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Eisen T, Ahmad T, Flaherty KT, Gore M, Kaye S, Marais R, Gibbens I, Hackett S, James M, Schuchter LM, Nathanson KL, Xia C, Simantov R, Schwartz B, Poulin-Costello M, O'Dwyer PJ, Ratain MJ. Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis. Br J Cancer 2006; 95:581-6. [PMID: 16880785 PMCID: PMC2360687 DOI: 10.1038/sj.bjc.6603291] [Citation(s) in RCA: 470] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The effects of sorafenib – an oral multikinase inhibitor targeting the tumour and tumour vasculature – were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with ⩾25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with ⩾25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had ⩾25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had ⩾25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease stability. DNA was extracted from the biopsies of 17/22 patients. Six had V600E-positive tumours (n=4 had PD; n=1 had SD; n=1 unevaluable for response), and 11 had tumours containing wild-type BRAF (n=9 PD; n=1 SD; n=1 unevaluable for response). In conclusion, sorafenib is well tolerated but has little or no antitumour activity in advanced melanoma patients as a single agent at the dose evaluated (400 mg b.i.d.). Ongoing trials in advanced melanoma are evaluating sorafenib combination therapies.
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Randomized Controlled Trial |
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Xia C, Kwok CY, Nazar LF. A high-energy-density lithium-oxygen battery based on a reversible four-electron conversion to lithium oxide. Science 2018; 361:777-781. [DOI: 10.1126/science.aas9343] [Citation(s) in RCA: 241] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 07/10/2018] [Indexed: 11/02/2022]
Abstract
Lithium-oxygen (Li-O2) batteries have attracted much attention owing to the high theoretical energy density afforded by the two-electron reduction of O2 to lithium peroxide (Li2O2). We report an inorganic-electrolyte Li-O2 cell that cycles at an elevated temperature via highly reversible four-electron redox to form crystalline lithium oxide (Li2O). It relies on a bifunctional metal oxide host that catalyzes O–O bond cleavage on discharge, yielding a high capacity of 11 milliampere-hours per square centimeter, and O2 evolution on charge with very low overpotential. Online mass spectrometry and chemical quantification confirm that oxidation of Li2O involves transfer of exactly 4 e–/O2. This work shows that Li-O2 electrochemistry is not intrinsically limited once problems of electrolyte, superoxide, and cathode host are overcome and that coulombic efficiency close to 100% can be achieved.
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Ma D, Xia C. CuI-catalyzed coupling reaction of beta-amino acids or esters with aryl halides at temperature lower than that employed in the normal Ullmann reaction. Facile synthesis of SB-214857. Org Lett 2001; 3:2583-6. [PMID: 11483066 DOI: 10.1021/ol016258r] [Citation(s) in RCA: 201] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] The CuI-catalyzed coupling reaction of aryl halides with beta-amino acids or beta-amino esters is completed at 100 degrees C in 48 h, which indicates that the structure of the beta-amino acid has an accelerating effect for the Ullmann-type aryl amination reaction. This coupling reaction can be used to prepare enantiopure N-aryl beta-amino acids. An efficient synthetic route to SB214857, a potent GPIIb/IIIa receptor antagonist, is developed using this method.
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Patnaik A, Appleman LJ, Tolcher AW, Papadopoulos KP, Beeram M, Rasco DW, Weiss GJ, Sachdev JC, Chadha M, Fulk M, Ejadi S, Mountz JM, Lotze MT, Toledo FGS, Chu E, Jeffers M, Peña C, Xia C, Reif S, Genvresse I, Ramanathan RK. First-in-human phase I study of copanlisib (BAY 80-6946), an intravenous pan-class I phosphatidylinositol 3-kinase inhibitor, in patients with advanced solid tumors and non-Hodgkin's lymphomas. Ann Oncol 2017; 27:1928-40. [PMID: 27672108 PMCID: PMC5035790 DOI: 10.1093/annonc/mdw282] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 07/06/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND To evaluate the safety, tolerability, pharmacokinetics, and maximum tolerated dose (MTD) of copanlisib, a phosphatidylinositol 3-kinase inhibitor, in patients with advanced solid tumors or non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS Phase I dose-escalation study including patients with advanced solid tumors or NHL, and a cohort of patients with type 2 diabetes mellitus. Patients received three weekly intravenous infusions of copanlisib per 28-day cycle over the dose range 0.1-1.2 mg/kg. Plasma copanlisib levels were analyzed for pharmacokinetics. Biomarker analysis included PIK3CA, KRAS, BRAF, and PTEN mutational status and PTEN immunohistochemistry. Whole-body [(18)F]-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) was carried out at baseline and following the first dose to assess early pharmacodynamic effects. Plasma glucose and insulin levels were evaluated serially. RESULTS Fifty-seven patients received treatment. The MTD was 0.8 mg/kg copanlisib. The most frequent treatment-related adverse events were nausea and transient hyperglycemia. Copanlisib exposure was dose-proportional with no accumulation; peak exposure positively correlated with transient hyperglycemia post-infusion. Sixteen of 20 patients treated at the MTD had reduced (18)FDG-PET uptake; 7 (33%) had a reduction >25%. One patient achieved a complete response (CR; endometrial carcinoma exhibiting both PIK3CA and PTEN mutations and complete PTEN loss) and two had a partial response (PR; both metastatic breast cancer). Among the nine NHL patients, all six with follicular lymphoma (FL) responded (one CR and five PRs) and one patient with diffuse large B-cell lymphoma had a PR by investigator assessment; two patients with FL who achieved CR (per post hoc independent radiologic review) were on treatment >3 years. CONCLUSION Copanlisib, dosed intermittently on days 1, 8, and 15 of a 28-day cycle, was well tolerated and the MTD was determined to be 0.8 mg/kg. Copanlisib exhibited dose-proportional pharmacokinetics and promising anti-tumor activity, particularly in patients with NHL. CLINICALTRIALSGOV NCT00962611; https://clinicaltrials.gov/ct2/show/NCT00962611.
