Effects of gamma-radiation on cell growth, cycle arrest, death, and superoxide dismutase expression by DU 145 human prostate cancer cells

Lyophilized Progenitor Tenocyte Extracts: Sterilizable Cytotherapeutic Derivatives with Antioxidant Properties and Hyaluronan Hydrogel Functionalization Effects

Cultured primary progenitor tenocytes in lyophilized form were previously shown to possess intrinsic antioxidant properties and hyaluronan-based hydrogel viscosity-modulating effects in vitro. The aim of this study was to prepare and functionally characterize several stabilized (lyophilized) cell-free progenitor tenocyte extracts for inclusion in cytotherapy-inspired complex injectable preparations. Fractionation and sterilization methods were included in specific biotechnological manufacturing workflows of such extracts. Comparative and functional-oriented characterizations of the various extracts were performed using several orthogonal descriptive, colorimetric, rheological, mechanical, and proteomic readouts. Specifically, an optimal sugar-based (saccharose/dextran) excipient formula was retained to produce sterilizable cytotherapeutic derivatives with appropriate functions. It was shown that extracts containing soluble cell-derived fractions possessed conserved and significant antioxidant properties (TEAC) compared to the freshly harvested cellular starting materials. Progenitor tenocyte extracts submitted to sub-micron filtration (0.22 µm) and 60Co gamma irradiation terminal sterilization (5−50 kGy) were shown to retain significant antioxidant properties and hyaluronan-based hydrogel viscosity modulating effects. Hydrogel combination products displayed important efficacy-related characteristics (friction modulation, tendon bioadhesivity) with significant (p < 0.05) protective effects of the cellular extracts in oxidative environments. Overall, the present study sets forth robust control methodologies (antioxidant assays, H2O2-challenged rheological setups) for stabilized cell-free progenitor tenocyte extracts. Importantly, it was shown that highly sensitive phases of cytotherapeutic derivative manufacturing process development (purification, terminal sterilization) allowed for the conservation of critical biological extract attributes.

Radiotherapy of the Hepatocellular Carcinoma in Mice Has a Time-Of-Day-Dependent Impact on the Mouse Hippocampus

Chronic liver diseases including hepatocellular carcinoma (HCC) create a state of chronic inflammation that affects the brain via the liver-brain axis leading to an alteration of neurotransmission and cognition. However, little is known about the effects of HCC on the hippocampus, the key brain region for learning and memory. Moreover, radiotherapy used to treat HCC has severe side effects that impair patients' life quality. Thus, designing optimal strategies, such as chronotherapy, to enhance the efficacy and reduce the side effects of HCC treatment is critically important. We addressed the effects of HCC and the timed administration of radiotherapy in mice on the expression of pro-inflammatory cytokines, clock genes, markers for glial activation, oxidative stress, neuronal activity and proliferation in the hippocampal neurogenic niche. Our data showed that HCC induced the upregulation of genes encoding for pro-inflammatory cytokines, altered clock gene expressions and reduced proliferation in the hippocampus. Radiotherapy, in particular when applied during the light/inactive phase enhanced all these effects in addition to glial activation, increased oxidative stress, decreased neuronal activity and increased levels of phospho(p)-ERK. Our results suggested an interaction of the circadian molecular clockwork and the brain's innate immune system as key players in liver-brain crosstalk in HCC and that radiotherapy when applied during the light/inactive phase induced the most profound alterations in the hippocampus.

Exosome secretion and cellular response of DU145 and PC3 after exposure to alpha radiation

Exosomes are spherical membrane nanovesicles secreted from cells, and they play an important role in tumor immune response, metastasis, angiogenesis, and survival. Studies investigating exosomes isolated from cells exposed to photon radiation commonly used in conventional radiotherapy demonstrate the influence of this type of radiation on exosome characteristics and secretion. There is currently no research investigating the effects of densely ionizing particles such as protons and alpha radiation on exosomes. Thus we have evaluated the cellular response of human prostate cancer cells exposed to 0, 2, and 6 Gy of alpha radiation emitted from the Am-241 source. Irradiated PC3 and DU145 cell lines, characterized by differences in radiosensitivity, were studied using apoptosis, LDH, and IL-6 assays. Additionally, the corresponding concentration and size of isolated exosomes were measured using NTA. We found that exposure to ionizing radiation resulted in gross changes in viability and cell damage. There were increased amounts of apoptotic or necrotic cells as a function of radiation dose. We demonstrated that irradiated PC3 cells secrete higher quantities of exosomes compared to DU145 cells. Additionally, we also found no statistical difference in exosome size for control and irradiated cells.

