Expression of USP22 and Survivin is an indicator of malignant behavior in hepatocellular carcinoma.
Hepatocellular carcinoma (HCC) is the most common primary malignant liver tumor type, ranking as the third leading cause of all cancer-related deaths in the world. The post-surgical 5-year survival rate is low, largely due to the high recurrence rate. Therefore, the identification of target molecules that control the biological characteristics of HCC is of great importance. Ubiquitin-specific protease 22 (USP22) is a newly discovered deubiquitinating enzyme and is a cancer stem cell marker that plays a role in tumorigenesis, therapy resistance and cell cycle progression. Survivin is a member of the inhibitor of apoptosis protein (IAP) family and is known to function either as an inhibitor for apoptosis or as a regulator of cell division. Levels of survivin are correlated with the aggressiveness of tumors and a poor prognosis in various cancers including HCC. In the present study, we examined the USP22 expression and its association with survivin expression and clinicopathological features in HCC. First, we examined the expression of USP22 and survivin in 151 HCC cases by immunohistochemistry. High expression of USP22 and survivin was frequently observed in HCC cases, in comparison with normal adjacent liver tissues. Expression of USP22 and survivin was well correlated with malignant behavior including tumor size, stage and differentiation in HCC cases. Importantly, HCC patients with high expression of USP22 and survivin showed poor prognosis. USP22 expression was well correlated with survivin expression in HCC cases. This correlation was confirmed in HCC cell lines and tissues by RT-PCR and western blot analysis. Next, to investigate the biological role of USP22 in HCC, we examined the effect of USP22 knockdown on the cell growth and the expression of cell cycle-related protein including survivin in HCC cells. USP22 siRNA suppressed cell growth. Moreover, USP22 siRNA decreased survivin expression together with upregulation of CDK inhibitor, p21 and downregulation of cyclin B. These findings suggest that USP22 may be involved in HCC progression in cooperation with survivin. We suggest that USP22 can be useful as a new prognostic marker and therapeutic target in HCC patients.
Department of Hepatobiliary Surgery, Guilin Medical University, Affiliated Hospital, Guilin, Guangxi 541001, P.R. China.
Bo
B
Tang
Department of Hepatobiliary Surgery, Guilin Medical University, Affiliated Hospital, Guilin, Guangxi 541001, P.R. China.
Xingsi
X
Liang
Department of Pathology, the Affiliated Hospital, Guilin Medical University, Guilin, Guangxi 541001, P.R. China.
Fang
F
Tang
Department of Hepatobiliary Surgery, Guilin Medical University, Affiliated Hospital, Guilin, Guangxi 541001, P.R. China.
Jing
J
Zhang
Department of Pathology and Physiopathology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Sien
S
Zeng
Department of Pathology and Physiopathology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Shengjian
S
Jin
Department of Pathology and Physiopathology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Lihua
L
Zhou
Department of Oral Molecular Pathology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8504, Japan.
Yasusei
Y
Kudo
Department of Pathology and Physiopathology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Guangying
G
Qi
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D045744:Cell Line, Tumor; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D007150:Immunohistochemistry; D051034:Inhibitor of Apoptosis Proteins / Q000032:analysis / Q000096:biosynthesis*; D008113:Liver Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077022:Survivin; D013869:Thiolester Hydrolases / Q000032:analysis / Q000096:biosynthesis*; D014162:Transfection; D043222:Ubiquitin Thiolesterase; D055815:Young Adult
C107489:BIRC5 protein, human; D014408:Biomarkers, Tumor; D051034:Inhibitor of Apoptosis Proteins; D034741:RNA, Small Interfering; D000077022:Survivin; D013869:Thiolester Hydrolases; D043222:Ubiquitin Thiolesterase; C527170:Usp22 protein, human