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Multicenter Study |
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Gu D, Wogensen L, Calcutt NA, Xia C, Zhu S, Merlie JP, Fox HS, Lindstrom J, Powell HC, Sarvetnick N. Myasthenia gravis-like syndrome induced by expression of interferon gamma in the neuromuscular junction. J Exp Med 1995; 181:547-57. [PMID: 7836911 PMCID: PMC2191877 DOI: 10.1084/jem.181.2.547] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Abnormal humoral responses toward motor end plate constituents in muscle induce myasthenia gravis (MG). To study the etiology of this disease, and whether it could be induced by host defense molecules, we examined the consequences of interferon (IFN) gamma production within the neuromuscular junction of transgenic mice. The transgenic mice exhibited gradually increasing muscular weakness, flaccid paralysis, and functional disruption of the neuromuscular junction that was reversed after administration of an inhibitor of acetylcholinesterase, features which are strikingly similar to human MG. Furthermore, histological examination revealed infiltration of mononuclear cells and autoantibody deposition at motor end plates. Immunoprecipitation analysis indicated that a previously unidentified 87-kD target antigen was recognized by sera from transgenic mice and also by sera from the majority of human MG patients studied. These results suggest that expression of IFN-gamma at motor end plates provokes an autoimmune humoral response, similar to human MG, thus linking the expression of this factor with development of this disease.
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Ma D, Xia C, Jiang J, Zhang J. First total synthesis of martinellic acid, a naturally occurring bradykinin receptor antagonist. Org Lett 2001; 3:2189-91. [PMID: 11440576 DOI: 10.1021/ol016043h] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The first total synthesis of martinellic acid, a naturally occurring bradykinin receptor antagonist, via a CuI-catalyzed coupling reaction of beta-amino ester 6 with 1,4-diiodobenzene and a guanylation reaction of secondary amine 3 under mild conditions as key steps, is described.
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Wang JH, Devalia JL, Xia C, Sapsford RJ, Davies RJ. Expression of RANTES by human bronchial epithelial cells in vitro and in vivo and the effect of corticosteroids. Am J Respir Cell Mol Biol 1996; 14:27-35. [PMID: 8534483 DOI: 10.1165/ajrcmb.14.1.8534483] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Recent studies have demonstrated that RANTES, a member of the CC chemokine family affecting monocytes, T cells, basophils, and eosinophils, is expressed by several cell types. To investigate whether human bronchial epithelial cells can also express this chemokine, we investigated human bronchial epithelial cells for their ability to synthesize RANTES, both in vitro and in vivo. Additionally, we investigated the effect of treatment for 4 mo with inhaled corticosteroids on the expression of RANTES in these cells in vivo. Human bronchial epithelial cells cultured from surgical tissue expressed the mRNA for RANTES and synthesized RANTES, as demonstrated by polymerase chain reaction and immunocytochemical staining and enzyme-linked immunosorbent assay, respectively. Incubation of the cultures with 50 ng/ml of tumor necrosis factor-alpha (TNF-alpha) significantly increased the release of RANTES into culture medium after 18 to 48 h of incubation, an effect that was abolished by treatment of the cultures with anti-TNF-alpha antibody. RANTES was also expressed in the bronchial epithelium in vivo, as indicated by positive immunocytochemical staining of bronchial biopsy tissues obtained from mild asthmatic patients before and after treatment with 500 micrograms of inhaled beclomethasone dipropionate (BDP) twice daily or matched placebo for 4 mo. Quantitation, by color image analysis, of the percentage of epithelium staining for RANTES showed that treatment with BDP decreased the expression of RANTES in the bronchial epithelium from 17.12% to 4.22% (P < 0.05). The numbers of EG2-staining cells in the epithelium were also reduced, from 790.1/mm2 to 203.3/mm2 (geometric mean; P < 0.01), after BDP treatment. These results suggest that human bronchial epithelial cells are capable of synthesizing RANTES and may therefore play an important role in the development of inflammation in allergic airways disease. Furthermore, corticosteroids may prevent airway inflammation by downregulating the expression of proinflammatory cytokines in the bronchial epithelium.
