Global transcriptional program of p53 target genes during the process of apoptosis and cell cycle progression

AbstractGrainyhead-like 1 (GRHL1) is a transcription factor involved in embryonic development. However, little is known about the biological functions of GRHL1 in cancer. In this study, we found that GRHL1 was upregulated in non-small cell lung cancer (NSCLC) and correlated with poor survival of patients. GRHL1 overexpression promoted the proliferation of NSCLC cells and knocking down GRHL1 inhibited the proliferation. RNA sequencing showed that a series of cell cycle-related genes were altered when knocking down GRHL1. We further demonstrated that GRHL1 could regulate the expression of cell cycle-related genes by binding to the promoter regions and increasing the transcription of the target genes. Besides, we also found that EGF stimulation could activate GRHL1 and promoted its nuclear translocation. We identified the key phosphorylation site at Ser76 on GRHL1 that is regulated by the EGFR-ERK axis. Taken together, these findings elucidate a new function of GRHL1 on regulating the cell cycle progression and point out the potential role of GRHL1 as a drug target in NSCLC.

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The RASSF6 Tumor Suppressor Protein Regulates Apoptosis and Cell Cycle Progression via Retinoblastoma Protein

Molecular and Cellular Biology ◽

10.1128/mcb.00046-18 ◽

2018 ◽

Vol 38 (17) ◽

Cited By ~ 2

Author(s):

Shakhawoat Hossain ◽

Hiroaki Iwasa ◽

Aradhan Sarkar ◽

Junichi Maruyama ◽

Kyoko Arimoto-Matsuzaki ◽

...

Keyword(s):

Cell Cycle ◽

Tumor Suppressor ◽

Cell Cycle Arrest ◽

Cell Cycle Progression ◽

Target Genes ◽

Loss Of Function ◽

Cycle Progression ◽

P53 Expression ◽

Cycle Arrest ◽

Hct116 Cells

ABSTRACT RASSF6 is a member of the tumor suppressor Ras association domain family (RASSF) proteins. RASSF6 is frequently suppressed in human cancers, and its low expression level is associated with poor prognosis. RASSF6 regulates cell cycle arrest and apoptosis and plays a tumor suppressor role. Mechanistically, RASSF6 blocks MDM2-mediated p53 degradation and enhances p53 expression. However, RASSF6 also induces cell cycle arrest and apoptosis in a p53-negative background, which implies that the tumor suppressor function of RASSF6 does not depend solely on p53. In this study, we revealed that RASSF6 mediates cell cycle arrest and apoptosis via pRb. RASSF6 enhances the interaction between pRb and protein phosphatase. RASSF6 also enhances P16INK4A and P14ARF expression by suppressing BMI1. In this way, RASSF6 increases unphosphorylated pRb and augments the interaction between pRb and E2F1. Moreover, RASSF6 induces TP73 target genes via pRb and E2F1 in a p53-negative background. Finally, we confirmed that RASSF6 depletion induces polyploid cells in p53-negative HCT116 cells. In conclusion, RASSF6 behaves as a tumor suppressor in cancers with loss of function of p53, and pRb is implicated in this function of RASSF6.

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Abstract 4774: JC virus T-antigen-dependent activation of Wnt target genes and cell cycle progression in colon cancer.

10.1158/1538-7445.am2013-4774 ◽

2013 ◽

Author(s):

Michael J. Ripple ◽

Amanda Struckhoff ◽

Robin McGoey ◽

Luis Del Valle

Keyword(s):

Cell Cycle ◽

Colon Cancer ◽

Cell Cycle Progression ◽

Target Genes ◽

Jc Virus ◽

T Antigen ◽

Cycle Progression

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Lamina-associated polypeptide 2α regulates cell cycle progression and differentiation via the retinoblastoma–E2F pathway

The Journal of Cell Biology ◽

10.1083/jcb.200511149 ◽

2006 ◽

Vol 173 (1) ◽

pp. 83-93 ◽

Cited By ~ 98

Author(s):

Daniela Dorner ◽

Sylvia Vlcek ◽

Nicole Foeger ◽

Andreas Gajewski ◽

Christian Makolm ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Target Genes ◽

