scholarly journals HIC1 and RassF1A Methylation Attenuates Tubulin Expression and Cell Stiffness in Cancer

2018 ◽  
Vol 19 (10) ◽  
pp. 2884 ◽  
Author(s):  
Chih-Cheng Chen ◽  
Bo-Ching He ◽  
Yao-Li Chen ◽  
Kuan-Der Lee ◽  
Chun-Hsin Tung ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cultured Cells ◽  
Cell Transformation ◽  
Tumor Development ◽  
Cellular Transformation ◽  
Cell Stiffness ◽  
Physiological Status ◽  
Rassf1a Methylation ◽  
Potential Biomarker

Cell stiffness is a potential biomarker for monitoring cellular transformation, metastasis, and drug resistance development. Environmental factors relayed into the cell may result in formation of inheritable markers (e.g., DNA methylation), which provide selectable advantages (e.g., tumor development-favoring changes in cell stiffness). We previously demonstrated that targeted methylation of two tumor suppressor genes, hypermethylated in cancer 1 (HIC1) and Ras-association domain family member 1A (RassF1A), transformed mesenchymal stem cells (MSCs). Here, transformation-associated cytoskeleton and cell stiffness changes were evaluated. Atomic force microscopy (AFM) was used to detect cell stiffness, and immunostaining was used to measure cytoskeleton expression and distribution in cultured cells as well as in vivo. HIC1 and RassF1A methylation (me_HR)-transformed MSCs developed into tumors that clonally expanded in vivo. In me_HR-transformed MSCs, cell stiffness was lost, tubulin expression decreased, and F-actin was disorganized; DNA methylation inhibitor treatment suppressed their tumor progression, but did not fully restore their F-actin organization and stiffness. Thus, me_HR-induced cell transformation was accompanied by the loss of cellular stiffness, suggesting that somatic epigenetic changes provide inheritable selection markers during tumor propagation, but inhibition of oncogenic aberrant DNA methylation cannot restore cellular stiffness fully. Therefore, cell stiffness is a candidate biomarker for cells’ physiological status.

TMOD-02. GENERATION OF A NOVEL MOUSE MODEL FOR BRAIN TUMORS OF THE DNA METHYLATION CLASS “GBM MYCN”

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi215-vi216
Author(s):  
Melanie Schoof ◽  
Carolin Göbel ◽  
Dörthe Holdhof ◽  
Sina Al-Kershi ◽  
Ulrich Schüller
Keyword(s):  
Dna Methylation ◽  
Brain Tumors ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Tumor Development ◽  
Model Systems ◽  
Preclinical Research ◽  
Human Gbm

Abstract DNA methylation based classification of brain tumors has revealed a high heterogeneity between tumors and led to the description of multiple distinct subclasses. The increasing subdivision of tumors can help to understand molecular mechanisms of tumor development and to improve therapy if appropriate model systems for preclinical research are available. Multiple recent publications have described a subgroup of pediatric glioblastoma which is clearly separable from other pediatric and adult glioblastoma in its DNA methylation profile (GBM MYCN). Many cases in this group are driven by MYCN amplifications and harbor TP53 mutations. These tumors almost exclusively occur in children and were further described as highly aggressive with a median overall survival of only 14 months. In order to further investigate the biology and treatment options of these tumors, we generated hGFAP-cre::TP53 Fl/Fl ::lsl-MYCN mice. These mice carry a loss of TP53 and show aberrant MYCN expression in neural precursors of the central nervous system. The animals develop large forebrain tumors within the first 80 days of life with 100 % penetrance. These tumors resemble human GBM MYCN tumors histologically and are sensitive to AURKA and ATR inhibitors in vitro. We believe that further characterization of the model and in vivo treatment studies will pave the way to improve treatment of patients with these highly aggressive tumors.

scholarly journals DNA methylation specifies chromosomal localization of MeCP2.

