Ebubekir Dirican

A modulator against mercury chloride-induced genotoxic damage: Dermatocarpon intestiniforme (L.)

Mercury has been used in many domains of human activities for many years, although in any form mercury is reported to be toxic. On the other hand, lichens have been used in the treatment of several diseases such as tuberculosis, hemorrhoids, ulcer, dysentery and cancer. Animal investigations on some common lichen species have demonstrated their antioxidant and antimutagenic activity. However, there is very scarce data on the medical or biologic effects of specific lichen species. Therefore, in the present study, we assessed the cyotogenetic effects of mercuric chloride (HgCl2) and the role of aqueous Dermatocarpon intestiniforme lichen extracts in mercury-treated human blood cultures (n = 3). The sister chromatid exchange (SCE) and micronucleus (MN) assays were performed to assess DNA damages in lymphocytes. Our results clearly revealed that the SCE and MN rates induced by HgCl2 were alleviated by the presence of D. intestiniforme. In conclusion, the results of the present study revealed for the first time that the lichen D. intestiniforme provided increased resistance of DNA against HgCl2-induced genetic damage on human lymphocytes.

The evaluation of the genotoxic and oxidative damage potentials of Ulothrix tenuissima (Kütz.) in vitro

Several alga species are known to produce a variety of toxic metabolites that pose a threat to aquatic organisms, animals and humans. Moreover, these metabolites have been thought to cause serious diseases including certain cancers and neurodegenerative disorders. On the other hand, Ulothrix is a genus of filamentous green algae, generally found in fresh water and marine and abundantly available in some lakes and rivers of Turkey. To our best knowledge, no study has been performed to assess the genotoxic and biochemical effects of U. tenuissima on cultured human blood cells. Therefore, in order to determine clastogenic or aneugenic effects of aqueous alga extracts the micronucleus assay was carried out. Nuclear division index (NDI) in peripheral lymphocytes was also analyzed for cytotoxicity evaluations. In addition, biochemical parameters (total antioxidant capacity (TAC) and total oxidative stress (TOS)) were examined to determine oxidative effects. For this aim, we obtained heparinized blood samples from three healthy persons. The alga samples were collected from Porsuk Pond in Hasankale (Erzurum, Turkey) in summer period of the year 2010. The aqueous extracts of this species were added to cultures at different concentrations (0 to 5000 ppm) for 72 h. Our results showed that this alga did not cause any statistically important changes in the rates of studied genotoxicity endpoint. But dose-dependent alterations were observed in TAC and TOS levels and NDI rates. In conclusion, U. tenuissima was found to be non-genotoxic but caused sterility at higher concentrations due to oxidative stress.

Detection of PIK3CA Gene Mutations with HRM Analysis and Association with IGFBP-5 Expression Levels in Breast Cancer

Breast cancer is the second most common cancer and second leading cause of cancer deaths in women. Phosphatidylinositol-3-kinase (PI3K)/AKT pathway mutations are associated with cancer and phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene mutations have been observed in 25-45% of breast cancer samples. Insulin growth factor binding protein-5 (IGFBP-5) can show different effects on apoptosis, cell motility and survival in breast cancer. We here aimed to determine the association between PIK3CA gene mutations and IGFBP-5 expressions for the first time in breast cancer patients. Frozen tumor samples from 101 Turkish breast cancer patients were analyzed with high resolution melting (HRM) for PIK3CA mutations (exon 9 and exon 20) and 37 HRM positive tumor samples were analyzed by DNA sequencing, mutations being found in 31. PIK3CA exon 9 mutations (Q546R, E542Q, E545K, E542K and E545D) were found in 10 tumor samples, exon 20 mutations (H1047L, H1047R, T1025T and G1049R) in 21, where only 1 tumor sample had two exon 20 mutations (T1025T and H1047R). Moreover, we detected one sample with both exon 9 (E542Q) and exon 20 (H1047R) mutations. 35% of the tumor samples with high IGFBP-5 mRNA expression and 29.4% of the tumor samples with low IGFBP-5 mRNA expression had PIK3CA mutations (p=0.9924). This is the first study of PIK3CA mutation screening results in Turkish breast cancer population using HRM analysis. This approach appears to be a very effective and reliable screening method for the PIK3CA exon 9 and 20 mutation detection. Further analysis with a greater number of samples is needed to clarify association between PIK3CA gene mutations and IGFBP-5 mRNA expression, and also clinical outcome in breast cancer patients.

The genotoxic potentials of some atypical antipsychotic drugs on human lymphocytes.

Olanzapine (OLZ), risperidone (RPD) and quetiapine (QTP) are atypical antipsychotic drugs and are commonly used for the treatments of schizophrenia and bipolar disorders. However, recent reports indicated that these drugs could exhibit toxic effects on nervous and cardiovascular systems. To our best knowledge, there are scarce data considering the genotoxic damage potentials of OLZ, RPD and QTP on human lymphocyte culture system. Therefore, in this study, the genotoxic potentials of OLZ, RPD and QTP (0–400 mg/L) have been evaluated in human whole blood cultures (WBCs; n = 4). The single cell gel electrophoresis (SCGE) and micronucleus (MN) assays were applied to estimate the DNA damage. The results of the present study indicated that the tested antipsychotic drug did not induce genotoxicity. In fact, the mean values of the total scores of cells showing DNA damage (for SCGE assay) and MN/1000 cell were not found significantly different from the control values (p > 0.05). However, the application of the highest drug concentrations (250 mg/L and above) caused the sterility in lymphocyte cultures. It is concluded that the tested three different atypical antipsychotic drugs can be used safely, but it is necessary to consider the cytotoxic effects that are likely to appear depending on the doses exposed.

Serratia ficaria isolated from sputum specimen.

Serratia ficaria was first described in 1979 as a Gram-negative facultative anaerobic rod. S. ficaria was found in figs, but also isolated from human specimens in a few cases. We now report an isolate of S. ficaria from sputum specimen.A 46-year-old man was suffering from a chronic renal failure of five years, four months of peritoneal dialysis and one week of fever due to respiratory tract infection, accompanied by cough. Sputum culture yielded a Gram-negative rod. It was identified as S. ficaria and the antibiotic susceptibility test was performed by automated Vitek II (bioMerieux). The tested S. ficaria strain was susceptible to amikacin, gentamicin, cefepime, trimethoprim-sulfamethoxazole, imipenem, meropenem, tigecycline and ciprofloxacin. This strain was resistant to ampicillin, amoxicillin-clavulanic acid, cephalothin, cefoxitine, cefuroxime and ceftriaxone. The patient was treated successfully (80 mg trimethoprim/400 mg sulfamethoxazole twice daily for 7 days)S. ficaria is an opportunistic pathogen responsible for intestinal colonization or serious infections such as septicaemia, gall bladder empyema in immunocompromised patients. The fig tree and fig play an important role in human colonization. It should be remembered that S. ficaria infections may be encountered frequently especially in fig tree culture zones.

Phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog as therapeutic targets in breast cancer

Breast cancer is the most commonly diagnosed cancer among women in Turkey and worldwide. It is considered a heterogeneous disease and has different subtypes. Moreover, breast cancer has different molecular characteristics, behaviors, and responses to treatment. Advances in the understanding of the molecular mechanisms implicated in breast cancer progression have led to the identification of many potential therapeutic gene targets, such as Breast Cancer 1/2, phosphatidylinositol 3-kinase catalytic subunit alpha, and tumor protein 53. The aim of this review is to summarize the roles of phosphatidylinositol 3-kinase regulatory subunit 1 (alpha) (alias p85α) and phosphatase and tensin homolog in breast cancer progression and the molecular mechanisms involved. Phosphatase and tensin homolog is a tumor suppressor gene and protein. Phosphatase and tensin homolog antagonizes the phosphatidylinositol 3-kinase/AKT signaling pathway that plays a key role in cell growth, differentiation, and survival. Loss of phosphatase and tensin homolog expression, detected in about 20%–30% of cases, is known to be one of the most common tumor changes leading to phosphatidylinositol 3-kinase pathway activation in breast cancer. Instead, the regulatory subunit p85α is a significant component of the phosphatidylinositol 3-kinase pathway, and it has been proposed that a reduction in p85α protein would lead to decreased negative regulation of phosphatidylinositol 3-kinase and hyperactivation of the phosphatidylinositol 3-kinase pathway. Phosphatidylinositol 3-kinase regulatory subunit 1 protein has also been reported to be a positive regulator of phosphatase and tensin homolog via the stabilization of this protein. A functional genetic alteration of phosphatidylinositol 3-kinase regulatory subunit 1 that results in reduced p85α protein expression and increased insulin receptor substrate 1 binding would lead to enhanced phosphatidylinositol 3-kinase signaling and hence cancer development. Phosphatidylinositol 3-kinase regulatory subunit 1 underexpression was observed in 61.8% of breast cancer samples. Therefore, expression/alternations of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog genes have crucial roles for breast cancer progression. This review will summarize the biological roles of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog in breast cancer, with an emphasis on recent findings and the potential of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog as a therapeutic target for breast cancer therapy.

High Resolution Melting Method in Molecular Diagnostics and Their Clinical Importance

Her gecen gun molekuler biyoloji alaninda teknolojinin gelismesiyle paralel, bircok yeni molekuler analiz yontemleri ortaya cikmaktadir. Biz de bu derlemede, molekuler tanida onemli oldugu gosterilmis olan Yuksek Cozunurluklu Erime (High Resolution Melting) (HRM) analizini, uygulama alanlarini ve klinikte yapilmis calismalarla onemini anlatmayi amacladik. HRM kapali tup sisteminde, Polimeraz Zincir Reaksiyonu (PZR: PCR) sonrasina dayali genetik varyasyonlari belirlemek icin kullanilan yeni bir yontemdir. HRM’nin calisma prensibi nukleik asit orneklerinin erime davranisina dayanmaktadir. Cift zincirli DNA’nin denaturasyonu erime sicakliginin artmasiyla olusan floresan degisikliklerinin saptanmasiyla belirlenir. Wild type (yaban tip) ve heterozigot orneklerinin farkliliklari erime grafiklerinde kolaylikla saptanabilmektedir. Bu yontemde erime egrisi analiziyle daha fazla bilgi ve detay elde edilebilmektedir. HRM analizi, orneklerin sekans, uzunluk, guanin sitozin (GC) icerigine gore ayrimini yapabilmektedir. Populasyonda yaygin gorulen tek nukleotit degisikliklerinin (SNP) tespiti, hastaliklarla iliskili gen mutasyon taramalari ve DNA metilasyon analizleri HRM yontemi ile hizli ve guvenilir bir sekilde tanimlanabilmektedir. PZR urunlerindeki nukleotit dizi degisimleri ve cesitli varyasyonlar DNA erime egrisi sekilleriyle HRM yonteminde saptanabilmektedir. Kombine yeni nesil DNA boyalari ve gelistirilen gen tarama yazilimlari sayesinde guclu analiz yapabilme kapasitesinin yani sira kolay uygulanabilirligi ve dusuk maliyetli olma ozelligi ile gercek zamanli HRM yontemi pek cok klinik uygulamada on plana cikmaktadir.