Suppressed estrogen supply via extra-ovarian progesterone receptor membrane component 1 in menopause.

In post-menopausal women, intra-mammary estrogen, which is converted from extra-ovarian estrone (E1), promotes the growth of breast cancer. Since the aromatase inhibitor letrozole does not suppress 17ß-estradiol (E2) production from E1, high intra-mammary E1 concentrations impair letrozole's therapeutic efficacy. Progesterone receptor membrane component 1 (Pgrmc1) is a non-classical progesterone receptor associated with breast cancer progression. In the present study, we introduced a Pgrmc1 heterozygous knockout (hetero KO) murine model exhibiting low Pgrmc1 expression, and observed estrogen levels and steroidogenic gene expression. Naïve Pgrmc1 hetero KO mice exhibited low estrogen (E2 and E1) levels and low progesterone receptor (PR) expression, compared to wild-type mice. In contrast, Pgrmc1 hetero KO mice that have been ovariectomized (OVX), including letrozole-treated OVX mice (OVX-letrozole), exhibited high estrogen levels and PR expression. Increased extra-ovarian estrogen production in Pgrmc1 hetero KO mice was observed with the induction of steroid sulfatase (STS). In MCF-7 cell, letrozole suppressed PR expression, but PGRMC1 knockdown increased PR and STS expression. Our presented results highlight the important role of Pgrmc1 in modulating estrogen production when ovary-derived estrogen is limited, thereby suggesting a potential therapeutic approach for letrozole resistance.

Sex hormone-binding globulin suppresses NAFLD-triggered hepatocarcinogenesis after menopause.

It is generally accepted that androgen receptors increase the risk of hepatocellular carcinoma (HCC), and that estrogen reduces risk of HCC. Many studies regarding this have involved males. We, therefore, have focused our attention on females, especially postmenopausal females, who typically have limited supplies of estrogen. By using sex hormone-binding globulin (SHBG) transgenic mice, we produced a humanoid environment, and facilitated deposition and modulation of sex hormones. After exposure to diethylnitrosamine to induce HCC and upon reaching the age of 40 weeks, mice were fed the fat-rich diet for 5 months. Fat-rich diet fed or ovariectomized (OVX) wild-type mice aged 62 weeks showed HCC progression, whereas fat-rich diet fed SHBG mice or OVX SHBG mice displayed fewer tumors. In the liver of fat-rich diet fed SHBG mice, estrogenic conditions including high levels of 17ß-estradiol and estrogen receptor alpha led to the induction of the lipogenesis inhibitor, phosphorylated acetyl-CoA carboxylase, and consequently suppressed fatty liver. The presence of plasma SHBG in HCC bearing mice suppressed the levels of steatosis and inflammation in a process mediated by estrogens and estrogen receptor alpha. Conversely, in the liver of OVX SHBG mice, lipogenic inhibition was also observed under conditions where the supply of estrogens is limited. Through in vitro experiment, it was confirmed SHBG suppresses lipogenesis via inhibition of acetyl-CoA carboxylase level. In conclusion, our results show that plasma SHBG might have a clinical impact on lipid-mediated hepatic diseases.

Dietary intake of genistein suppresses hepatocellular carcinoma through AMPK-mediated apoptosis and anti-inflammation.

BACKGROUND: Women have a lower risk of hepatocellular carcinoma (HCC) than men, and the decreased possibility of HCC in women is thought to depend on estrogen levels. As a soybean-isoflavone product, genistein has estrogenic activity in various reproductive tissues, because it mimics 17ß-estradiol and binds the estrogen receptor. Though genistein is a known liver cancer suppressor, its effects have not been studies in long-term experiment, where genistein is fed to a female animal model of HCC. METHODS: Mice were treated with diethylnitrosamine (DEN) to induce HCC at 2 weeks of age and fed with supplemental genistein for 5 months, from 40 to 62 weeks of age. RESULTS: The dietary intake of genistein decreased the incidence of HCC and suppressed HCC development. Genistein induced phospho-AMPK in total liver extracts, Hep3B cells, and Raw 264.7 cells, and phospho-AMPK promoted apoptosis in liver and Hep3B cells. Moreover, phospho-AMPK down-regulated pro-inflammatory responses and ameliorated liver damage. A suppressed pro-inflammatory response with increased mitochondrial respiration was concomitantly observed after genistein treatment. CONCLUSIONS: Genistein-mediated AMPK activation increases hepatocyte apoptosis through energy-dependent caspase pathways, suppresses the inflammatory response in resident liver macrophages by increased cellular respiration, and consequently inhibits the initiation and progression of HCC.

Molecular Identification of Sarcocystis grueneri in Wild Korean Water Deer (Hydropotes inermis argyropus).

