ABSTRACT
The promyelocytic leukemia (PML) protein is an important part of the PML nuclear bodies (PML-NBs) structure.PML protein is crucial for the assembly of PML-NBs and recruits more than 30 different proteins, including DAXX, ATRX, and small ubiquitin-like molecules involving SUMO to the PML-NBs region.Increased evidence has emerged that a number of different proteins is involved in regulating PML activities by post-translational modifications, such as SUMO modification, ubiquitination and phosphorylation.Here, we review recent studies on the combination of PML and different proteins in the process of apoptosis, replicative senescence and DNA damage response.
ABSTRACT
Objective To observe the PML protein expression of hepatocellar carcinoma tissue and cells lines and As 2 O3 regulate its expression .Methods Immunohistochemistry was used to examine the PML protein expression of hepatocellar carcinoma tissue . Western blot analysis were used to observe PML protein expression of hepatocellar carcinoma tissue of 12 cases ,5 hepatocellar car-cinoma cell lines ,such as HuH7 ,HepG2 ,Hep3B ,SMMC-7721 ,MHC97H .Western blot analysis was used to detected the PML pro-tein expression of these hepatocellar carcinoma cell lines after 72-96 h treated with 0 .25 μg/mL of As2 O3 .Results Immunohisch-enmical staining showed that the PML protein was expressed in both cytoplasm and nucleus ,did not well-distributed in hepatocellar carcinoma cells .There was no significant differences of PML protein expressed among differently differentiated stages of hepatocel-lar carcinoma cells .Western blot analysis found that hepatocellar carcinoma tissues of 12 cases with hepatocellar carcinoma ex-pressed PML protein ,and there was significant difference of PML protein expressed among 12 cases suffer with hepatocellar carci-noma .hepatocellar carcinoma cell lines ,such as HuH7 ,HepG2 ,Hep3B ,SMMC-7721 and MHC97H all expressed PML protein ,and there was little difference of PML protein expressed among hepatocellar carcinoma cell lines .The PML protein expression of HuH7 ,HepG2 ,Hep3B ,SMMC-7721 and MHC97H cell after 72-96 h treated with 0 .25 μg/mL of As2O3 significant decreased . Conclusion Hepatocellar carcinoma tissue and cells may express PML protein ,and As2 O3 may regulate this protein expression as well .PML protein may be the target molecule of As2 O3 treating HCC .
ABSTRACT
BACKGROUND: Promyelocytic leukemia protein (PML) is a primary biliary cirrhosis (PBC)-specific autoantigen. Anti-PML antibody is analyzed using cultured cells with patient sera, however, PML expression has rarely been examined in liver tissues. METHODS: In the present study, PML expression was examined immunohistochemically in paraffin embedded liver needle biopsy specimens obtained from 20 cases of PBC, 10 cases of autoimmune cholangitis, 36 cases of autoimmune hepatitis and from 5 cases of noninflammatory livers. RESULTS: Variable PML immunopositivity was detected in the bile duct epithelial cells of 18 (90.0%) of 20 PBC cases and in all 10 cases (100.0%) of autoimmune cholangitis, whereas it was only present in 6 (16.7%) of 36 cases of autoimmune hepatitis (p<0.001). In contrast, hepatocyte PML immunopositivity was higher in autoimmune hepatitis (33/36 cases, 90.8%), than in PBC (10/20 cases, 50.0%) or autoimmune cholangitis (3/10 cases, 30.0%) (p<0.05). CONCLUSION: Our data indicate that the differential expression of PML is closely related to autoimmune liver diseases type, and suggest that the overexpression of PML protein in bile duct cells is associated with the development of autoantibodies in patients with PBC or autoimmune cholangitis. Furthermore, PML immunoreactivity may be useful for the diagnosis of autoimmune cholangitis and overlap syndrome.