Differential effect of the duration of exposure on the carcinogenicity of cadmium in MCF10A mammary epithelial cells

The carcinogenic role of cadmium (Cd2+) in breast cancer is still debatable. Current data points to duration of exposure as the most important element. In our study, we designed an in vitro model to investigate the effects of 3 weeks versus 6 weeks of low-level CdCl2 exposure on MCF10A cells. Our results demonstrated that after 3 weeks of CdCl2 exposure the cells displayed significant changes in the DNA integrity, but there was no development of malignant features. Interestingly, after 6 weeks of exposure, the cells significantly increased their invasion, migration and colony formation capacities. Additionally, MCF10A cells exposed for 6 weeks to CdCl2 had many dysregulated genes (4905 up-regulated and 4262 down-regulated). As follows, Cd-induced phenotypical changes are accompanied by a profound modification of the transcriptomic landscape. Furthermore, the molecular alterations driving carcinogenesis in MCF10A cells exposed to CdCl2 were found to be influenced by the duration of exposure, as in the case of MEG8. This long non-coding RNA was down-regulated at 3 weeks, but up-regulated at 6 weeks of exposure. In conclusion, even very low levels of Cd (0.5 μM) can have significant carcinogenic effects on breast cells in the case of subchronic exposure.

Meta-analyses reveal serum or plasma Interleukin-6 as a biomarker for malignant ovarian neoplasia

BACKGROUND

Interleukin-6 (IL-6) has been implicated in various malignancies, including ovarian cancer. However, mixed results have been observed regarding IL-6 levels in different ovarian conditions. This meta-analysis was performed to determine IL-6 levels in the peritoneal fluid and peripheral blood among patients with various adnexal masses.

METHODS

Most popular English databases were searched using a predefined search formula. All studies comparing IL-6 levels in plasma, serum or peritoneal fluid of patients with benign tumors, ovarian neoplasms, and healthy controls were included based on inclusion and exclusion criteria.

RESULTS

5953 patients from 22 primary publications raging from 1994 to 2021 were included in the meta-analyses. A pooled IL-6 Mean Difference (MD) of 41 pg/mL for malignant tumors compared to benign ones, with a Confidence Interval (CI) between 19.8 and 62.2, a Z-score of 3.79, and statistical significance with a p = 0.0002 was observed. Pooled results for healthy versus benign ovarian conditions showed an MD of 5.45 pg/mL for serum or plasma IL-6 measurements in favor of benign tumors (CI:0.66-10.25, Z = 2.23 and p = 0.03). The analysis showed an MD for IL-6 levels of 19.59 pg/mL for healthy controls versus malignant ovarian tumors. Peritoneal fluid measurements regarding IL-6's levels showed no significant difference between benign or malignant masses.

DISCUSSION/CONCLUSIONS

Higher levels of plasma or serum IL-6 in ovarian neoplasia patients compared to benign conditions or healthy controls identify IL-6 as a discerning factor between benign or malignant ovarian tumors and a potential biomarker for ovarian malignancy.

Facile Microwave Assisted Synthesis of Silver Nanostars for Ultrasensitive Detection of Biological Analytes by SERS

We report a very simple, rapid and reproducible method for the fabrication of anisotropic silver nanostars (AgNS) that can be successfully used as highly efficient SERS substrates for different bioanalytes, even in the case of a near-infra-red (NIR) excitation laser. The nanostars have been synthesized using the chemical reduction of Ag+ ions by trisodium citrate. This is the first research reporting the synthesis of AgNS using only trisodium citrate as a reducing and stabilizing agent. The key elements of this original synthesis procedure are rapid hydrothermal synthesis of silver nanostars followed by a cooling down procedure by immersion in a water bath. The synthesis was performed in a sealed bottom flask homogenously heated and brought to a boil in a microwave oven. After 60 s, the colloidal solution was cooled down to room temperature by immersion in a water bath at 35 °C. The as-synthesized AgNS were washed by centrifugation and used for SERS analysis of test molecules (methylene blue) as well as biological analytes: pharmaceutical compounds with various Raman cross sections (doxorubicin, atenolol & metoprolol), cell lysates and amino acids (methionine & cysteine). UV-Vis absorption spectroscopy, (Scanning) Transmission Electron Microscopy ((S)TEM) and Atomic Force Microscopy (AFM) have been employed for investigating nanostars' physical properties.

A comparative study of genotoxicity endpoints for women exposed to different levels of indoor radon concentrations

BACKGROUND AND PURPOSE

Radon and its radioactive progenies are the most important source of ionizing radiation of natural origin, being classified as a Group 1 carcinogen. The aim of this study is to investigate the genotoxic effects of a wide range of indoor radon concentrations, as well as the kinetics of the process of repairing DNA-induced lesions by a challenging dose of gamma irradiation.

MATERIAL AND METHODS

Female subjects residing in the Băiţa-Ştei radon priority area were selected as the exposed group. The reference group was comprised of women from the same county (Bihor), but located in an area with an average indoor radon concentration typical of the county from which they were taken. Radon concentration values of 300 Bq/m³ and 148 Bq/m³, respectively, were chosen as a threshold in order to capture the impact of radon exposure between the groups. The alkaline comet assay was used in order to measure the DNA damage, as well as the repair kinetics at 2 and 24 h after 2 Gy challenging doses of gamma irradiation using peripheral blood lymphocytes. From the serum of the subjects, the oxidative damage by 8-hydroxydeoxyguanosine as well as the PARP induction was evaluated. The chromosomal aberrations were evaluated using the Cytokinesis Block MicroNucleus Assay.

RESULTS

A statistically significant increase was observed in terms of DNA-induced lesions assessed by comet assay for the exposed group compared to the reference group. A positive correlation was obtained between DNA damage and the annual effective dose, respectively with the radon progenies concentrations. A statistically significant difference was also observed for the frequency of the micronuclei between the exposed - reference groups. Significantly faster repair kinetics of DNA-induced lesions was recorded for the first 2 h after gamma irradiation in the reference group compared to the exposed group. Using the threshold of 300 Bq/m³ for radon concentration, faster kinetics of DNA damage repair for people exposed to low radon concentrations, compared to those exposed to higher concentrations for the second phase of DNA repair kinetics was observed.

CONCLUSION

An increased radiosensitivity of lymphocytes, as well as slower repair kinetics, may be associated with exposure to higher indoor radon concentrations.

Evaluation of Antiproliferative Palladium(II) Complexes of Synthetic Bisdemethoxycurcumin towards In Vitro Cytotoxicity and Molecular Docking on DNA Sequence

Metallodrugs form a large family of therapeutic agents against cancer, among which is cisplatin, a paradigmatic member. Therapeutic resistance and undesired side effects to Pt(II) related drugs, prompts research on different metal-ligand combinations with potentially enhanced biological activity. We present the synthesis and biological tests of novel palladium(II) complexes containing bisdemethoxycurcumin (BDMC) 1 and 2. Complexes were fully characterized and their structures were determined by X-ray diffraction. Their biological activity was assessed for several selected human tumor cell lines: Jurkat (human leukaemic T-cell lymphoma), HCT-116 (human colorectal carcinoma), HeLa (human cervix epitheloid carcinoma), MCF-7 (human breast adenocarcinoma), MDA-MB-231 (human mammary gland adenocarcinoma), A549 (human alveolar adenocarcinoma), Caco-2 (human colorectal carcinoma), and for non-cancerous 3T3 cells (murine fibroblasts). The cytotoxicity of 1 is comparable to that of cisplatin, and superior to that of 2 in all cell lines. It is a correlation between IC50 values of 1 and 2 in the eight studied cell types, promising a potential use as anti-proliferative drugs. Moreover, for Jurkat cell line, complexes 1 and 2, show an enhanced activity. DFT and docking calculations on the NF-κB protein, Human Serum Albumin (HSA), and DNA were performed for 1 and 2 to correlate with their biological activities.

