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Min C, Eddy SF, Sherr DH, Sonenshein GE. NF-kappaB and epithelial to mesenchymal transition of cancer. J Cell Biochem 2008; 104:733-44. [PMID: 18253935 DOI: 10.1002/jcb.21695] [Citation(s) in RCA: 336] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During progression of an in situ to an invasive cancer, epithelial cells lose expression of proteins that promote cell-cell contact, and acquire mesenchymal markers, which promote cell migration and invasion. These events bear extensive similarities to the process of epithelial to mesenchymal transition (EMT), which has been recognized for several decades as critical feature of embryogenesis. The NF-kappaB family of transcription factors plays pivotal roles in both promoting and maintaining an invasive phenotype. After briefly describing the NF-kappaB family and its role in cancer, in this review we will first describe studies elucidating the functions of NF-kappaB in transcription of master regulator genes that repress an epithelial phenotype. In the second half, we discuss the roles of NF-kappaB in control of mesenchymal genes critical for promoting and maintaining an invasive phenotype. Overall, NF-kappaB is identified as a key target in prevention and in the treatment of invasive carcinomas.
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Review |
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336 |
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Alonso MJ, Gupta RK, Min C, Siber GR, Langer R. Biodegradable microspheres as controlled-release tetanus toxoid delivery systems. Vaccine 1994; 12:299-306. [PMID: 8178550 DOI: 10.1016/0264-410x(94)90092-2] [Citation(s) in RCA: 217] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Purified tetanus toxoid, a high-molecular-weight protein, was entrapped within poly(L-lactic acid) (PLA) and poly(D,L-lactic/glycolic acid) (PLGA) microspheres prepared by either a solvent extraction or a solvent evaporation method carried out in a multiple emulsion system (water-in-oil-in-water). The physical integrity and antigenicity of the protein treated under different processing conditions were investigated. A reduction of antigenicity that was related to the percentage of aggregated protein was noticed under some experimental conditions. This partial loss of antigenicity was associated with the lyophilization process and affected by the nature of the organic solvent. All types of microspheres prepared with different molecular weight PLA and PLGA displayed a high protein-loading efficiency (> 80%) but their size was strongly influenced by polymer molecular weight (3000 versus 100,000). Protein release pattern was influenced by both polymer molecular weight and composition (PLA versus PLGA). A constant release pattern after an induction period of 10 days was observed for microspheres composed of high-molecular-weight polymers (PLA and PLGA). The release rate was lower from PLA microspheres than from PLGA microspheres. In contrast, a continuously increasing release rate preceded by a burst was observed for low-molecular-weight (3000) PLGA microspheres. Microencapsulated tetanus toxoid was significantly more immunogenic in mice than fluid toxoid as determined by IgG anti-tetanus antibody levels and neutralizing antibodies. However, the magnitude and duration of the antibody response did not differ significantly from a similar dose of aluminium phosphate-adsorbed toxoid. We conclude that microencapsulated tetanus toxoid shows significant adjuvant activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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217 |
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Mager S, Min C, Henry DJ, Chavkin C, Hoffman BJ, Davidson N, Lester HA. Conducting states of a mammalian serotonin transporter. Neuron 1994; 12:845-59. [PMID: 8161456 DOI: 10.1016/0896-6273(94)90337-9] [Citation(s) in RCA: 202] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have studied permeation at a cloned rat 5-HT transporter expressed in Xenopus oocytes. [3H]5-HT uptake and [125I]RTI-55 binding yield a turnover rate of approximately 1/s that does not depend on membrane potential. However, in voltage-clamp experiments, three distinct currents results from 5-HT transporter expression. First, a steady-state, voltage-dependent transport-associated current is induced by 5-HT application. Second, a transient inward current is activated by voltage jumps to high negative potentials in the absence of 5-HT and is blocked by 5-HT itself. Third, a small leakage current is observed in the absence of 5-HT. All the observed currents are blocked by inhibitors of 5-HT uptake but are differentially affected by Na+, Li+, K+, Ba2+, Cs+, Cl-, and amiloride. The conducting states of the 5-HT transporter may reflect the existence of a permeation pathway similar to that of ionic channels.
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202 |
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Scott KL, Nogueira C, Heffernan TP, van Doorn R, Dhakal S, Hanna JA, Min C, Jaskelioff M, Xiao Y, Wu CJ, Cameron LA, Perry SR, Zeid R, Feinberg T, Kim M, Woude GV, Granter SR, Bosenberg M, Chu GC, DePinho RA, Rimm DL, Chin L. Proinvasion metastasis drivers in early-stage melanoma are oncogenes. Cancer Cell 2011; 20:92-103. [PMID: 21741599 PMCID: PMC3176328 DOI: 10.1016/j.ccr.2011.05.025] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 04/28/2011] [Accepted: 05/28/2011] [Indexed: 12/20/2022]
Abstract
Clinical and genomic evidence suggests that the metastatic potential of a primary tumor may be dictated by prometastatic events that have additional oncogenic capability. To test this "deterministic" hypothesis, we adopted a comparative oncogenomics-guided function-based strategy involving: (1) comparison of global transcriptomes of two genetically engineered mouse models with contrasting metastatic potential, (2) genomic and transcriptomic profiles of human melanoma, (3) functional genetic screen for enhancers of cell invasion, and (4) evidence of expression selection in human melanoma tissues. This integrated effort identified six genes that are potently proinvasive and oncogenic. Furthermore, we show that one such gene, ACP5, confers spontaneous metastasis in vivo, engages a key pathway governing metastasis, and is prognostic in human primary melanomas.