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Clinical Trial |
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Shimizu M, Higuchi K, Bennett B, Xia C, Tsuboyama T, Kasai S, Chiba T, Fujisawa H, Kogishi K, Kitado H, Kimoto M, Takeda N, Matsushita M, Okumura H, Serikawa T, Nakamura T, Johnson TE, Hosokawa M. Identification of peak bone mass QTL in a spontaneously osteoporotic mouse strain. Mamm Genome 1999; 10:81-7. [PMID: 9922384 DOI: 10.1007/s003359900949] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The whole genome scan for quantitative trait loci (QTLs) specifying peak bone mass was performed with the F2 intercrosses of SAMP6, an established murine model of senile osteoporosis, exhibiting a significantly lower peak bone mass, and SAMP2, exhibiting a higher peak bone mass. Cortical thickness index (CTI), a parameter of bone mass of femurs, was measured in 488 F2 progeny at 4 months of age, when the animals attained peak bone mass by microphotodensitometry. Genetic markers were typed at 90 loci spanning all chromosomes except the Y. By interval mapping of 246 male F2 mice, two loci were identified with significant linkage to peak bone mass, one on Chromosome (Chr) 11 and another on Chr 13, with a maximum lod score of 10.8 (22.2% of the total variance) and 5.8 (10.0%), respectively. Another locus on the X Chr was suggestive of a QTL associated oppositely with a low peak bone mass to the SAMP2 allele. This association was consistent with the distribution of peak bone mass in the F1 and F2. These findings should be useful to elucidate the genetics of osteoporosis.
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Islami F, Chen W, Yu XQ, Lortet-Tieulent J, Zheng R, Flanders WD, Xia C, Thun MJ, Gapstur SM, Ezzati M, Jemal A. Cancer deaths and cases attributable to lifestyle factors and infections in China, 2013. Ann Oncol 2018; 28:2567-2574. [PMID: 28961829 DOI: 10.1093/annonc/mdx342] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background The burden of cancer in China is high, and it is expected to further increase. Information on cancers attributable to potentially modifiable risk factors is essential in planning preventive measures against cancer. We estimated the number and proportion of cancer deaths and cases attributable to ever-smoking, second-hand smoking, alcohol drinking, low fruit/vegetable intake, excess body weight, physical inactivity, and infections in China, using contemporary data from nationally representative surveys and cancer registries. Methods The number of cancer deaths and cases in 2013 were obtained from the National Central Cancer Registry of China and data on most exposures were obtained from the China National Nutrition and Health Survey 2002 or 2006 and Global Adult Tobacco Smoking 2010. We used a bootstrap simulation method to calculate the number and proportion of cancer deaths and cases attributable to risk factors and their corresponding 95% confidence intervals (CIs), allowing for uncertainty in data. Results Approximately 718 000 (95% CI 702 100-732 200) cancer deaths in men and 283 100 (278 800-288 800) cancer deaths in women were attributable to the studied risk factors, accounting for 52% of all cancer deaths in men and 35% in women. The numbers for incident cancer cases were 952 500 (95% CI 934 200-971 400) in men and 442 700 (437 200-447 900) in women, accounting for 47% of all incident cases in men and 28% in women. The greatest proportions of cancer deaths attributable to risk factors were for smoking (26%), HBV infection (12%), and low fruit/vegetable intake (7%) in men and HBV infection (7%), low fruit/vegetable intake (6%), and second-hand smoking (5%) in women. Conclusions Effective public health interventions to eliminate or reduce exposure from these risk factors, notably tobacco control and vaccinations against carcinogenic infections, can have considerable impact on reducing the cancer burden in China.
