• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.427-436
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• 2012

Targeted therapy has been a very promising strategy of drug development research. Many molecular mechanims of diseases have been known to be regulated by abundance of proteins, such as receptors and hormones. Chemoprevention for treatment and prevention of diseases are continuously developed. Pre-clinical and clinical studies in chemoprevention field yielded many valuable data in preventing the onset of disease and suppressing the progress of their growth, making chemoprevention a challenging and a very rational strategy in future researches. Natural products being rich of flavonoids are those fruits belong to the genus citrus. Ethanolic extract of Citrus reticulata and Citrus aurantiifolia peels showed anticarcinogenic, antiproliferative, co-chemotherapeutic and estrogenic effects. Several examples of citrus flavonoids that are potential as chemotherapeutic agents are tangeretin, nobiletin, hesperetin, hesperidin, naringenin, and naringin. Those flavonoids have been shown to possess inhibition activity on certain cancer cells' growth through various mechanisms. Moreover, citrus flavonoids also perform promising effect in combination with several chemotherapeutic agents against the growth of cancer cells. Some mechanisms involved in those activities are through cell cycle modulation, antiangiogenic effect, and apoptosis induction.Previous studies showed that tangeretin suppressed the growth of T47D breast cancer cells by inhibiting ERK phosphorylation. While in combination with tamoxifen, doxorubicin, and 5-FU, respectively, it was proven to be synergist on several cancer cells. Hesperidin and naringenin increased cytotoxicitity of doxorubicin on MCF-7 cells and HeLa cells. Besides, citrus flavonoids also performed estrogenic effect in vivo. One example is hesperidin having the ability to decrease the concentration of serum and hepatic lipid and reduce osteoporosis of ovariectomized rats. Those studies showed the great potential of citrus fruits as natural product to be developed as not only the source of co-chemotherapeutic agents, but also phyto-estrogens. Therefore, further study needs to be conducted to explore the potential of citrus fruits in overcoming cancer.

• BMB Reports
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• v.44 no.4
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• pp.273-278
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• 2011

Destruction of the skin barrier by thermal injury induces microbial invasion, which can lead to the development of systemic infection and septic shock. Microbial pathogens possess pathogen-associated molecular patterns (PAMPs), which are recognized by conserved receptors. To understand the role of PAMPs in thermal injury-induced mice, LPS or CpG-DNA were topically applied to dorsal skin after thermal injury. We observed an increase in the number of inflammatory cell infiltrates as well as thickening in the dermis upon treatment with LPS or CpG-DNA. We also found that expression of IL-$1{\beta}$, MIP-2, and RANTES induced by thermal injury was enhanced by LPS or CpG-DNA. In addition, the proportions of $CD4^+$ and $CD^8+$ T cells in the spleen and lymph nodes were altered by LPS or CpG-DNA. These results provide important information concerning PAMPs-induced inflammation upon thermal injury and provide a basis for studying the role of PAMPs in thermal injury-induced complications.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.2023-2028
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• 2013

A number of studies have indicated that Nurr1, which belongs to a novel class of orphan nuclear receptors (the NR4A family), is important for carcinogenesis. Here we investigated expression of Nurr1 protein in benign and malignant human prostate tissues and association with clinicopathologic features using immunohistochemical techniques. Moreover, we also investigated the ability of Nurr1 to influence proliferation, migration, invasion and apoptosis of human prostate cancer cells using small interfering RNA silencing. Immunohistochemical analysis revealed that the expression of Nurr1 protein was higher in prostate cancer tissues than in benign prostate tissue (P<0.001), levels being positively correlated with tumor T classification (P = 0.003), N classification (P = 0.017), M classification (P = 0.011) and the Gleason score (P = 0.020) of prostate cancer patients. In vitro, silencing of endogenous Nurr1 attenuated cell proliferation, migration and invasion, and induced apoptosis of prostate cancer cells. These results suggest that Nurr1 may be used as an indicator for prostate cancer progression and be useful for novel potential therapeutic strategies.