Chemotherapy and Physical Therapeutics Modulate Antigens on Cancer Cells

Cancer cells possess specific properties, such as multidrug resistance or unlimited proliferation potential, due to the presence of specific proteins on their cell membranes. The release of proliferation-related proteins from the membrane can evoke a loss of adaptive ability in cancer cells and thus enhance the effects of anticancer therapy. The upregulation of cancer-specific membrane antigens results in a better outcome of immunotherapy. Moreover, cytotoxic T-cells may also become more effective when stimulated ex-vivo toward the anticancer response. Therefore, the modulation of membrane proteins may serve as an interesting attempt in anticancer therapy. The presence of membrane antigens relies on various physical factors such as temperature, exposure to radiation, or drugs. Therefore, changing the tumor microenvironment conditions may lead to cancer cells becoming sensitized to subsequent therapy. This paper focuses on the therapeutic approaches modulating membrane antigens and enzymes in anticancer therapy. It aims to analyze the possible methods for modulating the antigens, such as pharmacological treatment, electric field treatment, photodynamic reaction, treatment with magnetic field or X-ray radiation. Besides, an overview of the effects of chemotherapy and immunotherapy on the immunophenotype of cancer cells is presented. Finally, the authors review the clinical trials that involved the modulation of cell immunophenotype in anticancer therapy.

Nanoparticles for active combination radio mitigating agents of zinc coumarate and zinc caffeinate in a rat model

Zinc coumarate and zinc caffeinate nanoparticles (ZnCoNPs, ZnCaNPs) affect different biological processes. This study aimed to evaluate the mitigating action of ZnCoNPs in combination with ZnCaNPs against liver damage induced by gamma rays (γ-rays). Rats were exposed to 7 Gy of γ-rays and then injected intraperitoneally (i.p) with ZnCoNPs [2U/rat/day (5 mg/kg)] and ZnCaNPs [2U/rat/day (15 mg/kg)] for 7 consecutive days. The results showed that irradiated rats treated with ZnCoNPs (5 mg/kg/body weight) in combination with ZnCaNPs (15 mg/kg/body weight) for 7 days had a significant increases in body weight, antioxidant levels, T helper cell 4 (cluster of differentiation 4 (CD4)), and T cytotoxic cell 8 (cluster of differentiation 8 (CD8)), associated with a marked decrease in lipid peroxidation (LP), nitric oxide(NOx), total free radicals concentrate (TFRC), and DNA fragmentation. There were positive alterations in the morphological state, hematological parameters and the cell cycle phases. Additionally, the histopathological study demonstrated an improvement in the liver tissue of irradiated rats after treatment. Thus, ZnCoNPs and ZnCaNPs could be used as natural mitigating agents to reduce the hazards of ionizing radiation.

PA1 cells containing a truncated DNA polymerase β protein are more sensitive to gamma radiation

Purpose: DNA polymerase β (Polβ) acts in the base excision repair (BER) pathway. Mutations in DNA polymerase β (Polβ) are associated with different cancers. A variant of Polβ with a 97 amino acid deletion (PolβΔ), in heterozygous conditions with wild-type Polβ, was identified in sporadic ovarian tumor samples. This study aims to evaluate the gamma radiation sensitivity of PolβΔ for possible target therapy in ovarian cancer treatment.Materials and Methods: PolβΔ cDNA was cloned in a GFP vector and transfected in PA1 cells. Stable cells (PA1PolβΔ) were treated with 60Co sourced gamma-ray (0–15 Gy) to investigate their radiation sensitivity. The affinity of PolβΔ with DNA evaluated by DNA protein in silico docking experiments.Result: The result showed a statistically significant (p < 0.05) higher sensitivity towards radiation at different doses (0–15 Gy) and time-point (48–72 hours) for PA1PolβΔ cells in comparison with normal PA1 cells. Ten Gy of gamma radiation was found to be the optimal dose. Significantly more PA1PolβΔ cells were killed at this dose than PA1 cells after 48 hours of treatment via an apoptotic pathway. The in silico docking experiments revealed that PolβΔ has more substantial binding potential towards the dsDNA than wild-type Polβ, suggesting a possible failure of BER pathway that results in cell death.Conclusion: Our study showed that the PA1PolβΔ cells were more susceptible than PA1 cells to gamma radiation. In the future, the potentiality of ionizing radiation to treat this type of cancer will be checked in animal models.

