Upregulation of nemo-like kinase is an independent prognostic factor in colorectal cancer.
OBJECTIVE
To investigate the expression and oncogenic role of nemo-like kinase (NLK) in colorectal cancer.


METHODS
Expression of NLK protein was assessed by immunohistochemistry in tissue specimens from 56 cases of normal colorectal mucosa, 51 cases of colorectal adenoma, and 712 cases of colorectal cancer. In addition, NLK expression was knocked down using a lentivirus carrying NLK small hairpin RNA in colorectal cancer cells. Cell viability methylthiazoletetrazolium assays, colony formation assays, flow cytometry cell cycle assays, Transwell migration assays, and gene expression assays were performed to explore its role on proliferation and migration of colorectal cancer.


RESULTS
Expression of NLK protein progressively increased in tissues from the normal mucosa through adenoma to various stages of colorectal cancer. Overexpression of NLK protein was associated with advanced tumor-lymph node-metastasis stages, poor differentiation, lymph node and distant metastases, and a higher recurrence rate of colorectal cancer (P < 0.05). Multivariate analyses showed that NLK expression was an independent prognostic factor to predict overall survival (hazard ratio 2.57, 95% confidence interval: 1.66-3.98; P < 0.001) and disease-free survival (hazard ratio 1.96, 95% confidence interval: 1.40-2.74: P < 0.001) of colorectal cancer patients. Furthermore, knockdown of NLK expression in colorectal cancer cell lines reduced cell viability, colony formation, and migration, and arrested tumor cells at the G0/G1 phase of the cell cycle. At the gene level, knockdown of NLK expression inhibited matrix metalloproteinase-2 expression in colorectal cancer cells.


CONCLUSIONS
NLK overexpression is an independent prognostic factor in colorectal cancer and knockdown of NLK expression inhibits colorectal cancer progression and metastasis.
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Wei
W
Zhang
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Jian
J
He
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Yan
Y
Du
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Xian-Hua
XH
Gao
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Yan
Y
Liu
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Qi-Zhi
QZ
Liu
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Wen-Jun
WJ
Chang
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Guang-Wen
GW
Cao
Wei Zhang, Jian He, Xian-Hua Gao, Qi-Zhi Liu, Chuan-Gang Fu, Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Chuan-Gang
CG
Fu
D018256:Adenomatous Polyps / Q000201:enzymology* / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000601:surgery; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002277:Carcinoma / Q000201:enzymology* / Q000235:genetics / Q000401:mortality / Q000556:secondary / Q000601:surgery; D059447:Cell Cycle Checkpoints; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D003111:Colonic Polyps / Q000201:enzymology* / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000601:surgery; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D018572:Disease-Free Survival; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D057809:HEK293 Cells; D019073:HT29 Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008207:Lymphatic Metastasis; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012307:Risk Factors; D014162:Transfection; D016896:Treatment Outcome; D015854:Up-Regulation
D014408:Biomarkers, Tumor; D047908:Intracellular Signaling Peptides and Proteins; C470551:NLK protein, human; D017346:Protein Serine-Threonine Kinases
Colorectal cancer; Gene regulation; Nemo-like kinase; Prognosis