ERE-dependent transcription and cell proliferation: Independency of these two processes mediated by the introduction of a sulfone function into the weak estrogen estrothiazine

Roles of estrogen and its receptors in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by abnormal steroid hormone levels in peripheral blood and poor-quality oocytes. In the ovary, androgen is produced by theca cells, and estrogen is produced by granulosa cells. Androgen is converted to estrogen in granulosa cells, with cytochrome P450 aromatase as the limiting enzyme during this process. Estrogen receptors (ER) include ER alpha, ER beta, and membrane receptor GPR30. Studies have demonstrated that the abnormal functions of estrogen and its receptors and estradiol synthesis-related enzymes are closely related to PCOS. In recent years, some estrogen-related drugs have made significant progress in clinical application for subfertility with PCOS, such as letrozole and clomiphene. This article will elaborate on the recent advances in PCOS caused by abnormal expression of estrogen and its receptors and the application of related targeted small molecule drugs in clinical research and treatment.

Involvement of multiple cytochrome P450 isoenzymes in drug interactions between ritonavir and direct oral anticoagulants

Herein, we aimed to determine the significance of drug interactions (DIs) between ritonavir and direct oral anticoagulants (DOACs) and identify the involved cytochrome P450 (CYP) isoenzymes. Using an in vitro cocktail method with human liver microsomes (HLM), we observed that ritonavir strongly inhibited CYPs in the following order: CYP3A, CYP2C8, CYP2D6, CYP2C9, CYP2C19, CYP2B6, and CYP2J2 (IC50: 0.023-6.79 μM). The degree of CYP2J2 inhibition was inconclusive, given the substantial discrepancy between the HLM and human expression system. Selective inhibition of CYP3A decreased the O-demethylation of apixaban by only 13.4%, and the involvement of multiple CYP isoenzymes was suggested, all of which were inhibited by ritonavir. Multiple CYP isoenzymes contributed also to the metabolism of rivaroxaban. Replacement of the incubation medium with phosphate buffer instead of HEPES enhanced apixaban hydroxylation. On surveying the FDA Adverse Event Reporting System, we detected that the signal of the proportional reporting ratio of "death" and found increase for "hemoglobin decreased" (12.5-fold) and "procedural hemorrhage" (201.9-fold) on administering apixaban with ritonavir; these were far less significant for other CYP3A inhibitors. Overall, these findings suggest that co-administration of ritonavir-boosted drugs with DOACs may induce serious DIs owing to the simultaneous inhibition of multiple CYP isoenzymes.

In situ mapping of biomineral skeletal proteins by molecular recognition imaging with antibody-functionalized AFM tips

Spatial localizing of skeletal proteins in biogenic minerals remains a challenge in biomineralization research. To address this goal, we developed a novel in situ mapping technique based on molecular recognition measurements via atomic force microscopy (AFM), which requires three steps: (1) the development and purification of a polyclonal antibody elicited against the target protein, (2) its covalent coupling to a silicon nitride AFM tip ('functionalization'), and (3) scanning of an appropriately prepared biomineral surface. We applied this approach to a soluble shell protein - accripin11 - recently identified as a major component of the calcitic prisms of the fan mussel Pinna nobilis [1]. Multiple tests reveal that accripin11 is evenly distributed at the surface of the prisms and also present in the organic sheaths surrounding the calcitic prisms, indicating that this protein is both intra- and inter-crystalline. We observed that the adhesion force in transverse sections is about twice higher than in longitudinal sections, suggesting that accripin11 may exhibit preferred orientation in the biomineral. To our knowledge, this is the first time that a protein is localized by molecular recognition atomic force microscopy with antibody-functionalized tips in a biogenic mineral. The 'pros' and 'cons' of this methodology are discussed in comparison with more 'classical' approaches like immunogold. This technique, which leaves the surface to analyze clean, might prove useful for clinical tests on non-pathological (bone, teeth) or pathological (kidney stone) biomineralizations. Studies using implants with protein-doped calcium phosphate coating can also benefit from this technology. STATEMENT OF SIGNIFICANCE: Our paper deals with an unconventional technical approach for localizing proteins that are occluded in biominerals. This technique relies on the use of molecular recognition atomic force microscopy with antibody-functionalized tips. Although such approach has been employed in other system, this is the very first time that it is developed for biominerals. In comparison to more classical approaches (such as immunogold), AFM microscopy with antibody-functionalized tips allows higher magnification and keeps the scanned surface clean for other biophysical characterizations. Our method has a general scope as it can be applied in human health, for non-pathological (bone, teeth) and pathological (kidney stone) biomineralizations as well as for bone implants coated with protein-doped calcium phosphate.

