Methylnitrosourea, dimethylbenzanthracene and benzoapyrene differentially affect redox pathways, apoptosis and immunity in zebrafish.

Cancer continues to be a major cause of mortality globally. Zebrafish present suitable models for studying the mechanisms of genotoxic carcinogens. The aim of this study was to investigate the interaction between oxidant-antioxidant status, apoptosis and immunity in zebrafish that were exposed to three different genotoxic carcinogens methylnitrosourea, dimethylbenzanthracene, benzoapyrene and methylnitrosourea + dimethylbenzanthracene starting from early embryogenesis for 30 days. Lipid peroxidation, nitric oxide levels, superoxide dismutase and glutathione-S-transferase activities and mRNA levels of apoptosis genes p53, bax, casp3a, casp2 and immunity genes fas, tnfα and ifnγ1 were evaluated. The disruption of the oxidant-antioxidant balance accompanied by altered expressions of apoptotic and immunity related genes were observed in different levels according to the carcinogen applied. Noteworthy, ifnγ expressions decreased in all carcinogen-exposed groups. Our results will provide basic data for further carcinogenesis research in zebrafish models.

Rabies virus vaccine as an immune adjuvant against cancers and glioblastoma: new studies may resurrect a neglected potential.

To review the literature about the use of Rabies Virus-Vaccine (RV-V) as an anticancer immunotherapeutic modality in the light of recent findings. The literature search in relevant databases with the following key words: Rabies virus, cancer, remission. Remissions occured following RV-V injections in patients with cervical cancer and melanoma. Pilot clinical studies showed that RV-V injections enhanced survival in glioblastoma patients, which is supported by findings in GL261 mouse glioma model. If public health studies demonstrate protective role of RV-V against certain types of cancers, it can be benefitted as a novel immune adjuvant in clinic.

Trinucleotide repeat expansions in human breast cancer-susceptibility genes: relevant targets for aspirin chemoprevention?

PURPOSE: Defining novel molecular mechanisms pertinent to aspirin chemoprevention of breast cancer (BC) and to explain controversial epidemiological results in this regard. METHODS: Literature search in relevant databases with the following key words; aspirin, nucleotide repeat expansions, breast cancer. Human genome contains nucleotide repeat expansions and exon-1 of the androgen receptor gene AR contains a CAG string with an average of 20 repeats. Longer AR CAG repeats associate with lower AR protein functioning leading relatively higher estrogen receptor signals and higher risk of hormone receptor-positive BC. Nucleotide repeat expansions also exist in E2F4 and POLG genes in BC. In cell culture models, aspirin reduces CAG.CTG expansions in kidney cells and restores myogenic differentiation in cells obtained from tissues with myotonic dystrophy, a disorder caused by large CTG expansions. CONCLUSIONS: We hypothesize that aspirin reduction of trinucleotide repeat expansions in breast cancer-susceptibility genes may be one of the relevant mechanisms of its chemopreventive effects.

Human brains found in a fire-affected 4000-years old Bronze Age tumulus layer rich in soil alkalines and boron in Kutahya, Western Anatolia.

Undecomposed human bodies and organs always attracted interest in terms of understanding biological tissue stability and immortality. Amongst these, cases of natural mummification found in glaciers, bog sediments and deserts caused even more attention. In 2010, an archeological excavation of a Bronze Age layer in a tumulus near the Western Anatolia city Kütahya revealed fire affected regions with burnt human skeletons and charred wooden objects. Inside of the cracked skulls, undecomposed brains were discernible. To analyze the burial taphonomy of the rare phenomenon of brain preservation, we analyzed brains, bone, teeth and surrounding soils elements using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Adipocere formation or saponification of postmortem tissue fat requires high levels of alkalinity and especially potassium. Indeed, ICP-MS analysis of the brain, teeth and bone and also of the surrounding soil revealed high levels of potassium, magnesium, aluminum and boron, which are compatible with the famous role of Kütahya in tile production with its soil containing high level of alkalines and tile-glazing boron. Fatty acid chromatography revealed simultaneous saturation of fats and protection of fragile unsaturated fatty acids consistent with soil-presence of both pro-oxidant and anti-oxidant trace metals. Computerized tomography revealed protection of diencephalic, metencephalic and occipital tissue in one of the best-preserved specimens. Boron was previously found as an intentional preservative of Tutankhamen and Deir el Bahari mummies. Here, in natural soil with its insect-repellant, anti-bacterial and fire-resistance qualities it may be a factor to preserve heat-affected brains as almost bioporcellain specimens.

Differentiation-inducing liposoluble vitamin deficiency may explain frequent secondary solid tumors after hematopoietic stem cell transplantation: minireview.