Celecoxib as a Valuable Adjuvant in Cutaneous Melanoma Treated with Trametinib

BACKGROUND

Melanoma patients stop responding to targeted therapies mainly due to mitogen activated protein kinase (MAPK) pathway re-activation, phosphoinositide 3 kinase/the mechanistic target of rapamycin (PI3K/mTOR) pathway activation or stromal cell influence. The future of melanoma treatment lies in combinational approaches. To address this, our in vitro study evaluated if lower concentrations of Celecoxib (IC50 in nM range) could still preserve the chemopreventive effect on melanoma cells treated with trametinib.

MATERIALS AND METHODS

All experiments were conducted on SK-MEL-28 human melanoma cells and BJ human fibroblasts, used as co-culture. Co-culture cells were subjected to a celecoxib and trametinib drug combination for 72 h. We focused on the evaluation of cell death mechanisms, melanogenesis, angiogenesis, inflammation and resistance pathways.

RESULTS

Low-dose celecoxib significantly enhanced the melanoma response to trametinib. The therapeutic combination reduced nuclear transcription factor (NF)-kB (p < 0.0001) and caspase-8/caspase-3 activation (p < 0.0001), inhibited microphthalmia transcription factor (MITF) and tyrosinase (p < 0.05) expression and strongly down-regulated the phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling pathway more significantly than the control or trametinib group (p < 0.0001).

CONCLUSION

Low concentrations of celecoxib (IC50 in nM range) sufficed to exert antineoplastic capabilities and enhanced the therapeutic response of metastatic melanoma treated with trametinib.

Phytochemical Analysis and In Vitro Effects of Allium fistulosum L. and Allium sativum L. Extracts on Human Normal and Tumor Cell Lines: A Comparative Study

Allium sativum L. (garlic bulbs) and Allium fistulosum L. (Welsh onion leaves) showed quantitative differences of identified compounds: allicin and alliin (380 µg/mL and 1410 µg/mL in garlic; 20 µg/mL and 145 µg/mL in Welsh onion), and the phenolic compounds (chlorogenic acid, p-coumaric acid, ferulic acid, gentisic acid, 4-hydroxybenzoic acid, kaempferol, isoquercitrin, quercitrin, quercetin, and rutin). The chemical composition determined the inhibitory activity of Allium extracts in a dose-dependent manner, on human normal cells (BJ-IC₅₀ 0.8841% garlic/0.2433% Welsh onion and HaCaT-IC₅₀ 1.086% garlic/0.6197% Welsh onion) and tumor cells (DLD-1-IC₅₀ 5.482%/2.124%; MDA-MB-231-IC₅₀ 6.375%/2.464%; MCF-7-IC₅₀ 6.131%/3.353%; and SK-MES-1-IC₅₀ 4.651%/5.819%). At high concentrations, the cytotoxic activity of each extract, on normal cells, was confirmed by: the 50% of the growth inhibition concentration (IC₅₀₎ value, the cell death induced by necrosis, and biochemical determination of LDH, catalase, and Caspase-3. The four tumor cell lines treated with high concentrations (10%, 5%, 2.5%, and 1.25%) of garlic extract showed different sensibility, appreciated on the base of IC₅₀ value for the most sensitive cell line (SK-MES-1), and the less sensitive (MDA-MB-231) cell line. The high concentrations of Welsh onion extract (5%, 2.5%, and 1.25%) induced pH changes in the culture medium and SK-MES-1 being the less sensitive cell line.

Role of Folic Acid in the Therapeutic Action of Nanostructured Porous Silica Functionalized with Organotin(IV) Compounds Against Different Cancer Cell Lines

The synthesis, characterization and cytotoxic activity against different cancer cell lines of various mesoporous silica-based materials containing folate targeting moieties and a cytotoxic fragment based on a triphenyltin(IV) derivative have been studied. Two different mesoporous nanostructured silica systems have been used: firstly, micronic silica particles of the MSU-2 type and, secondly, mesoporous silica nanoparticles (MSNs) of about 80 nm. Both series of materials have been characterized by different methods, such as powder X-ray diffraction, X-ray fluorescence, absorption spectroscopy and microscopy. In addition, these systems have been tested against four different cancer cell lines, namely, OVCAR-3, DLD-1, A2780 and A431, in order to observe if the size of the silica-based systems and the quantity of incorporated folic acid influence their cytotoxic action. The results show that the materials are more active when the quantity of folic acid is higher, especially in those cells that overexpress folate receptors such as OVCAR-3 and DLD-1. In addition, the study of the potential modulation of the soluble folate receptor alpha (FOLR1) by treatment with the synthesized materials has been carried out using OVCAR-3, DLD-1, A2780 and A431 tumour cell lines. The results show that a relatively high concentration of folic acid functionalization of the nanostructured silica together with the incorporation of the cytotoxic tin fragment leads to an increase in the quantity of the soluble FOLR1 secreted by the tumour cells. In addition, the studies reported here show that this increase of the soluble FOLR1 occurs presumably by cutting the glycosyl-phosphatidylinositol anchor of membrane FR-α and by the release of intracellular FR-α. This study validates the potential use of a combination of mesoporous silica materials co-functionalized with folate targeting molecules and an organotin(IV) drug as a strategy for the therapeutic treatment of several cancer cells overexpressing folate receptors.

Excess Ascorbate is a Chemical Stress Agent against Proteins and Cells

Excess ascorbate (as expected in intravenous treatment proposed for COVID-19 management, for example) oxidizes and/or degrades hemoglobin and albumin, as evidenced by UV-vis spectroscopy, gel electrophoresis, and mass spectrometry. It also degrades hemoglobin in intact blood or in isolated erythrocytes. The survival rates and metabolic activities of several leukocyte subsets implicated in the antiviral cellular immune response are also affected. Excess ascorbate is thus an unselective biological stress agent.

Novel Phenothiazine-Bridged Porphyrin-(Hetero)aryl dyads: Synthesis, Optical Properties, In Vitro Cytotoxicity and Staining of Human Ovarian Tumor Cell Lines

We report here the synthetic procedure applied for the preparation of new AB₃-type and trans-A₂B₂ type meso-halogenophenothiazinyl-phenyl-porphyrin derivatives, their metal core complexation and their peripheral modification using Suzuki-Miyaura cross coupling reactions with various (hetero)aryl (phenothiazinyl, 7-formyl-phenothiazinyl, (9-carbazolyl)-phenyl and 4-formyl-phenyl, phenyl) boronic acid derivatives. The meso-phenothiazinyl-phenyl-porphyrin (MPP) dyes family was thus extended by a series of novel phenothiazine-bridged porphyrin-(hetero)aryl dyads characterized by UV-Vis absorption/emission properties typical to the porphyrin chromophore, slightly modulated by increasing the size of peripheral substituents. Three phenothiazine-bridged porphyrin-heteroaryl dyads with fluorescence emission above 655 nm were selected as fluorophores in red spectral region for applications in cellular staining of human ovarian tumors. In vitro experiments of cell metabolic activity displayed a moderate toxicity on human ovarian tumor cell lines (OVCAR-3, cisplatin-sensitive A2780 and cisplatin-resistant A2780cis respectively). Visualization of the stained living cells was performed both by fluorescence microscopy imaging and by fluorescence lifetime imaging under two photon excitation (TPE-FLIM), confirming their cellular uptake and the capability of staining the cell nucleus.