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Research Support, N.I.H., Extramural |
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117 |
5
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Min C, Kirsch KH, Zhao Y, Jeay S, Palamakumbura AH, Trackman PC, Sonenshein GE. The Tumor Suppressor Activity of the Lysyl Oxidase Propeptide Reverses the Invasive Phenotype of Her-2/neu–Driven Breast Cancer. Cancer Res 2007; 67:1105-12. [PMID: 17283144 DOI: 10.1158/0008-5472.can-06-3867] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Expression of the lysyl oxidase gene (LOX) was found to inhibit the transforming activity of the ras oncogene in NIH 3T3 fibroblasts and was hence named the ras recision gene (rrg). Lysyl oxidase (LOX) is synthesized and secreted as a 50-kDa inactive proenzyme (Pro-LOX), which is processed by proteolytic cleavage to a functional 32-kDa enzyme and an 18-kDa propeptide (LOX-PP). Recently, the ras recision activity of the LOX gene in NIH 3T3 cells was mapped to its propeptide region. Here, we show for the first time that LOX-PP inhibits transformation of breast cancer cells driven by Her-2/neu, an upstream activator of Ras. LOX-PP expression in Her-2/neu-driven breast cancer cells in culture suppressed Akt, extracellular signal-regulated kinase, and nuclear factor-kappaB activation. Her-2/neu-induced epithelial to mesenchymal transition was reverted by LOX-PP, as judged by reduced levels of Snail and vimentin; up-regulation of E-cadherin, gamma-catenin, and estrogen receptor alpha; and decreased ability to migrate or to form branching colonies in Matrigel. Furthermore, LOX-PP inhibited Her-2/neu tumor formation in a nude mouse xenograft model. Thus, LOX-PP inhibits signaling cascades induced by Her-2/neu that promote a more invasive phenotype and may provide a novel avenue for treatment of Her-2/neu-driven breast carcinomas.
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Haddad JG, Min C, Mendelsohn M, Slatopolsky E, Hahn TJ. Competitive protein-binding radioassay of 24,25-dihydroxyvitamin D in sera from normal and anephric subjects. Arch Biochem Biophys 1977; 182:390-5. [PMID: 900941 DOI: 10.1016/0003-9861(77)90519-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Comparative Study |
48 |
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Wu M, Min C, Wang X, Yu Z, Kirsch KH, Trackman PC, Sonenshein GE. Repression of BCL2 by the tumor suppressor activity of the lysyl oxidase propeptide inhibits transformed phenotype of lung and pancreatic cancer cells. Cancer Res 2007; 67:6278-85. [PMID: 17616686 DOI: 10.1158/0008-5472.can-07-0776] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The gene encoding lysyl oxidase (LOX) was identified as the ras recision gene (rrg), with the ability to revert Ras-mediated transformation of NIH 3T3 fibroblasts. Mutations in RAS genes have been found in approximately 25% of lung cancers and in 85% of pancreatic cancers. In microarray analysis, these cancers were found to display reduced LOX gene expression. Thus, the ability of the LOX gene to repress the transformed phenotype of these cancer cells was tested. LOX is synthesized as a 50-kDa secreted precursor Pro-LOX that is processed to the 32-kDa active enzyme (LOX) and to an 18-kDa propeptide (LOX-PP). Recently, we mapped the rrg activity of Pro-LOX to the LOX-PP in Ras-transformed NIH 3T3 cells. Ectopic Pro-LOX and LOX-PP expression in H1299 lung cancer cells inhibited growth in soft agar and invasive colony formation in Matrigel and reduced activation of extracellular signal-regulated kinase (ERK) and Akt, with LOX-PP showing substantially higher activity. Similarly, LOX-PP expression in PANC-1 pancreatic cancer cells effectively reduced ERK and Akt activity and inhibited growth in soft agar and ability of these cells to migrate. Nuclear Factor-kappaB (NF-kappaB) and its target gene BCL2, which are overexpressed in 70% to 75% of pancreatic cancers, have recently been implicated in invasive phenotype. LOX-PP substantially reduced NF-kappaB and Bcl-2 levels. Reintroduction of Bcl-2 into PANC-1 or H1299 cells expressing LOX-PP restored the transformed phenotype, suggesting that Bcl-2 is an essential target. Thus, LOX-PP potently inhibits invasive phenotype of lung and pancreatic cancer cells, suggesting potential therapeutic applications in treatment of these cancers.
