulatory mechanisms in pathogenesis of congenital anomalies.

The process of organogenesis depends on genetic and environmental factors. Besides genetic background, congenital anomalies can also be influenced by micro environmental changes, which are related to maternal-foetal interactions followed by the production of cytokines, hormones, neurotransmitters, growth factors and biochemical mediators, and stress proteins. Pre-natal maternal stress, including infections, psychological stress and other teratogens, can influence a disregulation of maternal immune, endocrine and nervous systems, during pregnancy. This is a crucial condition for the abnormal growth and development of the foetus. Activated maternal immune system can alter the cytokine network and make it inadequate for normal embryogenesis and organogenesis. Heat-shock proteins play an important role in stress physiology repairing DNA errors or activating pro-inflammatory response. Regarded from this aspect, the altered cytokine network suggests aetiopathogenetic basis of congenital anomalies in neonates. It is our wish to point out our potentially harmful conditions in the development of congenital anomalies, as well as their control by using pre-natal and pre-conceptional diagnostics and treatment.

Hepatitis C virus genotypes and the development of hepatocellular carcinoma.

OBJECTIVE: The aim of this study was to investigate the prevalence of hepatitis C virus (HCV) infection in patients with hepatocellular carcinoma (HCC) in our geographic area, and to determine if there is a correlation between HCV genotypes and the development of HCC. METHODS: Thirty-six patients with HCV-related HCC and 35 controls with HCV-associated cirrhosis without HCC were studied. The diagnosis of HCV infection was performed by the enzyme-linked immunosorbent assay test for the detection of anti-HCV antibodies and by reverse transcription-polymerase chain reaction for the detection of HCV-RNA. HCV genotyping was performed by line probe assay-Inno-LIPA HCV II. The diagnosis of underlying disease in the patients with HCC was performed on the basis of clinical, biochemical or histological evidence. RESULTS: Genotype 1b was found in 28 (77.77%) patients with HCC, and in 16 (45.71%) controls. There was significant difference in the prevalence of genotype 1b between the patients with HCC and those with cirrhosis without HCC (P<0.05). Having analyzed the diagnosis of underlying diseases, underlying cirrhosis in 29 (80.55%) and chronic active hepatitis in 7 (19.44%) patients with HCC was found. CONCLUSION: Results of the present study suggest that there is a correlation between HCV genotype 1b and the development of HCC. Our findings also add support to the hypothesis that cirrhosis is a major step in liver carcinogenesis associated with HCV, which suggests an indirect role of HCV in the pathogenesis of HCC.

Serum anti-Helicobacter pylori IgA and IgG antibodies in asymptomatic children in Serbia.

The aim of this study was to determine the seroprevalence of Helicobacter pylori and the distribution of anti-H.pylori IgA and IgG antibodies in asymptomatic children aged between 7 and 18 y. We studied the serum samples of 283 children using the commercial ELISA test for the detection of anti-H. pylori IgA and IgG antibodies. The overall prevalence of anti-H. pylori antibodies was 36.4%. The seroprevalence was 35%, 28.3%, 37.5%, and 42.2% for the ages of 7, 10, 14 and 18 y, respectively. Serum IgG antibodies alone were detected in 88.3%, IgA alone in 4.9%, and both IgA and IgG antibodies were detected in 6.8% of samples. The mean levels of IgG antibodies to H. pylori increased with age. We concluded that the prevalence of H. pylori antibodies in Serbian children was high (36.4%), ranging from 35% to 42.2%. The detection of IgG antibodies is useful for the determination of seroprevalence in asymptomatic children.

[Detection of Helicobacter pylori in gastric biopsy and resection specimens]. / Otkrivanje Helicobactera pylori u uzorcima dobijenim biopsijom i resekcijom zeluca.

AIM: To compare the sensitivity of detecting H. pylori in gastric biopsy and resection specimens using modified Giemsa stain and immunohistochemistry, using a commercially available anti-H. pylori antibody (Dako, Denmark). METHODS: Gastric antral biopsy specimens showing chronic gastritis (28 cases) together with tissue blocks from gastrectomy specimens for duodenal ulcer (2 cases) were stained with modified Giemsa and immunoenzymatic alkaline phosphatase - anti-alkaline phosphatase (APAAP) method, and were carefully examined for the presence of H. pylori. RESULTS: Using a modified Giemsa stain, the spiral shaped bacteria of H. pylori stained blue, were attached to the brush border of the gastric foveolar epithelial cells. However, the specificity of modified Giemsa stain depended on the morphological appearance of H. pylori. The specificity of immunostaining permitted detection of low numbers or even single organisms. In all cases bacteria were more prominent and easier to detect in immunostained preparations. H. pylori was identified in 22 (73.3%) of 30 sections stained with modified Giemsa stain, but it could be identified with greater frequency in sections stained with APAAP, in 27 (90%) of 30 sections. CONCLUSION: Immunohistochemical identification of H. pylori was better than Giemsa stain for detecting that organism.