The Synergistic Antitumor Effect of 5-Fluorouracil Combined with Allicin against Lung and Colorectal Carcinoma Cells

5-fluorouracil (5-FU) is an anticancer drug used to inhibit the proliferation of many different tumor cells. Since severe events are associated with this compound, its combination with different anticancer drugs or adjuvants would allow the use of a significantly lower dose of 5-FU. In this study, we highlighted that the combination of allicin with 5-FU inhibited the cell migration and proliferation of colorectal and lung cancer cells. 5-FU inhibited cell growth with a similar inhibitory concentration for both normal and tumor cells (~200µM), while allicin showed different inhibitory concentrations. With an IC50 of 8.625 µM, lung cancer cells were the most sensitive to allicin. Compared to 5-FU and allicin single-agent treatments, the co-treatment showed a reduced viability rate, with p < 0.05. The morphological changes were visible on all three cell lines, indicating that the treatment inhibited the proliferation of both normal and tumor cells. We highlighted different cell death mechanisms—apoptosis for lung cancer and a non-apoptotic cell death for colorectal cancer. The synergistic antitumor effect of 5-FU combined with allicin was visible against lung and colorectal carcinoma cells. Better results were obtained when a lower concentration of 5-FU was combined with allicin than the single-agent treatment at IC50.

The expression of copper transporters associated with the ototoxicity induced by platinum-based chemotherapeutic agents

BACKGROUND

Antitumor agents based on platinum have gained a well-established place in the treatment of several forms of cancer. Their efficiency is hampered by serious toxic effects against healthy tissues as well. Ototoxicity is a serious side effect leading to hearing impairment and represents an important issue affecting the patients' quality of life. The currently used platinum chemotherapeutics exert different toxicity towards cochlear cells. The aim of our study was to answer some questions regarding the differential uptake and cellular pharmacodynamics of Cisplatin (CDDP), Carboplatin (CBDCA) and Oxaliplatin (L-OHP) in the HEI-OC1 cochlear cell line.

METHODS

We studied the expression of copper transporters CTR1, ATP7A and ATP7B which are presumably involved in the uptake, cellular transport and efflux of platinum compounds by immunofluorescence microscopy and flow-cytometry. The cellular uptake of the compounds was evaluated through the determination of intracellular platinum concentration by atomic absorption spectroscopy. The effects of the treatment of HEI-OC1 cells with platinum compounds were also evaluated: cytotoxicity with the Cell Titer Blue viability test, formation of reactive oxygen species with 2',7' -dichlorofluorescein diacetate, genotoxicity with the comet assay and apoptosis with the cleaved PARP ELISA test.

RESULTS

CTR1, ATP7A and ATP7B were all expressed by HEI-OC1 cells. The treatment with the platinum compounds led to a modulation of their expression, manifested in a differential platinum uptake. Treatment with Cisplatin led to the highest intracellular concentration of platinum compared to Oxaliplatin and Carboplatin at the same dose. Treatment with CuSO4 reduced platinum uptake of all the compounds, significantly in the case of Cisplatin and Carboplatin. CDDP was the most cytotoxic against HEI-OC1 cells, with an IC50 = 65.79  μM, compared to 611.7 μM for L-OHP and 882.9 μM for CBDCA, at the same molar concentration. The production of ROS was the most intense after CDDP, followed by L-OHP and CBDCA. In the comet assay, at the 100 μM concentration, L-OHP and CBDCA induced DNA adducts while CDDP induced adducts as well as DNA strand breaks. CBDCA and L-OHP lead to a significant increase of cleaved PARP at 24h (p < 0.001), suggesting an important apoptotic process induced by these compounds at the used concentrations.

CONCLUSIONS

The results obtained in the current study suggest that the modulation of copper transporters locally may represent a new strategy against platinum drugs ototoxicity.

Modulatory effect of curcumin analogs on the activation of metalloproteinases in human periodontal stem cells

Periodontitis progresses due to increased levels of active metalloproteinases (MMPs) and the imbalance between MMPs and their tissue inhibitors (TIMPs). Natural curcumin limits the lytic activity of MMPs but has low cellular uptake. Use of synthetic curcumin analogs could be a means of overcoming this limitation of treatment efficiency. Human periodontal stem cells were isolated from gingival tissue, gingival ligament fibers, periodontal ligament, and alveolar bone. The effect of five synthetic curcumin analogs was compared with that of natural curcumin by assessing cytotoxicity [by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay], the cellular uptake (by fluorometry), the proteolytic activities of MMP-2 and -9 (by zymography), and the levels of TIMP-1 (by ELISA). Our results indicated increased cytotoxicity of synthetic curcumins for doses between 100 and 250 μM. At a concentration of 10 μM, cellular uptake of synthetic curcumins varied depending on their chemical structure. The curcumin compounds modulated pro-MMP-2 levels and increased TIMP-1 production. There was no detectable synthesis of pro-MMP-9 and no activation of MMPs 2 and 9. Gingival tissue and gingival ligament fiber stem cells were most responsive to treatment, showing inverse correlations between pro-MMP-2 and TIMP-1 levels. In conclusion, synthetic curcumins influenced the balance between pro-MMP-2 and TIMP-1 in human periodontal stem cells in vitro, and this could open perspectives for their application as adjuvants in periodontal therapy.

Combined effect of propranolol, vincristine and bevacizumab on HUVECs and BJ cells

Infantile hemangioma is one of the most common benign tumors affecting children, with ~10-15% requiring medical treatment. These tumors consist of endothelial cells and stromal components, including fibroblasts, pericytes and mast cells. Effects of propranolol treatment in combination with bevacizumab or vincristine on cell growth were compared in the current study using human umbilical vein endothelial cells (HUVECs) and BJ human normal fibroblasts (BJs) to determine potential synergic effects in vitro. Inhibition of cell growth was investigated using MTT assays and cytotoxicity of the drugs in various combinations was expressed as half inhibitory concentration (IC₅₀). Apoptosis was investigated using flow cytometry, with Alexa Fluor 488 and propidium iodide. Propranolol inhibited BJ and HUVEC growth in a dose-dependent manner, with increased response observed in BJs (IC50, 148,32 µg/ml; standard error logIC50, 0.07). Treatment with vincristine induced the strongest growth inhibition in HUVECs (IC50, 17,89 µg/ml; standard error log IC50, 0.07) and BJs (IC50, 24,81 µg/ml; standard error log IC50, 0.08) compared with propranolol (HUVEC IC50, 81,94 µg/ml; standard error log IC50, 0.06; BJ-IC50, 148,32 µg/ml; standard error logIC50, 0.07) or bevacizumab (HUVEC IC50 96,91 µg/ml; standard error log IC50, 0.06; BJ IC50, 182,70 µg/ml; standard error log IC50, 0.09) alone. Bevacizumab was the weakest cytotoxic agent. Combination treatment of vincristine with bevacizumab induced the highest levels of apoptosis in HUVECs compared with all other treatments and triple-drug therapy induced the levels of apoptosis in BJs. Single treatment with vincristine, propranolol or bevacizumab induced apoptosis in BJs and HUVECs. In BJs, triple treatment exhibited the greatest influence on apoptosis, compared with single and dual treatments and in HUVECs, vincristine and bevacizumab combination treatment induced apoptosis to the highest level. The present study offers novel perspectives in drug repurposing studies for the three drugs, particularly in diseases where the pathogenesis is based on healthy endothelial cell proliferation, including hemangiomas.

