Downregulation of integrin-linked kinase inhibits epithelial-to-mesenchymal transition and metastasis in bladder cancer cells
Authors: Jun Zhu
Juan Gao
Junxia Chen
Xiangyang Pan
Luyu Zhang
Zheng Zhang
Journal: Cellular Signalling (2012)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Integrin-linked kinase (ILK); cancer; metastasis; oncogenic capacity; epithelial-mesenchymal transition (EMT)
Affiliations: Department of Cell Biology and Genetics, Chongqing Medical University,Chongqing 400016, China.

Abstract:  Integrin-linked kinase (ILK) is a multifunctional serine/threonine kinase in cytoplasm. Recent studies showed that cancer patients with increased ILK expression had low survival, poor prognosis and increased metastasis. Although the causes of ILK overexpression remain to be fully elucidated, accumulating evidence suggests that its oncogenic capacity derives from its regulation of several downstream targets that provide cells with signals that promote proliferation, survival and migration. However, the mechanisms underlying tumor metastasis by ILK is still not fully understood. Epithelial–mesenchymal transition (EMT) is a critical event of cancer cells that triggers invasion and metastasis. We recently reported that knockdown of ILK inhibited the growth and induced apoptosis in human bladder cancer cells. Therefore, we postulate that ILK might involve in EMT. Here we further investigate the function of ILK with RNA interference in bladder cancer cells. Knockdown of ILK impeded an EMT with low Vimentin, Snail, Slug and Twist as well as high E-cadherin expression in vivo and vitro. In addition, we found that knockdown of ILK inhibited cell proliferation, migration and invasion as well as changed cell morphology, adhesion and rearranged cytoskeleton in vitro. We also demonstrated that ILK siRNA inhibited phosphorylation of downstream signaling targets Akt and GSK3β, increased expression of nm23-H1, as well as reduced expression of MMP-2 and MMP-9 in vivo and vitro. Furthermore, downregulation of ILK could increase expression of Ribonuclease inhibitor (RI), an important acidic cytoplasmic protein with many functions. Finally, the effects of ILK siRNA on bladder cancer cell phenotype and invasiveness translate into suppression for tumorigenesis and metastasis in vivo. Taken together, our findings highlight that ILK signaling pathway plays a novel role in the development of bladder cancer through regulating EMT. ILK could be a promising diagnostic marker and therapeutic target for bladder cancer. 

Retracted: No

PubPeer comments:
 ![file] ![file] In the Fig.1B and Fig.1E ,the beta actin are identical, only different magnification. , 
 #1 By adjusting the brightness and contrast synchronously in Photoshop, it is clear that the internal reference bands of panel B and E are different. ![file] , 
 Dear Junxia Chen Instead of posting a Photoshop-adjusted version of these figures, why not simply post the original scans? , 
 #2 You can t alter the shape of the bands by adjusting the contrastion that much, instead, when adjust them appropriately, we can see they are so similar. Would you please show the original gel or data? ![file] , 
 #4 This article was a work we completed ten years ago. First, the internal reference bands of panel B and E in this figure were the same groups in the same cells. Second, the the first author recall that they came from two experiments. Then, several of us identified that the subtle characteristics of these bands are obviously different. , 
 #4 It s a screenshot of the PDF version of our article. ![file] , 
 #2 B E were commented by #1 as being probably from the same image source. Therefore, putting them side-by-side in Photoshop and adjusting u201csynchronouslyu201d their brightness contrast wonu2019t provide any additional information to help explain their similarity or difference. #5 You can post the  subtle characteristics of these bands are obviously different as a picture with those differences marked. This may help the readers get your explanation. #6 Your paper was pay-walled and no picture was available free of charge. The commenters who could post figures in the first place, e.g. #1 and #4, must already had the PDF of your paper; otherwise, they wouldn t be able to look at the figures. The screenshot was in a relatively lower resolution. , 
 Removed for duplicated post. , 
 #5 It seems reasonable if the actin controls in 1B and 1E **are** the same, with the two figures coming from the same gel, repeating the loading control for clarity. Is it possible that the first author has remembered wrongly? , 
 The following duplicates of beta-actin blots look like obvious. See the superimposed comparison. Fig 1B 1E As #9 pointed out, it might be for 1B and 1E to be the same image for the purpose of the study. but the author insisted that they were different images. ![file] Fig 2B and 2D These two look also very similar. ![file] , 
 Fig 5E. Two panels appear to overlap. Could the authors check? ![file] , 
 Figure 6B: Two sets of two panels appear to show an area of overlap. Shown with green and pink boxes. ![file] , 
 Figure 6C: Three panels appear to show an area of overlap, Just adjusted the lightness and darkness of the picture. Shown with red boxes. ![file] ,