Hilal Kocdor

The effects of selenium against cerebral ischemia-reperfusion injury in rats

It is known that the brain tissue is extremely sensitive to ischemia-reperfusion (IR) injury and therefore, brain ischemia and consecutive reperfusion result in neural damage and apoptosis. The proinflammatory cytokines such as tumor necrosis factor alfa (TNF-alpha) and interleukin-1 beta (IL-1beta) are produced during neurological disorders including cerebral ischemia. On the other hand, nerve growth factor (NGF), which is essential for the differentiation, survival and functions of neuronal cells in the central nervous system, regulate neuronal development through cell survival and cell death signaling. In the present study, we aimed to investigate the effect of selenium (Se) on prefrontal cortex and hippocampal damage in rats subjected to cerebral IR injury. Selenium was injected intraperitoneally at the doses of 0.625 mg/(kg day) after induction of IR injury. Prefrontal cortex and hippocampal damage was examined by cresyl-violet staining. Apostain and caspase-3 immune staining were used to detect apoptosis. TNF-alpha, IL-1beta and NGF levels were also evaluated. Histopathological evaluation showed that treatment with selenium after ischemia significantly attenuated IR-induced neuronal death in prefrontal cortex and hippocampal CA1 regions of rats. Apoptotic cells stained with apostain and caspase-3 were significantly decreased in treatment group when compared with the IR group. Additionally, treatment with selenium decreased the TNF-alpha and IL-1beta levels and increased the NGF levels in prefrontal cortex and hippocampal tissue of animals subjected to IR. The present results suggest that selenium is potentially a beneficial agent in treating IR-induced brain injury in rats.

Human chorionic gonadotropin (hCG) prevents the transformed phenotypes induced by 17 β-estradiol in human breast epithelial cells.

Human chorionic gonadotropin (hCG), a hormone produced during pregnancy, can elicit life‐long refractoriness to carcinogenesis by differentiation of the breast epithelium. Human breast epithelial cells MCF‐10F form tubules in collagen, mimicking the normal ductules. We have shown that 17 β‐estradiol (E2) alter the ductulogenic pattern of these cells. The effect of the recombinant hCG (rhCG) in vitro was evaluated on the transformation of MCF‐10F induced by E2. MCF‐10F cells were treated with 70 nM E2 alone or in combination with 50 IU/ml rhCG during 2 weeks, while the controls were treated with DMSO (the solvent in which E2 was dissolved) or rhCG alone. At the end of treatment, the cells were plated in type I collagen matrix (3D‐cultures) for detecting 2 main phenotypes of cell transformation, namely the loss of ductulogenic capacity and the formation of solid masses. Although E2 significantly increased solid mass formation, this effect was prevented when MCF‐10F cells were treated with E2 in combination with rhCG. Furthermore, E2 increased the main duct width (p < 0.001), and caused a disruption of the luminal architecture, whereas rhCG increased the length of the tubules (p < 0.001) and produced tertiary branching. In conclusion, rhCG was able to abrogate the transforming abilities of estradiol, and had the differentiating property by increasing the branching of the tubules formed by breast epithelial cells in collagen. These results further support our hypothesis, known as the terminal differentiation hypothesis of breast cancer prevention, that predicts that hCG treatment results in protection from tumorigenic changes by the loss of susceptible stem cells 1 through a differentiation to refractory stem cells 2 and increase differentiation of the mammary gland.

The effects of pentoxifylline on bacterial translocation after intestinal obstruction.

