Quinazoline derivative from indigenous isolate, Nocardiopsis alba inhibits human telomerase enzyme.

AIM: Aim of this study was isolation and screening of various secondary metabolites produced by indigenous isolates of soil Actinomycetes for human telomerase inhibitory activity. METHODS AND RESULTS: Extracellular extract from culture suspension of various soil Actinomycetes species were tested for telomerase inhibitory activity. The organism which produced telomerase inhibitor was identified by 16S rRNA gene sequencing. The active fraction was purified by HPLC and analysed by GC-MS to identify the compound. In GC-MS analysis, the active principle was identified as 3-[4'-(2″-chlorophenyl)-2'-thiazolyl]-2,4-dioxo-1,2,3,4-tetrahydro quinazoline. The G-quadruplex stabilizing ability of the compound was checked by molecular docking and simulation experiments with G-quadruplex model (PDB ID-1L1H). The selective binding ability of the compound with G-quadruplex over Dickerson-Drew dodecamer DNA structures showed that the compound possess high selectivity towards G-quadruplex. CONCLUSIONS: Quinazoline derivative isolated from an indigenous strain of Nocardiopsis alba inhibited telomerase. Molecular docking and simulation studies predicted that this compound is a strong stabilizer of G-quadruplex conformation. It also showed a preferable binding to G-quadruplex DNA over normal DNA duplex. SIGNIFICANCE AND IMPACT OF THE STUDY: This particular compound can be suggested as a suitable compound for developing a future anticancer drug. The selectivity towards G-quadruplex over normal DNA duplex gives a clue that it is likely to show lower cytotoxicity in normal cells.

Long term results of postoperative Intensity-Modulated Radiation Therapy (IMRT) in the treatment of Squamous Cell Carcinoma (SCC) located in the oropharynx or oral cavity.

BACKGROUND: To report our long-term results with postoperative intensity-modulated radiation therapy (IMRT) in patients suffering from squamous-cell carcinoma (SCC) of the oral cavity or oropharynx. METHODS: Seventy five patients were retrospectively analyzed. Median age was 58 years and 84 % were male. 76 % of the primaries were located in the oropharynx. Surgery resulted in negative margins (R0) in 64 % of the patients while 36 % suffered from positive margins (R1). Postoperative stages were as follows: stage 1:4 %, stage 2:9 %, stage 3:17 %, stage 4a:69 % with positive nodes in 84 %. Perineural invasion (Pn+) and extracapsular extension (ECE) were present in 7 % and 29 %, respectively. All patients received IMRT using the step-and-shoot approach with a simultaneously integrated boost (SIB) in 84 %. Concurrent systemic therapy was applied to 53 patients, mainly cisplatin weekly. RESULTS: Median follow-up was 55 months (5-150). 13 patients showed locoregional failures (4 isolated local, 4 isolated neck, 5 combined) transferring into 5-year-LRC rates of 85 %. Number of positive lymph nodes (n > 2) and presence of ECE were significantly associated with decreased LRC in univariate analysis, but only the number of nodes remained significant in multivariate analysis. Overall treatment failures occurred in 20 patients (9 locoregional only, 7 distant only, 4 combined), transferring into 3-and 5-year-FFTF rates of 77 % and 75 %, respectively. The 3-and 5-year-OS rates were 80 % and 72 %, respectively. High clinical stage, high N stage, number of positive nodes (n > 2), ECE and Pn1 were significantly associated with worse FFTF and OS in univariate analysis, but only number of nodes remained significant for FFTF in multivariate analysis. Maximum acute toxicity was grade 3 in 64 % and grade 4 in 1 %, mainly hematological or mucositis/dysphagia. Maximum late toxicity was grade 3 in 23 % of the patients, mainly long-term tube feeding dependency. CONCLUSION: Postoperative IMRT achieved excellent LRC and good OS with acceptable acute and low late toxicity rates. The number of positive nodes (n > 2) was a strong prognostic factor for all endpoints in univariate and the only significant factor for LRC and FFTF in multivariate analysis. Patients with feeding tubes due to postoperative complications had an increased risk for long-term feeding tube dependency.

Association between serum ferritin level and diastolic cardiac function in patients with major ß-thalassemia.

BACKGROUND: Prevention of myocardial siderosis is a key step to reduce rate of mortality in thalassemic patients. Our objective was to study association between echocardiography parameters and serum ferritin level in patients with major thalassemia. MATERIALS AND METHODS: Sixty-six patients with major thalassemia were studied in Amir Kabir hospital, Arak, Iran. Serum ferritin levels were measured during 3 months in patients with no symptoms of infection. It was measured by enzyme-linked immunosorbent assay (ELISA). Ejection Fraction (EF), Fractional Shortening (FS) and Early/Late ratio (E/A) were studied by echocardiography. RESULTS: Fifty two percent were female and 48% were male. Mean age was 16 ± 9 years and the age range was3-26years. Mean serum ferritin level was1912 ± 1748 ng/dl and its range was from 303 to 8333 ng/dl. There were significant correlations between serum ferritin level and EF(r=0.3 and P=0.05) and also between serum ferritin level and FS. CONCLUSION: Due to significant association between serum ferritin level and echo parameters, it is beneficial that all patients with major thalassemia undergo echocardiography to gain better understating about cardiac function.

Association between serum ferritin level, cardiac and hepatic T2-star MRI in patients with major ß-thalassemia.

BACKGROUND: Frequent blood transfusion is often associated with iron overload. Proper use of iron chelators to treat iron overload requires an accurate measurement of iron levels. Magnetic resonance T2-star (T2* MRI) can measure iron level in the heart and liver. Our goal was to see whether an association exists between serum ferritin level and T2* MRI in patients with major beta thalassemia. MATERIALS AND METHODS: Sixty patients with a diagnosis of major beta thalassemia were enrolled in the study. They were older than five years old and needed regular transfusion. Cardiac and hepatic T2*MRI and mean serum ferritin levels were measured within 3 months. RESULTS: No significant correlation was observed between serum ferritin level and cardiac T2*MRI (p=0.361, r=-0.120).However, a significant correlation was observed between serum ferritin and liver T2*MRI (p=0.021, r=-0.297). CONCLUSION: Our results showed an association between hepatic T2*MRI and serum ferritin level.

Hemocyte responses of the Colorado potato beetle, Leptinotarsa decemlineata, and the greater wax moth, Galleria mellonella, to the entomopathogenic nematodes, Steinernema feltiae and Heterorhabditis bacteriophora.

Hemocyte encapsulation reactions of infective juveniles of two Iranian isolates of the entomopathogenic nematodes, Heterorhabditis bacteriophora Poinar (Rhabditina: Heterorhabditidae) and Steinernema feltiae Filipjev (Tylenchina: Steinernematidae), were compared in the economic pest Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), and the greater wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae). The former was a more responsive host than the latter and the hemocyte responses occurred sooner and more extensively. Complete encapsulation of some of the nematodes occurred by 4 h post injection for H. bacteriophora in both L. decemlineata and G. mellonella, and by 2 h pi for S. feltiae in L. decemlineata. The percentage of encapsulation from 24 h to 72 h pi in L. decemlineata was 86.2% for S. feltiae and 39% for H. bacteriophora. In G. mellonella there were no encapsulation or melanization responses against S. feltiae, whereas when H. bacteriophora was encapsulated and melanized (16.7%) the encapsulation level was lower than in L. decemlineata. This study may contribute to effectively selecting entomopathogenic nematode species active against significant economic pests based on the latter's cellular immune response.