Exosomal αvβ6 integrin is required for monocyte M2 polarization in prostate cancer

Therapeutic approaches aimed at curing prostate cancer are only partially successful given the occurrence of highly metastatic resistant phenotypes that frequently develop in response to therapies. Recently, we have described αvβ6, a surface receptor of the integrin family as a novel therapeutic target for prostate cancer; this epithelial-specific molecule is an ideal target since, unlike other integrins, it is found in different types of cancer but not in normal tissues. We describe a novel αvβ6-mediated signaling pathway that has profound effects on the microenvironment. We show that αvβ6 is transferred from cancer cells to monocytes, including β6-null monocytes, by exosomes and that monocytes from prostate cancer patients, but not from healthy volunteers, express αvβ6. Cancer cell exosomes, purified via density gradients, promote M2 polarization, whereas αvβ6 down-regulation in exosomes inhibits M2 polarization in recipient monocytes. Also, as evaluated by our proteomic analysis, αvβ6 down-regulation causes a significant increase in donor cancer cells, and their exosomes, of two molecules that have a tumor suppressive role, STAT1 and MX1/2. Finally, using the Ptenpc−/− prostate cancer mouse model, which carries a prostate epithelial-specific Pten deletion, we demonstrate that αvβ6 inhibition in vivo causes up-regulation of STAT1 in cancer cells. Our results provide evidence of a novel mechanism that regulates M2 polarization and prostate cancer progression through transfer of αvβ6 from cancer cells to monocytes through exosomes

Modulation of paracrine interactions between prostate cancer cells and bone marrow stromal cells by transforming growth factor-beta signaling during colonization of bone

Sikes, Robert A.Prostate cancer (PCa) is the most prevalent cancer and the second leading cause of cancer related death for men in the United States. Death is primarily due to bone metastasis with more than 80% of men who die of PCa having bone involvement at autopsy. The complex bone microenvironment may initially resist the newly resident PCa cells but PCa cells acquire adaptive changes that allow them to survive and grow in the "hostile" new microenvironment as they co-evolve in their genotypic and phenotypic characters with bone cells. We have previously shown that soluble factors released from immortalized human bone marrow stromal cells (BMSC) induce apoptosis of PCa cells, and the surviving cells undergo neuroendocrine differentiation (NED), characterized by morphological changes consistent with a neuroendocrine phenotype. The presence of neuroendocrine tumor cells in PCa is associated with aggressiveness, resistance to hormonal therapy, and poor prognosis. Using the LNCaP progression model of increasingly metastatic and castrate-resistant prostate cancer (CRPC) cell lines, I examined the influence of BMSC factors on PCa survival, using the HS-5 and HS-27a BMSC lines, which were characterized previously for their ability to support different stages of hematopoiesis. Neuroendocrine markers were elevated in PCa cells surviving HS-5 BMSC conditioned medium (CM) treatment, while differentiation markers such as androgen receptor (AR) and prostate-specific antigen (PSA) were decreased. PCa cells that undergo NED using HS-5 BMSC CM or serum withdrawal had elevated phosphorylated-Smad2 levels. Furthermore, NED of PCa cells prevented HS-5 BMSC-induced apoptosis. Cell death induced by BMSC CM was analyzed using live/dead analysis while the effect on cell growth was examined in soft agarose colony formation assays in the presence and absence of intact TGF-Beta signaling. Using immunoblotting and luciferase reporter assays, I measured levels and activity of phosphorylated-Smad2 in PCa cells surviving treatment with HS-5 BMSC CM. Treatment of PCa cells with the ALK-4, 5, and 7 kinase inhibitor, SB-431542, resulted in a significant reduction in HS-5-mediated cell death. Correspondingly, pre-treatment of HS-5 BMSC with TGF-Beta1 yielded a CM that elicited a marked reduction in PCa cell death. The ancillary TGF-Beta receptor endoglin levels were also decreased upon TGF-Beta1 stimulation of HS-5 cells suggesting the importance of endoglin in mediating BMSC-induced PCa cell death. Small interfering RNA-mediated knockdown of endoglin in HS-5 cells verified that the effect on PCa cell death was a direct result of the attenuation of endoglin. Futhermore, the loss of the cytoplasmic domain of endoglin in HS-5 cells attenuated BMSC-induced PCa cell death indicating the importance of the cytoplasmic domain in maintaining endoglin function and expression of the factor(s) responsible for PCa cell death. Collectively, my findings indicate that 1) TGF-Beta signaling in PCa cells is induced during stimulation of NED, 2) TGF-Beta family cytokines secreted from HS-5 BMSC mediate PCa cell death, 3) TGF-Beta signaling in HS-5 BMSC alters paracrine signaling to promote PCa survival, 4) Endoglin is required for HS-5 BMSC-induced PCa cell death, 5) The cytoplasmic domain of endoglin is required for the expression of the factor(s) responsible for PCa cell death.University of Delaware, Department of Biological SciencesPh.D