Oxidative stress in obesity and insulin resistance

Since obesity is one of the main factors in the development of insulin resistance (IR) and is also associated with increased oxidative stress (OxS) rate, this study aims to review the published literature to collate and provide a comprehensive summary of the studies related to the status of the OxS in the pathogenesis of obesity and related IR. OxS represents an imbalance between the production of reactive oxygen and nitrogen species (RONS) and the capacity of the antioxidant defense system (AOS) to neutralize RONS. A steady-state of RONS level is maintained through endogenous enzymatic and non-enzymatic AOS components. Three crucial enzymes, which suppress the formation of free radicals, are superoxide dismutases, catalases, and glutathione peroxidases. The second line of AOS includes non-enzymatic components such as vitamins C and E, coenzyme Q, and glutathione which neutralizes free radicals by donating electrons to RONS. Emerging evidence suggests that high RONS levels contribute to the progression of OxS in obesity by activating inflammatory pathways and thus leading to the development of pathological states, including IR. In addition, decreased level of AOS components in obesity increases the susceptibility to oxidative tissue damage and further progression of its comorbidities. Increased OxS in accumulated adipose tissue should be an imperative target for developing new therapies in obesity-related IR.

Antioxidant enzymes and vascular diseases

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a fundamental role in regulating endothelial function and vascular tone in the physiological conditions of a vascular system. However, oxidative stress has detrimental effects on human health, and numerous studies confirmed that high ROS/RNS production contributes to the initiation and progression of cardiovascular diseases. The antioxidant defense has an essential role in the homeostatic functioning of the vascular endothelial system. Endogenous antioxidative defense includes various molecules and enzymes such as superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase. Together all these antioxidative enzymes are essential for defense against harmful ROS features. ROS are mainly generated from redox-active compounds involved in the mitochondrial respiratory chain. Thus, targeting antioxidative enzymes and mitochondria oxidative balance may be a promising approach for vascular diseases occurrence and treatment. This review summarized the most recent research on the regulation of antioxidative enzymes in vascular diseases.

Relationship between locomotor activity rhythm and corticosterone levels during HCC development, progression, and treatment in a mouse model

Cancer-related fatigue (CRF) and stress are common symptoms in cancer patients and represent early side effects of cancer treatment which affect the life quality of the patients. CRF may partly depend on disruption of the circadian rhythm. Locomotor activity and corticosterone rhythms are two important circadian outputs which can be used to analyze possible effects on the circadian function during cancer development and treatment. The present study analyzes the relationship between locomotor activity rhythm, corticosterone levels, hepatocellular carcinoma (HCC) development, and radiotherapy treatment in a mouse model. HCC was induced in mice by single injection of diethylnitrosamine (DEN) and chronic treatment of phenobarbital in drinking water. Another group received chronic phenobarbital treatment only. Tumor bearing animals were divided randomly into four groups irradiated at four different Zeitgeber time points. Spontaneous locomotor activity was recorded continuously; serum corticosterone levels and p-ERK immunoreaction in the suprachiasmatic nucleus (SCN) were investigated. Phenobarbital treated mice showed damped corticosterone levels and a less stable 24 hours activity rhythm as well as an increase in activity during the light phase, reminiscent of sleep disruption. The tumor mice showed an increase in corticosterone level during the inactive phase and decreased activity during the dark phase, reminiscent of CRF. After irradiation, corticosterone levels were further increased and locomotor activity rhythms were disrupted. Lowest corticosterone levels were observed after irradiation during the early light phase; thus, this time might be the best to apply radiotherapy in order to minimize side effects.

Implications of ionizing radiation on pollen performance in comparison with diverse models of polar cell growth

Research concerning the effects of ionizing radiation (IR) on plant systems is essential for numerous aspects of human society, as for instance, in terms of agriculture and plant breeding, but additionally for elucidating consequences of radioactive contamination of the ecosphere. This comprehensive survey analyses effects of x- and γ-irradiation on male gametophytes comprising primarily in vitro but also in vivo data of diverse plant species. The IR-dose range for pollen performance was compiled and 50% inhibition doses (ID₅₀ ) for germination and tube growth were comparatively related to physiological characteristics of the microgametophyte. Factors influencing IR-susceptibility of mature pollen and polarized tube growth were evaluated, such as dose-rate, environmental conditions, or species-related variations. In addition, all available reports suggesting bio-positive IR-effects particularly on pollen performance were examined. Most importantly, for the first time influences of IR specifically on diverse phylogenetic models of polar cell growth were comparatively analysed, and thus demonstrated that the gametophytic system of pollen is extremely resistant to IR, more than plant sporophytes and especially much more than comparable animal cells. Beyond that, this study develops hypotheses regarding a molecular basis for the extreme IR-resistance of the plant microgametophyte and highlights its unique rank among organismal systems.

