다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

We describe the landscape of somatic genomic alterations based on multidimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors, including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer.

The somatic genomic landscape of glioblastoma

PLoS BIOLOGY Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor Jean-Philippe Coppe 1 , Christopher K. Patil 1[ , Francis Rodier 1,2[ , Yu Sun 3 , Denise P. Mun oz 1,2 , Joshua Goldstein 1¤ , Peter S. Nelson 3 , Pierre-Yves Desprez 1,4 , Judith Campisi 1,2* 1 Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America, 2 Buck Institute for Age Research, Novato, California, United States of America, 3 Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America, 4 California Pacific Medical Center Research Institute, San Francisco, California, United States of America Cellular senescence suppresses cancer by arresting cell proliferation, essentially permanently, in response to oncogenic stimuli, including genotoxic stress. We modified the use of antibody arrays to provide a quantitative assessment of factors secreted by senescent cells. We show that human cells induced to senesce by genotoxic stress secrete myriad factors associated with inflammation and malignancy. This senescence-associated secretory phenotype (SASP) developed slowly over several days and only after DNA damage of sufficient magnitude to induce senescence. Remarkably similar SASPs developed in normal fibroblasts, normal epithelial cells, and epithelial tumor cells after genotoxic stress in culture, and in epithelial tumor cells in vivo after treatment of prostate cancer patients with DNA- damaging chemotherapy. In cultured premalignant epithelial cells, SASPs induced an epithelial–mesenchyme transition and invasiveness, hallmarks of malignancy, by a paracrine mechanism that depended largely on the SASP factors interleukin (IL)-6 and IL-8. Strikingly, two manipulations markedly amplified, and accelerated development of, the SASPs: oncogenic RAS expression, which causes genotoxic stress and senescence in normal cells, and functional loss of the p53 tumor suppressor protein. Both loss of p53 and gain of oncogenic RAS also exacerbated the promalignant paracrine activities of the SASPs. Our findings define a central feature of genotoxic stress-induced senescence. Moreover, they suggest a cell-nonautonomous mechanism by which p53 can restrain, and oncogenic RAS can promote, the development of age-related cancer by altering the tissue microenvironment. Citation: Coppe JP, Patil CK, Rodier F, Sun Y, Mun oz DP, et al. (2008) Senescence-associated secretory phenotypes reveal cell-nonautonomous functions of oncogenic RAS and the p53 tumor suppressor. PLoS Biol 6(12): e301. doi:10.1371/journal.pbio.0060301 Introduction Cancer is a multistep disease in which cells acquire increasingly malignant phenotypes. These phenotypes are acquired in part by somatic mutations, which derange normal controls over cell proliferation (growth), survival, invasion, and other processes important for malignant tumorigenesis [1]. In addition, there is increasing evidence that the tissue microenvironment is an important determinant of whether and how malignancies develop [2,3]. Normal tissue environ- ments tend to suppress malignant phenotypes, whereas abnormal tissue environments such at those caused by inﬂammation can promote cancer progression. Cancer development is restrained by a variety of tumor suppressor genes. Some of these genes permanently arrest the growth of cells at risk for neoplastic transformation, a process termed cellular senescence [4–6]. Two tumor suppressor pathways, controlled by the p53 and p16INK4a/pRB proteins, regulate senescence responses. Both pathways integrate multiple aspects of cellular physiology and direct cell fate towards survival, death, proliferation, or growth arrest, depending on the context [7,8]. Several lines of evidence indicate that cellular senescence is a potent tumor-suppressive mechanism [4,9,10]. Many poten- tially oncogenic stimuli (e.g., dysfunctional telomeres, DNA PLoS Biology | www.plosbiology.org damage, and certain oncogenes) induce senescence [6,11]. Moreover, mutations that dampen the p53 or p16INK4a/pRB pathways confer resistance to senescence and greatly increase cancer risk [12,13]. Most cancers harbor mutations in one or both of these pathways [14,15]. Lastly, in mice and humans, a senescence response to strong mitogenic signals, such as those delivered by certain oncogenes, prevents premalignant lesions from progressing to malignant cancers [16–19]. Academic Editor: Julian Downward, Cancer Research UK, United Kingdom Received June 27, 2008; Accepted October 22, 2008; Published December 2, 2008 Copyright: O 2008 Coppe et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abbreviations: CM, conditioned medium; DDR, DNA damage response; ELISA, enzyme-linked immunosorbent assay; EMT, epithelial–mesenchymal transition; GSE, genetic suppressor element; IL, interleukin; MIT, mitoxantrone; PRE, presenescent; PrEC, normal human prostate epithelial cell; REP, replicative exhaustion; SASP, senescence-associated secretory phenotype; SEN, senescent; shRNA, short hairpin RNA; XRA, X-irradiation * To whom correspondence should be addressed. E-mail: jcampisi@lbl.gov [ These authors contributed equally to this work. ¤ Current address: Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America December 2008 | Volume 6 | Issue 12 | e301

Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor with poor clinical outcomes. Increasing amount of long non-coding RNAs (lncRNAs) have been revealed to be implicated in the carcinogenesis and progression of HCC. However, the expressions, clinical significances, and roles of most lncRNAs in HCC are still unknown. The expression of lncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) in HCC tissues and cell lines was detected by qRT-PCR and fluorescence in situ hybridization. Immunoblotting, CCK-8, EdU, colony formation and flow cytometry were performed to investigate the role of MCM3AP-AS1 in HCC cell proliferation, cell cycle and apoptosis in vitro. A subcutaneous tumor mouse model was constructed to analyze in vivo growth of HCC cells after MCM3AP-AS1 knockdown. The interactions among MCM3AP-AS1, miR-194-5p and FOXA1 were measured by RNA pull-down, RNA immunoprecipitation and luciferase reporter assay. We revealed a novel oncogenic lncRNA MCM3AP-AS1, which is overexpressed in HCC and positively correlated with large tumor size, high tumor grade, advanced tumor stage and poor prognosis of HCC patients. MCM3AP-AS1 knockdown suppressed HCC cell proliferation, colony formation and cell cycle progression, and induced apoptosis in vitro, and depletion of MCM3AP-AS1 inhibited tumor growth of HCC in vivo. Mechanistically, MCM3AP-AS1 directly bound to miR-194-5p and acted as competing endogenous RNA (ceRNA), and subsequently facilitated miR-194-5p’s target gene forkhead box A1 (FOXA1) expression in HCC cells. Interestingly, FOXA1 restoration rescued MCM3AP-AS1 knockdown induced proliferation inhibition, G1 arrest and apoptosis of HCC cells. Our results recognized MCM3AP-AS1 as a novel oncogenic lncRNA, which indicated poor clinical outcomes in patients with HCC. MCM3AP-AS1 exerted an oncogenic role in HCC via targeting miR-194-5p and subsequently promoted FOXA1 expression. Our findings suggested that MCM3AP-AS1 could be a potential prognostic biomarker and therapeutic target for HCC.

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A novel lncRNA MCM3AP-AS1 promotes the growth of hepatocellular carcinoma by targeting miR-194-5p/FOXA1 axis

The signaling networks that drive the aging process, associated functional deterioration, and pathologies has captured the scientific community's attention for decades. While many theories exist to explain the aging process, the production of reactive oxygen species (ROS) provides a signaling link between engagement of cellular senescence and several age-associated pathologies. Cellular senescence has evolved to restrict tumor progression but the accompanying senescence-associated secretory phenotype (SASP) promotes pathogenic pathways. Here, we review known biological theories of aging and how ROS mechanistically control senescence and the aging process. We also describe the redox-regulated signaling networks controlling the SASP and its important role in driving age-related diseases. Finally, we discuss progress in designing therapeutic strategies that manipulate the cellular redox environment to restrict age-associated pathology.

Redox control of senescence and age-related disease

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor and has a poor prognosis. We, here, report a potent antitumor effect of berberine, an isoquinoline alkaloid, on GBM. Berberine was found to have an IC50 that is much lower than temozolomide in vitro in U87, U251, and U118 glioblastoma cells. Although previous studies showed that berberine primarily exerts its anticancer effect by inducing cell-cycle arrest, apoptosis, and autophagy, we observed that the antitumor effect of berberine on glioblastoma cells was primarily achieved through induction of cellular senescence. In glioblastoma cells treated with berberine, the level of epidermal growth factor receptor (EGFR) was greatly reduced. Examination of the activities of the kinases downstream of EGFR revealed that the RAF-MEK-ERK signaling pathway was remarkably inhibited, whereas AKT phosphorylation was not altered. Pharmacologic inhibition or RNA interference of EGFR similarly induced cellular senescence of glioblastoma cells. Furthermore, the cellular senescence induced by berberine could be rescued by introduction of a constitutive active MKK. Berberine also potently inhibited the growth of tumor xenografts, which was accompanied by downregulation of EGFR and induction of senescence. Our findings thus revealed a new route by which berberine exerts its anticancer activity. Because EGFR is commonly upregulated in glioblastoma, the demonstration of effective inhibition of EGFR by berberine points to the possibility of using berberine in the treatment of patients with glioblastoma.

https://mct.aacrjournals.org/content/molcanther/early/2015/01/26/1535-7163.MCT-14-0634.full.pdf

Berberine Induces Senescence of Human Glioblastoma Cells by Downregulating the EGFR–MEK–ERK Signaling Pathway