1996 ◽  
Vol 16 (1) ◽  
pp. 414-421 ◽  
Author(s):  
X Nan ◽  
P Tate ◽  
E Li ◽  
A Bird
Keyword(s):  
Dna Methylation ◽  
Cultured Cells ◽  
Centromeric Heterochromatin ◽  
Intact Protein ◽  
Chromosomal Protein ◽  
Mouse Cells ◽  
Low Levels ◽  
Mutant Cells

MeCP2 is a chromosomal protein that is concentrated in the centromeric heterochromatin of mouse cells. In vitro, the protein binds preferentially to DNA containing a single symmetrically methylated CpG. To find out whether the heterochromatic localization of MeCP2 depended on DNA methylation, we transiently expressed MeCP2-LacZ fusion proteins in cultured cells. Intact protein was targeted to heterochromatin in wild-type cells but was inefficiently localized in mutant cells with low levels of genomic DNA methylation. Deletions within MeCP2 showed that localization to heterochromatin required the 85-amino-acid methyl-CpG binding domain but not the remainder of the protein. Thus MeCP2 is a methyl-CpG-binding protein in vivo and is likely to be a major mediator of downstream consequences of DNA methylation.

scholarly journals MiR-223 Promotes Tumor Progression via Targeting RhoB in Gastric Cancer

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
You Hu ◽  
Bin Yi ◽  
Xin Chen ◽  
Lu Xu ◽  
Xiaojun Zhou ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Progression ◽  
Cancer Progression ◽  
Tumor Development ◽  
Migration And Invasion ◽  
Cellular Mechanisms ◽  
Borrmann Type ◽  
Potential Biomarker

Gastric cancer (GC) is among the most prevalent causes of cancer-related death globally. MiR-223 has been implicated in a variety of cellular mechanisms linked to cancer progression. However, the miR-223 expressions and its function in GC are unknown. We discovered that miR-223 expression was raised in GC tissues in comparison with nearby normal tissues in this investigation. Additionally, multiplied miR-223 expression was strongly linked with TNM stage ( p = 0.022 ), live metastasis ( p = 0.004 ),lymph node metastasis ( p = 0.004 ),and Borrmann type and was associated with an unfavorable prognostic for patients with GC. Furthermore, suppressing miR-223 significantly increased cell death and prevented cell migration and invasion in vitro. Additionally, miR-223 silencing decreased tumor development in vivo. Additionally, we discovered that miR-223 enhanced GC development by specifically targeting RhoB. In summary, our findings reveal that miR-223 increases tumor progression in GC by targeting RhoB, suggesting that it could serve to be a potential biomarker for the prediction of the disease.

scholarly journals Kras activation in endometrial organoids drives cellular transformation and epithelial-mesenchymal transition

Oncogenesis ◽  
2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Yoshiaki Maru ◽  
Naotake Tanaka ◽  
Yasutoshi Tatsumi ◽  
Yuki Nakamura ◽  
Makiko Itami ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Epithelial Mesenchymal Transition ◽  
Tumor Development ◽  
Cellular Transformation ◽  
In Vivo Models ◽  
Mesenchymal Transition ◽  
Endometrial Cells ◽  
Immunodeficient Mice ◽  
Organ Type

