Conventional radiotherapy with X- and γ-rays is one of the common and effective treatments of cancer. High energy hadrons, i.e., charged particles like protons and 12C ions, due to their specific physics and radiobiological advantages are increasingly used. In this study, effectiveness of different radiation types is evaluated on the radio-resistant human HTB140 melanoma cells. The cells were irradiated with γ-rays, the 62 MeV protons at the Bragg peak and in the middle of the spread-out Bragg peak (SOBP), as well as with the 62 MeV/u 12 C ions. The doses ranged from 2 to 24 Gy. Cell survival and proliferation were assessed 7 days after irradiation, whereas apoptosis was evaluated after 48 h. The acquired results confirmed the high radio-resistance of cells, showing better effectiveness of protons than γ-rays. The best efficiency was obtained with 12C ions due to higher linear energy transfer. All analyzed radiation qualities reduced cell proliferation. The highest proliferation was detected for 12C ions because of their large killing capacity followed by small induction of reparable lesions. This enabled unharmed cells to preserve proliferative activity. Irradiations with protons and 12C ions revealed similar moderate pro-apoptotic ability that is in agreement with the level of cellular radio-resistance., A. Ristić-Fira ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Adjuvant therapy and radiotherapy improves the survival of patients with metastatic and locally advanced gastric cancer (GC). However, the resistance to radiotherapy limits its clinical usage. Rhotekin 2 (RTKN2) functions as an oncogene and confers resistance to ultraviolet B-radiation and apoptosis- inducing agents. Here, the role of RTKN2 in radiosensitivity of GC cell lines was investigated. RTKN2 was found to be elevated in GC tissues and cells. A series of functional assays revealed that overexpression of RTKN2 induced GC cell proliferation, promoted GC cell migration and invasion, while inhibiting GC cell apoptosis. However, silence of RTKN2 promoted GC cell apoptosis, while repressing GC cell proliferation, invasion and migration. GC cells were exposed to irradiation, and data from cell survival and apoptotic assays showed that knock-down of RTKN2 enhanced radiosensitivity of GC through up-regulation of apoptosis and down-regulation of proliferation in irradiation-exposed GC cells. Moreover, the protein expression of β-catenin and c-Myc in GC cells was enhanced by RTKN2 over-expression, but reduced by RTKN2 silence. Interference of RTKN2 down-regulated nuclear β-catenin expression, while up-regulating cytoplasmic β-catenin in GC. In conclusion, RTKN2 contributed to cell growth and radioresistance in GC through activation of Wnt/β-catenin signalling.
We have studied natural killer (NK) activity, lymphoproliferative response, the release of several cytokines (IL-2, TNFa and IL-1b) and the ROS production in peritoneal leukocytes obtained 0, 2, 4, 12 and 24 h after lipopolysaccharide (LPS) injection. Lethal septic shock (100 % mortality occurred at 30 h after LPS administration) was caused in female BALB/c mice by intraperitoneal injection of 100 mg/kg of E. coli LPS. Cytotoxicity and lymphoproliferation assay were preformed together with the measurement of IL-1b, IL-2 and TNFa production, and quantification of ROS. Natural killer activity, spontaneous lymphoproliferative response, IL-2, TNFa, IL-b release and ROS production were increased after LPS injection. In conclusions, ROS and proinflammatory mediators produced by immune cells in response to LPS are involved in the oxidative stress of endotoxic shock. This oxidative state alters some functional characteristics of leukocytes (proliferation and NK activity)., V. M. Víctor, M. De la Fuente., and Obsahuje bibliografii
The present paper deals with the regeneration of splenic tissue after autologous transplantation. Control and transplanted rats (60 days after operation (106 cells per injection). The effect of a primary response was studied by a single injection, long-lasting bacteraemia was imitated by 5 injections in weekly intervals. Spleens and transplants were investigated by flow-cytometry and immunohistochemistry. Additionally, the proliferation activity and the specific antibody production against Escherichia coli proteins were tested. Flow-cytometric analysis showed altered behaviour of T-helper cells and B-cells in transplants following a primary response, whereas in the multiple injection group a difference between the splenic and transplant response was restricted to macrophages and MHC II+ cells. The results of the morphometric analysis revealed that the cellular composition of unstimulated transplants was very similar to that of the spleen with some subtle alterations. Only the marginal zone showed more striking differences concerning the homing of several cell classes. Under stimulatory conditions, these subtle alterations became more drastic so that CD5 + cells, B-cells and macrophages responded in an abnormal manner in both groups. The analysis of thymidine kinase disclosed decreased activity in the spleen after weekly antigen stimulation. The stimulation index of all transplant groups was significantly lower than that of the spleen. The specific antibody (IgG) production after a single immunization was highest in the transplant group. All groups responded after the multiple challenge. In conclusion, the results demonstrate that splenic transplants differs in several, but subtle aspects from normal splenic tissue. The main reason for most of these alterations may be a slightly misguided recirculation and/or homing of cells.
The proportion of proliferating erythroblasts, i.e. proerythroblasts, basophilic erythroblasts and polychromatophilic erythroblasts in blood islands of the chick embryo yolk sac, were counted during embryonic days 2-10. From day 2 when high amounts of erythroblasts signalized the onset of embryonic erythropoiesis, the percentage of less mature erythroid cells gradually decreased. Intraamniotic injection of cyclosporin A in doses 1.5 or 15.0 /rg per embryo on day 5 led to significant changes in the proportion of proliferating erythroblasts in the yolk sac blood islands. We speculate that these changes were caused initially by the release of the more mature cells into the circulation and later by a dose-dependent decrease in the number of stem cells. The estimation of proerythroblast percentage from all proliferating erythroblasts in the yolk sac blood islands may serve as a valuable indication of toxic damage in the late avian embryo.
This comparative study of various surface treatments of commercially available implant materials is intended as guidance for orientation among particular surface treatment methods in term of the cell reaction of normal human osteoblasts and blood coagulation. The influence of physicochemical surface parameters such as roughness, surface free energy and wettability on the response of human osteoblasts in the immediate vicinity of implants and on the blood co agulation was studied. The osteoblast proliferation was monitored and the expression of tissue mediators (TNF-α , IL-8, MMP-1, bone alkaline phosphatase, VCAM-1, TGF-β ) was evaluated after the cell cultivation onto a wide range of commercially available materials (titanium and Ti6Al4V alloy with various surface treatments, CrCoMo alloy, zirconium oxide ceramics, polyethylene and carbon/carbon composite). The formation of a blood clot was investigated on the samples immersed in a freshly drawn whole rabbit blood using scanning electron microscope. The surfaces with an increased osteoblast proliferation exhibited particularly higher surface roughness (here Ra > 3.5 μm) followed by a high polar part of the surface free energy whereas the effect of wettability played a minor role. The surface roughness was also the main factor regulating the blood coagulation. The blood clot formation analys is showed a rapid coag ulum formation on the rough titanium-based surfaces. The titanium with an etching treatment was considered as th e most suitable candidate for healing into the bone tissue due to high osteoblast proliferation, the highest production of osteogenesis markers and low production of inflammatory cytokines and due to the most intensive blood clot formation., D. Kubies ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy