B-Group Vitamins: Chemoprevention?

The importance of vitamins in the prevention of cancer has attracted the attention of consumers, nutritionists and scientists for decades. The mechanisms of carcinogenesis, extended in the context of the function of vitamins, i.e.

Cytotoxicity Evaluation and Crystallochemical Analysis of a Novel and Commercially Available Bone Substitute Material.

Background: Alloplastic biomaterials are an alternative for autologous transplants and xenografts in oral surgery and dental implantology. These non-immunogenic and resorbable materials are becoming the basis for complete and predictable guided bone regeneration in many cases. The chemical composition of a great majority of them is based on calcium phosphate salts.

[The role of thiamine in neurodegenerative diseases].

Vitamin B1 (thiamine) plays an important role in metabolism. It is indispensable for normal growth and development of the organism. Thiamine has a favourable impact on a number of systems, including the digestive, cardiovascular and nervous systems.

[The phenomenon of vitamin D].

The receptor of vitamin D (VDR) is present in most non-skeletal human cells, suggesting its role beyond the bone and calcium metabolism. The relationship between vitamin D and the respiratory tract is a consequence of its activity in the immune system. Some gastrointestinal diseases, such as inflammatory bowel disease, coeliac disease, liver, pancreas or cardiac diseases, lead to vitamin D deficiency.

Formation and preclinical evaluation of a new alloplastic injectable bone substitute material.

Alloplastic bone substitute materials are raising some more interest as an alternative for autologic transplants and xenogenic materials especially in oral surgery over the last few years. These non-immunogenic and completely resorbable biomaterials are the basis for complete and predictable guided bone regeneration. In the majority of cases, such a material is chosen because of its convenient application by surgeons.

Modulation of apoptosis protein profiles--role of P-gp in HeLa cells exposed to doxorubicin.

As shown previously doxorubicin (1 μM) plus sulindac (50 μM) reduced the expression of ABCB1 (ATP-binding cassette, sub-family B (MDR/TAP), member 1) mRNA in HeLa cells and this effect was accompanied by increased apoptosis. The aim of this study was to define if the decrease of ABCB1 expression or blocking of P-glycoprotein (P-gp) can affect the expression of the apoptotic genes determined with use of quantitative real time polymerase chain reaction (qRT-PCR). Western blot was used for visualization of chosen pro- and antiapoptotic proteins.

[Epigenetics and etiology of neurodegenerative diseases].

Determination of specific gene profile expression is essential for morphological and functional differentiation of cells in the human organism. The human genome consists of 25-30 thousands genes but only some of them are expressed in each cell. Epigenetic modifications such as DNA methylation, histone and chromatin modifications or non-coding RNA functions are also responsible for the unique gene expression patterns.

Possible role of HSP60 in synergistic action of anthracyclines and sulindac in HeLa cells.

As was observed in the earlier studies, doxorubicin (DOX) induced apoptosis in HeLa cells and that effect was potentiated significantly by sulindac (SUL). The aim of the current work was to study the effects of DOX and SUL on HSP60, HSF1 and HSP60 expression and the influence of DOX and SUL on HSP60 translocation. Expression of HSP60 and HSF1 was determined with QRT-PCR; the expression and localization of HSP60 were evaluated with Western blot.

[The role of the proteasome for therapy of incurable diseases].

Proteins constitute the basic building elements of living organisms. Proteins have a limited lifetime in a cell. The so called "half-life period" of proteins is diverse and lasts from several minutes to several days.

Synergistic action of doxorubicin and sulindac in human cervix carcinoma cells - studies on possible mechanisms.

Background: Epidemiologic and experimental studies have shown that cyclooxygenase-2 (COX-2) inhibitors as non-steroidal anti-inflammatory drugs (NSAIDs) are effective chemopreventive agents. The mechanisms underlying the antitumor activity of COX-2 inhibitors are thought to involve inhibition of COX-2 enzyme activity and induction of apoptosis. The aim of the current work was to study the mechanisms of synergistic action noted in HeLa cervical carcinoma cells under doxorubicin (DOX) and sulindac (SUL) co-treatment.

NFkappaB activation and drug sensitivity in human neoplastic cells treated with anthracyclines.

NFkappaB (nuclear factor kappaB) is a transcription factor controlling, among others, cell proliferation and apoptosis. The potent activators of NFkappaB are anthracyclines which can activate apoptotic processes. As shown by some authors, NFkappaB activated by these drugs well correlated with their cytotoxic activity.

Effect of structural modification at the 4, 3', and 2' positions of doxorubicin on topoisomerase II poisoning, apoptosis, and cytotoxicity in human melanoma cells.

Introduction: The mechanism of the cytotoxicity of anthracyclines is pleiotropic and its significance in cell growth inhibition seems to be highly specific and dependent on cell type and anthracycline drug. Resistance and the high cardiotoxicity of anthracyclines have stimulated many studies aimed at identifying critical substituents required for optimal activity. Many authors point to the fact that the double-strand breaks, the consequence of the activity of topoisomerase II poisons, and the inability of cells to repair the DNA lesions are the signal for apoptosis.

Topoisomerase II alpha expression and cytotoxicity of anthracyclines in human neoplastic cells.

Topoisomerase II is ATP dependent enzyme that catalyzes DNA strand passage, the pivotal process in replication, transcription, recombination etc. As part of this breakage and religation process the intermediate generated is a cleavable complex between DNA and topoisomerase II. This complex is the target for topoisomerase II inhibitors like epipodophyllotoxins, actinomycin D or anthracyclines.

Relationship between topoisomerase II-DNA cleavable complexes, apoptosis and cytotoxic activity of anthracyclines in human cervix carcinoma cells.

The use of anthracyclines as antitumor drugs dates back to the 1970s, but the mechanism of the cytotoxicity of these compounds has long been a matter of debate. There is increasing evidence indicating that drug-induced cytotoxicity commonly converges on the induction of apoptosis. Many authors point to the fact that double-strand breaks, resulting from stabilization of cleavable complexes, are the signal for the initiation of the apoptotic cascade.

Constitutive activation of transcription factor NFkappaB as a possible marker of sensitivity of neoplastic cells to anthracyclines.

NFkappaB, a member of the Rel family of transcription factors has been found to be critically important for control of cell proliferation and apoptosis. Although rare, there are systems in which NFkappaB has occurred as pro-apoptotic factor. The potent activators of NFkappaB are anthracycline anticancer drugs which induce the events of apoptosis.

The effect of new anthracycline derivatives on the induction of apoptotic processes in human neoplastic cells.

This study was an attempt to determine the effect of a selected anthracycline derivative, WP903, on apoptotic processes in human melanoma cells depending on intracellular concentrations of the compound, and to evaluate the significance of apoptosis induction for the cytotoxic effect of anthracycline antibiotics. It was found that the WP903, contrary to ADR (adriamycin) is a strong inducer of apoptotic processes in ME18 human melanoma cells regardless of their susceptibility to adriamycin and WP903. The cells were treated for 24 h with ADR (1 and 5 microg/ml) or WP903 (0.

Studies on the influence of vitamin D3 metabolites on apoptosis induction in human neoplastic cells.

The vitamin D is involved in essential cell regulatory processes such as proliferation and differentiation in a number of different cell types including cancer cells. Adriamycin is one of the most effective agents in the treatment of many types of solid tumours and leukemias. The common features in the biological activity, expressed by vitamin D family members and adriamycin such as: apoptosis induction, influence on antioxidant enzymes activity etc.