AbstractKRAS, an oncogene, is frequently activated by mutations in many cancers. Kras-driven adenocarcinoma development in the lung, pancreas, and biliary tract has been extensively studied using gene targeting in mice. By taking the organoid- and allograft-based genetic approach to these organs, essentially the same results as in vivo models were obtained in terms of tumor development. To verify the applicability of this approach to other organs, we investigated whether the combination of Kras activation and Pten inactivation, which gives rise to endometrial tumors in mice, could transform murine endometrial organoids in the subcutis of immunodeficient mice. We found that in KrasG12D-expressing endometrial organoids, Pten knockdown did not confer tumorigenicity, but Cdkn2a knockdown or Trp53 deletion led to the development of carcinosarcoma (CS), a rare, aggressive tumor comprising both carcinoma and sarcoma. Although they originated from epithelial cells, some CS cells expressed both epithelial and mesenchymal markers. Upon inoculation in immunodeficient mice, tumor-derived round organoids developed carcinoma or CS, whereas spindle-shaped organoids formed monophasic sarcoma only, suggesting an irreversible epithelial-mesenchymal transition during the transformation of endometrial cells and progression. As commonly observed in mutant Kras-driven tumors, the deletion of the wild-type Kras allele was identified in most induced tumors, whereas some epithelial cells in CS-derived organoids were unexpectedly negative for KrasG12D. Collectively, we showed that the oncogenic potential of KrasG12D and the histological features of derived tumors are context-dependent and varies according to the organ type and experimental settings. Our findings provide novel insights into the mechanisms underlying tissue-specific Kras-driven tumorigenesis.

scholarly journals Real-Time Monitoring of Nuclear Factor κB Activity in Cultured Cells and in Animal Models

2009 ◽  
Vol 8 (5) ◽  
pp. 7290.2009.00026 ◽  
Author(s):  
Christian E. Badr ◽  
Johanna M. Niers ◽  
Lee-Ann Tjon-Kon-Fat ◽  
David P. Noske ◽  
Thomas Wurdinger ◽  
...  
Keyword(s):  
Real Time ◽  
Cultured Cells ◽  
Tumor Development ◽  
Nuclear Factor Κb ◽  
Tumor Formation ◽  
Nuclear Factor ◽  
Reporter System ◽  
Human Disorders

Nuclear factor κB (NF-κB) is a transcription factor that plays a major role in many human disorders, including immune diseases and cancer. We designed a reporter system based on NF-κB responsive promoter elements driving expression of the secreted Gaussia princeps luciferase (Gluc). We show that this bioluminescent reporter is a highly sensitive tool for noninvasive monitoring of the kinetics of NF-κB activation and inhibition over time, both in conditioned medium of cultured cells and in the blood and urine of animals. NF-κB activation was successfully monitored in real time in endothelial cells in response to tumor angiogenic signaling, as well as in monocytes in response to inflammation. Further, we demonstrated dual blood monitoring of both NF-κB activation during tumor development as correlated to tumor formation using the NF-κB Gluc reporter, as well as the secreted alkaline phosphatase reporter. This NF-κB reporter system provides a powerful tool for monitoring NF-κB activity in real time in vitro and in vivo.

scholarly journals The trans fatty acid elaidate affects the global DNA methylation profile of cultured cells and in vivo

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
José Flores-Sierra ◽  
Martín Arredondo-Guerrero ◽  
Braulio Cervantes-Paz ◽  
Dalia Rodríguez-Ríos ◽  
Yolanda Alvarado-Caudillo ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Fatty Acid ◽  
Trans Fatty Acid ◽  
Cultured Cells ◽  
Methylation Profile ◽  
Global Dna Methylation ◽  
Dna Methylation Profile

scholarly journals A Mechanistic Investigation of the Relationship Between Extramural Vascular Invasion (EMVI) and CpG Island Methylator Phenotype (CIMP) in Rectal Cancer

2021 ◽  
Author(s):  
◽  
Rory Kokelaar
Keyword(s):  
Colorectal Cancer ◽  
Dna Methylation ◽  
Rectal Cancer ◽  
Vascular Invasion ◽  
Survival Outcomes ◽  
Potential Biomarker ◽  
Mechanistic Investigation ◽  
Rectal Cancers