The cysts of Sarcocystis grueneri were detected and characterized from the cardiac muscles of the Korean water deer (Hydropotes inermis argyropus). Of the 38 heart muscle samples examined by light microscopy, 10 were found infected with the cysts of Sarcocystis sp. The cysts appeared oval to spherical shape and measured 110-380 µm in length and 90-170 µm in width. A phylogenetic tree of the 18S rRNA sequences (1.5 kb) revealed a close relationship of the infected cysts to genus Sarcocystis. The 18S rRNA sequence of the infected cysts showed 100% identity to S. grueneri and 97% to S. capracanis. Here, we first report the S. grueneri infections in the Korean water deer.

Red ginseng ameliorates acute cisplatin-induced nephropathy.

Korean red ginseng is one of the traditional herbal medicines most widely used in China, Korea, and Japan. To determine whether Korean red ginseng extract can mitigate acute renal nephropathy, we examined its renoprotective effects in a model of cisplatin-induced acute renal failure in Sprague Dawley rats. Korean red ginseng was administered to rats by oral gavage once a day at doses of 100, 300, or 500 mg/kg for 28 days. On day 23, the animals received an intraperitoneal injection of cisplatin (5 mg/kg) to induce acute renal failure. Body weight gain, urine volume, blood urea nitrogen and creatinine concentrations, and expression of p53 were measured. Terminal deoxynucleotidyl transferase dUTP nick end-labeling was used to analyze apoptosis. Kidney tissues from the control and experimental groups were analyzed by immunohistochemistry for inflammatory cytokines and histopathological examination. To identify the mechanism responsible for the renoprotective effects of Korean red ginseng, we measured malondialdehyde concentration as an end product of lipid peroxidation and the activities of the antioxidants superoxide dismutase and glutathione. Korean red ginseng significantly decreased the levels of indicators of renal dysfunction, inflammatory cytokine expression, apoptosis, and malondialdehyde content in the kidney and also significantly attenuated the histopathological changes associated with acute renal failure. These findings suggest that Korean red ginseng has renoprotective effects against cisplatin-induced acute renal failure by reducing oxidative stress and inflammation.

Immunotoxicity of zinc oxide nanoparticles with different size and electrostatic charge.

While zinc oxide (ZnO) nanoparticles (NPs) have been recognized to have promising applications in biomedicine, their immunotoxicity has been inconsistent and even contradictory. To address this issue, we investigated whether ZnO NPs with different size (20 or 100 nm) and electrostatic charge (positive or negative) would cause immunotoxicity in vitro and in vivo, and explored their underlying molecular mechanism. Using Raw 264.7 cell line, we examined the immunotoxicity mechanism of ZnO NPs as cell viability. We found that in a cell viability assay, ZnO NPs with different size and charge could induce differential cytotoxicity to Raw 264.7 cells. Specifically, the positively charged ZnO NPs exerted higher cytotoxicity than the negatively charged ones. Next, to gauge systemic immunotoxicity, we assessed immune responses of C57BL/6 mice after oral administration of 750 mg/kg/day dose of ZnO NPs for 2 weeks. In parallel, ZnO NPs did not alter the cell-mediated immune response in mice but suppressed innate immunity such as natural killer cell activity. The CD4(+)/CD8(+) ratio, a marker for matured T-cells was slightly reduced, which implies the alteration of immune status induced by ZnO NPs. Accordingly, nitric oxide production from splenocyte culture supernatant in ZnO NP-fed mice was lower than control. Consistently, serum levels of pro/anti-inflammatory (interleukin [IL]-1ß, tumor necrosis factor-α, and IL-10) and T helper-1 cytokines (interferon-γ and IL-12p70) in ZnO NP-fed mice were significantly suppressed. Collectively, our results indicate that different sized and charged ZnO NPs would cause in vitro and in vivo immunotoxicity, of which nature is an immunosuppression.

Chordoma in the tail of a ferret.

A chordoma is an uncommon tumor that originates from the remnants of the notochord and most commonly involves the cranial and caudal regions of the axial skeleton. Chordoma has been described in laboratory animals such as dogs, rats, minks, and ferrets. This report describes a case of a chordoma in the tail of a ferret. Grossly, a grayish-white, expansile, subcutaneous soft-tissue mass was observed in the tail. Histopathologically, the mass was a loosely placed, nodular, unencapsulated neoplasm within the dermis. In the mass, tumor lobules were intermingled with fibrous tissues. Fibrous tissues contained abundant extracellular basophilic material that was consistent with mucin. The tumor was composed of a close pack of adipocyte-like vacuolated cells (physaliferous cells). The cells were centrally or eccentrically located round nuclei and eosinophilic cytoplasm with large vacuoles. Immunohistologically, neoplastic cells were positive for vimentin and S-100 protein. Based on histopathologic findings and special staining characteristics, this case was diagnosed as chordoma.

