418PD - Association between cancer stem cells and CD133+ blood vessels in glioblastoma multiforme

Date 29 September 2012
Event ESMO Congress 2012
Session CNS tumors
Topics Central Nervous System Malignancies
Presenter Jana Jaal
Authors J. Jaal1, M. Kase2, A. Minajeva3, K. Niinepuu3, S. Kase4, M. Vardja1, T. Asser5
  • 1Dept Of Radiotherapy And Oncological Therapy, Tartu University Hospital, Haematology and Oncology Clinic, Tartu/EE
  • 2North Estonia Medical Centre, Oncology and Haematology Clinic, Tallinn/EE
  • 3Faculty Of Medicine, University of Tartu, Tartu/EE
  • 4Nursing, Health Care College, Tartu/EE
  • 5Dept Of Neurosurgery, Tartu University Hospital, Tartu/EE

 

Abstract

Background

Glioblastoma multiforme (GBM) is the most aggressive type of brain tumor in adults. Histologically, GBMs are highly angiogenic. It has been suggested that GBM stem cells might support tumor vascularization. The aim of our study was to evaluate the association between CD133-positive (CD133+) cancer stem cells and blood vessels in GBM tissue.

Methods

Between Jan 2006 and Dec 2008, 42 patients (30-77 years) received postoperative radiotherapy and chemotherapy. Surgically excised GBM tissues were examined for CD133 expression prior anticancer therapy. After immunohistochemistry, the proportion of CD133+ stem cells (%), the number of CD133+ blood vessels (per microscopic field), and the staining intensity of endothelial CD133 expression (arbitrary score 0-3) were evaluated.

Results

The expression of CD133 was determined by 2 independent researchers whose results were in good accordance. The proportion of CD133+ GBM stem cells was 33% ± 24% (mean ± SD). GBM tissue consisted of both CD133+ and CD133- blood vessels. However, endothelial staining of CD133 was found in all types of GBM blood vessels, including small capillaries and microvascular proliferations. The number of CD133+ blood vessels per microscopic field was 1.4 ± 1.3 (mean ± SD), and the endothelial CD133 staining intensity 1.0 ± 0.5 (mean ± SD). A significant association was found between the proportion of CD133+ stem cells and the number of CD133+ blood vessels (p = 0.004). Also, a correlation between the number of CD133+ blood vessels and the endothelial CD133 staining intensity was detected (p < 0.001). Median survival time of the study group was 10.0 months (95% CI 9.0-11.0). In multivariate analysis, next to well-known prognostic factor Karnofsky Performance Score, the proportion of CD133+ GBM stem cells emerged as a significant independent predictor for longer overall survival (HR 2.0, 95% CI 1.0-3.8, p= 0.04).

Conclusion

In the present study, a significant association was found between CD133+ GBM stem cells and CD133+ blood vessels. Favourable CD133+ expression has to be taken into account in the strategies under preclinical or clinical development for GBM stem cell targeting. This work was supported by grant ETF8862 and Roche scientific grant.

Disclosure

J. Jaal: This work was partly supported by Roche scientific grant.

M. Kase: This work was partly supported by Roche scientific grant.

A. Minajeva: This work was partly supported by Roche scientific grant.

K. Niinepuu: This work was partly supported by Roche scientific grant.

S. Kase: This work was partly supported by Roche scientific grant.

M. Vardja: This work was partly supported by Roche scientific grant.

T. Asser: This work was partly supported by Roche scientific grant.