Interleukin-1B-31 gene polymorphism in Hakka gastric cancer patients in Guangdong, China.

The aim of this study was to examine the interleukin-1B (IL-1B) gene promoter region -31 (IL-1B-31) polymorphism distribution characteristic of Hakka gastric cancer patients in Guangdong Province and to explore its association with gastric cancer. We used the 1:1 case-control method, matrix-assisted laser desorption ionization flight time mass spectrometry, and MassARRAY-IPLEX technology to genotype IL-1B-31 (-31C> T) in 52 Hakka gastric cancer patients and 52 Hakka control subjects in Meizhou. Three genotypes - CT, TT, and CC - of IL-1B-31 were found in the Meizhou Hakka population. Their distribution frequencies in the gastric cancer group were 40.38, 40.38, and 19.23%, respectively, whereas the frequencies in control subjects were 57.69, 17.31, and 25.00%, respectively. The differences in frequency distributions of the genotypes between the 2 groups were statistically significant (chi-square = 6.78, P < 0.05). Subjects with the TT genotype had a higher risk of gastric cancer compared with that in subjects carrying the CT genotype (odds ratio = 2.857, 95% confidence interval = 1.114-7.328). This risk was more apparent in male subjects. IL-1B-31 locus polymorphism may be associated with gastric cancer susceptibility in this population, but additional studies with larger sample size are needed to confirm the conclusions.

A potential role for interleukin-15 in the regulation of human natural killer cell survival.

Resting lymphocyte survival is dependent upon the expression of Bcl-2, yet the factors responsible for maintaining lymphocyte Bcl-2 protein expression in vivo are largely unknown. Natural killer (NK) cells are bone marrow-derived lymphocytes that constitutively express the beta and common gamma(c) subunits of the IL-2 receptor (R) as a heterodimer with intermediate affinity for IL-2. IL-15 also binds to IL-2Rbeta gamma(c) and is much more abundant in normal tissues than IL-2. Mice that lack the IL-2 gene have NK cells, whereas mice and humans that lack IL-2R gamma(c) do not have NK cells. Further, treatment of mice with an antibody directed against IL-2Rbeta results in a loss of the NK cell compartment. These data suggest that a cytokine other than IL-2, which binds to IL-2Rbeta gamma(c), is important for NK cell development and survival in vivo. In the current report, we show that the recently described IL-15R(alpha) subunit cooperates with IL-2Rbeta gamma(c) to transduce an intracellular signal at picomolar concentrations of IL-15. We demonstrate that resting human NK cells express IL-15R(alpha) mRNA and further, that picomolar amounts of IL-15 can sustain NK cell survival for up to 8 d in the absence of serum. NK cell survival was not sustained by other monocyte-derived factors (i.e., TNF-alpha, IL-1beta, IL-10, IL-12) nor by cytokines known to use gamma(c) for signaling (i.e., IL-4, IL-7, IL-9, IL- 13). One mechanism by which IL-15 promotes NK cell survival may involve the maintenance of Bcl-2 protein expression. Considering these functional properties of IL-15 and the fact that it is produced by bone marrow stromal cells and activated monocytes, we propose that IL-15 may function as an NK cell survival factor in vivo.

Genomic modelling of the ESR1 Y537S mutation for evaluating function and new therapeutic approaches for metastatic breast cancer.

