Suppression of SIPA-1 expression may reduce bladder cancer invasion and metastasis via the downregulation of E-cadherin and ZO-1
Authors: Xinghuan Wang
Ping Zhang
Journal: Experimental and therapeutic medicine (2016)
Discipline: CLINICAL MEDICINE
Keywords: bladder cancer; invasion; metastasis; signal-induced proliferation-associated protein 1.

Abstract:  The aim of the present study was to investigate the capacity of signal-induced proliferation-associated protein 1 (SIPA-1) to regulate bladder cancer cell invasion and metastasis. BIU-87 and T24 cells were transfected with the SIPA gene and SIPA short hairpin (sh)RNA, respectively. Western blot analysis was conducted to analyze the expression levels of SIPA-1, Ras-related protein 1 (Rap1), Rap1 guanosine triphosphate (Rap1GTP), E-cadherin and zona occludens-1 (ZO-1). Cell motility and invasion were evaluated in vitro using wound and Transwell assays. Transfected cells were inoculated into the pelvic region of BALB/c nude mice, and the number of resulting tumors was recorded after 6 weeks. Western blot analysis revealed that expression levels of E-cadherin and ZO-1 were reduced in the cells with enhanced levels of SIPA-1. By contrast, the levels of E-cadherin and ZO-1 were elevated in the cells in which SIPA-1 was knocked down. In comparison with untransfected cells, the cells with reduced levels of SIPA-1 exhibited reduced wound closure and fewer cells crossed the chamber in the Transwell experiment, whereas the cells with enhanced levels of SIPA-1 exhibited increased migration and invasion In vivo, an increased tumor count was obtained in the mice with elevated levels of SIPA-1. Therefore, the results of the present study indicate that SIPA-1 is able to regulate bladder cancer cell metastasis and invasion by reducing the expression of E-cadherin and ZO-1. 

Retracted: No

PubPeer comments:
 This paper was found during a systematic search of papers in this journal with possible duplicated images. About 10% of the papers in this journal (n=169 examined) were found to contain inappropriately duplicated images. These papers have all been reported to the journal publisher in 2017. The editors promised to  investigate promptly but no action has been taken as of today. Figure 2B. * Yellow boxes: Two panels appear to show an area of overlap. ![file] , 
 Figure 3A. * Blue boxes: Two panels appear to show an area of overlap. ![file] , 
 Corrigendum, [23 September 2022] .  Subsequently to the publication of the above article, an interested reader drew to the authorsu2019 attention that Figs. 2 and 3 in their paper were published with errors that arose inadvertently during the assembly of these figures. In Fig. 2B, there was an apparent overlap in data comparing between the u2018BIUu201187, 24 hu2019 and u2018Control BIUu201187, 24 hu2019 data panels, whereas in Fig. 3A, there was an apparent overlapping section of data comparing between the u2018Invasion, T24u2019 and u2018Invasion, Control T24u2019 data panels. However, after having consulted their original data, the authors realized where the errors occurred in assembling these figures. New versions of Figs. 2 and 3, showing replacement data for the experiments portrayed in the affected figure parts (Figs. 2B and 3A), are shown on the next page. Note that the revised data shown for these figures do not affect the overall conclusions reported in the paper. All the authors agree with the publication of this corrigendum; furthermore, they apologize to the Editor of *Experimental and Therapeutic Medicine* and to the readership for any inconvenience caused. ,