Activation of Wnt/β-catenin signalling is frequently observed in many types of cancer including hepatocellular carcinoma (HCC). We recently reported that cullin 4B (CUL4B), a scaffold protein that assembles CRL4B ubiquitin ligase complexes, is overexpressed in many types of solid tumours and contributes to epigenetic silencing of tumour suppressors. In this study, we characterized the function of CUL4B in HCC and investigated whether CUL4B is involved in the regulation of Wnt/β-catenin signalling. CUL4B and β-catenin were frequently up-regulated and positively correlated in HCC tissues. CUL4B activated Wnt/β-catenin signalling by protecting β-catenin from GSK3-mediated degradation, achieved through CUL4B-mediated epigenetic silencing of Wnt pathway antagonists. Knockdown of CUL4B resulted in the up-regulation of Wnt signal antagonists such as DKK1 and PPP2R2B. Simultaneous knockdown of PPP2R2B partially reversed the down-regulation of β-catenin signalling caused by CUL4B depletion. Furthermore, CRL4B promoted the recruitment and/or retention of PRC2 at the promoters of Wnt antagonists and CUL4B knockdown decreased the retention of PRC2 components as well as H3K27me3. Knockdown of CUL4B reduced the proliferation, colony formation, and invasiveness of HCC cells in vitro and inhibited tumour growth in vivo, and these effects were attenuated by introduction of exogenous β-catenin or simultaneous knockdown of PPP2R2B. Conversely, ectopic expression of CUL4B enhanced the proliferation and invasiveness of HCC cells. We conclude that CUL4B can up-regulate Wnt/β-catenin signalling in human HCC through transcriptionally repressing Wnt antagonists and thus contributes to the malignancy of HCC.

CUL4B activates Wnt/β-catenin signalling in hepatocellular carcinoma by repressing Wnt antagonists.

Mammalian cells may undergo permanent growth arrest/senescence when they incur excessive DNA damage. As a key player during DNA damage response (DDR), p53 transactivates an array of target genes that are involved in various cellular processes including the induction of cellular senescence. Chemokine receptor CXCR2 was previously reported to mediate replicative and oncogene-induced senescence in a DDR and p53-dependent manner. Here, we report that CXCR2 is upregulated in various types of cells in response to genotoxic or oxidative stress. Unexpectedly, we found that the upregulation of CXCR2 depends on the function of p53. Like other p53 target genes such as p21, CXCR2 is transactivated by p53. We identified a p53-binding site in the CXCR2 promoter that responds to changes in p53 functional status. Thus, CXCR2 may act downstream of p53. While the senescence-associated secretory phenotype (SASP) exhibits a kinetics that is distinct from that of CXCR2 expression and does not require p53, it reinforces senescence. We further showed that the cellular senescence caused by CXCR2 upregulation is mediated by p38 activation. Our results thus demonstrate CXCR2 as a critical mediator of cellular senescence downstream of p53 in response to DNA damage.

Chemokine receptor CXCR2 is transactivated by p53 and induces p38-mediated cellular senescence in response to DNA damage.

Reactive oxygen species (ROS) are known to cause many types of DNA lesions that could be converted into cancer-promoting genetic alterations. Evidence showed that tumor suppressor p53 plays an important role in regulating the generation of cellular ROS, either by reducing oxidative stress under physiological and mildly stressed conditions, or by promoting oxidative stress under highly stressed conditions. In this report we characterized the effect of oxidative stress on the induction of micronuclei, especially the subclass marked by pan-staining of γ-H2AX or MN-γ-H2AX (+). We found that MN-γ-H2AX (+) were more responsive to hydrogen peroxide (H2O2) than the MN-γ-H2AX (−). In human and mouse cells that are deficient in p53, the frequency of MN-γ-H2AX (+) is significantly elevated, but can be attenuated by antioxidant N-acetylcysteine (NAC). Depletion of p53-regulated antioxidant gene SESN1 by RNA interference also resulted in an elevation of MN-γ-H2AX (+). Furthermore, we found that in cells that were depleted of p400 by RNAi, and therefore were experiencing increased ROS, the frequency of MN-γ-H2AX (+), but not that of MN-γ-H2AX (−), was significantly induced. We further demonstrated that the induction of MN-γ-H2AX (+) by replication stress can also be attenuated by NAC, and that H2O2 also leads to increased phosphorylation of Chk1 and Rad17 that mimics replication stress, suggesting that replication stress and oxidative stress are intertwined and may reinforce each other in driving genomic instability. Our findings illustrate the importance of p53-regulated redox level in the maintenance of genomic stability.

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Zhao Wei

Papers

Berberine Induces Senescence of Human Glioblastoma Cells by Downregulating the EGFR–MEK–ERK Signaling Pathway

CUL4B activates Wnt/β-catenin signalling in hepatocellular carcinoma by repressing Wnt antagonists.

Chemokine receptor CXCR2 is transactivated by p53 and induces p38-mediated cellular senescence in response to DNA damage.

Oxidative stress preferentially induces a subtype of micronuclei and mediates the genomic instability caused by p53 dysfunction

CUL4B impedes stress-induced cellular senescence by dampening a p53-reactive oxygen species positive feedback loop