Inhibitor of differentiation 4 drives brain tumor-initiating cell genesis through cyclin E and notch signaling

Abstract

Cellular origins and genetic factors governing the genesis and maintenance of glioblastomas (GBM) are not well understood. Here, we report a pathogenetic role of the developmental regulator Id4 (inhibitor of differentiation 4) in GBM. In primary murine Ink4a/Arf −/− astrocytes, and human glioma cells, we provide evidence that enforced Id4 can drive malignant transformation by stimulating increased cyclin E to produce a hyperproliferative profile and by increased Jagged1 expression with Notch1 activation to drive astrocytes into a neural stem-like cell state. Thus, Id4 plays an integral role in the transformation of astrocytes via its combined actions on two-key cell cycle and differentiation regulatory molecules.Supplemental material is available at http://www.genesdev.org. The self-renewal, differentiative, and proliferative states of tissue stem and progenitor cells are maintained by a variety of well-defined cell fate determinant factors (Keller 2005). Disregulation of such key developmental regulators and acquisition and maintenance of an immature differentiation phenotype are common themes across a broad spectrum of cancer types, including primary brain cancers (Garraway and Sellers 2006). Indeed, a growing body of evidence supports the view that developmental regulators play direct roles in driving aspiring cancer cells toward a malignant phenotype, one that is endowed with stem-like cell properties including robust renewal potential (Beachy et al. 2004). This cellular phenotype, embodied in the cancer stem cell paradigm (Pardal et al. 2003), has been well documented in the highly malignant brain cancer, primary glioblastoma multiforme (GBM) (Galli et al. 2004;Singh et al. 2004). The cellular origins and specific genetic elements involved in the genesis and maintenance of these so-called brain cancer stem cells (BCSCs) remain areas of intensive investigation. Results and Discussion Id4 is overexpressed human GBM, and can drive transformation of murine Ink4a/Arf −/− astrocytesGiven the biological significance of stem cell fate determinants in the regulation of normal self-renewal and differentiation, we hypothesized that the genetic or epigenetic alterations in classical cell fate determinants might cooperate with prototypical oncogenes and tumor suppressor genes to both effect malignant transformation and endow stem cell-like renewal activity in these tumors (Leung et al. 2004;Ligon et al. 2007). We were particularly focused on the expression and functional activity of inhibitor of differentiation 4 (Id4) in GBM given its prominent role in governing neural stem cell (NSC) fate decisions (Yun et al. 2004). Id4 mRNA levels were found to be increased in nine of 15 GBM samples as compared with human normal brain tissue (Supplemental Fig. S1A) and abundant Id4 mRNA and protein levels were detected in five of seven human glioma cell lines (A172, LN229, LN18, U87MG, and T98G) and an immortalized human NSC line (HB1.F3) (Cho et al. 2002), but not in the normal human astrocytes (NHA) (Supplemental Fig. S1B). Tumor ...

Inhibitor of DNA binding-4 promotes angiogenesis and growth of glioblastoma multiforme by elevating matrix GLA levels

“…Expanding on past work (AndresBarquin et al, 1997; Vandeputte et al, 2002;Jeon et al, 2008), we found ID4 elevated in glioblastoma multiforme (GBM), a highly aggressive and well-vascularized brain tumor that is refractory to existing therapies (Kleihues and Cavenee, 1997). The difficulties in treating this tumor led us to investigate the potential function of ID4 in the pathogenesis of glioblastoma.…”

“…ID family members including ID1, ID2, and ID3 have identified functions in tumor progression, including angiogenesis, invasion, and metastasis (Lyden et al, 1999;Benezra, 2001;Benezra et al, 2001;Folkman, 2002;Ruzinova and Benezra, 2003;, and in other circumstances ID1 and ID2 may function as tumor suppressors in rodents (Itahana et al, 2003;Sikder et al, 2003;Russell et al, 2004). The function of ID4 in tumorigenesis is similarly complex (Beger et al, 2001;Bellido et al, 2003;Chan et al, 2003;Shan et al, 2003;Umetani et al, 2004Umetani et al, , 2005 Jeon et al, 2008). ID4 seems to function as a tumor suppressor in a variety of cancers (Chan et al, 2003;Umetani et al, 2004Umetani et al, , 2005Yu et al, 2005) and is downregulated by promoter hypermethylation in several tumor types (Chan et al, 2003;Umetani et al, 2004Umetani et al, , 2005Yu et al, 2005).…”

“…ID4 seems to function as a tumor suppressor in a variety of cancers (Chan et al, 2003;Umetani et al, 2004Umetani et al, , 2005Yu et al, 2005) and is downregulated by promoter hypermethylation in several tumor types (Chan et al, 2003;Umetani et al, 2004Umetani et al, , 2005Yu et al, 2005). In sharp contrast, however, ID4 promotes some aspects of tumorigenesis in B-cell lineage ALL, glioblastoma, and sporadic breast and ovarian cancers (Beger et al, 2001;Bellido et al, 2003;Jeon et al, 2008), and its expression is heightened in bladder cancer because of gene amplification .…”

“…Typically, they are highly expressed during embryogenesis and at lower levels in mature tissues with the exception of some stem cells (Yun et al, 2004) and many cancers, including brain tumors (AndresBarquin et al, 1997;Vandeputte et al, 2002;Jeon et al, 2008). Expression of ID family members has been associated with features of malignancies (Ruzinova and Benezra, 2003), including cellular transformation, immortalization, enhanced proliferation, migration, invasion, metastasis, angiogenesis, and maintenance of tumor-initiating cells (Jeon et al, 2008).…”

The brain tumor microenvironment

“…Notch signaling is a critical developmental pathway that controls neural stem cell fate and suppresses radial glia differentiation (Ehebauer et al, 2006). The notch signaling pathway is constitutively active in many high-grade gliomas and has been associated with progression of gliomas (Hulleman et al, 2009;Jeon et al, 2008;Shih and Holland, 2006;Zhang et al, 2008). Notch signaling from endothelial cells to hematopoetic stem cells (HSC) via expression of Notch ligands has been shown to drive the self-renewal characteristics and in vivo repopulation of long-term HSCs that lie adjacent to the vasculature (Butler et al, 2010).…”