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Journal Article |
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86 |
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Xia C, Bao Z, Yue C, Sanborn BM, Liu M. Phosphorylation and regulation of G-protein-activated phospholipase C-beta 3 by cGMP-dependent protein kinases. J Biol Chem 2001; 276:19770-7. [PMID: 11278298 DOI: 10.1074/jbc.m006266200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Among the drugs that are known to relax the vascular smooth muscle and regulate other cellular functions, beta-adrenergic agonists and nitric oxide-containing compounds are some of the most effective ones. The mechanisms of these drugs are thought to lower agonist-induced intracellular [Ca(2+)] by increasing intracellular cAMP and cGMP, activating their respective protein kinases. However, the physiological targets of cyclic nucleotide-dependent protein kinases are not clear. The molecular basis for the regulation of intracellular Ca(2+) by signaling pathways coupled to cyclic nucleotides is not well defined. G-protein-activated phospholipase C (PLC-beta) catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphates to generate diacylglycerol and inositol 1,4,5-triphosphate, leading to the activation of protein kinase C and the mobilization of intracellular Ca(2+). In this study, we shown that G-protein-activated PLC enzymes are the potential targets of cGMP-dependent protein kinases (PKG). PKG can directly phosphorylate PLC-beta2 and PLC-beta3 in vitro with purified proteins and in vivo with metabolic labeling. Phosphorylation of PLC-beta leads to the inhibition of G-protein-activated PLC-beta3 activity by 50-70% in COS-7 cell transfection assays. By using phosphopeptide mapping and site-directed mutagenesis, we further identified two key phosphorylation sites for the regulation of PLC-beta3 by PKG (Ser(26) and Ser(1105)). Mutation at these two sites (S26A and S1105A) of PLC-beta3 completely blocked the phosphorylation of PLC-beta3 protein catalyzed by PKG. Furthermore, mutation of these serine residues removed the inhibitory effect of PKG on the activation of the mutant PLC-beta3 proteins by G-protein subunits. Our results suggest a molecular mechanism for the regulation of G-protein-mediated intracellular [Ca(2+)] by the NO-cGMP-dependent signaling pathway.
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Xia C, Cheshire JK, Patel H, Woo P. Cross-talk between transcription factors NF-kappa B and C/EBP in the transcriptional regulation of genes. Int J Biochem Cell Biol 1997; 29:1525-39. [PMID: 9570146 DOI: 10.1016/s1357-2725(97)00083-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The study of the acute phase response has attracted substantial interest, not only for its medical implication, but also its provision as an excellent system with which to elucidate the molecular mechanisms involved in the modulation of gene expression. Our previous data suggest that the synergistic induction of the major acute phase reactant serum amyloid A2 (SAA2) expression by interleukin-1 (IL-1) and interleukin-6 (IL-6) is mediated by two families of transcription factors, namely NF-kappa B and C/EBP. To understand the molecular mechanisms of this synergy, we have undertaken a molecular dissection of the factors involved in the formation of the regulatory complex. Electrophoretic mobility shift analysis indicates that NF-kappa B p65 (RelA) and p50, but not p52 or c-Rel, bind specifically to the NF-kappa B site of the SAA2 promoter in response to IL-1 stimulation. In addition, C/EBP beta and C/EBP delta, but not C/EBP alpha, bind specifically to the C/EBP site of SAA2 in response to IL-6 stimulation. Transient co-transfection analysis indicates that co-operative association of NF-kappa B p65 with C/EBP beta and, in particular, with C/EBP delta, results in synergistic transcriptional activation of the SAA2 promoter. When incubated together, NF-kappa B p65 and C/EBP beta form a ternary complex by direct protein/protein interaction. Mutational analysis demonstrates that the C-terminus region of the Rel homology domain (RHD) and the C-terminus of the activation domain of p65 are important for its interaction with C/EBP beta. These results suggest the NF-kappa B and C/EBP may form a new complex of transcription factors that mediates the synergistic induction of SAA2 by IL-1 and IL-6.
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Xia C, Hu J, Ketterer B, Taylor JB. The organization of the human GSTP1-1 gene promoter and its response to retinoic acid and cellular redox status. Biochem J 1996; 313 ( Pt 1):155-61. [PMID: 8546677 PMCID: PMC1216876 DOI: 10.1042/bj3130155] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
High levels of expression of GSTP1-1 are associated with cell proliferation, embryogenesis and malignancy. Given the role of glutathione S-transferase (GST) in detoxication, it is possible that GSTP1-1 evolved specifically to protect proliferating cells and share regulatory mechanisms with other cellular genes which are involved in cell division and tumorigenesis. We have previously shown that the expression of GSTP1 is suppressed by retinoic acid (RA) in the presence of the retinoic acid receptor (RAR) as a result of decreased transcription from its promoter. Through deletion analysis, we show here that the RA-RAR-dependent repression is mediated by the region -73 to +8. Further mutation analysis of this region indicates that the DNA sequence required for RA-RAR-dependent repression co-localizes with a consensus activator protein-1 (AP1) site essential for the promoter activity. The degree of repression correlates with the residual activity of the AP1 site. There are two adjacent G/C boxes. The one immediately downstream from the AP1 site is not essential for the promoter activity, but mutation of the second, further downstream, impairs the promoter. On the other hand, mutation of either of these two G/C boxes has little effect on RA-RAR suppression. We also show that the expression of GSTP1 is regulated by the redox status of the cell. Using the chloramphenicol acetyltransferase assay system, we have demonstrated that treatment with H2O2 induced transcription from the promoter and that this effect can be blocked by pre-incubation with N-acetylcysteine (NAC). It was shown that the induction by H2O2 is mediated by trans-acting factor NF-kappa B (nuclear factor kappa B), via a putative NF-kappa B site, 'GGGACCCTCC', located from -96 to -86. Co-transfection with an NF-kappa B (p65) expression construct increased the promoter activity, an effect which could be blocked by co-transfection with an I kappa B (MAD-3) expression construct. Deletion of the NF-kappa B site abolished the effect of both H2O2 and co-transfection of NF-kappa B. Interestingly, NAC is also an inducer for GSTP1. The effect of NAC was shown to be mediated largely by the AP1 site, since mutation of this site abolished the induction by NAC.
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research-article |
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Moriyama T, Fujibayashi M, Fujiwara Y, Kaneko T, Xia C, Imai E, Kamada T, Ando A, Ueda N. Angiotensin II stimulates interleukin-6 release from cultured mouse mesangial cells. J Am Soc Nephrol 1995; 6:95-101. [PMID: 7579076 DOI: 10.1681/asn.v6195] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Interleukin-6 (IL-6) is a multifunctional cytokine exerting a wide variety of biologic responses, including cell proliferation. Recently, IL-6 has been known to play a role in the pathogenesis of mesangial proliferative glomerulonephritis. IL-6 is now recognized as an autocrine growth factor for glomerular mesangial cells, and various inflammatory mediators have been shown to promote IL-6 release from mesangial cells. However, little is known about the noninflammatory stimuli of IL-6 release from mesangial cells. In this study, it was hypothesized that angiotensin II (AngII) is one of the noninflammatory mediators of IL-6 release in mesangial cells, and the effects of AngII on IL-6 release and mRNA expression in cultured mouse mesangial cells (CMMC) were investigated. It was demonstrated that AngII (10(-7) M or higher) caused IL-6 release and mRNA accumulation in CMMC. IL-6 release was detected at 4 h and reached a plateau at 8 h after the addition of AngII, whereas IL-6 mRNA expression peaked at 4 h. The effects of AngII on IL-6 release and gene expression were completely blocked by the AngII receptor type 1 (AT1 receptor) antagonist CV-11974. AngII and IL-6 were both shown to stimulate DNA synthesis in CMMC, and the blockade of IL-6 signaling with anti-IL-6 receptor antibody abolished the enhanced DNA synthesis induced by AngII. These results raise a possibility that the growth-promoting effect of AngII on mesangial cells is at least partially mediated by IL-6 released from mesangial cells.
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Xia C, Ma W, Wang F, Liu M. Identification of a prostate-specific G-protein coupled receptor in prostate cancer. Oncogene 2001; 20:5903-7. [PMID: 11593396 DOI: 10.1038/sj.onc.1204803] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2001] [Revised: 06/26/2001] [Accepted: 07/05/2001] [Indexed: 11/09/2022]
Abstract
Membrane receptors coupled to heterotrimeric G-proteins play an essential role in the transmission of signals from the extracellular environment to the cytoplasm of the cell. A wide variety of external stimuli, including neurotransmitters, hormones, phospholipids, photons, odorants, taste ligands, and growth factors, can activate specific members of the G-protein coupled receptors (GPCRs). Besides essential functions in fully differentiated cells and tissues, GPCRs are also involved in embryogenesis, tissue regeneration, cell growth stimulation, and cell proliferation. In this study, we identified a novel prostate-specific G-protein coupled receptor that interacts with Galpha(12) in our yeast two-hybrid assays. The expression of the receptor protein is highly restricted to human prostate tissues using multiple-tissue Northern blot analysis, and tissue expression array. Furthermore, the expression of prostate-specific receptor is increased significantly in prostate tumors in comparison with the matched normal prostate tissues using PCR and Southern blot analysis, suggesting a potential role of this tissue-specific G-protein coupled receptor in prostate cancer development.