Bacterial translocation (BT) occurs mainly in preseptic conditions such as intestinal obstruction, trauma, and burn, and the underlying mechanisms are still unclear. Pentoxifylline (PTX) is a derivative of methyl xanthine and has several beneficial effects in sepsis. We investigated the effects of PTX on a rat BT model. Simple intestinal obstruction (IO) was choosen to create high BT rates. Rats were divided in to five groups of 10 rats. Either 50 mg/kg PTX or placebo (3 mg/100 g saline) was administered subcutaneously following IO, either by single injection or twice with a 12-h interval. All rats were sacrificed 12 or 24 h after the procedure, and mesenteric lymph nodes (MLN), liver, and blood samples were obtained under aseptic conditions for bacterial cultures. The samples were obtained 12 h following IO in the first two groups, and the same samples were obtained 24 h after IO in last three groups. Groups IV and V were the PTX treatment groups. PTX was re-injected 12 h after IO only in group IV. As a result, BT rates in MLNs and liver were found to be significantly low, blood specimens remained sterile in PTX-pretreated and -treated rats, and BT rates were high in control groups and group V (once treatment late specimen group). We conclude that simple intestinal obstruction causes BT, and PTX reduces BT in rats with IO during the first 12-h period if PTX is given once immediately following IO. PTX reduces BT during the first 24-h after IO provided that is injected twice with a 12-h interval. More experimental studies are need to explain the exact mechanism of this beneficial effect.

Improvement of Colonic Healing by Preoperative Rectal Irrigation With Short-Chain Fatty Acids in Rats Given Radiotherapy

BACKGROUNDWe investigated the effect of preoperative rectal irrigation with short-chain fatty acids on irradiated colonic anastomosis in rats.METHODSSixty male Wistar rats were divided into four groups. Group I (control group, n = 15) underwent left colon resection and primary anastomosis. Group II (Short-chain fatty acids pretreatment group, n = 15) had short-chain fatty acids rectal irrigation for five days preoperatively. Group III (preoperative radiotherapy group, n = 15) underwent irradiation to the whole pelvis eight and four days before the operation, for a total dose of 20 Gy. Group IV (preoperative radiotherapy group + short-chain fatty acids pretreatment group, n = 15) had rectal irrigation with short-chain fatty acids for five days after the second irradiation. Within each group, animals were anesthetized to assess the clinical, mechanical, histologic, and biochemical parameters of anastomotic healing on either the third or seventh postoperative days.RESULTSThe mean bursting pressure was significantly low in Group III on Day 3 and was significantly high in Group IV on Day 7 (P = 0.001, P = 0.021). The burst occurred at the anastomoses in all animals tested on the third postoperative day, and outside of the anastomoses in all animals tested on the seventh postoperative day. The histologic parameters of anastomotic healing, such as epithelial regeneration and formation of granulation tissue, were significantly improved by use of preoperative rectal irrigation with short-chain fatty acids on Day 7. The amount of total and salt-soluble collagen concentrations significantly increased in Group IV compared with the control group on Day 3 (P = 0.008, P = 0.004).CONCLUSIONSome mechanical and histologic aspects of colonic anastomotic healing can be adversely affected by preoperative radiotherapy, but rectal irrigation with short-chain fatty acids may improve anastomotic healing.

Irisin immunohistochemistry in gastrointestinal system cancers

Cancer is the leading cause of morbidity and mortality worldwide. Some studies have shown that high heat kills cancer cells. Irisin is a protein involved in heat production by converting white into brown adipose tissue, but there is no information about how its expression changes in cancerous tissues. We used irisin antibody immunohistochemistry to investigate changes in irisin expression in gastrointestinal cancers compared to normal tissues. Irisin was found in human brain neuroglial cells, esophageal epithelial cells, esophageal epidermoid carcinoma, esophageal adenocarcinoma and neuroendocrine esophageal carcinoma, gastric glands, gastric adenosquamous carcinoma, gastric neuroendocrine carcinoma, gastric signet ring cell carcinoma, neutrophils in vascular tissues, intestinal glands of colon, colon adenocarcinoma, mucinous colon adenocarcinoma, hepatocytes, hepatocellular carcinoma, islets of Langerhans, exocrine pancreas, acinar cells and interlobular and interlobular ducts of normal pancreas, pancreatic ductal adenocarcinoma, and intra- and interlobular ducts of cancerous pancreatic tissue. Histoscores (area × intensity) indicated that irisin was increased significantly in gastrointestinal cancer tissues, except liver cancers. Our findings suggest that the relation of irisin to cancer warrants further investigation.