Serum Starvation ◽

Dependent Manner ◽

Cycle Progression ◽

Promoter Sequences ◽

Delayed Entry ◽

Accelerated Proliferation

Lamina-associated polypeptide (LAP) 2α is a nonmembrane-bound LAP2 isoform that forms complexes with nucleoplasmic A-type lamins. In this study, we show that the overexpression of LAP2α in fibroblasts reduced proliferation and delayed entry into the cell cycle from a G0 arrest. In contrast, stable down-regulation of LAP2α by RNA interference accelerated proliferation and interfered with cell cycle exit upon serum starvation. The LAP2α-linked cell cycle phenotype is mediated by the retinoblastoma (Rb) protein because the LAP2α COOH terminus directly bound Rb, and overexpressed LAP2α inhibited E2F/Rb-dependent reporter gene activity in G1 phase in an Rb-dependent manner. Furthermore, LAP2α associated with promoter sequences in endogenous E2F/Rb-dependent target genes in vivo and negatively affected their expression. In addition, the expression of LAP2α in proliferating preadipocytes caused the accumulation of hypophosphorylated Rb, which is reminiscent of noncycling cells, and initiated partial differentiation into adipocytes. The effects of LAP2α on cell cycle progression and differentiation may be highly relevant for the cell- and tissue-specific phenotypes observed in laminopathic diseases.

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The RASSF6 tumor suppressor protein regulates apoptosis and the cell cycle progression via Retinoblastoma protein

10.1101/334276 ◽

2018 ◽

Author(s):

Shakhawoat Hossain ◽

Hiroaki Iwasa ◽

Aradhan Sarkar ◽

Junichi Maruyama ◽

Kyoko Arimoto-Matsuzaki ◽

...

Keyword(s):

Cell Cycle ◽

Tumor Suppressor ◽

Cell Cycle Arrest ◽

Cell Cycle Progression ◽

Target Genes ◽

Loss Of Function ◽

Cycle Progression ◽

P53 Expression ◽

Cycle Arrest ◽

Hct116 Cells

ABSTRACTRASSF6 is a member of the tumor suppressor Ras-association domain family (RASSF) proteins. RASSF6 is frequently suppressed in human cancers and its low expression is associated with poor prognosis. RASSF6 regulates cell cycle arrest and apoptosis and plays a tumor suppressor role. Mechanistically, RASSF6 blocks MDM2-mediated p53 degradation and enhances p53 expression. However, RASSF6 also induces cell cycle arrest and apoptosis in the p53-negative background, which implies that the tumor suppressor function of RASSF6 does not depend solely on p53. In this study, we have revealed that RASSF6 mediates cell cycle arrest and apoptosis via pRb. RASSF6 enhances the interaction between pRb and protein phosphatase. RASSF6 also enhances P16INK4A and P14ARF expression through suppressing BMI1. In this way, RASSF6 increases unphosphorylated pRb and augments the interaction between pRb and E2F1. Moreover, RASSF6 induces TP73-target genes via pRb and E2F1 in the p53-negative background. Finally, we confirmed that RASSF6 depletion induces polypoid cells in p53-negative HCT116 cells. In conclusion, RASSF6 behaves as a tumor suppressor in cancers with the loss-of-function of p53, and pRb is implicated in this function of RASSF6.

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CREB Regulates Cell Cycle Progression through RFC3-PCNA Axis in Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v124.21.881.881 ◽

2014 ◽

Vol 124 (21) ◽

pp. 881-881

Author(s):

Hee-Don Chae ◽

Bryan Mitton ◽

Kathleen Sakamoto

Keyword(s):