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Research Support, U.S. Gov't, Non-P.H.S. |
18 |
76 |
8
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Min C, Kang E, Yu SH, Shinn SH, Kim YS. Advanced glycation end products induce apoptosis and procoagulant activity in cultured human umbilical vein endothelial cells. Diabetes Res Clin Pract 1999; 46:197-202. [PMID: 10624785 DOI: 10.1016/s0168-8227(99)00094-7] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Hyperglycemia and the late products of non-enzymatic glycosylation, called advanced glycation end products (AGEs), play an important role in the development of microvascular complications in diabetes mellitus. Previous studies have reported that a high glucose environment triggered apoptotic changes in human umbilical vein endothelial cells (HUVECs). Therefore, we investigated whether AGEs contribute to the development of apoptosis and prothrombotic activity in HUVECs. After incubation of HUVECs with 0.2, 2.2, 22, 220 and 2200 nM of AGE-bovine serum albumin (BSA) from 6 to 48 h, we assayed the degree of apoptosis and procoagulant activity (PCA). There were no significant differences between HUVECs cultured for 48 h with 0.2, 2.2 or 22 nM of AGE-BSA and in controls in the proportion of apoptotic cells (3.5 +/- 0.8%, 3.9 +/- 1.5% and 5.2 +/- 1.1% vs. 2.5 +/- 0.6%). However, the proportion of apoptotic cells increased significantly to 36.7 +/- 9.8% in 220 nM of AGE-BSA, and 72.3 +/- 10.2% in 2200 nM of AGE-BSA (P < 0.001). PCA levels were 142 +/- 10 s after 6 h of exposure to 22 nM (P < 0.01), 131 +/- 5 s after 6 h of exposure to 220 nM (P < 0.001), and 106 +/- 4 s after 6 h of exposure to 2200 nM of AGE-BSA (P < 0.001). These values show that PCA was shortened significantly from the basal value of 161 +/- 6 s, and remained below the basal level until the end of the study. The amount of tissue factor was also significantly increased in 22 and 220 nM of AGE-BSA compared to the controls. In conclusion, this study showed that AGEs could induce apoptosis and increase procoagulant activity in cultured HUVECs. We suggest that AGEs can contribute to the development of microvascular complications through cell death of HUVECs and functional changes of the blood vessels.
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Issadore D, Park YI, Shao H, Min C, Lee K, Liong M, Weissleder R, Lee H. Magnetic sensing technology for molecular analyses. LAB ON A CHIP 2014; 14:2385-97. [PMID: 24887807 PMCID: PMC4098149 DOI: 10.1039/c4lc00314d] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Magnetic biosensors, based on nanomaterials and miniature electronics, have emerged as a powerful diagnostic platform. Benefiting from the inherently negligible magnetic background of biological objects, magnetic detection is highly selective even in complex biological media. The sensing thus requires minimal sample purification and yet achieves a high signal-to-background contrast. Moreover, magnetic sensors are also well-suited for miniaturization to match the size of biological targets, which enables sensitive detection of rare cells and small amounts of molecular markers. We herein summarize recent advances in magnetic sensing technologies, with an emphasis on clinical applications in point-of-care settings. Key components of sensors, including magnetic nanomaterials, labeling strategies and magnetometry, are reviewed.
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Research Support, N.I.H., Extramural |
11 |
58 |
10
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Min C, Yu Z, Kirsch KH, Zhao Y, Vora SR, Trackman PC, Spicer DB, Rosenberg L, Palmer JR, Sonenshein GE. A loss-of-function polymorphism in the propeptide domain of the LOX gene and breast cancer. Cancer Res 2009; 69:6685-93. [PMID: 19654310 PMCID: PMC2729564 DOI: 10.1158/0008-5472.can-08-4818] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The lysyl oxidase (LOX) gene reverted Ras transformation of NIH 3T3 fibroblasts and tumor formation by gastric cancer cells, which frequently carry mutant RAS genes. The secreted lysyl oxidase proenzyme is processed to a propeptide (LOX-PP) and a functional enzyme (LOX). Unexpectedly, the tumor suppressor activity mapped to the LOX-PP domain, which inhibited tumor formation and the invasive phenotype of NF639 breast cancer cells driven by human epidermal growth factor receptor-2/neu, which signals via Ras. A single-nucleotide polymorphism, G473A (rs1800449), resulting in an Arg158Gln substitution in a highly conserved region within LOX-PP, occurs with an average 473A allele carrier frequency of 24.6% in the HapMap database, but was present in many breast cancer cell lines examined. Here, we show that the Arg-to-Gln substitution profoundly impairs the ability of LOX-PP to inhibit the invasive phenotype and tumor formation of NF639 cells in a xenograft model. LOX-PP Gln displayed attenuated ability to oppose the effects of LOX, which promoted a more invasive phenotype. In a case-control study of African American women, a potential association of the Gln-encoding A allele was seen with increased risk of estrogen receptor (ER)-alpha-negative invasive breast cancer in African American women. Consistently, LOX gene expression was higher in ER-negative versus ER-positive primary breast cancers, and LOX-PP Gln was unable to inhibit invasion by ER-negative cell lines. Thus, these findings identify for the first time genetic polymorphism as a mechanism of impaired tumor suppressor function of LOX-PP and suggest that it may play an etiologic role in ER-negative breast cancer.
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Research Support, N.I.H., Extramural |
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57 |
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Qiao ZS, Min CY, Hua QX, Weiss MA, Feng YM. In vitro refolding of human proinsulin. Kinetic intermediates, putative disulfide-forming pathway folding initiation site, and potential role of C-peptide in folding process. J Biol Chem 2003; 278:17800-9. [PMID: 12624089 DOI: 10.1074/jbc.m300906200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human insulin is a double-chain peptide that is synthesized in vivo as a single-chain human proinsulin (HPI). We have investigated the disulfide-forming pathway of a single-chain porcine insulin precursor (PIP). Here we further studied the folding pathway of HPI in vitro. While the oxidized refolding process of HPI was quenched, four obvious intermediates (namely P1, P2, P3, and P4, respectively) with three disulfide bridges were isolated and characterized. Contrary to the folding pathway of PIP, no intermediates with one- or two-disulfide bonds could be captured under different refolding conditions. CD analysis showed that P1, P2, and P3 retained partially structural conformations, whereas P4 contained little secondary structure. Based on the time-dependent distribution, disulfide pair analysis, and disulfide-reshuffling process of the intermediates, we have proposed that the folding pathway of HPI is significantly different from that of PIP. These differences reveal that the C-peptide not only facilitates the folding of HPI but also governs its kinetic folding pathway of HPI. Detailed analysis of the molecular folding process reveals that there are some similar folding mechanisms between PIP and HPI. These similarities imply that the initiation site for the folding of PIP/HPI may reside in the central alpha-helix of the B-chain. The formation of disulfide A20-B19 may guide the transfer of the folding information from the B-chain template to the unstructured A-chain. Furthermore, the implications of this in vitro refolding study on the in vivo folding process of HPI have been discussed.