Modulation of the mechanism of apoptosis in cancer cell lines by treatment with silica-based nanostructured materials functionalized with different metallodrugs

The mesoporous silica-based material SBA-15 (Santa Barbara Amorphous-15) has been modified with the aminodiol ligand 3-[bis(2-hydroxyethyl)amino]propyltriethoxysilane (PADOH) to give the corresponding material SBA-PADOH. Subsequent functionalization with a diorganotin(iv) compound, SnPh2Cl2 (1), and with two titanocene derivatives, TiCp2Cl2 ([Ti(η5-C5H5)2Cl2] (2)) and TiCpCpPhNfCl2 ([Ti(η5-C5H5)(η5-C5H4CHPhNf)Cl2] (3) (Ph = C6H5; Nf = C10H7)), gave the materials SBA-PADO-SnPh2 (M1), SBA-PADO-TiCp2 (M2) and SBA-PADO-TiCpCp* (M3), respectively. SBA-PADOH and M1-M3 have been characterized by various techniques such as FT-IR, XRD, XRF, solid-state NMR, nitrogen adsorption-desorption isotherms, electrochemical methods, SEM and TEM, observing that the functionalization has mainly taken place inside the pores of the corresponding porous system. In addition, mechanistic aspects of the apoptosis triggered by the synthesized materials have been studied in vitro in tumour cell lines derived from three distinct types of cancer in order to elucidate their growth inhibition and interference with the expression of tumour necrosis factor alfa (TNF-α) and the first apoptosis signal receptor (Fas or tumour necrosis factor receptor 6). It was observed that the antiproliferative and proapoptotic capacity of the materials depends on their functionalization with the different cytotoxic prodrugs (organotin or titanocene derivatives). The study shows that M1-M3 influence the metabolic activity of the tumour cells and modulate the apoptotic pathways by different mechanisms, according to the active compound inside the material.

Targeting MAPK (p38, ERK, JNK) and inflammatory CK (GDF-15, GM-CSF) in UVB-Activated Human Skin Cells with Vitis vinifera Seed Extract

Ultraviolet B radiation (UVB) activates mitogen-activated protein kinases (MAPK): p38, extracellular signal regulated (ERK), and c-Jun N-terminal (JNK) kinases in human skin cells. Human keratinocytes (KC) exposed to UVB secrete several cytokines (CK), among which the growth differentiation factor-15 (GDF-15) is augmented in inflammatory and aging processes and the granulocyte macrophage-colony stimulating factor (GM-CSF) is involved in cell proliferation, differentiation, and survival, and both CK have implications in skin carcinogenesis. We assessed p38, ERK, JNK, GDF-15, and GM-CSF in UVB-exposed skin cells and a red grape (Vitis vinifera) seed extract's (GSE) capacities to regulate these pathways in UVB-exposed KC. Two concentrations of the GSE extract were selected: GSE1 (37.5 μgEqGA/mL) and GSE2 (75 μgEqGA/mL) and a UVB dose (100 mJ/cm2) within the physiological range. Molecules were assessed with ELISA, semiquantitative results being confirmed by Western blot. UVB triggered the signaling molecules' phosphorylation and the concentrations of CK. All molecules but GM-CSF increased early, at 2 h, from UVB exposure while GM-CSF increased later (at 8 h). MAPK and GDF-15 were regulated by GSE1; GM-CSF, by the higher concentration, GSE2. The amplitude and kinetics of the responses were diverse according to time point, molecules, and the extract's concentration. GSE exerted beneficial effects on MAPK and CK triggered by UVB in human skin cells: reduction of phosphorylation of the assessed signaling molecules and anti-inflammatory effects. Targeting MAPK and specific inflammatory mediators such as GDF-15 and GM-CSF with GSE in UVB-induced skin cells represents a novel and a promising starting point for future photoprotection strategies.

Exosomes at a glance - common nominators for cancer hallmarks and novel diagnosis tools

Cancer represents a heterogeneous disease with multiple levels of regulation and a dynamic environment that sustains the evolution of the malignant mass. This dynamic is in part sustained by a class of extracellular vesicles termed exosomes that are able to imprint the pathological state by incorporating differential cargos in order to facilitate cell-to-cell communication. Exosomes are stable within the extracellular medium and function as shuttles secreted by healthy or pathological cells, being further taken by the accepting cell with direct effects on its phenotype. The exosomal trafficking is deeply involved in multiple levels of cancer development with roles in all cancer hallmarks. Nowadays, studies are constantly exploring the ability of exosomes to sustain the malignant progression in order to attack this pathological trafficking and impair the ability of the tumor mass to expand within the organisms. As important, the circulatory characteristics of exosomes represent a steady advantage regarding the possibility of using them as minimally invasive diagnosis tools, where cancer patients' present modified exosomal profiles compared to the healthy ones. This last characteristic, as novel diagnosis tools, has the advantage of a possible rapid transition within the clinic, compared to the studies that evaluate the therapeutic meaning.

Low-dose radiations derived from cone-beam CT induce transient DNA damage and persistent inflammatory reactions in stem cells from deciduous teeth

OBJECTIVES

Cone-beam CT (CBCT), a radiographic tool for diagnosis, treatment, and follow-up in dental practice, was introduced also in pediatric radiology, especially orthodontics. Such patients subjected to repetitive X-rays examinations may receive substantial levels of radiation doses. Ionizing radiation (IR), a recognized carcinogenic factor causing DNA double-strand breaks (DSBs) could be harmful to undifferentiated cells such as dental pulp stem cells (DPSCs) since inaccurately repaired or unrepaired DSBs may lead to malignant transformation. The H2AX and MRE11 proteins generated following DSBs formation and pro-inflammatory cytokines (CKs) secreted after irradiation are relevant candidates to monitor the cellular responses induced by CBCT.

METHODS

DPSCs were extracted from human exfoliated deciduous teeth and their phenotype was assessed by immunocytochemistry and flow-cytometry. Cells were exposed to IR doses: 5.4-107.7 mGy, corresponding to 0.5-8 consecutive skull exposures, respectively. H2AX and MRE11 were detected in whole cells, while IL-1α, IL-6, IL-8, TNFα in supernatants, using enzyme-linked immunosorbent assay (ELISA) at different time points after exposure.

RESULTS

The phosphorylation level of H2AX in DPSCs increased considerably at 0.5 h after exposure (p < 0.001 for 3, 5, 8 skull exposures and p < 0.05 for 1 skull exposure, respectively). MRE11 response could only be detected for the highest IR dose (p < 0.001) in the same interval. CKs secretion increased upon CBCT exposure according to doses and time.

CONCLUSIONS

The DPSCs exposure to CBCT induces transient DNA damage and persistent inflammatory reaction in DPSCs drawing the attention on the potential risks of IR exposures and on the importance of dose monitoring in pediatric population.

