Oleuropein modulates glioblastoma miRNA pattern different from Olea europaea leaf extract.

Glioblastoma (GBM) is the most prevalent and deadliest subtype of glioma. Despite current innovations in existing therapeutic modalities, GBM remains incurable, and alternative therapies are required. Previously, we demonstrated that Olea europaea leaf extract (OLE) kills GBM cells by modulating miR-181b, miR-137, miR-153 and Let-7d expression. However, although oleuropein (OL) is the main compound in OLE, its role in the antitumour effect of OLE remains unknown. This study determined the effect of OL on GBM cell line T98G and compared the results with our previous findings regarding the effect of OLE on the same cell line. The antiproliferative activity of OL and its effect on temozolomide (TMZ) response were tested inT98G cells using WST-1 assay. OL inhibition was evaluated using one-way analysis of variance with Tukey's post hoc test. The effect of OL on miR-181b, miR-137, miR-153 and Let-7d expression was assessed using quantitative reverse transcription polymerase chain reaction. Fold differences in expression between untreated, OL or OL + TMZ-treated samples were calculated using 2-ΔCt method. Significance was evaluated using an independent sample t-test. Treatment with 277.5 and 555 µM OL resulted in 39.51% and 75.40% reductions in T98G cells within 24 h. Coadministration of 325 µM TMZ and 277.5 or 555 µM, OL caused 2.08- and 2.83-fold increases, respectively, in the therapeutic effect of TMZ. OL + TMZ significantly increased microRNA expression, particularly Let-7d, than OLE. In conclusion, OL has an antitumour effect on GBM cells mainly via regulation of Let-7d expression. The present results also indicate other minor compounds in OLE play important anticancer roles.

Overexpression of miR-21 Is Associated With Recurrence in Patients With Hepatitis B Virus-Mediated Hepatocellular Carcinoma Undergoing Liver Transplantation.

Liver transplantation (LT) is the best treatment option for hepatitis B virus (HBV)-mediated hepatocellular carcinoma (HCC). Nevertheless, recurrence is the most important issue after LT. The aims of the present study were to evaluate the relation of dysregulated expression of microRNAs (miRNAs) in recurrence formation in HBV-mediated HCC cases. A total of 42 HBV-mediated HCC patients were evaluated in this study. Among 21 miRNAs, the expression level of miR-106a and miR-21 were higher and miR-143 and miR145 were lower in patients with HCC compared with noncancerous liver tissues (P = .0388, P = .0214, P = .0321, and P = .002, respectively). Compared with nonrecurrent patients, the expression level of miR-21 was 3.54-fold higher and miR-145 was 2.42-fold lower in patients with recurrence during the 5-year follow-up (P = .004 and P = .032; respectively). In addition, according to multivariate Cox regression analysis, the overexpression of miR-21 was found to be a prognostic indicator in HBV-mediated HCC patients (P = .002). In conclusion, we show a significant association between high expression of miR-21 and recurrence in HBV-mediated HCC. Therefore, up-regulation of miR-21 could serve as a promising prognostic marker for HCC.

The role of usnic acid-induced apoptosis and autophagy in hepatocellular carcinoma.

Usnic acid (UA) is a multifunctional bioactive lichen secondary metabolite with potential anti-cancer properties. Although the promising therapeutic effects of UA have been investigated in different cancer cell lines, the mechanism driving UA-induced cell death has yet to be elucidated. As the type of cell death (apoptosis or autophagy) induced by UA may vary depending on the cancer cell type, we first studied the cytotoxic effects of UA in HEPG2 (HBV(-)) and SNU-449(HBV(+)) hepatocellular carcinoma (HCC) cell lines. HCC cell viability was considerably reduced in a dose-dependent manner at 12, 24, and 48 h after treatment with UA ( p < 0.05). However, SNU-449 cells were more sensitive to UA than HEPG2 cells. UA also induced apoptotic cell death in HCC cells with cell cycle arrest at G0/G1 and G2/M phase depending on the genetic profile of each cell type. On the other hand, we observed acidic vesicular organelles in HCC cells after 36 h of UA treatment. Taken together, these findings suggest that UA stimulates apoptosis and autophagy in HEPG2 and SNU-449 cells without damaging normal control cells. Thus, UA might be a potential therapeutic compound for HCC treatment. However, there is a need for further studies investigating the death-promoting or preventing roles for autophagy and the molecular signaling mechanisms induced by UA treatment.

A novel [Mn2(µ-(C6H5)2CHCOO)2(bipy)4](bipy)(ClO4)2 complex loaded solid lipid nanoparticles: synthesis, characterization and in vitro cytotoxicity on MCF-7 breast cancer cells.

