[Cold atmospheric plasma for the treatment of urological tumors]

Cold atmospheric plasma (CAP) is a highly reactive ionized physical state consisting of electrically charged particles, radicals and photons as well as electromagnetic radiation. Due to the high energy and reactivity of plasma components, physical plasmas are also referred to as the 4th aggregate state. In biological systems, CAP promotes antimicrobial, immunomodulatory, anti-inflammatory, and wound-healing effects. Moreover, CAP bears antineoplastic properties which may be applied as a potential intraoperative option in the treatment of wound and resection margins during surgery of urological tumors. Some properties such as the penetration depth in various biological tissues, the effect on physiological healthy tissue, and the molecular mode of action regarding signalling and effector pathways are the subject of further investigation. CAP treatment effectively attenuates malignant cell growth. As an intraoperative application, CAP may represent a promising option particularly for the treatment of tissue regions that are close to critical structures (e. g., nerves, adjacent organs). The present review article summarizes the current status of CAP-related studies in the field of urological oncology.

[Influence of culture and religion on the treatment of cancer patients]

Religion, which is one of the most important sources of human identity, has so far hardly been taken into account in the clinic. In the largely secularized society of Germany, this has played a highly subordinate role. Currently, however, the development towards a multireligious society is emerging, which will also be reflected in everyday medical care. Disease and mortality in patients can affect different cultural-religious spheres. Although distinction between cultural and religious aspects is possible, it is not necessary for clinical practice. In the situation of oncological therapy, questions may arise which must be answered differently in the religions Christianity, Judaism and Islam and which should be taken into account when selecting therapy. The consideration of cultural-religious rules can intensify the patient's acceptance, but it can also impair it in case of disregard. Such peculiarities can be the separation into male and female spheres or the restriction of certain auxiliary substances or drugs (blood products, narcotics). Kübler-Ross's phase model is suitable for determining where cultural-religious sensitivities should be taken into account in the phases of disease and how cultural-religious offerings can benefit the course of therapy. Due to large individual, regional, cultural and confessional differences, no systematic catalogue of procedures can be provided here. However, knowledge of such differences, more sensitive interaction with patients and their families and cooperation with hospital pastors can strengthen the relationship of trust between doctor and patient and thus improve the conditions for successful oncological therapy. These aspects should not be underestimated when treating people of other faiths in Germany's secular society.

Dirty deeds done dirt cheap: sensitization of prostate cancer cells to abiraterone treatment using hydroxylated polychlorinated biphenyls

Effective targeting of androgen biosynthesis by the 17α-hydroxylase/17,20-lyase inhibitor abiraterone prolongs survival in a variety of prostate cancer patients. However, resistance to abiraterone treatment occurs frequently and the development of new drugs supporting or complementing abiraterone therapy is urgently needed. We recently reported antiproliferative and proapoptotic effects of hydroxylated polychlorinated biphenyls (PCBs) on various blood cell lines in vitro. Here we report the biological evaluation of the PCB28 derived OH-metabolites 3-OHCB28 or 3'-OHCB28 in prostate cancer cells. Depending on concentration, both metabolites inhibit the growth of PC3 cells, a cell line representing later stages of advanced prostate cancer. In addition 3'-OHCB28 reduced the necessary concentration of abiraterone required for the inhibition of PC3 cells by a factor of 4. Western blot analysis of cytoprotective heatshock proteins (HSP) implicated a significant reduction of HSP27 expression by 3'-OHCB28 in PC3 cells. Given the known HSP27 suppressive role of abiraterone, our results therefore suggest, that that the pharmacological interaction between abiraterone and 3'-OHCB28 in PC3 cells could be produced by the combined effect of both substances on the expression of HSPs, especially the expression of HSP27. Including the known dose response linkages and pharmacokinetic characteristics of the OH-metabolites described here, we conclude, that the use of hydroxylated PCBs can be supportive for the anti-proliferative treatment of prostate cancer and merits further investigation.