In vitro and in vivo anti-inflammatory properties of green synthesized silver nanoparticles using Viburnum opulus L. fruits extract

A green, rapid and cost effective method for the bio-synthesis of silver nanoparticles (AgNPs), using polyphenols present in European cranberry bush fruit extracts was developed. The obtained AgNPs were characterized by ultra-violet visible spectroscopy (UV-VIS), Fourier transform - infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and X-ray diffraction patterns (XRD). The average size of the spherical AgNPs was found to be 25nm. The anti-inflammatory effect of the biomaterials was investigated, both in vitro (on HaCaT cell line, exposed to UVB radiation) and in vivo (on acute inflammation model in Wistar rats). Our results support the conclusion that the photosynthesized silver nanoparticles present a potent anti-inflammatory activity and could be successfully used as therapeutic tools for treatment of inflammation.

Platinum derivatives: a multidisciplinary approach

Cancer is one of the most difficult diseases to be treated. The particularities regarding the tumors' occurrence mechanism, their evolution under chemotherapy, disease-free interval, but also the increasing number of patients make cancer an intensively studied health domain. Although introduced in therapy since the early 80s, platinum derivatives play an essential role in anticancer therapy. Their use in therapy resulted in improving the patient quality of life and prolonging disease-free interval, which makes them still a benchmark for other anticancer compounds. However, adverse reactions and allergic reactions are a major impediment in therapy with platinum derivatives. This paper summarizes data about platinum derivatives through a multidisciplinary approach, starting from a chemical point of view and on to their mechanism of action, mechanism of cellular resistance, predictive factors for the outcome of chemotherapy such as micro RNAs (miRNAs), tumor suppressor protein p53, and the excision repair cross-complementing 1 protein (ERCC1).

Vitis vinifera seeds extract for the modulation of cytosolic factors BAX-α and NF-kB involved in UVB-induced oxidative stress and apoptosis of human skin cells

Background and aims

The depletion of the ozone layer allows overexposure of the skin to UV radiation, which is prolonged due to the increasing life expectancy, together with inappropriate life habits contribute to the increasing incidence of cutaneous malignancies. Plant extracts with antioxidant capacities are frequently employed as a means to protect skin against ultraviolet (UV) radiations, thus preventing skin cancers. In the present study we assessed a red grape seed extract (GSE) potential capacities to reduce ultraviolet B (UVB) radiation-induced reactive oxygen species (ROS) and subsequent apoptosis in a human keratinocytes cell line (HaCaT). We identified molecules and pathways modulated by the GSE through which this may exert its photoprotective effect.

Methods

The GSE was standardized according to its polyphenolic content and the most important biologically active compounds, such as epigallocatechin and epicatechin, catechin hydrate, procyanidin B and gallic acid were evidenced by high-performance liquid chromatography. According to the plant extract cytotoxicity on the HaCaT cell line, two concentrations were selected for testing from the non-toxic range: GSE₁ (37.5 μgEqGA/ml) and GSE₂ (75 μgEqGA/ml). The level of ROS was evaluated with CM-H₂DCFDA assay, while apoptosis, Bax-α and NF-kβ p65 proteins with ELISA and confirmed by western-blot.

Results

Both concentrations of the extract decreased the level of ROS in UVB-irradiated keratinocytes (p<0.001), whereas apoptosis and Bax-α pro-apoptotic protein were only reduced by the higher concentration (GSE₂). The NF-kB p65 protein level registered increasing values in time after UVB exposure of the cells, while the tested plant extract re-established its level when its smaller concentration was used (GSE₁).

Conclusion

These results encourage further studies on this extract in order to identify other molecules and pathways through which this extract might exert its beneficial effects and also recommend its use as a potential photoprotective agent.

Iron, inflammation and invasion of cancer cells

Chronic inflammation is associated with the metastasis of tumor cells evolving from a benign tumor to disseminating cancer. Such a metastatic progression is fostered by the angiogenesis propelled by various mediators interacting at the site of tumor growth. Angiogenesis causes two major changes that are assisted by altered glycosylation and neo-antigen presentation by the cancer cells. The angiogenesis-promoted pathological changes include enhanced inflammation and degradation of tissue matrices releasing tumor cells from the site of its origin. The degraded tumor cells release the neo-antigens resulting from altered glycosylation. Presentation of neo-antigens to T cells escalates metastasis and inflammation. Inflammasome activation and inflammation in several infections are regulated by iron. Based on the discrete reports, we propose a link between iron, inflammation, angiogenesis and tumor growth. Knowing the link better may help us formulate a novel strategy for cancer immunotherapy.

Gallium phosphinoarylbisthiolato complexes counteract drug resistance of cancer cells

In cancer therapy the platinum-based drugs are used frequently with a good clinical outcome, but besides unwanted side effects which occur, the tumour cells subjected to treatment are prone to develop tolerance or even multidrug resistance (MDR). Metal compounds with a central atom other than platinum are efficient in targeting the chemoresistant cells, therefore the biological outcome of two recently synthesized gallium phosphinoarylbisthiolato complexes was studied, having the formula [X][Ga{PPh(2-SC6H4)2-κ(3)S,S',P}{PPh(2-SC6H4)2-κ(2)S,S'}] where [X] is either the NEt3H (1) or PPh4 (2) cation. Compounds 1 and 2 display in vitro cytotoxicity against both platinum-sensitive and platinum-resistant cell lines (A2780 and A2780cis). Morphological and ultrastructural evidence points toward their capacity to impair tumour cells survival. This behaviour is based on malignant cells capacity to selectively intake gallium, and to bind to the cellular DNA. They are able to cause massive DNA damage in treated cancer cells, focusing on 7-methylguanine and 8-oxoguanine sites and oxidizing the pyrimidine bases; this leads to early apoptosis of a significant percent of treated cells. The intrinsic and extrinsic apoptotic pathways are influenced through the modulation of gene expression following the treatment with complexes 1 and 2, which accompanies the negative regulation of P-glycoprotein 1 (Pgp-1), an important cellular ABC-type transporter from the multidrug resistance (MDR) family. The studied Ga(III) compounds demonstrated the capacity to counteract the chemoresistance mechanisms in the tumours defiant to standard drug action. Compound 2 shows a good anticancer potential and it could represent an alternative to platinum-based drugs especially in the situation of standard treatment failure.

Green synthesis, characterization and anti-inflammatory activity of silver nanoparticles using European black elderberry fruits extract

This research aimed at reporting the synthesis, characterization and evaluation of the anti-inflammatory effects of some new biomaterials based on silver nanoparticles and polyphenols rich natural extracts. A fast and eco-friendly extracellular biosynthesis of silver nanoparticles (AgNPs), using European black elderberry (Sambucus nigra - SN, Adoxaceae family) fruit extracts was developed. The phytosynthesized nanoparticles exhibited an absorbance peak at 426nm, characteristic for AgNPs and their sizes were ranged from 20 to 80nm. The anti-inflammatory properties of AgNPs were assessed in vitro on HaCaT cells exposed to UVB radiation, in vivo on acute inflammation model and in humans on psoriasis lesions. In vitro, our results demonstrated the anti-inflammatory effects of functionalized AgNPs by the decrease of cytokines production induced by UVB irradiation. In vivo, the pre-administration of AgNPs reduced the edema and cytokines levels in the paw tissues, early after the induction of inflammation. The present study also demonstrated the possible use of synthesized AgNPs for the treatment of psoriasis lesions.