Manganese (Mn)-based complexes have been drawing attention due to the fact that they are more effective than other metal complexes. However, the use of Mn(II)-based complexes in medicine remains limited because of certain side effects. The aim of this study was to investigate the cytotoxic and apoptotic effects of a novel Mn(II) complex [Mn2(µ-(C6H5)2CHCOO)2(bipy)4](bipy)(ClO4)2 and Mn(II) complex loaded solid lipid nanoparticles (SLNs) on MCF-7 and HUVEC control cells. The average diameter of Mn(II) complex was about 1120 ± 2.43 nm, while the average particle size of Mn(II) complex-SLNs was ∼340 ± 2.27 nm. The cytotoxic effects of Mn(II) complex and Mn(II)-SLNs were 86.8 and 66.4%, respectively (p < .05). Additionally, both Mn(II) complex (39.25%) and Mn(II)-SLNs (38.05%) induced apoptosis and increased the arrest of G0/G1 phase. However, Mn(II) complex exerted toxic effects on the HUVEC control cell (63.4%), whereas no toxic effects was observed when treated with Mn(II)-SLNs at 150 µM. As a consequence, SLNs might be potentially used for metal-based complexes in the treatment of cancer due to reducing size and toxic effects of metal-based complexes.

Association of PALB2 sequence variants with the risk of early-onset breast cancer in patients from Turkey.

The PALB2 gene, has been accepted as a moderate-penetrance gene associated with breast cancer susceptibility and this gene product is involved in the DNA damage repair pathway via co-localization with BRCA2. Germline PALB2 mutations are associated with an increased breast cancer risk. However, the prevalence of the diverse types of PALB2 variants depend on the population. Thus, the aim of the present study was to determine, for the first time, the prevalence of PALB2 variants in a Turkish population of BRCA1/BRCA2-negative early-onset patients with breast cancer. In total, 223 Turkish patients with BRCA1/BRCA2 negative early-onset breast cancer and 60 unaffected women were included in the study. All the coding exons and intron/exon boundaries of PALB2 were subjected to mutational analysis by heteroduplex analysis (HDA)and DNA sequencing. Eighteen PALB2 variants were found in breast cancer patients within the Turkish population. Three variants (c.271G>A, c.404C>A and c.2981T>A) have not been previously reported. In addition, nine intronic variants were described, and this study is the first to describe the c.1685-44T>A intronic variant. The prevalence of possible pathogenic PALB2 variants was found to be 4.03 % in BRCA1/2-negative Turkish patients with early-onset breast cancer. Different variants of PALB2 have been reported in the literature, and the prevalence of these variants could different for each population. This is the first study to investigate the prevalence of PALB2 variants in Turkish patients with early-onset breast cancer.

Investigation of the genotoxic effect in bone marrow of Swiss albino mice exposed long-term to pyrimethamine.

In the present study, we investigated the genotoxic effect of pyrimethamine, which is a drug used in the therapy of toxoplasmosis and malaria, in bone marrow cells of Swiss albino mice exposed to three doses (1, 4, 8 mg/kg) of this agent for eight months orally in vivo. We used a chromosome analysis and micronucleus test for evaluation of genotoxic effect. While a statistically significant change was not determined in numerical chromosome abnormalities, structural chromosome aberrations and micronuclei were increased in a dose-dependent manner by cytogenetic and statistical evaluations.

Chromosomal fragile sites and relationship between genetic predisposition to small cell lung cancer.

Fragile sites are non-staining gaps and breaks on mammalian chromosomes. Several investigators have pointed out that these sites may act as factors that predispose to specific chromosomal rearrangements that are present in some cancer cases. The expression of common fragile sites induced by aphidicolin (Apc) was evaluated on prometaphase chromosomes obtained from the peripheral blood lymphocytes of 15 patients with lung cancer, 20 of their clinically healthy family members, and 20 age-matched normal controls. As a result of cytogenetic evaluation carried out by the High Resolution Banding (HRB) technique, 1q21, 2q33, 3p14, 7q32, 13q13, 16q23, 17q21, and 22q12 are defined as fragile sites in patients and relatives. The rate of total fragile sites and 2q33, 3p14, and 16q23 are statistically significant in both patients and relatives when compared with the control group. Therefore, our results showed that common fragile sites might be unstable factors in the human genome and they can be used as suitable markers for genetic predisposition to lung cancer.

Effects of Taxol plus radiation on the apoptotic and mitotic indices of mouse intestinal crypt cells.

