stilbenes and Fanconi-Anemia

Fanconi Anemia (FA) is a rare and complex inherited blood disorder associated with bone marrow failure and malignancies. Many alterations in FA physiology appear linked to red-ox unbalance including alterations in the morphology and structure of nuclei, intermediate filaments and mitochondria, defective respiration, reduced ATP production and altered ATP/AMP ratio. These defects are consistently associated with impaired oxygen metabolism indeed treatment with antioxidants N-acetylcysteine (NAC) and resveratrol (RV) does rescue FA physiology. Due to the importance of the intracellular calcium signaling and its key function in the control of intracellular functions we were interested to study calcium homeostasis in FA. We found that FANCA cells display a dramatically low intracellular calcium concentration ([Ca(2+)]i) in resting conditions. This condition affects cellular responses to stress. The flux of Ca(2+) mobilized by H2O2 from internal stores is significantly lower in FANCA cells in comparison to controls. The low basal [Ca(2+)]i in FANCA appears to be an actively maintained process controlled by a finely tuned interplay between different intracellular Ca(2+) stores. The defects associated with the altered Ca(2+) homeostasis appear consistently overlapping those related to the unbalanced oxidative metabolism in FA cells underlining a contiguity between oxidative stress and calcium homeostasis.

Topics: Acetylcysteine; Antioxidants; Calcium; Calcium-Transporting ATPases; Carbocyanines; Cell Line; Fanconi Anemia; Fanconi Anemia Complementation Group Proteins; Fibroblasts; Heterocyclic Compounds, 3-Ring; Homeostasis; Humans; Hydrogen Peroxide; Kinetics; Microscopy, Confocal; Mitochondria; Models, Biological; Resveratrol; Stilbenes; Thapsigargin

Head and neck squamous cell carcinoma (HNSCC) and acute myeloid leukemia are the major causes of mortality and morbidity in Fanconi anemia (FA) patients. The objective of this study was to investigate the antineoplastic activity of PB, an antineoplastic nutrient mixture (containing quercetin, curcumin, green tea, cruciferex and resveratrol) on human FA HNSCC in vitro and in vivo. Human FA HNSCC cell line OHSU-974 (Fanconi Anemia Research Fund) was cultured in RPMI medium supplemented with 20% FBS and anti-biotics. At near confluence, cells were treated in triplicate with different concentrations of PB: 0, 10, 25, 50, 75 and 100 µg/ml. Cells were also treated with PMA to induce MMP-9 activity. Cell proliferation was detected by MTT assay, secretion of MMPs by gelatinase zymography, invasion through Matrigel, migration by scratch test and morphology by hematoxylin and eosin (H&E) staining. In vivo, athymic male nude mice (n=12) were inoculated with 3x106 OHSU-974 cells subcutaneously and randomly divided into two groups: group A was fed a regular diet and group B a regular diet supplemented with 1% PB. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. NM inhibited the growth of OHSU-974 tumor by 67.6% (p<0.0001) and tumor burden by 63.6% (p<0.0001). PB demonstrated dose-dependent inhibition of cell proliferation, with 27% (p=0.0003) and 48% (p=0.0004) toxicity at 75 and 100 µg/ml, respectively. Zymography revealed MMP-2 and PMA-induced MMP-9 secretion. PB suppressed secretion of both MMPs in a dose-dependent manner, with total block of both at 50 µg/ml. PB inhibited cell migration (by scratch test) and OHSU-974 invasion through Matrigel in a dose-dependent fashion with total block at 50 µg/ml. H&E staining showed no morphological changes below 50 µg/ml. The results suggest that PB has potential therapeutic use in the treatment of human FA HNSCC.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cell Survival; Curcumin; Dietary Supplements; Disease Models, Animal; Fanconi Anemia; Head and Neck Neoplasms; Humans; Male; Mice; Mice, Nude; Phytochemicals; Phytotherapy; Quercetin; Resveratrol; Squamous Cell Carcinoma of Head and Neck; Stilbenes; Tea; Xenograft Model Antitumor Assays

Fanconi anemia (FA) patients suffer from progressive bone marrow failure and often develop cancers. Previous studies showed that antioxidants tempol and resveratrol (RV) delayed tumor onset and reduced hematologic defects in FA murine models, respectively. Here we tested whether antioxidants N-acetylcysteine (NAC) or RV could delay cancer in tumor prone Fancd2(-/-) /Trp53(+/-) mice. Unlike tempol, neither compound had any significant chemopreventive effect in this model. We conclude that not all anti-oxidants are chemopreventive in FA. In addition, when given to Fancd2(-/-) mice, NAC helped maintain Fancd2(-/-) KSL cells in quiescence while tempol did not. The mechanisms behind the different actions of these antioxidants await further investigation.

Topics: Acetylcysteine; Animals; Antioxidants; Fanconi Anemia; Fanconi Anemia Complementation Group D2 Protein; Flow Cytometry; Free Radical Scavengers; Mice; Mice, Knockout; Resveratrol; Stilbenes; Tumor Suppressor Protein p53

Fanconi anemia (FA) is a genetic disorder characterised by chromosome instability, cytokine ipersensibility, bone marrow failure and abnormal haematopoiesis associated with acute myelogenous leukemia. Recent reports are contributing to characterize the peculiar FA metabolism. Central to these considerations appears that cells from complementation group A (FANCA) display an altered red-ox metabolism. Consequently the possibility to improve FA phenotypical conditions with antioxidants is considered. We have characterized from the structural and biochemical point of view the response of FANCA lymphocytes to N-acetyl-cysteine (NAC) and resveratrol (RV). Surprisingly both NAC and RV failed to revert all the characteristic of FA phenotype and moreover their effects are not super imposable. Our data suggest that we must be aware of the biological effects coming from antioxidant treatment.

Topics: Acetylcysteine; Antioxidants; Cells, Cultured; Drug Evaluation, Preclinical; Fanconi Anemia; Humans; Mitochondria; Reactive Oxygen Species; Resveratrol; Stilbenes

Progressive bone marrow failure is a major cause of morbidity and mortality in human Fanconi Anemia patients. In an effort to develop a Fanconi Anemia murine model to study bone marrow failure, we found that Fancd2(-/-) mice have readily measurable hematopoietic defects. Fancd2 deficiency was associated with a significant decline in the size of the c-Kit(+)Sca-1(+)Lineage(-) (KSL) pool and reduced stem cell repopulation and spleen colony-forming capacity. Fancd2(-/-) KSL cells showed an abnormal cell cycle status and loss of quiescence. In addition, the supportive function of the marrow microenvironment was compromised in Fancd2(-/-) mice. Treatment with Sirt1-mimetic and the antioxidant drug, resveratrol, maintained Fancd2(-/-) KSL cells in quiescence, improved the marrow microenvironment, partially corrected the abnormal cell cycle status, and significantly improved the spleen colony-forming capacity of Fancd2(-/-) bone marrow cells. We conclude that Fancd2(-/-) mice have readily quantifiable hematopoietic defects, and that this model is well suited for pharmacologic screening studies.

Topics: Animals; Antioxidants; Bone Marrow; Cell Cycle; Cell Lineage; Colony-Forming Units Assay; Fanconi Anemia; Fanconi Anemia Complementation Group D2 Protein; Hematopoietic Stem Cells; Hematopoietic System; Mice; Mice, Knockout; Mice, Transgenic; Resveratrol; Spleen; Stilbenes; Treatment Outcome