Drugs that inhibit estrogen receptor-α (ER) activity have been highly successful in treating and reducing breast cancer progression in ER-positive disease. However, resistance to these therapies presents a major clinical problem. Recent genetic studies have shown that mutations in the ER gene are found in >20% of tumours that progress on endocrine therapies. Remarkably, the great majority of these mutations localize to just a few amino acids within or near the critical helix 12 region of the ER hormone binding domain, where they are likely to be single allele mutations. Understanding how these mutations impact on ER function is a prerequisite for identifying methods to treat breast cancer patients featuring such mutations. Towards this end, we used CRISPR-Cas9 genome editing to make a single allele knock-in of the most commonly mutated amino acid residue, tyrosine 537, in the estrogen-responsive MCF7 breast cancer cell line. Genomic analyses using RNA-seq and ER ChIP-seq demonstrated that the Y537S mutation promotes constitutive ER activity globally, resulting in estrogen-independent growth. MCF7-Y537S cells were resistant to the anti-estrogen tamoxifen and fulvestrant. Further, we show that the basal transcription factor TFIIH is constitutively recruited by ER-Y537S, resulting in ligand-independent phosphorylation of Serine 118 (Ser118) by the TFIIH kinase, cyclin-dependent kinase (CDK)7. The CDK7 inhibitor, THZ1 prevented Ser118 phosphorylation and inhibited growth of MCF7-Y537S cells. These studies confirm the functional importance of ER mutations in endocrine resistance, demonstrate the utility of knock-in mutational models for investigating alternative therapeutic approaches and highlight CDK7 inhibition as a potential therapy for endocrine-resistant breast cancer mediated by ER mutations.

Nerve growth factor activates persistent Rap1 signaling in endosomes.

We investigated a role for endogenous Rap1, a small monomeric GTP-binding protein of the Ras family, in nerve growth factor (NGF) signaling in PC12 cells. Although both epidermal growth factor (EGF) and NGF caused transient activation of Ras, only NGF induced the activation of Rap1. Moreover, Rap1 activation was sustained for hours, an effect that matched the sustained activation of the mitogen-activated protein kinase (MAPK) pathway. To investigate the molecular basis for Rap1 activation, we examined complexes containing C3G, a guanine nucleotide exchange factor for Rap1, and CrkL, an adapter protein known to influence Rap1 signaling. NGF induced the formation of a long-lived complex containing C3G/CrkL/Shp2/Gab2/TrkA. Linking the complex to Rap1 activation, we coprecipitated activated TrkA and activated MAPK with activated Rap1 in NGF-treated cells. Confocal microscopy and subcellular fractionation showed that activated Rap1 and the other proteins of the signaling complex were present in endosomes. Pretreatment of PC12 cells with brefeldin A (BFA), which disrupts the Golgi and endosomal compartments, had little effect on Ras activation but strongly inhibited NGF-induced Rap1 activation and continuing MAPK activation. We propose that endosomes are a site from which NGF induces the prolonged activation of Rap1 and MAPK.

Bone mineralization and osteoblast differentiation are negatively modulated by integrin alpha(v)beta3.

Numerous bone matrix proteins can interact with alpha(v)-containing integrins including alpha(v)beta3. To elucidate the net effects of the interaction between these proteins and alpha(v)beta3 on osteoblast function, we developed a murine osteoblastic cell line that overexpressed human alpha(v)beta3. Human alpha(v)beta3-integrin was expressed on cell membrane, in which its presence did not alter the surface level of endogenous mouse alpha(v)beta3. The expressed human alpha(v)beta3 was functional because cell adhesion to osteopontin was increased and this increment was abolished by antibody against human alpha(v)beta3. The proliferation rate of cells overexpressing alpha(v)beta3 (alpha(v)beta3-cells) was increased whereas matrix mineralization was decreased. To elucidate the mechanisms leading to inhibition of matrix mineralization, the expression of proteins important for mineralization was analyzed. Alkaline phosphatase activity and the expression of osteocalcin, type I collagen, and bone sialoprotein (BSP) were decreased whereas osteopontin was stimulated in alpha(v)beta3-cells. The regulation of osteopontin, osteocalcin, and BSP expression was mediated via transcriptional mechanism because their promoter activities were altered. Examination of molecules involved in integrin signaling indicated that activator protein-1 (AP-1) and extracellular signal-regulated kinase (Erk) activities were enhanced whereas c-jun N-terminal kinase (JNK) activity was decreased in alpha(v)beta3-cells. The activity of p38 and the levels of focal adhesion kinase (FAK) and vinculin were not altered. Moreover, the adhesions of alpha(v)beta3-cells to type I collagen and fibronectin were inhibited, which was attributed to decreased beta1-integrin levels on cell surface. In conclusion, overexpressing alpha(v)beta3-integrin in osteoblasts stimulated cell proliferation but retarded differentiation, which were derived via altered integrin-matrix interactions, signal transduction, and matrix protein expression.