Toxicity Induced by he Chemical Carcinogen 7,12-Dimethylbenz[a]anthracene and the Protective Effects of Selenium in Wistar Rats

7,12-Dimethylbenz[a]anthracene (DMBA), a polycyclic aromatic hydrocarbon (PAH), has been used extensively as a tool to initiate mammary carcinogenesis and subsequent chemoprevention. On the other hand, selenium (Se) is potentially useful in oncology because this element possesses anticarcinogenic and chemopreventive properties. Se-containing enzymes such as glutathione peroxidase (GPx) play an important role in PAH metabolism and detoxification. In this study, rats were administered a single, oral dose of DMBA (12 mg). In the Se group, rats received 20 µg Se daily via gavage, starting 2 wk before the DMBA administration and continued for 1 wk. One hundred twenty days after DMBA administration the rats were sacrificed and toxicity was evaluated using histopathological and biochemical criteria. Five rats (30%) died in the DMBA group within the study period, whereas no death occurred in the DMBA–Se-treated group. Malignant tumor frequency was 33% in the DMBA group, while no malignant tumors occurred in the DMBA–Se-treated group. Some inflammatory changes rather than epithelial changes were found upon histopathological examination. GPx activity and blood urea nitrogen levels were higher and kidney GST activity was lower in the DMBA–Se-treated group compared to DMBA alone. In conclusion, Se appears to be effective in preventing some of the adverse effects associated with DMBA. This research has been partially carried out at Dokuz Eylul University School of Medicine, Learning Resources Center Research Laboratory (ARLAB). The authors thank Dr. Ali Riza Sisman for his kind contributions and Prof. Dr. Gul Guner and Dr. Sam Kacew for their helpful advice.

Zinc supplementation induces apoptosis and enhances antitumor efficacy of docetaxel in non-small-cell lung cancer

Background Exposure to exogenous zinc results in increased apoptosis, growth inhibition, and altered oxidative stress in cancer cells. Previous studies also suggested that zinc sensitizes some cancer cells to cytotoxic agents depending on the p53 status. Therefore, zinc supplementation may show anticancer efficacy solely and may increase docetaxel-induced cytotoxicity in non-small-cell lung cancer cells. Methods Here, we report the effects of several concentrations of zinc combined with docetaxel on p53-wild-type (A549) and p53-null (H1299) cells. We evaluated cellular viability, apoptosis, and cell cycle progression as well as oxidative stress parameters, including superoxide dismutase, glutathione peroxidase, and malondialdehyde levels. Results Zinc reduced the viability of A549 cells and increased the apoptotic response in both cell lines in a dose-dependent manner. Zinc also amplified the docetaxel effects and reduced its inhibitory concentration 50 (IC50) values. The superoxide dismutase levels increased in all treatment groups; however, glutathione peroxidase was slightly increased in the combination treatments. Zinc also caused malondialdehyde elevations at 50 μM and 100 μM. Conclusion Zinc has anticancer efficacy against non-small-cell lung cancer cells in the presence of functionally active p53 and enhances docetaxel efficacy in both p53-wild-type and p53-deficient cancer cells.

Progressive increase of glucose transporter-3 (GLUT-3) expression in estrogen-induced breast carcinogenesis

