Mol. Cells 2020; 43(2): 126-138
Published online January 24, 2020
https://doi.org/10.14348/molcells.2019.0301
© The Korean Society for Molecular and Cellular Biology
Correspondence to : *Correspondence: georges.lacaud@cruk.manchester.ac.uk (GL); valerie.kouskoff@manchester.ac.uk (VK)
This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/.
The transcription factor RUNX1 first came to prominence due to its involvement in the t(8;21) translocation in acute myeloid leukemia (AML). Since this discovery, RUNX1 has been shown to play important roles not only in leukemia but also in the ontogeny of the normal hematopoietic system. Although it is currently still challenging to fully assess the different parameters regulating RUNX1 dosage, it has become clear that the dose of RUNX1 can greatly affect both leukemia and normal hematopoietic development. It is also becoming evident that varying levels of RUNX1 expression can be used as markers of tumor progression not only in the hematopoietic system, but also in non-hematopoietic cancers. Here, we provide an overview of the current knowledge of the effects of RUNX1 dosage in normal development of both hematopoietic and epithelial tissues and their associated cancers.
Keywords development, dosage, hematopoiesis, runx1, tumorigenesis
RUNX1 is the founding member of the mammalian core-binding transcription factor family which also consists of RUNX2, RUNX3 and their non-DNA binding co-factor core-binding factor beta (CBFβ) (Ito et al., 2015; Mevel et al., 2019). In humans,
Dosage reflects both the amount of protein as well as its activation status. Indeed, RUNX1 protein levels can be regulated by the rate of transcription, translation and stability. RUNX1 activity (either as activator or repressor) is also further modulated through protein conformation, intracellular localization, post-translational modifications (PTMs) and interactions with additional proteins. RUNX1 has many interacting partners and their availability depends on cell type, differentiation status and cell cycle. Describing these interactors fully lies outside the scope of this brief review and has been covered in great details in excellent recent reviews (Chuang et al., 2013; Goyama et al., 2015; Ito et al., 2015). In vertebrates, there is a high degree of homology between the different RUNX proteins both within and across species (Rennert et al., 2003). However this high degree of inter-gene similarity does not necessarily mean that mechanisms of action and regulation of RUNX1 can be extrapolated to other RUNX family members (Bruno et al., 2019). This review focuses specifically on what is known about RUNX1 in human and mouse.
Two promoters control
Finally, RUNX1 activity and stability can be modulated by various PTMs including phosphorylation, methylation, acetylation, ubiquitination, sumoylation and prolyl isomerisation (Blumenthal et al., 2017; Goyama et al., 2015; Ito et al., 2015). In Table 1, we have listed the residues in RUNX1 that have been shown to be the target of PTM and their effect on RUNX1. Few of these PTM have been extensively studied
In mammalian embryogenesis, the hematopoietic system is established via several consecutive waves of blood cell generation (Dzierzak and Bigas, 2018). In mice, the first wave generates primitive erythrocytes at embryonic day 7.25 (E7.25). It is followed by the emergence of erythroid myeloid progenitors at E8.25, and lymphoid myeloid progenitors at E9.5. The final wave of hematopoiesis at E10.5 takes place in the aorta-gonad-mesonephros (AGM) region of the embryo proper and generates the first hematopoietic stem cells (HSCs). The HSCs then migrate to the fetal liver (E12.5) where they multiply and mature before colonizing the bone marrow (E16.5). Except for the first wave, RUNX1 is absolutely required for blood cell formation (Chen et al., 2009; Lancrin et al., 2009; North et al., 1999; Okuda et al., 1996; Wang et al., 1996a; Yokomizo et al., 2008). At all sites of
Detailed studies using reporter mice and mouse embryonic stem cell lines (mESCs) demonstrated that the P2 promoter (
In human, the picture is less clear. Early publications indicate that during human ESCs (hESCs) differentiation the expression of
Modulation of gene dosage has been extensively used to assess the effect of RUNX1 dosage changes in ontogeny. Although total
Taken together, the current data indicate that the initial establishment of the hematopoietic system relies on a low dose of RUNX1 and that careful modulation of this low dose controls the dynamic and progression of blood formation (Fig. 1C).
