[Expression and regulation of p16 in osteosarcoma].
OBJECTIVE
To study the expression and regulation of p16 and related factors in osteosarcoma.


METHODS
The levels of p16 protein and related factors were explored by Western blot analysis in 12 cases of osteosarcoma tissues and in cells of different phases of osteosarcoma cell line OS732. The status of p16 protein in osteosarcoma cells was revealed by immunofluorescence analysis.


RESULTS
p16 protein was detected in 10 of 12 osteosarcoma tissues. pRb was found in all of the specimens, but 8 of them were hyperphosphorylated. p16 protein was the least in G1 phase. Localized in cytoplasm during G1 phase, p16 protein gathered around nuclear envelope in S phase and entered the nucleus in G2 phase.


CONCLUSIONS
The expression rate of p16 protein was 83.3% in osteosarcoma tissues. The expression of p16 protein was unable to inhibit the phosphorylation of pRb in most osteosarcomas; p16 protein was extremely low in G1 phase, presumably it was sufficient to inhibit the phosphorylation of pRb, causing abnormal proliferation of the cells.
Shi
X
X
Department of Orthopeadics, First Hospital, Beijing Medical University, Beijing 100034.
Ma
Z
Z
Wang
D
D
Liang
Y
Y
Li
H
H
Wang
J
J
D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002648:Child; D019938:Cyclin D1 / Q000096:biosynthesis; D051358:Cyclin-Dependent Kinase 4; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis*; D018844:Cyclin-Dependent Kinases / Q000096:biosynthesis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000378:metabolism* / Q000473:pathology; D011518:Proto-Oncogene Proteins; D016160:Retinoblastoma Protein / Q000096:biosynthesis
D019941:Cyclin-Dependent Kinase Inhibitor p16; D011518:Proto-Oncogene Proteins; D016160:Retinoblastoma Protein; D019938:Cyclin D1; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases