1.Comparison Of Invasion By Human Microvascular Endothelial Cell Lines In Response To Vascular Endothelial Growth Factor (Vegf) And Basic Fibroblast Growth Factor (Bfgf) In A Three-Dimensional (3d) Cell Culture System
Chin Tat Ng ; Wai Kien Yip ; Norhafizah Mohtarrudin ; Heng Fong
The Malaysian Journal of Pathology 2015;37(3):219-225
Background: Immortalized human endothelial cells are widely used as in vitro models for debilitating
conditions such as cancer, cardiovascular and ocular diseases. Human microvascular endothelial
cell (HMEC-1) is immortalized via stable transfection with a gene encoding SV40 large antigen
whilst telomerase-immortalized human microvascular endothelial (TIME) cells is immortalized by
engineering the human telomerase catalytic protein (hTERT) into primary microvascular endothelial
cells. Here, we established a three-dimensional (3D) spheroid invasion assay with HMEC-1 and
TIME and compared the difference in their ability to invade through the collagen matrix in response
to exogenous growth factors, namely vascular endothelial growth factor (VEGF) and basic fibroblast
growth factor (bFGF). Methods: TIME and HMEC-1 spheroids were embedded in a collagen
matrix. The spheroids were stimulated with exogenous growth factors, namely VEGF (50ng/mL)
and bFGF (200ng/mL). Twelve points of invasion length from a spheroid was measured using image
analysis software, Image J. Three independent experiments were conducted and data was analysis
by GraphPad Instat software, version 3.05. Results: TIME spheroid invasion was 16.5 fold higher
with exogenous VEGF (50ng/mL) and bFGF (200ng/mL) treatment as compared to those cultured in
complete growth medium only. In contrast, no significant difference was observed between HMEC-1
spheroids stimulated with and without exogenous growth factors, VEGF and bFGF. Conclusions:
This is the first report on the establishment of a 3D-spheroid invasion assay with TIME cells. The
requirement of VEGF and bFGF for TIME spheroids invasion is a novel finding. In addition, this
assay offers an advantage over HMEC-1 for testing novel angiogenic agents since it is not affected
by endogenously secreted growth factors.
2.Characterization of tumorspheres generated from nasopharyngeal carcinoma cell line, TW06 and chemoresistance to docetaxel and oxaliplatin
Iris Goh Wen Li ; Yip Wai Kien ; Seow Heng Fong
Malaysian Journal of Medicine and Health Sciences 2015;11(2):9-20
In this study, tumorspheres were generated from TW06 nasopharyngeal carcinoma cell line and
examined their expression of putative cancer stem-like cell surface markers and drug sensitivity. The
rate of tumorsphere expansion from dissociated late passage TW06 tumorspheres (≥ passage 15) was
higher than that from parental cells and dissociated 10-day-old (passage 0) tumorspheres. The expression
of CD24 surface marker was lost in the generation of tumorspheres and the loss was reversible after
differentiating the tumorspheres in monolayer culture conditions. Drug sensitivity assay showed that late
passage tumorspheres were resistant to docetaxel and oxaliplatin treatment. Our data suggest that serially
passaged tumorspheres possess the characteristics of CSCs that render them a suitable preclinical in
vitro model for evaluating anticancer drug efficacy and elucidating the underlying mechanisms of drug
resistance.
Neoplastic Stem Cells
;
Nasopharyngeal carcinoma