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Sun L, Zhang H, Wu L, Shu S, Xia C, Xu C, Zheng J. 1H-Nuclear magnetic resonance-based plasma metabolic profiling of dairy cows with clinical and subclinical ketosis. J Dairy Sci 2014; 97:1552-62. [DOI: 10.3168/jds.2013-6757] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 11/23/2013] [Indexed: 12/14/2022]
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Xia C, Ma W, Stafford LJ, Marcus S, Xiong WC, Liu M. Regulation of the p21-activated kinase (PAK) by a human Gbeta -like WD-repeat protein, hPIP1. Proc Natl Acad Sci U S A 2001; 98:6174-9. [PMID: 11371639 PMCID: PMC33441 DOI: 10.1073/pnas.101137298] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The family of p21-activated protein kinases (PAKs) is composed of serine-threonine kinases whose activity is regulated by the small guanosine triphosphatases (GTPases) Rac and Cdc42. In mammalian cells, PAKs have been implicated in the regulation of mitogen-activated protein cascades, cellular morphological and cytoskeletal changes, neurite outgrowth, and cell apoptosis. Although the ability of Cdc42 and Rac GTPases to activate PAK is well established, relatively little is known about the negative regulation of PAK or the identity of PAK cellular targets. Here, we describe the identification and characterization of a human PAK-interacting protein, hPIP1. hPIP1 contains G protein beta-like WD repeats and shares sequence homology with the essential fission yeast PAK regulator, Skb15, as well as the essential budding yeast protein, MAK11. Interaction of hPIP1 with PAK1 inhibits the Cdc42/Rac-stimulated kinase activity through the N-terminal regulatory domains of PAK1. Cotransfection of hPIP1 in mammalian cells inhibits PAK-mediated c-Jun N-terminal kinase and nuclear factor kappa B signaling pathways. Our results demonstrate that hPIP1 is a negative regulator of PAK and PAK signaling pathways.
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Research Support, U.S. Gov't, P.H.S. |
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Chen CF, Lang SY, Zuo PP, Yang N, Wang XQ, Xia C. Effects of D-galactose on the expression of hippocampal peripheral-type benzodiazepine receptor and spatial memory performances in rats. Psychoneuroendocrinology 2006; 31:805-11. [PMID: 16707226 DOI: 10.1016/j.psyneuen.2006.03.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Revised: 03/14/2006] [Accepted: 03/17/2006] [Indexed: 11/26/2022]
Abstract
The changes in spatial memory performances and the binding of hippocampal peripheral-type benzodiazepine receptor (PBR) induced by D-galactose (D-gal) were investigated in rats. The animals were randomly divided into two groups: saline-treated group and D-gal-induced aging group. All rats received 56 days of injection followed by 5 days of behavioral tests. The D-gal-induced aging rats presented significant impairment in water maze performance, compared with that in the saline-treated rats. A significant decrease in [3H]PK11195 binding in the synaptosomes from hippocampus in the D-gal-induced aging rats was observed, compared to that in the saline-treated rats. Meanwhile, the Scatchard analysis revealed that there was a decrease in Bmax, with no significant change in KD. Further analysis demonstrated that water maze performance was closely related to the PK11195 binding in all rats. These results suggest that D-gal decreased the density of PBR in hippocampal synaptosomes, which may be attributable to the progressive pathogenesis of aging in rats.
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Comparative Study |
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Ma W, Xia C, Ling P, Qiu M, Luo Y, Tan TH, Liu M. Leukocyte-specific adaptor protein Grap2 interacts with hematopoietic progenitor kinase 1 (HPK1) to activate JNK signaling pathway in T lymphocytes. Oncogene 2001; 20:1703-14. [PMID: 11313918 DOI: 10.1038/sj.onc.1204224] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2000] [Revised: 12/21/2000] [Accepted: 01/04/2001] [Indexed: 11/09/2022]
Abstract
Immune cell-specific adaptor proteins create various combinations of multiprotein complexes and integrate signals from cell surface receptors to the nucleus, modulating the specificity and selectivity of intracellular signal transduction. Grap2 is a newly identified adaptor protein specifically expressed in lymphoid tissues. This protein shares 40--50% sequence homology in the SH3 and the SH2 domain with Grb2 and Grap. However, the Grap2 protein has a unique 120-amino acid glutamine- and proline-rich domain between the SH2 and C-terminal SH3 domains. The expression of Grap2 is highly restricted to lymphoid organs and T lymphocytes. In order to understand the role of this specific adaptor protein in immune cell signaling and activation, we searched for the Grap2 interacting protein in T lymphocytes. We found that Grap2 interacted with the hematopoietic progenitor kinase 1 (HPK1) in vitro and in Jurkat T cells. The interaction was mediated by the carboxyl-terminal SH3 domain of Grap2 with the second proline-rich motif of HPK1. Coexpression of Grap2 with HPK1 not only increased the kinase activity of HPK1 in the cell, but also had an additive effect on HPK1 mediated JNK activation. Furthermore, over expression of Grap2 and HPK1 induced significant transcriptional activation of c-Jun in the JNK signaling pathway and IL-2 gene reporter activity in stimulated Jurkat T cells. Therefore, our data suggest that the hematopoietic specific proteins Grap2 and HPK1 form a signaling complex to mediate the c-Jun NH(2)-terminal kinase (JNK) signaling pathway in T cells.
