Long Noncoding RNA LINC003121 Inhibits Proliferation and Invasion of Thyroid Cancer Cells by Suppression of the Phosphatidylinositol-3-Kinase (PI3K)/Akt Signaling Pathway
Authors: Kai Liu
Jian Zhang
Hengtao Zhu
Xiang Min
Journal: Medical Science Monitor (2018)
Discipline: CLINICAL MEDICINE
Keywords: lncRNA; LINC003121; thyroid cancer; proliferation; invasion
Affiliations: Department of Otorhinolaryngology and Head and Neck Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China (mainland)

Abstract:  BACKGROUND The aim of this study was to explore the potential effects of long noncoding RNA (lncRNA) LINC003121 on thyroid cancer (TC) cell proliferation and invasion and to explore their possible mechanisms with the involvement of the PI3K/Akt signaling pathway. MATERIAL AND METHODS We enrolled 211 thyroid cancer tissues and 70 adjacent normal tissues in this study. TC cell lines K1, SW579, and 8505C and the human thyroid follicular cell line Nthy-ori3-1 were selected and assigned into blank, control vectors, LINC00312 vectors, si-control, and si-LINC00312 groups. Quantitative real-time PCR was used to determine the levels of LINC003121 and Western blotting was used to detect the protein expression of MMP-9, PI3K, t-Akt, and p-Akt. Cell proliferation was assessed by CCK8 assay and EdU incorporation assay, and cell invasion was assessed by Transwell assay. RESULTS The expression of LINC00312 was significantly decreased in TC tissues and cell lines. In an in vitro experiment, si-LINC00312 significantly promoted the invasion and proliferation of TC cells. Conversely, overexpression of LINC00312 decreased cell proliferation and invasion in vitro, and decreased tumorigenicity in TC xenograft models in nude mice. LINC00312-mediated tumor suppression in TC cells may occur via suppression of activation of the PI3K/Akt signaling pathway and expression of MMP-9, and the role of MMP-9 expression induced by overexpressed LINC00312 or si-LINC00312 could be weakened by LY294002 (PI3K inhibitor). CONCLUSIONS LINC00312 can act as a tumor-suppressor in TC by attenuating the PI3K/Akt signaling pathway, and LINC00312 could be a novel diagnosis biomarker and a promising therapeutic target for TC patients. 

Retracted: No

PubPeer comments:
 Fig 3C.  The invasive ability of the cells in each group was observed by microscope, and the number of invasive cells in each group was counted. . Authors may wish to check - I do not think that all the panels represent different groups. ![file] , 
 Found a couple more. ![file] , 
 In addiction there is one panel similar to [Ran et al, 2018] ![file] ![file] , 
 Another one similar to [Song et al, 2019] From Song et al paper: ![file] From this paper: ![file] , 
 Another one [Xu et al, 2018] See the blue one. ![file] Figure from this one: ![file] , 
 Switching to gray tones to show overlaps *within* 3C and including all of Edentulina Martensi s findings so far, we now have this. ![file] Yellow box for another overlap with Xu et al. ![] I have added a green box to show the overlap with Fig 6A of [Zou et al (2017)] . ![file] , 
 #6 ![] Yellow and dark blue boxes are also direct (though rotated stretched) overlaps between the present figure and 6A of Zou et al... ![file] ...as a corollary of the rotated overlap (light blue box, Edentulina Martensi s observation) between Zou et al s 6A, and [Xu et al (2018)] . ![] , 
 Dear professors, Thanks a lot for pointing out our mistake. We realized that in the process of preparing these figures, we confused the rpresentative images when we copied and pasted them. For this reason, we have contacted the editor of the journal to correct these errors.Thank you again for your valuable advices. We are very sorry for our mistakes. , 
 #8 But how did you  confuse the representative images with a set used by at least four other teams of authors? , 
 No sign of a correction at the journal. , 
 Retracted [6 August 2021] .  This article is retracted due to serious flaws detected on figures. ,