276
|
Nardi V, Raz T, Cao X, Wu CJ, Stone RM, Cortes J, Deininger MWN, Church G, Zhu J, Daley GQ. Quantitative monitoring by polymerase colony assay of known mutations resistant to ABL kinase inhibitors. Oncogene 2007; 27:775-82. [PMID: 17684485 DOI: 10.1038/sj.onc.1210698] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Resistance to molecularly targeted chemotherapy, and the development of novel agents that are active against resistant forms of target proteins create the need for a sensitive and quantitative assay to monitor drug-resistant mutations in patients to guide treatment and assess response. Here, we describe an application of the polymerase colony (polony) method to identify and quantify known point mutations in the BCR-ABL oncogene in patients with chronic myelogenous leukemia who evolve resistance to ABL kinase inhibitors. The assay can detect mutations with a sensitivity of 10(-4), quantify the burden of drug-resistant cells, and simultaneously monitor the dynamics of several coexisting mutations. As a proof of concept, we analysed blood samples from three patients undergoing therapy with ABL kinase inhibitors and found that the patients' response to therapy correlated with our molecular monitoring. We were also able to detect mutations emerging in patients long before clinical relapse. Therefore, the polony assay could be applied to a larger patient sample to assess the utility of early mutation detection in patient-specific treatment decisions. Finally, this methodology could be a valuable research tool to shed light on the natural behavior of mutations pre-existing kinase inhibitors therapy and either disappearing over time or slowly taking over.
Collapse
|
277
|
Hirano N, Tsukamoto T, Mizoshita T, Koriyama C, Akiba S, Campos F, Carrasquilla G, Carrascal E, Cao X, Toyoda T, Ban H, Miki K, Tatematsu M. Down regulation of gastric and intestinal phenotypic expression in Epstein-Barr virus-associated stomach cancers. Histol Histopathol 2007; 22:641-9. [PMID: 17357094 DOI: 10.14670/hh-22.641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS We have previously demonstrated the importance of gastric and intestinal phenotypic expression for stomach carcinogenesis. In this study, we focused on Epstein-Barr virus (EBV)-associated stomach cancers, with special attention to Cdx2. METHODS AND RESULTS We evaluated the expression of gastric and intestinal phenotypic markers by immunohistochemistry in 35 EBV-positive [EBV (+)] and 75 EBV-negative [EBV (-)] stomach cancers in Colombia. The lesions were divided phenotypically into gastric (G), gastric-and-intestinal mixed (GI), intestinal (I), and null (N) phenotypes. In the EBV (+) cases, the lesions were divided phenotypically into 9 G (25.7%), 1 GI (2.9%), 3 I (8.6%), and 22 N (62.9%) types. Similarly, the EBV (-) lesions were also classified phenotypically as 15 G (20.0%), 19 GI (25.3%), 24 I (32.0%), and 17 N (22.7%) types. The proportion of N type EBV (+) lesions was higher than for their EBV (-) counterparts (P<0.0001). The expression of Cdx2 and MUC2 was also found to be significantly lower in EBV (+) than in EBV (-) stomach cancers (P=0.0001; P<0.0001). Cdx2 expression in the intestinal metaplastic glands present in non-neoplastic mucosa surrounding EBV (+) lesions was also significantly lower than in EBV (-) tumors (P=0.016) despite no evidence of EBV infection. CONCLUSIONS EBV (+) stomach cancers are characterized by low expression of intestinal phenotype markers, including Cdx2, and only occasional gastric phenotypic expression.
Collapse
|
278
|
Lufei C, Koh TH, Uchida T, Cao X. Pin1 is required for the Ser727 phosphorylation-dependent Stat3 activity. Oncogene 2007; 26:7656-64. [PMID: 17563747 DOI: 10.1038/sj.onc.1210567] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Signal transducer and activator of transcription 3 (Stat3) belongs to a family of latent cytoplasmic transcription factors important for cytokine signaling. Stat3 is constitutively activated in various tumors, and activated Stat3 itself also acts as an oncogene. Transcriptional activity of Stat3 is controlled by Tyr-phosphorylation, followed by dimerization and nuclear translocation. However, phosphorylation on Ser727 is indispensable for its maximal transcriptional activity with unclear mechanism. Here, we report that peptidyl-prolyl cis/trans isomerase 1 (Pin1), which specifically recognizes the pSer/Thr-Pro motifs on its target proteins, interacts with Stat3 upon cytokine/growth factor stimulation. Overexpression of Pin1 promotes Stat3 transcriptional activity and target gene expression, as well as recruitment of transcription coactivator, p300. These effects, however, were compromised in the Pin1-deficient cells, and were totally dependent on the Ser727 phosphorylation site. Finally, we showed that Pin1 enhances Stat3-mediated epithelial-mesenchymal transition in breast cancer cells induced by oncostatin M. Our data reveal a novel, Ser727 phosphorylation-dependent, post-translational regulation mechanism for Stat3.
