Epidermal Growth Factor Receptor Expression Identifies Functionally and Molecularly Distinct Tumor-Initiating Cells in Human Glioblastoma Multiforme and Is Required for Gliomagenesis

Mazzoleni, Stefania; Politi, Letterio S.; Pala, Mauro; Cominelli, Manuela; Franzin, Alberto; Sergi, Lucia Sergi; Falini, Andrea; Palma, Michele De; Bulfone, Alessandro; Poliani, Pietro Luigi; Galli, Rossella

doi:10.1158/0008-5472.can-10-2353

Cited by 199 publications

(178 citation statements)

References 48 publications

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“…Because the biological effects driven by estrogen receptor (ER) are directly involved in breast cancer development and progression, 40,41 and epidermal growth factor receptor (EGFR) is overexpressed in CSCs of several tumors, [42][43][44] we asked whether growth factors that were known to contribute to tumorigenesis, such as EGF and 17b-estradiol (E2), mediate their antiapoptotic effects by modulating BAD phosphorylation in CSCs. Although LY294002 significantly reduced the CSC frequency in prostate cancer cells, EGF restored this frequency by protecting from LY-induced apoptosis (Figure 4a).…”

Section: Resultsmentioning

confidence: 99%

Targeting proapoptotic protein BAD inhibits survival and self-renewal of cancer stem cells

Sastry

Al-Muftah

et al. 2014

Cell Death Differ

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Emerging evidence suggests that the resistance of cancer stem cells (CSC) to many conventional therapies is one of the major limiting factors of cancer therapy efficacy. Identification of mechanisms responsible for survival and self-renewal of CSC will help design new therapeutic strategies that target and eliminate both differentiated cancer cells and CSC. Here we demonstrated the potential role of proapoptotic protein BAD in the biology of CSC in melanoma, prostate and breast cancers. We enriched CD44 þ /CD24 À cells (CSC) by tumorosphere formation and purified this population by FACS. Both spheres and CSC exhibited increased potential for proliferation, migration, invasion, sphere formation, anchorage-independent growth, as well as upregulation of several stem cell-associated markers. We showed that the phosphorylation of BAD is essential for the survival of CSC. Conversely, ectopic expression of a phosphorylation-deficient mutant BAD induced apoptosis in CSC. This effect was enhanced by treatment with a BH3-mimetic, ABT-737. Both pharmacological agents that inhibit survival kinases and growth factors that are involved in drug resistance delivered their respective cytotoxic and protective effects by modulating the BAD phosphorylation in CSC. Furthermore, the frequency and self-renewal capacity of CSC was significantly reduced by knocking down the BAD expression. Consistent with our in vitro results, significant phosphorylation of BAD was found in CD44 þ CSC of 83% breast tumor specimens. In addition, we also identified a positive correlation between BAD expression and disease stage in prostate cancer, suggesting a role of BAD in tumor advancement. Our studies unveil the role of BAD in the survival and self-renewal of CSC and propose BAD not only as an attractive target for cancer therapy but also as a marker of tumor progression.

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Section: Resultsmentioning

confidence: 99%

Targeting proapoptotic protein BAD inhibits survival and self-renewal of cancer stem cells

Sastry

Al-Muftah

et al. 2014

Cell Death Differ

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“…EGFR expression is a marker of proliferating neural stem cells and progenitors (26). Indeed, the presence of the receptor in the membrane marks a highly aggressive subpopulation of GBMCSCs (27) and EGFR signaling has been linked to the expression of stem cell features in GBMs (28). More recently, it has been demonstrated that EGFR is downregulated upon GBM differentiation and that EGFR signaling blockade leads to decreased tumorigenic and stem cell-like potential of GBM neurospheres (29).…”

Section: Discussionmentioning

confidence: 99%

Preclinical Test of Dacomitinib, an Irreversible EGFR Inhibitor, Confirms Its Effectiveness for Glioblastoma

Zahonero

Aguilera

Ramírez-Castillejo

et al. 2015

Molecular Cancer Therapeutics

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Glioblastomas (GBM) are devastating tumors in which there has been little clinical improvement in the last decades. New molecularly directed therapies are under development. EGFR is one of the most promising targets, as this receptor is mutated and/or overexpressed in nearly half of the GBMs. However, the results obtained with first-generation tyrosine-kinase inhibitors have been disappointing with no clear predictive markers of tumor response. Here, we have tested the antitumoral efficacy of a second-generation inhibitor, dacomitinib (PF299804, Pfizer), that binds in an irreversible way to the receptor. Our results confirm that dacomitinib has an effect on cell viability, self-renewal, and proliferation in EGFR-amplified AE EGFRvIII GBM cells. Moreover, systemic administration of dacomitinib strongly impaired the in vivo tumor growth rate of these EGFR-amplified cell lines, with a decrease in the expression of stem cell-related markers. However, continuous administration of the compound was required to maintain the antitumor effect. The data presented here confirm that dacomitinib clearly affects receptor signaling in vivo and that its strong antitumoral effect is independent of the presence of mutant receptor isoforms although it could be affected by the PTEN status (as it is less effective in a PTEN-deleted GBM line). Dacomitinib is being tested in second line for EGFR-amplified GBMs. We hope that our results could help to select retrospectively molecular determinants of this response and to implement future trials with dacomitinib (alone or in combination with other inhibitors) in newly diagnosed GBMs. Mol Cancer Ther; 14(7); 1548-58. Ó2015 AACR.

