ABSTRACT
Complex molecular and cellular mechanisms exist to protect cells against tumor formation
and to protect the entire organism against further development and spread of established
tumors. The p53 tumor suppressor gene controls the cell cycle through at least two
mechanisms, namely, mitotic arrest and apoptosis. Human hepato-cellular carcinomas
(HCCs) are often found to have mutant p53, or sometimes may have dysfunctional p53
as a result of its being bound by viral or cellular proteins. Another mechanism of
host response is the production of transforming growth factor β1, which acts on receptors
in normal hepatocytes to cause inhibition of DNA synthesis; abnormalities of transforming
growth factor β1 have been documented in HCCs, but their biologic significance is
unclear. Other host defense mechanisms include cellular responses to the tumor and
the proliferation of substances with anticoagulant properties.
KEY WORDS
cytotoxic T lymphocytes - LAK cells - p53 - thrombomodulin - transforming growth factor
β
