Involvement of ERK1/2, p38 MAPK, and PI3K/Akt signaling pathways in the regulation of cell cycle progression by PTHrP in colon adenocarcinoma cells

2014 ◽  
Vol 92 (4) ◽  
pp. 305-315 ◽  
Author(s):  
Natalia Calvo ◽  
María Julia Martín ◽  
Ana Russo de Boland ◽  
Claudia Gentili

Parathyroid hormone-related peptide (PTHrP) is distributed in most fetal and adult tissues, and its expression correlates with the severity of colon carcinoma. Recently we obtained evidence that in Caco-2 cells, a cell line from human colorectal adenocarcinoma, exogenous PTHrP increases the number of live cells, via ERK1/2, p38 MAPK, and PI3-kinase and induces the expression of cyclin D1, a cell cycle regulatory protein. In this study, we further investigated the role of PTHrP in the regulation of the cell cycle progression in these intestinal cells. Flow cytometry analysis revealed that PTHrP treatment diminishes the number of cells in the G0/G1 phase and increases the number in both S and G2/M phases. The hormone increases the expression of CDK6 and diminishes the amount of negative cell cycle regulators p27Kip1, p15INK4B, and p53. However, PTHrP does not modify the expression of cyclin D3, CDK4, and p16INK4A. In addition, inhibitors of ERK1/2 (PD98059), p38 MAPK (SB203580), and PI3Kinase (LY294002) reversed PTHrP response in Caco-2 cells. Taken together, our results suggest that PTHrP positively modulates cell cycle progression and changes the expression of proteins involved in cell cycle regulation via ERK1/2, p38 MAPK, and PI3K signaling pathways in Caco-2 cells.

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3380-3380
Author(s):  
Vishal A Salunkhe ◽  
Iain Macaulay ◽  
Sylvia Nuernberg ◽  
Cathal McCarthy ◽  
Willem Hendrik Ouwehand ◽  
...  

Abstract Abstract 3380 Haematopoiesis is highly coordinated process of fate determination at branch points that is regulated by transcription factors and their cofactors. Our comprehensive catalogue of transcripts in the eight main mature blood cell elements, including erythroblasts and megakaryocytes (MKs) showed that the transcription factor MEIS1 is uniquely transcribed in MKs and the CD34+ haematopoietic stem cell. Gene silencing studies in mice and zebrafish has shown a pivotal role for MEIS1 in haematopoiesis, megakaryopoiesis and vasculogenesis, although its precise hierarchical position and function remain unknown. To gain further insight in the role of MEIS1 in megakaryopoiesis, we used a proteomics approach to search for its nuclear interaction partners. Co-immunoprecipitation was used to isolate MEIS1 interacting proteins from the nuclear fraction of the MK cell line, CHRF 288–11 and resulting eluates were subjected to proteomics analysis using one-dimensional electrophoresis and liquid chromatography (LC) coupled to tandem mass spectrometry (MS) or GeLC-MS/MS. In total 70 proteins were identified to co-immunoprecipitate with MEIS1 from 3 replicate MS analyses. These included the previously validated MEIS1 interactors PBX1 and HOXB9, as well as numerous novel interactors such as ARID3B and DHX9. Network analysis of our MEIS1 interactome dataset revealed a strong association with cell cycle regulation. In fact, we had identified a myriad of cell cycle regulators including CDK1, CDK2, CDK9, CUL3, PCNA, CDC5L, ARID3B and MDC1. These interactions are consistent with recent microarray studies in promyelocytic leukemic cell lines that link MEIS1 with cell cycle entry and its regulation of genes such as CDK2, CDK6, CDKN3, CDC7 and Cyclin D3 among others. To confirm the novel interaction of MK MEIS1 with cell cycle regulators we performed reverse immuno-precipitation/immunoblot analysis in CHRF cells and purified MEIS1 containing multiprotein complexes from L8057 murine megakaryoblastic cells. Using a cell cycle specific PCR array, we demonstrate that MEIS1 overexpression in L8057 cells regulates numerous cell cycle regulatory genes. Preliminary analysis using flow cytometry demonstrated that MEIS1 overexpression resulted in an altered cell cycle progression. Furthermore, genome wide ChIP-Seq analysis in CHRF cells for MEIS1 revealed binding sites in Cyclin D3 and CDK6, two known key regulators of the cell cycle and megakaryopoiesis. Taken together this study provides evidence linking MEIS1 to the cell cycle control of MKs and will help elucidate the role of MEIS1 in cell cycle progression, megakaryopoiesis and associated disorders. Disclosures: No relevant conflicts of interest to declare.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Wei Liu ◽  
Hongmiao Ren ◽  
Jihao Ren ◽  
Tuanfang Yin ◽  
Bing Hu ◽  
...  

