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Mast cells are hematopoietic-lineage cells that participate in immunoglobulin E (IgE)-associated immune responses, including allergic reactions and parasite resistance. Recent studies have shown that zinc (Zn) ion can behave as an intracellular signaling molecule and that Zn is involved in mast cell activation. We demonstrated that mast cells stimulated through the high-affinity IgE receptor (FcεRI) rapidly release intracellular Zn from the endoplasmic reticulum (ER), and we named this phenomenon the "Zn wave". Furthermore, we found that the L-type calcium channel (LTCC) is the gatekeeper for the Zn wave. LTCC antagonists inhibited the Zn wave, and an agonist was sufficient to induce it. Notably, LTCC was mainly localized to the ER rather than to the plasma membrane in mast cells, and the Zn wave was impaired by LTCC knockdown. We also found that the LTCC-mediated Zn wave positively controlled inflammatory cytokine gene induction by enhancing the DNA-binding activity of nuclear factor-kappa B (NF-κB). These findings indicated that the LTCC has a novel function as a gatekeeper for the Zn wave, which is involved in regulating NF-κB signaling. In this review, we describe our current understanding of Zn signaling, especially with regard to the Zn wave and the role of Zn signaling in mast cells.

Androgen ablation therapy is performed for prostate cancer patients especially with advanced stage. Nevertheless, outgrowth of hormone independent cancer cells occurs within several years and leads to a lethal condition, so-called castration resistant prostate cancer (CRPC). Even in CRPC cells under low levels of serum androgens, androgen receptor (AR) signaling still functions and is engaged in the establishment of CRPC. Recently, novel AR antagonists have been developed such as enzalutamide or ARN-509. This review focuses on these AR antagonists that have some features including high affinity to AR compared with bicalutamide, preventing nuclear translocation and DNA binding. These new hormonal agents have changed the landscape of CRPC treatment with a promising outcome.

Dysregulated production of reactive oxygen species (ROS) during oxidative stress has been associated with a number of inflammatory and age-related degenerative diseases. ROS can directly react with DNA to form oxidized DNA bases. Direct protein oxidation and carbonylation occur on certain amino acid residues resulting in various post-translational modifications. ROS can also initiate the formation of lipid hydroperoxides, which undergo homolytic decomposition to the α,β-unsaturated aldehydic bifunctional electrophiles such as 4-oxo-2(E)-nonenal (ONE) and 4-hydroxy-2(E)-nonenal (HNE). Intracellular generation of highly reactive aldehydes can then result in the formation of DNA and protein adducts. ONE-derived heptanone-etheno and HNE-derived propano DNA adducts have been detected and shown to be mutagenic in a variety of biological systems. In addition, ONE and HNE are involved in protein dysfunctions and altered gene regulations through the modification of amino acid residues and crosslinking of proteins. Our recent study on human skin keratins has identified specific K1 methionine residues as the most susceptible sites to oxidation with hydrogen peroxide, which can be potential biomarkers of oxidative skin damage. The reactions of angiotensin (Ang) II with ONE or HNE produced several modified Ang IIs including a novel pyruvamide-Ang II that formed via oxidative decarboxylation of N-terminal aspartic acid. Subsequently, it has been revealed that the oxidative modifications on the N-terminus of Ang II disrupt interactions with Ang II type 1 receptor and aminopeptidase A, which could affect the regulation of cardiovascular function.

An artificial transcription factor that can regulate the expression of specific genes at a desired time is very useful for research in chemical biology, cell biology, and future gene therapy. A C2H2 zinc finger motif, one of zinc-containing proteins, is known as the most ubiquitous DNA binding motif. The motif is attractive for designing artificial transcription factors with desired DNA binding specificities because of its characteristic DNA binding properties: (1) recognition of 3 bp per motif, (2) tandemly connected modular structure, and (3) binding to non-palindrome sequences as a monomer. Taking advantage of these properties, artificial DNA binding proteins with new DNA binding characteristics have been designed. By changing the linker region between two 3-zinc finger domains, artificial 6-zinc finger proteins were developed and shown to skip DNA sequences. Zinc-responsive transcription factors were created by altering one of the zinc ligands. An artificial zinc finger transcription factor targeting a core clock gene induced phase shifts of the cellular "circadian rhythm". Herein, I will summarize creation and function of the above-mentioned artificial zinc finger-type DNA binding proteins and transcription factors.