Secondary cancers are among the most threatening long-term health problems of hematopoetic stem cell- transplant (HSCT) patients. There are several lines of evidence indicating the possibility of a prolonged Vitamin A deficiency for solid tumor-type secondary cancers: I- Solid tumors such as oral cavity, head/neck region squamous carcinomas, skin cancers and melanomas, where lowered Vitamin A concentrations and chemo-preventing activity of its derivatives (retinoids) are most explicitly proven, arise much more frequently than others. II- Early monitorings: A significant retinol deficiency in HSCT patients is detectable along with a severity of mucositis and the vulnerability to infection. III- Monitoring of other liposoluble vitamins: Vitamin D, a differentiation-inducing vitamin like Vitamin A, showed a sustained decrease. Another similarity of these two vitamins is that they also depend on intestinal absorption and are decreased due to bowel injury by conditioning agents and chronic graft-versus-host disease. IV- Peroxidative reactions and inflammation can directly exhaust retinol levels despite sufficient intake. Considering the similar inhibitory role of Vitamin D analogs (deltanoids) on squamous carcinomas, skin tumors and melanomas, we propose that animal studies and extended vitamin surveillance studies in HSCT patients may unfold a preventive strategy against long-term complications.

NF-kappaB, macrophage migration inhibitory factor and cyclooxygenase-inhibitions as likely mechanisms behind the acetaminophen- and NSAID-prevention of the ovarian cancer.

Recent epidemiological studies indicated risk reductions in ovarian cancer with consumption of acetaminophen or non-steroid anti-inflammatory drugs. Until now, there is not a systematic analysis, why these agents may reduce risk of ovarian cancer, as it has been performed to explain aspirin-reduction of colon cancer risk. This review tries to explain molecular mechanisms pertinent to acetaminophen- and NSAID-reduction of ovarian cancer. It is proposed that the major mechanism by these anti-inflammatory agents is a shared pathway dependent on the suppression of NF-kappaB activity, which may subsequently decrease transcription of growth factors, chemokines and proteases such as COX-2, VEGF, IL-8/CXCL8, MCP-1/CCL-2, MIP1alpha/CCL-3, tPA and uPA, which are shown to be elevated in ovarian carcinoma, and which play diverse roles such as inducing angiogenesis, invasion, autocrine growth loops and resistance to apoptosis. Besides these, specific mechanisms of action can be attributed to acetaminophen-reduction of ovarian cancer risk via I. Induction of specific reproductive atrophy due its sex-steroid resembling phenolic ring; II. Reduction of glutathione pools due to its NAPQI metabolite, which may play an important role for sterilizing pre-malignant ovarian lesions, since they are shown to lack proper levels of glutathione; III. Inhibition of tautomerization activity of MIF (macrophage migration inhibitory factor), which is shown to be released from ovarian cancer, and which is necessary for proper ovulation; IV. Inhibition of cytokine-induced and endothelia-origined cyclooxygenases. Except the chemosensitization studies, acetaminophen and NSAIDs should be investigated in animal models to test likely benefits in ovarian cancer, since most of their activity may origin from intervening with the cancer growth-stimulating inflammatory stimuli, rather than with the direct cellular toxicity.

Acetaminophen and DMSO modulate growth and gemcitabine cytotoxicity in FM3A breast cancer cells in vitro.

Addition of antioxidants to chemotherapy is an unresolved problem in oncology. It is still an issue of debate, whether antioxidants may reduce rough cellular toxicity and thereby the systemic side effects of the chemotherapy, without sacrificing the anti-tumor efficacy. Gemcitabine is a rather new anti-cancer agent, which is quite potent against a range of drug resistant tumors, particularly breast cancer. Tumor-sensitivity towards gemcitabine can be increased with COX inhibitory anti-inflammatory agents and ribonucleotide reductase (RR) inhibitor flavopiridol. Acetaminophen and DMSO are two unique anti-inflammatory and anti- oxidant agents with unrelated structures, yet both capable to block RR and COX, simultaneously. Using plating efficacy and 3H- thymidine labeling, we monitored efficacy of acetaminophen and DMSO to modulate growth and gemcitabine sensitivity in FM3A breast tumor cells, which is highly used to study thymineless death induced by nucleotide-metabolism hemming drugs. Peculiarly, acetaminophen alone stimulated S-phase, which was not accompanied with enhanced plating, rather resulting in 40.3% growth inhibition at the 96 hour. DMSO alone significantly diminished both the plating and S-phase, which resulted in 71.7% growth inhibition at the 96 hour. Gemcitabine drastically reduced S-phase and plating until 72 hours, yet at 96 hours it lost its efficacy to suppress the S-phase with concomitant 2-fold rise in cell numbers in comparison to 72 hour time point. Both DMSO and acetaminophen brought S-phase to around zero percent in combination with gemcitabine until 48 hours, yet they both reduced early cytotoxicity of gemcitabine at the same time interval. However, at the 96 hour, they both strongly augmented gemcitabine efficacy to block S-phase and prevented the rise in plating. Acetaminophen and DMSO should be tested in animal models, whether they could augment efficacy and reduce the toxicity of gemcitabine.

