Center for Prostate Disease Research, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA
While the majority of carcinogenesis studies have relied on
the use of rodent cells in culture, experimental models to define
the role of carcinogenic agents in the development of cancers
must be established by using a variety of human cells. Unlike
rodent cells, normal human cells in culture rarely undergo spontaneous
transformation and have generally proven to be resistant to
neoplastic transformation by carcinogens. Remarkable progress
has been made during the past decade in human cell transformation
systems. Malignant transformation of human cells in culture
has been achieved by a stepwise process: immortalization and
conversion of the immortalized cells to tumorigenic cells. One
of the critical initial events in the progression of normal
human cells to tumor cells is the escape from cellular senescence,
with few exceptions; normal human cells require immortalization
to provide a practical system for carcinogenesis studies. Different
cell types require different conditions and transforming agents
to achieve a useful cell line. The current state of the art
in immortalization of human cells will be presented.