The androgen receptor antagonist enzalutamide induces apoptosis, dysregulates the heat shock protein system, and diminishes the androgen receptor and estrogen receptor β1 expression in prostate cancer cells

Enzalutamide's accepted mode of action is by targeting the androgen receptor's (AR) activity. In clinical practice, enzalutamide demonstrates a good benefit-risk profile for the treatment of advanced prostate cancer (PC), even after poor response to standard antihormonal treatment. However, since both, well-established antiandrogens and enzalutamide, target AR functionality, we hypothesized that additional unknown mechanisms might be responsible for enzalutamide's superior anticancer activity. In the current study, PC cells were incubated with enzalutamide and enzalutamide-dependent modulation of apoptotic mechanisms were assessed via Western blot analysis, TDT-mediated dUTP-biotin nick end-labeling assay, and nuclear morphology assay. Alterations of heat shock protein (HSP), AR, and estrogen receptor (ER) expression were examined by Western blot analysis. Enzalutamide attenuated the proliferation of PC cells in a time- and dose-dependent manner. In the presence of enzalutamide, apoptosis occurred which was shown by increased BAX expression, decreased Bcl-2 expression, nuclear pyknosis, and genomic DNA fragmentation. Moreover, enzalutamide inhibited the expression of HSPs primarily involved in steroid receptor stabilization and suppressed AR and ERβ1 expression. This study demonstrates for the first time that enzalutamide treatment of PC cells triggers varying molecular mechanisms resulting in antiproliferative effects of the drug. In addition to the well-characterized antagonistic inhibition of AR functionality, we have shown that enzalutamide also affects the intracellular synthesis of steroid receptor-associated HSPs, thereby diminishing the expression of AR and ERβ1 proteins and inducing apoptotic pathways. According to an indirect attenuation of HSP-associated factors such as steroid receptors, endometrial carcinoma, uterine leiomyosarcoma, and mamma carcinoma cells also demonstrated inhibited cell growth in the presence of enzalutamide. Our data, therefore, suggest that enzalutamide's high efficacy is at least partially independent of AR and p53 protein expression, which are frequently lost in advanced PC.

The heat shock protein 70 inhibitor VER155008 suppresses the expression of HSP27, HOP and HSP90β and the androgen receptor, induces apoptosis, and attenuates prostate cancer cell growth

Heat shock proteins (HSPs) are molecular chaperones that play a pivotal role in correct folding, stabilization and intracellular transport of many client proteins including those involved in oncogenesis. HSP70, which is frequently overexpressed in prostate cancer (PCa), has been shown to critically contribute to tumor cell survival, and might therefore represent a potential therapeutic target. We treated both the androgen receptor (AR)-positive LNCaP and the AR-negative PC-3 cell lines with the pharmacologic HSP70 inhibitor VER155008. Although we observed antiproliferative effects and induction of apoptosis upon HSP70 inhibition, the apoptotic effect was more pronounced in AR-positive LNCaP cells. In addition, VER155008 treatment induced G1 cell cycle arrest in LNCaP cells and decreased AR expression. Further analysis of the HSP system by Western blot analysis revealed that expression of HSP27, HOP and HSP90β was significantly inhibited by VER155008 treatment, whereas the HSP40, HSP60, and HSP90α expression remained unchanged. Taken together, VER155008 might serve as a novel therapeutic option in PCa patients independent of the AR expression status.

Dose-Dependent Tissue-Level Characterization of a Medical Atmospheric Pressure Argon Plasma Jet

Nonthermal treatment with cold atmospheric plasma (CAP) is a promising option for local treatment of chronic-inflammatory and precancerous lesions as well as various mucosal cancer diseases, besides its primary indication for wound healing and antiseptics. Atmospheric pressure plasma jets (APPJs) are versatile plasma sources, some of which are well-characterized and medically approved. The characterization of APPJs, however, is often based on the treatment of simple solutions or even studies on the plasma effluent itself. To better assess the in vivo effects of CAP treatment, this study aims to recapitulate and study the physicochemical tissue-level effects of APPJ treatment on human primary mucosal tissue and tissue models. High resolution on-tissue infrared (IR) thermography and a first-time-performed spatially resolved optical emission spectroscopy (OES) of the APPJ emissions did not identify potentially tissue-harming effects. In this study, electron-spin-resonance (ESR) spectroscopy on human tissue samples, treated with different CAP doses, enabled the measurement and the distribution of CAP-derived radicals in the tissues. The results correlate plasma dosage and the generation of radical species with cell viability and cell proliferation of primary human fibroblasts while demonstrating apoptosis-independent antiproliferative cell effects. Moreover, a dose-dependent increase of cells in the G1 phase of the cell cycle was observed, stressing the likely important role of cell cycle regulation for antiproliferative CAP mechanisms. This study introduces suitable methods for CAP monitoring on tissues and contributes to a better understanding of tissue-derived plasma effects of APPJs.