Collapse
|
279
|
Lufei C, Koh TH, Uchida T, Cao X. Pin1 is required for the Ser727 phosphorylation-dependent Stat3 activity. Oncogene 2007. [PMID: 17563747 DOI: 10.1038/sj.onc.1210567.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Signal transducer and activator of transcription 3 (Stat3) belongs to a family of latent cytoplasmic transcription factors important for cytokine signaling. Stat3 is constitutively activated in various tumors, and activated Stat3 itself also acts as an oncogene. Transcriptional activity of Stat3 is controlled by Tyr-phosphorylation, followed by dimerization and nuclear translocation. However, phosphorylation on Ser727 is indispensable for its maximal transcriptional activity with unclear mechanism. Here, we report that peptidyl-prolyl cis/trans isomerase 1 (Pin1), which specifically recognizes the pSer/Thr-Pro motifs on its target proteins, interacts with Stat3 upon cytokine/growth factor stimulation. Overexpression of Pin1 promotes Stat3 transcriptional activity and target gene expression, as well as recruitment of transcription coactivator, p300. These effects, however, were compromised in the Pin1-deficient cells, and were totally dependent on the Ser727 phosphorylation site. Finally, we showed that Pin1 enhances Stat3-mediated epithelial-mesenchymal transition in breast cancer cells induced by oncostatin M. Our data reveal a novel, Ser727 phosphorylation-dependent, post-translational regulation mechanism for Stat3.
Collapse
|
280
|
Ogasawara N, Tsukamoto T, Mizoshita T, Inada K, Cao X, Takenaka Y, Joh T, Tatematsu M. Mutations and nuclear accumulation of beta-catenin correlate with intestinal phenotypic expression in human gastric cancer. Histopathology 2007; 49:612-21. [PMID: 17163846 DOI: 10.1111/j.1365-2559.2006.02560.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AIMS Abnormal localization of beta-catenin is frequently observed in human gastric cancers. The aim of the present study was to evaluate relationships among gastrointestinal differentiation phenotypes, beta-catenin localization and mutations of Wnt signalling genes. METHODS AND RESULTS Seventy-seven regions in 39 gastric adenocarcinomas were classified according to beta-catenin localization and gastric and intestinal phenotypes. Cases with membranous beta-catenin localization showed a gradual decrease from gastric (G) (55% = 6/11) and gastric-and-intestinal-mixed (GI) (17% = 5/29) to intestinal (I) (0% = 0/21) phenotypes, while those with nuclear localization showed a concomitant increase: 18% (2/11), 41% (12/29), 95% (20/21) and 63% (10/16) for G, GI, I and null type (N), respectively (P < 0.001, membranous versus nuclear localization in G, GI through I). Mutations in exon 3 of the beta-catenin gene were found in G (50% = 1/2), GI (67% = 8/12), I (45% = 9/20) and N (0% = 0/10) regions with nuclear beta-catenin localization (GI versus N, P < 0.01; I versus N, P < 0.05). Adenomatous polyposis coli (APC) gene mutations were demonstrated only in GI, I and N types, irrespective of beta-catenin localization. Molecular analysis of these genes revealed 10 tumours to be heterogeneous out of 16 informative cases (62.5%). CONCLUSION Intestinal phenotypic expression is accompanied by a shift from membranous to cytoplasmic/nuclear accumulation of beta-catenin. In contrast, N-type regions may progress along a different pathway.
Collapse
|
281
|
Wiebke J, Moritz A, Cao X, Dolg M. Approaching actinide(+III) hydration from first principles. Phys Chem Chem Phys 2007; 9:459-65. [PMID: 17216061 DOI: 10.1039/b614092k] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A systematic computational approach to An(III) hydration on a density-functional level of theory, using quasi-relativistic 5f-in-core pseudopotentials and valence-only basis sets for the An(III) subsystems, is presented. Molecular structures, binding energies, hydration energies, and Gibbs free energies of hydration have been calculated for [An(III)(OH(2))(h)](3+) (h = 7, 8, 9) and [An(III)(OH(2))(h-1) * OH(2)](3+) (h = 8, 9), using large (7s6p5d2f1g)/[6s5p4d2f1g] An(III) and cc-pVQZ O and H basis sets within the COSMO implicit solvation model. An(III) preferred primary hydration numbers are found to be 8 for all An(III) at the gradient-corrected density-functional level of theory. Second-order Møller-Plesset perturbation theory predicts preferred primary hydration numbers of 9 and 8 for Ac(III)-Md(III) and No(III)-Lr(III), respectively.
