[Expression and relocation of B23 in the process of rat liver cell hyperplasia and liver regeneration].
OBJECTIVE
To study the B23 expression and relocation in the process of liver regeneration at different time periods after partial hepatectomy (PH) on healthy rats, and to study the feasibility of using B23 as a proliferation marker.


METHODS
Eighteen rats underwent partial hepatectomy (PH). The regenerative liver tissues were obtained at day 1, 2, 3, 4,and 7 after PH. The expression of B23 in hepatocytes of the regenerative tissues was measured using monoclonal antibody against nucleophosmin/B23 by Western blot and immunohistochemistry. The expression of proliferate cell nuclear antigen (PCNA) in these cells were measured using monoclonal antibody against PCNA by both methods for comparison with that of B23.


RESULTS
Expression of B23 in the steady state of liver cells before PH was hardly detected by both methods. The increased expression of B23 in the regenerative liver cells was quantitatively changed like a parabolic curve at day 1 to days 7 after PH, with the peak expression of B23 at day 3 after PH. This quantitative variation of B23 expression was similar to that of PCNA expression. The variation of location of B23 in the regenerative liver cells was observed from nucleolus (G1-S phase) to nucleoplasm (S-G2 phase) and to cytoplasm and mitotic chromosome (M phase).


CONCLUSIONS
B23 expression is quantitatively increased and moves in location in the process of liver regeneration after PH. B23 may be regarded as a proliferation marker in liver regeneration and liver cell hyperplasia.
Cancer Hospital of Sun Yat-sen University, Guangzhou 510060, China.
Jingping
J
Yun
Chong Tsek
CT
Liew
Eng Qing
EQ
Chew
John Y H
JY
Chan
D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle; D054637:Dual-Specificity Phosphatases; D006965:Hyperplasia; D007150:Immunohistochemistry; D008099:Liver / Q000473:pathology*; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D017027:Protein Tyrosine Phosphatases / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar
D018809:Proliferating Cell Nuclear Antigen; C442320:DUSP5 protein, human; D054637:Dual-Specificity Phosphatases; D017027:Protein Tyrosine Phosphatases