Hülya Sivas

Quercetin and Cisplatin combined treatment altered cell cycle and mitogen activated protein kinase expressions in malignant mesotelioma cells

BackgroundMalignant mesothelioma is a locally aggressive and highly lethal neoplasm of pleural, peritoneal and pericardial mesothelial cells without successful therapy. Previously, we reported that Quercetin in combination with Cisplatin inhibits cell proliferation and activates caspase-9 and -3 enzymes in different malignant mesothelioma cell lines. Moreover, Quercetin + Cisplatin lead to accumulation of both SPC111 and SPC212 cell lines in S phase.MethodsIn present work, 84 genes involved in cell growth and proliferation have analysed by using RT2-PCR array system and protein profile of mitogen activated protein kinase (MAPK) family proteins investigated by western blots.ResultsOur results showed that Quercetin and Quercetin + Cisplatin modulated gene expression of cyclins, cyclin dependent kinases and cyclin dependent kinases inhibitors. In addition genes involved in JNK, p38 and MAPK/ERK pathways were up regulated. Moreover, while p38 and JNK phosphorylations were increased, ERK phosphorylations were decreased after using Quercetin + Cisplatin.ConclusionThis research has clarified our previous results and detailed mechanism of anti-carcinogenic potential of Quercetin alone and incombination with Cisplatin on malignant mesothelioma cells.

Novel nanoimaging approach: Antibodious polymeric nanolabel for intracellular alpha‐fetoprotein targeted monitoring

This study describes preparation and use of novel labeled and antibodious polymeric nanolabels (anti‐alpha fetoprotein cross‐linked nanolabels) as an immunogenic and semisynthetic nanolabel with potential prognostic and therapeutic roles for hepatoma cancer. Specificity, uptake, and binding efficiencies of the nanolabel have been examined in a human hepatosarcoma cell line HepG2, a human colorectal cell line DLD‐1, and a mouse myoblast cell line C2. Labeling of the cells has been performed by treating live and fixed cells with varying concentrations of the nanolabels and then, the cells have been examined under a fluorescence microscope. In addition, all cell lines have also been labeled using FITC‐conjugated nanotrastuzumab to compare the results obtained with those of the binding of the FITC‐nanoanti‐alpha fetoprotein nanolabels. Results show that FITC‐conjugated anti‐alpha fetoprotein cross‐linked nanolabels have been taken up by both live and fixed cells and have efficiently and specifically labeled HepG2 cells at a quite low concentration. Taken all together, the results indicate that the novel targeted nanoimaging tools and technique demonstrated their ability to detect the distribution of the nanolabels as probes in hepatoma cells.

Investigation of genotoxic effects of paraben in cultured human lymphocytes

Abstract Paraben is a phenolic derivative of benzoic acid extensively used as preservatives in food, pharmaceutical, and cosmetic industries due to its antimicrobial characteristics. The objective of this study was to evaluate the in vitro genotoxic effects of paraben in human lymphocyte cultures. Cells were analyzed by cytokinesis-block micronucleus (CBMN), chromosome aberration (CA), sister chromatid exchange (SCE), and comet tests. For CBMN, CA, and SCE assays, the human lymphocytes were isolated from healthy donors and incubated with 500, 250, 100, and 50 µg/mL of paraben for 24 and 48 h, and for comet assay, cells were exposed to 1000, 750, 500, and 250 µg/mL of paraben for an hour. Results showed that numbers of MN and SCEs were not significant in the cells exposed to paraben when compared to the solvent control. However, 500 and 250 µg/mL of paraben induced the CA after 24 h. Also, we observed a significant decrease in the cytokinesis-block proliferation index in cells exposed 250–500 µg/mL paraben for 24 h, and 100, 250, and 500 µg/mL for 48 h. The mitotic index was also decreased at all concentrations and periods. However, the proliferation index was statistically decreased at all concentrations after 48 h treatments. Only the highest concentration of paraben caused DNA migration (mean tail length) in human lymphocytes analyzed by Comet assay. Taken together, results indicated that paraben had cytotoxic effects and caused genotoxicity by affecting directly chromosomes and DNA in human lymphocyte cells in vitro, and may have genotoxic potential for human.

Antigenotoxic Effect of Some Lichen Metabolites

Naturally occurring compounds can have protective effects towards mutagens and carcinogens, as shown by numerous studies. Several lichen species have been given much attention by researchers because their extracts and compounds have been used in traditional medicine to cure diseases such as ulcer, arthritis, tuberculosis, and cancer throughout the ages. Although a wide variety of scientific investigations on the biological activities of lichen extracts and their constituents have been performed, there is rather less research on their genotoxicity and antigenotoxic activity. To date, most results for the genotoxic/antigenotoxic activities of lichens have been obtained for lichen extracts and their constituents using the Ames/Salmonella and the E. coli WP2 microsome, chromosome aberration, micronucleus, sister chromatid exchange, single-cell gel electrophoresis, 8-OH-dG activity, and wing somatic mutation and recombination assays. In the present chapter, findings on antigenotoxic/genotoxic activities and its mechanisms are evaluated. By using the most common bacterial and nonbacterial assays, extracts of various lichen species have been shown to have promising antigenotoxic activity with somewhat less genotoxic activity. Lichen extracts may have a possible therapeutic potential. Therefore, these extracts must be further investigated by other multiple in vitro bioassays for development of therapeutic agents.

Identification of biomarkers associated with partial epithelial to mesenchymal transition in the secretome of slug over-expressing hepatocellular carcinoma cells.

BackgroundHepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. Complete epithelial to mesenchymal transition (EMT) has long been considered as a crucial step for metastasis initiation. It has, however, become apparent that many carcinoma cells can metastasize without complete loss of epithelial traits or with incomplete gain of mesenchymal traits, i.e., partial EMT. Here, we aimed to determine the similarities and differences between complete and partial EMT through over-expression of the EMT-associated transcription factor Slug in different HCC-derived cell lines.MethodsSlug over-expressing HCC-derived HepG2 and Huh7 cells were assessed for their EMT, chemo-resistance and stemness features using Western blotting, qRT-PCR, neutral red uptake, doxorubicin accumulation and scratch wound healing assays. We also collected conditioned media from Slug over-expressing HCC cells and analyzed its exosomal protein content for the presence of chemo-resistance and partial EMT markers using MALDI-TOF/TOF and ELISA assays, respectively.ResultsWe found that Slug over-expression resulted in the induction of both complete and partial EMT in the different HCC-derived cell lines tested. Complete EMT was characterized by downregulation of E-cadherin and upregulation of ZEB2. Partial EMT was characterized by upregulation of E-cadherin and downregulation of vimentin and ZEB2. Interestingly, we found that Slug induced chemo-resistance through downregulation of the ATP binding cassette (ABC) transporter ABCB1 and upregulation of the ABC transporter ABCG2, as well as through expression of CD133, a stemness marker that exhibited a similar expression pattern in cells with either a complete or a partial EMT phenotype. In addition, we found that Slug-mediated partial EMT was associated with enhanced exosomal secretion of post-translationally modified fibronectin 1 (FN1), collagen type II alpha 1 (COL2A1) and native fibrinogen gamma chain (FGG).ConclusionsFrom our data we conclude that the exosomal proteins identified may be considered as potential non-invasive biomarkers for chemo-resistance and partial EMT in HCC.