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“…CICs were isolated in vitro by the mechanical processing of primary tumor tissues (#1076, 1247, 111011, and 14583) and were cultured in the form of spheres (colon-spheres) in the presence of stem cell-permissive medium (DMEM/F12) containing 20 ng/ml epidermal growth factor and 50 ng/ml fibroblast growth factor 2 (PeproTech, Rocky Hill, NJ), as previously described (17). Part of the primary cell dissociation of CRC tissues was cultured in the presence of RPMI 1640 supplemented with 10% FBS (Biowittaker, Lonza, Treviglio, Italy), hereafter denominated FBS tumor cells (#1076, 1247, 111011, 1039, and 20299), and representing the differentiated tumor cell counterparts, as previously described (10,17,18); these cell lines were used in parallel with CICs.…”

Section: Tissues and Cellsmentioning

confidence: 99%

“…Part of the primary cell dissociation of CRC tissues was cultured in the presence of RPMI 1640 supplemented with 10% FBS (Biowittaker, Lonza, Treviglio, Italy), hereafter denominated FBS tumor cells (#1076, 1247, 111011, 1039, and 20299), and representing the differentiated tumor cell counterparts, as previously described (10,17,18); these cell lines were used in parallel with CICs. Additional CIC lines (#1, 2, and 3) isolated from primary CRC patients have been previously characterized (19).…”

Section: Tissues and Cellsmentioning

confidence: 99%

“…CICs cultured in vitro as serum-free-derived spheres, following mechanical dissociation of the spheres to single cells by extensive pipetting (17), were plated in six-well culture plates in the presence of DMEM plus 5% of FBS, representing the differentiating agent, as previously described by Vermeulen and coworkers (20) for 7-10 d to induce the cells to acquire the adherencedependent growth and the differentiated phenotype. …”

Section: In Vitro Differentiation Assaymentioning

confidence: 99%

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Cancer-Initiating Cells from Colorectal Cancer Patients Escape from T Cell–Mediated Immunosurveillance In Vitro through Membrane-Bound IL-4

Volonté

Tomaso

Spinelli

et al. 2014

The Journal of Immunology

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Cancer-initiating cells (CICs) that are responsible for tumor initiation, propagation, and resistance to standard therapies have been isolated from human solid tumors, including colorectal cancer (CRC). The aim of this study was to obtain an immunological profile of CRC-derived CICs and to identify CIC-associated target molecules for T cell immunotherapy. We have isolated cells with CIC properties along with their putative non-CIC autologous counterparts from human primary CRC tissues. These CICs have been shown to display “tumor-initiating/stemness” properties, including the expression of CIC-associated markers (e.g., CD44, CD24, ALDH-1, EpCAM, Lgr5), multipotency, and tumorigenicity following injection in immunodeficient mice. The immune profile of these cells was assessed by phenotype analysis and by in vitro stimulation of PBMCs with CICs as a source of Ags. CICs, compared with non-CIC counterparts, showed weak immunogenicity. This feature correlated with the expression of high levels of immunomodulatory molecules, such as IL-4, and with CIC-mediated inhibitory activity for anti-tumor T cell responses. CIC-associated IL-4 was found to be responsible for this negative function, which requires cell-to-cell contact with T lymphocytes and which is impaired by blocking IL-4 signaling. In addition, the CRC-associated Ag COA-1 was found to be expressed by CICs and to represent, in an autologous setting, a target molecule for anti-tumor T cells. Our study provides relevant information that may contribute to designing new immunotherapy protocols to target CICs in CRC patients.

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Epidermal Growth Factor Receptor Expression Identifies Functionally and Molecularly Distinct Tumor-Initiating Cells in Human Glioblastoma Multiforme and Is Required for Gliomagenesis

Cited by 199 publications

References 48 publications

Targeting proapoptotic protein BAD inhibits survival and self-renewal of cancer stem cells

Targeting proapoptotic protein BAD inhibits survival and self-renewal of cancer stem cells

Preclinical Test of Dacomitinib, an Irreversible EGFR Inhibitor, Confirms Its Effectiveness for Glioblastoma

Cancer-Initiating Cells from Colorectal Cancer Patients Escape from T Cell–Mediated Immunosurveillance In Vitro through Membrane-Bound IL-4

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