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Xia C, Bao Z, Tabassam F, Ma W, Qiu M, Hua S, Liu M. GCIP, a novel human grap2 and cyclin D interacting protein, regulates E2F-mediated transcriptional activity. J Biol Chem 2000; 275:20942-8. [PMID: 10801854 DOI: 10.1074/jbc.m002598200] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulation of mammalian cell growth and proliferation is governed through receptor-mediated signaling networks that ultimately converge on the cell cycle machinery. Adaptor proteins play essential roles in the formation of intracellular signaling complexes, relaying extracellular signals from the plasma membrane to the nucleus of a cell. The leukocyte-specific adaptor protein Grap2 is a central linker protein in immune cell signaling and activation. Using Grap2 as bait protein, we identified a novel human protein, GCIP (Grap2 cyclin-D interacting protein). We found that GCIP bound to Grap2 in both yeast two-hybrid assays and in mammalian cells through binding to the COOH-terminal unique domain and SH3 domain (designated QC domain) of Grap2. GCIP also associated with cyclin D both in vitro and in vivo. The expression of GCIP was found in all human tissues examined with the highest level of expression in the heart, muscle, peripheral blood leukocytes, and brain. Furthermore, phosphorylation of retinoblastoma protein by cyclin D-dependent protein kinase was reduced and E2F1-mediated transcription activity was inhibited in cells transfected with GCIP. High level expression of GCIP in terminally differentiated tissues and the inhibition of E2F1 transcription activation suggest that GCIP could play an important role in controlling cell differentiation and proliferation.
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He J, Xia C, He Y, Pan D, Cao J, Sun Y, Zeng X. Proteomic responses to oxidative damage in meat from ducks exposed to heat stress. Food Chem 2019; 295:129-137. [PMID: 31174741 DOI: 10.1016/j.foodchem.2019.05.073] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 12/11/2022]
Abstract
Heat stress causes oxidative damage and quality reduction in poultry. Here, a tandem mass tag proteomic approach was applied to investigate the proteomic differences in duck meat from birds exposed to heat stress. Altogether 212 differential proteins were identified, including 178 down-regulated and 34 up-regulated proteins, compared to the control. Malondialdehyde and carbonyl content and cooking loss of the chest muscle significantly increased under heat stress. The proteomic analysis indicated that heat stress suppressed mitochondrial functions and respiratory chains, which might be responsible for the higher oxidation level. The results also revealed potential protective proteins involved in the defensive mechanisms against heat stress in duck muscles, such as sarcoplasmic/endoplasmic reticulum calcium ATPases, Mn-superoxide dismutase, heat shock protein family B member 7, methyltransferase like 21C, myosin-binding protein C, and carbonic anhydrase 3. These results provide potential targets for the research and identification of oxidative meat products due to heat stress.
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Journal Article |
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Ji Y, Yang K, Peng S, Chen S, Xiang B, Xu Z, Li Y, Wang Q, Wang C, Xia C, Li L, Liu X, Lu G, Yang G, Wu H. Kaposiform haemangioendothelioma: clinical features, complications and risk factors for Kasabach-Merritt phenomenon. Br J Dermatol 2018; 179:457-463. [PMID: 29603128 PMCID: PMC11032113 DOI: 10.1111/bjd.16601] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND Few studies have reported the clinical features, complications and predictors of Kasabach-Merritt phenomenon (KMP) associated with Kaposiform haemangioendothelioma (KHE). OBJECTIVES To determine the clinical characteristics present at diagnosis and to identify features that may aid clinicians in managing KHE. METHODS We conducted a cohort study of 146 patients diagnosed with KHE. RESULTS KHE precursors or lesions were present at birth in 52·1% of patients. In 91·8% of patients, lesions developed within the first year of life. The median age at diagnosis of KHE was 2·3 months (interquartile range 1·0-6·0). The extremities were the dominant location, representing 50·7% of all KHEs. Among KHEs in the cohort, 63·0% were mixed lesions (cutaneous lesions with deep infiltration). Approximately 70% of patients showed KMP. A KHE diagnosis was delayed by ≥ 1 month in 65·7% of patients with KMP. Patients with KMP were more likely to have major complications than patients without KMP (P = 0·023). Young age (< 6 months), trunk location, large lesion size (> 5·0 cm) and mixed lesion type were associated with KMP in a univariate analysis. In the multivariate analysis, only age [odds ratio (OR) 11·9, 95% confidence interval (CI) 4·07-34·8; P < 0·001], large lesion size (OR 5·08, 95% CI 2·24-11·5; P < 0·001) and mixed lesion type (OR 2·96, 95% CI 1·23-7·13; P = 0·016) were associated with KMP. CONCLUSIONS Most KHEs appeared before 12 months of age. KHEs are associated with various major complications, which can occur in combination and develop early in the disease process. Young age, large lesion size and mixed lesion type are important predictors of KMP.
