FTO Demethylates Cyclin D1 mRNA and Controls Cell-Cycle Progression

ABSTRACT Novel techniques were used to determine when in the cell cycle of proliferating NIH 3T3 cells cellular Ras and cyclin D1 are required. For comparison, in quiescent cells, all four of the inhibitors of cell cycle progression tested (anti-Ras, anti-cyclin D1, serum removal, and cycloheximide) became ineffective at essentially the same point in G1 phase, approximately 4 h prior to the beginning of DNA synthesis. To extend these studies to cycling cells, a time-lapse approach was used to determine the approximate cell cycle position of individual cells in an asynchronous culture at the time of inhibitor treatment and then to determine the effects of the inhibitor upon recipient cells. With this approach, anti-Ras antibody efficiently inhibited entry into S phase only when introduced into cells prior to the preceding mitosis, several hours before the beginning of S phase. Anti-cyclin D1, on the other hand, was an efficient inhibitor when introduced up until just before the initiation of DNA synthesis. Cycloheximide treatment, like anti-cyclin D1 microinjection, was inhibitory throughout G1 phase (which lasts a total of 4 to 5 h in these cells). Finally, serum removal blocked entry into S phase only during the first hour following mitosis. Kinetic analysis and a novel dual-labeling technique were used to confirm the differences in cell cycle requirements for Ras, cyclin D1, and cycloheximide. These studies demonstrate a fundamental difference in mitogenic signal transduction between quiescent and cycling NIH 3T3 cells and reveal a sequence of signaling events required for cell cycle progression in proliferating NIH 3T3 cells.

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MiR-15b Targets Cyclin D1 to Regulate Proliferation and Apoptosis in Glioma Cells

BioMed Research International ◽

10.1155/2014/687826 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 29

Author(s):

Guan Sun ◽

Lei Shi ◽

Shushan Yan ◽

Zhengqiang Wan ◽

Nan Jiang ◽

...

Keyword(s):

Cell Cycle ◽

Cyclin D1 ◽

Cell Cycle Progression ◽

Therapeutic Strategy ◽

Glioma Cells ◽

Luciferase Assay ◽

Luciferase Reporter ◽

Cycle Progression ◽

Cycle Arrest ◽

Proliferation And Apoptosis

Aim. To investigate the role and mechanism of miR-15b in the proliferation and apoptosis of glioma.Methods. The miR-15b mimics were transfected into human glioma cells to upregulate the miR-15b expression. Cyclin D1 was determined by both western blotting analysis and luciferase reporter assay. Methylthiazol tetrazolium (MTT) and flow cytometry were employed to detect the cell proliferation, cell cycle, and apoptosis.Results. Overexpression of miR-15b inhibits proliferation by arrested cell cycle progression and induces apoptosis, possibly by directly targeting Cyclin D1. Both luciferase assay and bioinformatics search revealed a putative target site of miR-15b binding to the 3′-UTR of Cyclin D1. Moreover, expression of miR-15b in glioma tissues was found to be inversely correlated with Cyclin D1 expression. Enforced Cyclin D1 could abrogate the miR-15b-mediated cell cycle arrest and apoptosis.Conclusions. Our findings identified that miR-15b may function as a glioma suppressor by targeting the Cyclin D1, which may provide a novel therapeutic strategy for treatment of glioma.

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Growth factor, steroid, and steroid antagonist regulation of cyclin gene expression associated with changes in T-47D human breast cancer cell cycle progression.

Molecular and Cellular Biology ◽

10.1128/mcb.13.6.3577 ◽

1993 ◽

Vol 13 (6) ◽

pp. 3577-3587 ◽

Cited By ~ 197

Author(s):

E A Musgrove ◽

J A Hamilton ◽

C S Lee ◽

K J Sweeney ◽

C K Watts ◽

...