Cholesteatoma is a benign keratinizing and hyper proliferative squamous epithelial lesion of the temporal bone. Epidermal growth factor (EGF) is one of the most important cytokines which has been shown to play a critical role in cholesteatoma. In this investigation, we studied the effects of EGF on the proliferation of keratinocytes and EGF-mediated signaling pathways underlying the pathogenesis of cholesteatoma. We examined the expressions of phosphorylated EGF receptor (p-EGFR), phosphorylated Akt (p-Akt), cyclinD1, and proliferating cell nuclear antigen (PCNA) in 40 cholesteatoma samples and 20 samples of normal external auditory canal (EAC) epithelium by immunohistochemical method. Furthermore,in vitrostudies were performed to investigate EGF-induced downstream signaling pathways in primary external auditory canal keratinocytes (EACKs). The expressions of p-EGFR, p-Akt, cyclinD1, and PCNA in cholesteatoma epithelium were significantly increased when compared with those of control subjects. We also demonstrated that EGF led to the activation of the EGFR/PI3K/Akt/cyclinD1 signaling pathway, which played a critical role in EGF-induced cell proliferation and cell cycle progression of EACKs. Both EGFR inhibitor AG1478 and PI3K inhibitor wortmannin inhibited the EGF-induced EGFR/PI3K/Akt/cyclinD1 signaling pathway concomitantly with inhibition of cell proliferation and cell cycle progression of EACKs. Taken together, our data suggest that the EGFR/PI3K/Akt/cyclinD1 signaling pathway is active in cholesteatoma and may play a crucial role in cholesteatoma epithelial hyper-proliferation. This study will facilitate the development of potential therapeutic targets for intratympanic drug therapy for cholesteatoma.


2007 ◽  
Vol 4 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Masaki Kawamura ◽  
Hirotake Kasai

We examined the effects of hemicellulase-treatedAgaricus blazei(AB fraction H, ABH) on growth of several tumor cell lines. ABH inhibited the proliferation of some cell lines without cytotoxic effects. It markedly prolonged the S phase of the cell cycle. ABH also induced mitochondria-mediated apoptosis in different cell lines. However, it had no impact on the growth of other cell lines. ABH induced strong activation of p38 mitogen-activated protein kinase (MAPK) in the cells in which it evoked apoptosis. On the other hand, ABH showed only a weak p38 activation effect in those cell lines in which it delayed cell cycle progression with little induction of apoptosis. However, p38 MAPK-specific inhibitor inhibited both ABH-induced effects, and ABH also caused apoptosis in the latter cells under conditions of high p38 MAPK activity induced by combined treatment with TNF-α. These results indicate that the responsiveness of p38 MAPK to ABH, which differs between cell lines, determines subsequent cellular responses on cell growth.


2017 ◽  
Author(s):  
Shixuan Liu ◽  
Miriam B. Ginzberg ◽  
Nish Patel ◽  
Marc Hild ◽  
Bosco Leung ◽  
...  

AbstractAnimal cells within a tissue typically display a striking regularity in their size. To date, the molecular mechanisms that control this uniformity are still unknown. We have previously shown that size uniformity in animal cells is promoted, in part, by size-dependent regulation of G1 length. To identify the molecular mechanisms underlying this process, we performed a large-scale small molecule screen and found that the p38 MAPK pathway is involved in coordinating cell size and cell cycle progression. Small cells display higher p38 activity and spend more time in G1 than larger cells. Inhibition of p38 MAPK leads to loss of the compensatory G1 length extension in small cells, resulting in faster proliferation, smaller cell size and increased size heterogeneity. We propose a model wherein the p38 pathway responds to changes in cell size and regulates G1 exit accordingly, to increase cell size uniformity.One-sentence summaryThe p38 MAP kinase pathway coordinates cell growth and cell cycle progression by lengthening G1 in small cells, allowing them more time to grow before their next division.


Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3327
Author(s):  
Zhixiang Wang

The cell cycle is the series of events that take place in a cell, which drives it to divide and produce two new daughter cells. The typical cell cycle in eukaryotes is composed of the following phases: G1, S, G2, and M phase. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that control the activity of various Cdk–cyclin complexes. While the mechanism underlying the role of growth factor signaling in G1 phase of cell cycle progression has been largely revealed due to early extensive research, little is known regarding the function and mechanism of growth factor signaling in regulating other phases of the cell cycle, including S, G2, and M phase. In this review, we briefly discuss the process of cell cycle progression through various phases, and we focus on the role of signaling pathways activated by growth factors and their receptor (mostly receptor tyrosine kinases) in regulating cell cycle progression through various phases.


Sign in / Sign up

Export Citation Format

Share Document