IntroductionIncreased glucose uptake and glycolysis are main metabolic characteristics of malignant cells. A family of glucose transporters (GLUTs) facilitates glucose movement across the plasma membranes in a tumor-specific manner. Glucose transporter-1 (GLUT-1), GLUT-3 and recently GLUT-12, have been previously shown in breast cancer cells and are found to be associated with poor prognosis. In addition, it has been shown that estrogen plays critical roles in GLUT regulation, however, the stage-specific GLUT regulation of mammary carcinogenesis is unclear.MethodsGLUT expression patterns were investigated in an in vitro–in vivo progressive, estrogen-induced, mammary carcinogenesis model which consisted of four cell lines, with same genetic background. In this model, different stages of tumor initiation and progression are represented, MCF-10F being the normal stage, E2 cells the transformed stage by estrogen, C5 cells, the invasive stage, and T4 cells the tumorigenic stage. In addition, loss of ductulogenesis and solid mass formation in collagen matrix and invasiveness of the cells were counted.ResultsReal time PCR showed that GLUT1 expression was downregulated in MCF10F after treatment with 17β-estradiol (E2), and in the invasive cell type (C5), but not in the tumor cells (T4), which had no changes compared to MCF10F. C5 and T4 cells showed the highest rate of GLUT-3 expression. These cells were also found to be associated with loss of ductulogenesis, solid mass formation and higher invasive capacity, whereas, GLUT-12 was downregulated in C5 and T4 cells.ConclusionEstrogen-induced malignant transformation is associated with remarkable and progressive GLUT-3 expression, GLUT-1 re-expression at further stages, as well as GLUT-12 downregulation.

Ghrelin expression of endometrium hyperplasia and endometrioid carcinoma.

Background. Endometrium carcinoma ranks fourth among female carcinomas. Therefore, early diagnosis of endometrium pre-malignant lesions is emphasised, and attempts are made to identify the risk factors. Since hyperplasias, particularly those with atypia, are held responsible for the development of the most common endometrium carcinomas, it is important to definitely distinguish between well-differentiated carcinomas and hyperplasia with atypia. In the present study, we aimed to explore whether ghrelin expression had a role in distinguishing between benign, pre-malignant and malignant lesions of endometrium. Methods. Tissue ghrelin expressions of a total of 60 cases, who were diagnosed in the Pathology Department Laboratory of Fırat University Medical School, and of whom 10 were in the proliferation phase, 10 had simple hyperplasia without atypia, 10 had simple hyperplasia with atypia, 10 had complex hyperplasia without atypia, 10 had complex hyperplasia with atypia and 10 had endometrioid carcinoma cases, were examined using immunohistochemical method. Additionally, tissue samples were homogenised to analyse tissue ghrelin levels in the supernatants according to RIA method. Samples from the parotid glands were used as positive control for ghrelin. Cells that exhibited cytoplasmic staining with ghrelin antibody were evaluated as positive. Results. Immunohistochemical examination showed that ghrelin expression increased markedly in the proliferation phase, relative to hyperplasias and carcinoma. These results were parallel to ghrelin levels in tissue supernatants. Immunohistochemical and RIA analysis results indicate that ghrelin expression either markedly decreases or is entirely depleted in endometrial carcinomas. Conclusions. Therefore, we think that ghrelin expression can be useful in differentiating not only endometrium carcinomas from benign lesions but also complex hyperplasias with atypia, which pose diagnostic difficulties.

Effects of Locally Applied 5-Fluorouracil on the Prevention of Postmastectomy Seromas in a Rat Model

Backgrounds: Seroma formation is the most common complication following mastectomy and axillary dissection (AD). Currently available interventions have aimed at obliterating dead space by inducing fibrosis and through various mechanical methods. Here, 5-fluorouracil (5-FU), used as a sclerosing agent for the prevention of seroma formation, was investigated in a rat mastectomy model. Methods: 20 rats were divided into two groups (5-FU and control). All rats underwent mastectomy and AD. Immediately following the operation, equal volumes of saline and 5-FU were administered under the surgical flaps. One week after the operation, seroma formation and wound-healing processes were evaluated using histopathological and biochemical investigations. Results: 5-FU did not act as a sclerosing agent, yet it was highly effective in preventing seroma formation. The intensity of acute inflammation, vascularity, as well as leukocyte and fibroblast infiltration, were significantly lower in the 5-FU group than the control; the tissue collagen fractions and total seroma collagen contents were found to be similar between the two groups. Conclusions: The mechanisms underlying seroma prevention by 5-FU are probably related to a decrease in the inflammation and angiogenesis rather than a local fibrotic process. Seroma formation may be due to a prolonged inflammatory phase of wound healing.