Oxidative protection of hemoglobin and hemerythrin by cross-linking with a nonheme iron peroxidase: potentially improved oxygen carriers for use in blood substitutes

The nonheme peroxidase, rubrerythrin, shows the ability to reduce hydrogen peroxide to water without involving strongly oxidizing and free-radical-creating powerful oxidants such as compounds I and II [formally Fe(IV)] formed in peroxidases and catalases. Rubrerythrin could, therefore, be a useful ingredient in protein-based artificial oxygen carriers. Here, we report that the oxygen-carrying proteins, hemoglobin (Hb) and hemerythrin (Hr), can each be copolymerized with rubrerythrin using glutaraldehyde yielding high molecular weight species. These copolymers show additional peroxidase activity compared to Hb-only and Hr-only polymers, respectively and also generate lower levels of free radicals in reactions that involve hydrogen peroxide. Tests on human umbilical vein endothelial cells (HUVEC) reveal slightly better performance of the Rbr copolymers compared to controls, as measured at 24 h, but not at later times.

Anti-cancer applications of titanocene-functionalised nanostructured systems: an insight into cell death mechanisms

A series of alkenyl-substituted titanocene compounds have been supported on the mesoporous silica-based material KIT-6. The corresponding functionalised materials were completely characterised by different techniques (solid-state multinuclear NMR spectroscopy, IR spectroscopy, N2 adsorption-desorption isotherms, X-ray fluorescence and diffraction, SEM and TEM) to observe the incorporation of the titanocene derivatives on the external surface of the material KIT-6. Both the titanocene compounds and the materials were tested in vitro against a wide variety of human cancer and normal cell lines. A very high cytotoxicity of the synthesised titanocene derivatives (IC50 values in the range of those described in the literature for the most active cytotoxic titanocene compounds), with selectivity towards cancer cell lines was observed. The cytotoxic activity of the materials is the highest reported to date for titanocene-functionalised materials. In addition, higher Ti uptake (from 4 to 23% of the initial amount of Ti) of the cells treated with materials was observed with respect to those treated with "free" titanocene derivatives (which gave Ti uptake values from 0.4 to 4.6% of the initial amount of Ti). Additional experiments with the titanocene derivatives and the functionalised materials revealed that changes to the morphological and functional dynamics of apoptosis occurred when the active titanocene species were incorporated into mesoporous materials. In addition, the materials could induce programmed cell death in tumour cell populations by impairing the damaged DNA repair mechanisms and by upregulation of intrinsic and extrinsic apoptotic signalling pathways.

Oxaliplatin induces different cellular and molecular chemoresistance patterns in colorectal cancer cell lines of identical origins

Background

Cancer cells frequently adopt cellular and molecular alterations and acquire resistance to cytostatic drugs. Chemotherapy with oxaliplatin is among the leading treatments for colorectal cancer with a response rate of 50%, inducing intrastrand cross-links on the DNA. Despite of this drug’s efficiency, resistance develops in nearly all metastatic patients. Chemoresistance being of crucial importance for the drug’s clinical efficiency this study aimed to contribute to the identification and description of some cellular and molecular alterations induced by prolonged oxaliplatin therapy. Resistance to oxaliplatin was induced in Colo320 (Colo320R) and HT-29 (HT-29R) colorectal adenocarcinoma cell lines by exposing the cells to increasing concentrations of the drug. Alterations in morphology, cytotoxicity, DNA cross-links formation and gene expression profiles were assessed in the parental and resistant variants with microscopy, MTT, alkaline comet and pangenomic microarray assays, respectively.

Results

Morphology analysis revealed epithelial-to-mesenchymal transition in the resistant vs parental cells suggesting alterations of the cells’ adhesion complexes, through which they acquire increased invasiveness and adherence. Cytotoxicity measurements demonstrated resistance to oxaliplatin in both cell lines; Colo320 being more sensitive than HT-29 to this drug (P < 0.001). The treatment with oxaliplatin caused major DNA cross-links in both parental cell lines; in Colo320R small amounts of DNA cross-links were still detectable, while in HT-29R not. We identified 441 differentially expressed genes in Colo320R and 613 in HT-29R as compared to their parental counterparts (at least 1.5 -fold up- or down- regulation, p < 0.05). More disrupted functions and pathways were detected in HT-29R cell line than in Colo320R, involving genes responsible for apoptosis inhibition, cellular proliferation and epithelial-to-mesenchymal transition. Several upstream regulators were detected as activated in HT-29R cell line, but not in Colo320R.

Conclusions

Our findings revealed a more resistant phenotype in HT-29R as compared to Colo320R and different cellular and molecular chemoresistance patterns induced by prolonged treatment with oxaliplatin in cell lines with identical origins (colorectal adenocarcinomas).

GITR-expressing regulatory T-cell subsets are increased in tumor-positive lymph nodes from advanced breast cancer patients as compared to tumor-negative lymph nodes

Lymph node (LN) infiltration by neoplastic process involves important changes in lymph node immune microenvironment. In particular, regulatory T cells (Treg) seem to have a key role in altering the immunoediting function of the immune system which leads to the elusion of the tumor from immune surveillance. In this study, we evaluated the expression of T-cell markers in CD4+ and CD8+ subsets from tumor-positive and tumor-negative lymph nodes from the same, advanced stage breast cancer patient. The study was carried out on 3 patients and similar results were obtained. Flow cytometric analysis of CD8+ cells demonstrated a significant difference in the expression of CD25, CD45RA, CD45RO, and GITRL (Glucocorticoid-Induced TNF receptor-Related ligand). Flowcytometric analysis of CD4+ cells demonstrated a significant difference in the expression of GITR (Glucocorticoid-Induced TNF receptor-Related), CD25, FoxP3 (Forkhead box P3), CD28, and CD45RA. Multiple staining allowed the identification of two Treg subpopulations, CD4+ CD25 highGITR+ CD127-/low and CD4+ CD25 low GITR+ CD127+ cells, proving that both are increased in the positive nodes in comparison with the negative nodes from the same patient. We identified for the first time the CD4+ CD25 low GITR+ CD127+ Treg subpopulation in cancer, and the 2.6 fold increase in positive LN suggests that this Treg subpopulation could be a key player in metastasis. We also found GITRL expression in the CD8 lymphocytes, which may also contribute to the changes of metastatic lymph node microenvironment. These findings make both GITR and GITRL good possible co-candidates for future therapeutical intervention against metastasis and perhaps also as disease evolution biomarkers.

Heterocycles 27. Microwave assisted synthesis and antitumour activity of novel phenothiazinyl-thiazolyl-hydrazine derivatives

A series of new phenothiazinyl-thiazolyl-hydrazine derivatives were synthesized by Hantzsch cyclization of 1-(10-ethyl-10H-phenothiazin-3-yl)-methylidene-thiosemicarbazide with α-halocarbonyl derivatives. Comparison between classical and microwave assisted synthesis emphasizes the great advantages induced by microwaves irradiation which afforded high reaction yields in much shorter reaction time. Structural assignments were based on spectroscopic methods (high resolution NMR, FTIR, MS). The new compounds were tested in vitro for their antiproliferative activity against tumor cell lines using spectrometric methods. Most of the compounds exhibit cytotoxicity against hepatic and colon tumor cells in a dose-dependent mode and a relationship between the structure and their biological activity was observed.