Collapse
|
282
|
Cao X, Zhang W, Lockey R, Mohapatra S. ANP-NPRA Signaling Modulates Immunity By Altering TLR-2 Expression In Human Dendritic Cells (DCs). J Allergy Clin Immunol 2007. [DOI: 10.1016/j.jaci.2006.12.378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
283
|
Zhang J, Wang Q, Zhao D, Cao X. Induction of potent anti-tumor immunity by direct injection of Ad-LIGHT at the site of tumor inoculation. Cytotherapy 2007; 9:386-96. [PMID: 17573614 DOI: 10.1080/14653240701326749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND The aim of this study was to observe the therapeutic effects of adenovirus-mediated LIGHT gene transfer in murine B16 melanoma in vivo. METHODS C57BL/6 mice were inoculated subcutaneously with B16 cells to establish the murine melanoma model. The tumor-bearing mice were injected at the site of tumor inoculation with recombinant adenoviral vectors expressing the murine LIGHT gene. The tumor growth and survival period of tumor-bearing mice were observed. The splenic NK and CTL activity were measured in vitro by lactate dehydrogenase (LDH) release assay. The amounts of cytokines were determined with ELISA kits. RESULTS The LIGHT gene could be efficiently transduced into tumor tissue after injection of Ad-LIGHT. Treatment with Ad-LIGHT significantly inhibited the tumor growth and prolonged the survival period of the tumor-bearing mice. The splenic NK and CTL activity of the mice was also enhanced after LIGHT gene transfer. The production of IL-2 and IFN-gamma from lymphocytes derived from mice treated with Ad-LIGHT was increased significantly compared with control groups. DISCUSSION Our results indicate that local expression of the LIGHT gene can induce potent anti-tumor immunity and may be a promising treatment strategy for melanoma.
Collapse
|
284
|
Tang F, Liu J, Cao X, Tang Y, Liu Y. [P25]: CCR7, CCR8, CCR9 and CCR10 in the mouse hippocampus during and after pilocarpine induced status epilepticus. Int J Dev Neurosci 2006. [DOI: 10.1016/j.ijdevneu.2006.09.089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
285
|
Bagley R, Yao M, Weber W, Rouleau C, Barberio D, Cao X, Agata N, Kaplan J, Roberts B, Teicher B. 60 POSTER Targeting the chemokine receptor CXCR4 and ligand SDF-1/CXCL 12 in tumor vasculature and stroma. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70066-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
286
|
Cao X, Eu KW, Kumarasinghe MP, Li HH, Loi C, Cheah PY. Mapping of hereditary mixed polyposis syndrome (HMPS) to chromosome 10q23 by genomewide high-density single nucleotide polymorphism (SNP) scan and identification of BMPR1A loss of function. J Med Genet 2006; 43:e13. [PMID: 16525031 PMCID: PMC2563243 DOI: 10.1136/jmg.2005.034827] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Hereditary mixed polyposis syndrome (HMPS) is characterised by colonic polyps of mixed histological types that are autosomal dominantly inherited and eventually lead to colorectal cancer (CRC). Study of the molecular basis of HMPS will enhance our knowledge of the genetic basis of the mixed polyposis-carcinoma sequence in both hereditary and sporadic CRC. METHODS/RESULTS We performed a genomewide linkage search on 15 members of a three-generation HMPS family using the GeneChip Human Mapping 10K Array and identified a 7 cM putative linkage interval on chromosome 10q23. Subsequently, 32 members from two HMPS families were typed with nine microsatellite markers spanning the region and the linkage was confirmed with a maximum multi-point logarithm of the odds (LOD) score of 4.6 (p<0.001). The 10q23.1-10q23.31 haplotypes segregate with the disease in both families. We screened for mutations in four candidate genes within the linkage region and identified an 11 bp deletion in the bone morphogenesis protein receptor 1A (BMPR1A) gene in one family. CONCLUSIONS Our results indicate that BMPR1A mutation accounts for HMPS. The data suggest that inactivating BMPR1A can initiate colorectal tumourigenesis via the mixed polyposis-carcinoma sequence.
