The new tumor-suppressor gene inhibitor of growth family member 4 (ING4) regulates the production of proangiogenic molecules by myeloma cells and suppresses hypoxia-inducible factor-1 α (HIF-1α) activity: involvement in myeloma-induced angiogenesis

Abstract

IntroductionAngiogenesis has a critical role in the pathophysiology and progression of multiple myeloma (MM) supporting the growth and survival of MM cells. [1][2][3][4][5] The angiogenic process in MM is sustained mainly by the overexpression of proangiogenic factors directly by MM cells including VEGF, 6 angiopoietin-1 (ANG-1), 7 osteopontin (OPN), . 9 Nevertheless, the molecular mechanisms underlying the regulation of angiogenesis in MM have not been completely elucidated.The new candidate tumor-suppressor gene inhibitor of growth family member 4 (ING4) has been recently implicated in solid tumors as a repressor of tumor growth and angiogenesis through the association with NF-B. ING4 is a nuclear factor expressed in all normal tissues and markedly reduced in glioblastoma cells and head and neck squamous cell carcinoma, with levels inversely correlated with tumor grade. 10,11 Inhibition of ING4 expression strongly promotes the growth of glioma cells in vivo, whereas its overexpression leads to growth inhibition through ING4's capability to interact with p65 subunit of NF-B. 10 Interestingly, it has been also shown that tumors lacking ING4 showed increased vascularization compared with ING4-expressing tumors. 12 Moreover ING4 down-regulated the angiogenic-related molecules including IL-8 and the hypoxia inducible factor-1␣ (HIF-1 ␣) activity in hypoxic condition through the involvement of HIF prolyl hydroxylase 2 (HPH-2) 10,13 In turn, the role of hypoxia has been recently highlighted in the promotion of angiogenesis. 14 The expression of ING4 by MM cells, as well as its potential role in MM-induced angiogenesis, has never been investigated. In this study, we evaluated the expression of ING4 in malignant MM cells and the potential relationship between ING4 and the production of proangiogenic molecules by MM cells in normoxic and hypoxic conditions, as well as its relationship with the "in vitro and in vivo" angiogenesis. Submitted February 15, 2007; accepted September 4, 2007. Prepublished online as Blood First Edition paper, September 11, 2007; DOI 10.1182 DOI 10. /blood-2007 The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked ''advertisement'' in accordance with 18 USC section 1734. For personal use only. on August 29, 2018. by guest www.bloodjournal.org From Patients, materials, and methods Cells and cell culture conditionsCell lines. Human myeloma cell lines (HMCLs) XG-6, XG-1, and JJN3 were obtained from Dr Bataille (Nantes, France). U266 was obtained from the American Type Culture Collection (Rockville, MD). OPM2 and RPMI-8226 were purchased from DSM (Braunschweig, Germany). ARP-1 and H929 were generously received from Dr Shaughnessy's laboratory (Little Rock, AR).Cell cultures. HMCLs were incubated in RPMI medium at 10% FCS (Invitrogen Life Technologies, Milan, Italy) and maintained with or without IL-6 (3 ng/mL; Endogen Woburn, MA). In a series of experiments, HMCLs were incubated with the HPH-2 in...

Hypoxia-inducible factor (HIF)-1α suppression in myeloma cells blocks tumoral growth in vivo inhibiting angiogenesis and bone destruction

“…The capacity of HIF-1a to regulate VEGFA and IL8 gene expression by MM cells confirmed our previous data, 27,39 and supports HIF-1a as a key regulator of angiogenesis also in MM cells because VEGF 9,10 and at least in part of IL-8 39,40 are well-known factors involved in MM-induced angiogenesis. CCL2 and MMP9 could be also involved in the pro-angiogenic role of HIF-1a, because both cytokines are produced by MM cells and contribute to angiogenesis and BM spreading.…”

Angiogenesis and Multiple Myeloma

“…Moreover, ING4 down-regulated angiogenesis related molecules including IL-8 and HIF-1α [117,119]. In line with these observations it has been shown that ING4 nuclear level is reduced in myeloma cells as compared to normal plasma cells, and that ING4 regulates IL-8 and OPN production by myeloma cells both in normoxia and hypoxia [95]. In addition, ING4 has a suppressive effect on HIF-1α activity in myeloma cells because blocking ING4 in myeloma cells increases both HIF-1α activity and the expression of its target gene NIP-3 [95].…”

“…Studies indicate that myeloma cells and BM stromal cells [94,95] directly produce IL-8, and elevated BM levels of IL-8 have been demonstrated in MM patients [95]. Tumor cell expression of IL-8 has been linked to the metastatic potential of many solid tumors [96,97].…”

“…Although HIF-1α seems to be a major regulator of the proangiogenic profile of myeloma cells and MM-induced angiogenesis, more recently the potential involvement of other genes in the production of pro-angiogenic factors by myeloma cells has been elucidated [95,116].…”

Microvesicle-delivery miR-150 promotes tumorigenesis by up-regulating VEGF, and the neutralization of miR-150 attenuate tumor development

“…It is well known that ING4 is a tumor suppressor for it intervenes the activity of hypoxia inducible factor (HIF) which has an important positive role in angiogenesis and tumorigenesis. HIF promote tumor angiogenesis by inducing VEGF and other factors (Ozer et al, 2005;Colla et al, 2007). Thus, the up-regulation of VEGF by miR-150 may be mediated by ING4 (Brahimi-Horn and Pouyssegur, 2006).…”