Effects of SOST Gene Silencing on Proliferation, Apoptosis, Invasion, and Migration of Human Osteosarcoma Cells Through the Wnt/β-Catenin Signaling Pathway
Authors: Xiao-Lin Li
Wei Zhang
Jian Zou
Journal: Calcified tissue international (2017)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Osteosarcoma cells; SOST gene silencing; Wnt/β-catenin signaling pathway.
Affiliations: Department of Orthopedics, Shanghai Jiaotong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, Shanghai, 200233, People's Republic of China., Department of Orthopedics, Shanghai Jiaotong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, Shanghai, 200233, People's Republic of China. .

Abstract:  Our study explored the effects of SOST gene silencing on the proliferation, apoptosis, invasion, and migration of human osteosarcoma cells through Wnt/β-catenin signaling pathway. Fresh tissues were obtained from 108 patients with osteosarcoma and 46 patients with osteochondroma. Human osteosarcoma cells (MG-63, U2-OS, HOS, and Saos-2) and normal osteoblast (hFoB1.19) were selected and cultured. Osteosarcoma cells were grouped randomly into the blank group, the scrambled control group, and the SOST-siRNA group. Cell proliferation was determined by MTT assay. Cell cycle and apoptosis were tested by flow cytometry. Transwell and scratch test were performed to determine cell invasion and migration. The qRT-PCR and Western blotting were used to detect mRNA and protein expression level of sclerostin, Wnt1, β-catenin, C-Myc, Cyclin D1, and MMP-7. The activity of caspase-3 was assessed by immunocytochemistry. Alkaline phosphatase (ALP) activity was measured using P-nitrophenylphosphate as a substrate. Low SOST mRNA and sclerostin protein expression levels were observed in osteosarcoma tissues and cells. Compared with the blank and scrambled control groups, sclerostin expression, apoptotic cells, ALP activity, and caspase-3 activity were down-regulated, while the proliferation, invasion, and migration abilities of osteosarcoma cells were evidently enhanced in the SOST-siRNA group. After SOST gene silencing, the mRNA and protein expression levels of Wnt1, β-catenin, C-Myc, Cyclin D1, and MMP-7 in osteosarcoma cells and β-catenin protein expression levels in the nucleus and cytoplasm were significantly elevated. SOST gene silencing promotes the proliferation, invasion, and migration, and inhibits apoptosis of osteosarcoma cells by activating Wnt/β-catenin signaling pathway. 

Retracted: No

PubPeer comments:
  Fig. 4 Cell cycle distributions of MG-63 cells among the blank, scrambled control, and SOST-siRNA groups. Notes A cell cycle distributions of MG-63 cells among the blank group (without transfection), the scrambled control group (transfected with the negative control siRNA plasmid) and the SOST-siRNA group (transfected with the SOST-siRNA plasmid) . ![file] These are strange overhanging histograms and I have to wonder about the software used to generate and plot them. , 
 Fig 6A.  Invasion abilities of MG-63 cells among the blank, scrambled control, and SOST-siRNA groups. Notes A the micrographs of MG-63 cells with crystal violet staining in transwell assay : ![file] Overlap with Fig 17A of [Xu et al (2018)] : ![file] , 
 Fig 6A again: ![file] Green box shows overlap with Fig 3A of [Min et al (2018)] . ![] , 
 Another one. From [Xu et al,2018] Light blue. ![file] ![file] Zoomed in and rotated: ![file] , 
 #4 Corollary: the present Fig 6A now looks like this: ![] to show all the overlaps with [Min et al (2018)] . ![] We are running out of colors. ,