Stem Cells in Gliomas

Review Article

J Stem Cells Res, Rev & Rep. 2014;1(2): 1009.

Stem Cells in Gliomas

Assimakis Assimakopoulos1, Konstantinos Polyzoidis1,2 and Athanassios P Kyritsis1,3*

1Neurosurgical Research Institute, University of Ioannina, Ioannina, Greece

2Department of Neurosurgery, Aristotle University of Thessaloniki, Thessaloniki, Greece

3Department of Neurology, University of Ioannina, Ioannina, Greece

*Corresponding author:Athanassios P Kyritsis, Neurosurgical Research Institute, University Campus Ioannina 45500, Greece

Received: Aug 20, 2014; Accepted: September 16, 2014; Published: September 16, 2014


Gliomas are central nervous system tumors exhibiting marked cellular heterogeneity, invasiveness and resistance to any therapeutic intervention. Experimental evidence suggests that most of these properties of gliomas are due to the presence of glial stem cells within the gliomas. Markers of glioma stem cells include Nestin, CD133 and CD15. The anatomic location of stem cells within gliomas is predominantly the perivascular areas. Glioma patients with high percentage of glial stem cells have poor survival. Although eradication of the glioma stem cells could extend survival it is difficult to succeed due to their high resistance to therapy. Apart from the glioma stem cells, normal neural stem cells that can be induced from pluripotential stem cells may be used therapeutically for gliomas as carriers for various antitumor agents due to their tropism for neural tissue, if their safety can be attained.

Keywords: Stem cells; Glioma; Brain tumor


Gliomas are central nervous system (CNS) tumors of glial origin, exhibiting a profound cellular heterogeneity with tumor cells showing various degrees of differentiation, and genetic heterogeneity with dissimilar gene alterations in neighbourhood cells of the same tumor [1]. This heterogeneity could be due to possible origin of glioma from neural stem cells (NSCs) which after pre-existing or acquired genetic abnormalities drive the NSCs to malignant transformation and formation of glioma stem cells [2]. Glioma stem cells exhibit increased invasiveness, angiogenesis and resistance to therapeutic interventions [3-5]. These glioma stem cells are eventually responsible for tumor malignancy, growth and recurrence [6].

Normal stem cells are capable of infinite proliferation like cancer cells. Apart to the well-known hematopoietic stem cells from bone marrow, stem cell stores exist in other adult tissues. Thus, subcutaneous fat and dermis consist of accessible sources for obtaining stem cells, with minimal discomfort to the patient [7]. Stem cells niche denotes the anatomic location or microenvironment where stem cells are located, and this microenvironment interacts with the stem cells to regulate various cell functions [8]. Recent evidence suggests that human glioma niches are localized in the perivascular areas within gliomas [9].

Study of both normal stem cells and glioma stem cells are important during therapy of gliomas: Normal stem cells may be used during treatment for gliomas, mainly as vehicles to transfer various therapeutic agents to the tumor; study of glioma stem cells is also important to assess the tumor behavior, response to treatment and prognosis.

Stem Cell Markers

Glioma stem cells and NSCs co-express similar markers essential for similar functions in both types of cells (Table 1) [10]. Markers of glioma stem cells include Nestin, CD133 and CD15 [11]. Nestin, is a type-VI intermediate filament that is briefly expressed in glioma tissue during brain development. A study in 70 patients with gliomas that had surgery showed that nestin was expressed in astrocytic gliomas and correlated with the degree of malignancy [12]. Similarly, another immunohistochemichal study in 87 primary CNS tumors showed that nestin was expressed in 95.8% of gliomas with higher expression in malignant tumors and inversely correlated with patient survival. Interestingly, the immunohistochemical staining of nestin in a xenograft model demonstrated its location mainly in the invasive tumor cells at the tumor periphery rather than tumor center [13].

Citation: Assimakopoulos A, Polyzoidis K and Kyritsis AP. Stem Cells in Gliomas. J Stem Cells Res, Rev & Rep. 2014;1(2): 1009. ISSN:2381-9073