Targeted disruption of Nemo-like kinase inhibits tumor cell growth by simultaneous suppression of cyclin D1 and CDK2 in human hepatocellular carcinoma.
The Wnt/beta-catenin signaling pathway regulates various aspects of development and plays important role in human carcinogenesis. Nemo-like kinase (NLK), which is mediator of Wnt/beta-catenin signaling pathway, phosphorylates T-cell factor/lymphoid enhancer factor (TCF/LEF) factor and inhibits interaction of beta-catenin/TCF complex. Although, NLK is known to be a tumor suppressor in Wnt/beta-catenin signaling pathway of colon cancer, the other events occurring downstream of NLK pathways in other types of cancer remain unclear. In the present study, we identified that expression of NLK was significantly up-regulated in the HCCs compared to corresponding normal tissues in five selected tissue samples. Immunohistochemical analysis showed significant over-expression of NLK in the HCCs. Targeted-disruption of NLK suppressed cell growth and arrested cell cycle transition. Suppression of NLK elicited anti-mitogenic properties of the Hep3B cells by simultaneous inhibition of cyclinD1 and CDK2. The results of this study suggest that NLK is aberrantly regulated in HCC, which might contribute to the mitogenic potential of tumor cells during the initiation and progression of hepatocellular carcinoma; this process appears to involve the induction of CDK2 and cyclin D1 and might provide a novel target for therapeutic intervention in patients with liver cancer.
Department of Pathology, Microdissection Genomics Research Center, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
Kwang Hwa
KH
Jung
Jeong Kyu
JK
Kim
Ji Heon
JH
Noh
Jung Woo
JW
Eun
Hyun Jin
HJ
Bae
Hong Jian
HJ
Xie
Young Min
YM
Ahn
Won Sang
WS
Park
Jung Young
JY
Lee
Suk Woo
SW
Nam
D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism*; D051357:Cyclin-Dependent Kinase 2 / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D035582:Transcription Factor TFIIIA / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; D026901:Membrane Transport Proteins; C409460:OPTN protein, human; D035582:Transcription Factor TFIIIA; D019938:Cyclin D1; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2