Benzalkonium chloride (BAK) induces apoptosis or necrosis, but has no major influence on the cell cycle of Jurkat cells

Benzalkonium chloride (BAK) is a cationic detergent with a very slow turnover. Because of its strong antibacterial activities, BAK is widely used especially in dentistry and ophthalmology. It is the most commonly used preservative in topical ophthalmic medications. Due to chronicity and widespread use of such treatments, BAK’s side effects are of great importance. BAK toxicity for adherent cells, probably related to its pro-oxidative activities, is time- and dose-dependent. Although lymphocytes often infiltrate superficial eye tissues, the BAK influence on them is yet to be established. The aim of this study was to check BAK cytotoxicity on T lymphocytic Jurkat line cells and to verify the suggestion that BAK can induce G2M cell blocks. A dose- and time-dependent cytotoxic effect of BAK on lymphoid cells in relatively low concentrations was shown in this study. In lower concentrations, it shows a moderate apoptotic and minimal antiproliferative effect on Jurkat cells, while in higher concentrations it shows a rapid necrotic effect. No G2M cell blocks were observed. Our findings could suggest lymphoid dysfunction during intensive, prolonged topical BAK treatment, even at dosages relatively non-toxic to epithelial eye cells. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 225–230

Application of primary cell cultures of laryngeal carcinoma and laser scanning cytometry in the evaluation of tumor reactivity to cisplatinum.

Unsatisfactory effects of treatment of laryngeal carcinoma patients stimulate the clinicians as well as researchers to develop new more effective treatment models and to find new reliable prognostic factors. The aim of the present study was the evaluation of the use of primary cell cultures of the laryngeal carcinoma and laser scanning cytometry (LSC) in the assessment of tumor reactivity to cisplatinum. Nineteen primary cultures of laryngeal carcinoma cells established from fragments of laryngeal carcinoma infiltrations were cultured with or without cisplatin, stained with monoclonal antibodies against P53 and BCL-2 proteins and analyzed by LSC. Cisplatin added to the culture medium leads to the significant increase of P53 expression and decrease of BCL-2 expression. Moreover, changes of P53 and BCL-2 expressions were significantly correlated. Our findings of apoptosis regulatory mechanisms could be useful in patient qualification for the chemotherapeutic follow-up treatment

The effect of Propionibacterium acnes on maturation of dendritic cells derived from acne patients' peripherial blood mononuclear cells.

Propionibacterium acnes (P. acnes) has been implicated in the pathogenesis of acne vulgaris which is the most common cutaneous disorder. It has a proinflammatory activity and takes part in immune reactions modulating the Th1/Th2 cellular response. The exposure of dendritic cells (DCs) to whole bacteria, their components, cytokines or other inflammatory stimuli and infectious agents induces differentiation from immature DCs into antigen-presenting mature DCs. The aim of the study was to evaluate the capability of P. acnes to induce the maturation of DCs. We stimulated monocyte derived dendritic cells (Mo-DCs) from acne patients with various concetrations of heat-killed P. acnes (10(6)-10(8) bacteria/ml) cultured from acne lesions. The results showed an increase in CD80+/CD86+/DR+ and CD83+/CD1a+/DR+ cells percentage depending on the concetration of P. acnes. The expression of CD83 and CD80 (shown as the mean fluorescence intensity - MFI) increased with higher concetrations of P. acnes. There were also significant correlations between MFI of CD83, CD80, CD86 and concetration of P. acnes. The study showed that P. acnes in the concetration of 10(8) bacteria/ml is most effective in the induction of Mo-DCs maturation. Futher studies concerning the influence on the function of T cells are needed

Application of primary cell cultures of laryngeal carcinoma and laser scanning cytometry in the evaluation of tumor reactivity to cisplatinum.

Unsatisfactory effects of treatment of laryngeal carcinoma patients stimulate the clinicians as well as researchers to develop new more effective treatment models and to find new reliable prognostic factors. The aim of the present study was the evaluation of the use of primary cell cultures of the laryngeal carcinoma and laser scanning cytometry (LSC) in the assessment of tumor reactivity to cisplatinum. Nineteen primary cultures of laryngeal carcinoma cells established from fragments of laryngeal carcinoma infiltrations were cultured with or without cisplatin, stained with monoclonal antibodies against P53 and BCL-2 proteins and analyzed by LSC. Cisplatin added to the culture medium leads to the significant increase of P53 expression and decrease of BCL-2 expression. Moreover, changes of P53 and BCL-2 expressions were significantly correlated. Our findings of apoptosis regulatory mechanisms could be useful in patient qualification for the chemotherapeutic follow-up treatment

T CD3+CD8+ Lymphocytes Are More Susceptible for Apoptosis in the First Trimester of Normal Human Pregnancy

Aims. Normal human pregnancy is a complex process of many immunoregulatory mechanisms which protect fetus from the activation of the maternal immune system. The aim of the study was to investigate the apoptosis of lymphocytes in peripheral blood of normal pregnant patients and healthy nonpregnant women. Methods. Sixty pregnant women and 17 nonpregnant women were included in the study. Lymphocytes were isolated and labeled with anti-CD3, anti-CD4, and anti-CD8 monoclonal antibodies. Apoptosis was detected by CMXRos staining and analyzed using the flow cytometric method. Results. We found significantly higher apoptosis of total lymphocytes in peripheral blood of pregnant patients when compared to healthy nonpregnant women. The percentage of apoptotic T CD3+CD8+ cells in the first trimester was significantly higher when compared to the third trimester of normal pregnancy. The ratio of T CD3+CD4+ : T CD3+CD8+ apoptotic lymphocytes was significantly lower in the first trimester when compared to other trimesters of pregnancy and to both of the phases of the menstrual cycle. Conclusions. The higher apoptosis of T CD3+CD8+ lymphocytes and the lower ratio of T CD3+CD4+ : T CD3+CD8+ apoptotic cells in the first trimester of normal pregnancy may suggest a higher susceptibility of T CD3+CD8+ cells for apoptosis as a protective mechanism at the early stage of pregnancy

Antiproliferative Activity of Melanoidins Isolated from Heated Potato Fiber (Potex) in Glioma Cell Culture Model

Potex constitutes a potato fiber preparation widely used as an ingredient to meat and bakery products which thermal treatment results in creation of new compounds. Melanoidins are high molecular weight brown end products of Maillard reaction, and few data presenting tumor cell growth inhibiting activity of melanoidins have been reported. Thus, in present study we utilized water extract of Potex roasted (180 degrees C for 2 h), whose chemical characterization revealed the presence of melanoidin complexes. Heated Potex extract inhibited C6 glioma cell proliferation in a dose-dependent manner measured by MTT method. High molecular weight components present in initial extract were responsible for stronger antiproliferative effect compared with low molecular weight fraction. Impaired MAPK (mitogen-activated protein kinase) and Akt signaling was found in cells treated with the extract. Moreover, flow cytometry analyses revealed the extract to induce G(1)/S arrest in glioma cells. Simultaneously, Western blot analysis showed elevated levels of p21 protein with concomitant decrease of cyclin D1. In conclusion, observed antiproliferative activity of melanoidins present in heated Potex was linked to disregulated MAPK and Akt signaling pathways, as well as to cell cycle cessation. These results suggest potential application of Potex preparation as a functional food ingredient and chemopreventive agent

Melanoidins isolated from heated potato fiber (Potex) affect human colon cancer cells growth via modulation of cell cycle and proliferation regulatory proteins

Melanoidins are brown, nitrogen containing, high molecular weight end products of Maillard reaction with poorly established activity towards tumor cells. The goal of present study was to verify whether both heated potato fiber Potex extract (180 degrees C for 2 h) and melanoidins isolated from the extract exerts growth-inhibiting activity in human colon cancer cells in vitro. The cells of LS180 colon cancer cell line were tested upon treatment with roasted potato fiber extract (AM4) as well as with high (HMW) and low (LMW) molecular weight fractions isolated from the extract, since both may be regarded as/or contain melanoidins. The tested compounds at concentration of 1000 mu g/ml reduced cell growth down to 45%, 69% and 54%, respectively. Furthermore, deregulated ERK1/2 signaling was revealed upon treatment. Moreover, multiple alternations in cell cycle regulators activity were found (i.e. cyclinD1, cyclin-dependent kinase 4 and 6, p21, p27, p53, pRb) leading to cell cycle cessation in GO phase. Importantly, LMW compounds revealed markedly stronger potential to alter specific molecular targets comparing to HMW compounds. Summarizing, the results emphasize that both high and low molecular weight melanoidins contribute to antiproliferative activity of heated potato fiber in LS180 colon cancer cells in vitro. (C) 2013 Elsevier Ltd. All rights reserved

Alpha-ketoglutarate (AKG) inhibits proliferation of colon adenocarcinoma cells in normoxic conditions

Background and objective. Alpha-ketoglutarate (AKG), a key intermediate in Krebs cycle, is an important biological compound involved in the formation of amino acids, nitrogen transport, and oxidation reactions. AKG is already commercially available as a dietary supplement and its supplementation with glutamine, arginine, or ornithine alpha-ketoglutarate has been recently considered to improve anticancer immune functions. It is well documented that AKG treatment of Hep3B hepatoma cells in hypoxia induced HIF-alpha (hypoxia-inducible factor) degradation and reduced vascular endothelial growth factor (VEGF) synthesis. Moreover, AKG showed potent antitumor effects in murine tumor xenograft model, inhibiting tumor growth, angiogenesis, and VEGF gene expression. However, the mechanisms of its anticancer activity in normoxia have not been examined so far. Results. Here, we report that in normoxia, AKG inhibited proliferation of colon adenocarcinoma cell lines: Caco-2, HT-29, and LS-180, representing different stages of colon carcinogenesis. Furthermore, AKG influenced the cell cycle, enhancing the expression of the inhibitors of cyclin-dependent kinases p21 Waf1/Cip1 and p27 Kip1. Moreover, expression of cyclin D1, required in G1/S transmission, was decreased, which accompanied with the significant increase in cell number in G1 phase. AKG affected also one the key cell cycle regulator, Rb, and reduced its activation status. Conclusion. In this study for the first time, the antiproliferative activity of AKG on colon adenocarcinoma Caco-2, HT-29, and LS-180 cells in normoxic conditions was revealed. Taking into consideration an anticancer activity both in hypoxic and normoxic conditions, AKG may be considered as a new potent chemopreventive agent