Radioprotective potential of Lagenaria siceraria extract against radiation-induced gastrointestinal injury

The cucurbits (prebiotics) were investigated as novel agents for radio-modification against gastrointestinal injury. The cell-cycle fractions and DNA damage were monitored in HCT-15 cells. A cucurbit extract was added to culture medium 2 h before irradiation (6 Gy) and was substituted by fresh medium at 4 h post-irradiation. The whole extract of the fruits of Lagenaria siceraria, Luffa cylindrica, or Cucurbita pepo extract enhanced G2 fractions (42%, 34%, and 37%, respectively) as compared with control (20%) and irradiated control (31%). With cucurbits, the comet tail length remained shorter (L. siceraria, 28 μm; L. cylindrica, 34.2 μm; C. pepo, 36.75 μm) than irradiated control (41.75 μm). For in vivo studies, L. siceraria extract (2 mg/kg body weight) was administered orally to mice at 2 h before and 4 and 24 h after whole-body irradiation (10 Gy). L. siceraria treatment restored the glutathione contents to 48.8 μmol/gm as compared with control (27.6 μmol/gm) and irradiated control (19.6 μmol/gm). Irradiation reduced the villi height from 379 to 350 μm and width from 54 to 27 μm. L. siceraria administration countered the radiation effects (length, 366 μm; width, 30 μm, respectively) and improved the villi morphology and tight junction integrity. This study reveals the therapeutic potential of cucurbits against radiation-induced gastrointestinal injury.

L-carnitine protects against testicular dysfunction caused by gamma irradiation in mice

This study was conducted on mice to evaluate the radioprotective role of L-carnitine against γ-ray irradiation-induced testicular damage. Adult male mice were exposed to whole body irradiation at a total dose of 1 Gy. Radiation exposure was continued 24 h a day (0.1 Gy/day) throughout the 10 days exposure period either in the absence and/or presence of L-carnitine at an i.p. dose of 10 mg/kg body weight/day. Results revealed that γ-rays irradiation suppressed the expression of ABP and CYP450SCC mRNA, whereas treatment with L-carnitine prior and throughout γ-rays irradiation exposure inhibited this suppression. Treatment with γ-ray irradiation or L-carnitine down-regulated expression of aromatase mRNA. With combined treatment, L-carnitine significantly normalized aromatase expression. γ-Ray irradiation up-regulated expression of FasL and Cyclin D2 mRNA, while L-carnitine inhibited these up-regulations. Results also showed that γ-ray-irradiation up-regulated TNF-α, IL1-β and IFN-γ mRNA expressions compared to either controls or the L-carnitine treated group. Moreover, γ-irradiation greatly reduced serum testosterone levels, while L-carnitine, either alone or in combination with irradiation, significantly increased serum testosterone levels compared to controls. In addition, γ-irradiation induced high levels of sperm abnormalities (43%) which were decreased to 12% in the presence of L-carnitine. In parallel with these findings, histological examination showed that γ-irradiation induced severe tubular degenerative changes, which were reduced by L-carnitine pre-treatment. These results clarified the immunostimulatory effects of L-carnitine and its radioprotective role against testicular injury.

Green tea extract (epigallocatechin-3-gallate) reduces efficacy of radiotherapy on prostate cancer cells

OBJECTIVES

To assess the influence of epigallocatechin-3-gallate (EGCG) on the efficacy of ionizing radiation on prostate cancer cells because of the increased use of dietary interventions, especially by patients with prostate cancer. Radiotherapy is used to treat localized prostate cancer. Some people consume green tea (EGCG) as a chemopreventive agent against prostate cancer. Green tea can act as an antioxidant and induce superoxide dismutase enzymes, which could scavenge the free oxygen radicals generated by radiotherapy.

METHODS

Prostate cancer cell line DU145 cells were treated with EGCG or radiotherapy, or both. Cell death was assessed using trypan blue cell counting, and apoptosis was confirmed by assessing poly (adenosine phosphate ribose) polymerase cleavage. The antioxidant potential was assessed using Western immunoblotting for manganese superoxide dismutase and copper zinc superoxide dismutase enzymes. Radiotherapy was delivered using a linear accelerator. Cell cycle analysis was performed using flow cytometry.

