Sažeci 2. Hrvatskog kongresa medicinske biokemije - Klinički zavod ...

Sažeci 2. Hrvatskog kongresa medicinske biokemije
POSTERSKI RADOVI
06/P8
DYNAMICS OF p53 PROTO-ONCOGENE EXPRESSION
DURING COMPENSATORY LIVER GROWTH IN MIČE
V. Montana, D. Verbanac, K. Pavelić 1 , Č. Milin, M. Petković 2 , B. Radošević-
Stasić , J. Laginja
Department of Biochemistrv and Department of Physiology, Medical Faculty,
University of Rijeka; Division of Molecular Medicine, Institute "Ruđer Bošković",
Zagreb
In the mammal, the liver is unique in its abilitv to regenerate
and restore its original function. Hepatocytes, which represent the
nucleus of regeneration enter the cell cycle as the transform from a
quiescent state (Go) to a prereplicative state (Gl). This is followed by
DNA synthesis (S) and mitosis (M) with cell division completing the
sequence. This process is mediated by hepatotrophic factors that conjointly
stimulate up-regulation of proto-oncogene expression with concurrent
and subsequent formation of proteins that are responsible for
growth control. Proto-oncogene products are integral to the cellular
signaling system and generally are very highly conserved through
evolution. Proto-oncogene expression after 2/3 hepatectomy in rats can
be divided into three phases: I) early (0 to 4); II) intermediate (8 to
14) and III) late (24 to 72 hours post-operation). In this work we followed
the dynamics of appearance of oncoprotein p53 in liver tissue,
after 1/3 partial hepatectomy (pHx) performed on male inbred, 2-3
months old BALB/C miče. Ali the results were established by immunohistochemical
staining of the slices of liver tissue. The proteins were
identified using specific monoclonal antibody. The obtained results
showed that p53 is present in the intact liver tissue as well as
during the compensatory liver growth. The appearance of p53 oncoprotein
after 1/3 partial hepatectomy in miče is characterized by three
waves: the first one: after 8 hours; the second one: after 72 - 96 hours;
and the third one: 15th day after operation.
144 BIOCHEMIA MEDICA god. 6, br. 1, 1996