Considering its importance in the ontogeny of the hematopoietic system, it is not surprising that
In terms of dosage, high levels of
In AMLs, increased
The role of RUNX1 dosage during the development and homeostasis of epithelial tissues remains less documented than in the hematopoietic setting. However, increasing evidence suggests a role for RUNX1 in various non-hematopoietic tissues of epithelial origin (reviewed in Mevel et al., 2019). Indeed, high throughput next-generation sequencing has revealed relatively high frequencies of genomic alterations of
Hormone-related cancers constitute some of the most common cancers in women and men, and
In contrast to its putative tumor suppressive functions, RUNX1 is also believed to be associated with oncogenic roles. Indeed, higher
Beyond breast cancer, overexpression of
Although less substantial than in female-related cancers, there is accumulating evidence for a potential role of RUNX1 in prostate cancer. Single-nucleotide polymorphisms within the
In keeping with its role in hematopoiesis,
RUNX1 has also been linked with tumors of the gastrointestinal tract, where it was found to be frequently downregulated (Miyagawa et al., 2006; Sakakura et al., 2005). In conditional mouse models,
It is now well established that RUNX1 dosage is important during normal development and homeostasis of hematopoietic tissues, and there is a growing body of evidence indicating that it is important in epithelial tissues as well. These studies highlight the multifaceted characteristics of RUNX1, in particular in non-hematopoietic tissues, where it was not originally thought to be involved. Alterations of RUNX1 dosage in these tissues were initially revealed by large scale genomic studies and these results are reinforced by growing experimental evidence implicating RUNX1 in crucial hallmarks of cancer progression such as cell proliferation, EMT or DNA repair (Tay et al., 2018). It has now become clear that RUNX1 can act both as an oncogenic or a tumor-suppressive factor (Blyth et al., 2005; Ito et al., 2015; Neil et al., 2017). Intriguingly, the implication of RUNX1 in both female and male related cancers has revealed a close relationship with ER and AR, which warrants further investigations. While the functional evidence between RUNX1 dosage and cancer development is often still lacking and requires further work, it has become evident that varying levels of RUNX1 expression can be used as markers of tumor progression in specific clinical cohorts (Fig. 2C).
Finally, although systems modifying RUNX1 dosage via (conditional) knock-out alleles as well as controlled transcriptional regulation provide valuable information on how RUNX1 dosage can affect normal physiology and cancer, detailed stage and cell type-specific information on physiological RUNX1 dosage levels would drive our understanding even further. In this context, it should be emphasized that when evaluating RUNX1 dosage, both the amount of protein as well as its activation status should be taken into consideration. Currently, it is still very challenging to fully assess the different parameters regulating RUNX1 dosages. However, the continuous improvement of single-cell technologies might soon allow us to interrogate, at a single-cell level, the quantity and ratios of RUNX1 isoforms, as well as their PTMs. Such data would provide valuable insights on RUNX1 dosage at the single cell level and would allow us to better investigate their functions.
The authors have no potential conflicts of interest to disclose.
Post translational modifications of RUNX1
Post translational modification | Effect | Modifier | Target domain | Target residues (Runx1b) |
---|---|---|---|---|
Serine/threonine phosphorylation (1) | Increased transactivation, decreased stability | ERK | Predominatly C-term transactivaton domain | S249, S266, S276, S435, T273 |
Serine/threonine phosphorylation (1) | Increased transactivation, decreased stability | Hip2k | Predominatly C-term transactivaton domain | S249, S276, T273 |
Serine/threonine phosphorylation (1, 2) | Increased transactivation, decreased stability | CDK | Predominatly C-term transactivaton domain | S21, S249, S266, S276, S397, T273 |
Tyrosine phosphorylation (3) | Increased transactivation, increased stability, reduced HDAC interaction, increased DNA binding | Src kinase | Predominatly C-term inhibitory domain | Y260, Y375, Y378, Y379, Y386 |
Methylation (4) | Reduced SIN3a interaction, increased transactivation activity | PRMT1 | C-term inhibitory domain | R2016 and R210 |
Methylation (5) | Reduced transactivation via increased co-repressor DPF2 binding | PRMT4 | C-term transactivation domain | R223 |
Acetylation (6) | Reduced DNA binding, reduced transactivation | p300/CBP | N-terminus | K24, K43 |
Ubiquitination (7) | Increased degradation | STUB1 E3 ubiquitin ligase | Predominantly runt domain | K24, K43, K83, 90, 125, 144, 167, 182, 188 (potential targets) |
SUMOylation (8) | Unknown (reduced transactivation shown for RUNX3) | PIAS1 | Runt domain | K144 |
Prolyl isomerization (9) | Increased acetylation, stability and transactivation activity | PIN1 | Not defined | Not defined |
Currently described post translational modifications of RUNX1 and their effect on RUNX1. All amino acid residues are numbered based on RUNX1b. The number between brackets (#) refers to the following citations: 1, (Aikawa et al., 2006; Biggs et al., 2006; Imai et al., 2004; Tanaka et al., 1996; Wee et al., 2008; Zhang et al., 2004); 2, (Guo and Friedman, 2011); 3, (Huang et al., 2012; Leong et al., 2016); 4, (Zhao et al., 2008); 5, (Vu et al., 2013); 6, (Yamaguchi et al., 2004); 7, (Shang et al., 2009; Yonezawa et al., 2017); 8, (Kim et al., 2014); 9, (Islam et al., 2014).
Mol. Cells 2020; 43(2): 126-138
Published online February 29, 2020 https://doi.org/10.14348/molcells.2019.0301
Copyright © The Korean Society for Molecular and Cellular Biology.
Michael Lie-a-ling1,6 , Renaud Mevel1,6
, Rahima Patel1
, Karen Blyth2,3
, Esther Baena4
, Valerie Kouskoff5,*
, and Georges Lacaud1,*
1Cancer Research UK Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Macclesfield, SK10 4TG, UK, 2Cancer Research UK Beatson Institute, Glasgow, G61 1BD, UK, 3Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK, 4Cancer Research UK Prostate Oncobiology Group, Cancer Research UK Manchester Institute, The University of Manchester, Macclesfield, SK10 4TG, UK, 5Division of Developmental Biology & Medicine, The University of Manchester, Manchester, M13 9PT, UK, 6These authors contributed equally to this work.
Correspondence to:*Correspondence: georges.lacaud@cruk.manchester.ac.uk (GL); valerie.kouskoff@manchester.ac.uk (VK)
This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/.
The transcription factor RUNX1 first came to prominence due to its involvement in the t(8;21) translocation in acute myeloid leukemia (AML). Since this discovery, RUNX1 has been shown to play important roles not only in leukemia but also in the ontogeny of the normal hematopoietic system. Although it is currently still challenging to fully assess the different parameters regulating RUNX1 dosage, it has become clear that the dose of RUNX1 can greatly affect both leukemia and normal hematopoietic development. It is also becoming evident that varying levels of RUNX1 expression can be used as markers of tumor progression not only in the hematopoietic system, but also in non-hematopoietic cancers. Here, we provide an overview of the current knowledge of the effects of RUNX1 dosage in normal development of both hematopoietic and epithelial tissues and their associated cancers.
Keywords: development, dosage, hematopoiesis, runx1, tumorigenesis
RUNX1 is the founding member of the mammalian core-binding transcription factor family which also consists of RUNX2, RUNX3 and their non-DNA binding co-factor core-binding factor beta (CBFβ) (Ito et al., 2015; Mevel et al., 2019). In humans,
Dosage reflects both the amount of protein as well as its activation status. Indeed, RUNX1 protein levels can be regulated by the rate of transcription, translation and stability. RUNX1 activity (either as activator or repressor) is also further modulated through protein conformation, intracellular localization, post-translational modifications (PTMs) and interactions with additional proteins. RUNX1 has many interacting partners and their availability depends on cell type, differentiation status and cell cycle. Describing these interactors fully lies outside the scope of this brief review and has been covered in great details in excellent recent reviews (Chuang et al., 2013; Goyama et al., 2015; Ito et al., 2015). In vertebrates, there is a high degree of homology between the different RUNX proteins both within and across species (Rennert et al., 2003). However this high degree of inter-gene similarity does not necessarily mean that mechanisms of action and regulation of RUNX1 can be extrapolated to other RUNX family members (Bruno et al., 2019). This review focuses specifically on what is known about RUNX1 in human and mouse.
Two promoters control
Finally, RUNX1 activity and stability can be modulated by various PTMs including phosphorylation, methylation, acetylation, ubiquitination, sumoylation and prolyl isomerisation (Blumenthal et al., 2017; Goyama et al., 2015; Ito et al., 2015). In Table 1, we have listed the residues in RUNX1 that have been shown to be the target of PTM and their effect on RUNX1. Few of these PTM have been extensively studied
In mammalian embryogenesis, the hematopoietic system is established via several consecutive waves of blood cell generation (Dzierzak and Bigas, 2018). In mice, the first wave generates primitive erythrocytes at embryonic day 7.25 (E7.25). It is followed by the emergence of erythroid myeloid progenitors at E8.25, and lymphoid myeloid progenitors at E9.5. The final wave of hematopoiesis at E10.5 takes place in the aorta-gonad-mesonephros (AGM) region of the embryo proper and generates the first hematopoietic stem cells (HSCs). The HSCs then migrate to the fetal liver (E12.5) where they multiply and mature before colonizing the bone marrow (E16.5). Except for the first wave, RUNX1 is absolutely required for blood cell formation (Chen et al., 2009; Lancrin et al., 2009; North et al., 1999; Okuda et al., 1996; Wang et al., 1996a; Yokomizo et al., 2008). At all sites of
Detailed studies using reporter mice and mouse embryonic stem cell lines (mESCs) demonstrated that the P2 promoter (
In human, the picture is less clear. Early publications indicate that during human ESCs (hESCs) differentiation the expression of
Modulation of gene dosage has been extensively used to assess the effect of RUNX1 dosage changes in ontogeny. Although total
Taken together, the current data indicate that the initial establishment of the hematopoietic system relies on a low dose of RUNX1 and that careful modulation of this low dose controls the dynamic and progression of blood formation (Fig. 1C).