RESULTS

Radiotherapy at 3.5 Gy induced a 5.9-fold increase in apoptosis of DU145 cells. Subapoptotic doses of EGCG (1.5-7.5 μM) significantly reduced ionizing radiation-induced apoptosis (P < .001), with the inhibitory effect of EGCG on ionizing radiation being most effective when added 30 minutes before radiotherapy (P < .001). In addition, when radiotherapy and EGCG were used together, an approximate 1.5-fold increase in manganese superoxide dismutase levels was seen compared with the control and a 2-fold increase compared with radiotherapy alone.

CONCLUSIONS

Radiotherapy is effective in inducing apoptosis in DU145 cells, but its effect was significantly reduced in the presence of EGCG, and this was associated with an increase in the induction of manganese superoxide dismutase.

Experimental and systems biology studies of the molecular basis for the radioresistance of prostate carcinoma cells

Molecular mechanisms for the gamma-ionizing radiation (IR) resistance of human prostate cancer cells, PC-3, are not quite clear. Since the low-LET-IR effects are primarily manifested by the generation of reactive oxygen species (ROS), the IR-induced expressions both of ROS-metabolizing antioxidant enzymes, such as Mn- and CuZn superoxide dismutases (SODs) and catalase (Cat), and of the transcriptional nuclear factor-kappaB (NF-kappaB) were explored. A substantial increase in the concentrations of SODs was observed in the cells irradiated by 10 and 20 Gy relative to those irradiated by 0 and 2 Gy, while the Cat and NF-kappaB expressions were found to be fairly stable. A system biology model was developed to shed more light on how MnSOD affects the biological state of cells depending upon the production of H(2)O(2). By raising the initial presence of MnSOD in the 0.7-10 microM concentration range, the time-dependent concentrations of H(2)O(2) for various initial levels of MnSOD were contrasted. The radioresistance of PC-3 cells is suggested to be associated with the positive, feed-forward vicious circle established between the H(2)O(2)-mediated elevation of MnSOD expression.

The combination of gamma ionizing radiation and 8-Cl-cAMP induces synergistic cell growth inhibition and induction of apoptosis in human prostate cancer cells

The antiproliferative and cytotoxic potential of the nucleotide analog 8-Cl-cAMP was tested in PC-3 and DU145 metastatic human prostate cancer cells. The drug was examined as the only therapeutic agent and in combination with ionizing irradiation (IR). Highly synergistic effects of IR and 8-Cl-cAMP were observed in both cell lines when examined by the MTT viability and BrdU proliferation assays. The combination of IR and 8-Cl-cAMP at clinically relevant doses exerted substantial growth inhibition. The combination of IR and 8-Cl-cAMP caused a significant disturbance in the distribution of cell cycle phases. Cell cycle arrest in the sub-G0/G1 phase predominated in both cell lines. The most striking observation was a significant increase in apoptotic PC-3 and DU145 cells. The DU145 cells were three times more sensitive to the combined treatment than PC-3 cells. The initial resistance to IR-induced apoptosis in these p53-deficient prostate cancer cell lines was overcome through an alternative proapoptotic pathway induced by 8-Cl-cAMP. Considering the low effective doses of treatments, improved tumor eradication rates and minimal undesirable side effects, the combination of IR and 8-Cl-cAMP could be the therapy of choice in treating prostate cancer.

Deficient G2-M and S checkpoints are associated with increased lung cancer risk: a case-control analysis

Loss or attenuation of cell cycle checkpoint function can compromise the fidelity of DNA due to insufficient time to repair DNA damage. We evaluated cell cycle checkpoints in 747 patients with lung cancer and 745 controls by measuring the proportions of cultured peripheral blood lymphocytes in G2-M and S phases. As an indicator of G2-M phase or S phase cell cycle checkpoint function, the gamma-radiation-induced cell accumulation index at G2-M or S phase was defined as (percentage of cells in G2-M or S with ionizing radiation exposure - percentage of cells in G2-M or S without ionizing radiation exposure) / (percentage of cells in G2-M or S without ionizing radiation exposure). We found that the median cell accumulation index was significantly lower in patients than that in controls at both the G2-M phase (0.774 versus 0.882, P = 0.002) and the S phase (0.226 versus 0.243, P = 0.001). When the median value for the cell accumulation index at the G2-M or S phase in the controls was used as the cutoff point, the reduced indices at G2-M and S phases were associated with 1.28-fold (95% confidence interval, 1.04-1.58) and 1.30-fold (95% confidence interval, 1.06-1.61) increased lung cancer risks, respectively. Analyses stratified by histology showed some heterogeneity. Additionally, cell accumulation indices at both G2-M and S phases were not associated with clinical stages. We conclude that attenuated functions of G2-M and S cell cycle checkpoints might be susceptibility markers for lung cancer.