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Zhao Y, Min C, Vora SR, Trackman PC, Sonenshein GE, Kirsch KH. The lysyl oxidase pro-peptide attenuates fibronectin-mediated activation of focal adhesion kinase and p130Cas in breast cancer cells. J Biol Chem 2008; 284:1385-93. [PMID: 19029090 DOI: 10.1074/jbc.m802612200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The lysyl oxidase (LOX) gene encodes an enzyme (LOX) critical for extracellular matrix maturation. The LOX gene has also been shown to inhibit the transforming activity of Ras oncogene signaling. In particular, the pro-peptide domain (LOX-PP) released from the secreted precursor protein (Pro-LOX) was found to inhibit the transformed phenotype of breast, lung, and pancreatic cancer cells. However, the mechanisms of action of LOX-PP remained to be determined. Here, the ability of LOX-PP to attenuate the integrin signaling pathway, which leads to phosphorylation of focal adhesion kinase (FAK), and the activation of its downstream target p130Cas, was determined. In NF639 breast cancer cells driven by Her-2/neu, which signals via Ras, ectopic Pro-LOX and LOX-PP expression inhibited fibronectin-stimulated protein tyrosine phosphorylation. Importantly, phosphorylation of FAK on Tyr-397 and Tyr-576, and p130Cas were substantially reduced. The amount of endogenous p130Cas in the Triton X-100-insoluble protein fraction, and fibronectin-activated haptotaxis were decreased. Interestingly, expression of mature LOX enzyme enhanced fibronectin-stimulated integrin signaling. Of note, treatment with recombinant LOX-PP selectively reduced fibronectin-mediated haptotaxis of NF639, MDA-MB-231, and Hs578T breast cancer cells. Thus, evidence is provided that one mechanism of action of LOX-PP tumor suppression is to block fibronectin-stimulated signaling and cell migration.
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Research Support, U.S. Gov't, Non-P.H.S. |
17 |
55 |
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Roessner CA, Spencer JB, Stolowich NJ, Wang J, Nayar GP, Santander PJ, Pichon C, Min C, Holderman MT, Scott AI. Genetically engineered synthesis of precorrin-6x and the complete corrinoid, hydrogenobyrinic acid, an advanced precursor of vitamin B12. CHEMISTRY & BIOLOGY 1994; 1:119-24. [PMID: 9383380 DOI: 10.1016/1074-5521(94)90050-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Genetically engineered synthesis, in which the gene products, cofactors, and substrates of a complete pathway are combined in vitro in a single flask to give the target, can be a viable alternative to conventional chemical construction of molecules of complex structure and stereochemistry. We chose to attempt to synthesize the metal-free corrinoid hydrogenobyrinic acid, an advanced precursor of vitamin B12. RESULTS Cloning and overexpression of the genes necessary for the S-adenosyl methionine dependent conversion of 5-aminolevulinic acid (ALA) to precorrin-3 and those required for the synthesis of hydrogenobyrinic acid from precorrin-3 completed the repertoire of the 12 biosynthetic enzymes involved in corrin synthesis. Using these enzymes and the necessary cofactors, the multi-enzyme synthesis of hydrogenobyrinic acid from ALA can be achieved in 20% overall yield in a single reaction vessel, corresponding to an average of at least 90% conversion for each of the 17 steps involved. CONCLUSIONS By replacing the cell wall with glass, and by mixing the soluble biosynthetic enzymes and necessary cofactors, the major segment of the physiological synthesis of vitamin B12 has been accomplished. Since only those enzymes necessary for the synthesis of hydrogenobyrinic acid from ALA are supplied, none of the intermediates is deflected from the direct pathway. This results in an efficiency which in fact surpasses that of nature.
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Roessner CA, Min C, Hardin SH, Harris-Haller LW, McCollum JC, Scott AI. Sequence of the Candida albicans erg7 gene. Gene 1993; 127:149-50. [PMID: 8486282 DOI: 10.1016/0378-1119(93)90631-c] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The nucleotide sequence of the Candida albicans erg7 gene, which complements erg7 mutants of Saccharomyces cerevisiae and restores oxidosqualene cyclase activity, was determined. The gene encodes a 728-aa protein that displays homology with squalene-hopene cyclase, providing further evidence that erg7 is the gene encoding 2,3-oxidosqualene cyclase.
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Haddad JG, Min C, Walgate J, Hahn T. Competition by 24,25-dihydroxycholecalciferol in the competitive protein binding radioassay of 25-hydroxycalciferol. J Clin Endocrinol Metab 1976; 43:712-5. [PMID: 956355 DOI: 10.1210/jcem-43-3-712] [Citation(s) in RCA: 46] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
24,25-dihydroxycholecalciferol (24,25-(OH)2D3) is equipotent to 25-hydroxycholecalciferol in the displacement of 3H25-OHD3 from rat serum binding sites, and is extracted by the ethanol procedure recommended in non-chromatographic competitive protein binding radioassays for 25-OHD. Serum 24,25-(OH)2D content was measured following 24,25-(OH)2D3 isolation from lipid extracts by liquid-gel partition chromatography. Since normal serum 24,25-(OH)2D concentration is appreciable, non-chromatographic 25-OHD assays most probably overestimate serum 25-OHD levels as a result of their recognition of 24,25-(OH)2D3.
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Haddad JG, Walgate J, Min C, Hahn TJ. Vitamin D metabolite-binding proteins in human tissue. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 444:921-5. [PMID: 990280 DOI: 10.1016/0304-4165(76)90339-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Serum and post-microsomal supernatants of human lymphocyte, erythrocyte, skeletal muscle and parathyroid adenoma homogenates were examined for specific binding of 25-hydroxycholecalciferol (25-OHD3) and 1, 25-dihydroxycholecalciferol (1,25-(OH)2D3). Muscle, lymphocytes and parathyroid adenomata extracts contained a 6-S 25-OHD3-binding protein which was not found in erythrocyte extracts, and which was distinct from the smaller serum transport alpha-globulin. A cathodal, 1, 25-(OH)2D3-binding protein, which sedimented at 3-4 S was also detected in parathyroid tissue. These observations suggest the possibility of direct physiologic interaction between vitamin D metabolites and nucleated human tissues other than intestine and bone.
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Min C, Zheng M, Zhang X, Caron MG, Kim KM. Novel roles for β-arrestins in the regulation of pharmacological sequestration to predict agonist-induced desensitization of dopamine D3 receptors. Br J Pharmacol 2014; 170:1112-29. [PMID: 23992580 DOI: 10.1111/bph.12357] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 07/24/2013] [Accepted: 08/18/2013] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE In addition to typical GPCR kinase (GRK)-/β-arrestin-dependent internalization, dopamine D3 receptor employed an additional GRK-independent sequestration pathway. In this study, we investigated the molecular mechanism of this novel sequestration pathway. EXPERIMENTAL APPROACH Radioligand binding, flow cytometry and cell surface biotinylation assay were used to characterize trafficking properties of D2 and D3 receptors. Serine/threonine and N-linked glycosylation mutants of the D3 receptor were utilized to locate receptor regions involved in pharmacological sequestration and desensitization. Various point mutants of the D2 and D3 receptors, whose sequestration and desensitization properties were altered, were combined with knockdown cells of GRKs or β-arrestins to functionally correlate pharmacological sequestration and desensitization. KEY RESULTS The D3 receptor, but not the D2 receptor, showed characteristic trafficking behaviour in which receptors were shifted towards the more hydrophobic domains within the plasma membrane without translocation into other intracellular compartments. Among various amino acid residues tested, S145/S146, C147 and N12/19 were involved in pharmacological sequestration and receptor desensitization. Both pharmacological sequestration and desensitization of D3 receptor required β-arrestins, and functional relationship was observed between two processes when it was tested for D3 receptor variants and agonists. CONCLUSIONS AND IMPLICATIONS Pharmacological sequestration of D3 receptor accompanies movement of cell surface receptors into a more hydrophobic fraction within the plasma membrane and renders D3 receptor inaccessible to hydrophilic ligands. Pharmacological sequestration is correlated with desensitization of the D3 receptor in a Gβγ- and β-arrestin-dependent manner. This study provides new insights into molecular mechanism governing GPCR trafficking and desensitization.
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Research Support, Non-U.S. Gov't |
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Scott AI, Roessner CA, Stolowich NJ, Spencer JB, Min C, Ozaki SI. Biosynthesis of vitamin B12. Discovery of the enzymes for oxidative ring contraction and insertion of the fourth methyl group. FEBS Lett 1993; 331:105-8. [PMID: 8405386 DOI: 10.1016/0014-5793(93)80306-f] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In the vitamin B12 biosynthetic pathway the enzymes responsible for the conversion of precorrin-3 to precorrin-4 have been identified as the gene products of cobG and cobJ from Pseudomonas denitrificans. CobG catalyzes the oxidation of precorrin-3 to precorrin-3x (a hydroxy lactone) whereas CobJ is a SAM-dependent C-17 methyl transferase and is necessary for ring contraction. A mechanism for ring contraction is proposed.
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Roessner CA, Spencer JB, Ozaki S, Min C, Atshaves BP, Nayar P, Anousis N, Stolowich NJ, Holderman MT, Scott AI. Overexpression in Escherichia coli of 12 vitamin B12 biosynthetic enzymes. Protein Expr Purif 1995; 6:155-63. [PMID: 7606163 DOI: 10.1006/prep.1995.1019] [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: 01/26/2023]
Abstract
The first 12 enzymes involved in the biosynthesis of vitamin B12 from its five-carbon precursor, aminolevulinic acid, have been overexpressed in recombinant strains of Escherichia coli. The activity of each enzyme has been demonstrated by the biosynthesis of hydrogenobyrinic acid from aminolevulinic acid.