• Molecules and Cells
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• v.41 no.9
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• pp.842-852
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• 2018

Notch signaling is an evolutionarily conserved pathway and involves in the regulation of various cellular and developmental processes. Ligand binding releases the intracellular domain of Notch receptor (NICD), which interacts with DNA-bound CSL [CBF1/Su(H)/Lag-1] to activate transcription of target genes. In the absence of NICD binding, CSL down-regulates target gene expression through the recruitment of various corepressor proteins including SMRT/NCoR (silencing mediator of retinoid and thyroid receptors/nuclear receptor corepressor), SHARP (SMRT/HDAC1-associated repressor protein), and KyoT2. Structural and functional studies revealed the molecular basis of these interactions, in which NICD coactivator and corepressor proteins competitively bind to ${\beta}-trefoil$ domain (BTD) of CSL using a conserved ${\varphi}W{\varphi}P$ motif (${\varphi}$ denotes any hydrophobic residues). To date, there are conflicting ideas regarding the molecular mechanism of SMRT-mediated repression of CSL as to whether CSL-SMRT interaction is direct or indirect (via the bridge factor SHARP). To solve this issue, we mapped the CSL-binding region of SMRT and employed a 'one- plus two-hybrid system' to obtain CSL interaction-defective mutants for this region. We identified the CSL-interaction module of SMRT (CIMS; amino acid 1816-1846) as the molecular determinant of its direct interaction with CSL. Notably, CIMS contains a canonical ${\varphi}W{\varphi}P$ sequence (APIWRP, amino acids 1832-1837) and directly interacts with CSL-BTD in a mode similar to other BTD-binding corepressors. Finally, we showed that CSL-interaction motif, rather than SHARP-interaction motif, of SMRT is involved in transcriptional repression of NICD in a cell-based assay. These results strongly suggest that SMRT participates in CSL-mediated repression via direct binding to CSL.

• Biomedical Science Letters
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• v.15 no.1
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• pp.93-96
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• 2009

House dust mites (HDMs) play an important role in the occurrence of allergic diseases such as asthma and atopic dermatitis. Dermatophagoides pteronyssinus (Der p) is one of the most prevalent HDMs. It mediates the activation of T cells and monocytes, and induces the elevation of immunoglobulin E levels in allergic diseases. However, the effects of Der p on human monocytes have not been fully understood. In the present study, we investigated whether or not Der p has a great effect on the chemotactic activity of the human monocytic cell line, THP-1 cells, as induced by CC chemokines. We also show that the Der p extract (DpE) increased the chemotactic activity of THP-1 cells in response to MCP-1, RANTES, MIP-1${\alpha}$, and TARC, but had no effect on the expressions of CC chemokine receptors (CCRs) binding to CC chemokines in THP-1 cells. Protease inhibitors, such as aprotinin and E64, blocked the increased chemotaxis, while cytoplasmic $Ca^{2+}$ influx mediated by these chemokines was inhibited by DpE. These results indicate that DpE increases the chemotactic activity of THP-1 cells in response to CC chemokines by regulating the cells' protease-dependent mechanism. This finding may be useful in identifying the pathogenesis of allergic diseases induced by Der p.

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.276-280
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• 2000

In order to identify the domains of the G$_{\alpha}$16 subunit G protein that are responsible for its activation by the Interleukin-8 receptor, a serious of chimeras between G$_{\alpha}$16 and G$_{\alpha}$11 were assessed for their abilities to be activated by these receptors. Co-expression of IL-8 receptor and chimeras in which the carboxyl-terminal regions of G$_{\alpha}$11 were replaced from 30 up to 156 amino acid residues with the corresponding regions of G$_{\alpha}$16 demonstrated that C-terminal 156 amino acid residues of the G$_{\alpha}$16 were not sufficient to confer IL-8 receptor interaction specificity. Testing of a reciprocal serious of chimeras composed of G$_{\alpha}$16 sequences at the amino terminus and G$_{\alpha}$11 sequences at the carboxyl terminals revealed that sequences extending from the amino tar- minus to amino acid 209 of G$_{\alpha}$16 were sufficient to 7ndow the chimera with 75-80% of interaction specificity for 7-8-induced activation. These results suggest th,.7t combined interactions of the C-terminal 30 amino acid residues and certain domains extending from the arts.ino terminus to amino acid 209 of Gal 6 protein may be involved in its couplings to IL-8 receptor.tain domains extending from the arts.ino terminus to amino acid 209 of Gal 6 protein may be involved in its couplings to IL-8 receptor.