PURPOSE: In this study we investigated the effect of Taxol, radiation, or Taxol plus radiation on highly proliferative normal tissue--the intestinal crypt cells of Swiss albino mice. MATERIALS AND METHODS: Swiss-albino mice, 3-4 months old, were used in this study. Taxol was administered by bolus intravenously through the tail vein. Radiation was given using a linear accelerator. There were four treatment categories, which comprised a total of 34 groups. Each group consisted of five animals. The first category was a control category which comprised one group (n = 5). The second treatment category was Taxol alone which comprised three groups (n = 15). The third treatment category was radiation alone which comprised three groups (n = 15). The fourth treatment category was Taxol plus radiation which comprised 27 groups (n = 135). Mice were killed 24 h after Taxol or radiation or combined administration using ether anesthesia. Using a light microscope, apoptotic and mitotic indices were counted on jejunal crypt cells of mice that were stained with hematoxylin-eosin. Differences between groups were statistically evaluated with Student's t-test. RESULTS: Taxol caused a dose-dependent increase in apoptosis (P = 0.045) and decreased the mitotic index (P = 0.006) at high doses. Similarly, radiation caused a dose-dependent increase in apoptosis (P = 0.046) and decreased the mitotic index (P = 0.299) at higher radiation doses. Compared to radiation alone, Taxol caused a significant induction of apoptosis (P = 0.010). In combination, no significant radiosensitizing effect of Taxol was observed (enhancement ratio < 1), when compared to radiation alone. However, an increase in apoptosis was observed after 24 h of Taxol exposure when compared to 12 or 48 h of Taxol exposure (P = 0.0001 and P = 0.0001). CONCLUSION: These findings suggest that Taxol did not cause a radiosensitizing effect in intestinal crypt cells. However, a 24-hour pretreatment of Taxol exposure followed by radiation caused significant induction of apoptosis and reduction of the mitotic index when compared to other Taxol timing sequences. Thus, the lack of a radiosensitizing effect of Taxol in these proliferative cells may be due to enhanced mitotic death rather than apoptotic death.

Genotoxic, hematoxic, pathological, and biochemical effects of hexane on Swiss albino rats.

In the present study, the genotoxic, hematoxic effects, and their relation with pathological and biochemical parameters of hexane were investigated. Cytogenetic evaluation performed on the bone marrow indicated that chromosome aberrations increased at both hexane doses in relation to the negative controls. Decreased hematocrit, hemoglobin concentrations, and mean corpuscular volume were observed on the whole blood counts. Conjugated dienes (CD), glutathione (GSH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and catalase (CAT) were increased. Histological examinations showed intracytoplasmic vacuolisation, nuclei with lower chromatin, and parenchymatous degenerations in the dose groups. In the bone marrow slides, depletion of the erythroid series were observed. In conclusion, hexane seems to be a genotoxic and hematoxic agent leading to degeneration and lipid peroxidation in exposed groups.

The relationship between genetic susceptibility to head and neck cancer with the expression of common fragile sites.

BACKGROUND: Numerous studies have recently been conducted to investigate genetic mechanisms in cancer causes and pathogenesis. Some of these studies have shown that there were certain specific chromosomal defects in normal cells of cancer patients and in their first-degree relatives. It was suggested that these individuals were susceptible to cancer development when compared with people without these defects. Materials and Methods Chromosomal anomalies, such as gaps, breaks, and acentric fragments, and fragile site expression rates were determined in peripheral blood lymphocyte cultures in 14 head and neck cancer patients, 17 first-degree relatives of these patients, and 20 healthy individuals as a control group in this study. RPMI 1640 medium, composed of aphidicolin, 5-bromodeoxyuridine, and caffeine were used for the induction of fragile sites. RESULTS: In cytogenetic and statistical evaluation, it was observed that both chromosomal aberration rates and fragile site expression frequencies in head and neck cancer patients and in their first-degree relatives were significantly greater than the control group (p <.05). It was found that fragile site expression was site specific in head and neck cancer patients and in their first-degree relatives. These specific sites were determined to be 1p21-22, 1q21, 1q25, 2q21, 2q31-33, 3p14, 16q22-23, 18q21, and 22q12 sites. CONCLUSIONS: These findings support studies showing that the fragile sites might be unstable factors in human genomes and their expression could be affected by some genetic factors, such as tumor suppressor genes and mismatch repair genes, and by some environmental factors, such as benzo (a) pyrene, dimethylnitrosamine, and dimethylsulfate. In conclusion, fragile sites may be playing an important role in the genetic tendency to head and neck cancer. Overexpression of these sites in normal lymphocytes may be used as a reliable marker to determine the genetic susceptibility in head and neck cancer patients and in their first-degree relatives.

Common fragile site expression and genetic predisposition to breast cancer.

The expression of common fragile sites induced by aphidicolin and caffeine was evaluated on prometaphase obtained from the peripheral blood lymphocytes of 35 women with breast cancer, their 35 clinically healthy female family members, and 20 sex- and age-matched normal controls. As a result of the cytogenetic and statistical evaluation, the number of damaged cells, chromosomal aberrations, and expression frequencies of fragile sites detected in patients with breast cancer and their first-degree relatives were found to be significantly higher than those in the control group. Our findings indicate an increased genetic instability in women with breast carcinomas and their relatives. Therefore, fragile sites may be used as a reliable marker for defining genetic susceptibility to cancer in general.