Overexpression of MicroRNA-1 in Prostate Cancer Cells Modulates the Blood Vessel System of an In Vivo Hen's Egg Test-Chorioallantoic Membrane Model

BACKGROUND/AIM

In prostate cancer (PC), the formation of new blood vessels is stimulated by hypoxic conditions, androgens, and a number of molecular factors including microRNAs. MicroRNA-1 (miR-1) has been characterized in some tumor entities as anti-angiogenic, but this has not yet been investigated in PC.

MATERIALS AND METHODS

PC cells stably overexpressing miR-1 (LNCaP-miR-1) were incubated on an in vivo hen's egg test-chorioallantoic membrane (HET-CAM) model and compared to maternal LNCaP cells. Cell growth, blood vessel organisation, and total blood vessel area were analysed.

RESULTS

Both matrigel-embedded LNCaP and LNCaP-miR-1 cells formed compact tumor-like cell aggregates on the CAM of the HET-CAM model. Although not quantifiable, bleeding of the CAM and remodelling of the blood vessel network in the CAM indicated an influence of miR-1 on the vascular system. The statistically significant decrease in the total surface area of blood vessels in the visible CAM section to 79.4% of control cells demonstrated the antiangiogenic properties of miR-1 for the first time.

CONCLUSION

MiR-1 had a tumor-suppressive and anti-angiogenic effect in an in vivo PC model. In the clinic, miR-1-mediated anti-angiogenesis would result in reduced tumor supply and increased hypoxic stress inside the tumor. Thus, miR-1 restoration by nucleic acid-based miR-1 mimetics would represent a promising option for future PC therapy.

Effects of Cold Atmospheric Plasma on the Expression of Chemokines, Growth Factors, TNF Superfamily Members, Interleukins, and Cytokines in Human Osteosarcoma Cells

BACKGROUND/AIM

Therapeutic options for osteosarcoma (OS) are still limited. Cold atmospheric plasma (CAP) leads to inhibition of tumor growth and metastasis, but underlying mechanisms are not fully understood. The aim of this study was to investigate CAP-induced changes in cytokine expression in OS cells.

MATERIALS AND METHODS

OS cell lines (U2-OS, MNNG/HOS) were treated with CAP and administered to an RT2 Profiler PCR Array (Qiagen, Hilden, Germany) detecting 84 chemokines, growth factors, TNF superfamily members, interleukins, and cytokines.

RESULTS

The analyses showed that 15 factors (C5, CCL5, CNTF, CSF1, CSF3, CXCL1, IL-1A, IL-1B, IL-18, IL-22, IL23A, MSTN, NODAL, TGFβ2, THPO) were induced, but only one factor (VEGFA) was suppressed after CAP treatment.

CONCLUSION

No extensive systemic cell response with presumably far-reaching consequences for neighboring cells was detectable after CAP treatment. Since the antitumoral effect of CAP on OS cells has already been demonstrated, intraoperative treatment with CAP represents a promising and systemic safe option for the therapy of OS.

Cabazitaxel inhibits prostate cancer cell growth by inhibition of androgen receptor and heat shock protein expression

PURPOSE

Cabazitaxel, a semi-synthetic taxane of the third generation, inhibits prostate cancer (PC) cell growth by affecting the microtubule architecture. Since cabazitaxel has also been demonstrated to inhibit androgen receptor (AR) functionality, AR and AR-associated heat shock protein (HSP) expressions in the presence of cabazitaxel were characterized.

METHODS

AR and HSP expressions were assessed via Western blotting utilizing a PC-cell-line in vitro system incubated with cabazitaxel.

RESULTS

Incubation experiments with 0.3 nM cabazitaxel exhibited significantly reduced levels of AR and the AR-associated factors HSP90α, HSP40, and HSP70/HSP90 organising protein. Furthermore, expression of the anti-apoptotic factor HSP60 was suppressed. In contrast to other anticancer compounds, cabazitaxel did not alter the cytoprotective chemoresistance factor HSP27.

CONCLUSIONS

Despite the deregulation of microtubule organisation, cabazitaxel has been shown to suppress the expression of HSP. Very notably, and may be as a result of down-regulated HSP, cabazitaxel additionally inhibits the expression of the AR in AR-positive PC cells. Thus, cabazitaxel bears an additional anti-proliferative activity which is at least in part specific for PC cells.