Pathological Maintenance and Evolution of Breast Cancer: The Convergence of Irreversible Biological Actions of ER Alpha

Estrogen receptor alpha (ERα) is a modulator of breast cancer maintenance and evolution. Hence, analysis of underlying mechanisms by which ERα operates is of importance for the improvement of the hormonal therapy of the disease. This review focuses on the irreversible character of the mechanism of action of ERα, which also concerns other members of the steroid hormones receptors family. ERα moves in permanence between targets localized especially at the chromatin level to accomplish gene transcriptions imposed by the estrogenic ligands and specific antagonists. Receptor association as at the plasma membrane, where it interacts with other recruitment sites, extends its regulatory potency to growth factors and related peptides through activation of signal transductions pathways. If the latter procedure is suitable for the transcriptions in which the receptor operates as a coregulator of another transcription factor, it is of marginal influence with regard to the direct estrogenic regulation procedure, especially in the context of the present review. Irreversibility of the successive steps of the underlying transcription cycle guarantees maintenance of homeostasis and evolution according to vital necessities. To justify this statement, reported data are essentially described in a holistic view rather than in the context of exhaustive analysis of a molecular event contributing to a specific function as well as in a complementary perspective to elaborate new therapeutic approaches with antagonistic potencies against those tumors promoting ERα properties.

Exploring Protein⁻Protein Interaction in the Study of Hormone-Dependent Cancers

Estrogen receptors promote target gene transcription when they form a dimer, in which two identical (homodimer) or different (heterodimer) proteins are bound to each other. In hormone-dependent cancers, hormone receptor dimerization plays pivotal roles, not only in the pathogenesis or development of the tumors, but also in the development of therapeutic resistance. Protein–protein interactions (PPIs), including dimerization and complex formation, have been also well-known to be required for proteins to exert their functions. The methods which could detect PPIs are genetic engineering (i.e., resonance energy transfer) and/or antibody technology (i.e., co-immunoprecipitation) using cultured cells. In addition, visualization of the target proteins in tissues can be performed using antigen–antibody reactions, as in immunohistochemistry. Furthermore, development of microscopic techniques (i.e., electron microscopy and confocal laser microscopy) has made it possible to visualize intracellular and/or intranuclear organelles. We have recently reported the visualization of estrogen receptor dimers in breast cancer tissues by using the in situ proximity ligation assay (PLA). PLA was developed along the lines of antibody technology development, and this assay has made it possible to visualize PPIs in archival tissue specimens. Localization of PPI in organelles has also become possible using super-resolution microscopes exceeding the resolution limit of conventional microscopes. Therefore, in this review, we summarize the methodologies used for studying PPIs in both cells and tissues, and review the recently reported studies on PPIs of hormones.

Dacarbazine nanoparticle topical delivery system for the treatment of melanoma

Dacarbazine (DZ) is poorly soluble in water with the short half-life in blood circulation, low rate of response with the toxic effect which ultimately limits its utilization of the treatment of skin cancer. In view of this background current study was designed for development of dacarbazine laden nanoparticle (DZNP) and dacarbazine laden nanocream (DZNC) topical delivery system for the treatment of melanoma. Firstly DZNP was prepared. By using DZNP its cream formulation prepared for topic drug delivery for melanoma. Dacarbazine nanoparticle and its cream were evaluated for morphology, drug load capacity, efficiency of nanoencapsulation and size of particle and zeta potential, Transmission Electron Microscopy (TEM), determination of pH, spreadability and viscosity, in vitro drug release capacity and its cytotoxic potential. The particle size of DZNP and DZNC was 16.3 ± 8.1 nm and 16.9 ± 7.8 nm respectively. pH value and spreadability of nanoparticle cream were found to be 6.7 ± 0.14 g cm/sec and 55.23 ± 3.13 g cm/sec respectively. Nanoencapsulation efficiency and Drug loading capacity were 67.4 ± 3.5% and 6.73 mg/10 mg respectively. IC50 of dacarbazine nanoparticle was 0.19 mg/ml while it was 0.63 mg/ml for nanoparticle cream. It can be concluded that DZNP and its cream can be effectively used as a topical formulation for the treatment of melanoma.