In the 21st century the category of biomedicine is now expanding from low-molecular drugs to recombinant proteins, antibodies, and nucleic acids (e.q., siRNA and plasmid DNA). In this era also, development of a novel nanotechnology to control intracellular trafficking is highly desired. For a promising gene therapy, an efficient nuclear delivery vector is a minimum requirement. Quantitative and mechanism-based information on differences in transfection efficiency between viral and non-viral vectors would be highly useful to improve the effectiveness of non-viral vectors. In this review, we will summarize our recent progress in quantitative comparison and underlying mechanisms of the intracellular trafficking between adenovirus vectors and plasmid DNA (pDNA) transfected by non-viral vectors. Our analysis has revealed that poor post-nuclear delivery events, as well as the nuclear delivery process itself are key processes to focus on. Especially, less effective transcription and translation are most likely due to poor nuclear decondensation and excess electrostatic interaction between mRNA and the gene carrier, respectively. Meanwhile, we have developed a multi-functional envelope-type nano device (MEND), in which the pDNA/polycation core is encapsulated in the lipid bilayers. Based on feedback information concerning the rate-limiting processes of gene carriers, we controlled the number of lipid envelopes to enhance the decoating of encapsulated pDNA from the envelope structure. As an expanded application of this concept, we have developed a tetra-lamellar MEND (T-MEND), which is designed to overcome the endosome and nuclear membranes by step-wise membrane fusion.

Thalidomide, N-phtalidoglutamide, is a well-known teratogenic agent when given to pregnant women. It was first synthesized by CIBA in 1953, but put on market in Germany as a sedative, but Dr. Rentz reported first the relation with the teratogenicity. However, its clinical activity to erythema nodosum leprosum was accidentally found. In 1997, thalidomide was found active to multiple myeloma, but its clinical use is not authorized yet in Japan. The mechanisms which so far reported are as follows. 1) The inhibitory activity of angiogenesis 2) NF-kappaB suppression 3) Suppression of GVHD, and other activity to immunity (suppression or augmentation), suppression of TNFa 4) Suppression of intracellular adhesion molecule 5) Binding to DNA From these reports, the teratogenicity or the clinical activities have been somewhat understood. Recently clinical studies of the analogue, Lenalidomide, have been reported.

Transcriptional activation of metallothionein (MT) genes by heavy metals is a valuable system for understanding the functions of MT as well as the cellular response against heavy metals. Although it is now known that heavy metal signals culminating in MT induction converge upon a transcription factor MTF-1, the mechanism underlying the MTF-1 response to heavy metals has not been elucidated. To address this issue, we investigated various aspects of the in vivo response of MTF-1 against heavy metals. Chromatin immunoprecipitation assay showed that heavy metal-dependent DNA binding of MTF-1 is the critical step in vivo. MTF-1 is primarily localized in the nucleus so that heavy metal-dependent nuclear translocation demonstrated by other groups does not seem to be universal and hence may not be critical for activation of MTF-1. In the six Zn finger motifs, the hallmark of MTF-1, the third and the fourth fingers are essential for the nuclear localization of MTF-1. Furthermore, all fingers except the last are important for transcriptional activation function of MTF-1, suggesting their key role for MTF-1 function. Also, a cysteine cluster structure located in the C-terminal region of MTF-1 is critical for transactivating function of MTF-1. These results suggest a central role of the Zn-finger domain and intramolecular cooperation through a structural change of MTF-1 for its response to heavy metal challenge.

Differently from target-based anticancer drugs, molecular mechanisms of actions are not well-known in many of the classical antineoplastic agents. With the exception of vinca alkaloids and taxanes, all of the classical antineoplastic agents work on DNA metabolism in cells and can therefore be categorised as 'DNA metabolism inhibitor'. Cellular sensitivity against these drugs largely depends on various activities in DNA metabolism, particularly in DNA repair. However, DNA repair as a determinant of drug sensitivity had long received little attention. DNA mismatch repair (MMR) is now regarded as an important determinant to alter cellular sensitivities against various drugs including fluoropyrimidines, platinum compounds and topoisomerase inhibitors. However, molecular mechanisms of this connection are still unknown. In particular, the relationship between MMR and 5-fluorouraci (l 5-FU) sensitivity is now being approached by examining the tumour MMR status and clinical outcomes in colorectal cancer patients treated with 5-FU-based adjuvant chemotherapies. However, reported results lack consistency, possibly due to the methodological problems in assays used to determine the MMR status. On the other hand, nucleotide excision repair (NER) is also regarded as an important determinant of cisplatin (CDDP) sensitivity. Expression of ERCC 1, a component of this complex multi-protein system, has been reported to be a determinant of prognosis in CDDP-treated non-small-cell lung cancer patients. In order to establish the significance of DNA repair as a determinant of tumour chemosensitivity, further basic studies, particularly ones approached from biochemical viewpoints, are required. Clinical studies supported by accurate assay techniques are also needed.

Runt-related transcription factor 2 (Runx2) is an essential transcription factor for osteoblast differentiation, and the expression is regulated by many factors including bone morphogenetic protein (BMP). Core binding factorbeta (Cbf beta) is required for DNA binding of Runx2 and Runx2-dependent transcription, and Cbf beta regulates Runx2 function isoform-dependently. Further, ability of Runx2 for transcriptional activation is regulated by many molecules. Phosphoinositide 3-kinase (PI3K)-Akt signaling enhances DNA binding of Runx2 and Runx2-dependent transcription, and Runx2 upregulates PI3K subunits (p85 and p110 beta) and Akt. Therefore, Runx2 and PI3K-Akt signaling are mutually dependent each other in the regulation of osteoblast and chondrocyte differentiation and their migration.