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Tharkar-Promod S, Johnson DP, Bennett SE, Dennis EM, Banowsky BG, Jones SS, Shearstone JR, Quayle SN, Min C, Jarpe M, Mosbruger T, Pomicter AD, Miles RR, Chen WY, Bhalla KN, Zweidler-McKay PA, Shrieve DC, Deininger MW, Chandrasekharan MB, Bhaskara S. HDAC1,2 inhibition and doxorubicin impair Mre11-dependent DNA repair and DISC to override BCR-ABL1-driven DSB repair in Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia. Leukemia 2018; 32:49-60. [PMID: 28579617 PMCID: PMC5716937 DOI: 10.1038/leu.2017.174] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/16/2017] [Accepted: 05/15/2017] [Indexed: 12/15/2022]
Abstract
Philadelphia chromosome-positive (Ph+) B-cell precursor acute lymphoblastic leukemia (ALL) expressing BCR-ABL1 oncoprotein is a major subclass of ALL with poor prognosis. BCR-ABL1-expressing leukemic cells are highly dependent on double-strand break (DSB) repair signals for their survival. Here we report that a first-in-class HDAC1,2 selective inhibitor and doxorubicin (a hyper-CVAD chemotherapy regimen component) impair DSB repair networks in Ph+ B-cell precursor ALL cells using common as well as distinct mechanisms. The HDAC1,2 inhibitor but not doxorubicin alters nucleosomal occupancy to impact chromatin structure, as revealed by MNase-Seq. Quantitative mass spectrometry of the chromatin proteome along with functional assays showed that the HDAC1,2 inhibitor and doxorubicin either alone or in combination impair the central hub of DNA repair, the Mre11-Rad51-DNA ligase 1 axis, involved in BCR-ABL1-specific DSB repair signaling in Ph+ B-cell precursor ALL cells. HDAC1,2 inhibitor and doxorubicin interfere with DISC (DNA damage-induced transcriptional silencing in cis)) or transcriptional silencing program in cis around DSB sites via chromatin remodeler-dependent and -independent mechanisms, respectively, to further impair DSB repair. HDAC1,2 inhibitor either alone or when combined with doxorubicin decreases leukemia burden in vivo in refractory Ph+ B-cell precursor ALL patient-derived xenograft mouse models. Overall, our novel mechanistic and preclinical studies together demonstrate that HDAC1,2 selective inhibition can overcome DSB repair 'addiction' and provide an effective therapeutic option for Ph+ B-cell precursor ALL.
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Research Support, N.I.H., Extramural |
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33 |
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Cho DI, Min C, Jung KS, Cheong SY, Zheng M, Cheong SJ, Oak MH, Cheong JH, Lee BK, Kim KM. The N-terminal region of the dopamine D2 receptor, a rhodopsin-like GPCR, regulates correct integration into the plasma membrane and endocytic routes. Br J Pharmacol 2012; 166:659-75. [PMID: 22117524 DOI: 10.1111/j.1476-5381.2011.01787.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Functional roles of the N-terminal region of rhodopsin-like GPCR family remain unclear. Using dopamine D(2) and D(3) receptors as a model system, we probed the roles of the N-terminal region in the signalling, intracellular trafficking of receptor proteins, and explored the critical factors that determine the functionality of the N-terminal region. EXPERIMENTAL APPROACH The N-terminal region of the D(2) receptor was gradually shortened or switched with that of the D(3) receptor or a non-specific sequence (FLAG), or potential N-terminal glycosylation sites were mutated. Effects of these manipulations on surface expression, internalization, post-endocytic behaviours and signalling were determined. KEY RESULTS Shortening the N-terminal region of the D(2) receptor enhanced receptor internalization and impaired surface expression and signalling; ligand binding, desensitization and down-regulation were not affected but their association with a particular microdomain, caveolae, was disrupted. Replacement of critical residues within the N-terminal region with the FLAG epitope failed to restore surface expression but partially restored the altered internalization and signalling. When the N-terminal regions were switched between D(2) and D(3) receptors, cell surface expression pattern of each receptor was switched. Mutations of potential N-terminal glycosylation sites inhibited surface expression but enhanced internalization of D(2) receptors. CONCLUSIONS AND IMPLICATIONS Shortening of N-terminus or mutation of glycosylation sites located within the N-terminus enhanced receptor internalization but impaired the surface expression of D(2) receptors. The N-terminal region of the D(2) receptor, in a sequence-specific manner, controls the receptor's conformation and integration into the plasma membrane, which determine its subcellular localization, intracellular trafficking and signalling properties.