Photoprotective effect of Calluna vulgaris extract against UVB-induced phototoxicity in human immortalized keratinocytes

There is an increasing interest in the use of natural antioxidants as photoprotective agents against skin damages produced by ultraviolet radiation. The aim of our study was to investigate the protective effect of a Calluna vulgaris extract in human keratinocytes (HaCaT) exposed to ultraviolet B (UVB) radiation. HaCaT cells were treated with C. vulgaris extract 30 minutes prior to irradiation with UVB. The protective effect was evaluated by assessing cell viability using tetrasolium salt (MTT) assay; the generation of lipid peroxides was evaluated using malondialdehide assay (MDA); and DNA damage was evaluated using the comet assay and the quantification by ELISA of specific DNA photolesions [i.e., cyclobutane-pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs)]. After irradiation with cytotoxic doses of UVB (300 and 500 mJ/cm(2)), HaCaT cells pretreated with C. vulgaris extract (50 μg GAE/ml) showed significantly increased viability compared to control cells exposed to UVB only. Irradiation alone increased MDA levels in a dose-dependent fashion. Pretreatment with 12 μg GAE/ml extract lowered MDA levels both at 100 mJ/cm(2) (ρ<0.01) and 300 mJ/cm(2) (ρ<0.001). Treatment with C. vulgaris extract before exposure to UVB also reduced DNA damage: Lesion scores in a comet assay were significantly reduced at UVB doses of 50 mJ/cm2 (ρ<0.01) and 100 mJ/cm(2) (ρ<0.05), while CPDs and 6-4PPs (via ELISA) were significantly lower after irradiation with 100 mJ/cm(2) in the protected cells (ρ<0.05 for CPDs and ρ<0.001 for 6-4PPs). These results recommend the use of the C. vulgaris extract as photoprotective agent, in combination with sunscreens and/or other natural products with similar or complementary properties.

Antiproliferative effect of novel platinum(II) and palladium(II) complexes on hepatic tumor stem cells in vitro

Novel platinum and palladium complexes with (2-isopropoxyphenyl)dicyclohexylarsine and (2-methoxyphenyl)dicyclohexylarsine ligands were synthesized and tested on different tumor cells. Adducts with general formula MX(2)L(2) (M = Pt(II), Pd(II); X = Cl or I; L = organoarsenic ligand) were fully characterized. According to the crystallographic data, in all complexes the organoarsenic ligands coordinate the metal center through the arsenic atom only, in a trans arrangement with the halogen atoms. The antiproliferative potential of complexes 1-4 was evaluated in vitro on human tumor cell lines. A markedly biological activity was observed against the chemoresistant hepatic tumor stem cell line, the normal hepatic stem cells and towards the hepatocellular carcinoma (non-stem) cells. The new compounds toxicity is selectively limited in normal liver cells, unlikeness with the oxaliplatin, which displays a more intense effect in normal cells, compared with the two tumor cell lines. The stem cells treatment with compounds 1-4 causes DNA damages; the antimitotic effect of these compounds is based on their genotoxicity and on the capacity to form crosslinks with the DNA interstrand. In the case of platinum complexes 1 and 3 this mechanism gives rise to specific lesions on DNA that induces apoptosis in stem cells, influencing their selectivity in tumor cell growth inhibition. Compounds 1, 2 and 4 display higher activity against tumor stem cells. The novel platinum complexes 1 and 3 are more efficient against tumor stem cells than oxaliplatin, and if used in combination with sorafenib-based monoclonal anticancer therapy, complexes 1, 3 and 4 have the ability to induce superior chemosensitivity relative to sorafenib than the standard platinum-based drug, making them promising candidates for prodrug development.

Arsenic trioxide plus cisplatin/interferon α-2b/doxorubicin/capecitabine combination chemotherapy for unresectable hepatocellular carcinoma

BACKGROUND AND OBJECTIVES

The failure of existing treatments for liver cancer has recently been attributed to the existence of cancer stem cells, which are difficult to kill using current drugs due to their chemoresistant properties as well as their ability to stimulate neoangiogenesis. The aim of the current study was to evaluate in vitro the antitumor efficacy of arsenic trioxide in combination with conventional chemotherapy, as proposed by the concept of "differentiation therapy" in anticancer research.

MATERIALS AND METHODS

Cancer stem cells showed enhanced chemoresistance to cancer drugs (carboplatin and doxorubicin) and had the ability to exclude rhodamine 123 dye, proving the existence of the multidrug resistance efflux pump. Arsenic trioxide was added prior to a tyrosine kinase inhibitor or to a slightly modified PIAF regimen with capecitabine replacing 5-fluorouracil. We also compared both cancer and normal stem cell lines with the hepG2 non-stem liver cancer cell line to investigate the differences between differentiated and more anaplastic cells. Molecular characterization (immunocytochemistry and RT-PCR analysis) of all the cell lines was carried out.

RESULTS

Initially, the cells had a high proliferative potential, even when cultured in a medium supplemented with cytostatics, eliminated rhodamine 123 immediately in culture and also formed spheroids in suspension. The molecular characterization showed the expression of albumin, α1-antitrypsin, α-fetoprotein, citokeratin-18, telomerase, CD90 and CD133. Low concentrations of arsenic trioxide lead to morphologic differentiation and differentiation-associated cytochemical features, like increased sensitivity to cytostatic drugs.

CONCLUSION

Our study suggests that arsenic trioxide sensitizes liver stem-like cancer cells to conventional chemotherapy. Still, further studies on animal models will be needed before we implement this idea in human clinical trials.

Derivatization of haemoglobin with periodate-generated reticulation agents: evaluation of oxidative reactivity for potential blood substitutes

Periodate modification of the sugar moiety in sugars, including adenosine triphosphate (ATP), has previously been employed in order to prepare dialdehyde-type reagents, which were then utilized in crosslinking reactions on haemoglobin, yielding polymerized material with useful dioxygen-binding properties and hence proposed as possible artificial oxygen carriers ('blood substitutes'). Here, the periodate protocol is shown to be applicable to a wider range of oxygen-containing compounds, illustrated by starch and polyethylene glycol. Derivatization protocols are described for haemoglobin with such periodate-treated crosslinking agents, and the dioxygen-binding properties and redox reactivities are investigated for the derivatized haemoglobins, with emphasis on pro-oxidative properties. There is a general tendency of the derivatization to result in higher autooxidation rates. The peroxide reactivity of the met (ferric) form is also affected by derivatization, as witnessed, among others, by varying yields of ferryl [Fe (IV)-oxo] and free radical generated. In cell, culture tests (human umbilical vein epithelial cells, HUVEC), the derivatization protocols show no toxic effect.

Arsenic trioxide sensitizes cancer stem cells to chemoradiotherapy. A new approach in the treatment of inoperable glioblastoma multiforme

PURPOSE

glioblastoma multiforme (GBM) still bears a very dismal prognosis even with complete resection followed by adjuvant chemoradiation. The aim of the current study was to evaluate in vitro the antitumor efficacy of arsenic trioxide (ATO) in combination with ionizing radiation plus temozolomide and bevacizumab against cultured glioblastoma stem-like cells, as possible way to increase the therapeutic index in patients diagnosed with recurrent, therapy-refractory GBM.

