Kübra Açıkalın Coşkun

Synthesis and anticancer activity of acyl thioureas bearing pyrazole moiety.

In this work novel organic based compounds, acyl thiourea derivatives were synthesized and their anticancer activities were investigated. A new series of acyl thiourea derivatives containing pyrazole ring were prepared in good yield through one pot reaction of 4-benzoyl-1, 5-diphenyl-1H-pyrazole-3-carbonyl chloride with ammonium thiocyanate and various amines. The structures of the newly synthesized compounds were confirmed by IR, (1)H NMR, (13)C NMR and elemental analysis. Anticancer activities of synthesized compounds were evaluated on human colon, liver and leukemia cancer cell lines. Cell culture studies have demonstrated significant toxicity of the compounds on the cell lines, and the levels of toxicity have altered in the presence of various side groups. These results confirm that novel pyrazolyl acyl thioureas derived compounds may be utilized for cancer treatment. Furthermore, these compounds have a great potential and significance for further investigations.

Isolation and identification of free-living amoebae from tap water in Sivas, Turkey.

The present work focuses on a local survey of free-living amoebae (FLA) that cause opportunistic and nonopportunistic infections in humans. Determining the prevalence of FLA in water sources can shine a light on the need to prevent FLA related illnesses. A total of 150 samples of tap water were collected from six districts of Sivas province. The samples were filtered and seeded on nonnutrient agar containing Escherichia coli spread. Thirty-three (22%) out of 150 samples were found to be positive for FLA. The FLA were identified by morphology and by PCR using 18S rDNA gene. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of three different species, Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis. Naegleria fowleri, Balamuthia mandrillaris, or Sappinia sp. was not isolated during the study. All A. castellanii and A. polyphaga sequence types were found to be genotype T4 that contains most of the pathogenic Acanthamoeba strains. The results indicated the occurrence and distribution of FLA species in tap water in these localities of Sivas, Turkey. Furthermore, the presence of temperature tolerant Acanthamoeba genotype T4 in tap water in the region must be taken into account for health risks.

CO-releasing properties and anticancer activities of manganese complexes with imidazole/benzimidazole ligands

Abstract Carbon monoxide (CO) is an important signaling molecule which plays significant roles in the pathogenesis of cancer. CO is produced by enzymatic degradation of heme in mammals. Heme oxygenase 1 (HO-1) catalyzes the breakdown of heme into CO, ferrous iron, and biliverdin. CO induces HO-1 and inhibits cell proliferation. Cancer cells exposed to several stress factors (hypoxia, reactive oxygen species, cis-platin, and oxidative stress), and HO-1 displays cytoprotective role against oxidative stress and inhibits apoptosis, metastases, angiogenesis, and cell proliferation processes. Therefore, metal containing CO-releasing molecules (CORMs) have been designed as an effective cancer treatment strategy. CORMs are responsible for releasing controlled amounts of CO to cells and tissues. Thus, we synthesized [Mn(CO)3(bpy)L]X manganese containing CORMs [bpy = 2,2′-bipyridine, X = hexafluorophosphate (PF6), trifluoromethanesulfonate (OTf), L = imidazole, methylimidazole, benzimidazole, N-benzylbenzimidazole, N-(4-chlorobenzyl)benzimidazole] to release CO in human invasive ductal breast (MCF-7) cell line. In vitro experiments indicated that the compounds inhibited cell proliferation and exhibited cytotoxic effect on breast cancer cells. Moreover, side groups of the compounds enhanced the anticancer effects in MCF-7 cell line. These manganese containing CORMs gave promising results and may be used as a drug template for effective treatment of invasive ductal breast carcinoma.

Heat Shock Protein 40-Gok1 Isolation from Toxoplasma gondii RH Strain

Toxoplasma gondii is ubiquitous obligate intracellular parasite and is one of the most important pathogen for humans and animals. In humans, T. gondii has two life forms: tachyzoites and bradyzoites. Tachyzoites form of T. gondii can cause acute infection, and it is called toxoplasmosis. The development of latent bradyzoites from rapidly growing tachyzoites has been linked to cellular and environmental stresses which are associated with heat shock proteins (Hsps). Hsps play a protective role against stressors. Hsp40 is an important member of Hsp family and T. gondii has 36 predicted Hsp40 family members. Therefore, we studied the cloning and biochemical characterization of the T. gondii RH strain Hsp40 protein-Gok1. Hsp40 prevents protein aggregation and induce refolding. Consequently, Hsp40s may play essential roles in the mechanisms of bradyzoite development and survival in the host organism. Hsp40-Gok1 functional and structural properties may facilitate drug design and protein targeting against toxoplasmosis.