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Research Support, Non-U.S. Gov't |
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Skoulidis F, Araujo HA, Do MT, Qian Y, Sun X, Cobo AG, Le JT, Montesion M, Palmer R, Jahchan N, Juan JM, Min C, Yu Y, Pan X, Arbour KC, Vokes N, Schmidt ST, Molkentine D, Owen DH, Memmott R, Patil PD, Marmarelis ME, Awad MM, Murray JC, Hellyer JA, Gainor JF, Dimou A, Bestvina CM, Shu CA, Riess JW, Blakely CM, Pecot CV, Mezquita L, Tabbó F, Scheffler M, Digumarthy S, Mooradian MJ, Sacher AG, Lau SCM, Saltos AN, Rotow J, Johnson RP, Liu C, Stewart T, Goldberg SB, Killam J, Walther Z, Schalper K, Davies KD, Woodcock MG, Anagnostou V, Marrone KA, Forde PM, Ricciuti B, Venkatraman D, Van Allen EM, Cummings AL, Goldman JW, Shaish H, Kier M, Katz S, Aggarwal C, Ni Y, Azok JT, Segal J, Ritterhouse L, Neal JW, Lacroix L, Elamin YY, Negrao MV, Le X, Lam VK, Lewis WE, Kemp HN, Carter B, Roth JA, Swisher S, Lee R, Zhou T, Poteete A, Kong Y, Takehara T, Paula AG, Parra Cuentas ER, Behrens C, Wistuba II, Zhang J, Blumenschein GR, Gay C, Byers LA, Gibbons DL, Tsao A, Lee JJ, Bivona TG, Camidge DR, Gray JE, Leighl NB, Levy B, Brahmer JR, Garassino MC, et alSkoulidis F, Araujo HA, Do MT, Qian Y, Sun X, Cobo AG, Le JT, Montesion M, Palmer R, Jahchan N, Juan JM, Min C, Yu Y, Pan X, Arbour KC, Vokes N, Schmidt ST, Molkentine D, Owen DH, Memmott R, Patil PD, Marmarelis ME, Awad MM, Murray JC, Hellyer JA, Gainor JF, Dimou A, Bestvina CM, Shu CA, Riess JW, Blakely CM, Pecot CV, Mezquita L, Tabbó F, Scheffler M, Digumarthy S, Mooradian MJ, Sacher AG, Lau SCM, Saltos AN, Rotow J, Johnson RP, Liu C, Stewart T, Goldberg SB, Killam J, Walther Z, Schalper K, Davies KD, Woodcock MG, Anagnostou V, Marrone KA, Forde PM, Ricciuti B, Venkatraman D, Van Allen EM, Cummings AL, Goldman JW, Shaish H, Kier M, Katz S, Aggarwal C, Ni Y, Azok JT, Segal J, Ritterhouse L, Neal JW, Lacroix L, Elamin YY, Negrao MV, Le X, Lam VK, Lewis WE, Kemp HN, Carter B, Roth JA, Swisher S, Lee R, Zhou T, Poteete A, Kong Y, Takehara T, Paula AG, Parra Cuentas ER, Behrens C, Wistuba II, Zhang J, Blumenschein GR, Gay C, Byers LA, Gibbons DL, Tsao A, Lee JJ, Bivona TG, Camidge DR, Gray JE, Leighl NB, Levy B, Brahmer JR, Garassino MC, Gandara DR, Garon EB, Rizvi NA, Scagliotti GV, Wolf J, Planchard D, Besse B, Herbst RS, Wakelee HA, Pennell NA, Shaw AT, Jänne PA, Carbone DP, Hellmann MD, Rudin CM, Albacker L, Mann H, Zhu Z, Lai Z, Stewart R, Peters S, Johnson ML, Wong KK, Huang A, Winslow MM, Rosen MJ, Winters IP, Papadimitrakopoulou VA, Cascone T, Jewsbury P, Heymach JV. CTLA4 blockade abrogates KEAP1/STK11-related resistance to PD-(L)1 inhibitors. Nature 2024; 635:462-471. [PMID: 39385035 PMCID: PMC11560846 DOI: 10.1038/s41586-024-07943-7] [Show More Authors] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 08/13/2024] [Indexed: 10/11/2024]
Abstract
For patients with advanced non-small-cell lung cancer (NSCLC), dual immune checkpoint blockade (ICB) with CTLA4 inhibitors and PD-1 or PD-L1 inhibitors (hereafter, PD-(L)1 inhibitors) is associated with higher rates of anti-tumour activity and immune-related toxicities, when compared with treatment with PD-(L)1 inhibitors alone. However, there are currently no validated biomarkers to identify which patients will benefit from dual ICB1,2. Here we show that patients with NSCLC who have mutations in the STK11 and/or KEAP1 tumour suppressor genes derived clinical benefit from dual ICB with the PD-L1 inhibitor durvalumab and the CTLA4 inhibitor tremelimumab, but not from durvalumab alone, when added to chemotherapy in the randomized phase III POSEIDON trial3. Unbiased genetic screens identified loss of both of these tumour suppressor genes as independent drivers of resistance to PD-(L)1 inhibition, and showed that loss of Keap1 was the strongest genomic predictor of dual ICB efficacy-a finding that was confirmed in several mouse models of Kras-driven NSCLC. In both mouse models and patients, KEAP1 and STK11 alterations were associated with an adverse tumour microenvironment, which was characterized by a preponderance of suppressive myeloid cells and the depletion of CD8+ cytotoxic T cells, but relative sparing of CD4+ effector subsets. Dual ICB potently engaged CD4+ effector cells and reprogrammed the tumour myeloid cell compartment towards inducible nitric oxide synthase (iNOS)-expressing tumoricidal phenotypes that-together with CD4+ and CD8+ T cells-contributed to anti-tumour efficacy. These data support the use of chemo-immunotherapy with dual ICB to mitigate resistance to PD-(L)1 inhibition in patients with NSCLC who have STK11 and/or KEAP1 alterations.
