EpCAM-claudin-tetraspanin-modulated ovarian cancer progression and drug resistance
Authors: Zehra Tavsan
H√ºlya Ayar Kayalƒ±
Journal: Cell Adhesion & Migration (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: EpCAM; Ovarian cancer; cell adhesion; claudins; palmitoylation
Affiliations: Chemistry Department, The Graduate School of Natural and Applied Science, Dokuz Eyl√ºl University, ƒ∞zmir, Turkey., Izmir Biomedicine and Genome Center, Izmir, Turkey., Chemistry Department, Science Faculty, Dokuz Eyl√ºl University, Izmir, Turkey., International Biomedicine and Genome Institute, Dokuz Eyl√ºl University, Izmir, Turkey.

Abstract:  Alterations of cell adhesion are involved in cancer progression, but the mechanisms underlying the progression and cell adhesion have remained poorly understood. Focusing on the complex between EpCAM, claudins and tetraspanins, we described a sequence of events by which of the molecules associate each other in ovarian cancer. The interactions between molecules were evaluated by immunoprecipitations and then immunoblotting. To identify the effects of complex formation on the ovarian cancer progression, the different types of ovarian cancer cell lines were compared. In this study, we report the identification of the EpCAM-claudin-4 or -7-CD82 complex in the ovarian cancer progression and metastasis in vitro. Additionally, we demonstrated palmitoylation and intra- or extra-cellular regions are critically required for the complex formation. These results represent the first direct evidence for the link between the dynamism of cell adhesion molecules and ovarian cancer progression. 

Retracted: No

PubPeer comments:
 Figure 6. * Orange boxes: The Western blot panels in Figure 6 look similar to panels in Figure 4 in another paper by the same authors, i.e. Tavsan and Kayali, Process Biochemistry (2020), DOI: 10.1016 j.procbio.2020.01.009. Could the authors clarify if these were the same experiments? There is no indication that the figures were re-used or that the figures are not original.  , 
 Figure 1. * The Western blots here are shown in the  ransom note style that most journals now prohibit, because it is not clear if the lanes were run on the same gel, or if they were exposed for the same time, or if they are of the same molecular weight. They are also cropped very tightly around the bands. * Boxes of the same color highlight bands that look more similar to each other than expected. Could the authors please show the original blots to take away these concerns?  , 
 Figure 5. * Some bands appear to look more similar to each other than expected. Colors do not correspond to those used in previous posts above. There might be more similarities than marked.  , 
 Dear Dr. Tavsan, Thank you very much for your comment. Unfortunately, your reply did not answer my question, nor did it take away any of my concerns. These band similarities are actually not expected to be similar. Can you please show us the original and uncropped blots? This is a very recent paper, so I assume you would still have them. , 
 #3 Thank you for your attention. The band similarities were expected in WB experiments. The first reason is that the treatments didn t change the expressions of the studied proteins. The second reason is that we just used chemicals to change the conformational form of the studied proteins and they give us approximate information. It was obvious from the different articles about these chemicals. The immunoprecipitation experiment just gave us information about whether these molecules had complexes or not by using different groups on these proteins. If you see similar bands, it means the proteins didn t use the studied functional groups to make protein-protein complexes. Consequently, you will see the same band as the control groups (lane h). , 
 #5 The paper was published in 2020, but we made experiments 3 years ago. Since 2018, we have tried to publish the article. We sent the article and waited for evaluation for about 8-9 months. I will try to find the original blots to share with you. Thank you again. ,