The Development and Applications of a Dual Optical Imaging System for Studying Glioma Stem Cells.

Po-An Tai,Thanh-Tuan Huynh,Li Wei,Ya-Ting Wen,Alexander T H Wu,Michael Hsiao,Yen-Lin Liu,Chien-Min Lin

doi:10.1177/1536012119870899

Abstract

Glioblastoma multiforme represents one of the deadliest brain tumor types, manifested by a high rate of recurrence and poor prognosis. The presence of glioma stem cells (GSCs) can repopulate the tumor posttreatment and resist therapeutics. A better understanding of GSC biology is essential for developing more effective interventions. We established a CD133 promoter-driven dual reporter, expressing green fluorescent protein (GFP) and firefly luciferase (CD133-LG), capable for in vitro and in vivo imaging of CD133+ GSCs. We first demonstrated the reporter enabled in vitro analyses of GSCs. DBTRG-05MG (Denver Brain Tumor Research Group 05) carrying CD133-LG (DBTRG-05MG-CD133-LG) system reported increased GFP/luciferase activities in neurospheres. Additionally, we identified and isolated CD133+/GFP+ cells with increased tumorigenic properties, stemness markers, Notch1, β-catenin, and Bruton’s tyrosine kinase (Btk). Furthermore, prolonged temozolomide (TMZ) treatment enriched GSCs (reflected by increased percentage of CD133+ cells). Subsequently, Btk inhibitor, ibrutinib, suppressed GSC generation and stemness markers. Finally, we demonstrated real-time evaluation of anti-GSC function of ibrutinib in vivo with TMZ-enriched GSCs. Tumorigenesis was noninvasively monitored by bioluminescence imaging and mice that received ibrutinib showed a significantly lower tumor burden, indicating ibrutinib as a potential GSC inhibitor. In conclusion, we established a dual optical imaging system which enables the identification of CD133+ GSCs and screening for anti-GSC drugs.

Highlights

Glioma represents the most common type of brain cancer and glioblastoma multiforme (GBM) as the most prevalent and malignant subtypes of glioma.[1,2] Even with aggressive interventions such as surgery, radiation, chemotherapy, and targeted therapeutics, the median survival for patients with GBM is estimated to be 12 to 15 months.[3,4] Accumulating evidence has indicated that the presence of glioma stem cells (GSCs) represents as one of the key attributes to the malignant phenotypes of GBM
We showed that CD133þ GBM cells were associated with an increased level of Bruton’s tyrosine kinase (Btk) and increased the malignant properties of GBM cells such as increased resistance against chemotherapeutic agent, TMZ, and increased the generation of GSCs.[15]
Glioblastoma multiforme is one of the most malignant cancer types and despite advancement in therapeutics development, GBM remains a challenging tasks in the clinics

Summary

Introduction

Glioma represents the most common type of brain cancer and glioblastoma multiforme (GBM) as the most prevalent and malignant subtypes of glioma.[1,2] Even with aggressive interventions such as surgery, radiation, chemotherapy, and targeted therapeutics, the median survival for patients with GBM is estimated to be 12 to 15 months.[3,4] Accumulating evidence has indicated that the presence of glioma stem cells (GSCs) represents as one of the key attributes to the malignant phenotypes of GBM. The identification and isolation of GSCs still remain a challenging tasks both experimentally and clinically.

Methods

Results

Conclusion