Cell Cycle ◽

Acute Myeloid Leukemia ◽

Promoter Region ◽

Myeloid Leukemia ◽

Cell Cycle Progression ◽

Target Genes ◽

Conflicts Of Interest ◽

Nuclear Antigen ◽

Cycle Progression ◽

Acute Myeloid

Abstract CREB (cAMP Response Element Binding protein) is a transcription factor overexpressed in normal and neoplastic myelopoiesis and regulates cell cycle progression, although its oncogenic mechanism has not been well characterized. Replication Factor C3 (RFC3), a 38 kDa subunit of the RFC complex, is required for chromatin loading of proliferating cell nuclear antigen (PCNA) which is a sliding clamp platform for recruiting numerous proteins in DNA replication and repair processes. CREB1 expression was coupled with RFC3 expression during the G1/S progression in the KG-1 acute myeloid leukemia (AML) cell line, suggesting that RFC3 and CREB1 might be target genes of E2F, a key transcriptional regulator of the G1/S progression. Though there were two potential E2F binding sites in the RFC3 promoter region, chromatin immunoprecipitation assays provided no evidence for E2F1 binding to the RFC3 promoter, whereas E2F1 could directly act on the CREB1 expression. Treatment with the cyclin-dependent kinase (CDK) inhibitor AT7519 decreased expression of CREB1 and RFC3 as well as well-known E2F target genes such as CCNE1, CCNA2 and CCNB1 in KG-1 cells. These results indicate that CREB1 overexpression, a potentially important prognostic marker in leukemia patients, may be associated with dysregulated CDK-E2F activity in leukemia. There was also a direct correlation between the expression of RFC3 and CREB1 in human AML cell lines as well as in AML cells from patients. CREB interacted directly with the CRE site in RFC3 promoter region. CREB knockdown primarily inhibited G1/S cell cycle transition, decreasing expression of RFC3 as well as PCNA loading onto chromatin. Exogenous expression of RFC3 was sufficient to rescue the impaired G1/S progression and PCNA chromatin loading [Chromatin-bound PCNA-positive cells (%), control vs. CREB-knockdown vs. CREB-knockdown with RFC3 overexpression, 8h after release from mitotic arrest: 66.87 +/– 0.90 vs. 24.77 +/– 0.99 vs. 79.17 +/– 0.12, n=3, p< 0.01, mean +/– SEM] caused by CREB knockdown. Taken together, our results suggest that RFC3 may play a role in neoplastic myelopoiesis by promoting the G1/S progression, and its expression is regulated by CREB. These data provide new insight into CREB-driven regulation of the cell cycle in AML cells, and may contribute to leukemogenesis associated with CREB overexpression. Disclosures No relevant conflicts of interest to declare.

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MLL-AF4 Down-Regulates CDKN1B (P27) Independent of Cell Cycle Progression.

Blood ◽

10.1182/blood.v104.11.2563.2563 ◽

2004 ◽

Vol 104 (11) ◽

pp. 2563-2563

Author(s):

Zhenbiao Xia ◽

Relja Popovic ◽

Tara Lorenz ◽

Donna Santillan ◽

Frank Erfurth ◽

...

Keyword(s):

Cell Cycle ◽

Cell Growth ◽

Cell Line ◽

Cell Cycle Progression ◽

Target Genes ◽

Leukemia Cell ◽

Leukemia Cell Line ◽

Luciferase Reporter ◽

Cycle Progression ◽

Downstream Target

Abstract The MLL gene, involved in many chromosomal translocations associated with acute myeloid and lymphoid leukemia, has more than forty known partner genes with which it is able to form in- frame fusions. MLL fusion genes transform hematopoietic cells in vitro, and cause leukemia in mouse models. However, the mechanism is still not clear. Characterizing important downstream target genes may provide rational therapeutic strategies for the treatment of MLL-associated leukemia. We explored potential downstream target genes of the most prevalent MLL fusion protein, MLL-AF4, which is primarily associated with pro-B ALL and is involved in the majority of infant leukemia. To this end, we developed an inducible MLL-AF4 fusion cell line. Overexpression of MLL-AF4 does not lead to increased proliferation in this cell line, but rather, cell growth is slowed compared to similar cell lines inducibly expressing truncated MLL. To try to understand the reason for slower cell growth, we assayed for expression of several CDK inhibitors. We found that in the MLL-AF4 induced cell line, the amount of CDKN1B (cyclin-dependent kinase inhibitor P27) was dramatically decreased both at the RNA and protein levels, in contrast, the levels of CDKN1A (P21) and CDKN2A (P16) were unchanged. Interestingly, we did not observe an increased percentage of cells in S phase of the cell cycle. To explore whether CDKN1B might be a direct target of MLL-AF4, we employed chromatin immunoprecipitation (ChIP) assays and luciferase reporter gene assays. We observed that MLL-AF4 binds to the CDKN1B promoter in vivo and represses CDKN1B promoter activity. Further, we confirmed CDKN1B promoter binding by ChIP assays in the MLL-AF4 leukemia cell line MV4-11. Our results suggest that the CDKN1B may be a downstream target of MLL-AF4, and that MLL-AF4 inhibits CDKN1B expression independent of cell cycle progression.