Collapse
|
287
|
Zhang HG, Liu C, Su K, Yu S, Zhang L, Zhang S, Wang J, Cao X, Grizzle W, Kimberly RP. A membrane form of TNFα presented by exosomes delays T cell activation-induced cell death. THE JOURNAL OF IMMUNOLOGY 2006. [DOI: 10.4049/jimmunol.177.3.2025-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
288
|
Han YH, Cao X, Lin B, Lin F, Kolluri SK, Stebbins J, Reed JC, Dawson MI, Zhang XK. Regulation of Nur77 nuclear export by c-Jun N-terminal kinase and Akt. Oncogene 2006; 25:2974-86. [PMID: 16434970 DOI: 10.1038/sj.onc.1209358] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Proapoptotic nuclear receptor family member Nur77 translocates from the nucleus to the mitochondria, where it interacts with Bcl-2 to trigger apoptosis. Nur77 translocation is induced by certain apoptotic stimuli, including the synthetic retinoid-related 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalenecarboxylic acid (AHPN)/CD437 class. In this study, we investigated the molecular mechanism by which AHPN/CD437 analog (E)-4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC) induces Nur77 nuclear export. Our results demonstrate that 3-Cl-AHPC effectively activated Jun N-terminal kinase (JNK), which phosphorylates Nur77. Inhibition of JNK activation by a JNK inhibitor suppressed 3-Cl-AHPC-induced Nur77 nuclear export and apoptosis. In addition, several JNK upstream activators, including the phorbol ester TPA, anisomycin and MAPK kinase kinase-1 (MEKK1), phosphorylated Nur77 and induced its nuclear export. However, Nur77 phosphorylation by JNK, although essential, was not sufficient for inducing Nur77 nuclear export. Induction of Nur77 nuclear export by MEKK1 required a prolonged MEKK1 activation and was attenuated by Akt activation. Expression of constitutively active Akt prevented MEKK1-induced Nur77 nuclear export. Conversely, transfection of dominant-negative Akt or treatment with a phosphatidylinositol 3-kinase (PI3-K) inhibitor accelerated MEKK1-induced Nur77 nuclear export. Furthermore, mutation of an Akt phosphorylation residue Ser351 in Nur77 abolished the effect of Akt or the PI3-K inhibitor. Together, our results demonstrate that both activation of JNK and inhibition of Akt play a role in translocation of Nur77 from the nucleus to the cytoplasm.
Collapse
MESH Headings
- Adamantane/analogs & derivatives
- Adamantane/pharmacology
- Anisomycin/pharmacology
- Apoptosis/drug effects
- Cell Line, Tumor/drug effects
- Cell Line, Tumor/metabolism
- Cell Line, Tumor/ultrastructure
- Cell Nucleus/metabolism
- Cinnamates/pharmacology
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Enzyme Activation/drug effects
- Flavonoids/pharmacology
- Humans
- Imidazoles/pharmacology
- JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors
- JNK Mitogen-Activated Protein Kinases/physiology
- MAP Kinase Kinase 7/genetics
- MAP Kinase Kinase 7/pharmacology
- MAP Kinase Kinase Kinase 1/physiology
- Mutagenesis, Site-Directed
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Phosphatidylinositol 3-Kinases/physiology
- Phosphoinositide-3 Kinase Inhibitors
- Phosphorylation/drug effects
- Protein Processing, Post-Translational/drug effects
- Protein Transport/drug effects
- Proto-Oncogene Proteins c-akt/antagonists & inhibitors
- Proto-Oncogene Proteins c-akt/physiology
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Pyridines/pharmacology
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Recombinant Fusion Proteins/pharmacology
- Tetradecanoylphorbol Acetate/pharmacology
- Transcription Factors/genetics
- Transcription Factors/metabolism
Collapse
|
289
|
Huang G, Chen Y, Lu H, Cao X. Coupling mitochondrial respiratory chain to cell death: an essential role of mitochondrial complex I in the interferon-β and retinoic acid-induced cancer cell death. Cell Death Differ 2006; 14:327-37. [PMID: 16826196 DOI: 10.1038/sj.cdd.4402004] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Combination of retinoic acids (RAs) and interferons (IFNs) has synergistic apoptotic effects and is used in cancer treatment. However, the underlying mechanisms remain unknown. Here, we demonstrate that mitochondrial respiratory chain (MRC) plays an essential role in the IFN-beta/RA-induced cancer cell death. We found that IFN-beta/RA upregulates the expression of MRC complex subunits. Mitochondrial-nuclear translocation of these subunits was not observed, but overproduction of reactive oxygen species (ROS), which causes loss of mitochondrial function, was detected upon IFN-beta/RA treatment. Knockdown of GRIM-19 (gene associated with retinoid-interferon-induced mortality-19) and NDUFS3 (NADH dehydrogenase (ubiquinone) Fe-S protein 3), two subunits of MRC complex I, by siRNA in two cancer cell lines conferred resistance to IFN-beta/RA-induced apoptosis and reduced ROS production. In parallel, expression of late genes induced by IFN-beta/RA that are directly involved in growth inhibition and cell death was also repressed in the knockdown cells. Our data suggest that the MRC regulates IFN-beta/RA-induced cell death by modulating ROS production and late gene expression.