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Video-Audio Media |
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Li Y, Zhou D, Xia C, Wang PG, Levery SB. Sensitive quantitation of isoglobotriaosylceramide in the presence of isobaric components using electrospray ionization-ion trap mass spectrometry. Glycobiology 2007; 18:166-76. [DOI: 10.1093/glycob/cwm127] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Baelum V, Wen-Min L, Dahlen G, Fejerskov O, Xia C. Six-year progression of destructive periodontal disease in 2 subgroups of elderly Chinese. J Periodontol 1993; 64:891-9. [PMID: 8229626 DOI: 10.1902/jop.1993.64.9.891] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Two groups of elderly chinese were selected from a large epidemiological sample on the basis of a low ("best" group) or a high ("worst" group) number of sites with attachment loss levels > or = 6 mm and/or pocket depth > or = 4 mm and at least 16 teeth present. Six years later the patients were clinically reexamined and the subgingival microflora was assessed. This paper presents the clinical characteristics of destructive periodontal disease progression among the two subgroups. The "best" group lost an average of 1.8 teeth, contrasting the average loss of 5.3 teeth among the "worst" group. Virtually all teeth lost among the "worst" group had a baseline attachment loss level > or = 4 mm, in contrast to 48% among the "best" group. While dental caries could be identified as a cause of tooth loss in both groups, the excess tooth loss among the "worst" group seems attributable to periodontal destruction. The average of 1.21 mm attachment/site lost among the "best" group was not statistically significantly different from the 1.36 mm/site lost among the "worst" group during the 6 years. Individual mean losses of attachment ranged from a gain of 0.03 mm to a loss of 3.19 mm. An attachment loss > or = 2 mm at a site was highly positively associated with a high initial attachment loss level (> or = 4 mm) at that site among the "best" group, whereas a highly negative association was seen among the "worst" group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Review |
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Meyer DJ, Xia C, Coles B, Chen H, Reinemer P, Huber R, Ketterer B. Unusual reactivity of Tyr-7 of GSH transferase P1-1. Biochem J 1993; 293 ( Pt 2):351-6. [PMID: 8343114 PMCID: PMC1134366 DOI: 10.1042/bj2930351] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Reaction of human GSH transferase P1-1 (GSTP1-1) with diethylpyrocarbonate (DEPC) at pH 7.0 and 4 degrees C resulted in covalent modification of an equivalent of one histidine and one tyrosine residue per subunit, with loss of activity. Sequence analysis showed that His-71 and Tyr-7 were modified. Reference to the three-dimensional structure of GSTP1-1 [Reinemer, Dirr, Ladenstein, Huber, Lo Bello, Frederici and Parker (1992) J. Mol. Biol. 227, 214-226] shows that the modification of Tyr-7 is most likely to affect enzyme activity. Kinetic analysis of the DEPC modification of Tyr-7 in GSTP1-1 gave a k2 approx. 150 times that of a peptide comprising residues 1-11 of GSTP1-1. The reaction of Tyr-7 of GSTP1-1 with DEPC was poorly inhibited by 1 mM GSH (14%) or 10 microM S-hexylglutathione (18%). DEPC treatment of the enzyme altered the absorbance at 290 nm in second-derivative spectra, suggesting that a significant amount of tyrosinate ion occurs in the enzyme. GSH, however, did not significantly alter the A290. The data provide the first evidence of unusual chemical reactivity of Tyr-7 and are consistent with its proposed role as a proton acceptor during catalysis.
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research-article |
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Xia C, He Y, Cheng S, He J, Pan D, Cao J, Sun Y. Free fatty acids responsible for characteristic aroma in various sauced-ducks. Food Chem 2020; 343:128493. [PMID: 33158671 DOI: 10.1016/j.foodchem.2020.128493] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/27/2020] [Accepted: 10/25/2020] [Indexed: 11/26/2022]
Abstract
To investigate the effects of various duck sources on the lipid oxidation and aroma flavor of sauced-ducks, Mallard (ML), Sheldrake (SD), Muscovy (MC), and Cherry-Valley (CV) ducks were used in sauced-duck processing. The results showed significantly different thiobarbituric acid reactive substances (TBARS) values of the four samples (SD > CV > ML > MC, p < 0.05), while the contents of unsaturated fatty acids (UFAs) were ML > SD/CV > MC (p < 0.05). Altogether, 105 volatile flavor compounds were detected in sauced-ducks, including acids, alcohols, aldehydes, ketones, esters, hydrocarbons, furans, nitrogen compounds, and others. The volatile compounds were observed differentially composed in the four products, and nineteen potential characteristic biomarkers were explored. The correlation analysis indicated that the characteristic aroma flavor of sauced-ducks were significantly associated with specific free fatty acids. These information are useful for learning aroma formation and meat selection and identification in duck products.
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Journal Article |
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