MicroRNA-33b suppresses the proliferation and metastasis of hepatocellular carcinoma cells through the inhibition of Sal-like protein 4 expression
Authors: Jingling Yang
Furong Dai
Zhigang Sun
Yun Liu
Zhiqing Song
Tuankui Guo
Yuguo Zhang
Jing Zhang
Yanting Wu
Qinggang Tian
Yao Xiao
Wenfeng Gao
Journal: International Journal of Molecular Medicine (2016)
Discipline: CLINICAL MEDICINE
Keywords: MicroRNAs; miR‑33b; hepatocellular carcinoma; HCC; SALL4
Affiliations: Department of General Surgery, The 4th Affiliated Hospital of Baotou Medical College, Baotou, Inner Mongolia 014040, P.R. China., Department of Hepatobiliary and Pancreatic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China., Department of General Surgery, The Third Clinical Medical School of Inner Mongolia Medical University (Baogang Hospital of Inner Mongolia), Baotou, Inner Mongolia 014010, P.R. China., Department of Neurosurgery, Baotou Eighth Hospital, Baotou, Inner Mongolia 014040, P.R. China.

Abstract:  MicroRNAs (miRNAs or miRs) have been found to participate in the development and malignant progression of human cancers by negatively mediating the expression of their target genes. Recently, miR‑33b has been reported to be involved in multiple types of human cancer, including hepatocellular carcinoma (HCC). However, the underlying regulatory mechanisms of miR‑33b in HCC cell growth and metastasis remain largely unclear. In the present study, RT-qPCR revealed that miR‑33b was significantly downregulated in HCC tissues compared to their matched adjacent normal tissues. Moreover, the miR‑33b level was significantly lower in advanced-stage HCC (stages T3-T4) compared to early-stage HCC (stages T1-T2). Furthermore, it was also downregulated in the HCC cell lines, LH86, HepG2, LMH and PLHC-1, when compared with the THLE-3 normal human liver cells. We further demonstrated that the overexpression of miR‑33b led to a significant decrease in the proliferation, migration and invasion of HepG2 and LH86 cells. Luciferase reporter assay identified Sal-like protein 4 (SALL4) as a target gene of miR‑33b, and its protein expression was negatively regulated by miR‑33b in HepG2 and LH86 cells. Moreover, the restoration of SALL4 expression markedly reversed the inhibitory effect of miR‑33b overexpression on the proliferation, migration and invasion of HepG2 and LH86 cells, indicating that SALL4 is involved in miR‑33b-mediated malignant phenotypes of HCC cells. Furthermore, we found that SALL4 was significantly upregulated in HCC tissues compared to their matched adjacent normal tissues, and its increased expression was significantly associated with the advanced malignancy of HCC. Moreover, SALL4 was also upregulated in HCC cell lines compared to the THLE-3 normal human liver cells. Finally, we found that the SALL4 expression inversely correlated with the miR‑33b level in HCC tissues. On the whole, the findings of our study demonstrate that miR‑33b suppresses the proliferation and metastasis of HCC cells through the inhibition of SALL4 expression. Therefore, miR‑33b/SALL4 may become a potential therapeutic target for the treatment of HCC. 

Retracted: Yes

PubPeer comments:
 Figs 2D, 4C. ![] In 2D, the two miR-NC panels overlap (light blue rectangles), and the two miR-33b panels are the same with minor changes. More to the point, these panels reappear across dozens of other papers, variously labeled. For comparison: Fig 3 C D from [Zhang et al (2016)] .  Transwell assay were performed to examine the migratory and invasive capacities of Saos-2 and U2OS cells transfected with miR-205 mimic or miR-negative control (NC) mimic , and Fig 7C D,  Transwell assay were performed to examine cell migration and invasion of MG63 or U2OS cells transfected with miR-205 mimic, or co-transfected with miR-205 mimic and RUNX2 plasmid . ![] Also *[above]* Fig 4C from [Lai, Chen Li (2015)] .  a Transwell assay were performed to examine the cell proliferation of AGS cells transfected with miR-133a mimics, miR-133a inhibitor, or co-transfected with miR-133a mimics and FSCN1 plasmid. Control: AGS cells without any transfection. *[below]* Figs 3(B), 6(B) from [Shi et al (2015)] .  Transwell assay was performed to determine the invasive capacity of the Saos-2 and U-2 OS cells transfected with NC scramble miRNA or miR-204 mimics, respectively. Control, Saos-2 and U-2 OS cells without any transfection ...  Transwell assay was performed to determine the invasive capacity of the Saos-2 and U-2 OS cells transfected with Sirt1 siRNA or co-transfected with miR-204 mimics and the Sirt1 plasmid, respectively. Control, Saos-2 and U-2 OS cells without any transfection . ![file] , 
 Retracted [12 July 2021] . ------------------------------------------- Following the publication of this paper, it was drawn to the Editors attention by a concerned reader that certain of the Transwell cell migration data shown in Figs. 2D and 4C were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to *International Journal of Molecular Medicine*, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. ,