Collapse
|
290
|
Bagley RG, Rouleau C, Weber W, Cao X, Teicher BA. Model development of human sarcomas for identification and validation of new targets. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.13080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
13080 Background: Soft tissue sarcomas are malignant tumors that can develop from a variety of tissues. There is a lack of targeted therapies directed specifically against sarcomas with surgery, radiation, and chemotherapy being the standard of care. By employing multiple strategies, new targets that may advance sarcoma therapy can be identified. Methods: Profiling of secreted cytokines that may drive tumor growth was performed on cell lines representing osteosarcomas, liposarcomas, fibrosarcomas, and rhabdomysarcomas. Of 27 cytokines analyzed from cultured media, the following were most highly expressed: IL-6, IL-8, IL-12p40, SDF-1, and MCP-1. Results: Results were compared against gene expression data from publicly available oligonucleotide microarrays derived from human tumors. Ewing’s sarcoma and rhabdomysarcoma samples confirmed higher expression levels of VEGF. Further analysis of array data from 16 classes of sarcomas and 181 tumors indicated that IL-7 was more predominantly expressed than IL-6 and IL-8. To evaluate efficacy of novel agents, xenograft models were established using human cell lines A673 rhabdomyosarcoma and SW872 liposarcoma. Tumor growth and response to therapy was characterized. Paclitaxel (75 mg/kg, days 7, 9, 11) delayed tumor growth for about one week following treatment in both models, however only SW872 liposarcoma tumors responded after dosing with anti-angiogenic agent, Avastin (5 mg/kg, days 4, 7, 11, 14, 17, and 21). Conclusions: In addition to killing cancer cells, destabilization of the vasculature/stroma may be beneficial. Immunohistochemical (IHC) analysis was performed on sarcoma tumors from the clinic. CD31 and SMA staining identified vasculature and stromal regions. Subsequent to identification of novel targets specific to sarcomas, IHC methods can further define localization of antigens between various tumor components. A variety of techniques are being utilized in order to recognize new targets in sarcomas. Cell-based assays and preclinical models are incorporated into the drug development pathway to evaluate novel drugs. Analysis of differential gene expression between tumor types and amongst sarcoma subtypes will be essential in identifying which patient population will gain the greatest benefits from targeted therapies. [Table: see text]
Collapse
|
291
|
Lim CP, Phan TT, Lim IJ, Cao X. Stat3 contributes to keloid pathogenesis via promoting collagen production, cell proliferation and migration. Oncogene 2006; 25:5416-25. [PMID: 16619044 DOI: 10.1038/sj.onc.1209531] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Keloids, partially considered as benign tumors, represent the most extreme example of cutaneous scarring that uniquely afflicts humans as a pathological response to wound healing. It is characterized by excessive deposition of collagen and other extracellular matrix components by dermal fibroblasts. Upon cutaneous injury, cocktails of chemokines, cytokines and growth factors are secreted temporally and spatially to direct appropriate responses from neutrophils, macrophages, keratinocytes and fibroblasts to facilitate normal wound healing. Signal transducer and activator of transcription 3 (Stat3) is an oncogene and a latent transcription factor activated by various cytokines and growth factors. We investigated the possible role of Stat3 in keloid scar pathogenesis by examining skin tissue and cultured fibroblasts from keloid-scarred patients. We observed enhanced expression and phosphorylation of Stat3 in keloid scar tissue, and in cultured keloid fibroblasts (KFs) in vitro. Increased activation of Janus kinase (Jak)2, but not Jak1, was detected in KFs, and suppression of Jak2 by its inhibitor repressed Stat3 Y705 phosphorylation. Inhibition of Stat3 expression and phosphorylation by short interfering RNA or Cucurbitacin I resulted in the loss of collagen production, impaired proliferation and delayed cell migration in KFs. We show, for the first time, a role of Stat3 in keloid pathogenesis. Inhibitors of Stat3 may be useful therapeutic strategies for the prospective treatment of keloid scars.