Colorectal cancer (CRC) is the third most frequent cancer and the second leading cause of cancer death worldwide. Each year, one million people will develop CRC, and 40-50% will die within five years. Furthermore, rectal and distal sigmoid cancers are known to present at a later stage and have a poorer prognosis than other colonic cancers. Rectal cancers that demonstrate pathological extramural vascular invasion (EMVI-positive) are known to have a poorer prognosis than those that do not (EMIV-negative), and EMVI has is acknowledged as an important risk factor for systemic recurrence, local recurrence and death. Additionally, EMVI status influences the need for pre- and post-operative chemoradiation (CRT); which may influence survival outcomes. Aberrant DNA methylation is emerging as a carcinogenic mechanism and potential biomarker in colorectal cancer. This study investigates the association between hypermethylation and EMVI in vivo and in vitro. Firstly, the in vivo associations between hypermethylation, EMVI, and clinical and histopathological outcomes are examined. Secondly, an investigation of the effects of demethylation on invasive colorectal cell lines in vitro aims to illuminate the genetic and cellular mechanisms that underlie methylation-dependent pathological cellular behaviour. Finally, highlighted biologic mechanisms are investigated in vivo to discover if there is an association with EMVI and survival outcomes. By these means the axis of association between hypermethylation, EMVI, and clinical outcomes is investigated. The investigation is conducted within the framework of consensus molecular subtyping in colorectal cancer, and in concordance with current methodologies of assessing DNA methylation status. The primary findings demonstrate that EMVI is associated with hypermethylation in vivo, but that there is no direct correlation between hypermethylation and disease-free (DFS) or overall survival (OS). In vitro, demethylation of hypermethylated colorectal cancer cells, by means of established demethylating agent 5-azacytidine and putative demethylator RRx-001, reduces their propensity to migrate and invade. Demethylation in vitro is also associated with changes in the expression of the metalloproteinases involved in the metabolism of the basement membrane and the epithelial-to-mesenchymal transition and tumour metastasis, notably MMP2 and TIMP2. Changes in expression were confirmed at transcriptomal and proteomic levels in response to demethylation. In vivo, MMP2 expression was shown to be statistically significantly associated with EMVI, DFS, and OS, and was also independently predictive of EMVI, raising the possibility that it could act as a diagnostic and predictive biomarker in rectal cancers. These findings indicate a mechanistic association between hypermethylation and EMVI, mediated by methylation-dependent expression of metalloproteinases. Metalloproteinase expression, specifically MMP2, may act as a potential biomarker for EMVI and correlates to survival outcomes in rectal cancer.

scholarly journals Aurora B Overexpression Causes Aneuploidy and p21Cip1Repression during Tumor Development

2015 ◽  
Vol 35 (20) ◽  
pp. 3566-3578 ◽  
Author(s):  
Alejandra González-Loyola ◽  
Gonzalo Fernández-Miranda ◽  
Marianna Trakala ◽  
David Partida ◽  
Kumiko Samejima ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Cultured Cells ◽  
Tumor Development ◽  
Inverse Correlation ◽  
Aurora Kinase ◽  
Tumor Formation ◽  
Aurora B ◽  
Aurora Kinase B

Aurora kinase B, one of the three members of the mammalian Aurora kinase family, is the catalytic component of the chromosomal passenger complex, an essential regulator of chromosome segregation in mitosis. Aurora B is overexpressed in human tumors although whether this kinase may function as an oncogenein vivois not established. Here, we report a new mouse model in which expression of the endogenousAurkblocus can be inducedin vitroandin vivo. Overexpression of Aurora B in cultured cells induces defective chromosome segregation and aneuploidy. Long-term overexpression of Aurora Bin vivoresults in aneuploidy and the development of multiple spontaneous tumors in adult mice, including a high incidence of lymphomas. Overexpression of Aurora B also results in a reduced DNA damage response and decreased levels of the p53 target p21Cip1in vitroandin vivo, in line with an inverse correlation between Aurora B and p21Cip1expression in human leukemias. Thus, overexpression of Aurora B may contribute to tumor formation not only by inducing chromosomal instability but also by suppressing the function of the cell cycle inhibitor p21Cip1.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

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