In Vitro andIn Vivo induction of bone formation using a recombinant adenoviral vector carrying the human BMP-2 gene.

It has been well established that bone morphogenetic protein-2 (BMP-2) can induce bone formation bothin vivo andin vitro, although high concentrations (up to milligrams) of BMP-2 have been required to achieve this effectin vivo. Further, clinical applications are usually limited to a single dose at the time of implantation. In an attempt to prolong the transforming effect of BMP-2 we used a recombinant adenoviral vector carrying the human BMP-2 gene (Adv-BMP2) to transduce marrow-derived mesenchymal stem cells (MSC) of skeletally mature male New Zealand white rabbits. The pluripotential MSC were incubated with Adv-BMP2 overnight followed by culture in growth medium for 1 week. Assays on tissue cultures demonstrated that these Adv-BMP2 transduced MSC produced BMP-2 protein, differentiated into an osteoprogenitor line, and induced bone formationin vitro. These MSC had increased alkaline phosphatase activity, increased expression of type I collagen, osteopontin, and osteocalcin mRNA, and induced matrix mineralization compared with both nontransduced cells and cells transduced with a control adenoviral construct. To analyze the osteogenic potentialin vivo, Adv-BMP2-transduced MSC were autologously implanted into the intertransverse process space between L5 and L6 of the donor rabbits. The production of new bone was demonstrated by radiographic examination 4 weeks later in areas implanted with cells transduced with Adv-BMP2, whereas no bone was evident at sites implanted with cells transduced with the control adenoviral construct. Histological examination further confirmed the presence of new bone formation. These accumulated data indicate that it is possible to successfully transduce mesenchymal stem cells with a recombinant adenoviral vector carrying the gene for BMP-2 such that these cells will produce BMP-2, differentiate into an osteoprogenitor line, and induce bone formation bothin vitro andin vivo. Moreover, incubation of the Adv-BMP2-transduced cells for an additional 7 days in culture before transplantation enhances the success rate in bone formation (three out of three) as compared with our previous report (one out of five, Calcif Tissue Int 63:357-360, 1998).

Cervical human papilloma virus infection of women attending social hygiene clinics in Hong Kong.

OBJECTIVE: To find the prevalence of HPV infection in women attending a sexually transmitted disease clinic in Hong Kong. METHOD: Cervical HPV infection was identified by cervical cytology and DNA filter in-situ-hybridization (Virapap) techniques in 207 women attending a social hygiene clinic. Other risk factors for cervical cancer were assessed and any association with HPV infection was sought. Statistical analysis was carried out using the chi 2-test. RESULT: The prevalence of HPV infection in the 207 Chinese women was 8.2% by cervical smear and 12.6% by DNA filter in-situ-hybridization. Risk factors for cervical cancer were not significantly associated with HPV infection in this group, 95% of whom were prostitutes. CONCLUSION: The prevalence of HPV infection in this group at high risk for cervical cancer is higher than in low-risk pregnant women, however the prevalence of HPV infection in Hong Kong is at the low end of the range of figures quoted for Caucasians. The cause of such a low prevalence is yet to be determined.

Necrolytic migratory erythema in glucagonoma syndrome.

A 32-year-old female Chinese presenting with typical features of necrolytic migratory erythema due to glucagonoma syndrome is reported. The clinical, biochemical, histopathological, and electron-microscopic findings are described. Various different aspects of this rare entity are discussed.

High output cardiac failure in a parturient with hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia is a genetic condition which results in arteriovenous malformations involving the skin, mucous membranes, lung, brain, gastrointestinal tract, liver and spinal canal. The shunting of blood through arteriovenous malformations, especially in the liver,; leads to maldistribution of cardiac output. In order to supply blood to vital organs, cardiac output is increased through vasodilation, elevated stroke volume and elevated heart rate. Pregnancy can worsen the effects of the arteriovenous malformations. We present the peripartum management of a woman with hereditary haemorrhagic telangiectasia predominantly involving the liver that resulted in high output cardiac failure during two consecutive pregnancies.