METHODS

stem-like tumor cells isolated from a GBM biopsy were established by cell proliferation assays and upregulation of stem cell markers, as proven by reverse transcription - polymerase chain reaction (RT-PCR). Low concentrations of ATO were added prior to temozolomide, bevacizumab and ionizing irradiation.

RESULTS

molecular analysis showed that cells expressed CXCR4, Oct-3/4 and GAPDH when compared to placental mesenchymal stem cells, as well as nestin, GFAP and neurofilament protein. Low concentrations of ATO led to morphologic differentiation, with fewer stem cells in Go state and differentiation-associated cytochemical features, like increased sensitivity to cytostatic drugs and radiotherapy.

CONCLUSION

ATO exposure before conventional postoperative chemoradiotherapy for GBM might increase treatment efficacy. Further in vivo experiments on laboratory animals and analysis of absorption rate and side effects are required.

Enhanced chemoresistance and tumor sphere formation as a laboratory model for peritoneal micrometastasis in epithelial ovarian cancer

BACKGROUND AND PURPOSE

Ovarian cancers are composed of heterogeneous cell populations, including highly proliferative immature precursors and differentiated cells that may belong to different lineages. The main reason why epithelial ovarian cancer is difficult to treat is the unusual mechanism of dissemination that involves local invasion of pelvic and abdominal organs. But, unlike many other carcinomas, initial dissemination rarely requires blood or lymph vessels. Because it has been proven that aggregates of malignant cells within the ascites of patients diagnosed with ovarian cancer represent an impediment to cure such cancers, in the present study we adopted suspension culture combined with anti-cancer regimens as a laboratory strategy for research of the initial process of peritoneal micrometastasis.

EXPERIMENTAL DESIGN

MLS human ovarian cancer cells were cultured in serum-free medium. Cells of passage eight were treated in combination with the anticancer agent doxorubicin at different peak plasma concentrations for 24 hours, and then maintained under suspension culture. The acquired increased aggressiveness properties was confirmed by multidrug resistance assays and by their ability to grow in an anchorage-independent manner in vitro as tumor spheroids.

RESULTS

Cells selected after chemotherapy had a increased proliferative potential, eliminated Rhodamine 123 in culture and also formed spheroids in suspension.

CONCLUSIONS

Here we present direct evidence that the metastasis of human ovarian cancer may be a result of transformation and dysfunction of immature precursor cells in the ovary. Also, spheroid formation may represent a key component of chemotherapy recurrence and a better understanding of these 3D structures can contribute to the development of new treatments for metastatic carcinoma.

Comparative study of two evaluation methods for the genotoxic effects of environmental heavy metals on normal cells

Genetic modifications caused by chronic exposure to low levels of toxic metals may activate stress-signaling pathways, thus increasing cancer incidence among affected individuals. The aim of this study was to evaluate the relationship between exposure to heavy metals and the incidence of chromosomal aberrations and DNA lesions in a chronically exposed population by using specific biomarkers. The study included 156 subjects divided into two major groups: exposed individuals (in a heavy metal contaminated region, Maramures, Romania) and non-exposed population, as control group (Cluj, Romania). We compared the results of two cytogenetic methods for the detection and quantification of DNA lesions and chromosomal aberrations in normal human cells: Single Cell Gel Electrophoresis or Comet assay and Cytokinesis Block Micronucleus assay. The methods were performed on lymphocytes isolated from whole blood in density gradient. The basal DNA lesions and chromosomal aberrations were evaluated, as well as the repair capacity of the supplementary lesions induced by genotoxic agents such as ionizing radiations. Our results showed a great interindividual variability in the basal level of the DNA lesions and chromosomal aberrations, between and within the groups, the most affected being the heavy metals-exposed groups. Non-exposed subjects from rural area Cluj appeared to be more susceptible to the induction of supplementary DNA lesions and chromosomal aberrations by irradiation. The most efficient repair capacity of the radio-induced DNA lesions was observed in the non-exposed Cluj urban group. Both cytogenetic assays (as tools for detection of DNA lesions and chromosomal aberrations) may be used in human biomonitoring studies as indicators of early biological effects induced by exposure to heavy metals.

Antiproliferative effect and genotoxicity of novel synthesized palladium complexes with organoarsenic ligands

Three new palladium complexes with general formula [PdCl(2)L(2)], where L=heterofunctional organoarsenic ligand: (2-isopropoxyphenyl)diphenylarsine (1), (2-methoxyphenyl)-diphenylarsine (2) and (2-hydroxyphenyl)diphenylarsine (3) have been synthesized and fully characterized, including X-ray crystallographic data. Their potential antitumor effect and genotoxicity have been studied as well. The viability test performed on human tumor (MLS) and normal (Hfl-1) cell lines indicates significant cytotoxicity of complexes, which is higher in tumor cells than in normal cells. The lethal doses are comparable with those of standard metal-based chemotherapeutical drugs (carboplatin and oxaliplatin). These palladium complexes exhibit a higher cytotoxicity against tumor cells as against normal cells in vitro. A new static cytometric method was developed and simultaneously the classic AnnexinV test was performed. Complex 2 has an important capacity to induce apoptosis in tumor cells. The apoptotic process is triggered due to the interaction of these complexes with secondary structure of DNA in treated cells. The alkaline single-cell gel assay shows that the level of DNA damages induced by compounds 2 and 3 are significantly higher in tumor cells as in normal cells. These studies shown that complexes 1, 2 and 3 have biologic activity, the effect of complex 2 being superior to its platinum analogues, attributable to its structure.

Effects of 60Co gamma-rays on human osteoprogenitor cells

BACKGROUND

Radiation therapy is one of the most efficient treatments of neoplastic diseases used worldwide. However, patients who undergo radiotherapy may develop side effects that can be life threatening because tissue complications caused by radiation-induced stem cell depletion may result in structural and functional alterations of the surrounding matrix. This treatment also damages the osteogenic activity of human bone marrow by suppressing osteoblasts, leading to post-irradiation sequelae. Even if widely used in oncology, there is still little information on the fate and potential therapeutic efficacy of electromagnetic rays.

MATERIAL AND METHODS

We addressed this question using both human mesenchymal stem cells and osteoblasts. Monoclonal antibody characterization identified specific surface markers for stem cells (SSEA-4, CD29, CD105, Oct 3, Nanog and SOX2) and osteoblasts (Osteopontin and Osteonectin). The technique of anti-alkaline phosphatase FITC-staining demonstrated the presence of this specific ectoenzyme. Cells were cultured in complex osteogenic medium (DMEM, 15% fetal calf serum, non-essential amino acids, L-glutamine, dexametazone, ascorbic acid, insulin, TGF-beta, BMP-2 and beta-glycero-phosphate) after being irradiated at 0.5 Gy, 1 Gy, 2 Gy and 4 Gy using a Theratron 1000 60Co source. The viability of irradiated cells was assessed using Trypan Blue staining. The comparison between cell lineages after culture in osteogenic media regarding phenotypical characterization and the intensity of the mineralization process included histology stainings (Alizarin Red S, Alcian Blue and von Kossa), and the MTT-based proliferation assay.

RESULTS

After irradiation, the proliferation and differentiation of osteoprogenitor cells is dose-dependent.

CONCLUSIONS

This study is one among the first papers investigating the biophysics of low-dose gamma-irradiation on stem cell culture, focusing on the potential applications in radiation oncology and various palliative treatments.