Lack of chemokine (C-C motif) ligand 3 leads to decreased survival and reduced immune response after bacterial meningitis

Pneumococcal meningitis, caused by Streptococcus pneumoniae, is the most common type of bacterial meningitis. The clinical management of this disease has been challenged by the emergence of multidrug-resistant Streptococcus pneumoniae, requiring the urgent development of new therapeutic alternatives. Over the course of bacterial meningitis, pathogen invasion is accompanied by a massive recruitment of peripheral immune cells, especially neutrophil granulocytes, which are recruited under the coordination of several cytokines and chemokines. Here, we used chemokine (C-C motif) ligand 3 (Ccl3)-deficient mice to investigate the functional role of CCL3 in a mouse model of pneumococcal meningitis. Following intrathecal infection with Streptococcus pneumoniae Ccl3-deficient mice presented a significantly shorter survival and higher bacterial load than wildtype mice, paralleled by an ameliorated infiltration of neutrophil granulocytes into the CNS. Blood sample analysis revealed that infected Ccl3-deficient mice showed a significant decrease in erythrocytes, hemoglobin and hematocrit as well as in the number of banded neutrophils. Moreover, infected Ccl3-deficient mice showed an altered cytokine expression profile. Glial cell activation remained unchanged in both genotypes. In summary, this study demonstrates that CCL3 is beneficial in Streptococcus pneumoniae-induced meningitis. Pharmacological modulation of the CCL3 pathways might, therefore, represent a future therapeutic option to manage Streptococcus pneumoniae meningitis.

MicroRNA-1 and MicroRNA-21 Individually Regulate Cellular Growth of Non-malignant and Malignant Renal Cells

BACKGROUND/AIM

Due to its poor prognosis, it is increasingly necessary to understand the biology of renal cell cancer (RCC). Therefore, we investigated the role of microRNAs miR-1 and miR-21 in the growth of RCC cells compared to that of non-malignant renal cells.

MATERIALS AND METHODS

Four malignant cell lines (Caki-1, 786-O, RCC4, A498) were examined regarding their cell growth, microRNA and telomerase expression, and were compared to non-malignant RC-124 renal cells.

RESULTS

Inconsistencies appeared in the panel of RCC cells regarding antiproliferative and proliferative properties of miR-1 and miR-21, respectively. Notably, and most likely due to immortaliziation, non-malignant RC-124 cells exhibited telomerase expression and activity.

CONCLUSION

miR-1 and miR-21 functionality in cancer progression, particularly in tumor growth, may be more dependent on the individual cellular context and may reflect RCC heterogeneity. Thus, both microRNAs, in combination with other stratifying biomarkers, may be useful in terms of RCC diagnosis, prognosis, or treatment response.

Functionality of the Tumor Suppressor microRNA-1 in Malignant Tissue and Cell Line Cells of Uterine Leiomyosarcoma

BACKGROUND/AIM

Uterine leiomyosarcoma (uLMS) is a very rare mesenchymal tumor showing an aggressive clinical course and poor prognosis for patients. Due to the low incidence, little is known about molecular tumor biology and biomarkers of uLMS. Micro-RNA-1 (miR-1) has been identified as a pivotal tumor suppressor in numerous entities being suited as a molecular marker for tumor progression.

MATERIALS AND METHODS

uLMS patient samples were analyzed regarding their miR-1 expression levels. Furthermore, miR-1 growth inhibitory and target regulatory properties were examined in transfected uLMS cells SK-UT-1.

RESULTS

miR-1 was strongly suppressed in uLMS tumor tissue compared to adjacent healthy tissue. In vitro studies, however, failed to detect growth inhibitory properties of miR-1 in SK-UT-1 cells. The expression of the cell survival and MAP kinases Erk-1/2 and p38 was not targeted by miR-1.

CONCLUSION

Tumor suppressive mechanisms of miR-1, seem to be inhibited in uLMS SK-UT-1 cells, maybe as part of the malignant transformation process. Regardless of the microRNA's cellular functionality, miR-1 may represent a promising biomarker of diagnosis in uLMS therapy.

Characterization and Management of Borderline Ovarian Tumors - Results of a Retrospective, Single-center Study of Patients Treated at the Department of Gynecology and Obstetrics of the University Medicine Greifswald

BACKGROUND/AIM

Borderline ovarian tumors (BOT) are malignant epithelial ovarian tumors with a very low incidence, therefore lacking sufficient clinical experience in diagnostics and treatment. This study characterized the histology, clinical features, diagnostics and therapy of BOT including patients treated at the Department of Gynecology and Obstetrics of the University Medicine Greifswald.