Elevated C-reactive protein level in hemodialysis patients with moderate/severe uremic pruritus: a potential mediator of high overall mortality.

BACKGROUND: Dialysis patients with uremic pruritus have worse outcomes. However, the pathophysiology of the high mortality in these patients remains inconclusive except for links with calcium/phosphate imbalance and sleep disturbance. Whether inflammation, an outcome predictor in dialysis patients, plays a role is unknown. METHODS: This prospective study included 321 chronic hemodialysis (HD) patients (>3 months) for survival analysis. A visual analog scale (VAS) was used to measure the severity of itching, and the patients were divided into four groups: no pruritus (VAS = 0, N = 118), mild (VAS 1-3, N = 76), moderate (VAS 4-7, N = 89) and severe pruritus (VAS 8-10, N = 38). The Pittsburgh Sleep Quality Index (PSQI) was used to define sleep disturbance, while high-sensitive C-reactive protein (hs-CRP) and tumor necrosis factor α (TNF-α) were used to evaluate inflammation. The patients were followed-up for 30 months. RESULTS: Patients with moderate/severe pruritus had higher hs-CRP, but similar TNF-α levels; they also had a worse survival rate (P = 0.0197, log rank test). By stratifying hs-CRP levels, those with higher hs-CRP had worse survival regardless of the severity of uremic pruritus. In a Cox proportional hazard model, hs-CRP levels and moderate/severe uremic pruritus were independent predictors of mortality after adjusting for age, poor sleeper (PSQI > 5), diabetes, albumin, phosphate, hemoglobin and parathyroid hormone levels and (hs-CRP) × (moderate/severe uremic pruritus) (all P < 0.05). CONCLUSION: In moderate/severe pruritic HD patients, those with higher hs-CRP suffer from worse overall mortality. Inflammation may bridge uremic pruritus to high mortality, and elevated hs-CRP predicts a worse outcome in this population.

Enhanced light output from a nitride-based power chip of green light-emitting diodes with nano-rough surface using nanoimprint lithography.

Enhanced light extraction from a GaN-based power chip (PC) of green light-emitting diodes (LEDs) with a rough p-GaN surface using nanoimprint lithography is presented. At a driving current of 350 mA and with a chip size of 1 mm × 1 mm packaged on transistor outline (TO)-cans, the light output power of the green PC LEDs with nano-rough p-GaN surface is enhanced by 48% when compared with the same device without a rough p-GaN surface. In addition, by examining the radiation patterns, the green PC LED with nano-rough p-GaN surface shows stronger light extraction with a wider view angle. These results offer promising potential to enhance the light output powers of commercial light-emitting devices by using the technique of nanoimprint lithography under suitable nanopattern design.

Interleukin-1 beta induces production of granulocyte colony-stimulating factor in human hepatoma cells.

Interleukin-1 (IL-1) is a proinflammatory cytokine that participates in the activation of the acute-phase plasma protein genes in hepatic cells during infection and injury. In human hepatoma HepG2 and Hep3B cells, IL-1 beta induced production of the granulocyte colony-stimulating factor (G-CSF) in a dose-dependent manner. Activation of G-CSF gene expression was an early and transient response. In HepG2 cells, G-CSF mRNA was strongly upregulated 2 hours after IL-1 beta treatment and returned to the pretreatment level by 6 hours. The secreted G-CSF was biologically active, as shown by the induction of gene transcription through the G-CSF receptor. Maximal G-CSF activity released to culture medium occurred after 8 hours. Previous studies have shown that liver expression of G-CSF was augmented in mice challenged by inflammatory stimuli. Our data suggest that IL-1 beta mediates, at least in part, this cytokine activation program in parenchymal cells and that liver-derived G-CSF may contribute to the regulation of hematopoiesis during the acute-phase response.