Acetaminophen modulations of chemotherapy efficacy in MDAH 2774 human endometrioid ovarian cancer cells in vitro.

Epidemiological data have correlated consumption of nonsteroidal antinflammatory drugs with lowered risk for many types of cancer, and some recent studies indicate a reverse correlation with acetaminophen consumption and ovarian malignancy. In this study we examined effects of acetaminophen on plating, S-phase and colony growth of MDAH 2774 human endometrioid ovarian carcinoma, as well as sensitivity of this cell line to carboplatin in all three tests, and paclitaxel to clonogenic assay. Acetaminophen significantly enhanced S-phase in first 72 hours and enhanced cell population in 96 hours of plating monitorization, but decreased one week colony growth by approximately 80%, which was in the range of cytotoxic drugs. Interestingly with low dose carboplatin in first 72 hours acetaminophen enhanced cell proliferation more profoundly, but only thereafter decreased cell growth synergistically with carboplatin. It did not effect paclitaxel colony growth inhibiting acitivity. MDAH-2774 cell line lack p-53 and MSH-2, which are both 'gatekeeper' apoptosis inducing genes against genome damaging insult. Thus, presence of lower doses of oxidizing drugs may help the induction of proliferative signals, but only their sustained presence may overcome such signals and ultimately bring to cell demise.

Vascularization pattern of C6 glioma is modified with medroxyprogesterone acetate and ibuprofen in Wistar rat brain.

Beneficial effects of medroxyprogesterone acetate (MPA) in cancer therapy is partly mediated via its antiangiogenic activity. The same is true for the antitumoral action of non-steroidal antiinflammatory drugs. We have studied two liposoluble drugs, MPA and the analgesic ibuprofen, on glioma vascularization in vivo. In this study we have shown that, until the sacrifice at 27. day after tumor inoculation in the right hemisphere, MPA had a slight though insignificant activity to reduce the fatality of C6 glioma, growing in right cerebral hemisphere of male Wistar rats. But ibuprofen both alone or with MPA had no effect on survival with gavage application of a 30 mg/kg/day dosing regime. On histological analysis, intra- and peritumoral vessels were counted. Progesterone seemed to lower intratumoral, but to increase peritumoral vessels, especially glomeruloids, around the tumor mass. Coadministration of ibuprofen acted to suppress the peritumoral vessel increase, and to enhance lymphomonocytic infiltration around tumor vessels.

Medroxyprogesterone acetate alone or synergistic with chemotherapy suppresses colony formation and DNA synthesis in C6 glioma in vitro.

We have studied the effects of medroxyprogesterone acetate (MPA) on C6 glioma growth in vitro in order to prove the hypothesis that it could arrest growth and induce drug sensitisation in a glial tumour as it does in breast cancer cells. Plating, thymidine-labelling index, ultra-structure, and soft agar colony growth were determined after incubation with MPA, and/or cisplatin, procarbazine and methotrexate (MTX). MPA (microg/ml) reduced the thymidine-labelling index by 41 and 73% at 48 and 96 h, respectively, and decreased colony growth by 61%. Soft agar colony inhibition by MPA was almost as potent as MTX (0.3 microg/ml), but the latter drug showed very high cytotoxicity. Electron microscopy revealed that in medroxyprogesterone treated cells myeloid bodies developed, but MTX treatment caused mainly necrosis. Medroxyprogesterone increased procarbazine and cisplatin-induced colony growth and S-phase inhibition, but reduced MTX-induced thymidine-labelling inhibition. In conclusion, progesterone may inhibit growth and sensitize to drugs.

Autophagy and nuclear changes in FM3A breast tumor cells after epirubicin, medroxyprogesterone and tamoxifen treatment in vitro.

OBJECTIVE: Autophagy is a form of physiological programmed cell death which is observable after hormonal withdrawal. In this study, the FM3A murine breast tumor cell line was treated with epirubicin alone and with medroxyprogesterone acetate (MPA) or tamoxifen, to determine if structural and kinetic signs of autophagy may also occur in an enhanced manner during epirubicin sensitization via hormonal agents. METHODS: One-week soft agar colony growth, 96-hour values of plating and pulse thymidine labeling and electron microscopical examinations were performed following treatment with MPA and tamoxifen alone or with epirubicin. RESULTS: Tamoxifen induced signs of autophagy, which was enhanced when it was combined with MPA. Epirubicin also induced autophagy of secretory granules, which coalesced to form an intracytoplasmic lumen. Combining MPA with epirubicin enhanced the formation of apoptotic blebs and chromatin fragmentation. When epirubicin was combined with tamoxifen, peculiar nuclear structures were formed. CONCLUSIONS: Hormonal agents may modulate anthracycline activity towards specific patterns in eliciting cell death, via autophagy and/or as yet unknown nucleolus-specific interactions.