The effects of group based cognitive behavioral therapy on self- compassion, social anxiety and ruminative thought style of turkish youth transitional age: a controlled study on university students

Objective: Social anxiety disorder (SAD), is characterized by the fear of being negatively evaluated or showing symptoms of anxiety in social environments or performance conditions which usually leads to avoidance behavior. It is known that changing negative thoughts and replacing them with alternatives have an important place in its treatment. In Cognitive Behavioral Therapy, the focus is mainly on the person's negative thoughts about himself. Group Based Cognitive Behavioral Therapy (CBGT) is a frequently used therapy model in anxiety disorders, including social anxiety. The aim of this study is to examine the effect of CBGT on the social anxiety levels of university students with elevated SAD symptoms, as well as on their ruminative thinking styles and self-compassion.Methods: Liebowitz Social Anxiety Scale (LSAS) was applied to 1200 students. Thirty students who had highest social anxiety levels were selected. The selected students were assigned to the experimental and placebo groups. CBGT was applied to the experimental group, and communication-based group therapy was applied to the placebo group.Results: There is a significant difference between pretest and posttest of the LSAS and rumination levels of the experimental group. In addition, LSAS and rumination post-test levels were found to differ significantly according to the group. There was no significant difference in self-compassion levels.

Abstract 4256: Neuroendocrine, stem, and stromal cell interactions involved in the organization of the normal colonic stem cell niche which become disorganized during colon tumorigenesis

Abstract In development of colorectal cancer (CRC), stem cell (SC) overpopulation underlies tumor initiation and progression, but it is incompletely understood which dysregulated mechanisms cause SC overpopulation. Because neuroendocrine cell (NEC) and SC populations both reside in the SC niche at the normal crypt bottom, we hypothesized that i) NECs play a role in maintaining the SC population, and ii) changes in the NEC population contributes to SC overpopulation and altered epithelial: stromal interactions during tumorigenesis. Immunofluorescence mapping and flow cytometry were used to analyze SC niche structure and cell-cell interactions in normal and neoplastic colonic tissues from Caucasian and African-American patients. In normal colonic crypts, most cells (77%) staining positively for the colonic SC marker ALDH1, also co-stained for the NE cell marker chromogranin-A (CGA). In the progression from normal to normal-appearing FAP to adenomatous to malignant colonic tissue, the proportion of ALDH1+/CGA+ cells progressively diminished while the proportion of ALDH1+/CGA- cells increased. The epithelial phenotype of tumor cells was confirmed by co-staining for pancytokeratin. These data suggest that colonic SC express a NE phenotype, and loss of this phenotype is associated with an increased number of SC during colon tumorigenesis. Our studies using flow cytometry and CRC cell lines (COLO320, DiFi, LIM1863, LoVo, SW480, HCT116 &amp; HT29) revealed that each line is characterized by the proportion of cells having a SC phenotype (ALDEFLUOR+) and NEC phenotype (SSTR+ or GLPR2+). have a low proportion. These findings suggest that these proportions are maintained constant through feedback mechanisms involving SC and NEC subpopulations. Our studies of epithelial-stromal interactions used immunofluorescence mapping of basement membrane proteins (Perlecan; collagen IV), inflammation markers (Cox2; Caveolin 1), pericryptal fibroblasts (smooth muscle actin), endothelial cells (CD34) and macrophages (CD68). Our results show that the stroma undergoes progressive disorganization (particularly pericryptal fibroblasts &amp; basement membrane) in parallel with increasing size of the SC population during colon tumorigenesis. These results suggest that genetic changes occurring during colon tumorigenesis lead to breakdown of stromal-epithelial interactions that are crucial to the maintenance of the stem cell niche, which contributes to colonic tissue disorganization that is a cardinal feature of cancer. Taken together, our investigations yield insights into: (i) the control of normal SC populations (including how the SC niche is maintained), (ii) molecular mechanisms underlying SC overpopulation in tumorigenesis, and (iii) potential targets for novel anti-cancer therapeutic strategies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4256.</jats:p