The purified 14-kilodalton envelope protein of vaccinia virus produced in Escherichia coli induces virus immunity in animals.

Vaccinia virus (VV) was successfully used as a live vaccine to eradicate smallpox, but the nature of viral proteins involved in eliciting viral immunity has not yet been identified. A potential candidate is a 14-kDa VV envelope protein that is involved in virus penetration at the level of virus-cell fusion, in cell-cell fusion late in infection, and in virus dissemination. The 14-kDa envelope protein has been produced in Escherichia coli, with properties similar to those of the native protein found in the virus particle and in infected cells (C. Lai, S. Gong, and M. Esteban, J. Biol. Chem. 256:22174-22180, 1990). In this investigation, we showed that mice immunized with purified VV 14-kDa protein synthesized in E. coli in the form of a monomer or a trimer develop high-titer neutralizing antibodies and are protected when challenged with lethal doses of wild-type VV. Our findings demonstrate that it is possible to confer protection against VV through immunization with the 14-kDa envelope protein.

Vaccinia virus induces cell fusion at acid pH and this activity is mediated by the N-terminus of the 14-kDa virus envelope protein.

The mechanism by which the large-size poxviruses enter animal cells is not known. In this investigation we show that acid pH treatment of wild-type vaccinia virus-infected cells triggers strong fusion of cells in culture, with an optimum at pH 4.8. We have identified the virus-induced fusion protein as a 14-kDa envelope protein, based on the ability of a 14-kDa specific monoclonal antibody (mAbC3) to block vaccinia virus-induced fusion-from-within and fusion-from-without. We provide genetic evidence for a role of the 14-kDa protein in cell fusion, since insertion of the 14-kDa encoding gene into the genome of nonfusogenic mutant viruses generates heterozygous viruses that now acquire acid pH-dependent fusion activity. DNA sequence analyses of the 14-kDa encoding gene of the mutant viruses, 65-16 and 101-14, reveal N-terminal deletions of 46 and 10 amino acids, respectively. These deletions remove a small hydrophobic region at the N-terminus of the 14-kDa protein and prevent fusion. Our findings demonstrate that vaccinia virus can induce strong fusion of cells in culture at acid pH implying some entry of the virus by endocytosis, that the 14-kDa virus envelope protein is the fusogenic protein, and that the N-terminal proximal region is involved in fusion.

Structural and functional properties of the 14-kDa envelope protein of vaccinia virus synthesized in Escherichia coli.

Vaccinia virus is a highly cytocidal virus, but the steps that lead to virus penetration into cells, the first event in virus pathogenesis, have not been elucidated. We have shown that a 14-kDa envelope protein of vaccinia virus might play a major role in virus-penetration acting at the level of cell fusion (Rodriguez, J. F., Paez, E., and Esteban, M. (1987) J. Virol. 61, 395-404; Gong, S., Lai, C., and Esteban, M. (1990) Virology 178, 81-91). To carry out structural and functional studies on the vaccinia 14-kDa protein, it would be desirable to have a high level expression system, since the amount of protein that can be obtained from purified virus or from infected cells is very limited. In this investigation we demonstrate that the 14-kDa envelope protein of vaccinia virus is expressed in Escherichia coli in soluble form and at high levels. We establish, by several criteria, that the 14-kDa vaccinia virus protein expressed in E. coli is similar to the protein found in the virus particle based on apparent molecular mass, occurrence of disulfide-linked oligomers, reactivity against specific monoclonal antibody, and identity in amino-terminal sequence with the predicted DNA sequence of the gene. We define several structural and functional properties concerning the 14-kDa envelope protein of vaccinia virus. 1) 14 kDa is a trimer of identical subunits. 2) A monomer binds to itself more strongly than to a dimer or a trimer. 3) Oligomerization does not require cellular factors. 4) Trimers induce high titer neutralizing antibodies in animals which correlate with overall immunogenicity. 5) 14-kDa binds with specificity to the cell surface of cultured cells.