Collapse
|
292
|
Wei Z, Mousseau DD, Dai Y, Cao X, Li XM. Haloperidol induces apoptosis via the sigma2 receptor system and Bcl-XS. THE PHARMACOGENOMICS JOURNAL 2006; 6:279-88. [PMID: 16462815 DOI: 10.1038/sj.tpj.6500373] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Toxicity of the typical antipsychotic haloperidol (HAL) comprises an apoptotic component that we link to pro-apoptotic Bcl-XS in PC12 preneuronal and N2a neuroblastoma cells. The mitochondrial translocation of Bcl-XS and its interaction with the pore-forming voltage-dependent anion channel (VDAC) correlates with the redistribution of cytochrome c and the cleavage of Poly(ADP-ribose) polymerase. Haloperidol-induced apoptosis is mediated by the sigma2 (sigma2) receptor system and does not involve the expected antagonism of the dopamine D(2) receptor, nor is it influenced by Vitamin E- or p53/Bax-mediated events. Pathological relevance is demonstrated by the cytotoxic synergism between HAL and the Alzheimer disease-related peptide beta-amyloid(1-40), which correlates with Bcl-XS expression and its interaction with VDAC, and with cytosolic cytochrome c translocation. These data provide for a unique apoptotic mechanism that could underscore the clinical risks associated with HAL, particularly following chronic regimens or in the elderly.
Collapse
|
293
|
Cao X, Qin J, Xie Y, Khan O, Dowd F, Scofield M, Lin MF, Tu Y. Regulator of G-protein signaling 2 (RGS2) inhibits androgen-independent activation of androgen receptor in prostate cancer cells. Oncogene 2006; 25:3719-34. [PMID: 16449965 DOI: 10.1038/sj.onc.1209408] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hormones acting through G protein-coupled receptors (GPCRs) can cause androgen-independent activation of androgen receptor (AR) in prostate cancer cells. Regulators of G-protein signaling (RGS) proteins, through their GTPase activating protein (GAP) activities, inhibit GPCR-mediated signaling by inactivating G proteins. Here, we identified RGS2 as a gene specifically downregulated in androgen-independent prostate cancer cells. Expression of RGS2, but not other RGS proteins, abolished androgen-independent AR activity in androgen-independent LNCaP cells and CWR22Rv1 cells. In LNCaP cells, RGS2 inhibited G(q)-coupled GPCR signaling. Expression of exogenous wild-type RGS2, but not its GAP-deficient mutant, significantly reduced AR activation by constitutively activated G(q)Q209L mutant whereas silencing endogenous RGS2 by siRNA enhanced G(q)Q209L-stimulated AR activity. RGS2 had no effect on RGS-insensitive G(q)Q209L/G188S-induced AR activation. Furthermore, extracellular signal-regulated kinase 1/2 (ERK1/2) was found to be involved in RGS2-mediated regulation of androgen-independent AR activity. In addition, RGS2 functioned as a growth suppressor for androgen-independent LNCaP cells whereas androgen-sensitive LNCaP cells with RGS2 silencing had a growth advantage under steroid-reduced conditions. Finally, RGS2 expression level was significantly decreased in human prostate tumor specimens. Taken together, our results suggest RGS2 as a novel regulator of AR signaling and its repression may be an important step during prostate tumorigenesis and progression.