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MESH Headings
- Animals
- Female
- Humans
- Male
- Mice
- AMP-Activated Protein Kinase Kinases/genetics
- AMP-Activated Protein Kinase Kinases/metabolism
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- B7-H1 Antigen/metabolism
- B7-H1 Antigen/antagonists & inhibitors
- Carcinoma, Non-Small-Cell Lung/drug therapy
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/pathology
- Carcinoma, Non-Small-Cell Lung/immunology
- Clinical Trials, Phase III as Topic
- CTLA-4 Antigen/antagonists & inhibitors
- CTLA-4 Antigen/metabolism
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Immune Checkpoint Inhibitors/pharmacology
- Immune Checkpoint Inhibitors/therapeutic use
- Kelch-Like ECH-Associated Protein 1/genetics
- Kelch-Like ECH-Associated Protein 1/metabolism
- Lung Neoplasms/drug therapy
- Lung Neoplasms/genetics
- Lung Neoplasms/immunology
- Lung Neoplasms/pathology
- Mutation
- Nitric Oxide Synthase Type II/metabolism
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
- Tumor Microenvironment/drug effects
- Tumor Microenvironment/immunology
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
- Genes, Tumor Suppressor
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Cho DI, Zheng M, Min C, Kwon KJ, Shin CY, Choi HK, Kim KM. ARF6 and GASP-1 are post-endocytic sorting proteins selectively involved in the intracellular trafficking of dopamine D₂ receptors mediated by GRK and PKC in transfected cells. Br J Pharmacol 2013; 168:1355-74. [PMID: 23082996 PMCID: PMC3596642 DOI: 10.1111/bph.12025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 09/07/2012] [Accepted: 09/28/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE GPCRs undergo both homologous and heterologous regulatory processes in which receptor phosphorylation plays a critical role. The protein kinases responsible for each pathway are well established; however, other molecular details that characterize each pathway remain unclear. In this study, the molecular mechanisms that determine the differences in the functional roles and intracellular trafficking between homologous and PKC-mediated heterologous internalization pathways for the dopamine D₂ receptor were investigated. EXPERIMENTAL APPROACH All of the S/T residues located within the intracellular loops of D₂ receptor were mutated, and the residues responsible for GRK- and PKC-mediated internalization were determined in HEK-293 cells and SH-SY5Y cells. The functional role of receptor internalization and the cellular components that determine the post-endocytic fate of internalized D₂ receptors were investigated in the transfected cells. KEY RESULTS T134, T225/S228/S229 and S325 were involved in PKC-mediated D₂ receptor desensitization. S229 and adjacent S/T residues mediated the PKC-dependent internalization of D₂ receptors, which induced down-regulation and desensitization. S/T residues within the second intracellular loop and T225 were the major residues involved in GRK-mediated internalization of D₂ receptors, which induced receptor resensitization. ARF6 mediated the recycling of D₂ receptors internalized in response to agonist stimulation. In contrast, GASP-1 mediated the down-regulation of D₂ receptors internalized in a PKC-dependent manner. CONCLUSIONS AND IMPLICATIONS GRK- and PKC-mediated internalizations of D₂ receptors occur through different intracellular trafficking pathways and mediate distinct functional roles. Distinct S/T residues within D₂ receptors and different sorting proteins are involved in the dissimilar regulation of D₂ receptors by GRK2 and PKC.
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Comparative Study |
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Ohta K, Laborde N, Kajiya M, Shin J, Zhu T, Thondukolam A, Min C, Kamata N, Karimbux N, Stashenko P, Kawai T. Expression and possible immune-regulatory function of ghrelin in oral epithelium. J Dent Res 2011; 90:1286-92. [PMID: 21865591 PMCID: PMC3188459 DOI: 10.1177/0022034511420431] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 06/24/2011] [Accepted: 07/04/2011] [Indexed: 12/21/2022] Open
Abstract
Originally found in stomach mucosa, ghrelin is a peptide appetite hormone that has been implicated as an immuno-modulatory factor. Ghrelin has also been found in salivary glands and saliva; however, its expression patterns and biological properties in the oral cavity remain unclear. Therefore, we investigated the expression patterns of ghrelin in saliva, gingival crevicular fluid (GCF), and gingival tissue, as well as its in vitro effects on IL-8 production by TNF-α or LPS-stimulated oral epithelial cells. In the clinical samples obtained from 12 healthy volunteers, the concentration of ghrelin in GCF remarkably exceeded that detected in saliva. The expression of ghrelin mRNAs and growth hormone secretagogue (GHS) receptors could be detected in human oral epithelial cells. Immunohistochemical analysis revealed the expression of ghrelin in gingival epithelium, as well as in fibroblasts in the lamina propria. Ghrelin increased intracellular calcium mobilization and cAMP levels in oral epithelial cells, suggesting that ghrelin acts on epithelial cells to induce cell signaling. Furthermore, synthetic ghrelin inhibited the production of IL-8 from TNF-α or LPS-stimulated oral epithelial cells. These results indicate that ghrelin produced in the oral cavity appears to play a regulatory role in innate immune responses to inflammatory infection.
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Research Support, N.I.H., Extramural |
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27 |
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Abstract
Many of the most widely employed operations in molecular biology hinge upon the use of single-stranded DNA as a probe or template. Here we report a straightforward method by which to produce long single-stranded DNA molecules using the polymerase chain reaction (PCR) in combination with immobilized metal affinity chromatography (IMAC). We demonstrate that a tag consisting of six successive 6-histaminylpurine (H) residues (H6-tag) endows a DNA strand with selective retentivity onto a Ni2+-NTA-agarose chromatography matrix. The H6-tagged strand can then be eluted from the resin using 200 mM imidazole. Quantitative phosphorimaging analysis revealed that the PCR/IMAC procedure typically yields unmodified strands comprising >90% of the unbound DNA and H6-tagged strands comprising >95% of the bound fractions. DNA strands generated in this manner are shown to be excellent substrates for template-directed polymerization. The chemistry reported herein should facilitate a wide variety of operations in molecular biology, including automated DNA sequencing, hybridization screening of DNA libraries, assembly of gene cassettes, run-off transcription, site-directed mutagenesis and footprinting of protein-DNA complexes by template-directed interference footprinting.
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research-article |
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