Keyword(s):

Breast Cancer ◽

Gene Expression ◽

Cell Cycle ◽

Cyclin D1 ◽

Cancer Cell ◽

Breast Cancer Cell ◽

Cell Cycle Progression ◽

S Phase ◽

G1 Phase ◽

Cycle Progression

Cyclins and proto-oncogenes including c-myc have been implicated in eukaryotic cell cycle control. The role of cyclins in steroidal regulation of cell proliferation is unknown, but a role for c-myc has been suggested. This study investigated the relationship between regulation of T-47D breast cancer cell cycle progression, particularly by steroids and their antagonists, and changes in the levels of expression of these genes. Sequential induction of cyclins D1 (early G1 phase), D3, E, A (late G1-early S phase), and B1 (G2 phase) was observed following insulin stimulation of cell cycle progression in serum-free medium. Transient acceleration of G1-phase cells by progestin was also accompanied by rapid induction of cyclin D1, apparent within 2 h. This early induction of cyclin D1 and the ability of delayed administration of antiprogestin to antagonize progestin-induced increases in both cyclin D1 mRNA and the proportion of cells in S phase support a central role for cyclin D1 in mediating the mitogenic response in T-47D cells. Compatible with this hypothesis, antiestrogen treatment reduced the expression of cyclin D1 approximately 8 h before changes in cell cycle phase distribution accompanying growth inhibition. In the absence of progestin, antiprogestin treatment inhibited T-47D cell cycle progression but in contrast did not decrease cyclin D1 expression. Thus, changes in cyclin D1 gene expression are often, but not invariably, associated with changes in the rate of T-47D breast cancer cell cycle progression. However, both antiestrogen and antiprogestin depleted c-myc mRNA by > 80% within 2 h. These data suggest the involvement of both cyclin D1 and c-myc in the steroidal control of breast cancer cell cycle progression.

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Regulation of cyclin D1 expression and cell cycle progression by mitogen-activated protein kinase cascade

Kidney International ◽

10.1046/j.1523-1755.1999.00704.x ◽

1999 ◽

Vol 56 (4) ◽

pp. 1258-1261 ◽

Cited By ~ 38

Author(s):

Yoshio Terada ◽

Seiji Inoshita ◽

Osamu Nakashima ◽

Michio Kuwahara ◽

Sei Sasaki ◽

...

Keyword(s):

Cell Cycle ◽

Protein Kinase ◽

Cyclin D1 ◽

Cell Cycle Progression ◽

Mitogen Activated Protein Kinase ◽

Cycle Progression ◽

Mitogen Activated Protein ◽

Kinase Cascade ◽

Protein Kinase Cascade

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Cell Cycle Arrest and Reversion of Ras-Induced Transformation by a Conditionally Activated Form of Mitogen-Activated Protein Kinase Kinase Kinase 3

Molecular and Cellular Biology ◽

10.1128/mcb.19.5.3857 ◽

1999 ◽

Vol 19 (5) ◽

pp. 3857-3868 ◽

Cited By ~ 57

Author(s):

Heidrun Ellinger-Ziegelbauer ◽

Kathleen Kelly ◽

Ulrich Siebenlist

Keyword(s):

Cell Cycle ◽

Protein Kinase ◽

Cyclin D1 ◽

Stress Responses ◽

Cell Cycle Progression ◽

Cellular Transformation ◽

Mitogen Activated Protein Kinase ◽

Cycle Progression ◽

Mapk Kinase ◽

Mitogen Activated Protein

ABSTRACT Signal-induced proliferation, differentiation, or stress responses of cells depend on mitogen-activated protein kinase (MAPK) cascades, the core modules of which consist of members of three successively acting kinase families (MAPK kinase kinase [MAP3K], MAPK kinase, and MAPK). It is demonstrated here that the MEKK3 kinase inhibits cell proliferation, a biologic response not commonly associated with members of the MAP3K family of kinases. A conditionally activated form of MEKK3 stably expressed in fibroblasts arrests these cells in early G1. MEKK3 critically blocks mitogen-driven expression of cyclin D1, a cyclin which is essential for progression of fibroblasts through G1. The MEKK3-induced block of cyclin D1 expression and of cell cycle progression may be mediated via p38 MAPK, a downstream effector of MEKK3. The MEKK3-mediated block of proliferation also reverses Ras-induced cellular transformation, suggesting possible tumor-suppressing functions for this kinase. Together, these results suggest an involvement of the MEKK3 kinase in negative regulation of cell cycle progression, and they provide the first insights into biologic activities of this kinase.

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Truncation in CCND1 mRNA 3′ UTR Is Associated with An Aggressive Phenotype and Chemoresistance

Blood ◽

10.1182/blood.v112.11.5287.5287 ◽

2008 ◽

Vol 112 (11) ◽

pp. 5287-5287

Author(s):

Robert W Chen ◽

Myo Htut ◽

Britta Hoehn ◽

Eamon Berge ◽

William Robinson ◽

...

Keyword(s):

Cell Cycle ◽

Protein Expression ◽

Cyclin D1 ◽

Cell Lines ◽

Cell Cycle Progression ◽

Serum Starvation ◽

Cycle Progression ◽

Serum Free ◽

Aggressive Phenotype ◽

Free Media

Abstract Mantle Cell Lymphoma (MCL) represents 5–10% of all non-Hodgkins lymphomas, making it an uncommon but difficult form of lymphoma to treat. It has the worst prognosis among the B cell lymphomas with median survival of three years. The genetic hallmark of MCL is the t(11,14)(q13;32) translocation causing amplification of cyclin D1 (CCND1). It is a well known cell cycle regulator. Multiple reports have shown a truncation in the cyclin D1 mRNA 3′ untranslated region. This truncation increases CCND1 protein expression by not only enhancing the half-life of CCND1 mRNA, but also evades microRNA regulation of mRNA translation. The dramatic overexpression of CCND1 mRNA and protein has been associated to poor clinical outcome in patients. We hypothesize that this truncation leads to a more aggressive phenotype and induces chemoresistance in MCL. We have identified 4 MCL cell lines (Granta-519, JVM-2, Jeko-1, and Z138) with different levels of the truncated CCND1 mRNA. We were able to show that Z138 and Jeko-1 have a much higher ratio of truncated CCND1 mRNA to the full length CCND1 mRNA as compared to Granta-519 and JVM-2. We were also able to show that this truncated mRNA leads to an increase in CCND1 protein expression. By using flow cytometry, we correlated the increase in CCND1 protein expression to faster cell cycle progression. We proposed that cell lines with increased CCND1 expression are phenotypically more aggressive, and would be able to continue cell cycle progression without serum support. We were able to arrest JVM-2 in G1 phase after 48 hours of serum starvation. However, we were not able to arrest cell cycle progression in Jeko-1 even after 96 hours of serum starvation. Western blot analysis shows that CCND1 protein expression is decreased in JVM-2 but remains unchanged in Jeko-1 with serum starvation. The same phenomenon was observed in Granta-519 and Z138. The MCL cell lines (Jeko-1 and Z-138) with more CCND1 protein expression were able to continue cell cycle progression in serum free media. The MCL cell lines (JVM-2 and Granta-519) with less CCND1 protein expression were not able to continue cell cycle progression in serum free media. This shows that CCND1 overexpression is associated with a more aggressive phenotype. We then treated the 4 MCL cell lines with varying concentrations of doxorubicin, a standard anthracycline chemotherapy used in the treatment of MCL patients. We used MTS assay to assess cell proliferation after treatment with doxorubicin. We found the IC 50 (inhibitory concentration 50%) of doxorubicin in these cell lines varied from 6nM to 600nM. The cell lines (Jeko-1 and Z-138) with more CCND1 protein expression have a much higher IC 50 as compared to the cell lines (JVM-2 and Granta-519) with less CCND1 protein expression. This demonstrates that CCND1 overexpression is associated with chemoresistance. We conclude truncation in CCND1 mRNA leads to increased CCND1 protein expression and faster cell cycle progression CCND1 overexpression is associated with an aggressive phenotype CCND1 overexpression is associated with chemoresistance.

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