Collapse
|
294
|
Fang H, Tong W, Perkins R, Shi L, Hong H, Cao X, Xie Q, Yim SH, Ward JM, Pitot HC, Dragan YP. Bioinformatics approaches for cross-species liver cancer analysis based on microarray gene expression profiling. BMC Bioinformatics 2005; 6 Suppl 2:S6. [PMID: 16026603 PMCID: PMC1637037 DOI: 10.1186/1471-2105-6-s2-s6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Background The completion of the sequencing of human, mouse and rat genomes and knowledge of cross-species gene homologies enables studies of differential gene expression in animal models. These types of studies have the potential to greatly enhance our understanding of diseases such as liver cancer in humans. Genes co-expressed across multiple species are most likely to have conserved functions. We have used various bioinformatics approaches to examine microarray expression profiles from liver neoplasms that arise in albumin-SV40 transgenic rats to elucidate genes, chromosome aberrations and pathways that might be associated with human liver cancer. Results In this study, we first identified 2223 differentially expressed genes by comparing gene expression profiles for two control, two adenoma and two carcinoma samples using an F-test. These genes were subsequently mapped to the rat chromosomes using a novel visualization tool, the Chromosome Plot. Using the same plot, we further mapped the significant genes to orthologous chromosomal locations in human and mouse. Many genes expressed in rat 1q that are amplified in rat liver cancer map to the human chromosomes 10, 11 and 19 and to the mouse chromosomes 7, 17 and 19, which have been implicated in studies of human and mouse liver cancer. Using Comparative Genomics Microarray Analysis (CGMA), we identified regions of potential aberrations in human. Lastly, a pathway analysis was conducted to predict altered human pathways based on statistical analysis and extrapolation from the rat data. All of the identified pathways have been known to be important in the etiology of human liver cancer, including cell cycle control, cell growth and differentiation, apoptosis, transcriptional regulation, and protein metabolism. Conclusion The study demonstrates that the hepatic gene expression profiles from the albumin-SV40 transgenic rat model revealed genes, pathways and chromosome alterations consistent with experimental and clinical research in human liver cancer. The bioinformatics tools presented in this paper are essential for cross species extrapolation and mapping of microarray data, its analysis and interpretation.
Collapse
|
295
|
Cao X, Jiang H, Zhang X. Polymorphic karyotypes and sex chromosomes in the tufted deer (Elaphodus cephalophus): cytogenetic studies and analyses of sex chromosome-linked genes. Cytogenet Genome Res 2005; 109:512-8. [PMID: 15905647 DOI: 10.1159/000084212] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Accepted: 09/06/2004] [Indexed: 11/19/2022] Open
Abstract
Different diploid chromosome numbers have been reported for the tufted deer Elaphodus cephalophus (female, 2n = 46/47; male, 2n = 47/48) in earlier reports. In the present study, chromosomal analysis of seven tufted deer (5 male symbol, 2 female symbol) revealed that the karyotype of these animals contains 48 chromosomes, including a pair of large heteromorphic chromosomes in the male. C-banding revealed these chromosomes to be very rich in constitutive heterochromatin. Chromosome banding and PCR of sex chromosome-linked genes (SRY, ZFX, ZFY) performed on DOP-PCR products of single microdissected X and Y chromosomes confirmed that the large telocentric chromosome without secondary constriction is the X chromosome whereas the subtelocentric chromosome is the Y. The increased size of both, the X and Y chromosome, appears to be at least partially attributable to the presence of substantial amounts of heterochromatin.
Collapse
|
296
|
Tsafriri A, Cao X, Ashkenazi H, Motola S, Popliker M, Pomerantz SH. Resumption of oocyte meiosis in mammals: on models, meiosis activating sterols, steroids and EGF-like factors. Mol Cell Endocrinol 2005; 234:37-45. [PMID: 15836951 DOI: 10.1016/j.mce.2004.09.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2004] [Accepted: 09/20/2004] [Indexed: 01/20/2023]
Abstract
De novo synthesis of meiosis activating sterols (MAS) was stimulated by LH- and AY-9944 in rat cultured follicles and cumulus oocyte complexes (COCs), but could not be measured in denuded oocytes. Thus, MAS synthesized by the somatic compartment of the follicle could serve as a signal for the resumption of meiosis. Nevertheless, the delay in germinal vesicle breakdown (GVB) after MAS or AY-9944 stimulation as compared with gonadotropins, obtained by several groups, remains the strongest evidence against the suggested role of MAS as an essential mediator of LH in meiosis resumption. Recently several studies using mammalian COCs in culture have implied that steroids, like in fish and amphibians, serve as signals in mediating the LH/hCG stimulation of meiosis. However, in these studies there was no clear distinction between the requirement for steroids for the acquisition of meiotic competence, oocyte and follicle wellbeing or as a signal for meiotic resumption. Further, some of the authors overlooked earlier studies showing that blocking ovarian or follicular steroidogenesis does not affect GVB, the first step of meiosis resumption. Finally, in vivo and in vitro studies in the rat confirm and extend recent studies showing that locally produced and released EGF-like factors, such as epiregulin, seem to mediate at least part of the LH/hCG actions on oocyte maturation and release of ova at ovulation.