Anticancer activities of manganese-based photoactivatable CO-releasing complexes (PhotoCORMs) with benzimidazole derivative ligands

Carbon monoxide is an important signaling molecule which is produced by heme oxygenase-1. CO shows antiproliferative activity against cancer cells; hence, activation of HO-1 is a significant inhibition strategy against tumor formation and survival of cancer cells. In this work, manganese-based CO-releasing molecules (CORMs) were designed and synthesized to inhibit breast cancer cell proliferation. Human invasive ductal breast cancer cells (MCF-7) were treated with the synthesized CORMs to investigate the effect of the complexes on breast cancer survival under UV light. In vitro experiments indicated that the complexes inhibited breast cancer cell proliferation, and further, the antiproliferative effects were increased under UV light. Thus, these novel CORMs may provide a drug template for the treatment of invasive ductal breast cancer.

Isolation and characterization of Heat Shock Protein 100-Batu1 from Toxoplasma gondii RH strain

Toxoplasma gondii is an intracellular parasitic protozoon which infects human and most warm-blooded animals. Almost one-third of the worlds population is affected by life-threatening infection of T. gondii tachyzoites form. Slow growing, transmissible and encysted bradyzoites forms are composed after tachyzoites stage. Cellular and environmental stresses induce conversion of tachyzoites from bradyzoites and this condition is associated with Heat Shock Protein (Hsps) family. Hsp100 is a member of this protein family, and coordinates to disassemble protein aggregates with Hsp70 and Hsp40 in an ATP dependent manner. Several proteins are involved during this stage differentiation and Hsp100 may help them to be in their native soluble form to perform their function as observed in other organisms. For this purpose, Hsp100-Batu1 was isolated from T. gondii RH strain to characterize its biochemical properties in this current study. Hsp100 proteins play a role in survival and virulence of pathogens as shown in the literature. Therefore, manipulation of protein-protein interaction may perturb T. gondii infection and impair conversion to tachyzoites by inhibiting Hsp100 function. Therefore, results of this work present a potential route for vaccination or immunotherapy.

Hsp70 from Cyprinion macrostomus macrostomus and Garra rufa obtuse: Stability and stability-dependent activity

Two fish species, Cyprinion macrostomus macrostomus and Garra rufa obtuse, tolerate adverse conditions in the Kangal hot springs and cope with multiple stressors such as food deprivation, extreme temperature, toxins, protein degradation, hypoxia, and microbial damage. These fish have evolved strategies to counteract the stressors including the induction of heat shock proteins (Hsps). Hsps play an essential role in maintaining cellular homeostasis, and one of the key proteins in the mechanism is Hsp70. Hsp70 itself is exposed to the same stressors as all other proteins, and, hence, the stability of Hsp70 was investigated. For this purpose, Hsp70 ATPase activity was determined at different urea concentrations. It was found that the protein maintains considerable ATP hydrolysis activity at higher denaturant conditions. Temperature effects on the substrate peptide binding showed that Hsp70s bind prominently at elevated temperatures. Furthermore, temperature effects on Hsp70 aggregation indicated that the presence of nucleotides decreases the aggregation process. The present work has determined the stability and activity of cmHsp70 and grHsp70 themselves under extreme conditions. The stability of the Hsp70 proteins maintains substrate proteins in the native state, which may aid in the adaptation of the fish species to the hot spring environment.

Drug Dependent Stress and Heat ShockProtein Response

Stress induces radicals and this process triggers several biochemical pathways but most essential problem is the damage caused by the radicals on lipids, proteins, and nucleic acids. To perform biochemical functions, these macromolecules must be working properly. Proteins must be correctly folded so that they can regulate pathways and transmit signals. Under stress, alteration in cellular environment cause proteins to lose their structure. Then, the proteins either lose or alter their function. To scavenge radicals and to chaperone substrate proteins, a set of mechanic proteins are employed.