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Functional Differentiation of SWI/SNF Remodelers in Transcription and Cell Cycle Control

Molecular and Cellular Biology ◽

10.1128/mcb.01257-06 ◽

2006 ◽

Vol 27 (2) ◽

pp. 651-661 ◽

Cited By ~ 91

Author(s):

Yuri M. Moshkin ◽

Lisette Mohrmann ◽

Wilfred F. J. van Ijcken ◽

C. Peter Verrijzer

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Target Genes ◽

Structural Integrity ◽

Function Analysis ◽

Cell Cycle Control ◽

Functional Differentiation ◽

Transcription Control ◽

Cycle Progression ◽

The Core

ABSTRACT Drosophila BAP and PBAP represent two evolutionarily conserved subclasses of SWI/SNF chromatin remodelers. The two complexes share the same core subunits, including the BRM ATPase, but differ in a few signature subunits: OSA defines BAP, whereas Polybromo (PB) and BAP170 specify PBAP. Here, we present a comprehensive structure-function analysis of BAP and PBAP. An RNA interference knockdown survey revealed that the core subunits BRM and MOR are critical for the structural integrity of both complexes. Whole-genome expression profiling suggested that the SWI/SNF core complex is largely dysfunctional in cells. Regulation of the majority of target genes required the signature subunit OSA, PB, or BAP170, suggesting that SWI/SNF remodelers function mostly as holoenzymes. BAP and PBAP execute similar, independent, or antagonistic functions in transcription control and appear to direct mostly distinct biological processes. BAP, but not PBAP, is required for cell cycle progression through mitosis. Because in yeast the PBAP-homologous complex, RSC, controls cell cycle progression, our finding reveals a functional switch during evolution. BAP mediates G2/M transition through direct regulation of string/cdc25. Its signature subunit, OSA, is required for directing BAP to the string/cdc25 promoter. Our results suggest that the core subunits play architectural and enzymatic roles but that the signature subunits determine most of the functional specificity of SWI/SNF holoenzymes in general gene control.

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VprBP/DCAF1 Regulates the Degradation and Nonproteolytic Activation of the Cell Cycle Transcription Factor FoxM1

Molecular and Cellular Biology ◽

10.1128/mcb.00609-16 ◽

2017 ◽

Vol 37 (13) ◽

Cited By ~ 13

Author(s):

Xianxi Wang ◽

Anthony Arceci ◽

Kelly Bird ◽

Christine A. Mills ◽

Rajarshi Choudhury ◽

...

Keyword(s):

Cell Cycle ◽

Transcription Factor ◽

Cell Cycle Progression ◽

Target Genes ◽

Chromosome Instability ◽

Vital Role ◽

Activation Mechanism ◽

Cycle Progression ◽

Protein Levels ◽

Ubiquitin System

ABSTRACT The oncogenic transcription factor FoxM1 plays a vital role in cell cycle progression, is activated in numerous human malignancies, and is linked to chromosome instability. We characterize here a cullin 4-based E3 ubiquitin ligase and its substrate receptor, VprBP/DCAF1 (CRL4VprBP), which we show regulate FoxM1 ubiquitylation and degradation. Paradoxically, we also found that the substrate receptor VprBP is a potent FoxM1 activator. VprBP depletion reduces expression of FoxM1 target genes and impairs mitotic entry, whereas ectopic VprBP expression strongly activates a FoxM1 transcriptional reporter. VprBP binding to CRL4 is reduced during mitosis, and our data suggest that VprBP activation of FoxM1 is ligase independent. This implies a nonproteolytic activation mechanism that is reminiscent of, yet distinct from, the ubiquitin-dependent transactivation of the oncoprotein Myc by other E3s. Significantly, VprBP protein levels were upregulated in high-grade serous ovarian patient tumors, where the FoxM1 signature is amplified. These data suggest that FoxM1 abundance and activity are controlled by VprBP and highlight the functional repurposing of E3 ligase substrate receptors independent of the ubiquitin system.

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