Collapse
|
297
|
Gordon SH, Cao X, Mohamed A, Willett JL. Infrared spectroscopy method reveals hydrogen bonding and intermolecular interaction between components in polymer blends. J Appl Polym Sci 2005. [DOI: 10.1002/app.21775] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
298
|
Ashkenazi H, Cao X, Motola S, Popliker M, Conti M, Tsafriri A. Epidermal growth factor family members: endogenous mediators of the ovulatory response. Endocrinology 2005; 146:77-84. [PMID: 15459120 DOI: 10.1210/en.2004-0588] [Citation(s) in RCA: 226] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous studies showed that epidermal growth factor (EGF) and TGFalpha mimic the action of LH on the resumption of oocyte maturation. We tested whether EGF-like agents, such as amphiregulin (AR), epiregulin (ER), and betacellulin (BTC), also mediate the LH stimulation of the ovulatory response in the rat. LH induced transient follicular expression of AR, ER, and BTC mRNA, reaching a maximum after 3-h incubation. Furthermore, the addition of ER, AR, and BTC to the culture medium could mimic some of LH actions. AR and ER fully simulated LH-induced resumption of meiosis in vitro, whereas BTC was less effective. To study the putative involvement of EGF-like factors in mediation of LH signal, the effect of the EGF receptor kinase inhibitor AG1478 was tested. When added with LH, AG1478, but not its inactive analog AG43, reduced EGF receptor phosphorylation and oocyte maturation compared with follicles treated with LH only. In addition to the inhibition of resumption of meiosis, AG1478 administration into the bursa (3 microg/bursa) resulted in 51% (P < 0.0005) inhibition of ovulation in the treated ovaries, compared with the untreated contralateral ones, as well as to the vehicle-treated ovaries (P < 0.02). LH, as well as ER, induced the expression of genes associated with the ovulatory response like rat hyaluronan synthase-2, cyclooxygenase-2, and TNFalpha-stimulated gene 6 mRNA, whereas AG1478 inhibited this effect of LH. Release of EGF-like factors from the membrane is dependent on activated metalloproteases. Indeed, Galardin, a broad-spectrum metalloprotease inhibitor, but not a specific matrix metalloprotease 2 and 9 inhibitor, suppressed meiotic maturation induced by LH. Conversely, meiotic maturation induced by ER was not affected by Galardin, thus, supporting the notion that LH releases follicular membrane-bound EGF-like agents. In summary, EGF-like factors such as ER, AR, and BTC seem to mediate, at least partially, the LH stimulation of oocyte maturation, ovulatory enzyme expression, and ovulation.
Collapse
|
299
|
McMahon CJ, Nagueh SF, Eapen RS, Dreyer WJ, Finkelshtyn I, Cao X, Eidem BW, Bezold LI, Denfield SW, Towbin JA, Pignatelli RH. Echocardiographic predictors of adverse clinical events in children with dilated cardiomyopathy: a prospective clinical study. Heart 2004; 90:908-15. [PMID: 15253966 PMCID: PMC1768368 DOI: 10.1136/hrt.2003.020966] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES To compare tissue Doppler (TD) velocities between patients with dilated cardiomyopathy (DCM) and normal controls and to determine whether TD velocities, Tei index, right ventricular fractional area change, and left ventricular ejection fraction (LVEF) predict adverse clinical outcomes in children with DCM. METHODS Prospective evaluation of children with DCM. RESULTS 54 children with DCM and 54 age and sex matched control group participants were studied. Mitral inflow velocities were similar for both groups except for decreased mitral deceleration time in patients with DCM. Systolic and diastolic TD velocities at the mitral annulus (septal and lateral sides) and tricuspid annulus were significantly reduced in children with DCM compared with controls (p < 0.001 for each). By multivariate analysis, after adjustment for Tei index and right ventricular fractional area change, decreased LVEF and tricuspid velocity during early diastole (Ea) were predictors of the primary end point (PEP), a composite end point consisting of need for hospitalisation or the outcome transplantation or death. Tricuspid Ea velocity < 8.5 cm/s had 87% specificity and 60% sensitivity for reaching the PEP. LVEF < 30% had 68% specificity and 74% sensitivity for the PEP. Combined LVEF < 30% and tricuspid Ea < 11.5 cm/s had 100% specificity and 44% sensitivity for the PEP. CONCLUSIONS Children with DCM have significantly lower TD velocities than normal controls. In such cases, lower LVEF (< 30%) is more sensitive but less specific than lower tricuspid Ea velocities (< 8.5 cm/s) in predicting which patients are at risk of hospitalisation, transplantation, or death.
Collapse
|
300
|
Bagley R, Dash A, Cao X, Lodie T, Madden S, Tubo R, Teicher B. 85 Progenitor cells derived from human bone marrow contribute to the growth of breast cancer cells. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80093-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|