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  • American Association for Cancer Research (AACR)  (2)
  • Li, Shulin  (2)
  • White, Jon  (2)
Materialart
Verlag/Herausgeber
  • American Association for Cancer Research (AACR)  (2)
Sprache
Erscheinungszeitraum
Fachgebiete(RVK)
  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 75, No. 15_Supplement ( 2015-08-01), p. 3900-3900
    Kurzfassung: Objective: Genome-wide analysis enables predictive modeling of genetic pathways driving many cancers. While somatic mutations and patterns reflecting key pathways have been identified for many cancers, an integrated analysis of driver mutations identified through mouse/human genetics have yet to be comprehensively defined for hepatocellular cancer (HCC). Previously our group and others have identified that loss of TGF-β signaling leads to spontaneous HCC development, through mouse models and human genetics. Patients with hepatocellular cancer have a poor survival of 9-11 months. Recent clinical studies show that targeting TGF-β improves survival up to 21 months, yet prognostic significances are undefined. The relationships between patterns of mutations and transcriptomic phenotypes for the TGF-β pathway are unclear. Methods: (1) We analyzed the transcriptome of 488 hepatocellular cancers and screened for mutations in the TGF-β pathway in 202 HCCs from The Cancer Genome Atlas (TCGA). (2) Increased levels of TGF-β-related genes were designated as an “activated” signature that is associated with hepatic fibrosis. Conversely, decreased levels of TGF-β-related genes were defined as an “inactivated” signature, which was associated with the loss of TGF-β tumor suppressor function. (3) We further performed high-fidelity (80x) whole-genome sequence analysis and transcriptome sequencing analysis of eight additional HCCs to define the role of TGF-β in their development and characterize a potential novel “driver mutations” in HCV- and alcohol-associated hepatocellular cancer. (4) We validated the clinical relevance of β2SP alterations in 22 human liver specimens. Results: (1) Transcriptomic analyses revealed aberrant TGF-β superfamily profiles in 72% of hepatocellular cancers, with mutations in 38% of patients. (2) HCCs characterized by the “inactivated” TGF-β signature were associated with a significantly poorer survival particularly in early stage HCCs, compared to HCCs with the “activated” TGF-β signature (p = 0.0027). (3) We observed the greatest number of functional mutations in the SPTBN1 gene (6%), which encodes a tumor suppressor TGF-β/Smad3 adaptor protein. (4) Furthermore, we found a strong association between DNA damage response genes and the TGF-β pathway at both transcriptomic and genomic levels. Conclusions: The TGF-β pathway plays a pivotal role in liver tumorigenesis and the molecular signatures we characterize here appear to have prognostic significance. The additional association with the DNA repair pathway supports new approaches to developing biomarkers. Targeting of TGF-β, has the potential for improving survival of liver cancer. Citation Format: Jian Chen, Jiun-Sheng Chen, Jianping Zhang, Liem Phan, Nina M. Muñoz, Lior H Katz, YoungJin Gi, Vipin Kumar Menon, Ji-Hyun Shin, Yun Seong Jeong, Wilma Jogunoori, Patrizia Farci, Kirti Shetty, Xiaoping Su, Tej K Pandita, Jon White, Bibhuti Mishra, Fausto Zamboni, Xifeng Wu, Asif Rashid, Shulin Li, Milind Javle, Mien-Chie Hung, Franklin Herlong, Marta Davila, John Stroehlein, Kenna R Shaw, Xuemei Wang, Jeffrey S Morris, Rehan Akbani, Lopa Mishra. Genomic landscape of human cancer reveals dysregulated TGF-β signaling with prognostic significance. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3900. doi:10.1158/1538-7445.AM2015-3900
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2015
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 14_Supplement ( 2016-07-15), p. 2540-2540
    Kurzfassung: Background: Sporadic cancer formation from stem cells, and molecular switches leading to this remain poorly understood. Beckwith-Wiedemann syndrome (BWS) is a human stem cell disorder with an 800-fold increased risk of developing tumors. Imprinting of the IGF2/H19 and the CDKN1C/KCNQ1 loci on chromosome 11p15.5 is mediated by the chromatin insulator CCCTC-binding factor (CTCF). This regulation is lost in BWS, leading to aberrant overexpression of the growth promoting genes. Epigenetic silencing of β2-spectrin (β2SP, gene SPTBN1), a SMAD adaptor for Transforming Growth Factor-beta (TGF-β) signaling, is causally associated with BWS. With this new model for BWS, the mechanisms though which disruption of TGF-β signaling leads to tumorigenesis could be elucidated further. We further sought to determine the roles of the TGF-β-mediated β2SP/SMAD3/CTCF complex in stem cell biological function. Experimental procedures: 1. Tumorigenesis analysis in Sptbn1+/− /Smad3+/− mice. 2. Whole-transcriptome sequencing were performed in the BWS cells and Sptbn1+/−; Sptbn1−/−; Smad3+/−; and Sptbn1+/−/Smad3+/− MEFs. 3. Tumor-initiating-cell (TIC) tumorigenesis, sphere formation assays were performed for stem cell like characteristics. Results: 1. We observed that double heterozygous Sptbn1+/−/Smad3+/− mice with defective TGF-β signaling develop multiple tumors phenotypically similar to those of BWS. 2. CTCF is TGF-β-inducible and facilitates TGF-β-mediated repression of hTERT transcription via β2SP/SMAD3/CTCF interactions. This regulation is abrogated in the TGF-β defective mice and BWS, causing hTERT overexpression. 3. Whole-transcriptome RNA sequencing of MEFs isolated from these three TGF-β-deficient strains displayed increased levels of stem cell-associated genes, including PDPN, EPAS1, CXCL1 and ALDH2. 4. CTCF, β2SP, and SMAD3, and modulate stem cell like characteristics such as CD133+/CD49+ TIC tumorigenesis, sphere formation and nanog expression. 5. Further, knock-down of β2SP, Smad3, or CTCF in HepG2 cells resulted in an increase of sphere formation, further supporting a role of these elements in regulating stemness. Conclusions: Loss of CTCF-dependent imprinting of tumor promoter genes such as IGF2 and TERT is caused by a defective TGF-β pathway, giving new insight into BWS-associated tumorigenesis and sporadic human cancers that are associated with mutations in SPTBN1 and SMAD3. Dysfunction of the β2SP/SMAD3/CTCF complex increases stem-like properties and enhances TICs. Our analysis provides important insight into the switches involved in sporadic cancer formation, particularly those associated with this human stem cell disorder. Citation Format: Jian Chen, Zhixing Yao, Jiun-Sheng Chen, Young Jin Gi, Yun Seong Jeong, Wilma Jogunoori, Mitchell Belkin, Bibhuti Mishra, Jon White, Abhisek Mitra, Shulin Li, Milton Finegold, Marta Davila, Jerry Shay, Keigo Machida, Hidekazu Tsukamoto, Lopa Mishra. Disruption of a TGF-β-CTCF regulated pathway leads to cancer stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2540.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2016
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
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