MATERIALS AND METHODS

In this retrospective, single-center study, patients with BOT treated between 1990 and 2010 were analyzed according to their histological and clinical reports.

RESULTS

A total of 54 patients were enrolled. The median age was 54.6 (range=23-83) years. Distribution of histological subtypes was: serous in 31 patients (57.4 %) and mucinous in 23 patients (42.6%). All patients underwent surgery. Eight patients (14.8%) were treated according to actual therapy recommendations during the initial surgery. Eight patients (14.8%) received adjuvant chemotherapy contrary to treatment recommendations. In the case of 36 patients (66.7%), a frozen section was taken intraoperatively, which matched the definitive histological result in 88.9%. During average follow-up of 70.3 months (range=0-231 months), two patients (3.7%) developed tumor recurrence after 9 and 29 months, respectively, two patients (3.7%) died of causes other than BOT.

CONCLUSION

Our study critically demonstrated that until a few years ago, BOTs were not usually treated according to international therapy recommendations. Nevertheless, the rate of tumor recurrence was very low.

Cold Atmospheric Plasma (CAP) and CAP-Stimulated Cell Culture Media Suppress Ovarian Cancer Cell Growth - A Putative Treatment Option in Ovarian Cancer Therapy

BACKGROUND/AIM

Ovarian cancer (OC) is a gynecologic tumor with poor prognosis. Despite radical cytoreductive surgery and platinum-based adjuvant systemic treatment, OC will relapse in the majority of the cases. Thus, cold atmospheric plasma (CAP), a highly reactive physical state bearing diverse biological activities being suited for anticancer therapy, may be a promising option in OC therapy.

MATERIALS AND METHODS

OC cell lines were exposed either directly to the CAP or to cell culture medium previously exposed to CAP. Cell proliferation and cell motility was measured.

RESULTS

The data demonstrated, that even a single application of a short-term CAP treatment led to an attenuation of OC cell growth and motility. Moreover, incubation with CAP-treated cell culture medium gave similar effects. Results were consistent in four OC cell lines.

CONCLUSION

In summary, the CAP application in oncological surgery leads to strong anti-proliferative effects and opens up novel opportunities for the OC treatment.

Y-box Binding Protein-1 Enhances Oncogenic Transforming Growth Factor β Signaling in Breast Cancer Cells via Triggering Phospho-Activation of Smad2

BACKGROUND/AIM

Transforming growth factor β (TGFβ) plays a role in diverse oncogenic pathways including cell proliferation and cell motility and is regulated by the pleiotropic factor Y-box binding protein-1 (YB-1). In breast cancer, Sma/Mad related protein 2 (Smad2) represents the most common downstream transducer in TGFβ signaling.

MATERIALS AND METHODS

Here, YB-1's impact on Smad2 phospho-activation was characterized by incubation of the breast cancer cell line MCF-7 with or without TGFβ1 in the absence or presence of overexpressed YB-1 protein. The phospho-status of Smad2 was assessed via western blotting.

RESULTS

Analysis of MCF-7 cells revealed no induction of total Smad2 neither in the presence of TGFβ1, nor during YB-1 overexpression. In contrast, incubation with TGFβ1 led to an increase of phosphorylated Smad2 forms which was significantly amplified by simultaneously overexpressed YB-1 (2.8±0.2-fold).

CONCLUSION

Oncogenic YB-1 indirectly enhances TGFβ signaling cascades via Smad2 phospho-activation and may represent a promising factor for future diagnosis and therapy of breast cancer.

Comparison of Cold Atmospheric Plasma Devices' Efficacy on Osteosarcoma and Fibroblastic In Vitro Cell Models

BACKGROUND/AIM

Cold atmospheric plasma (CAP) attenuates tumor cell proliferation and induces apoptosis in various cell lines. While exerting marginal effects on non-neoplastic cells this unfolds promising applications in cancer therapy. The aim of the study was to analyse the effects of different CAP sources and application times on osteosarcoma (OS) cells and non-malignant fibroblast cell proliferation.

MATERIALS AND METHODS

U2-OS and 3-T-3 fibroblasts were treated with three different approved medical devices. Carrier gas-treated cells served as controls. Cell proliferation was determined by viable cell count at different time points after treatment.