Considering its importance in the ontogeny of the hematopoietic system, it is not surprising that
In terms of dosage, high levels of
In AMLs, increased
The role of RUNX1 dosage during the development and homeostasis of epithelial tissues remains less documented than in the hematopoietic setting. However, increasing evidence suggests a role for RUNX1 in various non-hematopoietic tissues of epithelial origin (reviewed in Mevel et al., 2019). Indeed, high throughput next-generation sequencing has revealed relatively high frequencies of genomic alterations of
Hormone-related cancers constitute some of the most common cancers in women and men, and
In contrast to its putative tumor suppressive functions, RUNX1 is also believed to be associated with oncogenic roles. Indeed, higher
Beyond breast cancer, overexpression of
Although less substantial than in female-related cancers, there is accumulating evidence for a potential role of RUNX1 in prostate cancer. Single-nucleotide polymorphisms within the
In keeping with its role in hematopoiesis,
RUNX1 has also been linked with tumors of the gastrointestinal tract, where it was found to be frequently downregulated (Miyagawa et al., 2006; Sakakura et al., 2005). In conditional mouse models,
It is now well established that RUNX1 dosage is important during normal development and homeostasis of hematopoietic tissues, and there is a growing body of evidence indicating that it is important in epithelial tissues as well. These studies highlight the multifaceted characteristics of RUNX1, in particular in non-hematopoietic tissues, where it was not originally thought to be involved. Alterations of RUNX1 dosage in these tissues were initially revealed by large scale genomic studies and these results are reinforced by growing experimental evidence implicating RUNX1 in crucial hallmarks of cancer progression such as cell proliferation, EMT or DNA repair (Tay et al., 2018). It has now become clear that RUNX1 can act both as an oncogenic or a tumor-suppressive factor (Blyth et al., 2005; Ito et al., 2015; Neil et al., 2017). Intriguingly, the implication of RUNX1 in both female and male related cancers has revealed a close relationship with ER and AR, which warrants further investigations. While the functional evidence between RUNX1 dosage and cancer development is often still lacking and requires further work, it has become evident that varying levels of RUNX1 expression can be used as markers of tumor progression in specific clinical cohorts (Fig. 2C).
Finally, although systems modifying RUNX1 dosage via (conditional) knock-out alleles as well as controlled transcriptional regulation provide valuable information on how RUNX1 dosage can affect normal physiology and cancer, detailed stage and cell type-specific information on physiological RUNX1 dosage levels would drive our understanding even further. In this context, it should be emphasized that when evaluating RUNX1 dosage, both the amount of protein as well as its activation status should be taken into consideration. Currently, it is still very challenging to fully assess the different parameters regulating RUNX1 dosages. However, the continuous improvement of single-cell technologies might soon allow us to interrogate, at a single-cell level, the quantity and ratios of RUNX1 isoforms, as well as their PTMs. Such data would provide valuable insights on RUNX1 dosage at the single cell level and would allow us to better investigate their functions.
The authors have no potential conflicts of interest to disclose.
