Integrin-linked kinase overexpression promotes epithelial-mesenchymal transition via nuclear factor-κB signaling in colorectal cancer cells.
OBJECTIVE
To investigate the effect of integrin-linked kinase (ILK) on proliferation, metastasis, and invasion of the colorectal cancer cell line SW480.


METHODS
In this study, the colorectal cancer cell line SW480 was stably transfected with ILK plasmids, and small interfering RNA (siRNA) was used to knockdown expression of nuclear factor (NF)-κB/p65. Methylthiazole tetrazolium (MTT) assay was performed to measure proliferation, and the wound healing migration assay and matrigel invasion assay were used to test the metastasis and invasion ability of SW480 cells. To explore the epithelial-mesenchymal transition (EMT) process, embryonic development, and the invasion and metastasis of tumors, the protein level of E-cadherin, vimentin, snail, and slug was detected by western blot. Immunofluorescence was also used to detect E-cadherin expression. Western blot was used to determine the level of phosphorylated-inhibitor of kappa B (IκB)a, inhibitor of gamma B (IγB)a, and nuclear factor kappa B (NF-κB) expressions and to explore the ILK signaling pathway.


RESULTS
Western blot results revealed that ILK expression significantly increased when ILK was overexpressed in SW480 cells (P < 0.05). Proliferation, metastasis, and invasion ability were improved in the vector-ILK group compared to the vector group (P < 0.05). Immunofluorescence results revealed that E-cadherin fluorescence intensity decreased after ILK was overexpressed (P < 0.05). Western blot results revealed that the protein expression of E-cadherin was reduced, while vimentin, snail, and slug were upregulated when ILK was overexpressed in SW480 cells (P < 0.05). In order to determine the role of the NF-κB signaling pathway in ILK overexpression promoted EMT occurrence, we overexpressed ILK in SW480 cells and found that levels of NF-κB/p65 and cytoplasmic phosphorylated-IκBa were increased and that cytoplasmic IкBa levels were decreased compared to the control group (P < 0.05). Furthermore, NF-κB/p65 knockout revealed that E-cadherin was increased in the overexpressed ILK group.


CONCLUSIONS
ILK overexpression improved the proliferation, metastasis, and invasion ability of SW480 cells, and this effect may be mediated by the NF-κB signaling pathway.
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Hong
H
Shen
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Jun-Li
JL
Ma
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Yan
Y
Zhang
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Gan-Lu
GL
Deng
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Yan-Ling
YL
Qu
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Xiao-Ling
XL
Wu
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Jing-Xuan
JX
He
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Sai
S
Zhang
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
Shan
S
Zeng
D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D004790:Enzyme Induction; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009362:Neoplasm Metastasis; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000235:genetics; D034622:RNA Interference; D015398:Signal Transduction; D013997:Time Factors; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D000099200:Scaffold Protein ILK
D017346:Protein Serine-Threonine Kinases; D051996:Transcription Factor RelA; D000099200:Scaffold Protein ILK; C498143:RELA protein, human
Colorectal cancer; Epithelial-mesenchymal transition; Integrin-linked kinase; Nuclear factor-κB; Overexpression