COMP-Ang1, a variant of angiopoietin 1, inhibits serum-deprived apoptosis of mesenchymal cells via PI3K/Akt and mitogen-activated protein kinase pathways.

BACKGROUND/AIMS: Cartilage oligomeric matrix protein (COMP)-angiopoietin 1 (Ang1) is a soluble and stable form of Ang1 which plays important roles in vessel formation and the survival of endothelial cells, neurons and cardiomyocytes. However, the effects of COMP-Ang1 on the survival of mesenchymal cells are unknown. Mesenchymal cells have been transplanted with some scaffolds for bone tissue regeneration, but they occasionally underwent cell death due to a lack of nutrient supply. This study examined the effects of COMP-Ang1 on the survival of mesenchymal cells under nutrient-deprived conditions. METHODS: Primary and C3H10T1/2 mesenchymal cells were cultured under serum deprivation with or without COMP-Ang1. The effects of COMP-Ang1 on mesenchymal cell survival and its molecular mechanism were determined using a viability test, RT-PCR, Western blotting and fluorescence-activated cell sorting analysis. RESULTS AND CONCLUSION: COMP-Ang1 inhibited the nutrient-deprived apoptotic cell death of mesenchymal cells through the Akt, p38 and extracellular-signal-regulated kinase (ERK) pathways. In addition, COMP-Ang1 reversed the nutrient-deprived suppression of cyclin D1 mRNA expression. These results suggest that COMP-Ang1 has a protective role in the survival of nutrient-deprived mesenchymal cells. The use of COMP-Ang1 with some scaffolds might be useful for bone tissue engineering.

Applications of chitin and its derivatives in biological medicine.

Chitin and its derivatives-as a potential resource as well as multiple functional substrates-have generated attractive interest in various fields such as biomedical, pharmaceutical, food and environmental industries, since the first isolation of chitin in 1811. Moreover, chitosan and its chitooligosaccharides (COS) are degraded products of chitin through enzymatic and acidic hydrolysis processes; and COS, in particular, is well suited for potential biological application, due to the biocompatibility and nontoxic nature of chitosan. In this review, we investigate the current bioactivities of chitin derivatives, which are all correlated with their biomedical properties. Several new and cutting edge insights here may provide a molecular basis for the mechanism of chitin, and hence may aid its use for medical and pharmaceutical applications.

Actin disruption inhibits hypoxia inducible factor-1α expression via inactivity of Mdm2-mediated p70S6K.

The intracellular actin cytoskeleton is a central player in tumor cell migration and adhesion, and interacts with the extracellular matrix during the progression to metastasis. Although recent reports on motility events have revealed that the destabilization of actin affects cancer progression and hypoxia inducible factor-1α (HIF-1α) activity, little is known about the responsive activity of HIF-1α following actin disruption. Here, we demonstrate that the inhibition of actin polymerization or depolymerization attenuates HIF-1α expression independently of proteasomal degradation. The disruption of actin dynamics inactivates HIF-1α translational expression through p70S6K translational signaling; this is independent of p53 activation, suggesting that actin dysfunction-mediated HIF-1α destabilization may lead to the development of novel anticancer chemotherapeutic targets.

Siglecg limits the size of B1a B cell lineage by down-regulating NFkappaB activation.

BACKGROUND: B1 B cells are believed to be a unique lineage with a distinct developmental pathway, function and activation requirement. How this lineage is genetically determined remained largely obscure. METHODS AND PRINCIPAL FINDINGS: Using the Siglecg-deficient mice with a knockin of green-fluorescent protein encoding sequence, we show here that, although the Siglecg gene is broadly expressed at high levels in all stages and/or lineages of B cells tested and at lower levels in other lineages, its deletion selectively expanded the B1a B cell lineages, including the frequency of the B1 cell progenitor in the bone marrow and the number of B1a cells in the peritoneal cavity, by postnatal expansion. The expansion of B1a B cells in the peritoneal correlated with enhanced activation of NFkappaB and was ablated by an IKK inhibitor. CONCLUSION AND SIGNIFICANCE: Our data revealed a critical role for Siglec G-NFkappaB pathway in regulating B1a B cell lineage. These data lead to a novel model of B1a lineage development that explains a large array of genetic data in this field.

FOXP3 is an X-linked breast cancer suppressor gene and an important repressor of the HER-2/ErbB2 oncogene.