Enhancing filterability of activated sludge from landfill leachate treatment plant by applying electrical field ineffective on bacterial life

The aim of this study is to investigate filterability enhancement of activated sludge supplied form a full-scale leachate treatment plant by applying DC electric field while keeping the biological operational conditions in desirable range. The activated sludge samples were received from the nitrification tank in the leachate treatment plant of Istanbul's Odayeri Sanitary Landfill Site. Experimental sets were conducted as laboratory-scale batch studies and were duplicated for 1A, 2A, 3A, 4A, and 5A of electrical currents and 2, 5, 10, 15, and 30 min of exposure times under continuous aeration. Physicochemical parameters such as temperature, pH, and oxidation reduction potential in the mixture right after each experimental set and biochemical parameters such as chemical oxygen demand, total phosphorus, and ammonia nitrogen in supernatant were analyzed to define the sets that remain in the range of ideal biological operational conditions. Later on, sludge filterability properties such as capillary suction time, specific resistance to filtration, zeta potential, and particle size were measured for remaining harmless sets. Additionally, cost analyses were conducted in respect to energy and electrode consumptions. Application of 2A DC electric field and 15min exposure time was found to be the most favorable conditions to enhance filterability of the landfill leachate-activated sludge

The Turkish experience with therapeutic plasma exchange: A national survey

WOS: 000473249400014PubMed ID: 31036516Therapeutic plasma exchange (TPE) is used to treat more than 60 diseases worldwide and has drawn growing interest. Little is known about the current situation of TPE activity in Turkey, so we developed a survey to obtain information about this timely topic. We collected data on TPE from 28 apheresis units throughout Turkey. We performed a total of 24,912 TPE procedures with 3203 patients over the past decade. Twenty years ago, the majority of procedures were performed for neurological and hematological disorders, and today, most TPE procedures are done for the same reasons. The only historical change has been an increase in TPE procedures in renal conditions. Currently, renal conditions were more frequently an indication for TPE than rheumatic conditions. Fresh frozen plasma was the most frequently used replacement fluid, followed by 5% albumin, used in 57.9% and 34.6% of procedures, respectively. The most frequently used anticoagulants in TPE were ACD-A and heparin/ACD-A, used with 1671 (52.2%) and 1164 (36.4%) patients, respectively. The frequency of adverse events (AEs) was 12.6%. The most common AEs were hypocalcemia-related symptoms, hypotension, and urticaria. We encountered no severe AEs that led to severe morbidity and mortality. Overall, more than two thirds of the patients showed improvement in the underlying disease. Here, we report on a nationwide survey on TPE activity in Turkey. We conclude that there has been a great increase in apheresis science, and the number of TPE procedures conducted in Turkey has increased steadily over time. Finally, we would like to point out that our past experiences and published international guidelines were the most important tools in gaining expertise regarding TPE