Post translational modifications of RUNX1
Post translational modification | Effect | Modifier | Target domain | Target residues (Runx1b) |
---|---|---|---|---|
Serine/threonine phosphorylation (1) | Increased transactivation, decreased stability | ERK | Predominatly C-term transactivaton domain | S249, S266, S276, S435, T273 |
Serine/threonine phosphorylation (1) | Increased transactivation, decreased stability | Hip2k | Predominatly C-term transactivaton domain | S249, S276, T273 |
Serine/threonine phosphorylation (1, 2) | Increased transactivation, decreased stability | CDK | Predominatly C-term transactivaton domain | S21, S249, S266, S276, S397, T273 |
Tyrosine phosphorylation (3) | Increased transactivation, increased stability, reduced HDAC interaction, increased DNA binding | Src kinase | Predominatly C-term inhibitory domain | Y260, Y375, Y378, Y379, Y386 |
Methylation (4) | Reduced SIN3a interaction, increased transactivation activity | PRMT1 | C-term inhibitory domain | R2016 and R210 |
Methylation (5) | Reduced transactivation via increased co-repressor DPF2 binding | PRMT4 | C-term transactivation domain | R223 |
Acetylation (6) | Reduced DNA binding, reduced transactivation | p300/CBP | N-terminus | K24, K43 |
Ubiquitination (7) | Increased degradation | STUB1 E3 ubiquitin ligase | Predominantly runt domain | K24, K43, K83, 90, 125, 144, 167, 182, 188 (potential targets) |
SUMOylation (8) | Unknown (reduced transactivation shown for RUNX3) | PIAS1 | Runt domain | K144 |
Prolyl isomerization (9) | Increased acetylation, stability and transactivation activity | PIN1 | Not defined | Not defined |
Currently described post translational modifications of RUNX1 and their effect on RUNX1. All amino acid residues are numbered based on RUNX1b. The number between brackets (#) refers to the following citations: 1, (Aikawa et al., 2006; Biggs et al., 2006; Imai et al., 2004; Tanaka et al., 1996; Wee et al., 2008; Zhang et al., 2004); 2, (Guo and Friedman, 2011); 3, (Huang et al., 2012; Leong et al., 2016); 4, (Zhao et al., 2008); 5, (Vu et al., 2013); 6, (Yamaguchi et al., 2004); 7, (Shang et al., 2009; Yonezawa et al., 2017); 8, (Kim et al., 2014); 9, (Islam et al., 2014).
. Post translational modifications of RUNX1.
Post translational modification | Effect | Modifier | Target domain | Target residues (Runx1b) |
---|---|---|---|---|
Serine/threonine phosphorylation (1) | Increased transactivation, decreased stability | ERK | Predominatly C-term transactivaton domain | S249, S266, S276, S435, T273 |
Serine/threonine phosphorylation (1) | Increased transactivation, decreased stability | Hip2k | Predominatly C-term transactivaton domain | S249, S276, T273 |
Serine/threonine phosphorylation (1, 2) | Increased transactivation, decreased stability | CDK | Predominatly C-term transactivaton domain | S21, S249, S266, S276, S397, T273 |
Tyrosine phosphorylation (3) | Increased transactivation, increased stability, reduced HDAC interaction, increased DNA binding | Src kinase | Predominatly C-term inhibitory domain | Y260, Y375, Y378, Y379, Y386 |
Methylation (4) | Reduced SIN3a interaction, increased transactivation activity | PRMT1 | C-term inhibitory domain | R2016 and R210 |
Methylation (5) | Reduced transactivation via increased co-repressor DPF2 binding | PRMT4 | C-term transactivation domain | R223 |
Acetylation (6) | Reduced DNA binding, reduced transactivation | p300/CBP | N-terminus | K24, K43 |
Ubiquitination (7) | Increased degradation | STUB1 E3 ubiquitin ligase | Predominantly runt domain | K24, K43, K83, 90, 125, 144, 167, 182, 188 (potential targets) |
SUMOylation (8) | Unknown (reduced transactivation shown for RUNX3) | PIAS1 | Runt domain | K144 |
Prolyl isomerization (9) | Increased acetylation, stability and transactivation activity | PIN1 | Not defined | Not defined |
Currently described post translational modifications of RUNX1 and their effect on RUNX1. All amino acid residues are numbered based on RUNX1b. The number between brackets (#) refers to the following citations: 1, (Aikawa et al., 2006; Biggs et al., 2006; Imai et al., 2004; Tanaka et al., 1996; Wee et al., 2008; Zhang et al., 2004); 2, (Guo and Friedman, 2011); 3, (Huang et al., 2012; Leong et al., 2016); 4, (Zhao et al., 2008); 5, (Vu et al., 2013); 6, (Yamaguchi et al., 2004); 7, (Shang et al., 2009; Yonezawa et al., 2017); 8, (Kim et al., 2014); 9, (Islam et al., 2014)..
Boyoon Choi, Hyeyoung Kim, Jungim Jang, Sihyeon Park, and Hosung Jung
Mol. Cells 2022; 45(11): 846-854 https://doi.org/10.14348/molcells.2022.0081An Song, Yi Wang, Feng Jiang, Enshi Yan, Junbo Zhou, Jinhai Ye, Hongchuang Zhang, Xu Ding, Gang Li, Yunong Wu, Yang Zheng, and Xiaomeng Song
Mol. Cells 2021; 44(7): 468-480 https://doi.org/10.14348/molcells.2021.2229Yeon Duk Woo, Dongjin Jeong, and Doo Hyun Chung
Mol. Cells 2021; 44(5): 292-300 https://doi.org/10.14348/molcells.2021.0058