The X-linked Foxp3 is a member of the forkhead/winged helix transcription factor family. Germline mutations cause lethal autoimmune diseases in males. Serendipitously, we observed that female mice heterozygous for the "scurfin" mutation of the Foxp3 gene (Foxp3(sf/+)) developed cancer at a high rate. The majority of the cancers were mammary carcinomas in which the wild-type Foxp3 allele was inactivated and HER-2/ErbB2 was overexpressed. Foxp3 bound and repressed the HER-2/ErbB2 promoter. Deletion, functionally significant somatic mutations, and downregulation of the FOXP3 gene were commonly found in human breast cancer samples and correlated significantly with HER-2/ErbB2 overexpression, regardless of the status of HER-2 amplification. Our data demonstrate that FOXP3 is an X-linked breast cancer suppressor gene and an important regulator of the HER-2/ErbB2 oncogene.

NF-kappaB in breast cancer cells promotes osteolytic bone metastasis by inducing osteoclastogenesis via GM-CSF.

Advanced breast cancers frequently metastasize to bone, resulting in osteolytic lesions, yet the underlying mechanisms are poorly understood. Here we report that nuclear factor-kappaB (NF-kappaB) plays a crucial role in the osteolytic bone metastasis of breast cancer by stimulating osteoclastogenesis. Using an in vivo bone metastasis model, we found that constitutive NF-kappaB activity in breast cancer cells is crucial for the bone resorption characteristic of osteolytic bone metastasis. We identified the gene encoding granulocyte macrophage-colony stimulating factor (GM-CSF) as a key target of NF-kappaB and found that it mediates osteolytic bone metastasis of breast cancer by stimulating osteoclast development. Moreover, we observed that the expression of GM-CSF correlated with NF-kappaB activation in bone-metastatic tumor tissues from individuals with breast cancer. These results uncover a new and specific role of NF-kappaB in osteolytic bone metastasis through GM-CSF induction, suggesting that NF-kappaB is a potential target for the treatment of breast cancer and the prevention of skeletal metastasis.

Proteasome inhibitor PS-341 induces apoptosis in cisplatin-resistant squamous cell carcinoma cells by induction of Noxa.

Cisplatin is one of the most common DNA-damaging agents used for treating patients with solid tumors such as squamous cell carcinoma (SCC). Unfortunately, significant levels of resistance in SCC cells emerge rapidly following cisplatin treatment. Here we report that the proteasome inhibitor PS-341, the representative of a new class of chemotherapeutic drugs, was capable of inducing apoptosis in cisplatin-resistant SCC cells via the endoplasmic reticulum stress. PS-341 stimulated the phosphorylation of PERK and the unfolded protein response, resulting in the induction of the transcription factor ATF-4. Importantly, the Bcl-2 homology domain 3-only (BH3-only) protein Noxa was found to be strongly induced in cisplatin-resistant SCC cells by PS-341 but not by cisplatin. The knock-down of Noxa using small interference RNA significantly abolished PS-341-mediated apoptosis in SCC cells. Using eIF2alpha mutant mouse embryonic fibroblasts, we found that functional eIF2alpha played an essential role in PS-341-induced Noxa expression. Taken together, our novel findings reveal a direct link between PS-341-induced endoplasmic reticulum stress and the mitochondria-dependent apoptotic pathway and suggest that PS-341 may be utilized for overcoming cisplatin-resistance in human SCC.

Cloning and expression of 51-kDa antigenic protein of Neorickettsia risticii NR-JA1.

Neorickettsia (Ehrlichia) risticii is a causative agent of acute diarrheal syndrome in horses, commonly known as Potomac horse fever. Korean isolate of N. risticii NR-JA1 was cultivated in mouse macrophage cell line P388D1. A complete ORF of p51 antigenic protein gene was amplified and cloned into pQE32 and pcDNA3.1 vectors and the resultant clones were named as pQE32/Nr-51 and pcDNA3.1/Nr-51, respectively. Recombinant p51 (rp51) protein antigen was expressed in E. coli (pQE32/Nr-51) and cos-7 cell line (pcDNA3.1/Nr-51). The rp51 protein showed immunoreactivity with anti- mouse p51 antibodies. BALB/c mice were inoculated with recombinant plasmid DNA (pcDNA3.1/Nr-51). The serum samples collected from these BALB/c mice showed IgG ELISA titers of 1:128. In a Western immunoblot assay, these serum samples showed a strong reactivity to rp51 expressed in cos-7 cell line transfected with pcDNA3.1/Nr-51. The results of this preliminary indicate that N. risticii p51 protein is an immmuno-dominant antigen and may be a good target for the development of serological or a molecular diagnostic test and possibly an improved recombinant DNA based vaccine against Potomac horse fever.