RESULTS

Control exposed U2-OS and 3-T-3 cells exhibited characteristic cell growth. CAP application of U2-OS and 3-T-3 cells attenuated proliferation rates up to 98%. Attenuation rates varied between cell lines, plasma sources and application times.

CONCLUSION

CAP treatment attenuates cell proliferation of OS cancer cells and fibroblasts in a treatment time-dependent manner, whereby U2-OS cells appeared more sensitive to CAP treatment as 3T3 fibroblasts after 10 sec of treatment.

Cold Atmospheric Plasma in the Treatment of Osteosarcoma

Human osteosarcoma (OS) is the most common primary malignant bone tumor occurring most commonly in adolescents and young adults. Major improvements in disease-free survival have been achieved by implementing a combination therapy consisting of radical surgical resection of the tumor and systemic multi-agent chemotherapy. However, long-term survival remains poor, so novel targeted therapies to improve outcomes for patients with osteosarcoma remains an area of active research. This includes immunotherapy, photodynamic therapy, or treatment with nanoparticles. Cold atmospheric plasma (CAP), a highly reactive (partially) ionized physical state, has been shown to inherit a significant anticancer capacity, leading to a new field in medicine called “plasma oncology.” The current article summarizes the potential of CAP in the treatment of human OS and reviews the underlying molecular mode of action.

Cold atmospheric plasma in orthopaedic and urologic tumor therapy

Cold atmospheric plasma (CAP) is a highly reactive ionized physical state thereby provoking divers biological effects. In medical applications, CAP treatment promotes wound healing, provokes immunostimulation, and is antiseptically active. Moreover, CAP interacts with antiproliferative mechanisms suggesting CAP treatment as a promising anticancer strategy. Here we review the current state of science concerning the so far investigated CAP effects on different cancer entities in orthopaedic and urologic oncology.

Formyl Peptide Receptor 1-Mediated Glial Cell Activation in a Mouse Model of Cuprizone-Induced Demyelination

Multiple sclerosis (MS) is a chronic degenerative disease of the central nervous system that is characterized by myelin abnormalities, oligodendrocyte pathology, and concomitant glia activation. Unclear are the factors triggering gliosis and demyelination. New findings suggest an important role of the innate immune response in the initiation and progression of active demyelinating lesions. The innate immune response is induced by pathogen-associated or danger-associated molecular patterns, which are identified by pattern recognition receptors (PRRs), including the G-protein coupled with formyl peptide receptors (FPRs). Glial cells, the immune cells of the central nervous system, also express the PRRs. In this study, we used the cuprizone mice model to investigate the expression of the FPR1 in the course of cuprizone-induced demyelination In addition, we used FPR1-deficient mice to analyze glial cell activation through immunohistochemistry and real-time RT-PCR in cuprizone model. Our results revealed a significantly increased expression of FPR1 in the cortex of cuprizone-treated mice. FPR1-deficient mice showed a slight but significant decrease of demyelination in the corpus callosum compared to the wild-type mice. Furthermore, FPR1 deficiency resulted in reduced glial cell activation and mRNA expression of microglia/macrophages markers, as well as pro- and anti-inflammatory cytokines in the cortex, compared to wild-type mice after cuprizone-induced demyelination. Combined together, these results suggest that the FPR1 is an important part of the innate immune response in the course of cuprizone-induced demyelination.

Peroxiredoxin Expression of Human Osteosarcoma Cells Is Influenced by Cold Atmospheric Plasma Treatment

BACKGROUND/AIM

To evaluate the potential involvement of redox-specific signalling pathways in cold atmospheric plasma (CAP)-induced apoptosis on human osteosarcoma cells.

MATERIALS AND METHODS

Osteosarcoma cell lines were treated with CAP with or without antioxidative agents and seeded in cell culture plates. Cell proliferation was determined by counting viable cells. Carrier gas-treated cells served as control. Peroxiredoxin (PRX) 1-3 expression and secretion were assessed.

RESULTS

CAP treatment exhibited strongly attenuated proliferation rates. This effect was significantly attenuated by the addition of N-acetylcysteine (NAC). CAP-treated cells exhibited an increase of PRX 1 and 2 10 sec after treatment. The ratio of oxidized to reduced PRX1 and PRX2 was significantly altered with increasing cellular concentration of the oxidized dimer.

CONCLUSION

Antioxidant supplementation with NAC increases proliferation of CAP-treated osteosarcoma cells, implicating an involvement of redox signalling. Activation of PRX1 and -2 indicate CAP affects redox homeostasis.