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.463-469
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• 2012

Atopic dermatitis is a chronic, inflammatory disease of the skin with increased transepidermal water loss. Both an abnormal inflammatory response and a defective skin barrier are known to be involved in the pathogenesis of atopic dermatitis. Protease activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is activated by both trypsin and a specific agonist peptide, SLIGKV-$NH_2$. PAR2 is expressed in suprabasal layers of the epidermis and regulates inflammatory responses and barrier homeostasis. In this study, we show that nordihydroguaiaretic acid (NDGA) inhibits the PAR2-mediated signal pathway and plays a role in skin barrier recovery in atopic dermatitis. Specifically, NDGA reduces the mobilization of intracellular $Ca^{2+}$ in HaCaT keratinocytes by down-regulating inflammatory mediators, such as interleukin-8, thymus and activation-regulated chemokine and intercellular cell adhesion molecule-1 in HaCaT keratinocytes. Also, NDGA decreases the protein expression of involucrin, a differentiation maker of keratinocyte, in both HaCaT keratinocytes and normal human epidermal keratinocytes. We examined NDGA-recovered skin barrier in atopic dermatitis by using an oxazolone-induced atopic dermatitis model in hairless mice. Topical application of NDGA produced an increase in transepidermal water loss recovery and a decrease in serum IgE level, without weight loss. Accordingly, we suggest that NDGA acts as a PAR2 antagonist and may be a possible therapeutic agent for atopic dermatitis.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.93-102
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• 1998

Normal and abnormal follicular growth and steroidogenesis depend on gonadotropins as well as intraovarian peptides, which may mediate or potentiate gonadotropin action. Inhibin also affect follicular development and steroidogenesis and may play a role in dominant follicle selection and follicular atresia. Therefore, we studied the differences of serum inhibin, gonadotropin and androgen levels in the women with only the ultrasound findings and no disorder, and polycystic ovary (PCO) with ovulatory disturbance. We prospectively analysed forty-three women with PCO. The diagnosis of PCO was based on typical appearance of the ovaries on TVS. Twelve women with regular menstrual cycle and normal ovarian morphology were selected as control. Basal levels of inhibin, luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol $(E_2)$, testosterone (T), androstenedione (ADD), dehydroepiandrosterone-sulfate (DS), prolactin and TSH in serum were determined. There were significant differences in basal LH levels and LH/FSH ratio between the control and the women with PCO. The basal levels of inhibin and $E_2$ in the oligo-amenorrheic PCO (N=34) were significantly higher than those in the control. There was higher negative correlation between the inhibin and T levels in the oligo-amenorrheic PCO, but, not in the regular cycling PCO. Also, there was higher positive correlation between the LH and T levels in the oligo-amenorrheic PCO, but not in the regular cycling PCO. These data presume that the initial event of PCO is elevated pituitary LH secretion. Elevated levels of LH may down-regulate LH receptors on granulosa cells and also cause hypertrophy of the thecal layer. High level of androgen secreted by the hypertrophied thecal layer may stimulate inhibin secretion from granulosa cells and can be converted to estrogen by extraovarian tissues and could serve to augment pituitary sensitivity to GnRH with a resultant secretion of more LH than FSH. Inhibin may inhibit FSH action on granulosa cell in the PCO follicle, impairing follicular development and dominant follicle selection resulted in ovulatory disturbance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.477-484
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• 2019

Several types of scavenger receptors, including the Collectin-Placenta 1 (CL-P1) receptorthat is present in mammals, are molecules that are expressed on the surfaces of endothelial cells, macrophages and smooth muscle cells. These molecules are cell surface glycoproteins that can be conjugated to oxidized low density lipoprotein (oxLDL). Among these molecules, the effect of quercetin on CL-P1 activation has been confirmed. Quercetin is known as an antioxidant that stops oxidation because it acts to remove free radicals that are responsible for the oxidation reaction. In this study, fragments from the transcription start site of the mouse CL-P1 gene promoter to the -500th base were cloned using DNA polymerase. These fragments were then introduced into macrophage like RAW264.7 cells and fibroblast-like NIH3T3 cells to study the effect of quercetin on the CL-P1 gene expression. As a result, we found that bases ranging from -250 to -350 in the anterior part where gene expression starts are important for producing CL-P1 protein. Among them, the DNA mutation experiments we performed confirmed that the E2F binding sites are critical for producing the CL-P1 protein? In addition, when quercetin was added to the RAW264.7 culture medium, which was a culture of adherent cells, observedthe phenomenon of the cells falling off from the surface of the culture container.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.10-12
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.