(64b) Enrichment and Characterization of the Cancer Stem Cell (CSC) Fraction From PC3 Prostate Cancer Cell Line Cultures

Enrichment and characterization of the Cancer
Stem Cell (CSC) fraction from PC3 prostate cancer cell line cultures

Roberto Portillo Lara¹
and Mario Moises Alvarez^1,2

(1) Centro de Biotecnologia-FEMSA at Tecnologico de
Monterrey

Av.
Eugenio Garza Sada 2501 sur. Monterrey, NL. Mexico

(2) Escuela de Biotecnologia y Salud at Tecnologico de
Monterrey

Av.
Morones Prieto 3000 pte. Monterrey, NL. Mexico

The main goal of my
work is the characterization of cancer stem cells (CSCs) induced and isolated
from the PC3 prostate cancer cell line.

The Cancer Stem Cell
hypothesis postulates that the small fraction of cancerous stem –like
cells (CSCs) present in solid tumors are responsible for the origin and
propagation of the disease. A vast amount of experimental evidence supports
this argument. In recent years several groups worldwide have achieved the
isolation of CSCs from different types of solid cancers and leukemias.
However the percentage in which these cells are present within tumorous tissue
is extremely low. Moreover, the difficulty of purifying a single cell type from
a tissue biopsy has led to the search for reliable models that allow the
expansion and study of these particular cells. One of
these approaches is the use of established cell lines. The identification of a
subpopulation of cells, within a given cell line, expressing a phenotype
similar to the one observed in CSCs isolated from patients samples has already
been demonstrated previously. However the purification yields are extremely low
and the establishment of a definitive cell culture protocol is still work in
progress.

The isolation of cells
expressing the CD44⁺/α2β1^hi/CD133⁺ phenotype (which corresponds
to the one observed in CSCs obtained from biopsies) from a PC3 cell line
cultured under standard conditions, yields a
percentage of 0.1 positive events when analyzed via flow cytometry
(this is consistent with the information available in the literature). With the
implementation of a simple protocol, not previously reported, it is possible to
increase this percentage up to 5 percent. In addition to this, we have conducted
a protocol of gene expression profiling of PC3 cells cultured with the standard
and the novel protocol through distinct points in time and at the end point of
culture. This characterization was carried out using the nCounter
NanoString system. This technology allows us to
assess the levels of expression of a curated panel of 250 genes simultaneously.
This type of characterization presents us with a rich panorama of the transcriptional
level in these CSCs both at the end point of the experiment and through the
process of induction. This information could provide a better understanding of
the mechanisms of cell development that are key in CSC's propagation as well as
point us to the identification of novel, highly specific therapeutic targets.