MiR-126 regulates proliferation and invasion in the bladder cancer BLS cell line by targeting the <em>PIK3R2</em>-mediated PI3K/Akt signaling pathway
Authors: Huan-Yi Lin
Jun Xiao
Yu-Ping Zhu
Yuan-Yuan Zhu
Ling-Wu Chen
Journal: OncoTargets and Therapy (2016)
Discipline: CLINICAL MEDICINE
Keywords: PI3K/Akt signaling pathway; PIK3R2; apoptosis; human bladder BLS cell line; microRNA-126
Affiliations: Department of Urology, Anhui Provincial Hospital, Anhui Medical University, Hefei., Department of Urology, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou., Clinical Laboratory, Anhui Provincial Hospital, Anhui Medical University, Hefei, People's Republic of China.

Abstract:  Objective: To assess whether microRNA-126 (miR-126) targets phosphatidylinositol 3-kinase regulatory subunit beta (PIK3R2) and to determine the potential roles of miR-126 in regulating proliferation and invasion via the PIK3R2-mediated phosphatidylinositol 3 kinase (PI3K)-protein kinase B (Akt) signaling pathway in the human bladder BLS cell line. Materials and methods: A recombinant lentivirus (Lv) vector expressing miR-216 (Lv-miR-126) was successfully constructed, and Lv-miR-126 and Lv vector were transfected into the BLS cell line. A direct regulatory relationship between miR-126 and the PIK3R2 gene was demonstrated by luciferase reporter assays. To determine whether PIK3R2 directly participates in the miR-126-induced effects in BLS cells, anti-miR-126 and a PIK3R2 small interfering RNA (siRNA) were transfected into the BLS cells. Quantitative real-time polymerase chain reaction was used to measure miR-126 and PIK3R2 expressions. 5-Ethynyl-2'-deoxyuridine and colony formation assays to assess cell proliferation, flow cytometry for cell apoptosis and cell cycle analysis, Transwell assays for cell migration and invasion, and Western blots for PIK3R2, PI3K, phosphorylated PI3K (p-PI3K), Akt, and phosphorylated Akt (p-Akt) protein expressions were performed. Results: Lv-miR-126 significantly enhanced the relative expression of miR-126 in the BLS cells after infection (P&lt;0.0001). MiR-126 overexpression inhibited the proliferation, cloning, migration, and invasion of BLS cells, promoted cell apoptosis, and induced S phase arrest (all P&lt;0.05). PIK3R2, p-PI3K, and p-Akt protein expressions were significantly decreased in the BLS cells infected with Lv-miR-126. Luciferase assays showed that miR-126 significantly inhibited the PIK3R2 3' untranslated region (3'UTR) luciferase reporter activity (P&lt;0.05). The anti-miR-126 + PIK3R2 siRNA group had significantly decreased PIK3R2, p-PI3K, and p-Akt expressions compared with those of anti-miR-126 alone, as well as significantly decreased proliferation, invasion, and metastasis and increased apoptosis compared with the anti-miR-126 group (all P&lt;0.05). Additionally, proliferation, invasion, and metastasis were significantly increased, and cell apoptosis was decreased compared with the PIK3R2 siRNA group (all P&lt;0.05). Conclusion: Overexpression of miR-126 negatively regulated the target gene PIK3R2 and further inhibited the PI3K/Akt signaling pathway, thereby inhibiting proliferation, migration, and invasion and promoting apoptosis in BLS cells. 

Retracted: Yes

PubPeer comments:
 Fig 4(B)  effect of miR-126 on the invasion of BLS cells in the BLS-Lv-miR126 group, the BLS-Lv-vector group, and the blank group . Overlap marked. ![file] Fig 4(A), with rotated panels: ![file] Panels appear to be enlarged details of panels in Fig 3B of [Wang et al (2017)] . ![file] Pointed out by a colleague on social media, who has been too busy to post the observation in person. , 
 Fig 8A. Overlap marked. ![file] Fig 8B. Three panels overlap. The remaining panel contains **internal** duplications. ![file] , 
 Above, Fig 7C. Below, Fig 3C, flipped vertically because that is how I roll. ![file] Unexpectedly similar pairs of apoptosis scatterplots marked. , 
 #1 Only just noticed this. Fig 4B again. ![file] Below, Fig 5D from [Xie et al (2017)] . , 
 Retracted [10 March 2021] . ------------------------------------------- The Editor and Publisher of OncoTargets and Therapy wish to retract the published article. It came to our attention that several figures within the paper appeared to be duplicated, specifically: - Figure 4A panels Noninfected and BLS-Lv-vector appear to be duplicated with images from Figure 3B panels Control and NC from Wang et al: MicroRNA-200b inhibits pituitary tumor cell proliferation and invasion by targeting PKCu03b1 . - Figure 4A panel BLS-Lv-miR126 appears to be duplicated with an image from Figure 3B panel Mimics from Wang et al: MicroRNA-200b inhibits pituitary tumor cell proliferation and invasion by targeting PKCu03b1 . - Figure 8A, the two right panels appear to be duplicated. -Figure 8B, the two left panels and the far right panel appear to be duplicated. We attempted to contact the authors of this article but despite multiple attempts received no response. The Editor has determined the findings of the study are no longer valid and requested for the article to be retracted. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. ,